2005-04-16 16:20:36 -06:00
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/*
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2005-11-01 20:58:39 -07:00
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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2005-04-16 16:20:36 -06:00
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*
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2005-11-01 20:58:39 -07:00
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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2005-04-16 16:20:36 -06:00
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* published by the Free Software Foundation.
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*
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2005-11-01 20:58:39 -07:00
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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2005-04-16 16:20:36 -06:00
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*
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2005-11-01 20:58:39 -07:00
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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2005-04-16 16:20:36 -06:00
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*/
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#include "xfs.h"
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2005-11-01 20:38:42 -07:00
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#include "xfs_bit.h"
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2005-04-16 16:20:36 -06:00
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#include "xfs_log.h"
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2005-11-01 20:38:42 -07:00
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#include "xfs_inum.h"
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2005-04-16 16:20:36 -06:00
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#include "xfs_sb.h"
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2005-11-01 20:38:42 -07:00
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#include "xfs_ag.h"
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2005-04-16 16:20:36 -06:00
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#include "xfs_trans.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_dinode.h"
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#include "xfs_inode.h"
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2012-03-13 02:41:05 -06:00
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#include "xfs_inode_item.h"
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2005-11-01 20:38:42 -07:00
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#include "xfs_alloc.h"
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2005-04-16 16:20:36 -06:00
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#include "xfs_error.h"
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#include "xfs_rw.h"
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#include "xfs_iomap.h"
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2007-08-28 18:58:01 -06:00
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#include "xfs_vnodeops.h"
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2009-12-14 16:14:59 -07:00
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#include "xfs_trace.h"
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2010-03-04 19:00:42 -07:00
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#include "xfs_bmap.h"
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
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#include <linux/gfp.h>
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2005-04-16 16:20:36 -06:00
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#include <linux/mpage.h>
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2006-01-11 02:48:14 -07:00
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#include <linux/pagevec.h>
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2005-04-16 16:20:36 -06:00
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#include <linux/writeback.h>
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2009-12-14 16:14:59 -07:00
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void
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2006-03-13 19:26:27 -07:00
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xfs_count_page_state(
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struct page *page,
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int *delalloc,
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int *unwritten)
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{
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struct buffer_head *bh, *head;
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2010-06-23 17:46:01 -06:00
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*delalloc = *unwritten = 0;
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2006-03-13 19:26:27 -07:00
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bh = head = page_buffers(page);
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do {
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2010-06-23 17:46:01 -06:00
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if (buffer_unwritten(bh))
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2006-03-13 19:26:27 -07:00
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(*unwritten) = 1;
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else if (buffer_delay(bh))
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(*delalloc) = 1;
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} while ((bh = bh->b_this_page) != head);
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}
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2007-09-13 23:23:17 -06:00
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STATIC struct block_device *
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xfs_find_bdev_for_inode(
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2010-04-28 06:28:52 -06:00
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struct inode *inode)
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2007-09-13 23:23:17 -06:00
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{
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2010-04-28 06:28:52 -06:00
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struct xfs_inode *ip = XFS_I(inode);
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2007-09-13 23:23:17 -06:00
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struct xfs_mount *mp = ip->i_mount;
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2007-11-22 22:29:42 -07:00
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if (XFS_IS_REALTIME_INODE(ip))
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2007-09-13 23:23:17 -06:00
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return mp->m_rtdev_targp->bt_bdev;
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else
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return mp->m_ddev_targp->bt_bdev;
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}
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2006-01-10 21:40:13 -07:00
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/*
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* We're now finished for good with this ioend structure.
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* Update the page state via the associated buffer_heads,
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* release holds on the inode and bio, and finally free
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* up memory. Do not use the ioend after this.
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*/
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2005-09-02 00:58:49 -06:00
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STATIC void
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xfs_destroy_ioend(
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xfs_ioend_t *ioend)
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{
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2006-01-10 21:40:13 -07:00
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struct buffer_head *bh, *next;
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for (bh = ioend->io_buffer_head; bh; bh = next) {
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next = bh->b_private;
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2006-06-08 22:58:38 -06:00
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bh->b_end_io(bh, !ioend->io_error);
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2006-01-10 21:40:13 -07:00
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}
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2008-12-03 04:20:38 -07:00
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2011-08-23 02:28:10 -06:00
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if (ioend->io_iocb) {
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2011-08-23 23:59:25 -06:00
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if (ioend->io_isasync) {
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aio_complete(ioend->io_iocb, ioend->io_error ?
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ioend->io_error : ioend->io_result, 0);
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}
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2011-08-23 02:28:10 -06:00
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inode_dio_done(ioend->io_inode);
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}
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2011-08-23 02:28:13 -06:00
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2005-09-02 00:58:49 -06:00
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mempool_free(ioend, xfs_ioend_pool);
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}
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2011-08-23 02:28:11 -06:00
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/*
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* Fast and loose check if this write could update the on-disk inode size.
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*/
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static inline bool xfs_ioend_is_append(struct xfs_ioend *ioend)
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{
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return ioend->io_offset + ioend->io_size >
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XFS_I(ioend->io_inode)->i_d.di_size;
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}
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2012-03-13 02:41:05 -06:00
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STATIC int
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xfs_setfilesize_trans_alloc(
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struct xfs_ioend *ioend)
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{
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struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
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struct xfs_trans *tp;
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int error;
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tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
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error = xfs_trans_reserve(tp, 0, XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
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if (error) {
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xfs_trans_cancel(tp, 0);
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return error;
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}
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ioend->io_append_trans = tp;
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/*
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* We hand off the transaction to the completion thread now, so
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* clear the flag here.
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*/
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current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
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return 0;
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}
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|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
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/*
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2011-12-18 13:00:12 -07:00
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* Update on-disk file size now that data has been written to disk.
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
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*/
|
2012-03-13 02:41:05 -06:00
|
|
|
STATIC int
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
xfs_setfilesize(
|
2012-02-29 02:53:48 -07:00
|
|
|
struct xfs_ioend *ioend)
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
{
|
2012-02-29 02:53:48 -07:00
|
|
|
struct xfs_inode *ip = XFS_I(ioend->io_inode);
|
2012-03-13 02:41:05 -06:00
|
|
|
struct xfs_trans *tp = ioend->io_append_trans;
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
xfs_fsize_t isize;
|
|
|
|
|
2012-03-13 02:41:05 -06:00
|
|
|
/*
|
|
|
|
* The transaction was allocated in the I/O submission thread,
|
|
|
|
* thus we need to mark ourselves as beeing in a transaction
|
|
|
|
* manually.
|
|
|
|
*/
|
|
|
|
current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
|
|
|
|
|
2012-02-29 02:53:48 -07:00
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
2012-02-29 02:53:49 -07:00
|
|
|
isize = xfs_new_eof(ip, ioend->io_offset + ioend->io_size);
|
2012-03-13 02:41:05 -06:00
|
|
|
if (!isize) {
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
xfs_trans_cancel(tp, 0);
|
|
|
|
return 0;
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
}
|
|
|
|
|
2012-03-13 02:41:05 -06:00
|
|
|
trace_xfs_setfilesize(ip, ioend->io_offset, ioend->io_size);
|
|
|
|
|
|
|
|
ip->i_d.di_size = isize;
|
|
|
|
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
|
|
|
|
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
|
|
|
|
|
|
|
|
return xfs_trans_commit(tp, 0);
|
2010-02-16 22:36:29 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2010-07-18 15:17:11 -06:00
|
|
|
* Schedule IO completion handling on the final put of an ioend.
|
2011-08-23 02:28:11 -06:00
|
|
|
*
|
|
|
|
* If there is no work to do we might as well call it a day and free the
|
|
|
|
* ioend right now.
|
2010-02-16 22:36:29 -07:00
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_finish_ioend(
|
2010-07-18 15:17:11 -06:00
|
|
|
struct xfs_ioend *ioend)
|
2010-02-16 22:36:29 -07:00
|
|
|
{
|
|
|
|
if (atomic_dec_and_test(&ioend->io_remaining)) {
|
2012-02-29 02:53:48 -07:00
|
|
|
struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
|
|
|
|
|
2010-07-18 15:17:11 -06:00
|
|
|
if (ioend->io_type == IO_UNWRITTEN)
|
2012-02-29 02:53:48 -07:00
|
|
|
queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
|
2012-03-13 02:41:05 -06:00
|
|
|
else if (ioend->io_append_trans)
|
2012-02-29 02:53:48 -07:00
|
|
|
queue_work(mp->m_data_workqueue, &ioend->io_work);
|
2011-08-23 02:28:11 -06:00
|
|
|
else
|
|
|
|
xfs_destroy_ioend(ioend);
|
2010-02-16 22:36:29 -07:00
|
|
|
}
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
}
|
|
|
|
|
2005-09-02 00:58:49 -06:00
|
|
|
/*
|
2009-10-30 03:11:47 -06:00
|
|
|
* IO write completion.
|
2006-01-10 21:40:13 -07:00
|
|
|
*/
|
|
|
|
STATIC void
|
2009-10-30 03:11:47 -06:00
|
|
|
xfs_end_io(
|
2010-02-16 22:36:29 -07:00
|
|
|
struct work_struct *work)
|
2005-09-02 00:58:49 -06:00
|
|
|
{
|
2010-02-16 22:36:29 -07:00
|
|
|
xfs_ioend_t *ioend = container_of(work, xfs_ioend_t, io_work);
|
|
|
|
struct xfs_inode *ip = XFS_I(ioend->io_inode);
|
2010-03-03 17:57:09 -07:00
|
|
|
int error = 0;
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
|
2011-08-23 23:59:25 -06:00
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
2011-11-08 01:56:15 -07:00
|
|
|
ioend->io_error = -EIO;
|
2011-08-23 23:59:25 -06:00
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
if (ioend->io_error)
|
|
|
|
goto done;
|
|
|
|
|
2009-10-30 03:11:47 -06:00
|
|
|
/*
|
|
|
|
* For unwritten extents we need to issue transactions to convert a
|
|
|
|
* range to normal written extens after the data I/O has finished.
|
|
|
|
*/
|
2011-08-23 23:59:25 -06:00
|
|
|
if (ioend->io_type == IO_UNWRITTEN) {
|
2012-03-13 02:41:05 -06:00
|
|
|
/*
|
|
|
|
* For buffered I/O we never preallocate a transaction when
|
|
|
|
* doing the unwritten extent conversion, but for direct I/O
|
|
|
|
* we do not know if we are converting an unwritten extent
|
|
|
|
* or not at the point where we preallocate the transaction.
|
|
|
|
*/
|
|
|
|
if (ioend->io_append_trans) {
|
|
|
|
ASSERT(ioend->io_isdirect);
|
|
|
|
|
|
|
|
current_set_flags_nested(
|
|
|
|
&ioend->io_append_trans->t_pflags, PF_FSTRANS);
|
|
|
|
xfs_trans_cancel(ioend->io_append_trans, 0);
|
|
|
|
}
|
|
|
|
|
2009-10-30 03:11:47 -06:00
|
|
|
error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
|
|
|
|
ioend->io_size);
|
2011-08-23 23:59:25 -06:00
|
|
|
if (error) {
|
|
|
|
ioend->io_error = -error;
|
|
|
|
goto done;
|
|
|
|
}
|
2012-03-13 02:41:05 -06:00
|
|
|
} else if (ioend->io_append_trans) {
|
|
|
|
error = xfs_setfilesize(ioend);
|
|
|
|
if (error)
|
|
|
|
ioend->io_error = -error;
|
2012-02-29 02:53:50 -07:00
|
|
|
} else {
|
2012-03-13 02:41:05 -06:00
|
|
|
ASSERT(!xfs_ioend_is_append(ioend));
|
2009-10-30 03:11:47 -06:00
|
|
|
}
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
|
2011-08-23 23:59:25 -06:00
|
|
|
done:
|
2012-02-29 02:53:48 -07:00
|
|
|
xfs_destroy_ioend(ioend);
|
2009-04-06 10:42:11 -06:00
|
|
|
}
|
|
|
|
|
2010-07-18 15:17:11 -06:00
|
|
|
/*
|
|
|
|
* Call IO completion handling in caller context on the final put of an ioend.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_finish_ioend_sync(
|
|
|
|
struct xfs_ioend *ioend)
|
|
|
|
{
|
|
|
|
if (atomic_dec_and_test(&ioend->io_remaining))
|
|
|
|
xfs_end_io(&ioend->io_work);
|
|
|
|
}
|
|
|
|
|
2005-09-02 00:58:49 -06:00
|
|
|
/*
|
|
|
|
* Allocate and initialise an IO completion structure.
|
|
|
|
* We need to track unwritten extent write completion here initially.
|
|
|
|
* We'll need to extend this for updating the ondisk inode size later
|
|
|
|
* (vs. incore size).
|
|
|
|
*/
|
|
|
|
STATIC xfs_ioend_t *
|
|
|
|
xfs_alloc_ioend(
|
2006-01-10 21:40:13 -07:00
|
|
|
struct inode *inode,
|
|
|
|
unsigned int type)
|
2005-09-02 00:58:49 -06:00
|
|
|
{
|
|
|
|
xfs_ioend_t *ioend;
|
|
|
|
|
|
|
|
ioend = mempool_alloc(xfs_ioend_pool, GFP_NOFS);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Set the count to 1 initially, which will prevent an I/O
|
|
|
|
* completion callback from happening before we have started
|
|
|
|
* all the I/O from calling the completion routine too early.
|
|
|
|
*/
|
|
|
|
atomic_set(&ioend->io_remaining, 1);
|
2011-08-23 02:28:10 -06:00
|
|
|
ioend->io_isasync = 0;
|
2012-03-13 02:41:05 -06:00
|
|
|
ioend->io_isdirect = 0;
|
2006-06-08 22:58:38 -06:00
|
|
|
ioend->io_error = 0;
|
2006-01-10 21:40:13 -07:00
|
|
|
ioend->io_list = NULL;
|
|
|
|
ioend->io_type = type;
|
2007-08-28 19:46:28 -06:00
|
|
|
ioend->io_inode = inode;
|
2005-09-04 16:23:35 -06:00
|
|
|
ioend->io_buffer_head = NULL;
|
2006-01-10 21:40:13 -07:00
|
|
|
ioend->io_buffer_tail = NULL;
|
2005-09-02 00:58:49 -06:00
|
|
|
ioend->io_offset = 0;
|
|
|
|
ioend->io_size = 0;
|
2010-07-18 15:17:10 -06:00
|
|
|
ioend->io_iocb = NULL;
|
|
|
|
ioend->io_result = 0;
|
2012-03-13 02:41:05 -06:00
|
|
|
ioend->io_append_trans = NULL;
|
2005-09-02 00:58:49 -06:00
|
|
|
|
2009-10-30 03:11:47 -06:00
|
|
|
INIT_WORK(&ioend->io_work, xfs_end_io);
|
2005-09-02 00:58:49 -06:00
|
|
|
return ioend;
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
STATIC int
|
|
|
|
xfs_map_blocks(
|
|
|
|
struct inode *inode,
|
|
|
|
loff_t offset,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2010-12-10 01:42:20 -07:00
|
|
|
int type,
|
|
|
|
int nonblocking)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-12-10 01:42:20 -07:00
|
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
|
|
struct xfs_mount *mp = ip->i_mount;
|
2010-12-10 01:42:22 -07:00
|
|
|
ssize_t count = 1 << inode->i_blkbits;
|
2010-12-10 01:42:20 -07:00
|
|
|
xfs_fileoff_t offset_fsb, end_fsb;
|
|
|
|
int error = 0;
|
|
|
|
int bmapi_flags = XFS_BMAPI_ENTIRE;
|
|
|
|
int nimaps = 1;
|
|
|
|
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
|
|
return -XFS_ERROR(EIO);
|
|
|
|
|
2010-12-10 01:42:21 -07:00
|
|
|
if (type == IO_UNWRITTEN)
|
2010-12-10 01:42:20 -07:00
|
|
|
bmapi_flags |= XFS_BMAPI_IGSTATE;
|
2010-12-10 01:42:21 -07:00
|
|
|
|
|
|
|
if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
|
|
|
|
if (nonblocking)
|
|
|
|
return -XFS_ERROR(EAGAIN);
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_SHARED);
|
2010-12-10 01:42:20 -07:00
|
|
|
}
|
|
|
|
|
2010-12-10 01:42:21 -07:00
|
|
|
ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
|
|
|
|
(ip->i_df.if_flags & XFS_IFEXTENTS));
|
2010-12-10 01:42:20 -07:00
|
|
|
ASSERT(offset <= mp->m_maxioffset);
|
2010-12-10 01:42:21 -07:00
|
|
|
|
2010-12-10 01:42:20 -07:00
|
|
|
if (offset + count > mp->m_maxioffset)
|
|
|
|
count = mp->m_maxioffset - offset;
|
|
|
|
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
|
|
|
|
offset_fsb = XFS_B_TO_FSBT(mp, offset);
|
2011-09-18 14:40:45 -06:00
|
|
|
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
|
|
|
|
imap, &nimaps, bmapi_flags);
|
2010-12-10 01:42:21 -07:00
|
|
|
xfs_iunlock(ip, XFS_ILOCK_SHARED);
|
2010-12-10 01:42:20 -07:00
|
|
|
|
2010-12-10 01:42:21 -07:00
|
|
|
if (error)
|
|
|
|
return -XFS_ERROR(error);
|
2010-12-10 01:42:20 -07:00
|
|
|
|
2010-12-10 01:42:21 -07:00
|
|
|
if (type == IO_DELALLOC &&
|
|
|
|
(!nimaps || isnullstartblock(imap->br_startblock))) {
|
2010-12-10 01:42:20 -07:00
|
|
|
error = xfs_iomap_write_allocate(ip, offset, count, imap);
|
|
|
|
if (!error)
|
|
|
|
trace_xfs_map_blocks_alloc(ip, offset, count, type, imap);
|
2010-12-10 01:42:21 -07:00
|
|
|
return -XFS_ERROR(error);
|
2010-12-10 01:42:20 -07:00
|
|
|
}
|
|
|
|
|
2010-12-10 01:42:21 -07:00
|
|
|
#ifdef DEBUG
|
|
|
|
if (type == IO_UNWRITTEN) {
|
|
|
|
ASSERT(nimaps);
|
|
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
if (nimaps)
|
|
|
|
trace_xfs_map_blocks_found(ip, offset, count, type, imap);
|
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2009-11-14 09:17:22 -07:00
|
|
|
STATIC int
|
2010-04-28 06:28:58 -06:00
|
|
|
xfs_imap_valid(
|
2010-04-28 06:28:54 -06:00
|
|
|
struct inode *inode,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2010-04-28 06:28:58 -06:00
|
|
|
xfs_off_t offset)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-04-28 06:28:58 -06:00
|
|
|
offset >>= inode->i_blkbits;
|
2010-04-28 06:28:54 -06:00
|
|
|
|
2010-04-28 06:28:58 -06:00
|
|
|
return offset >= imap->br_startoff &&
|
|
|
|
offset < imap->br_startoff + imap->br_blockcount;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2006-01-10 21:40:13 -07:00
|
|
|
/*
|
|
|
|
* BIO completion handler for buffered IO.
|
|
|
|
*/
|
2007-10-12 00:17:47 -06:00
|
|
|
STATIC void
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_end_bio(
|
|
|
|
struct bio *bio,
|
|
|
|
int error)
|
|
|
|
{
|
|
|
|
xfs_ioend_t *ioend = bio->bi_private;
|
|
|
|
|
|
|
|
ASSERT(atomic_read(&bio->bi_cnt) >= 1);
|
2006-06-08 22:58:38 -06:00
|
|
|
ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error;
|
2006-01-10 21:40:13 -07:00
|
|
|
|
|
|
|
/* Toss bio and pass work off to an xfsdatad thread */
|
|
|
|
bio->bi_private = NULL;
|
|
|
|
bio->bi_end_io = NULL;
|
|
|
|
bio_put(bio);
|
2006-06-08 22:58:38 -06:00
|
|
|
|
2010-07-18 15:17:11 -06:00
|
|
|
xfs_finish_ioend(ioend);
|
2006-01-10 21:40:13 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
STATIC void
|
|
|
|
xfs_submit_ioend_bio(
|
2009-10-30 03:09:15 -06:00
|
|
|
struct writeback_control *wbc,
|
|
|
|
xfs_ioend_t *ioend,
|
|
|
|
struct bio *bio)
|
2006-01-10 21:40:13 -07:00
|
|
|
{
|
|
|
|
atomic_inc(&ioend->io_remaining);
|
|
|
|
bio->bi_private = ioend;
|
|
|
|
bio->bi_end_io = xfs_end_bio;
|
2011-03-09 03:56:30 -07:00
|
|
|
submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE, bio);
|
2006-01-10 21:40:13 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
STATIC struct bio *
|
|
|
|
xfs_alloc_ioend_bio(
|
|
|
|
struct buffer_head *bh)
|
|
|
|
{
|
|
|
|
int nvecs = bio_get_nr_vecs(bh->b_bdev);
|
2010-12-10 01:42:17 -07:00
|
|
|
struct bio *bio = bio_alloc(GFP_NOIO, nvecs);
|
2006-01-10 21:40:13 -07:00
|
|
|
|
|
|
|
ASSERT(bio->bi_private == NULL);
|
|
|
|
bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
|
|
|
|
bio->bi_bdev = bh->b_bdev;
|
|
|
|
return bio;
|
|
|
|
}
|
|
|
|
|
|
|
|
STATIC void
|
|
|
|
xfs_start_buffer_writeback(
|
|
|
|
struct buffer_head *bh)
|
|
|
|
{
|
|
|
|
ASSERT(buffer_mapped(bh));
|
|
|
|
ASSERT(buffer_locked(bh));
|
|
|
|
ASSERT(!buffer_delay(bh));
|
|
|
|
ASSERT(!buffer_unwritten(bh));
|
|
|
|
|
|
|
|
mark_buffer_async_write(bh);
|
|
|
|
set_buffer_uptodate(bh);
|
|
|
|
clear_buffer_dirty(bh);
|
|
|
|
}
|
|
|
|
|
|
|
|
STATIC void
|
|
|
|
xfs_start_page_writeback(
|
|
|
|
struct page *page,
|
|
|
|
int clear_dirty,
|
|
|
|
int buffers)
|
|
|
|
{
|
|
|
|
ASSERT(PageLocked(page));
|
|
|
|
ASSERT(!PageWriteback(page));
|
|
|
|
if (clear_dirty)
|
2006-12-20 16:24:01 -07:00
|
|
|
clear_page_dirty_for_io(page);
|
|
|
|
set_page_writeback(page);
|
2006-01-10 21:40:13 -07:00
|
|
|
unlock_page(page);
|
2007-10-17 00:30:42 -06:00
|
|
|
/* If no buffers on the page are to be written, finish it here */
|
|
|
|
if (!buffers)
|
2006-01-10 21:40:13 -07:00
|
|
|
end_page_writeback(page);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int bio_add_buffer(struct bio *bio, struct buffer_head *bh)
|
|
|
|
{
|
|
|
|
return bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2006-01-17 19:38:12 -07:00
|
|
|
* Submit all of the bios for all of the ioends we have saved up, covering the
|
|
|
|
* initial writepage page and also any probed pages.
|
|
|
|
*
|
|
|
|
* Because we may have multiple ioends spanning a page, we need to start
|
|
|
|
* writeback on all the buffers before we submit them for I/O. If we mark the
|
|
|
|
* buffers as we got, then we can end up with a page that only has buffers
|
|
|
|
* marked async write and I/O complete on can occur before we mark the other
|
|
|
|
* buffers async write.
|
|
|
|
*
|
|
|
|
* The end result of this is that we trip a bug in end_page_writeback() because
|
|
|
|
* we call it twice for the one page as the code in end_buffer_async_write()
|
|
|
|
* assumes that all buffers on the page are started at the same time.
|
|
|
|
*
|
|
|
|
* The fix is two passes across the ioend list - one to start writeback on the
|
2006-03-28 15:55:14 -07:00
|
|
|
* buffer_heads, and then submit them for I/O on the second pass.
|
2006-01-10 21:40:13 -07:00
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_submit_ioend(
|
2009-10-30 03:09:15 -06:00
|
|
|
struct writeback_control *wbc,
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_ioend_t *ioend)
|
|
|
|
{
|
2006-01-17 19:38:12 -07:00
|
|
|
xfs_ioend_t *head = ioend;
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_ioend_t *next;
|
|
|
|
struct buffer_head *bh;
|
|
|
|
struct bio *bio;
|
|
|
|
sector_t lastblock = 0;
|
|
|
|
|
2006-01-17 19:38:12 -07:00
|
|
|
/* Pass 1 - start writeback */
|
|
|
|
do {
|
|
|
|
next = ioend->io_list;
|
2010-12-10 01:42:17 -07:00
|
|
|
for (bh = ioend->io_buffer_head; bh; bh = bh->b_private)
|
2006-01-17 19:38:12 -07:00
|
|
|
xfs_start_buffer_writeback(bh);
|
|
|
|
} while ((ioend = next) != NULL);
|
|
|
|
|
|
|
|
/* Pass 2 - submit I/O */
|
|
|
|
ioend = head;
|
2006-01-10 21:40:13 -07:00
|
|
|
do {
|
|
|
|
next = ioend->io_list;
|
|
|
|
bio = NULL;
|
|
|
|
|
|
|
|
for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
|
|
|
|
|
|
|
|
if (!bio) {
|
|
|
|
retry:
|
|
|
|
bio = xfs_alloc_ioend_bio(bh);
|
|
|
|
} else if (bh->b_blocknr != lastblock + 1) {
|
2009-10-30 03:09:15 -06:00
|
|
|
xfs_submit_ioend_bio(wbc, ioend, bio);
|
2006-01-10 21:40:13 -07:00
|
|
|
goto retry;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (bio_add_buffer(bio, bh) != bh->b_size) {
|
2009-10-30 03:09:15 -06:00
|
|
|
xfs_submit_ioend_bio(wbc, ioend, bio);
|
2006-01-10 21:40:13 -07:00
|
|
|
goto retry;
|
|
|
|
}
|
|
|
|
|
|
|
|
lastblock = bh->b_blocknr;
|
|
|
|
}
|
|
|
|
if (bio)
|
2009-10-30 03:09:15 -06:00
|
|
|
xfs_submit_ioend_bio(wbc, ioend, bio);
|
2010-07-18 15:17:11 -06:00
|
|
|
xfs_finish_ioend(ioend);
|
2006-01-10 21:40:13 -07:00
|
|
|
} while ((ioend = next) != NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Cancel submission of all buffer_heads so far in this endio.
|
|
|
|
* Toss the endio too. Only ever called for the initial page
|
|
|
|
* in a writepage request, so only ever one page.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_cancel_ioend(
|
|
|
|
xfs_ioend_t *ioend)
|
|
|
|
{
|
|
|
|
xfs_ioend_t *next;
|
|
|
|
struct buffer_head *bh, *next_bh;
|
|
|
|
|
|
|
|
do {
|
|
|
|
next = ioend->io_list;
|
|
|
|
bh = ioend->io_buffer_head;
|
|
|
|
do {
|
|
|
|
next_bh = bh->b_private;
|
|
|
|
clear_buffer_async_write(bh);
|
|
|
|
unlock_buffer(bh);
|
|
|
|
} while ((bh = next_bh) != NULL);
|
|
|
|
|
|
|
|
mempool_free(ioend, xfs_ioend_pool);
|
|
|
|
} while ((ioend = next) != NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Test to see if we've been building up a completion structure for
|
|
|
|
* earlier buffers -- if so, we try to append to this ioend if we
|
|
|
|
* can, otherwise we finish off any current ioend and start another.
|
|
|
|
* Return true if we've finished the given ioend.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_add_to_ioend(
|
|
|
|
struct inode *inode,
|
|
|
|
struct buffer_head *bh,
|
2006-01-11 02:49:16 -07:00
|
|
|
xfs_off_t offset,
|
2006-01-10 21:40:13 -07:00
|
|
|
unsigned int type,
|
|
|
|
xfs_ioend_t **result,
|
|
|
|
int need_ioend)
|
|
|
|
{
|
|
|
|
xfs_ioend_t *ioend = *result;
|
|
|
|
|
|
|
|
if (!ioend || need_ioend || type != ioend->io_type) {
|
|
|
|
xfs_ioend_t *previous = *result;
|
|
|
|
|
|
|
|
ioend = xfs_alloc_ioend(inode, type);
|
|
|
|
ioend->io_offset = offset;
|
|
|
|
ioend->io_buffer_head = bh;
|
|
|
|
ioend->io_buffer_tail = bh;
|
|
|
|
if (previous)
|
|
|
|
previous->io_list = ioend;
|
|
|
|
*result = ioend;
|
|
|
|
} else {
|
|
|
|
ioend->io_buffer_tail->b_private = bh;
|
|
|
|
ioend->io_buffer_tail = bh;
|
|
|
|
}
|
|
|
|
|
|
|
|
bh->b_private = NULL;
|
|
|
|
ioend->io_size += bh->b_size;
|
|
|
|
}
|
|
|
|
|
2006-03-13 19:26:43 -07:00
|
|
|
STATIC void
|
|
|
|
xfs_map_buffer(
|
2010-04-28 06:28:52 -06:00
|
|
|
struct inode *inode,
|
2006-03-13 19:26:43 -07:00
|
|
|
struct buffer_head *bh,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2010-04-28 06:28:52 -06:00
|
|
|
xfs_off_t offset)
|
2006-03-13 19:26:43 -07:00
|
|
|
{
|
|
|
|
sector_t bn;
|
2010-04-28 06:28:54 -06:00
|
|
|
struct xfs_mount *m = XFS_I(inode)->i_mount;
|
2010-04-28 06:28:56 -06:00
|
|
|
xfs_off_t iomap_offset = XFS_FSB_TO_B(m, imap->br_startoff);
|
|
|
|
xfs_daddr_t iomap_bn = xfs_fsb_to_db(XFS_I(inode), imap->br_startblock);
|
2006-03-13 19:26:43 -07:00
|
|
|
|
2010-04-28 06:28:56 -06:00
|
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
2006-03-13 19:26:43 -07:00
|
|
|
|
2010-04-28 06:28:55 -06:00
|
|
|
bn = (iomap_bn >> (inode->i_blkbits - BBSHIFT)) +
|
2010-04-28 06:28:54 -06:00
|
|
|
((offset - iomap_offset) >> inode->i_blkbits);
|
2006-03-13 19:26:43 -07:00
|
|
|
|
2010-04-28 06:28:52 -06:00
|
|
|
ASSERT(bn || XFS_IS_REALTIME_INODE(XFS_I(inode)));
|
2006-03-13 19:26:43 -07:00
|
|
|
|
|
|
|
bh->b_blocknr = bn;
|
|
|
|
set_buffer_mapped(bh);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
STATIC void
|
|
|
|
xfs_map_at_offset(
|
2010-04-28 06:28:52 -06:00
|
|
|
struct inode *inode,
|
2005-04-16 16:20:36 -06:00
|
|
|
struct buffer_head *bh,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2010-04-28 06:28:52 -06:00
|
|
|
xfs_off_t offset)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-04-28 06:28:56 -06:00
|
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-04-28 06:28:56 -06:00
|
|
|
xfs_map_buffer(inode, bh, imap, offset);
|
2005-04-16 16:20:36 -06:00
|
|
|
set_buffer_mapped(bh);
|
|
|
|
clear_buffer_delay(bh);
|
2006-01-10 21:40:13 -07:00
|
|
|
clear_buffer_unwritten(bh);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2006-01-11 02:48:14 -07:00
|
|
|
* Test if a given page is suitable for writing as part of an unwritten
|
|
|
|
* or delayed allocate extent.
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
2006-01-11 02:48:14 -07:00
|
|
|
STATIC int
|
2012-04-22 23:58:43 -06:00
|
|
|
xfs_check_page_type(
|
2006-01-11 02:48:14 -07:00
|
|
|
struct page *page,
|
2006-01-10 21:40:13 -07:00
|
|
|
unsigned int type)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
if (PageWriteback(page))
|
2006-01-11 02:48:14 -07:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
if (page->mapping && page_has_buffers(page)) {
|
|
|
|
struct buffer_head *bh, *head;
|
|
|
|
int acceptable = 0;
|
|
|
|
|
|
|
|
bh = head = page_buffers(page);
|
|
|
|
do {
|
2006-01-10 21:40:13 -07:00
|
|
|
if (buffer_unwritten(bh))
|
2012-04-22 23:58:43 -06:00
|
|
|
acceptable += (type == IO_UNWRITTEN);
|
2006-01-10 21:40:13 -07:00
|
|
|
else if (buffer_delay(bh))
|
2012-04-22 23:58:43 -06:00
|
|
|
acceptable += (type == IO_DELALLOC);
|
2006-03-21 18:47:40 -07:00
|
|
|
else if (buffer_dirty(bh) && buffer_mapped(bh))
|
2012-04-22 23:58:43 -06:00
|
|
|
acceptable += (type == IO_OVERWRITE);
|
2006-01-10 21:40:13 -07:00
|
|
|
else
|
2005-04-16 16:20:36 -06:00
|
|
|
break;
|
|
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
|
|
|
|
if (acceptable)
|
2006-01-11 02:48:14 -07:00
|
|
|
return 1;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2006-01-11 02:48:14 -07:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Allocate & map buffers for page given the extent map. Write it out.
|
|
|
|
* except for the original page of a writepage, this is called on
|
|
|
|
* delalloc/unwritten pages only, for the original page it is possible
|
|
|
|
* that the page has no mapping at all.
|
|
|
|
*/
|
2006-01-10 21:40:13 -07:00
|
|
|
STATIC int
|
2005-04-16 16:20:36 -06:00
|
|
|
xfs_convert_page(
|
|
|
|
struct inode *inode,
|
|
|
|
struct page *page,
|
2006-01-11 02:48:14 -07:00
|
|
|
loff_t tindex,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_ioend_t **ioendp,
|
2010-12-10 01:42:23 -07:00
|
|
|
struct writeback_control *wbc)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2006-01-10 21:40:13 -07:00
|
|
|
struct buffer_head *bh, *head;
|
2006-01-11 02:48:47 -07:00
|
|
|
xfs_off_t end_offset;
|
|
|
|
unsigned long p_offset;
|
2006-01-10 21:40:13 -07:00
|
|
|
unsigned int type;
|
2005-05-05 14:33:20 -06:00
|
|
|
int len, page_dirty;
|
2006-01-10 21:40:13 -07:00
|
|
|
int count = 0, done = 0, uptodate = 1;
|
2006-01-11 02:48:47 -07:00
|
|
|
xfs_off_t offset = page_offset(page);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2006-01-11 02:48:14 -07:00
|
|
|
if (page->index != tindex)
|
|
|
|
goto fail;
|
2008-08-02 04:01:03 -06:00
|
|
|
if (!trylock_page(page))
|
2006-01-11 02:48:14 -07:00
|
|
|
goto fail;
|
|
|
|
if (PageWriteback(page))
|
|
|
|
goto fail_unlock_page;
|
|
|
|
if (page->mapping != inode->i_mapping)
|
|
|
|
goto fail_unlock_page;
|
2012-04-22 23:58:43 -06:00
|
|
|
if (!xfs_check_page_type(page, (*ioendp)->io_type))
|
2006-01-11 02:48:14 -07:00
|
|
|
goto fail_unlock_page;
|
|
|
|
|
2005-05-05 14:33:20 -06:00
|
|
|
/*
|
|
|
|
* page_dirty is initially a count of buffers on the page before
|
2006-03-28 15:55:14 -07:00
|
|
|
* EOF and is decremented as we move each into a cleanable state.
|
2006-01-11 02:48:47 -07:00
|
|
|
*
|
|
|
|
* Derivation:
|
|
|
|
*
|
|
|
|
* End offset is the highest offset that this page should represent.
|
|
|
|
* If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
|
|
|
|
* will evaluate non-zero and be less than PAGE_CACHE_SIZE and
|
|
|
|
* hence give us the correct page_dirty count. On any other page,
|
|
|
|
* it will be zero and in that case we need page_dirty to be the
|
|
|
|
* count of buffers on the page.
|
2005-05-05 14:33:20 -06:00
|
|
|
*/
|
2006-01-11 02:48:47 -07:00
|
|
|
end_offset = min_t(unsigned long long,
|
|
|
|
(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
|
|
|
|
i_size_read(inode));
|
|
|
|
|
2005-05-05 14:33:20 -06:00
|
|
|
len = 1 << inode->i_blkbits;
|
2006-01-11 02:48:47 -07:00
|
|
|
p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
|
|
|
|
PAGE_CACHE_SIZE);
|
|
|
|
p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
|
|
|
|
page_dirty = p_offset / len;
|
2005-05-05 14:33:20 -06:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
bh = head = page_buffers(page);
|
|
|
|
do {
|
2006-01-11 02:48:47 -07:00
|
|
|
if (offset >= end_offset)
|
2005-04-16 16:20:36 -06:00
|
|
|
break;
|
2006-01-10 21:40:13 -07:00
|
|
|
if (!buffer_uptodate(bh))
|
|
|
|
uptodate = 0;
|
|
|
|
if (!(PageUptodate(page) || buffer_uptodate(bh))) {
|
|
|
|
done = 1;
|
2005-04-16 16:20:36 -06:00
|
|
|
continue;
|
2006-01-10 21:40:13 -07:00
|
|
|
}
|
|
|
|
|
2010-12-10 01:42:23 -07:00
|
|
|
if (buffer_unwritten(bh) || buffer_delay(bh) ||
|
|
|
|
buffer_mapped(bh)) {
|
2006-01-11 02:48:47 -07:00
|
|
|
if (buffer_unwritten(bh))
|
2010-04-28 06:28:57 -06:00
|
|
|
type = IO_UNWRITTEN;
|
2010-12-10 01:42:23 -07:00
|
|
|
else if (buffer_delay(bh))
|
2010-12-10 01:42:20 -07:00
|
|
|
type = IO_DELALLOC;
|
2010-12-10 01:42:23 -07:00
|
|
|
else
|
|
|
|
type = IO_OVERWRITE;
|
2006-01-11 02:48:47 -07:00
|
|
|
|
2010-04-28 06:28:58 -06:00
|
|
|
if (!xfs_imap_valid(inode, imap, offset)) {
|
2006-01-10 21:40:13 -07:00
|
|
|
done = 1;
|
2006-01-11 02:48:47 -07:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-12-10 01:42:25 -07:00
|
|
|
lock_buffer(bh);
|
|
|
|
if (type != IO_OVERWRITE)
|
2010-12-10 01:42:23 -07:00
|
|
|
xfs_map_at_offset(inode, bh, imap, offset);
|
2010-06-23 17:45:48 -06:00
|
|
|
xfs_add_to_ioend(inode, bh, offset, type,
|
|
|
|
ioendp, done);
|
|
|
|
|
2006-01-11 02:48:47 -07:00
|
|
|
page_dirty--;
|
|
|
|
count++;
|
|
|
|
} else {
|
2010-12-10 01:42:23 -07:00
|
|
|
done = 1;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2006-01-11 02:49:16 -07:00
|
|
|
} while (offset += len, (bh = bh->b_this_page) != head);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2006-01-10 21:40:13 -07:00
|
|
|
if (uptodate && bh == head)
|
|
|
|
SetPageUptodate(page);
|
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
if (count) {
|
2010-08-23 19:44:56 -06:00
|
|
|
if (--wbc->nr_to_write <= 0 &&
|
|
|
|
wbc->sync_mode == WB_SYNC_NONE)
|
2010-06-23 17:45:48 -06:00
|
|
|
done = 1;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2010-06-23 17:45:48 -06:00
|
|
|
xfs_start_page_writeback(page, !page_dirty, count);
|
2006-01-10 21:40:13 -07:00
|
|
|
|
|
|
|
return done;
|
2006-01-11 02:48:14 -07:00
|
|
|
fail_unlock_page:
|
|
|
|
unlock_page(page);
|
|
|
|
fail:
|
|
|
|
return 1;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Convert & write out a cluster of pages in the same extent as defined
|
|
|
|
* by mp and following the start page.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_cluster_write(
|
|
|
|
struct inode *inode,
|
|
|
|
pgoff_t tindex,
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec *imap,
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_ioend_t **ioendp,
|
2005-04-16 16:20:36 -06:00
|
|
|
struct writeback_control *wbc,
|
|
|
|
pgoff_t tlast)
|
|
|
|
{
|
2006-01-11 02:48:14 -07:00
|
|
|
struct pagevec pvec;
|
|
|
|
int done = 0, i;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2006-01-11 02:48:14 -07:00
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
while (!done && tindex <= tlast) {
|
|
|
|
unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
|
|
|
|
|
|
|
|
if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
|
2005-04-16 16:20:36 -06:00
|
|
|
break;
|
2006-01-11 02:48:14 -07:00
|
|
|
|
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
done = xfs_convert_page(inode, pvec.pages[i], tindex++,
|
2010-12-10 01:42:23 -07:00
|
|
|
imap, ioendp, wbc);
|
2006-01-11 02:48:14 -07:00
|
|
|
if (done)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
pagevec_release(&pvec);
|
|
|
|
cond_resched();
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-03-04 19:00:42 -07:00
|
|
|
STATIC void
|
|
|
|
xfs_vm_invalidatepage(
|
|
|
|
struct page *page,
|
|
|
|
unsigned long offset)
|
|
|
|
{
|
|
|
|
trace_xfs_invalidatepage(page->mapping->host, page, offset);
|
|
|
|
block_invalidatepage(page, offset);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If the page has delalloc buffers on it, we need to punch them out before we
|
|
|
|
* invalidate the page. If we don't, we leave a stale delalloc mapping on the
|
|
|
|
* inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
|
|
|
|
* is done on that same region - the delalloc extent is returned when none is
|
|
|
|
* supposed to be there.
|
|
|
|
*
|
|
|
|
* We prevent this by truncating away the delalloc regions on the page before
|
|
|
|
* invalidating it. Because they are delalloc, we can do this without needing a
|
|
|
|
* transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
|
|
|
|
* truncation without a transaction as there is no space left for block
|
|
|
|
* reservation (typically why we see a ENOSPC in writeback).
|
|
|
|
*
|
|
|
|
* This is not a performance critical path, so for now just do the punching a
|
|
|
|
* buffer head at a time.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_aops_discard_page(
|
|
|
|
struct page *page)
|
|
|
|
{
|
|
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
|
|
struct buffer_head *bh, *head;
|
|
|
|
loff_t offset = page_offset(page);
|
|
|
|
|
2012-04-22 23:58:43 -06:00
|
|
|
if (!xfs_check_page_type(page, IO_DELALLOC))
|
2010-03-04 19:00:42 -07:00
|
|
|
goto out_invalidate;
|
|
|
|
|
2010-03-14 20:36:35 -06:00
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
|
|
goto out_invalidate;
|
|
|
|
|
2011-03-06 16:00:35 -07:00
|
|
|
xfs_alert(ip->i_mount,
|
2010-03-04 19:00:42 -07:00
|
|
|
"page discard on page %p, inode 0x%llx, offset %llu.",
|
|
|
|
page, ip->i_ino, offset);
|
|
|
|
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
|
|
bh = head = page_buffers(page);
|
|
|
|
do {
|
|
|
|
int error;
|
2010-11-29 21:14:39 -07:00
|
|
|
xfs_fileoff_t start_fsb;
|
2010-03-04 19:00:42 -07:00
|
|
|
|
|
|
|
if (!buffer_delay(bh))
|
|
|
|
goto next_buffer;
|
|
|
|
|
2010-11-29 21:14:39 -07:00
|
|
|
start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
|
|
|
|
error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
|
2010-03-04 19:00:42 -07:00
|
|
|
if (error) {
|
|
|
|
/* something screwed, just bail */
|
2010-03-14 20:36:35 -06:00
|
|
|
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
2011-03-06 16:00:35 -07:00
|
|
|
xfs_alert(ip->i_mount,
|
2010-03-04 19:00:42 -07:00
|
|
|
"page discard unable to remove delalloc mapping.");
|
2010-03-14 20:36:35 -06:00
|
|
|
}
|
2010-03-04 19:00:42 -07:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
next_buffer:
|
2010-11-29 21:14:39 -07:00
|
|
|
offset += 1 << inode->i_blkbits;
|
2010-03-04 19:00:42 -07:00
|
|
|
|
|
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
out_invalidate:
|
|
|
|
xfs_vm_invalidatepage(page, 0);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
2010-06-23 17:45:48 -06:00
|
|
|
* Write out a dirty page.
|
|
|
|
*
|
|
|
|
* For delalloc space on the page we need to allocate space and flush it.
|
|
|
|
* For unwritten space on the page we need to start the conversion to
|
|
|
|
* regular allocated space.
|
|
|
|
* For any other dirty buffer heads on the page we should flush them.
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
|
|
|
STATIC int
|
2010-06-23 17:45:48 -06:00
|
|
|
xfs_vm_writepage(
|
|
|
|
struct page *page,
|
|
|
|
struct writeback_control *wbc)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-06-23 17:45:48 -06:00
|
|
|
struct inode *inode = page->mapping->host;
|
2006-01-10 21:40:13 -07:00
|
|
|
struct buffer_head *bh, *head;
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec imap;
|
2006-01-10 21:40:13 -07:00
|
|
|
xfs_ioend_t *ioend = NULL, *iohead = NULL;
|
2005-04-16 16:20:36 -06:00
|
|
|
loff_t offset;
|
2006-01-10 21:40:13 -07:00
|
|
|
unsigned int type;
|
2005-04-16 16:20:36 -06:00
|
|
|
__uint64_t end_offset;
|
2010-04-28 06:29:00 -06:00
|
|
|
pgoff_t end_index, last_index;
|
2010-12-10 01:42:22 -07:00
|
|
|
ssize_t len;
|
2010-12-10 01:42:20 -07:00
|
|
|
int err, imap_valid = 0, uptodate = 1;
|
2010-06-23 17:45:48 -06:00
|
|
|
int count = 0;
|
2010-12-10 01:42:20 -07:00
|
|
|
int nonblocking = 0;
|
2010-06-23 17:45:48 -06:00
|
|
|
|
|
|
|
trace_xfs_writepage(inode, page, 0);
|
|
|
|
|
2010-06-23 17:46:01 -06:00
|
|
|
ASSERT(page_has_buffers(page));
|
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
/*
|
|
|
|
* Refuse to write the page out if we are called from reclaim context.
|
|
|
|
*
|
2010-06-28 08:34:44 -06:00
|
|
|
* This avoids stack overflows when called from deeply used stacks in
|
|
|
|
* random callers for direct reclaim or memcg reclaim. We explicitly
|
|
|
|
* allow reclaim from kswapd as the stack usage there is relatively low.
|
2010-06-23 17:45:48 -06:00
|
|
|
*
|
2011-10-31 18:07:45 -06:00
|
|
|
* This should never happen except in the case of a VM regression so
|
|
|
|
* warn about it.
|
2010-06-23 17:45:48 -06:00
|
|
|
*/
|
2011-10-31 18:07:45 -06:00
|
|
|
if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
|
|
|
|
PF_MEMALLOC))
|
2010-08-23 19:47:51 -06:00
|
|
|
goto redirty;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
/*
|
2011-07-08 06:34:05 -06:00
|
|
|
* Given that we do not allow direct reclaim to call us, we should
|
|
|
|
* never be called while in a filesystem transaction.
|
2010-06-23 17:45:48 -06:00
|
|
|
*/
|
2011-07-08 06:34:05 -06:00
|
|
|
if (WARN_ON(current->flags & PF_FSTRANS))
|
2010-08-23 19:47:51 -06:00
|
|
|
goto redirty;
|
2010-06-23 17:45:48 -06:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/* Is this page beyond the end of the file? */
|
|
|
|
offset = i_size_read(inode);
|
|
|
|
end_index = offset >> PAGE_CACHE_SHIFT;
|
|
|
|
last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
|
|
|
|
if (page->index >= end_index) {
|
|
|
|
if ((page->index >= end_index + 1) ||
|
|
|
|
!(i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
|
2010-06-23 17:45:48 -06:00
|
|
|
unlock_page(page);
|
2005-11-01 21:14:09 -07:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2006-01-10 21:40:13 -07:00
|
|
|
end_offset = min_t(unsigned long long,
|
2010-06-23 17:46:01 -06:00
|
|
|
(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
|
|
|
|
offset);
|
2005-05-05 14:33:20 -06:00
|
|
|
len = 1 << inode->i_blkbits;
|
|
|
|
|
|
|
|
bh = head = page_buffers(page);
|
2006-01-10 21:40:13 -07:00
|
|
|
offset = page_offset(page);
|
2010-12-10 01:42:20 -07:00
|
|
|
type = IO_OVERWRITE;
|
|
|
|
|
2011-07-08 06:34:14 -06:00
|
|
|
if (wbc->sync_mode == WB_SYNC_NONE)
|
2010-12-10 01:42:20 -07:00
|
|
|
nonblocking = 1;
|
2006-01-10 21:40:13 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
do {
|
2010-12-10 01:42:18 -07:00
|
|
|
int new_ioend = 0;
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
if (offset >= end_offset)
|
|
|
|
break;
|
|
|
|
if (!buffer_uptodate(bh))
|
|
|
|
uptodate = 0;
|
|
|
|
|
2010-06-23 17:45:30 -06:00
|
|
|
/*
|
2010-11-10 14:39:11 -07:00
|
|
|
* set_page_dirty dirties all buffers in a page, independent
|
|
|
|
* of their state. The dirty state however is entirely
|
|
|
|
* meaningless for holes (!mapped && uptodate), so skip
|
|
|
|
* buffers covering holes here.
|
2010-06-23 17:45:30 -06:00
|
|
|
*/
|
|
|
|
if (!buffer_mapped(bh) && buffer_uptodate(bh)) {
|
|
|
|
imap_valid = 0;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-12-10 01:42:24 -07:00
|
|
|
if (buffer_unwritten(bh)) {
|
|
|
|
if (type != IO_UNWRITTEN) {
|
|
|
|
type = IO_UNWRITTEN;
|
|
|
|
imap_valid = 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2010-12-10 01:42:24 -07:00
|
|
|
} else if (buffer_delay(bh)) {
|
|
|
|
if (type != IO_DELALLOC) {
|
|
|
|
type = IO_DELALLOC;
|
|
|
|
imap_valid = 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2010-06-23 17:45:48 -06:00
|
|
|
} else if (buffer_uptodate(bh)) {
|
2010-12-10 01:42:20 -07:00
|
|
|
if (type != IO_OVERWRITE) {
|
|
|
|
type = IO_OVERWRITE;
|
2010-12-10 01:42:16 -07:00
|
|
|
imap_valid = 0;
|
|
|
|
}
|
2010-12-10 01:42:24 -07:00
|
|
|
} else {
|
|
|
|
if (PageUptodate(page)) {
|
|
|
|
ASSERT(buffer_mapped(bh));
|
|
|
|
imap_valid = 0;
|
2006-01-11 02:49:28 -07:00
|
|
|
}
|
2010-12-10 01:42:24 -07:00
|
|
|
continue;
|
|
|
|
}
|
2006-01-11 02:49:02 -07:00
|
|
|
|
2010-12-10 01:42:24 -07:00
|
|
|
if (imap_valid)
|
|
|
|
imap_valid = xfs_imap_valid(inode, &imap, offset);
|
|
|
|
if (!imap_valid) {
|
|
|
|
/*
|
|
|
|
* If we didn't have a valid mapping then we need to
|
|
|
|
* put the new mapping into a separate ioend structure.
|
|
|
|
* This ensures non-contiguous extents always have
|
|
|
|
* separate ioends, which is particularly important
|
|
|
|
* for unwritten extent conversion at I/O completion
|
|
|
|
* time.
|
|
|
|
*/
|
|
|
|
new_ioend = 1;
|
|
|
|
err = xfs_map_blocks(inode, offset, &imap, type,
|
|
|
|
nonblocking);
|
|
|
|
if (err)
|
|
|
|
goto error;
|
|
|
|
imap_valid = xfs_imap_valid(inode, &imap, offset);
|
|
|
|
}
|
|
|
|
if (imap_valid) {
|
2010-12-10 01:42:25 -07:00
|
|
|
lock_buffer(bh);
|
|
|
|
if (type != IO_OVERWRITE)
|
2010-12-10 01:42:24 -07:00
|
|
|
xfs_map_at_offset(inode, bh, &imap, offset);
|
|
|
|
xfs_add_to_ioend(inode, bh, offset, type, &ioend,
|
|
|
|
new_ioend);
|
|
|
|
count++;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2006-01-10 21:40:13 -07:00
|
|
|
|
|
|
|
if (!iohead)
|
|
|
|
iohead = ioend;
|
|
|
|
|
|
|
|
} while (offset += len, ((bh = bh->b_this_page) != head));
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
if (uptodate && bh == head)
|
|
|
|
SetPageUptodate(page);
|
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
xfs_start_page_writeback(page, 1, count);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-04-28 06:28:58 -06:00
|
|
|
if (ioend && imap_valid) {
|
2010-04-28 06:29:00 -06:00
|
|
|
xfs_off_t end_index;
|
|
|
|
|
|
|
|
end_index = imap.br_startoff + imap.br_blockcount;
|
|
|
|
|
|
|
|
/* to bytes */
|
|
|
|
end_index <<= inode->i_blkbits;
|
|
|
|
|
|
|
|
/* to pages */
|
|
|
|
end_index = (end_index - 1) >> PAGE_CACHE_SHIFT;
|
|
|
|
|
|
|
|
/* check against file size */
|
|
|
|
if (end_index > last_index)
|
|
|
|
end_index = last_index;
|
2010-04-28 06:28:54 -06:00
|
|
|
|
2010-04-28 06:28:56 -06:00
|
|
|
xfs_cluster_write(inode, page->index + 1, &imap, &ioend,
|
2010-12-10 01:42:23 -07:00
|
|
|
wbc, end_index);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2012-03-13 02:41:05 -06:00
|
|
|
if (iohead) {
|
|
|
|
/*
|
|
|
|
* Reserve log space if we might write beyond the on-disk
|
|
|
|
* inode size.
|
|
|
|
*/
|
|
|
|
if (ioend->io_type != IO_UNWRITTEN &&
|
|
|
|
xfs_ioend_is_append(ioend)) {
|
|
|
|
err = xfs_setfilesize_trans_alloc(ioend);
|
|
|
|
if (err)
|
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
2009-10-30 03:09:15 -06:00
|
|
|
xfs_submit_ioend(wbc, iohead);
|
2012-03-13 02:41:05 -06:00
|
|
|
}
|
2006-01-10 21:40:13 -07:00
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
error:
|
2006-01-10 21:40:13 -07:00
|
|
|
if (iohead)
|
|
|
|
xfs_cancel_ioend(iohead);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-08-23 19:47:51 -06:00
|
|
|
if (err == -EAGAIN)
|
|
|
|
goto redirty;
|
|
|
|
|
2010-06-23 17:46:01 -06:00
|
|
|
xfs_aops_discard_page(page);
|
2010-06-23 17:45:48 -06:00
|
|
|
ClearPageUptodate(page);
|
|
|
|
unlock_page(page);
|
2005-04-16 16:20:36 -06:00
|
|
|
return err;
|
2006-03-13 19:26:27 -07:00
|
|
|
|
2010-08-23 19:47:51 -06:00
|
|
|
redirty:
|
2006-03-13 19:26:27 -07:00
|
|
|
redirty_page_for_writepage(wbc, page);
|
|
|
|
unlock_page(page);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2006-06-08 23:27:16 -06:00
|
|
|
STATIC int
|
|
|
|
xfs_vm_writepages(
|
|
|
|
struct address_space *mapping,
|
|
|
|
struct writeback_control *wbc)
|
|
|
|
{
|
2007-08-28 19:44:37 -06:00
|
|
|
xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
|
2006-06-08 23:27:16 -06:00
|
|
|
return generic_writepages(mapping, wbc);
|
|
|
|
}
|
|
|
|
|
2006-03-13 19:26:27 -07:00
|
|
|
/*
|
|
|
|
* Called to move a page into cleanable state - and from there
|
2010-06-23 17:45:48 -06:00
|
|
|
* to be released. The page should already be clean. We always
|
2006-03-13 19:26:27 -07:00
|
|
|
* have buffer heads in this call.
|
|
|
|
*
|
2010-06-23 17:45:48 -06:00
|
|
|
* Returns 1 if the page is ok to release, 0 otherwise.
|
2006-03-13 19:26:27 -07:00
|
|
|
*/
|
|
|
|
STATIC int
|
2006-03-16 23:26:25 -07:00
|
|
|
xfs_vm_releasepage(
|
2006-03-13 19:26:27 -07:00
|
|
|
struct page *page,
|
|
|
|
gfp_t gfp_mask)
|
|
|
|
{
|
2010-06-23 17:46:01 -06:00
|
|
|
int delalloc, unwritten;
|
2006-03-13 19:26:27 -07:00
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
trace_xfs_releasepage(page->mapping->host, page, 0);
|
2006-03-16 23:26:25 -07:00
|
|
|
|
2010-06-23 17:46:01 -06:00
|
|
|
xfs_count_page_state(page, &delalloc, &unwritten);
|
2006-03-13 19:26:27 -07:00
|
|
|
|
2010-06-23 17:45:48 -06:00
|
|
|
if (WARN_ON(delalloc))
|
2006-03-13 19:26:27 -07:00
|
|
|
return 0;
|
2010-06-23 17:45:48 -06:00
|
|
|
if (WARN_ON(unwritten))
|
2006-03-13 19:26:27 -07:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
return try_to_free_buffers(page);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
STATIC int
|
2006-03-28 17:44:40 -07:00
|
|
|
__xfs_get_blocks(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct inode *inode,
|
|
|
|
sector_t iblock,
|
|
|
|
struct buffer_head *bh_result,
|
|
|
|
int create,
|
2010-06-23 19:44:35 -06:00
|
|
|
int direct)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-12-10 01:42:20 -07:00
|
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
|
|
xfs_fileoff_t offset_fsb, end_fsb;
|
|
|
|
int error = 0;
|
|
|
|
int lockmode = 0;
|
2010-04-28 06:28:56 -06:00
|
|
|
struct xfs_bmbt_irec imap;
|
2010-12-10 01:42:20 -07:00
|
|
|
int nimaps = 1;
|
2005-11-01 21:13:13 -07:00
|
|
|
xfs_off_t offset;
|
|
|
|
ssize_t size;
|
2010-04-28 06:28:56 -06:00
|
|
|
int new = 0;
|
2010-12-10 01:42:20 -07:00
|
|
|
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
|
|
return -XFS_ERROR(EIO);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2005-11-01 21:13:13 -07:00
|
|
|
offset = (xfs_off_t)iblock << inode->i_blkbits;
|
2006-03-28 17:44:40 -07:00
|
|
|
ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
|
|
|
|
size = bh_result->b_size;
|
2008-09-17 00:50:14 -06:00
|
|
|
|
|
|
|
if (!create && direct && offset >= i_size_read(inode))
|
|
|
|
return 0;
|
|
|
|
|
2012-03-27 08:34:50 -06:00
|
|
|
/*
|
|
|
|
* Direct I/O is usually done on preallocated files, so try getting
|
|
|
|
* a block mapping without an exclusive lock first. For buffered
|
|
|
|
* writes we already have the exclusive iolock anyway, so avoiding
|
|
|
|
* a lock roundtrip here by taking the ilock exclusive from the
|
|
|
|
* beginning is a useful micro optimization.
|
|
|
|
*/
|
|
|
|
if (create && !direct) {
|
2010-12-10 01:42:20 -07:00
|
|
|
lockmode = XFS_ILOCK_EXCL;
|
|
|
|
xfs_ilock(ip, lockmode);
|
|
|
|
} else {
|
|
|
|
lockmode = xfs_ilock_map_shared(ip);
|
|
|
|
}
|
2010-06-23 19:44:35 -06:00
|
|
|
|
2010-12-10 01:42:20 -07:00
|
|
|
ASSERT(offset <= mp->m_maxioffset);
|
|
|
|
if (offset + size > mp->m_maxioffset)
|
|
|
|
size = mp->m_maxioffset - offset;
|
|
|
|
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
|
|
|
|
offset_fsb = XFS_B_TO_FSBT(mp, offset);
|
|
|
|
|
2011-09-18 14:40:45 -06:00
|
|
|
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
|
|
|
|
&imap, &nimaps, XFS_BMAPI_ENTIRE);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (error)
|
2010-12-10 01:42:20 -07:00
|
|
|
goto out_unlock;
|
|
|
|
|
|
|
|
if (create &&
|
|
|
|
(!nimaps ||
|
|
|
|
(imap.br_startblock == HOLESTARTBLOCK ||
|
|
|
|
imap.br_startblock == DELAYSTARTBLOCK))) {
|
xfs: Use preallocation for inodes with extsz hints
xfstest 229 exposes a problem with buffered IO, delayed allocation
and extent size hints. That is when we do delayed allocation during
buffered IO, we reserve space for the extent size hint alignment and
allocate the physical space to align the extent, but we do not zero
the regions of the extent that aren't written by the write(2)
syscall. The result is that we expose stale data in unwritten
regions of the extent size hints.
There are two ways to fix this. The first is to detect that we are
doing unaligned writes, check if there is already a mapping or data
over the extent size hint range, and if not zero the page cache
first before then doing the real write. This can be very expensive
for large extent size hints, especially if the subsequent writes
fill then entire extent size before the data is written to disk.
The second, and simpler way, is simply to turn off delayed
allocation when the extent size hint is set and use preallocation
instead. This results in unwritten extents being laid down on disk
and so only the written portions will be converted. This matches the
behaviour for direct IO, and will also work for the real time
device. The disadvantage of this approach is that for small extent
size hints we can get file fragmentation, but in general extent size
hints are fairly large (e.g. stripe width sized) so this isn't a big
deal.
Implement the second approach as it is simple and effective.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-22 23:58:44 -06:00
|
|
|
if (direct || xfs_get_extsz_hint(ip)) {
|
2012-03-27 08:34:50 -06:00
|
|
|
/*
|
|
|
|
* Drop the ilock in preparation for starting the block
|
|
|
|
* allocation transaction. It will be retaken
|
|
|
|
* exclusively inside xfs_iomap_write_direct for the
|
|
|
|
* actual allocation.
|
|
|
|
*/
|
|
|
|
xfs_iunlock(ip, lockmode);
|
2010-12-10 01:42:20 -07:00
|
|
|
error = xfs_iomap_write_direct(ip, offset, size,
|
|
|
|
&imap, nimaps);
|
2012-03-27 08:34:50 -06:00
|
|
|
if (error)
|
|
|
|
return -error;
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
new = 1;
|
2010-12-10 01:42:20 -07:00
|
|
|
} else {
|
2012-03-27 08:34:50 -06:00
|
|
|
/*
|
|
|
|
* Delalloc reservations do not require a transaction,
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
* we can go on without dropping the lock here. If we
|
|
|
|
* are allocating a new delalloc block, make sure that
|
|
|
|
* we set the new flag so that we mark the buffer new so
|
|
|
|
* that we know that it is newly allocated if the write
|
|
|
|
* fails.
|
2012-03-27 08:34:50 -06:00
|
|
|
*/
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
|
|
|
|
new = 1;
|
2010-12-10 01:42:20 -07:00
|
|
|
error = xfs_iomap_write_delay(ip, offset, size, &imap);
|
2012-03-27 08:34:50 -06:00
|
|
|
if (error)
|
|
|
|
goto out_unlock;
|
|
|
|
|
|
|
|
xfs_iunlock(ip, lockmode);
|
2010-12-10 01:42:20 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
trace_xfs_get_blocks_alloc(ip, offset, size, 0, &imap);
|
|
|
|
} else if (nimaps) {
|
|
|
|
trace_xfs_get_blocks_found(ip, offset, size, 0, &imap);
|
2012-03-27 08:34:50 -06:00
|
|
|
xfs_iunlock(ip, lockmode);
|
2010-12-10 01:42:20 -07:00
|
|
|
} else {
|
|
|
|
trace_xfs_get_blocks_notfound(ip, offset, size);
|
|
|
|
goto out_unlock;
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-04-28 06:28:56 -06:00
|
|
|
if (imap.br_startblock != HOLESTARTBLOCK &&
|
|
|
|
imap.br_startblock != DELAYSTARTBLOCK) {
|
2006-03-13 19:26:43 -07:00
|
|
|
/*
|
|
|
|
* For unwritten extents do not report a disk address on
|
2005-04-16 16:20:36 -06:00
|
|
|
* the read case (treat as if we're reading into a hole).
|
|
|
|
*/
|
2010-04-28 06:28:56 -06:00
|
|
|
if (create || !ISUNWRITTEN(&imap))
|
|
|
|
xfs_map_buffer(inode, bh_result, &imap, offset);
|
|
|
|
if (create && ISUNWRITTEN(&imap)) {
|
2005-04-16 16:20:36 -06:00
|
|
|
if (direct)
|
|
|
|
bh_result->b_private = inode;
|
|
|
|
set_buffer_unwritten(bh_result);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2006-03-28 17:44:40 -07:00
|
|
|
/*
|
|
|
|
* If this is a realtime file, data may be on a different device.
|
|
|
|
* to that pointed to from the buffer_head b_bdev currently.
|
|
|
|
*/
|
2010-04-28 06:28:52 -06:00
|
|
|
bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2006-03-28 17:44:40 -07:00
|
|
|
/*
|
2007-02-10 00:36:35 -07:00
|
|
|
* If we previously allocated a block out beyond eof and we are now
|
|
|
|
* coming back to use it then we will need to flag it as new even if it
|
|
|
|
* has a disk address.
|
|
|
|
*
|
|
|
|
* With sub-block writes into unwritten extents we also need to mark
|
|
|
|
* the buffer as new so that the unwritten parts of the buffer gets
|
|
|
|
* correctly zeroed.
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
|
|
|
if (create &&
|
|
|
|
((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
|
2007-02-10 00:36:35 -07:00
|
|
|
(offset >= i_size_read(inode)) ||
|
2010-04-28 06:28:56 -06:00
|
|
|
(new || ISUNWRITTEN(&imap))))
|
2005-04-16 16:20:36 -06:00
|
|
|
set_buffer_new(bh_result);
|
|
|
|
|
2010-04-28 06:28:56 -06:00
|
|
|
if (imap.br_startblock == DELAYSTARTBLOCK) {
|
2005-04-16 16:20:36 -06:00
|
|
|
BUG_ON(direct);
|
|
|
|
if (create) {
|
|
|
|
set_buffer_uptodate(bh_result);
|
|
|
|
set_buffer_mapped(bh_result);
|
|
|
|
set_buffer_delay(bh_result);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-04-28 06:28:59 -06:00
|
|
|
/*
|
|
|
|
* If this is O_DIRECT or the mpage code calling tell them how large
|
|
|
|
* the mapping is, so that we can avoid repeated get_blocks calls.
|
|
|
|
*/
|
2006-03-28 17:44:40 -07:00
|
|
|
if (direct || size > (1 << inode->i_blkbits)) {
|
2010-04-28 06:28:59 -06:00
|
|
|
xfs_off_t mapping_size;
|
|
|
|
|
|
|
|
mapping_size = imap.br_startoff + imap.br_blockcount - iblock;
|
|
|
|
mapping_size <<= inode->i_blkbits;
|
|
|
|
|
|
|
|
ASSERT(mapping_size > 0);
|
|
|
|
if (mapping_size > size)
|
|
|
|
mapping_size = size;
|
|
|
|
if (mapping_size > LONG_MAX)
|
|
|
|
mapping_size = LONG_MAX;
|
|
|
|
|
|
|
|
bh_result->b_size = mapping_size;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
2010-12-10 01:42:20 -07:00
|
|
|
|
|
|
|
out_unlock:
|
|
|
|
xfs_iunlock(ip, lockmode);
|
|
|
|
return -error;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
int
|
2006-03-28 17:44:40 -07:00
|
|
|
xfs_get_blocks(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct inode *inode,
|
|
|
|
sector_t iblock,
|
|
|
|
struct buffer_head *bh_result,
|
|
|
|
int create)
|
|
|
|
{
|
2010-06-23 19:44:35 -06:00
|
|
|
return __xfs_get_blocks(inode, iblock, bh_result, create, 0);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
STATIC int
|
2006-03-13 19:54:26 -07:00
|
|
|
xfs_get_blocks_direct(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct inode *inode,
|
|
|
|
sector_t iblock,
|
|
|
|
struct buffer_head *bh_result,
|
|
|
|
int create)
|
|
|
|
{
|
2010-06-23 19:44:35 -06:00
|
|
|
return __xfs_get_blocks(inode, iblock, bh_result, create, 1);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2010-07-18 15:17:11 -06:00
|
|
|
/*
|
|
|
|
* Complete a direct I/O write request.
|
|
|
|
*
|
|
|
|
* If the private argument is non-NULL __xfs_get_blocks signals us that we
|
|
|
|
* need to issue a transaction to convert the range from unwritten to written
|
|
|
|
* extents. In case this is regular synchronous I/O we just call xfs_end_io
|
2011-03-30 19:57:33 -06:00
|
|
|
* to do this and we are done. But in case this was a successful AIO
|
2010-07-18 15:17:11 -06:00
|
|
|
* request this handler is called from interrupt context, from which we
|
|
|
|
* can't start transactions. In that case offload the I/O completion to
|
|
|
|
* the workqueues we also use for buffered I/O completion.
|
|
|
|
*/
|
2005-09-04 16:22:52 -06:00
|
|
|
STATIC void
|
2010-07-18 15:17:11 -06:00
|
|
|
xfs_end_io_direct_write(
|
|
|
|
struct kiocb *iocb,
|
|
|
|
loff_t offset,
|
|
|
|
ssize_t size,
|
|
|
|
void *private,
|
|
|
|
int ret,
|
|
|
|
bool is_async)
|
2005-09-04 16:22:52 -06:00
|
|
|
{
|
2010-07-18 15:17:11 -06:00
|
|
|
struct xfs_ioend *ioend = iocb->private;
|
2005-09-04 16:22:52 -06:00
|
|
|
|
2011-12-18 13:00:12 -07:00
|
|
|
/*
|
|
|
|
* While the generic direct I/O code updates the inode size, it does
|
|
|
|
* so only after the end_io handler is called, which means our
|
|
|
|
* end_io handler thinks the on-disk size is outside the in-core
|
|
|
|
* size. To prevent this just update it a little bit earlier here.
|
|
|
|
*/
|
|
|
|
if (offset + size > i_size_read(ioend->io_inode))
|
|
|
|
i_size_write(ioend->io_inode, offset + size);
|
|
|
|
|
2005-09-04 16:22:52 -06:00
|
|
|
/*
|
2010-07-18 15:17:11 -06:00
|
|
|
* blockdev_direct_IO can return an error even after the I/O
|
|
|
|
* completion handler was called. Thus we need to protect
|
|
|
|
* against double-freeing.
|
2005-09-04 16:22:52 -06:00
|
|
|
*/
|
2010-07-18 15:17:11 -06:00
|
|
|
iocb->private = NULL;
|
|
|
|
|
[XFS] Fix to prevent the notorious 'NULL files' problem after a crash.
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-07 21:49:46 -06:00
|
|
|
ioend->io_offset = offset;
|
|
|
|
ioend->io_size = size;
|
2011-08-23 02:28:10 -06:00
|
|
|
ioend->io_iocb = iocb;
|
|
|
|
ioend->io_result = ret;
|
2010-07-18 15:17:11 -06:00
|
|
|
if (private && size > 0)
|
|
|
|
ioend->io_type = IO_UNWRITTEN;
|
|
|
|
|
|
|
|
if (is_async) {
|
2011-08-23 02:28:10 -06:00
|
|
|
ioend->io_isasync = 1;
|
2010-07-18 15:17:11 -06:00
|
|
|
xfs_finish_ioend(ioend);
|
2005-09-04 16:22:52 -06:00
|
|
|
} else {
|
2010-07-18 15:17:11 -06:00
|
|
|
xfs_finish_ioend_sync(ioend);
|
2005-09-04 16:22:52 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
STATIC ssize_t
|
2006-03-13 19:54:26 -07:00
|
|
|
xfs_vm_direct_IO(
|
2005-04-16 16:20:36 -06:00
|
|
|
int rw,
|
|
|
|
struct kiocb *iocb,
|
|
|
|
const struct iovec *iov,
|
|
|
|
loff_t offset,
|
|
|
|
unsigned long nr_segs)
|
|
|
|
{
|
2010-07-18 15:17:11 -06:00
|
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
|
|
struct block_device *bdev = xfs_find_bdev_for_inode(inode);
|
2012-03-13 02:41:05 -06:00
|
|
|
struct xfs_ioend *ioend = NULL;
|
2010-07-18 15:17:11 -06:00
|
|
|
ssize_t ret;
|
|
|
|
|
|
|
|
if (rw & WRITE) {
|
2012-03-13 02:41:05 -06:00
|
|
|
size_t size = iov_length(iov, nr_segs);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We need to preallocate a transaction for a size update
|
|
|
|
* here. In the case that this write both updates the size
|
|
|
|
* and converts at least on unwritten extent we will cancel
|
|
|
|
* the still clean transaction after the I/O has finished.
|
|
|
|
*/
|
|
|
|
iocb->private = ioend = xfs_alloc_ioend(inode, IO_DIRECT);
|
|
|
|
if (offset + size > XFS_I(inode)->i_d.di_size) {
|
|
|
|
ret = xfs_setfilesize_trans_alloc(ioend);
|
|
|
|
if (ret)
|
|
|
|
goto out_destroy_ioend;
|
|
|
|
ioend->io_isdirect = 1;
|
|
|
|
}
|
2010-07-18 15:17:11 -06:00
|
|
|
|
2010-06-04 03:29:53 -06:00
|
|
|
ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
|
|
|
|
offset, nr_segs,
|
|
|
|
xfs_get_blocks_direct,
|
|
|
|
xfs_end_io_direct_write, NULL, 0);
|
2010-07-18 15:17:11 -06:00
|
|
|
if (ret != -EIOCBQUEUED && iocb->private)
|
2012-03-13 02:41:05 -06:00
|
|
|
goto out_trans_cancel;
|
2010-07-18 15:17:11 -06:00
|
|
|
} else {
|
2010-06-04 03:29:53 -06:00
|
|
|
ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
|
|
|
|
offset, nr_segs,
|
|
|
|
xfs_get_blocks_direct,
|
|
|
|
NULL, NULL, 0);
|
2010-07-18 15:17:11 -06:00
|
|
|
}
|
2005-09-04 16:22:52 -06:00
|
|
|
|
|
|
|
return ret;
|
2012-03-13 02:41:05 -06:00
|
|
|
|
|
|
|
out_trans_cancel:
|
|
|
|
if (ioend->io_append_trans) {
|
|
|
|
current_set_flags_nested(&ioend->io_append_trans->t_pflags,
|
|
|
|
PF_FSTRANS);
|
|
|
|
xfs_trans_cancel(ioend->io_append_trans, 0);
|
|
|
|
}
|
|
|
|
out_destroy_ioend:
|
|
|
|
xfs_destroy_ioend(ioend);
|
|
|
|
return ret;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
/*
|
|
|
|
* Punch out the delalloc blocks we have already allocated.
|
|
|
|
*
|
|
|
|
* Don't bother with xfs_setattr given that nothing can have made it to disk yet
|
|
|
|
* as the page is still locked at this point.
|
|
|
|
*/
|
|
|
|
STATIC void
|
|
|
|
xfs_vm_kill_delalloc_range(
|
|
|
|
struct inode *inode,
|
|
|
|
loff_t start,
|
|
|
|
loff_t end)
|
|
|
|
{
|
|
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
|
|
xfs_fileoff_t start_fsb;
|
|
|
|
xfs_fileoff_t end_fsb;
|
|
|
|
int error;
|
|
|
|
|
|
|
|
start_fsb = XFS_B_TO_FSB(ip->i_mount, start);
|
|
|
|
end_fsb = XFS_B_TO_FSB(ip->i_mount, end);
|
|
|
|
if (end_fsb <= start_fsb)
|
|
|
|
return;
|
|
|
|
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
|
|
error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
|
|
|
|
end_fsb - start_fsb);
|
|
|
|
if (error) {
|
|
|
|
/* something screwed, just bail */
|
|
|
|
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
|
|
xfs_alert(ip->i_mount,
|
|
|
|
"xfs_vm_write_failed: unable to clean up ino %lld",
|
|
|
|
ip->i_ino);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
}
|
|
|
|
|
2010-06-14 03:17:31 -06:00
|
|
|
STATIC void
|
|
|
|
xfs_vm_write_failed(
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
struct inode *inode,
|
|
|
|
struct page *page,
|
|
|
|
loff_t pos,
|
|
|
|
unsigned len)
|
2010-06-14 03:17:31 -06:00
|
|
|
{
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
loff_t block_offset = pos & PAGE_MASK;
|
|
|
|
loff_t block_start;
|
|
|
|
loff_t block_end;
|
|
|
|
loff_t from = pos & (PAGE_CACHE_SIZE - 1);
|
|
|
|
loff_t to = from + len;
|
|
|
|
struct buffer_head *bh, *head;
|
2010-06-14 03:17:31 -06:00
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
ASSERT(block_offset + from == pos);
|
2010-11-29 21:14:39 -07:00
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
head = page_buffers(page);
|
|
|
|
block_start = 0;
|
|
|
|
for (bh = head; bh != head || !block_start;
|
|
|
|
bh = bh->b_this_page, block_start = block_end,
|
|
|
|
block_offset += bh->b_size) {
|
|
|
|
block_end = block_start + bh->b_size;
|
2010-11-29 21:14:39 -07:00
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
/* skip buffers before the write */
|
|
|
|
if (block_end <= from)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/* if the buffer is after the write, we're done */
|
|
|
|
if (block_start >= to)
|
|
|
|
break;
|
|
|
|
|
|
|
|
if (!buffer_delay(bh))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (!buffer_new(bh) && block_offset < i_size_read(inode))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
xfs_vm_kill_delalloc_range(inode, block_offset,
|
|
|
|
block_offset + bh->b_size);
|
2010-06-14 03:17:31 -06:00
|
|
|
}
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
|
2010-06-14 03:17:31 -06:00
|
|
|
}
|
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
/*
|
|
|
|
* This used to call block_write_begin(), but it unlocks and releases the page
|
|
|
|
* on error, and we need that page to be able to punch stale delalloc blocks out
|
|
|
|
* on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at
|
|
|
|
* the appropriate point.
|
|
|
|
*/
|
2006-03-13 19:26:27 -07:00
|
|
|
STATIC int
|
2007-10-16 02:25:06 -06:00
|
|
|
xfs_vm_write_begin(
|
2006-03-13 19:26:27 -07:00
|
|
|
struct file *file,
|
2007-10-16 02:25:06 -06:00
|
|
|
struct address_space *mapping,
|
|
|
|
loff_t pos,
|
|
|
|
unsigned len,
|
|
|
|
unsigned flags,
|
|
|
|
struct page **pagep,
|
|
|
|
void **fsdata)
|
2006-03-13 19:26:27 -07:00
|
|
|
{
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
|
|
|
|
struct page *page;
|
|
|
|
int status;
|
2010-06-04 03:29:58 -06:00
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
ASSERT(len <= PAGE_CACHE_SIZE);
|
|
|
|
|
|
|
|
page = grab_cache_page_write_begin(mapping, index,
|
|
|
|
flags | AOP_FLAG_NOFS);
|
|
|
|
if (!page)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
status = __block_write_begin(page, pos, len, xfs_get_blocks);
|
|
|
|
if (unlikely(status)) {
|
|
|
|
struct inode *inode = mapping->host;
|
|
|
|
|
|
|
|
xfs_vm_write_failed(inode, page, pos, len);
|
|
|
|
unlock_page(page);
|
|
|
|
|
|
|
|
if (pos + len > i_size_read(inode))
|
|
|
|
truncate_pagecache(inode, pos + len, i_size_read(inode));
|
|
|
|
|
|
|
|
page_cache_release(page);
|
|
|
|
page = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
*pagep = page;
|
|
|
|
return status;
|
2010-06-14 03:17:31 -06:00
|
|
|
}
|
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
/*
|
|
|
|
* On failure, we only need to kill delalloc blocks beyond EOF because they
|
|
|
|
* will never be written. For blocks within EOF, generic_write_end() zeros them
|
|
|
|
* so they are safe to leave alone and be written with all the other valid data.
|
|
|
|
*/
|
2010-06-14 03:17:31 -06:00
|
|
|
STATIC int
|
|
|
|
xfs_vm_write_end(
|
|
|
|
struct file *file,
|
|
|
|
struct address_space *mapping,
|
|
|
|
loff_t pos,
|
|
|
|
unsigned len,
|
|
|
|
unsigned copied,
|
|
|
|
struct page *page,
|
|
|
|
void *fsdata)
|
|
|
|
{
|
|
|
|
int ret;
|
2010-06-04 03:29:58 -06:00
|
|
|
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
ASSERT(len <= PAGE_CACHE_SIZE);
|
|
|
|
|
2010-06-14 03:17:31 -06:00
|
|
|
ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
|
xfs: punch new delalloc blocks out of failed writes inside EOF.
When a partial write inside EOF fails, it can leave delayed
allocation blocks lying around because they don't get punched back
out. This leads to assert failures like:
XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847
when evicting inodes from the cache. This can be trivially triggered
by xfstests 083, which takes between 5 and 15 executions on a 512
byte block size filesystem to trip over this. Debugging shows a
failed write due to ENOSPC calling xfs_vm_write_failed such as:
[ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae
and no action is taken on it. This leaves behind a delayed
allocation extent that has no page covering it and no data in it:
[ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0
[ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1
[ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b
[ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1
^^^^^^^^^^^^^^^
[ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd
[ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa
So the delayed allocation extent is one block long at offset
0x16c00. Tracing shows that a bigger write:
xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags
allocates the block, and then fails with ENOSPC trying to allocate
the last block on the page, leading to a failed write with stale
delalloc blocks on it.
Because we've had an ENOSPC when trying to allocate 0x16e00, it
means that we are never goinge to call ->write_end on the page and
so the allocated new buffer will not get marked dirty or have the
buffer_new state cleared. In other works, what the above write is
supposed to end up with is this mapping for the page:
+------+------+------+------+------+------+------+------+
UMA UMA UMA UMA UMA UMA UND FAIL
where: U = uptodate
M = mapped
N = new
A = allocated
D = delalloc
FAIL = block we ENOSPC'd on.
and the key point being the buffer_new() state for the newly
allocated delayed allocation block. Except it doesn't - we're not
marking buffers new correctly.
That buffer_new() problem goes back to the xfs_iomap removal days,
where xfs_iomap() used to return a "new" status for any map with
newly allocated blocks, so that __xfs_get_blocks() could call
set_buffer_new() on it. We still have the "new" variable and the
check for it in the set_buffer_new() logic - except we never set it
now!
Hence that newly allocated delalloc block doesn't have the new flag
set on it, so when the write fails we cannot tell which blocks we
are supposed to punch out. WHy do we need the buffer_new flag? Well,
that's because we can have this case:
+------+------+------+------+------+------+------+------+
UMD UMD UMD UMD UMD UMD UND FAIL
where all the UMD buffers contain valid data from a previously
successful write() system call. We only want to punch the UND buffer
because that's the only one that we added in this write and it was
only this write that failed.
That implies that even the old buffer_new() logic was wrong -
because it would result in all those UMD buffers on the page having
set_buffer_new() called on them even though they aren't new. Hence
we shoul donly be calling set_buffer_new() for delalloc buffers that
were allocated (i.e. were a hole before xfs_iomap_write_delay() was
called).
So, fix this set_buffer_new logic according to how we need it to
work for handling failed writes correctly. Also, restore the new
buffer logic handling for blocks allocated via
xfs_iomap_write_direct(), because it should still set the buffer_new
flag appropriately for newly allocated blocks, too.
SO, now we have the buffer_new() being set appropriately in
__xfs_get_blocks(), we can detect the exact delalloc ranges that
we allocated in a failed write, and hence can now do a walk of the
buffers on a page to find them.
Except, it's not that easy. When block_write_begin() fails, it
unlocks and releases the page that we just had an error on, so we
can't use that page to handle errors anymore. We have to get access
to the page while it is still locked to walk the buffers. Hence we
have to open code block_write_begin() in xfs_vm_write_begin() to be
able to insert xfs_vm_write_failed() is the right place.
With that, we can pass the page and write range to
xfs_vm_write_failed() and walk the buffers on the page, looking for
delalloc buffers that are either new or beyond EOF and punch them
out. Handling buffers beyond EOF ensures we still handle the
existing case that xfs_vm_write_failed() handles.
Of special note is the truncate_pagecache() handling - that only
should be done for pages outside EOF - pages within EOF can still
contain valid, dirty data so we must not punch them out of the
cache.
That just leaves the xfs_vm_write_end() failure handling.
The only failure case here is that we didn't copy the entire range,
and generic_write_end() handles that by zeroing the region of the
page that wasn't copied, we don't have to punch out blocks within
the file because they are guaranteed to contain zeros. Hence we only
have to handle the existing "beyond EOF" case and don't need access
to the buffers on the page. Hence it remains largely unchanged.
Note that xfs_getbmap() can still trip over delalloc blocks beyond
EOF that are left there by speculative delayed allocation. Hence
this bug fix does not solve all known issues with bmap vs delalloc,
but it does fix all the the known accidental occurances of the
problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-27 03:45:21 -06:00
|
|
|
if (unlikely(ret < len)) {
|
|
|
|
struct inode *inode = mapping->host;
|
|
|
|
size_t isize = i_size_read(inode);
|
|
|
|
loff_t to = pos + len;
|
|
|
|
|
|
|
|
if (to > isize) {
|
|
|
|
truncate_pagecache(inode, to, isize);
|
|
|
|
xfs_vm_kill_delalloc_range(inode, isize, to);
|
|
|
|
}
|
|
|
|
}
|
2010-06-04 03:29:58 -06:00
|
|
|
return ret;
|
2006-03-13 19:26:27 -07:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
STATIC sector_t
|
2006-03-13 19:54:26 -07:00
|
|
|
xfs_vm_bmap(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct address_space *mapping,
|
|
|
|
sector_t block)
|
|
|
|
{
|
|
|
|
struct inode *inode = (struct inode *)mapping->host;
|
2007-08-28 18:58:01 -06:00
|
|
|
struct xfs_inode *ip = XFS_I(inode);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-06-23 19:57:09 -06:00
|
|
|
trace_xfs_vm_bmap(XFS_I(inode));
|
2008-03-05 19:44:57 -07:00
|
|
|
xfs_ilock(ip, XFS_IOLOCK_SHARED);
|
2007-08-28 18:58:01 -06:00
|
|
|
xfs_flush_pages(ip, (xfs_off_t)0, -1, 0, FI_REMAPF);
|
2008-03-05 19:44:57 -07:00
|
|
|
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
|
2006-03-28 17:44:40 -07:00
|
|
|
return generic_block_bmap(mapping, block, xfs_get_blocks);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
STATIC int
|
2006-03-13 19:54:26 -07:00
|
|
|
xfs_vm_readpage(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct file *unused,
|
|
|
|
struct page *page)
|
|
|
|
{
|
2006-03-28 17:44:40 -07:00
|
|
|
return mpage_readpage(page, xfs_get_blocks);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
STATIC int
|
2006-03-13 19:54:26 -07:00
|
|
|
xfs_vm_readpages(
|
2005-04-16 16:20:36 -06:00
|
|
|
struct file *unused,
|
|
|
|
struct address_space *mapping,
|
|
|
|
struct list_head *pages,
|
|
|
|
unsigned nr_pages)
|
|
|
|
{
|
2006-03-28 17:44:40 -07:00
|
|
|
return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2006-06-28 05:26:44 -06:00
|
|
|
const struct address_space_operations xfs_address_space_operations = {
|
2006-03-13 19:54:26 -07:00
|
|
|
.readpage = xfs_vm_readpage,
|
|
|
|
.readpages = xfs_vm_readpages,
|
|
|
|
.writepage = xfs_vm_writepage,
|
2006-06-08 23:27:16 -06:00
|
|
|
.writepages = xfs_vm_writepages,
|
2006-03-16 23:26:25 -07:00
|
|
|
.releasepage = xfs_vm_releasepage,
|
|
|
|
.invalidatepage = xfs_vm_invalidatepage,
|
2007-10-16 02:25:06 -06:00
|
|
|
.write_begin = xfs_vm_write_begin,
|
2010-06-14 03:17:31 -06:00
|
|
|
.write_end = xfs_vm_write_end,
|
2006-03-13 19:54:26 -07:00
|
|
|
.bmap = xfs_vm_bmap,
|
|
|
|
.direct_IO = xfs_vm_direct_IO,
|
2006-02-01 04:05:41 -07:00
|
|
|
.migratepage = buffer_migrate_page,
|
2009-03-29 01:53:38 -06:00
|
|
|
.is_partially_uptodate = block_is_partially_uptodate,
|
2009-09-16 03:50:16 -06:00
|
|
|
.error_remove_page = generic_error_remove_page,
|
2005-04-16 16:20:36 -06:00
|
|
|
};
|