![Dave Chinner](/assets/img/avatar_default.png)
Now that the background flush code has been fixed, we shouldn't need to silently multiply the wbc->nr_to_write to get good writeback. Remove that code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1742 lines
43 KiB
C
1742 lines
43 KiB
C
/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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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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* published by the Free Software Foundation.
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*
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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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*
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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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*/
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#include "xfs.h"
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#include "xfs_bit.h"
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#include "xfs_log.h"
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#include "xfs_inum.h"
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#include "xfs_sb.h"
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#include "xfs_ag.h"
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#include "xfs_dir2.h"
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#include "xfs_trans.h"
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#include "xfs_dmapi.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_alloc_btree.h"
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#include "xfs_ialloc_btree.h"
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#include "xfs_dir2_sf.h"
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#include "xfs_attr_sf.h"
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#include "xfs_dinode.h"
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#include "xfs_inode.h"
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#include "xfs_alloc.h"
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#include "xfs_btree.h"
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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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#include "xfs_vnodeops.h"
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#include "xfs_trace.h"
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#include "xfs_bmap.h"
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#include <linux/gfp.h>
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#include <linux/mpage.h>
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#include <linux/pagevec.h>
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#include <linux/writeback.h>
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/*
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* Types of I/O for bmap clustering and I/O completion tracking.
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*/
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enum {
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IO_READ, /* mapping for a read */
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IO_DELAY, /* mapping covers delalloc region */
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IO_UNWRITTEN, /* mapping covers allocated but uninitialized data */
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IO_NEW /* just allocated */
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};
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/*
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* Prime number of hash buckets since address is used as the key.
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*/
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#define NVSYNC 37
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#define to_ioend_wq(v) (&xfs_ioend_wq[((unsigned long)v) % NVSYNC])
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static wait_queue_head_t xfs_ioend_wq[NVSYNC];
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void __init
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xfs_ioend_init(void)
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{
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int i;
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for (i = 0; i < NVSYNC; i++)
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init_waitqueue_head(&xfs_ioend_wq[i]);
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}
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void
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xfs_ioend_wait(
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xfs_inode_t *ip)
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{
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wait_queue_head_t *wq = to_ioend_wq(ip);
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wait_event(*wq, (atomic_read(&ip->i_iocount) == 0));
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}
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STATIC void
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xfs_ioend_wake(
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xfs_inode_t *ip)
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{
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if (atomic_dec_and_test(&ip->i_iocount))
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wake_up(to_ioend_wq(ip));
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}
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void
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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 *unmapped,
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int *unwritten)
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{
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struct buffer_head *bh, *head;
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*delalloc = *unmapped = *unwritten = 0;
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bh = head = page_buffers(page);
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do {
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if (buffer_uptodate(bh) && !buffer_mapped(bh))
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(*unmapped) = 1;
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else if (buffer_unwritten(bh))
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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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STATIC struct block_device *
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xfs_find_bdev_for_inode(
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struct inode *inode)
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{
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struct xfs_inode *ip = XFS_I(inode);
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struct xfs_mount *mp = ip->i_mount;
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if (XFS_IS_REALTIME_INODE(ip))
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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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/*
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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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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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struct buffer_head *bh, *next;
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struct xfs_inode *ip = XFS_I(ioend->io_inode);
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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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bh->b_end_io(bh, !ioend->io_error);
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}
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/*
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* Volume managers supporting multiple paths can send back ENODEV
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* when the final path disappears. In this case continuing to fill
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* the page cache with dirty data which cannot be written out is
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* evil, so prevent that.
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*/
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if (unlikely(ioend->io_error == -ENODEV)) {
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xfs_do_force_shutdown(ip->i_mount, SHUTDOWN_DEVICE_REQ,
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__FILE__, __LINE__);
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}
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xfs_ioend_wake(ip);
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mempool_free(ioend, xfs_ioend_pool);
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}
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/*
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* If the end of the current ioend is beyond the current EOF,
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* return the new EOF value, otherwise zero.
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*/
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STATIC xfs_fsize_t
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xfs_ioend_new_eof(
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xfs_ioend_t *ioend)
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{
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xfs_inode_t *ip = XFS_I(ioend->io_inode);
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xfs_fsize_t isize;
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xfs_fsize_t bsize;
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bsize = ioend->io_offset + ioend->io_size;
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isize = MAX(ip->i_size, ip->i_new_size);
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isize = MIN(isize, bsize);
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return isize > ip->i_d.di_size ? isize : 0;
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}
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/*
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* Update on-disk file size now that data has been written to disk. The
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* current in-memory file size is i_size. If a write is beyond eof i_new_size
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* will be the intended file size until i_size is updated. If this write does
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* not extend all the way to the valid file size then restrict this update to
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* the end of the write.
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*
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* This function does not block as blocking on the inode lock in IO completion
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* can lead to IO completion order dependency deadlocks.. If it can't get the
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* inode ilock it will return EAGAIN. Callers must handle this.
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*/
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STATIC int
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xfs_setfilesize(
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xfs_ioend_t *ioend)
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{
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xfs_inode_t *ip = XFS_I(ioend->io_inode);
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xfs_fsize_t isize;
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ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
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ASSERT(ioend->io_type != IO_READ);
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if (unlikely(ioend->io_error))
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return 0;
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if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
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return EAGAIN;
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isize = xfs_ioend_new_eof(ioend);
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if (isize) {
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ip->i_d.di_size = isize;
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xfs_mark_inode_dirty(ip);
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}
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xfs_iunlock(ip, XFS_ILOCK_EXCL);
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return 0;
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}
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/*
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* Schedule IO completion handling on a xfsdatad if this was
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* the final hold on this ioend. If we are asked to wait,
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* flush the workqueue.
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*/
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STATIC void
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xfs_finish_ioend(
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xfs_ioend_t *ioend,
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int wait)
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{
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if (atomic_dec_and_test(&ioend->io_remaining)) {
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struct workqueue_struct *wq;
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wq = (ioend->io_type == IO_UNWRITTEN) ?
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xfsconvertd_workqueue : xfsdatad_workqueue;
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queue_work(wq, &ioend->io_work);
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if (wait)
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flush_workqueue(wq);
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}
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}
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/*
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* IO write completion.
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*/
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STATIC void
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xfs_end_io(
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struct work_struct *work)
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{
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xfs_ioend_t *ioend = container_of(work, xfs_ioend_t, io_work);
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struct xfs_inode *ip = XFS_I(ioend->io_inode);
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int error = 0;
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/*
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* For unwritten extents we need to issue transactions to convert a
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* range to normal written extens after the data I/O has finished.
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*/
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if (ioend->io_type == IO_UNWRITTEN &&
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likely(!ioend->io_error && !XFS_FORCED_SHUTDOWN(ip->i_mount))) {
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error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
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ioend->io_size);
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if (error)
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ioend->io_error = error;
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}
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/*
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* We might have to update the on-disk file size after extending
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* writes.
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*/
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if (ioend->io_type != IO_READ) {
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error = xfs_setfilesize(ioend);
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ASSERT(!error || error == EAGAIN);
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}
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/*
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* If we didn't complete processing of the ioend, requeue it to the
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* tail of the workqueue for another attempt later. Otherwise destroy
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* it.
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*/
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if (error == EAGAIN) {
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atomic_inc(&ioend->io_remaining);
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xfs_finish_ioend(ioend, 0);
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/* ensure we don't spin on blocked ioends */
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delay(1);
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} else
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xfs_destroy_ioend(ioend);
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}
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/*
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* Allocate and initialise an IO completion structure.
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* We need to track unwritten extent write completion here initially.
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* We'll need to extend this for updating the ondisk inode size later
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* (vs. incore size).
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*/
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STATIC xfs_ioend_t *
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xfs_alloc_ioend(
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struct inode *inode,
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unsigned int type)
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{
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xfs_ioend_t *ioend;
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ioend = mempool_alloc(xfs_ioend_pool, GFP_NOFS);
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/*
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* Set the count to 1 initially, which will prevent an I/O
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* completion callback from happening before we have started
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* all the I/O from calling the completion routine too early.
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*/
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atomic_set(&ioend->io_remaining, 1);
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ioend->io_error = 0;
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ioend->io_list = NULL;
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ioend->io_type = type;
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ioend->io_inode = inode;
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ioend->io_buffer_head = NULL;
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ioend->io_buffer_tail = NULL;
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atomic_inc(&XFS_I(ioend->io_inode)->i_iocount);
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ioend->io_offset = 0;
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ioend->io_size = 0;
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INIT_WORK(&ioend->io_work, xfs_end_io);
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return ioend;
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}
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STATIC int
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xfs_map_blocks(
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struct inode *inode,
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loff_t offset,
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ssize_t count,
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struct xfs_bmbt_irec *imap,
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int flags)
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{
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int nmaps = 1;
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int new = 0;
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return -xfs_iomap(XFS_I(inode), offset, count, flags, imap, &nmaps, &new);
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}
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STATIC int
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xfs_imap_valid(
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struct inode *inode,
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struct xfs_bmbt_irec *imap,
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xfs_off_t offset)
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{
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offset >>= inode->i_blkbits;
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return offset >= imap->br_startoff &&
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offset < imap->br_startoff + imap->br_blockcount;
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}
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/*
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* BIO completion handler for buffered IO.
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*/
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STATIC void
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xfs_end_bio(
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struct bio *bio,
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int error)
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{
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xfs_ioend_t *ioend = bio->bi_private;
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ASSERT(atomic_read(&bio->bi_cnt) >= 1);
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ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error;
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/* Toss bio and pass work off to an xfsdatad thread */
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bio->bi_private = NULL;
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bio->bi_end_io = NULL;
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bio_put(bio);
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xfs_finish_ioend(ioend, 0);
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}
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STATIC void
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xfs_submit_ioend_bio(
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struct writeback_control *wbc,
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xfs_ioend_t *ioend,
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struct bio *bio)
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{
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atomic_inc(&ioend->io_remaining);
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bio->bi_private = ioend;
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bio->bi_end_io = xfs_end_bio;
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/*
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* If the I/O is beyond EOF we mark the inode dirty immediately
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* but don't update the inode size until I/O completion.
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*/
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if (xfs_ioend_new_eof(ioend))
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xfs_mark_inode_dirty(XFS_I(ioend->io_inode));
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submit_bio(wbc->sync_mode == WB_SYNC_ALL ?
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WRITE_SYNC_PLUG : WRITE, bio);
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ASSERT(!bio_flagged(bio, BIO_EOPNOTSUPP));
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bio_put(bio);
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}
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STATIC struct bio *
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xfs_alloc_ioend_bio(
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struct buffer_head *bh)
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{
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struct bio *bio;
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int nvecs = bio_get_nr_vecs(bh->b_bdev);
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do {
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bio = bio_alloc(GFP_NOIO, nvecs);
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nvecs >>= 1;
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} while (!bio);
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ASSERT(bio->bi_private == NULL);
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bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
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bio->bi_bdev = bh->b_bdev;
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bio_get(bio);
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return bio;
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}
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STATIC void
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xfs_start_buffer_writeback(
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struct buffer_head *bh)
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{
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ASSERT(buffer_mapped(bh));
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ASSERT(buffer_locked(bh));
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ASSERT(!buffer_delay(bh));
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ASSERT(!buffer_unwritten(bh));
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mark_buffer_async_write(bh);
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set_buffer_uptodate(bh);
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clear_buffer_dirty(bh);
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}
|
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|
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STATIC void
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xfs_start_page_writeback(
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struct page *page,
|
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int clear_dirty,
|
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int buffers)
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{
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ASSERT(PageLocked(page));
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ASSERT(!PageWriteback(page));
|
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if (clear_dirty)
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clear_page_dirty_for_io(page);
|
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set_page_writeback(page);
|
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unlock_page(page);
|
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/* If no buffers on the page are to be written, finish it here */
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if (!buffers)
|
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end_page_writeback(page);
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}
|
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|
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static inline int bio_add_buffer(struct bio *bio, struct buffer_head *bh)
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{
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return bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
|
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}
|
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|
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/*
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* Submit all of the bios for all of the ioends we have saved up, covering the
|
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* initial writepage page and also any probed pages.
|
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*
|
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* Because we may have multiple ioends spanning a page, we need to start
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* writeback on all the buffers before we submit them for I/O. If we mark the
|
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* buffers as we got, then we can end up with a page that only has buffers
|
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* marked async write and I/O complete on can occur before we mark the other
|
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* buffers async write.
|
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*
|
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* The end result of this is that we trip a bug in end_page_writeback() because
|
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* we call it twice for the one page as the code in end_buffer_async_write()
|
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* assumes that all buffers on the page are started at the same time.
|
|
*
|
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* The fix is two passes across the ioend list - one to start writeback on the
|
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* buffer_heads, and then submit them for I/O on the second pass.
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*/
|
|
STATIC void
|
|
xfs_submit_ioend(
|
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struct writeback_control *wbc,
|
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xfs_ioend_t *ioend)
|
|
{
|
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xfs_ioend_t *head = ioend;
|
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xfs_ioend_t *next;
|
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struct buffer_head *bh;
|
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struct bio *bio;
|
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sector_t lastblock = 0;
|
|
|
|
/* Pass 1 - start writeback */
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do {
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next = ioend->io_list;
|
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for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
|
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xfs_start_buffer_writeback(bh);
|
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}
|
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} while ((ioend = next) != NULL);
|
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|
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/* Pass 2 - submit I/O */
|
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ioend = head;
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do {
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next = ioend->io_list;
|
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bio = NULL;
|
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|
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for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
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|
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if (!bio) {
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retry:
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bio = xfs_alloc_ioend_bio(bh);
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} else if (bh->b_blocknr != lastblock + 1) {
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xfs_submit_ioend_bio(wbc, ioend, bio);
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goto retry;
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}
|
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|
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if (bio_add_buffer(bio, bh) != bh->b_size) {
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xfs_submit_ioend_bio(wbc, ioend, bio);
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goto retry;
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}
|
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|
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lastblock = bh->b_blocknr;
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}
|
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if (bio)
|
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xfs_submit_ioend_bio(wbc, ioend, bio);
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xfs_finish_ioend(ioend, 0);
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} while ((ioend = next) != NULL);
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}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
xfs_ioend_wake(XFS_I(ioend->io_inode));
|
|
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,
|
|
xfs_off_t offset,
|
|
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;
|
|
}
|
|
|
|
STATIC void
|
|
xfs_map_buffer(
|
|
struct inode *inode,
|
|
struct buffer_head *bh,
|
|
struct xfs_bmbt_irec *imap,
|
|
xfs_off_t offset)
|
|
{
|
|
sector_t bn;
|
|
struct xfs_mount *m = XFS_I(inode)->i_mount;
|
|
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);
|
|
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
|
|
|
bn = (iomap_bn >> (inode->i_blkbits - BBSHIFT)) +
|
|
((offset - iomap_offset) >> inode->i_blkbits);
|
|
|
|
ASSERT(bn || XFS_IS_REALTIME_INODE(XFS_I(inode)));
|
|
|
|
bh->b_blocknr = bn;
|
|
set_buffer_mapped(bh);
|
|
}
|
|
|
|
STATIC void
|
|
xfs_map_at_offset(
|
|
struct inode *inode,
|
|
struct buffer_head *bh,
|
|
struct xfs_bmbt_irec *imap,
|
|
xfs_off_t offset)
|
|
{
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
|
|
|
lock_buffer(bh);
|
|
xfs_map_buffer(inode, bh, imap, offset);
|
|
bh->b_bdev = xfs_find_bdev_for_inode(inode);
|
|
set_buffer_mapped(bh);
|
|
clear_buffer_delay(bh);
|
|
clear_buffer_unwritten(bh);
|
|
}
|
|
|
|
/*
|
|
* Look for a page at index that is suitable for clustering.
|
|
*/
|
|
STATIC unsigned int
|
|
xfs_probe_page(
|
|
struct page *page,
|
|
unsigned int pg_offset,
|
|
int mapped)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (PageWriteback(page))
|
|
return 0;
|
|
|
|
if (page->mapping && PageDirty(page)) {
|
|
if (page_has_buffers(page)) {
|
|
struct buffer_head *bh, *head;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
if (!buffer_uptodate(bh))
|
|
break;
|
|
if (mapped != buffer_mapped(bh))
|
|
break;
|
|
ret += bh->b_size;
|
|
if (ret >= pg_offset)
|
|
break;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
} else
|
|
ret = mapped ? 0 : PAGE_CACHE_SIZE;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
STATIC size_t
|
|
xfs_probe_cluster(
|
|
struct inode *inode,
|
|
struct page *startpage,
|
|
struct buffer_head *bh,
|
|
struct buffer_head *head,
|
|
int mapped)
|
|
{
|
|
struct pagevec pvec;
|
|
pgoff_t tindex, tlast, tloff;
|
|
size_t total = 0;
|
|
int done = 0, i;
|
|
|
|
/* First sum forwards in this page */
|
|
do {
|
|
if (!buffer_uptodate(bh) || (mapped != buffer_mapped(bh)))
|
|
return total;
|
|
total += bh->b_size;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
/* if we reached the end of the page, sum forwards in following pages */
|
|
tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
|
|
tindex = startpage->index + 1;
|
|
|
|
/* Prune this back to avoid pathological behavior */
|
|
tloff = min(tlast, startpage->index + 64);
|
|
|
|
pagevec_init(&pvec, 0);
|
|
while (!done && tindex <= tloff) {
|
|
unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
|
|
|
|
if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
|
|
break;
|
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
struct page *page = pvec.pages[i];
|
|
size_t pg_offset, pg_len = 0;
|
|
|
|
if (tindex == tlast) {
|
|
pg_offset =
|
|
i_size_read(inode) & (PAGE_CACHE_SIZE - 1);
|
|
if (!pg_offset) {
|
|
done = 1;
|
|
break;
|
|
}
|
|
} else
|
|
pg_offset = PAGE_CACHE_SIZE;
|
|
|
|
if (page->index == tindex && trylock_page(page)) {
|
|
pg_len = xfs_probe_page(page, pg_offset, mapped);
|
|
unlock_page(page);
|
|
}
|
|
|
|
if (!pg_len) {
|
|
done = 1;
|
|
break;
|
|
}
|
|
|
|
total += pg_len;
|
|
tindex++;
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
|
|
return total;
|
|
}
|
|
|
|
/*
|
|
* Test if a given page is suitable for writing as part of an unwritten
|
|
* or delayed allocate extent.
|
|
*/
|
|
STATIC int
|
|
xfs_is_delayed_page(
|
|
struct page *page,
|
|
unsigned int type)
|
|
{
|
|
if (PageWriteback(page))
|
|
return 0;
|
|
|
|
if (page->mapping && page_has_buffers(page)) {
|
|
struct buffer_head *bh, *head;
|
|
int acceptable = 0;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
if (buffer_unwritten(bh))
|
|
acceptable = (type == IO_UNWRITTEN);
|
|
else if (buffer_delay(bh))
|
|
acceptable = (type == IO_DELAY);
|
|
else if (buffer_dirty(bh) && buffer_mapped(bh))
|
|
acceptable = (type == IO_NEW);
|
|
else
|
|
break;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
if (acceptable)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
STATIC int
|
|
xfs_convert_page(
|
|
struct inode *inode,
|
|
struct page *page,
|
|
loff_t tindex,
|
|
struct xfs_bmbt_irec *imap,
|
|
xfs_ioend_t **ioendp,
|
|
struct writeback_control *wbc,
|
|
int startio,
|
|
int all_bh)
|
|
{
|
|
struct buffer_head *bh, *head;
|
|
xfs_off_t end_offset;
|
|
unsigned long p_offset;
|
|
unsigned int type;
|
|
int len, page_dirty;
|
|
int count = 0, done = 0, uptodate = 1;
|
|
xfs_off_t offset = page_offset(page);
|
|
|
|
if (page->index != tindex)
|
|
goto fail;
|
|
if (!trylock_page(page))
|
|
goto fail;
|
|
if (PageWriteback(page))
|
|
goto fail_unlock_page;
|
|
if (page->mapping != inode->i_mapping)
|
|
goto fail_unlock_page;
|
|
if (!xfs_is_delayed_page(page, (*ioendp)->io_type))
|
|
goto fail_unlock_page;
|
|
|
|
/*
|
|
* page_dirty is initially a count of buffers on the page before
|
|
* EOF and is decremented as we move each into a cleanable state.
|
|
*
|
|
* 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.
|
|
*/
|
|
end_offset = min_t(unsigned long long,
|
|
(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
|
|
i_size_read(inode));
|
|
|
|
len = 1 << inode->i_blkbits;
|
|
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;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
if (offset >= end_offset)
|
|
break;
|
|
if (!buffer_uptodate(bh))
|
|
uptodate = 0;
|
|
if (!(PageUptodate(page) || buffer_uptodate(bh))) {
|
|
done = 1;
|
|
continue;
|
|
}
|
|
|
|
if (buffer_unwritten(bh) || buffer_delay(bh)) {
|
|
if (buffer_unwritten(bh))
|
|
type = IO_UNWRITTEN;
|
|
else
|
|
type = IO_DELAY;
|
|
|
|
if (!xfs_imap_valid(inode, imap, offset)) {
|
|
done = 1;
|
|
continue;
|
|
}
|
|
|
|
ASSERT(imap->br_startblock != HOLESTARTBLOCK);
|
|
ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
|
|
|
|
xfs_map_at_offset(inode, bh, imap, offset);
|
|
if (startio) {
|
|
xfs_add_to_ioend(inode, bh, offset,
|
|
type, ioendp, done);
|
|
} else {
|
|
set_buffer_dirty(bh);
|
|
unlock_buffer(bh);
|
|
mark_buffer_dirty(bh);
|
|
}
|
|
page_dirty--;
|
|
count++;
|
|
} else {
|
|
type = IO_NEW;
|
|
if (buffer_mapped(bh) && all_bh && startio) {
|
|
lock_buffer(bh);
|
|
xfs_add_to_ioend(inode, bh, offset,
|
|
type, ioendp, done);
|
|
count++;
|
|
page_dirty--;
|
|
} else {
|
|
done = 1;
|
|
}
|
|
}
|
|
} while (offset += len, (bh = bh->b_this_page) != head);
|
|
|
|
if (uptodate && bh == head)
|
|
SetPageUptodate(page);
|
|
|
|
if (startio) {
|
|
if (count) {
|
|
wbc->nr_to_write--;
|
|
if (wbc->nr_to_write <= 0)
|
|
done = 1;
|
|
}
|
|
xfs_start_page_writeback(page, !page_dirty, count);
|
|
}
|
|
|
|
return done;
|
|
fail_unlock_page:
|
|
unlock_page(page);
|
|
fail:
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
struct xfs_bmbt_irec *imap,
|
|
xfs_ioend_t **ioendp,
|
|
struct writeback_control *wbc,
|
|
int startio,
|
|
int all_bh,
|
|
pgoff_t tlast)
|
|
{
|
|
struct pagevec pvec;
|
|
int done = 0, i;
|
|
|
|
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))
|
|
break;
|
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
done = xfs_convert_page(inode, pvec.pages[i], tindex++,
|
|
imap, ioendp, wbc, startio, all_bh);
|
|
if (done)
|
|
break;
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
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);
|
|
ssize_t len = 1 << inode->i_blkbits;
|
|
|
|
if (!xfs_is_delayed_page(page, IO_DELAY))
|
|
goto out_invalidate;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
goto out_invalidate;
|
|
|
|
xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
|
|
"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 done;
|
|
xfs_fileoff_t offset_fsb;
|
|
xfs_bmbt_irec_t imap;
|
|
int nimaps = 1;
|
|
int error;
|
|
xfs_fsblock_t firstblock;
|
|
xfs_bmap_free_t flist;
|
|
|
|
if (!buffer_delay(bh))
|
|
goto next_buffer;
|
|
|
|
offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
|
|
|
|
/*
|
|
* Map the range first and check that it is a delalloc extent
|
|
* before trying to unmap the range. Otherwise we will be
|
|
* trying to remove a real extent (which requires a
|
|
* transaction) or a hole, which is probably a bad idea...
|
|
*/
|
|
error = xfs_bmapi(NULL, ip, offset_fsb, 1,
|
|
XFS_BMAPI_ENTIRE, NULL, 0, &imap,
|
|
&nimaps, NULL, NULL);
|
|
|
|
if (error) {
|
|
/* something screwed, just bail */
|
|
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
|
|
"page discard failed delalloc mapping lookup.");
|
|
}
|
|
break;
|
|
}
|
|
if (!nimaps) {
|
|
/* nothing there */
|
|
goto next_buffer;
|
|
}
|
|
if (imap.br_startblock != DELAYSTARTBLOCK) {
|
|
/* been converted, ignore */
|
|
goto next_buffer;
|
|
}
|
|
WARN_ON(imap.br_blockcount == 0);
|
|
|
|
/*
|
|
* Note: while we initialise the firstblock/flist pair, they
|
|
* should never be used because blocks should never be
|
|
* allocated or freed for a delalloc extent and hence we need
|
|
* don't cancel or finish them after the xfs_bunmapi() call.
|
|
*/
|
|
xfs_bmap_init(&flist, &firstblock);
|
|
error = xfs_bunmapi(NULL, ip, offset_fsb, 1, 0, 1, &firstblock,
|
|
&flist, NULL, &done);
|
|
|
|
ASSERT(!flist.xbf_count && !flist.xbf_first);
|
|
if (error) {
|
|
/* something screwed, just bail */
|
|
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
|
|
"page discard unable to remove delalloc mapping.");
|
|
}
|
|
break;
|
|
}
|
|
next_buffer:
|
|
offset += len;
|
|
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
out_invalidate:
|
|
xfs_vm_invalidatepage(page, 0);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Calling this without startio set means we are being asked to make a dirty
|
|
* page ready for freeing it's buffers. When called with startio set then
|
|
* we are coming from writepage.
|
|
*
|
|
* When called with startio set it is important that we write the WHOLE
|
|
* page if possible.
|
|
* The bh->b_state's cannot know if any of the blocks or which block for
|
|
* that matter are dirty due to mmap writes, and therefore bh uptodate is
|
|
* only valid if the page itself isn't completely uptodate. Some layers
|
|
* may clear the page dirty flag prior to calling write page, under the
|
|
* assumption the entire page will be written out; by not writing out the
|
|
* whole page the page can be reused before all valid dirty data is
|
|
* written out. Note: in the case of a page that has been dirty'd by
|
|
* mapwrite and but partially setup by block_prepare_write the
|
|
* bh->b_states's will not agree and only ones setup by BPW/BCW will have
|
|
* valid state, thus the whole page must be written out thing.
|
|
*/
|
|
|
|
STATIC int
|
|
xfs_page_state_convert(
|
|
struct inode *inode,
|
|
struct page *page,
|
|
struct writeback_control *wbc,
|
|
int startio,
|
|
int unmapped) /* also implies page uptodate */
|
|
{
|
|
struct buffer_head *bh, *head;
|
|
struct xfs_bmbt_irec imap;
|
|
xfs_ioend_t *ioend = NULL, *iohead = NULL;
|
|
loff_t offset;
|
|
unsigned long p_offset = 0;
|
|
unsigned int type;
|
|
__uint64_t end_offset;
|
|
pgoff_t end_index, last_index;
|
|
ssize_t size, len;
|
|
int flags, err, imap_valid = 0, uptodate = 1;
|
|
int page_dirty, count = 0;
|
|
int trylock = 0;
|
|
int all_bh = unmapped;
|
|
|
|
if (startio) {
|
|
if (wbc->sync_mode == WB_SYNC_NONE && wbc->nonblocking)
|
|
trylock |= BMAPI_TRYLOCK;
|
|
}
|
|
|
|
/* 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))) {
|
|
if (startio)
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* page_dirty is initially a count of buffers on the page before
|
|
* EOF and is decremented as we move each into a cleanable state.
|
|
*
|
|
* 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.
|
|
*/
|
|
end_offset = min_t(unsigned long long,
|
|
(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT, offset);
|
|
len = 1 << inode->i_blkbits;
|
|
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;
|
|
|
|
bh = head = page_buffers(page);
|
|
offset = page_offset(page);
|
|
flags = BMAPI_READ;
|
|
type = IO_NEW;
|
|
|
|
/* TODO: cleanup count and page_dirty */
|
|
|
|
do {
|
|
if (offset >= end_offset)
|
|
break;
|
|
if (!buffer_uptodate(bh))
|
|
uptodate = 0;
|
|
if (!(PageUptodate(page) || buffer_uptodate(bh)) && !startio) {
|
|
/*
|
|
* the iomap is actually still valid, but the ioend
|
|
* isn't. shouldn't happen too often.
|
|
*/
|
|
imap_valid = 0;
|
|
continue;
|
|
}
|
|
|
|
if (imap_valid)
|
|
imap_valid = xfs_imap_valid(inode, &imap, offset);
|
|
|
|
/*
|
|
* First case, map an unwritten extent and prepare for
|
|
* extent state conversion transaction on completion.
|
|
*
|
|
* Second case, allocate space for a delalloc buffer.
|
|
* We can return EAGAIN here in the release page case.
|
|
*
|
|
* Third case, an unmapped buffer was found, and we are
|
|
* in a path where we need to write the whole page out.
|
|
*/
|
|
if (buffer_unwritten(bh) || buffer_delay(bh) ||
|
|
((buffer_uptodate(bh) || PageUptodate(page)) &&
|
|
!buffer_mapped(bh) && (unmapped || startio))) {
|
|
int new_ioend = 0;
|
|
|
|
/*
|
|
* Make sure we don't use a read-only iomap
|
|
*/
|
|
if (flags == BMAPI_READ)
|
|
imap_valid = 0;
|
|
|
|
if (buffer_unwritten(bh)) {
|
|
type = IO_UNWRITTEN;
|
|
flags = BMAPI_WRITE | BMAPI_IGNSTATE;
|
|
} else if (buffer_delay(bh)) {
|
|
type = IO_DELAY;
|
|
flags = BMAPI_ALLOCATE | trylock;
|
|
} else {
|
|
type = IO_NEW;
|
|
flags = BMAPI_WRITE | BMAPI_MMAP;
|
|
}
|
|
|
|
if (!imap_valid) {
|
|
/*
|
|
* if we didn't have a valid mapping then we
|
|
* need to ensure that we put the new mapping
|
|
* in a new ioend structure. This needs to be
|
|
* done to ensure that the ioends correctly
|
|
* reflect the block mappings at io completion
|
|
* for unwritten extent conversion.
|
|
*/
|
|
new_ioend = 1;
|
|
if (type == IO_NEW) {
|
|
size = xfs_probe_cluster(inode,
|
|
page, bh, head, 0);
|
|
} else {
|
|
size = len;
|
|
}
|
|
|
|
err = xfs_map_blocks(inode, offset, size,
|
|
&imap, flags);
|
|
if (err)
|
|
goto error;
|
|
imap_valid = xfs_imap_valid(inode, &imap,
|
|
offset);
|
|
}
|
|
if (imap_valid) {
|
|
xfs_map_at_offset(inode, bh, &imap, offset);
|
|
if (startio) {
|
|
xfs_add_to_ioend(inode, bh, offset,
|
|
type, &ioend,
|
|
new_ioend);
|
|
} else {
|
|
set_buffer_dirty(bh);
|
|
unlock_buffer(bh);
|
|
mark_buffer_dirty(bh);
|
|
}
|
|
page_dirty--;
|
|
count++;
|
|
}
|
|
} else if (buffer_uptodate(bh) && startio) {
|
|
/*
|
|
* we got here because the buffer is already mapped.
|
|
* That means it must already have extents allocated
|
|
* underneath it. Map the extent by reading it.
|
|
*/
|
|
if (!imap_valid || flags != BMAPI_READ) {
|
|
flags = BMAPI_READ;
|
|
size = xfs_probe_cluster(inode, page, bh,
|
|
head, 1);
|
|
err = xfs_map_blocks(inode, offset, size,
|
|
&imap, flags);
|
|
if (err)
|
|
goto error;
|
|
imap_valid = xfs_imap_valid(inode, &imap,
|
|
offset);
|
|
}
|
|
|
|
/*
|
|
* We set the type to IO_NEW in case we are doing a
|
|
* small write at EOF that is extending the file but
|
|
* without needing an allocation. We need to update the
|
|
* file size on I/O completion in this case so it is
|
|
* the same case as having just allocated a new extent
|
|
* that we are writing into for the first time.
|
|
*/
|
|
type = IO_NEW;
|
|
if (trylock_buffer(bh)) {
|
|
ASSERT(buffer_mapped(bh));
|
|
if (imap_valid)
|
|
all_bh = 1;
|
|
xfs_add_to_ioend(inode, bh, offset, type,
|
|
&ioend, !imap_valid);
|
|
page_dirty--;
|
|
count++;
|
|
} else {
|
|
imap_valid = 0;
|
|
}
|
|
} else if ((buffer_uptodate(bh) || PageUptodate(page)) &&
|
|
(unmapped || startio)) {
|
|
imap_valid = 0;
|
|
}
|
|
|
|
if (!iohead)
|
|
iohead = ioend;
|
|
|
|
} while (offset += len, ((bh = bh->b_this_page) != head));
|
|
|
|
if (uptodate && bh == head)
|
|
SetPageUptodate(page);
|
|
|
|
if (startio)
|
|
xfs_start_page_writeback(page, 1, count);
|
|
|
|
if (ioend && imap_valid) {
|
|
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;
|
|
|
|
xfs_cluster_write(inode, page->index + 1, &imap, &ioend,
|
|
wbc, startio, all_bh, end_index);
|
|
}
|
|
|
|
if (iohead)
|
|
xfs_submit_ioend(wbc, iohead);
|
|
|
|
return page_dirty;
|
|
|
|
error:
|
|
if (iohead)
|
|
xfs_cancel_ioend(iohead);
|
|
|
|
/*
|
|
* If it's delalloc and we have nowhere to put it,
|
|
* throw it away, unless the lower layers told
|
|
* us to try again.
|
|
*/
|
|
if (err != -EAGAIN) {
|
|
if (!unmapped)
|
|
xfs_aops_discard_page(page);
|
|
ClearPageUptodate(page);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* writepage: Called from one of two places:
|
|
*
|
|
* 1. we are flushing a delalloc buffer head.
|
|
*
|
|
* 2. we are writing out a dirty page. Typically the page dirty
|
|
* state is cleared before we get here. In this case is it
|
|
* conceivable we have no buffer heads.
|
|
*
|
|
* For delalloc space on the page we need to allocate space and
|
|
* flush it. For unmapped buffer heads on the page we should
|
|
* allocate space if the page is uptodate. For any other dirty
|
|
* buffer heads on the page we should flush them.
|
|
*
|
|
* If we detect that a transaction would be required to flush
|
|
* the page, we have to check the process flags first, if we
|
|
* are already in a transaction or disk I/O during allocations
|
|
* is off, we need to fail the writepage and redirty the page.
|
|
*/
|
|
|
|
STATIC int
|
|
xfs_vm_writepage(
|
|
struct page *page,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int error;
|
|
int need_trans;
|
|
int delalloc, unmapped, unwritten;
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
trace_xfs_writepage(inode, page, 0);
|
|
|
|
/*
|
|
* Refuse to write the page out if we are called from reclaim context.
|
|
*
|
|
* This is primarily to avoid stack overflows when called from deep
|
|
* used stacks in random callers for direct reclaim, but disabling
|
|
* reclaim for kswap is a nice side-effect as kswapd causes rather
|
|
* suboptimal I/O patters, too.
|
|
*
|
|
* This should really be done by the core VM, but until that happens
|
|
* filesystems like XFS, btrfs and ext4 have to take care of this
|
|
* by themselves.
|
|
*/
|
|
if (current->flags & PF_MEMALLOC)
|
|
goto out_fail;
|
|
|
|
/*
|
|
* We need a transaction if:
|
|
* 1. There are delalloc buffers on the page
|
|
* 2. The page is uptodate and we have unmapped buffers
|
|
* 3. The page is uptodate and we have no buffers
|
|
* 4. There are unwritten buffers on the page
|
|
*/
|
|
|
|
if (!page_has_buffers(page)) {
|
|
unmapped = 1;
|
|
need_trans = 1;
|
|
} else {
|
|
xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
|
|
if (!PageUptodate(page))
|
|
unmapped = 0;
|
|
need_trans = delalloc + unmapped + unwritten;
|
|
}
|
|
|
|
/*
|
|
* If we need a transaction and the process flags say
|
|
* we are already in a transaction, or no IO is allowed
|
|
* then mark the page dirty again and leave the page
|
|
* as is.
|
|
*/
|
|
if (current_test_flags(PF_FSTRANS) && need_trans)
|
|
goto out_fail;
|
|
|
|
/*
|
|
* Delay hooking up buffer heads until we have
|
|
* made our go/no-go decision.
|
|
*/
|
|
if (!page_has_buffers(page))
|
|
create_empty_buffers(page, 1 << inode->i_blkbits, 0);
|
|
|
|
/*
|
|
* Convert delayed allocate, unwritten or unmapped space
|
|
* to real space and flush out to disk.
|
|
*/
|
|
error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
|
|
if (error == -EAGAIN)
|
|
goto out_fail;
|
|
if (unlikely(error < 0))
|
|
goto out_unlock;
|
|
|
|
return 0;
|
|
|
|
out_fail:
|
|
redirty_page_for_writepage(wbc, page);
|
|
unlock_page(page);
|
|
return 0;
|
|
out_unlock:
|
|
unlock_page(page);
|
|
return error;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vm_writepages(
|
|
struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
|
|
return generic_writepages(mapping, wbc);
|
|
}
|
|
|
|
/*
|
|
* Called to move a page into cleanable state - and from there
|
|
* to be released. Possibly the page is already clean. We always
|
|
* have buffer heads in this call.
|
|
*
|
|
* Returns 0 if the page is ok to release, 1 otherwise.
|
|
*
|
|
* Possible scenarios are:
|
|
*
|
|
* 1. We are being called to release a page which has been written
|
|
* to via regular I/O. buffer heads will be dirty and possibly
|
|
* delalloc. If no delalloc buffer heads in this case then we
|
|
* can just return zero.
|
|
*
|
|
* 2. We are called to release a page which has been written via
|
|
* mmap, all we need to do is ensure there is no delalloc
|
|
* state in the buffer heads, if not we can let the caller
|
|
* free them and we should come back later via writepage.
|
|
*/
|
|
STATIC int
|
|
xfs_vm_releasepage(
|
|
struct page *page,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
int dirty, delalloc, unmapped, unwritten;
|
|
struct writeback_control wbc = {
|
|
.sync_mode = WB_SYNC_ALL,
|
|
.nr_to_write = 1,
|
|
};
|
|
|
|
trace_xfs_releasepage(inode, page, 0);
|
|
|
|
if (!page_has_buffers(page))
|
|
return 0;
|
|
|
|
xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
|
|
if (!delalloc && !unwritten)
|
|
goto free_buffers;
|
|
|
|
if (!(gfp_mask & __GFP_FS))
|
|
return 0;
|
|
|
|
/* If we are already inside a transaction or the thread cannot
|
|
* do I/O, we cannot release this page.
|
|
*/
|
|
if (current_test_flags(PF_FSTRANS))
|
|
return 0;
|
|
|
|
/*
|
|
* Convert delalloc space to real space, do not flush the
|
|
* data out to disk, that will be done by the caller.
|
|
* Never need to allocate space here - we will always
|
|
* come back to writepage in that case.
|
|
*/
|
|
dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
|
|
if (dirty == 0 && !unwritten)
|
|
goto free_buffers;
|
|
return 0;
|
|
|
|
free_buffers:
|
|
return try_to_free_buffers(page);
|
|
}
|
|
|
|
STATIC int
|
|
__xfs_get_blocks(
|
|
struct inode *inode,
|
|
sector_t iblock,
|
|
struct buffer_head *bh_result,
|
|
int create,
|
|
int direct,
|
|
bmapi_flags_t flags)
|
|
{
|
|
struct xfs_bmbt_irec imap;
|
|
xfs_off_t offset;
|
|
ssize_t size;
|
|
int nimap = 1;
|
|
int new = 0;
|
|
int error;
|
|
|
|
offset = (xfs_off_t)iblock << inode->i_blkbits;
|
|
ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
|
|
size = bh_result->b_size;
|
|
|
|
if (!create && direct && offset >= i_size_read(inode))
|
|
return 0;
|
|
|
|
error = xfs_iomap(XFS_I(inode), offset, size,
|
|
create ? flags : BMAPI_READ, &imap, &nimap, &new);
|
|
if (error)
|
|
return -error;
|
|
if (nimap == 0)
|
|
return 0;
|
|
|
|
if (imap.br_startblock != HOLESTARTBLOCK &&
|
|
imap.br_startblock != DELAYSTARTBLOCK) {
|
|
/*
|
|
* For unwritten extents do not report a disk address on
|
|
* the read case (treat as if we're reading into a hole).
|
|
*/
|
|
if (create || !ISUNWRITTEN(&imap))
|
|
xfs_map_buffer(inode, bh_result, &imap, offset);
|
|
if (create && ISUNWRITTEN(&imap)) {
|
|
if (direct)
|
|
bh_result->b_private = inode;
|
|
set_buffer_unwritten(bh_result);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If this is a realtime file, data may be on a different device.
|
|
* to that pointed to from the buffer_head b_bdev currently.
|
|
*/
|
|
bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (create &&
|
|
((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
|
|
(offset >= i_size_read(inode)) ||
|
|
(new || ISUNWRITTEN(&imap))))
|
|
set_buffer_new(bh_result);
|
|
|
|
if (imap.br_startblock == DELAYSTARTBLOCK) {
|
|
BUG_ON(direct);
|
|
if (create) {
|
|
set_buffer_uptodate(bh_result);
|
|
set_buffer_mapped(bh_result);
|
|
set_buffer_delay(bh_result);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (direct || size > (1 << inode->i_blkbits)) {
|
|
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;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
xfs_get_blocks(
|
|
struct inode *inode,
|
|
sector_t iblock,
|
|
struct buffer_head *bh_result,
|
|
int create)
|
|
{
|
|
return __xfs_get_blocks(inode, iblock,
|
|
bh_result, create, 0, BMAPI_WRITE);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_get_blocks_direct(
|
|
struct inode *inode,
|
|
sector_t iblock,
|
|
struct buffer_head *bh_result,
|
|
int create)
|
|
{
|
|
return __xfs_get_blocks(inode, iblock,
|
|
bh_result, create, 1, BMAPI_WRITE|BMAPI_DIRECT);
|
|
}
|
|
|
|
STATIC void
|
|
xfs_end_io_direct(
|
|
struct kiocb *iocb,
|
|
loff_t offset,
|
|
ssize_t size,
|
|
void *private)
|
|
{
|
|
xfs_ioend_t *ioend = iocb->private;
|
|
|
|
/*
|
|
* Non-NULL private data means we need to issue a transaction to
|
|
* convert a range from unwritten to written extents. This needs
|
|
* to happen from process context but aio+dio I/O completion
|
|
* happens from irq context so we need to defer it to a workqueue.
|
|
* This is not necessary for synchronous direct I/O, but we do
|
|
* it anyway to keep the code uniform and simpler.
|
|
*
|
|
* Well, if only it were that simple. Because synchronous direct I/O
|
|
* requires extent conversion to occur *before* we return to userspace,
|
|
* we have to wait for extent conversion to complete. Look at the
|
|
* iocb that has been passed to us to determine if this is AIO or
|
|
* not. If it is synchronous, tell xfs_finish_ioend() to kick the
|
|
* workqueue and wait for it to complete.
|
|
*
|
|
* The core direct I/O code might be changed to always call the
|
|
* completion handler in the future, in which case all this can
|
|
* go away.
|
|
*/
|
|
ioend->io_offset = offset;
|
|
ioend->io_size = size;
|
|
if (ioend->io_type == IO_READ) {
|
|
xfs_finish_ioend(ioend, 0);
|
|
} else if (private && size > 0) {
|
|
xfs_finish_ioend(ioend, is_sync_kiocb(iocb));
|
|
} else {
|
|
/*
|
|
* A direct I/O write ioend starts it's life in unwritten
|
|
* state in case they map an unwritten extent. This write
|
|
* didn't map an unwritten extent so switch it's completion
|
|
* handler.
|
|
*/
|
|
ioend->io_type = IO_NEW;
|
|
xfs_finish_ioend(ioend, 0);
|
|
}
|
|
|
|
/*
|
|
* blockdev_direct_IO can return an error even after the I/O
|
|
* completion handler was called. Thus we need to protect
|
|
* against double-freeing.
|
|
*/
|
|
iocb->private = NULL;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_vm_direct_IO(
|
|
int rw,
|
|
struct kiocb *iocb,
|
|
const struct iovec *iov,
|
|
loff_t offset,
|
|
unsigned long nr_segs)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct block_device *bdev;
|
|
ssize_t ret;
|
|
|
|
bdev = xfs_find_bdev_for_inode(inode);
|
|
|
|
iocb->private = xfs_alloc_ioend(inode, rw == WRITE ?
|
|
IO_UNWRITTEN : IO_READ);
|
|
|
|
ret = blockdev_direct_IO_no_locking(rw, iocb, inode, bdev, iov,
|
|
offset, nr_segs,
|
|
xfs_get_blocks_direct,
|
|
xfs_end_io_direct);
|
|
|
|
if (unlikely(ret != -EIOCBQUEUED && iocb->private))
|
|
xfs_destroy_ioend(iocb->private);
|
|
return ret;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vm_write_begin(
|
|
struct file *file,
|
|
struct address_space *mapping,
|
|
loff_t pos,
|
|
unsigned len,
|
|
unsigned flags,
|
|
struct page **pagep,
|
|
void **fsdata)
|
|
{
|
|
*pagep = NULL;
|
|
return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
|
|
xfs_get_blocks);
|
|
}
|
|
|
|
STATIC sector_t
|
|
xfs_vm_bmap(
|
|
struct address_space *mapping,
|
|
sector_t block)
|
|
{
|
|
struct inode *inode = (struct inode *)mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
|
|
xfs_itrace_entry(XFS_I(inode));
|
|
xfs_ilock(ip, XFS_IOLOCK_SHARED);
|
|
xfs_flush_pages(ip, (xfs_off_t)0, -1, 0, FI_REMAPF);
|
|
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
|
|
return generic_block_bmap(mapping, block, xfs_get_blocks);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vm_readpage(
|
|
struct file *unused,
|
|
struct page *page)
|
|
{
|
|
return mpage_readpage(page, xfs_get_blocks);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vm_readpages(
|
|
struct file *unused,
|
|
struct address_space *mapping,
|
|
struct list_head *pages,
|
|
unsigned nr_pages)
|
|
{
|
|
return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
|
|
}
|
|
|
|
const struct address_space_operations xfs_address_space_operations = {
|
|
.readpage = xfs_vm_readpage,
|
|
.readpages = xfs_vm_readpages,
|
|
.writepage = xfs_vm_writepage,
|
|
.writepages = xfs_vm_writepages,
|
|
.sync_page = block_sync_page,
|
|
.releasepage = xfs_vm_releasepage,
|
|
.invalidatepage = xfs_vm_invalidatepage,
|
|
.write_begin = xfs_vm_write_begin,
|
|
.write_end = generic_write_end,
|
|
.bmap = xfs_vm_bmap,
|
|
.direct_IO = xfs_vm_direct_IO,
|
|
.migratepage = buffer_migrate_page,
|
|
.is_partially_uptodate = block_is_partially_uptodate,
|
|
.error_remove_page = generic_error_remove_page,
|
|
};
|