The kernel can currently only handle a single hugetlb page fault at a
time. This is due to a single mutex that serializes the entire path.
This lock protects from spurious OOM errors under conditions of low
availability of free hugepages. This problem is specific to hugepages,
because it is normal to want to use every single hugepage in the system
- with normal pages we simply assume there will always be a few spare
pages which can be used temporarily until the race is resolved.
Address this problem by using a table of mutexes, allowing a better
chance of parallelization, where each hugepage is individually
serialized. The hash key is selected depending on the mapping type.
For shared ones it consists of the address space and file offset being
faulted; while for private ones the mm and virtual address are used.
The size of the table is selected based on a compromise of collisions
and memory footprint of a series of database workloads.
Large database workloads that make heavy use of hugepages can be
particularly exposed to this issue, causing start-up times to be
painfully slow. This patch reduces the startup time of a 10 Gb Oracle
DB (with ~5000 faults) from 37.5 secs to 25.7 secs. Larger workloads
will naturally benefit even more.
NOTE:
The only downside to this patch, detected by Joonsoo Kim, is that a
small race is possible in private mappings: A child process (with its
own mm, after cow) can instantiate a page that is already being handled
by the parent in a cow fault. When low on pages, can trigger spurious
OOMs. I have not been able to think of a efficient way of handling
this... but do we really care about such a tiny window? We already
maintain another theoretical race with normal pages. If not, one
possible way to is to maintain the single hash for private mappings --
any workloads that *really* suffer from this scaling problem should
already use shared mappings.
[akpm@linux-foundation.org: remove stray + characters, go BUG if hugetlb_init() kmalloc fails]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Util now, we get a resv_map by two ways according to each mapping type.
This makes code dirty and unreadable. Unify it.
[davidlohr@hp.com: code cleanups]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparation patch to unify the use of vma_resv_map()
regardless of the map type. This patch prepares it by removing
resv_map_put(), which only works for HPAGE_RESV_OWNER's resv_map, not
for all resv_maps.
[davidlohr@hp.com: update changelog]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a race condition if we map a same file on different processes.
Region tracking is protected by mmap_sem and hugetlb_instantiation_mutex.
When we do mmap, we don't grab a hugetlb_instantiation_mutex, but only
mmap_sem (exclusively). This doesn't prevent other tasks from modifying
the region structure, so it can be modified by two processes
concurrently.
To solve this, introduce a spinlock to resv_map and make region
manipulation function grab it before they do actual work.
[davidlohr@hp.com: updated changelog]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To change a protection method for region tracking to find grained one,
we pass the resv_map, instead of list_head, to region manipulation
functions.
This doesn't introduce any functional change, and it is just for
preparing a next step.
[davidlohr@hp.com: update changelog]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, to track reserved and allocated regions, we use two different
ways, depending on the mapping. For MAP_SHARED, we use
address_mapping's private_list and, while for MAP_PRIVATE, we use a
resv_map.
Now, we are preparing to change a coarse grained lock which protect a
region structure to fine grained lock, and this difference hinder it.
So, before changing it, unify region structure handling, consistently
using a resv_map regardless of the kind of mapping.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since put_mems_allowed() is strictly optional, its a seqcount retry, we
don't need to evaluate the function if the allocation was in fact
successful, saving a smp_rmb some loads and comparisons on some relative
fast-paths.
Since the naming, get/put_mems_allowed() does suggest a mandatory
pairing, rename the interface, as suggested by Mel, to resemble the
seqcount interface.
This gives us: read_mems_allowed_begin() and read_mems_allowed_retry(),
where it is important to note that the return value of the latter call
is inverted from its previous incarnation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cached pageblock hint should be ignored when triggering compaction
through /proc/sys/vm/compact_memory so all eligible memory is isolated.
Manually invoking compaction is known to be expensive, there's no need
to skip pageblocks based on heuristics (mainly for debugging).
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no need passing on a shrink_control struct from
try_to_free_pages() and friends to do_try_to_free_pages() and then to
shrink_zones(), because it is only used in shrink_zones() and the only
field initialized on the top level is gfp_mask, which is always equal to
scan_control.gfp_mask. So let's move shrink_control initialization to
shrink_zones().
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reduces the indentation level of do_try_to_free_pages() and removes
extra loop over all eligible zones counting the number of on-LRU pages.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Glauber Costa <glommer@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When direct reclaim is executed by a process bound to a set of NUMA
nodes, we should scan only those nodes when possible, but currently we
will scan kmem from all online nodes even if the kmem shrinker is NUMA
aware. That said, binding a process to a particular NUMA node won't
prevent it from shrinking inode/dentry caches from other nodes, which is
not good. Fix this.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I ran into a scenario where while one cpu was stuck and should have
panic'd because of the NMI watchdog, it didn't. The reason was another
cpu was spewing stack dumps on to the console. Upon investigation, I
noticed that when writing to the console and also when dumping the
stack, the watchdog is touched.
This causes all the cpus to reset their NMI watchdog flags and the
'stuck' cpu just spins forever.
This change causes the semantics of touch_nmi_watchdog to be changed
slightly. Previously, I accidentally changed the semantics and we
noticed there was a codepath in which touch_nmi_watchdog could be
touched from a preemtible area. That caused a BUG() to happen when
CONFIG_DEBUG_PREEMPT was enabled. I believe it was the acpi code.
My attempt here re-introduces the change to have the
touch_nmi_watchdog() code only touch the local cpu instead of all of the
cpus. But instead of using __get_cpu_var(), I use the
__raw_get_cpu_var() version.
This avoids the preemption problem. However my reasoning wasn't because
I was trying to be lazy. Instead I rationalized it as, well if
preemption is enabled then interrupts should be enabled to and the NMI
watchdog will have no reason to trigger. So it won't matter if the
wrong cpu is touched because the percpu interrupt counters the NMI
watchdog uses should still be incrementing.
Don said:
: I'm ok with this patch, though it does alter the behaviour of how
: touch_nmi_watchdog works. For the most part I don't think most callers
: need to touch all of the watchdogs (on each cpu). Perhaps a corner case
: will pop up (the scheduler?? to mimic touch_all_softlockup_watchdogs() ).
:
: But this does address an issue where if a system is locked up and one cpu
: is spewing out useful debug messages (or error messages), the hard lockup
: will fail to go off. We have seen this on RHEL also.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We know that "ret > 0" is true here. These tests were left over from
commit 02afc27fae ('direct-io: Handle O_(D)SYNC AIO') and aren't
needed any more.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The return value of bio_get_nr_vecs() cannot be bigger than
BIO_MAX_PAGES, so we can remove redundant the comparison between
nr_pages and BIO_MAX_PAGES.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the following crash:
kernel BUG at fs/ocfs2/uptodate.c:530!
Modules linked in: ocfs2(F) ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs bridge xen_pciback xen_netback xen_blkback xen_gntalloc xen_gntdev xen_evtchn xenfs xen_privcmd sunrpc 8021q garp stp llc bonding be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi iTCO_wdt iTCO_vendor_support dcdbas coretemp freq_table mperf microcode pcspkr serio_raw bnx2 lpc_ich mfd_core i5k_amb i5000_edac edac_core e1000e sg shpchp ext4(F) jbd2(F) mbcache(F) dm_round_robin(F) sr_mod(F) cdrom(F) usb_storage(F) sd_mod(F) crc_t10dif(F) pata_acpi(F) ata_generic(F) ata_piix(F) mptsas(F) mptscsih(F) mptbase(F) scsi_transport_sas(F) radeon(F)
ttm(F) drm_kms_helper(F) drm(F) hwmon(F) i2c_algo_bit(F) i2c_core(F) dm_multipath(F) dm_mirror(F) dm_region_hash(F) dm_log(F) dm_mod(F)
CPU 5
Pid: 21303, comm: xattr-test Tainted: GF W 3.8.13-30.el6uek.x86_64 #2 Dell Inc. PowerEdge 1950/0M788G
RIP: ocfs2_set_new_buffer_uptodate+0x51/0x60 [ocfs2]
Process xattr-test (pid: 21303, threadinfo ffff880017aca000, task ffff880016a2c480)
Call Trace:
ocfs2_init_xattr_bucket+0x8a/0x120 [ocfs2]
ocfs2_cp_xattr_bucket+0xbb/0x1b0 [ocfs2]
ocfs2_extend_xattr_bucket+0x20a/0x2f0 [ocfs2]
ocfs2_add_new_xattr_bucket+0x23e/0x4b0 [ocfs2]
ocfs2_xattr_set_entry_index_block+0x13c/0x3d0 [ocfs2]
ocfs2_xattr_block_set+0xf9/0x220 [ocfs2]
__ocfs2_xattr_set_handle+0x118/0x710 [ocfs2]
ocfs2_xattr_set+0x691/0x880 [ocfs2]
ocfs2_xattr_user_set+0x46/0x50 [ocfs2]
generic_setxattr+0x96/0xa0
__vfs_setxattr_noperm+0x7b/0x170
vfs_setxattr+0xbc/0xc0
setxattr+0xde/0x230
sys_fsetxattr+0xc6/0xf0
system_call_fastpath+0x16/0x1b
Code: 41 80 0c 24 01 48 89 df e8 7d f0 ff ff 4c 89 e6 48 89 df e8 a2 fe ff ff 48 89 df e8 3a f0 ff ff 48 8b 1c 24 4c 8b 64 24 08 c9 c3 <0f> 0b eb fe 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 66 66
RIP ocfs2_set_new_buffer_uptodate+0x51/0x60 [ocfs2]
It hit the BUG_ON() in ocfs2_set_new_buffer_uptodate():
void ocfs2_set_new_buffer_uptodate(struct ocfs2_caching_info *ci,
struct buffer_head *bh)
{
/* This should definitely *not* exist in our cache */
if (ocfs2_buffer_cached(ci, bh))
printk(KERN_ERR "bh->b_blocknr: %lu @ %p\n", bh->b_blocknr, bh);
BUG_ON(ocfs2_buffer_cached(ci, bh));
set_buffer_uptodate(bh);
ocfs2_metadata_cache_io_lock(ci);
ocfs2_set_buffer_uptodate(ci, bh);
ocfs2_metadata_cache_io_unlock(ci);
}
The problem here is:
We cached a block, but the buffer_head got reused. When we are to pick
up this block again, a new buffer_head created with UPTODATE flag
cleared. ocfs2_buffer_uptodate() returned false since no UPTODATE is
set on the buffer_head. so we set this block to cache as a NEW block,
then it failed at asserting block is not in cache.
The fix is to add a new parameter indicating the bucket is a new
allocated or not to ocfs2_init_xattr_bucket().
ocfs2_init_xattr_bucket() assert block not cached accordingly.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following case may lead to the same system inode ref in confusion.
A thread B thread
ocfs2_get_system_file_inode
->get_local_system_inode
->_ocfs2_get_system_file_inode
because of *arr == NULL,
ocfs2_get_system_file_inode
->get_local_system_inode
->_ocfs2_get_system_file_inode
gets first ref thru
_ocfs2_get_system_file_inode,
gets second ref thru igrab and
set *arr = inode
at the moment, B thread also gets
two refs, so lead to one more
inode ref.
So add mutex lock to avoid multi thread set two inode ref once at the
same time.
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ocfs2_info_handle_freeinode() and ocfs2_test_inode_bit() func, after
calls ocfs2_get_system_file_inode() to get inode ref, if calls
ocfs2_info_scan_inode_alloc() or ocfs2_inode_lock() failed, we should
iput inode alloc to avoid leaking the inode.
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Orabug: 17330860
When accepting an incomming connection o2net_accept_one clones a child
data socket from the parent listening socket. It then proceeds to setup
the child with callback o2net_data_ready() and sk_user_data to NULL. If
data arrives in this window, o2net_listen_data_ready will be called with
some non-deterministic value in sk_user_data (not inherited). We panic
when we page fault on sk_user_data -- in parent it is
sock_def_readable().
The fix is to recognize that this is a data socket being set up by
looking at the socket state and do nothing.
Signed-off-by: Tariq Saseed <tariq.x.saeed@oracle.com>
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After updating alloc_dinode counts in ocfs2_alloc_dinode_update_counts(),
if ocfs2_alloc_dinode_update_bitmap() failed, there is a rare case that
some space may be lost.
So, roll back alloc_dinode counts when ocfs2_block_group_set_bits()
failed.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Younger Liu <younger.liucn@gmail.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2_do_flock() calls ocfs2_file_lock() to get the cross-node clock and
then call flock_lock_file_wait() to compete with local processes. In
case flock_lock_file_wait() failed, say -ENOMEM, clean up work is not
done. This patch adds the cleanup --drop the cross-node lock which was
just granted.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ensure that ocfs2_update_inode_fsync_trans() is called any time we touch
an inode in a given transaction. This is a follow-on to the previous
patch to reduce lock contention and deadlocking during an fsync
operation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Wengang <wen.gang.wang@oracle.com>
Cc: Greg Marsden <greg.marsden@oracle.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Do not put bh when buffer_uptodate failed in ocfs2_write_block and
ocfs2_write_super_or_backup, because it will put bh in b_end_io.
Otherwise it will hit a warning "VFS: brelse: Trying to free free
buffer".
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When ocfs2_create_new_inode_locks() return error, inode open lock may
not be obtainted for this inode. So other nodes can remove this file
and free dinode when inode still remain in memory on this node, which is
not correct and may trigger BUG. So __ocfs2_mknod_locked should return
error when ocfs2_create_new_inode_locks() failed.
Node_1 Node_2
create fileA, call ocfs2_mknod()
-> ocfs2_get_init_inode(), allocate inodeA
-> ocfs2_claim_new_inode(), claim dinode(dinodeA)
-> call ocfs2_create_new_inode_locks(),
create open lock failed, return error
-> __ocfs2_mknod_locked return success
unlink fileA
try open lock succeed,
and free dinodeA
create another file, call ocfs2_mknod()
-> ocfs2_get_init_inode(), allocate inodeB
-> ocfs2_claim_new_inode(), as Node_2 had freed dinodeA,
so claim dinodeA and update generation for dinodeA
call __ocfs2_drop_dl_inodes()->ocfs2_delete_inode()
to free inodeA, and finally triggers BUG
on(inode->i_generation != le32_to_cpu(fe->i_generation))
in function ocfs2_inode_lock_update().
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Orabug: 18108070
ocfs2_xattr_extend_allocation() hits panic when creating xattr during
data extent alloc phase. The problem occurs if due to local alloc
fragmentation, clusters are spread over multiple extents. In this case
ocfs2_add_clusters_in_btree() finds no space to store more than one
extent record and therefore fails returning RESTART_META. The situation
is anticipated for xattr update case but not xattr create case. This
fix simply ports that code to create case.
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In dlm_query_region_handler(), once kmalloc failed, it will unlock
dlm_domain_lock without lock first, then deadlock happens.
Signed-off-by: Zhonghua Guo <guozhonghua@h3c.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Tested-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
llseek requires ocfs2 inode lock for updating the file size in SEEK_END.
because the file size maybe update on another node.
This bug can be reproduce the following scenario: at first, we dd a test
fileA, the file size is 10k.
on NodeA:
---------
1) open the test fileA, lseek the end of file. and print the position.
2) close the test fileA
on NodeB:
1) open the test fileA, append the 5k data to test FileA.
2) lseek the end of file. and print the position.
3) close file.
At first we run the test program1 on NodeA , the result is 10k. And
then run the test program2 on NodeB, the result is 15k. At last, we run
the test program1 on NodeA again, the result is 10k.
After applying this patch the three step result is 15k.
test result: 1000000 times lseek call;
index lseek with inode lock (unit:us) lseek without inode lock (unit:us)
1 1168162 555383
2 1168011 549504
3 1170538 549396
4 1170375 551685
5 1170444 556719
6 1174364 555307
7 1163294 551552
8 1170080 549350
9 1162464 553700
10 1165441 552594
avg 1168317 552519
avg with lock - avg without lock = 615798
(avg with lock - avg without lock)/1000000=0.615798 us
Signed-off-by: Jensen <shencanquan@huawei.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In o2nm_cluster, cl_idle_timeout_ms, cl_keepalive_delay_ms, as well as
cl_reconnect_delay_ms, are defined as type of unsigned int. So we
should also use unsigned int in the helper functions.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following patches are reverted in this patch because these patches
caused performance regression in the remote unlink() calls.
ea455f8ab6 - ocfs2: Push out dropping of dentry lock to ocfs2_wq
f7b1aa69be - ocfs2: Fix deadlock on umount
5fd1318937 - ocfs2: Don't oops in ocfs2_kill_sb on a failed mount
Previous patches in this series removed the possible deadlocks from
downconvert thread so the above patches shouldn't be needed anymore.
The regression is caused because these patches delay the iput() in case
of dentry unlocks. This also delays the unlocking of the open lockres.
The open lockresource is required to test if the inode can be wiped from
disk or not. When the deleting node does not get the open lock, it
marks it as orphan (even though it is not in use by another
node/process) and causes a journal checkpoint. This delays operations
following the inode eviction. This also moves the inode to the orphaned
inode which further causes more I/O and a lot of unneccessary orphans.
The following script can be used to generate the load causing issues:
declare -a create
declare -a remove
declare -a iterations=(1 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384)
unique="`mktemp -u XXXXX`"
script="/tmp/idontknow-${unique}.sh"
cat <<EOF > "${script}"
for n in {1..8}; do mkdir -p test/dir\${n}
eval touch test/dir\${n}/foo{1.."\$1"}
done
EOF
chmod 700 "${script}"
function fcreate ()
{
exec 2>&1 /usr/bin/time --format=%E "${script}" "$1"
}
function fremove ()
{
exec 2>&1 /usr/bin/time --format=%E ssh node2 "cd `pwd`; rm -Rf test*"
}
function fcp ()
{
exec 2>&1 /usr/bin/time --format=%E ssh node3 "cd `pwd`; cp -R test test.new"
}
echo -------------------------------------------------
echo "| # files | create #s | copy #s | remove #s |"
echo -------------------------------------------------
for ((x=0; x < ${#iterations[*]} ; x++)) do
create[$x]="`fcreate ${iterations[$x]}`"
copy[$x]="`fcp ${iterations[$x]}`"
remove[$x]="`fremove`"
printf "| %8d | %9s | %9s | %9s |\n" ${iterations[$x]} ${create[$x]} ${copy[$x]} ${remove[$x]}
done
rm "${script}"
echo "------------------------"
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we are dropping last inode reference from downconvert thread, we will
end up calling ocfs2_mark_lockres_freeing() which can block if the lock
we are freeing is queued thus creating an A-A deadlock. Luckily, since
we are the downconvert thread, we can immediately dequeue the lock and
thus avoid waiting in this case.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference to
a workqueue if it happens from the downconvert thread.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide dqgrab() function to get quota structure reference when we are
sure it already has at least one active reference. Make use of this
function inside quota code.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move dquot_initalize() call in ocfs2_delete_inode() after the moment we
verify inode is actually a sane one to delete. We certainly don't want
to initialize quota for system inodes etc. This also avoids calling
into quota code from downconvert thread.
Add more details into the comment why bailing out from
ocfs2_delete_inode() when we are in downconvert thread is OK.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The flag was never set, delete it.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a part of the nocontrold feature which was incorporated sometime
back.
This is required for backward compatibility of the tools, specifically
the scenario where the tools with recovery callback is used with a
kernel not using the recovery callbacks (older kernel + newer tools).
The tools look for this file to understand if the kernel supports DLM
recovery callbacks.
For kernels which support recovery callbacks but will miss this patch,
ocfs2 will continue to use the older API and would still be able to
mount the filesystem.
[akpm@linux-foundation.org: simplify]
[sfr@canb.auug.org.au: VERIFY_OCTAL_PERMISSIONS fix up]
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a race window in dlm_do_recovery() between dlm_remaster_locks()
and dlm_reset_recovery() when the recovery master nearly finish the
recovery process for a dead node. After the master sends FINALIZE_RECO
message in dlm_remaster_locks(), another node may become the recovery
master for another dead node, and then send the BEGIN_RECO message to
all the nodes included the old master, in the handler of this message
dlm_begin_reco_handler() of old master, dlm->reco.dead_node and
dlm->reco.new_master will be set to the second dead node and the new
master, then in dlm_reset_recovery(), these two variables will be reset
to default value. This will cause new recovery master can not finish
the recovery process and hung, at last the whole cluster will hung for
recovery.
old recovery master: new recovery master:
dlm_remaster_locks()
become recovery master for
another dead node.
dlm_send_begin_reco_message()
dlm_begin_reco_handler()
{
if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
return -EAGAIN;
}
dlm_set_reco_master(dlm, br->node_idx);
dlm_set_reco_dead_node(dlm, br->dead_node);
}
dlm_reset_recovery()
{
dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
}
will hang in dlm_remaster_locks() for
request dlm locks info
Before send FINALIZE_RECO message, recovery master should set
DLM_RECO_STATE_FINALIZE for itself and clear it after the recovery done,
this can break the race windows as the BEGIN_RECO messages will not be
handled before DLM_RECO_STATE_FINALIZE flag is cleared.
A similar race may happen between new recovery master and normal node
which is in dlm_finalize_reco_handler(), also fix it.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This issue was introduced by commit 800deef3f6 ("ocfs2: use
list_for_each_entry where benefical") in 2007 where it replaced
list_for_each with list_for_each_entry. The variable "lock" will point
to invalid data if "tmpq" list is empty and a panic will be triggered
due to this. Sunil advised reverting it back, but the old version was
also not right. At the end of the outer for loop, that
list_for_each_entry will also set "lock" to an invalid data, then in the
next loop, if the "tmpq" list is empty, "lock" will be an stale invalid
data and cause the panic. So reverting the list_for_each back and reset
"lock" to NULL to fix this issue.
Another concern is that this seemes can not happen because the "tmpq"
list should not be empty. Let me describe how.
old lock resource owner(node 1): migratation target(node 2):
image there's lockres with a EX lock from node 2 in
granted list, a NR lock from node x with convert_type
EX in converting list.
dlm_empty_lockres() {
dlm_pick_migration_target() {
pick node 2 as target as its lock is the first one
in granted list.
}
dlm_migrate_lockres() {
dlm_mark_lockres_migrating() {
res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
//after the above code, we can not dirty lockres any more,
// so dlm_thread shuffle list will not run
downconvert lock from EX to NR
upconvert lock from NR to EX
<<< migration may schedule out here, then
<<< node 2 send down convert request to convert type from EX to
<<< NR, then send up convert request to convert type from NR to
<<< EX, at this time, lockres granted list is empty, and two locks
<<< in the converting list, node x up convert lock followed by
<<< node 2 up convert lock.
// will set lockres RES_MIGRATING flag, the following
// lock/unlock can not run
dlm_lockres_release_ast(dlm, res);
}
dlm_send_one_lockres()
dlm_process_recovery_data()
for (i=0; i<mres->num_locks; i++)
if (ml->node == dlm->node_num)
for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
list_for_each_entry(lock, tmpq, list)
if (lock) break; <<< lock is invalid as grant list is empty.
}
if (lock->ml.node != ml->node)
BUG() >>> crash here
}
I see the above locks status from a vmcore of our internal bug.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, ocfs2_sync_file grabs i_mutex and forces the current journal
transaction to complete. This isn't terribly efficient, since sync_file
really only needs to wait for the last transaction involving that inode
to complete, and this doesn't require i_mutex.
Therefore, implement the necessary bits to track the newest tid
associated with an inode, and teach sync_file to wait for that instead
of waiting for everything in the journal to commit. Furthermore, only
issue the flush request to the drive if jbd2 hasn't already done so.
This also eliminates the deadlock between ocfs2_file_aio_write() and
ocfs2_sync_file(). aio_write takes i_mutex then calls
ocfs2_aiodio_wait() to wait for unaligned dio writes to finish.
However, if that dio completion involves calling fsync, then we can get
into trouble when some ocfs2_sync_file tries to take i_mutex.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variable uuid_net_key in ocfs2_initialize_super() is not used. Clean it
up.
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a problem that waitqueue_active() may check stale data thus miss
a wakeup of threads waiting on ip_unaligned_aio.
The valid value of ip_unaligned_aio is only 0 and 1 so we can change it to
be of type mutex thus the above prolem is avoid. Another benifit is that
mutex which works as FIFO is fairer than wake_up_all().
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When mounting an ocfs2 volume, it will firstly generate a file
/sys/kernel/debug/o2dlm/<uuid>/dlm_state, and then launch the dlm thread.
So the following situation will cause a null pointer dereference.
dlm_debug_init -> access file dlm_state which will call dlm_state_print ->
dlm_launch_thread
Move dlm_debug_init after dlm_launch_thread and dlm_launch_recovery_thread
can fix this issue.
Signed-off-by: Zongxun Wang <wangzongxun@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch the RSPI MSTP clock on SH7757 from a con ID match to a dev ID
match, so we can start looking it up using clk_get() with a NULL ID.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler is permitted to generate code which overwrites the
parameters to a function. If those parameters include the only saved
copy we have of userspace's registers, we're in trouble.
Signed-off-by: Bobby Bingham <koorogi@koorogi.info>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This does not appear to have been used since commit 74d99a5e26 ("sh:
SH-2A FPU support") in 2007.
Signed-off-by: Bobby Bingham <koorogi@koorogi.info>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When invoking syscall handlers on sh32, the saved userspace registers
are at the top of the stack. This seems to have been intentional, as it
is an easy way to pass r0, r1, ... to the handler as parameters 5, 6,
...
It causes problems, however, because the compiler is allowed to generate
code for a function which clobbers that function's own parameters. For
example, gcc generates the following code for clone:
<SyS_clone>:
mov.l 8c020714 <SyS_clone+0xc>,r1 ! 8c020540 <do_fork>
mov.l r7,@r15
mov r6,r7
jmp @r1
mov #0,r6
nop
.word 0x0540
.word 0x8c02
The `mov.l r7,@r15` clobbers the saved value of r0 passed from
userspace. For most system calls, this might not be a problem, because
we'll be overwriting r0 with the return value anyway. But in the case
of clone, copy_thread will need the original value of r0 if the
CLONE_SETTLS flag was specified.
The first patch in this series fixes this issue for system calls by
pushing to the stack and extra copy of r0-r2 before invoking the
handler. We discard this copy before restoring the userspace registers,
so it is not a problem if they are clobbered.
Exception handlers also receive the userspace register values in a
similar manner, and may hit the same problem. The second patch removes
the do_fpu_error handler, which looks susceptible to this problem and
which, as far as I can tell, has not been used in some time. The third
patch addresses other exception handlers.
This patch (of 3):
The userspace registers are stored at the top of the stack when the
syscall handler is invoked, which allows r0-r2 to act as parameters 5-7.
Parameters passed on the stack may be clobbered by the syscall handler.
The solution is to push an extra copy of the registers which might be
used as syscall parameters to the stack, so that the authoritative set
of saved register values does not get clobbered.
A few system call handlers are also updated to get the userspace
registers using current_pt_regs() instead of from the stack.
Signed-off-by: Bobby Bingham <koorogi@koorogi.info>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the CPU_SCORE7 Kconfig parameter, which is no longer used
anywhere in the source code and Makefiles.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recent increased use of typeof() throughout the tree resulted in a
number of symbols (25 in a typical distro config of ours) not getting a
proper CRC calculated for them anymore, due to the parser in genksyms
not coping with several of these uses (interestingly in the majority of
[if not all] cases the problem is due to the use of typeof() in code
preceding a certain export, not in the declaration/definition of the
exported function/object itself; I wasn't able to find a way to address
this more general parser shortcoming).
The use of parameter_declaration is a little more relaxed than would be
ideal (permitting not just a bare type specification, but also one with
identifier), but since the same code is being passed through an actual
compiler, there's no apparent risk of allowing through any broken code.
Otoh using parameter_declaration instead of the ad hoc
"decl_specifier_seq '*'" / "decl_specifier_seq" pair allows all types to
be handled rather than just plain ones and pointers to plain ones.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move code moving event structure to access_list from copy_event_to_user()
to fanotify_read() where it is more logical (so that we can immediately
see in the main loop that we either move the event to a different list
or free it). Also move special error handling for permission events
from copy_event_to_user() to the main loop to have it in one place with
error handling for normal events. This makes copy_event_to_user()
really only copy the event to user without any side effects.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso