Microsoft has a bug with ntlmv2 that requires use of ntlmssp, but
we didn't get the required information on when/how to use ntlmssp to
old (but once very popular) legacy servers (various NT4 fixpacks
for example) until too late to merge for 3.1. Will upgrade
to NTLMv2 in NTLMSSP in 3.2
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Fix sec=ntlmv2/i authentication option during mount of Samba shares.
cifs client was coding ntlmv2 response incorrectly.
All that is needed in temp as specified in MS-NLMP seciton 3.3.2
"Define ComputeResponse(NegFlg, ResponseKeyNT, ResponseKeyLM,
CHALLENGE_MESSAGE.ServerChallenge, ClientChallenge, Time, ServerName)
as
Set temp to ConcatenationOf(Responserversion, HiResponserversion,
Z(6), Time, ClientChallenge, Z(4), ServerName, Z(4)"
is MsvAvNbDomainName.
For sec=ntlmsspi, build_av_pair is not used, a blob is plucked from
type 2 response sent by the server to use in authentication.
I tested sec=ntlmv2/i and sec=ntlmssp/i mount options against
Samba (3.6) and Windows - XP, 2003 Server and 7.
They all worked.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Both these options are started with "rw" - that's why the first one
isn't switched on even if it is specified. Fix this by adding a length
check for "rw" option check.
Cc: <stable@kernel.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
move it to the beginning of the loop.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The name_len variable in CIFSFindNext is a signed int that gets set to
the resume_name_len in the cifs_search_info. The resume_name_len however
is unsigned and for some infolevels is populated directly from a 32 bit
value sent by the server.
If the server sends a very large value for this, then that value could
look negative when converted to a signed int. That would make that
value pass the PATH_MAX check later in CIFSFindNext. The name_len would
then be used as a length value for a memcpy. It would then be treated
as unsigned again, and the memcpy scribbles over a ton of memory.
Fix this by making the name_len an unsigned value in CIFSFindNext.
Cc: <stable@kernel.org>
Reported-by: Darren Lavender <dcl@hppine99.gbr.hp.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'for-linus' of git://github.com/chrismason/linux:
Btrfs: only clear the need lookup flag after the dentry is setup
BTRFS: Fix lseek return value for error
Btrfs: don't change inode flag of the dest clone file
Btrfs: don't make a file partly checksummed through file clone
Btrfs: fix pages truncation in btrfs_ioctl_clone()
btrfs: fix d_off in the first dirent
We can race with readdir and the RCU path walking stuff. This is because we
clear the need lookup flag before actually instantiating the inode. This will
lead the RCU path walk stuff to find a dentry it thinks is valid without a
d_inode attached. So instead unhash the dentry when we first start the lookup,
and then clear the flag after we've instantiated the dentry so we're garunteed
to either try the slow lookup, or have the d_inode set properly.
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The recent reworking of btrfs' lseek lead to incorrect
values being returned. This adds checks for seeking
beyond EOF in SEEK_HOLE and makes sure the error
values come back correct.
Andi Kleen also sent in similar patches.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The dst file will have the same inode flags with dst file after
file clone, and I think it's unexpected.
For example, the dst file will suddenly become immutable after
getting some share of data with src file, if the src is immutable.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
To reproduce the bug:
# mount /dev/sda7 /mnt
# dd if=/dev/zero of=/mnt/src bs=4K count=1
# umount /mnt
# mount -o nodatasum /dev/sda7 /mnt
# dd if=/dev/zero of=/mnt/dst bs=4K count=1
# clone_range -s 4K -l 4K /mnt/src /mnt/dst
# echo 3 > /proc/sys/vm/drop_caches
# cat /mnt/dst
# dmesg
...
btrfs no csum found for inode 258 start 0
btrfs csum failed ino 258 off 0 csum 2566472073 private 0
It's because part of the file is checksummed and the other part is not,
and then btrfs will complain checksum is not found when we read the file.
Disallow file clone if src and dst file have different checksum flag,
so we ensure a file is completely checksummed or unchecksummed.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
It's a bug in commit f81c9cdc56
(Btrfs: truncate pages from clone ioctl target range)
We should pass the dest range to the truncate function, but not the
src range.
Also move the function before locking extent state.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Since the d_off in the first dirent for "." (that originates from
the 4th argument "offset" of filldir() for the 2nd dirent for "..")
is wrongly assigned in btrfs_real_readdir(), telldir returns same
offset for different locations.
| # mkfs.btrfs /dev/sdb1
| # mount /dev/sdb1 fs0
| # cd fs0
| # touch file0 file1
| # ../test
| telldir: 0
| readdir: d_off = 2, d_name = "."
| telldir: 2
| readdir: d_off = 2, d_name = ".."
| telldir: 2
| readdir: d_off = 3, d_name = "file0"
| telldir: 3
| readdir: d_off = 2147483647, d_name = "file1"
| telldir: 2147483647
To fix this problem, pass filp->f_pos (which is loff_t) instead.
| # ../test
| telldir: 0
| readdir: d_off = 1, d_name = "."
| telldir: 1
| readdir: d_off = 2, d_name = ".."
| telldir: 2
| readdir: d_off = 3, d_name = "file0"
:
At the moment the "offset" for "." is unused because there is no
preceding dirent, however it is better to pass filp->f_pos to follow
grammatical usage.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
nfs: Do not allow multiple mounts on same mountpoint when using -o noac
NFS: Fix a typo in nfs_flush_multi
NFSv4: renewd needs to be able to handle the NFS4ERR_CB_PATH_DOWN error
NFSv4: The NFSv4.0 client must send RENEW calls if it holds a delegation
NFSv4: nfs4_proc_renew should be declared static
NFSv4: nfs4_proc_async_renew should use a GFP_NOFS allocation
generic_check_addressable can't deal with hfsplus's larger than page
size allocation blocks, so simply opencode the checks that we actually
need in hfsplus_fill_super.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Reported-by: Pavel Ivanov <paivanof@gmail.com>
Tested-by: Pavel Ivanov <paivanof@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 6596528e39 ("hfsplus: ensure bio requests are not smaller than
the hardware sectors") changed the pointers used for volume header
allocations but failed to free the correct pointers in the error path
path of hfsplus_fill_super() and hfsplus_read_wrapper.
The second hunk came from a separate patch by Pavel Ivanov.
Reported-by: Pavel Ivanov <paivanof@gmail.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We used to get the victim pinned by dentry_unhash() prior to commit
64252c75a2 ("vfs: remove dget() from dentry_unhash()") and ->rmdir()
and ->rename() instances relied on that; most of them don't care, but
ones that used d_delete() themselves do. As the result, we are getting
rmdir() oopses on NFS now.
Just grab the reference before locking the victim and drop it explicitly
after unlocking, same as vfs_rename_other() does.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Simon Kirby <sim@hostway.ca>
Cc: stable@kernel.org (3.0.x)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a window in which the ioend that we call inode_dio_wake on
in xfs_end_io_direct_write is already free. Fix this by storing
the inode pointer in a local variable.
This is a fix for the regression introduced in 3.1-rc by
"fs: move inode_dio_done to the end_io handler".
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Do not allow multiple mounts on same mountpoint when using -o noac
When you normally attempt to mount a share twice on the same mountpoint,
a check in do_add_mount causes it to return an error
# mount localhost:/nfsv3 /mnt
# mount localhost:/nfsv3 /mnt
mount.nfs: /mnt is already mounted or busy
However when using the option 'noac', the user is able to mount the same
share on the same mountpoint multiple times. This happens because a
share mounted with the noac option is automatically assigned the 'sync'
flag MS_SYNCHRONOUS in nfs_initialise_sb(). This flag is set after the
check for already existing superblocks is done in sget(). The check for
the mount flags in nfs_compare_mount_options() does not take into
account the 'sync' flag applied later on in the code path. This means
that when using 'noac', a new superblock structure is assigned for every
new mount of the same share and multiple shares on the same mountpoint
are allowed.
ie.
# mount -onoac localhost:/nfsv3 /mnt
can be run multiple times.
The patch checks for noac and assigns the sync flag before sget() is
called to obtain an already existing superblock structure.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix a typo which causes an Oops in the RPC layer, when using wsize < 4k.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Sricharan R <r.sricharan@ti.com>
* 'for-linus' of git://github.com/chrismason/linux:
Btrfs: add dummy extent if dst offset excceeds file end in
Btrfs: calc file extent num_bytes correctly in file clone
btrfs: xattr: fix attribute removal
Btrfs: fix wrong nbytes information of the inode
Btrfs: fix the file extent gap when doing direct IO
Btrfs: fix unclosed transaction handle in btrfs_cont_expand
Btrfs: fix misuse of trans block rsv
Btrfs: reset to appropriate block rsv after orphan operations
Btrfs: skip locking if searching the commit root in csum lookup
btrfs: fix warning in iput for bad-inode
Btrfs: fix an oops when deleting snapshots
Commit 37fb3a30b4 ("fuse: fix flock") added in 3.1-rc4 caused flock() to
fail with ENOSYS with the kernel ABI version 7.16 or earlier.
Fix by falling back to testing FUSE_POSIX_LOCKS for ABI versions 7.16
and earlier.
Reported-by: Martin Ziegler <ziegler@email.mathematik.uni-freiburg.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Martin Ziegler <ziegler@email.mathematik.uni-freiburg.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
You can see there's no file extent with range [0, 4096]. Check this by
btrfsck:
# btrfsck /dev/sda7
root 5 inode 258 errors 100
...
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
An attribute is not removed by 'setfattr -x attr file' and remains
visible in attr list. This makes xfstests/062 pass again.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If we write some data into the data hole of the file(no preallocation for this
hole), Btrfs will allocate some disk space, and update nbytes of the inode, but
the other element--disk_i_size needn't be updated. At this condition, we must
update inode metadata though disk_i_size is not changed(btrfs_ordered_update_i_size()
return 1).
# mkfs.btrfs /dev/sdb1
# mount /dev/sdb1 /mnt
# touch /mnt/a
# truncate -s 856002 /mnt/a
# dd if=/dev/zero of=/mnt/a bs=4K count=1 conv=nocreat,notrunc
# umount /mnt
# btrfsck /dev/sdb1
root 5 inode 257 errors 400
found 32768 bytes used err is 1
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we write some data to the place that is beyond the end of the file
in direct I/O mode, a data hole will be created. And Btrfs should insert
a file extent item that point to this hole into the fs tree. But unfortunately
Btrfs forgets doing it.
The following is a simple way to reproduce it:
# mkfs.btrfs /dev/sdc2
# mount /dev/sdc2 /test4
# touch /test4/a
# dd if=/dev/zero of=/test4/a seek=8 count=1 bs=4K oflag=direct conv=nocreat,notrunc
# umount /test4
# btrfsck /dev/sdc2
root 5 inode 257 errors 100
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The function - btrfs_cont_expand() forgot to close the transaction handle before
it jump out the while loop. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
At the beginning of create_pending_snapshot, trans->block_rsv is set
to pending->block_rsv and is used for snapshot things, however, when
it is done, we do not recover it as will.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
While truncating free space cache, we forget to change trans->block_rsv
back to the original one, but leave it with the orphan_block_rsv, and
then with option inode_cache enable, it leads to countless warnings of
btrfs_alloc_free_block and btrfs_orphan_commit_root:
WARNING: at fs/btrfs/extent-tree.c:5711 btrfs_alloc_free_block+0x180/0x350 [btrfs]()
...
WARNING: at fs/btrfs/inode.c:2193 btrfs_orphan_commit_root+0xb0/0xc0 [btrfs]()
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
It's not enough to just search the commit root, since we could be cow'ing the
very block we need to search through, which would mean that its locked and we'll
still deadlock. So use path->skip_locking as well. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
iput() shouldn't be called for inodes in I_NEW state.
We need to mark inode as constructed first.
WARNING: at fs/inode.c:1309 iput+0x20b/0x210()
Call Trace:
[<ffffffff8103e7ba>] warn_slowpath_common+0x7a/0xb0
[<ffffffff8103e805>] warn_slowpath_null+0x15/0x20
[<ffffffff810eaf0b>] iput+0x20b/0x210
[<ffffffff811b96fb>] btrfs_iget+0x1eb/0x4a0
[<ffffffff811c3ad6>] btrfs_run_defrag_inodes+0x136/0x210
[<ffffffff811ad55f>] cleaner_kthread+0x17f/0x1a0
[<ffffffff81035b7d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffff811ad3e0>] ? transaction_kthread+0x280/0x280
[<ffffffff8105af86>] kthread+0x96/0xa0
[<ffffffff814336d4>] kernel_thread_helper+0x4/0x10
[<ffffffff8105aef0>] ? kthread_worker_fn+0x190/0x190
[<ffffffff814336d0>] ? gs_change+0xb/0xb
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
CC: Konstantin Khlebnikov <khlebnikov@openvz.org>
Tested-by: David Sterba <dsterba@suse.cz>
CC: Josef Bacik <josef@redhat.com>
CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We can reproduce this oops via the following steps:
$ mkfs.btrfs /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs
$ for ((i=0; i<3; i++)); do btrfs sub snap /mnt/btrfs /mnt/btrfs/s_$i; done
$ rm -fr /mnt/btrfs/*
$ rm -fr /mnt/btrfs/*
then we'll get
------------[ cut here ]------------
kernel BUG at fs/btrfs/inode.c:2264!
[...]
Call Trace:
[<ffffffffa05578c7>] btrfs_rmdir+0xf7/0x1b0 [btrfs]
[<ffffffff81150b95>] vfs_rmdir+0xa5/0xf0
[<ffffffff81153cc3>] do_rmdir+0x123/0x140
[<ffffffff81145ac7>] ? fput+0x197/0x260
[<ffffffff810aecff>] ? audit_syscall_entry+0x1bf/0x1f0
[<ffffffff81153d0d>] sys_unlinkat+0x2d/0x40
[<ffffffff8147896b>] system_call_fastpath+0x16/0x1b
RIP [<ffffffffa054f7b9>] btrfs_orphan_add+0x179/0x1a0 [btrfs]
When it comes to btrfs_lookup_dentry, we may set a snapshot's inode->i_ino
to BTRFS_EMPTY_SUBVOL_DIR_OBJECTID instead of BTRFS_FIRST_FREE_OBJECTID,
while the snapshot's location.objectid remains unchanged.
However, btrfs_ino() does not take this into account, and returns a wrong ino,
and causes the oops.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for-linus' of git://neil.brown.name/md:
md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.
md/raid1,10: Remove use-after-free bug in make_request.
md/raid10: unify handling of write completion.
Avoid dereferencing a 'request_queue' after last close.
On the last close of an 'md' device which as been stopped, the device
is destroyed and in particular the request_queue is freed. The free
is done in a separate thread so it might happen a short time later.
__blkdev_put calls bdev_inode_switch_bdi *after* ->release has been
called.
Since commit f758eeabeb
bdev_inode_switch_bdi will dereference the 'old' bdi, which lives
inside a request_queue, to get a spin lock. This causes the last
close on an md device to sometime take a spin_lock which lives in
freed memory - which results in an oops.
So move the called to bdev_inode_switch_bdi before the call to
->release.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Prior to 2.6.38 automount would not trigger on either stat(2) or
lstat(2) on the automount point.
After 2.6.38, with the introduction of the ->d_automount()
infrastructure, stat(2) and others would start triggering automount
while lstat(2), etc. still would not. This is a regression and a
userspace ABI change.
Problem originally reported here:
http://thread.gmane.org/gmane.linux.kernel.autofs/6098
It appears that there was an attempt at fixing various userspace tools
to not trigger the automount. But since the stat system call is
rather common it is impossible to "fix" all userspace.
This patch reverts the original behavior, which is to not trigger on
stat(2) and other symlink following syscalls.
[ It's not really clear what the right behavior is. Apparently Solaris
does the "automount on stat, leave alone on lstat". And some programs
can get unhappy when "stat+open+fstat" ends up giving a different
result from the fstat than from the initial stat.
But the change in 2.6.38 resulted in problems for some people, so
we're going back to old behavior. Maybe we can re-visit this
discussion at some future date - Linus ]
Reported-by: Leonardo Chiquitto <leonardo.lists@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Ian Kent <raven@themaw.net>
Cc: David Howells <dhowells@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* branch 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBIFS: not build debug messages with CONFIG_UBIFS_FS_DEBUG disabled
* branch 'linux-next' of git://git.infradead.org/ubi-2.6:
UBI: do not link debug messages when debugging is disabled
This make sure we don't end up reusing the unlinked inode object.
The ideal way is to use inode i_generation. But i_generation is
not available in userspace always.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Some of the flags are OS/arch dependent we add a 9p
protocol value which maps to asm-generic/fcntl.h values in Linux
Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
We should only update attributes that we can change on stat2inode.
Also do file type initialization in v9fs_init_inode.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
d_instantiate marks the dentry positive. So a parallel lookup and mkdir of
the directory can find dentry that doesn't have fid attached. This can result
in both the code path doing v9fs_fid_add which results in v9fs_dentry leak.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: fix ->write_inode return values
xfs: fix xfs_mark_inode_dirty during umount
xfs: deprecate the nodelaylog mount option
Currently we always redirty an inode that was attempted to be written out
synchronously but has been cleaned by an AIL pushed internall, which is
rather bogus. Fix that by doing the i_update_core check early on and
return 0 for it. Also include async calls for it, as doing any work for
those is just as pointless. While we're at it also fix the sign for the
EIO return in case of a filesystem shutdown, and fix the completely
non-sensical locking around xfs_log_inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
(cherry picked from commit 297db93bb74cf687510313eb235a7aec14d67e97)
Signed-off-by: Alex Elder <aelder@sgi.com>
During umount we do not add a dirty inode to the lru and wait for it to
become clean first, but force writeback of data and metadata with
I_WILL_FREE set. Currently there is no way for XFS to detect that the
inode has been redirtied for metadata operations, as we skip the
mark_inode_dirty call during teardown. Fix this by setting i_update_core
nanually in that case, so that the inode gets flushed during inode reclaim.
Alternatively we could enable calling mark_inode_dirty for inodes in
I_WILL_FREE state, and let the VFS dirty tracking handle this. I decided
against this as we will get better I/O patterns from reclaim compared to
the synchronous writeout in write_inode_now, and always marking the inode
dirty in some way from xfs_mark_inode_dirty is a better safetly net in
either case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
(cherry picked from commit da6742a5a4cc844a9982fdd936ddb537c0747856)
Signed-off-by: Alex Elder <aelder@sgi.com>
The i_mutex lock and flush_completed_IO() added by commit 2581fdc810
in ext4_evict_inode() causes lockdep complaining about potential
deadlock in several places. In most/all of these LOCKDEP complaints
it looks like it's a false positive, since many of the potential
circular locking cases can't take place by the time the
ext4_evict_inode() is called; but since at the very least it may mask
real problems, we need to address this.
This change removes the flush_completed_IO() and i_mutex lock in
ext4_evict_inode(). Instead, we take a different approach to resolve
the software lockup that commit 2581fdc810 intends to fix. Rather
than having ext4-dio-unwritten thread wait for grabing the i_mutex
lock of an inode, we use mutex_trylock() instead, and simply requeue
the work item if we fail to grab the inode's i_mutex lock.
This should speed up work queue processing in general and also
prevents the following deadlock scenario: During page fault,
shrink_icache_memory is called that in turn evicts another inode B.
Inode B has some pending io_end work so it calls ext4_ioend_wait()
that waits for inode B's i_ioend_count to become zero. However, inode
B's ioend work was queued behind some of inode A's ioend work on the
same cpu's ext4-dio-unwritten workqueue. As the ext4-dio-unwritten
thread on that cpu is processing inode A's ioend work, it tries to
grab inode A's i_mutex lock. Since the i_mutex lock of inode A is
still hold before the page fault happened, we enter a deadlock.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
