Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.
If the size of an xattr value is larger than will fit in a single
external block, then the xattr value will be saved into the body
of an external xattr inode.
The also helps support a larger number of xattr, since only the headers
will be stored in the in-inode space or the single external block.
The inode is referenced from the xattr header via "e_value_inum",
which was formerly "e_value_block", but that field was never used.
The e_value_size still contains the xattr size so that listing
xattrs does not need to look up the inode if the data is not accessed.
struct ext4_xattr_entry {
__u8 e_name_len; /* length of name */
__u8 e_name_index; /* attribute name index */
__le16 e_value_offs; /* offset in disk block of value */
__le32 e_value_inum; /* inode in which value is stored */
__le32 e_value_size; /* size of attribute value */
__le32 e_hash; /* hash value of name and value */
char e_name[0]; /* attribute name */
};
The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
holds a back-reference to the owning inode in its i_mtime field,
allowing the ext4/e2fsck to verify the correct inode is accessed.
[ Applied fix by Dan Carpenter to avoid freeing an ERR_PTR. ]
Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424
Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr
block when new references are made. However if dquot_initialize() hasn't
been called on an inode, request for charging is effectively ignored
because ext4_inode_info->i_dquot is not initialized yet.
Add dquot_initialize() to call paths that lead to ext4_xattr_block_set().
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
ext4_xattr_check_entry() was redundant with validation of the full xattr
entries list in ext4_xattr_check_entries(), which all callers also did.
ext4_xattr_check_entry() also didn't actually do correct validation;
specifically, it never checked that the value doesn't overlap the xattr
names, nor did it account for padding when checking whether the xattr
value overflows the available space. So remove it to eliminate any
potential confusion.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_xattr_check_names() actually validates both the xattr names and
values, not just the names. So rename it to ext4_xattr_check_entries()
to avoid confusion.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
There's no difference between ext4_xattr_list() and ext4_listxattr(), so
merge them together and just have ext4_listxattr(). Some years ago they
took different arguments, but that's no longer the case.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Constify static data in ext4 that is never (intentionally) modified so
that it is placed in .rodata and benefits from memory protection.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We must lock the xattr block before calculating or verifying the
checksum in order to avoid spurious checksum failures.
https://bugzilla.kernel.org/show_bug.cgi?id=193661
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
It was possible for an xattr value to have a very large size, which
would then pass validation on 32-bit architectures due to a pointer
wraparound. Fix this by validating the size in a way which avoids
pointer wraparound.
It was also possible that a value's size would fit in the available
space but its padded size would not. This would cause an out-of-bounds
memory write in ext4_xattr_set_entry when replacing the xattr value.
For example, if an xattr value of unpadded size 253 bytes went until the
very end of the inode or block, then using setxattr(2) to replace this
xattr's value with 256 bytes would cause a write to the 3 bytes past the
end of the inode or buffer, and the new xattr value would be incorrectly
truncated. Fix this by requiring that the padded size fit in the
available space rather than the unpadded size.
This patch shouldn't have any noticeable effect on
non-corrupted/non-malicious filesystems.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
With i_extra_isize equal to or close to the available space, it was
possible for us to read past the end of the inode when trying to detect
or validate in-inode xattrs. Fix this by checking for the needed extra
space first.
This patch shouldn't have any noticeable effect on
non-corrupted/non-malicious filesystems.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.
current_time() returns timestamps according to the
granularities set in the super_block.
The granularity check in ext4_current_time() to call
current_time() or CURRENT_TIME_SEC is not required.
Use current_time() directly to obtain timestamps
unconditionally, and remove ext4_current_time().
Quota files are assumed to be on the same filesystem.
Hence, use current_time() for these files as well.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Recent commits require line continuing printks to always use
pr_cont or KERN_CONT. Add these markings to a few more printks.
Miscellaneaous:
o Integrate the ea_idebug and ea_bdebug macros to use a single
call to printk(KERN_DEBUG instead of 3 separate printks
o Use the more common varargs macro style
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
It should be cpu_to_le32(), not le32_to_cpu(). No change in behavior.
Found with sparse, and this was the only endianness warning in fs/ext4/.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Move loop to make enough space in the inode from
ext4_expand_extra_isize_ea() into a separate function to make that
function smaller and better readable and also to avoid delaration of
variables inside a loop block.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
'start' variable is completely unused in ext4_expand_extra_isize_ea().
Variable 'first' is used only once in one place. So just remove them.
Variables 'entry' and 'last' are only really used later in the function
inside a loop. Move their declarations there.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Factor out function for moving xattrs from inode into external xattr
block from ext4_expand_extra_isize_ea(). That function is already quite
long and factoring out this rather standalone functionality helps
readability.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We were checking whether computed offsets do not exceed end of block in
ext4_xattr_shift_entries(). However this does not make sense since we
always only decrease offsets. So replace that assertion with a check
whether we really decrease xattrs value offsets.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently we don't support xattrs with e_value_block set. We don't allow
them to pass initial xattr check so there's no point for checking for
this later. Since these tests were untested, bugs were creeping in and
not all places which should have checked were checking e_value_block
anyway.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently we don't support xattrs with values stored out of line. Check
for that in ext4_xattr_check_names() to make sure we never work with
such xattrs since not all the code counts with that resulting is possible
weird corruption issues.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Conditions checking whether there is enough free space in an xattr block
and when xattr is large enough to make enough space in the inode forgot
to account for the fact that inode need not be completely filled up with
xattrs. Thus we could move unnecessarily many xattrs out of inode or
even falsely claim there is not enough space to expand the inode. We
also forgot to update the amount of free space in xattr block when moving
more xattrs and thus could decide to move too big xattr resulting in
unexpected failure.
Fix these problems by properly updating free space in the inode and
xattr block as we move xattrs. To simplify the math, avoid shifting
xattrs after removing each one xattr and instead just shift xattrs only
once there is enough free space in the inode.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When we need to move xattrs into external xattr block, we call
ext4_xattr_block_set() from ext4_expand_extra_isize_ea(). That may end
up calling ext4_mark_inode_dirty() again which will recurse back into
the inode expansion code leading to deadlocks.
Protect from recursion using EXT4_STATE_NO_EXPAND inode flag and move
its management into ext4_expand_extra_isize_ea() since its manipulation
is safe there (due to xattr_sem) from possible races with
ext4_xattr_set_handle() which plays with it as well.
CC: stable@vger.kernel.org # 4.4.x
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We did not count with the padding of xattr value when computing desired
shift of xattrs in the inode when expanding i_extra_isize. As a result
we could create unaligned start of inline xattrs. Account for alignment
properly.
CC: stable@vger.kernel.org # 4.4.x-
Signed-off-by: Jan Kara <jack@suse.cz>
When multiple xattrs need to be moved out of inode, we did not properly
recompute total size of xattr headers in the inode and the new header
position. Thus when moving the second and further xattr we asked
ext4_xattr_shift_entries() to move too much and from the wrong place,
resulting in possible xattr value corruption or general memory
corruption.
CC: stable@vger.kernel.org # 4.4.x
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The code in ext4_expand_extra_isize_ea() treated new_extra_isize
argument sometimes as the desired target i_extra_isize and sometimes as
the amount by which we need to grow current i_extra_isize. These happen
to coincide when i_extra_isize is 0 which used to be the common case and
so nobody noticed this until recently when we added i_projid to the
inode and so i_extra_isize now needs to grow from 28 to 32 bytes.
The result of these bugs was that we sometimes unnecessarily decided to
move xattrs out of inode even if there was enough space and we often
ended up corrupting in-inode xattrs because arguments to
ext4_xattr_shift_entries() were just wrong. This could demonstrate
itself as BUG_ON in ext4_xattr_shift_entries() triggering.
Fix the problem by introducing new isize_diff variable and use it where
appropriate.
CC: stable@vger.kernel.org # 4.4.x
Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We temporally change checksum fields in buffers of some types of
metadata into '0' for verifying the checksum values. By doing this
without locking the buffer, some metadata's checksums, which are
being committed or written back to the storage, could be damaged.
In our test, several metadata blocks were found with damaged metadata
checksum value during recovery process. When we only verify the
checksum value, we have to avoid modifying checksum fields directly.
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
We aren't checking to see if the in-inode extended attribute is
corrupted before we try to expand the inode's extra isize fields.
This can lead to potential crashes caused by the BUG_ON() check in
ext4_xattr_shift_entries().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
To reduce amount of damage caused by single bad block, we limit number
of inodes sharing an xattr block to 1024. Thus there can be more xattr
blocks with the same contents when there are lots of files with the same
extended attributes. These xattr blocks naturally result in hash
collisions and can form long hash chains and we unnecessarily check each
such block only to find out we cannot use it because it is already
shared by too many inodes.
Add a reusable flag to cache entries which is cleared when a cache entry
has reached its maximum refcount. Cache entries which are not marked
reusable are skipped by mb_cache_entry_find_{first,next}. This
significantly speeds up mbcache when there are many same xattr blocks.
For example for xattr-bench with 5 values and each process handling
20000 files, the run for 64 processes is 25x faster with this patch.
Even for 8 processes the speedup is almost 3x. We have also verified
that for situations where there is only one xattr block of each kind,
the patch doesn't have a measurable cost.
[JK: Remove handling of setting the same value since it is not needed
anymore, check for races in e_reusable setting, improve changelog,
add measurements]
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When someone tried to set xattr to the same value (i.e., not changing
anything) we did all the work of removing original xattr, possibly
breaking references to shared xattr block, inserting new xattr, and
merging xattr blocks again. Since this is not so rare operation and it
is relatively cheap for us to detect this case, check for this and
shortcut xattr setting in that case.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since old mbcache code is gone, let's rename new code to mbcache since
number 2 is now meaningless. This is just a mechanical replacement.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The conversion is generally straightforward. The only tricky part is
that xattr block corresponding to found mbcache entry can get freed
before we get buffer lock for that block. So we have to check whether
the entry is still valid after getting buffer lock.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
Change the list operation to only return whether or not an attribute
should be listed. Copying the attribute names into the buffer is moved
to the callers.
Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example. In some oprations, it would be useful to also have
access to the handler prefix. To allow that, pass a pointer to the handler
to operations instead of the flags value alone.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Create separate predicate functions to test/set/clear feature flags,
thereby replacing the wordy old macros. Furthermore, clean out the
places where we open-coded feature tests.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Instead of overloading EIO for CRC errors and corrupt structures,
return the same error codes that XFS returns for the same issues.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In this if statement, the previous condition is useless, the later one
has covered it.
Signed-off-by: Weiyuan <weiyuan.wei@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Remove unused header files and header files which are included in
ext4.h.
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Besides the fact that this replacement improves code readability
it also protects from errors caused direct EXT4_S(sb)->s_es manipulation
which may result attempt to use uninitialized csum machinery.
#Testcase_BEGIN
IMG=/dev/ram0
MNT=/mnt
mkfs.ext4 $IMG
mount $IMG $MNT
#Enable feature directly on disk, on mounted fs
tune2fs -O metadata_csum $IMG
# Provoke metadata update, likey result in OOPS
touch $MNT/test
umount $MNT
#Testcase_END
# Replacement script
@@
expression E;
@@
- EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
+ ext4_has_metadata_csum(E)
https://bugzilla.kernel.org/show_bug.cgi?id=82201
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
When loading extended attributes, check each entry's value offset to
make sure it doesn't collide with the entries.
Without this check it is easy to crash the kernel by mounting a
malicious FS containing a file with an EA wherein e_value_offs = 0 and
e_value_size > 0 and then deleting the EA, which corrupts the name
list.
(See the f_ea_value_crash test's FS image in e2fsprogs for an example.)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented
because it was too hard to make sure the mballoc and get_block flags
could be reliably passed down through all of the codepaths that end up
calling ext4_mb_new_blocks().
Since then, we have mb_flags passed down through most of the code
paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky
as it used to.
This commit plumbs in the last of what is required, and then adds a
WARN_ON check to make sure we haven't missed anything. If this passes
a full regression test run, we can then drop
EXT4_STATE_DELALLOC_RESERVED.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
In ext4_xattr_set_handle() we have checked the xattr name's length. So
we should also check it in ext4_xattr_get() to avoid unneeded lookup
caused by invalid name.
Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When heavily exercising xattr code the assertion that
jbd2_journal_dirty_metadata() shouldn't return error was triggered:
WARNING: at /srv/autobuild-ceph/gitbuilder.git/build/fs/jbd2/transaction.c:1237
jbd2_journal_dirty_metadata+0x1ba/0x260()
CPU: 0 PID: 8877 Comm: ceph-osd Tainted: G W 3.10.0-ceph-00049-g68d04c9 #1
Hardware name: Dell Inc. PowerEdge R410/01V648, BIOS 1.6.3 02/07/2011
ffffffff81a1d3c8 ffff880214469928 ffffffff816311b0 ffff880214469968
ffffffff8103fae0 ffff880214469958 ffff880170a9dc30 ffff8802240fbe80
0000000000000000 ffff88020b366000 ffff8802256e7510 ffff880214469978
Call Trace:
[<ffffffff816311b0>] dump_stack+0x19/0x1b
[<ffffffff8103fae0>] warn_slowpath_common+0x70/0xa0
[<ffffffff8103fb2a>] warn_slowpath_null+0x1a/0x20
[<ffffffff81267c2a>] jbd2_journal_dirty_metadata+0x1ba/0x260
[<ffffffff81245093>] __ext4_handle_dirty_metadata+0xa3/0x140
[<ffffffff812561f3>] ext4_xattr_release_block+0x103/0x1f0
[<ffffffff81256680>] ext4_xattr_block_set+0x1e0/0x910
[<ffffffff8125795b>] ext4_xattr_set_handle+0x38b/0x4a0
[<ffffffff810a319d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff81257b32>] ext4_xattr_set+0xc2/0x140
[<ffffffff81258547>] ext4_xattr_user_set+0x47/0x50
[<ffffffff811935ce>] generic_setxattr+0x6e/0x90
[<ffffffff81193ecb>] __vfs_setxattr_noperm+0x7b/0x1c0
[<ffffffff811940d4>] vfs_setxattr+0xc4/0xd0
[<ffffffff8119421e>] setxattr+0x13e/0x1e0
[<ffffffff811719c7>] ? __sb_start_write+0xe7/0x1b0
[<ffffffff8118f2e8>] ? mnt_want_write_file+0x28/0x60
[<ffffffff8118c65c>] ? fget_light+0x3c/0x130
[<ffffffff8118f2e8>] ? mnt_want_write_file+0x28/0x60
[<ffffffff8118f1f8>] ? __mnt_want_write+0x58/0x70
[<ffffffff811946be>] SyS_fsetxattr+0xbe/0x100
[<ffffffff816407c2>] system_call_fastpath+0x16/0x1b
The reason for the warning is that buffer_head passed into
jbd2_journal_dirty_metadata() didn't have journal_head attached. This is
caused by the following race of two ext4_xattr_release_block() calls:
CPU1 CPU2
ext4_xattr_release_block() ext4_xattr_release_block()
lock_buffer(bh);
/* False */
if (BHDR(bh)->h_refcount == cpu_to_le32(1))
} else {
le32_add_cpu(&BHDR(bh)->h_refcount, -1);
unlock_buffer(bh);
lock_buffer(bh);
/* True */
if (BHDR(bh)->h_refcount == cpu_to_le32(1))
get_bh(bh);
ext4_free_blocks()
...
jbd2_journal_forget()
jbd2_journal_unfile_buffer()
-> JH is gone
error = ext4_handle_dirty_xattr_block(handle, inode, bh);
-> triggers the warning
We fix the problem by moving ext4_handle_dirty_xattr_block() under the
buffer lock. Sadly this cannot be done in nojournal mode as that
function can call sync_dirty_buffer() which would deadlock. Luckily in
nojournal mode the race is harmless (we only dirty already freed buffer)
and thus for nojournal mode we leave the dirtying outside of the buffer
lock.
Reported-by: Sage Weil <sage@inktank.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
This patch adds new interfaces to create and destory cache,
ext4_xattr_create_cache() and ext4_xattr_destroy_cache(), and remove
the cache creation and destory calls from ex4_init_xattr() and
ext4_exitxattr() in fs/ext4/xattr.c.
fs/ext4/super.c has been changed so that when a filesystem is mounted
a cache is allocated and attched to its ext4_sb_info structure.
fs/mbcache.c has been changed so that only one slab allocator is
allocated and used by all mbcache structures.
Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
