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Fix CONFIG_LOCKDEP=n build, because asserts I put in to ensure we
aren't overrunning lockdep subclasses in commit 0952c81 ("xfs:
clean up inode lockdep annotations") use a define that doesn't
exist when CONFIG_LOCKDEP=n
Only check the subclass limits when lockdep is actually enabled.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Filesystems are responsible to manage file coherency between the page
cache and direct I/O. The generic dio code flushes dirty pages over the
range of a dio to ensure that the dio read or a future buffered read
returns the correct data. XFS has generally followed this pattern,
though traditionally has flushed and invalidated the range from the
start of the I/O all the way to the end of the file. This changed after
the following commit:
7d4ea3ce xfs: use ranged writeback and invalidation for direct IO
... as the full file flush was no longer necessary to deal with the
strange post-eof delalloc issues that were since fixed. Unfortunately,
we have since received complaints about performance degradation due to
the increased exclusive iolock cycles (which locks out parallel dio
submission) that occur when a file has cached pages. This does not occur
on filesystems that use the generic code as it also does not incorporate
locking.
The exclusive iolock is acquired any time the inode mapping has cached
pages, regardless of whether they reside in the range of the I/O or not.
If not, the flush/inval calls do no work and the lock was cycled for no
reason.
Under consideration of the cost of the exclusive iolock, update the dio
read and write handlers to flush and invalidate the entire mapping when
cached pages exist. In most cases, this increases the cost of the
initial flush sequence but eliminates the need for further lock cycles
and flushes so long as the workload does not actively mix direct and
buffered I/O. This also more closely matches historical behavior and
performance characteristics that users have come to expect.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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struct xfs_attr_leafblock contains 'entries' array which is declared
with size 1 altough it can in fact contain much more entries. Since this
array is followed by further struct members, gcc (at least in version
4.8.3) thinks that the array has the fixed size of 1 element and thus
may optimize away all accesses beyond the end of array resulting in
non-working code. This problem was only observed with userspace code in
xfsprogs, however it's better to be safe in kernel as well and have
matching kernel and xfsprogs definitions.
cc: <stable@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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In the dir3 data block readahead function, use the regular read
verifier to check the block's CRC and spot-check the block contents
instead of directly calling only the spot-checking routine. This
prevents corrupted directory data blocks from being read into the
kernel, which can lead to garbage ls output and directory loops (if
say one of the entries contains slashes and other junk).
cc: <stable@vger.kernel.org> # 3.12 - 4.2
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The recent change to the readdir locking made in 40194ec ("xfs:
reinstate the ilock in xfs_readdir") for CXFS directory sanity was
probably the wrong thing to do. Deep in the readdir code we
can take page faults in the filldir callback, and so taking a page
fault while holding an inode ilock creates a new set of locking
issues that lockdep warns all over the place about.
The locking order for regular inodes w.r.t. page faults is io_lock
-> pagefault -> mmap_sem -> ilock. The directory readdir code now
triggers ilock -> page fault -> mmap_sem. While we cannot deadlock
at this point, it inverts all the locking patterns that lockdep
normally sees on XFS inodes, and so triggers lockdep. We worked
around this with commit 93a8614 ("xfs: fix directory inode iolock
lockdep false positive"), but that then just moved the lockdep
warning to deeper in the page fault path and triggered on security
inode locks. Fixing the shmem issue there just moved the lockdep
reports somewhere else, and now we are getting false positives from
filesystem freezing annotations getting confused.
Further, if we enter memory reclaim in a readdir path, we now get
lockdep warning about potential deadlocks because the ilock is held
when we enter reclaim. This, again, is different to a regular file
in that we never allow memory reclaim to run while holding the ilock
for regular files. Hence lockdep now throws
ilock->kmalloc->reclaim->ilock warnings.
Basically, the problem is that the ilock is being used to protect
the directory data and the inode metadata, whereas for a regular
file the iolock protects the data and the ilock protects the
metadata. From the VFS perspective, the i_mutex serialises all
accesses to the directory data, and so not holding the ilock for
readdir doesn't matter. The issue is that CXFS doesn't access
directory data via the VFS, so it has no "data serialisaton"
mechanism. Hence we need to hold the IOLOCK in the correct places to
provide this low level directory data access serialisation.
The ilock can then be used just when the extent list needs to be
read, just like we do for regular files. The directory modification
code can take the iolock exclusive when the ilock is also taken,
and this then ensures that readdir is correct excluded while
modifications are in progress.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Lockdep annotations are a maintenance nightmare. Locking has to be
modified to suit the limitations of the annotations, and we're
always having to fix the annotations because they are unable to
express the complexity of locking heirarchies correctly.
So, next up, we've got more issues with lockdep annotations for
inode locking w.r.t. XFS_LOCK_PARENT:
- lockdep classes are exclusive and can't be ORed together
to form new classes.
- IOLOCK needs multiple PARENT subclasses to express the
changes needed for the readdir locking rework needed to
stop the endless flow of lockdep false positives involving
readdir calling filldir under the ILOCK.
- there are only 8 unique lockdep subclasses available,
so we can't create a generic solution.
IOWs we need to treat the 3-bit space available to each lock type
differently:
- IOLOCK uses xfs_lock_two_inodes(), so needs:
- at least 2 IOLOCK subclasses
- at least 2 IOLOCK_PARENT subclasses
- MMAPLOCK uses xfs_lock_two_inodes(), so needs:
- at least 2 MMAPLOCK subclasses
- ILOCK uses xfs_lock_inodes with up to 5 inodes, so needs:
- at least 5 ILOCK subclasses
- one ILOCK_PARENT subclass
- one RTBITMAP subclass
- one RTSUM subclass
For the IOLOCK, split the space into two sets of subclasses.
For the MMAPLOCK, just use half the space for the one subclass to
match the non-parent lock classes of the IOLOCK.
For the ILOCK, use 0-4 as the ILOCK subclasses, 5-7 for the
remaining individual subclasses.
Because they are now all different, modify xfs_lock_inumorder() to
handle the nested subclasses, and to assert fail if passed an
invalid subclass. Further, annotate xfs_lock_inodes() to assert fail
if an invalid combination of lock primitives and inode counts are
passed that would result in a lockdep subclass annotation overflow.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The node directory lookup code uses a state structure that tracks the
path of buffers used to search for the hash of a filename through the
leaf blocks. When the lookup encounters a block that ends with the
requested hash, but the entry has not yet been found, it must shift over
to the next block and continue looking for the entry (i.e., duplicate
hashes could continue over into the next block). This shift mechanism
involves walking back up and down the state structure, replacing buffers
at the appropriate btree levels as necessary.
When a buffer is replaced, the old buffer is released and the new buffer
read into the active slot in the path structure. Because the buffer is
read directly into the path slot, a buffer read failure can result in
setting a NULL buffer pointer in an active slot. This throws off the
state cleanup code in xfs_dir2_node_lookup(), which expects to release a
buffer from each active slot. Instead, a BUG occurs due to a NULL
pointer dereference:
BUG: unable to handle kernel NULL pointer dereference at 00000000000001e8
IP: [<ffffffffa0585063>] xfs_trans_brelse+0x2a3/0x3c0 [xfs]
...
RIP: 0010:[<ffffffffa0585063>] [<ffffffffa0585063>] xfs_trans_brelse+0x2a3/0x3c0 [xfs]
...
Call Trace:
[<ffffffffa05250c6>] xfs_dir2_node_lookup+0xa6/0x2c0 [xfs]
[<ffffffffa0519f7c>] xfs_dir_lookup+0x1ac/0x1c0 [xfs]
[<ffffffffa055d0e1>] xfs_lookup+0x91/0x290 [xfs]
[<ffffffffa05580b3>] xfs_vn_lookup+0x73/0xb0 [xfs]
[<ffffffff8122de8d>] lookup_real+0x1d/0x50
[<ffffffff8123330e>] path_openat+0x91e/0x1490
[<ffffffff81235079>] do_filp_open+0x89/0x100
...
This has been reproduced via a parallel fsstress and filesystem shutdown
workload in a loop. The shutdown triggers the read error in the
aforementioned codepath and causes the BUG in xfs_dir2_node_lookup().
Update xfs_da3_path_shift() to update the active path slot atomically
with respect to the caller when a buffer is replaced. This ensures that
the caller always sees the old or new buffer in the slot and prevents
the NULL pointer dereference.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The sparse inodes feature is currently considered experimental. We warn
at mount time from xfs_mount_validate_sb(). This function is part of the
superblock verifier codepath, however, which means it could be invoked
repeatedly on superblock reads or writes. This is currently only
noticeable from userspace, where mkfs produces multiple warnings at
format time.
As mkfs warnings were not the intent of this change, relocate the mount
time warning to xfs_fs_fill_super(), which is only invoked once and only
in kernel space.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Once the sb_uuid is changed, the wrong uuid is stamped into new
dquots on disk. Found by inspection, verified by generic/219.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Now that sb_uuid can be changed by the user, we cannot use this to
validate the metadata blocks being recovered belong to this
filesystem. We must check against the sb_meta_uuid as that will
remain unchanged.
There is a complication in this code - the superblock itself. We can
not check the sb_meta_uuid unconditionally, as that may not be set
on disk. Hence we must verify the superblock sb_uuid matches between
the log record and the in-core superblock.
Found by inspection after the previous two problems were found.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Adding this simple change to xfstests:common/rc::_scratch_mkfs_xfs:
+ if [ $mkfs_status -eq 0 ]; then
+ xfs_admin -U generate $SCRATCH_DEV > /dev/null
+ fi
triggers all sorts of errors in xfstests. xfs/104 is an example,
where growfs fails with a UUID mismatch corruption detected by
xfs_agf_write_verify() when trying to write the first new AG
headers.
Fix this problem by making sure we copy the sb_meta_uuid into new
metadata written by growfs.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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After changing the UUID on a v5 filesystem, xfstests fails
immediately on a debug kernel with:
XFS: Assertion failed: uuid_equal(&ip->i_d.di_uuid, &mp->m_sb.sb_uuid), file: fs/xfs/xfs_inode.c, line: 799
This needs to check against the sb_meta_uuid, not the user visible
UUID that was changed.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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It's entirely possible for userspace to ask for an xattr which
does not exist.
Normally, there is no problem whatsoever when we ask for such
a thing, but when we look at an obfuscated metadump image
on a debug kernel with selinux, we trip over this ASSERT in
xfs_da3_path_shift():
*result = -ENOENT; /* we're out of our tree */
ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
It (more or less) only shows up in the above scenario, because
xfs_metadump obfuscates attr names, but chooses names which
keep the same hash value - and xfs_da3_node_lookup_int does:
if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
(blk->hashval == args->hashval)) {
error = xfs_da3_path_shift(state, &state->path, 1, 1,
&retval);
IOWS, we only get down to the xfs_da3_path_shift() ASSERT
if we are looking for an xattr which doesn't exist, but we
find xattrs on disk which have the same hash, and so might be
a hash collision, so we try the path shift. When *that*
fails to find what we're looking for, we hit the assert about
XFS_DA_OP_OKNOENT.
Simply setting XFS_DA_OP_OKNOENT in xfs_attr_get solves this
rather corner-case problem with no ill side effects. It's
fine for an attr name lookup to fail.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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If a failure occurs after the bmap free list is populated and before
xfs_bmap_finish() completes successfully (which returns a partial
list on failure), the bmap free list must be cancelled. Otherwise,
the extent items on the list are never freed and a memory leak
occurs.
Several random error paths throughout the code suffer this problem.
Fix these up such that xfs_bmap_cancel() is always called on error.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Several areas of code duplicate a pattern where we take the AIL lock,
check whether an item is in the AIL and remove it if so. Create a new
helper for this pattern and use it where appropriate.
Signed-off-by: Brian Foster <bfoster@redhat.com>
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The btree cursor cleanup function takes an error parameter that
affects how buffers are released from the cursor. All buffers are
released in the event of error. Several callers do not specify the
XFS_BTREE_ERROR flag in the event of error, however. This can cause
buffers to hang around locked or with an elevated hold count and
thus lead to umount hangs in the event of errors.
Fix up the xfs_btree_del_cursor() callers to pass XFS_BTREE_ERROR if
the cursor is being torn down due to error.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The root inode is read as part of the xfs_mountfs() sequence and the
reference is dropped in the event of failure after we grab the
inode. The reference drop doesn't necessarily free the inode,
however. It marks it for reclaim and potentially kicks off the
reclaim workqueue. The workqueue is destroyed further up the error
path, which means we are subject to crash if the workqueue job runs
after this point or a memory leak which is identified if the
xfs_inode_zone is destroyed (e.g., on module removal). Both of these
outcomes are reproducible via manual instrumentation of a mount
error after the root inode xfs_iget() call in xfs_mountfs().
Update the xfs_mountfs() error path to cancel any potential reclaim
work items and to run a synchronous inode reclaim if the root inode
is marked for reclaim. This ensures that no jobs remain on the queue
before it is destroyed and that the root inode is freed before the
reclaim mechanism is torn down.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The first 4 bytes of every basic block in the physical log is stamped
with the current lsn. To support this mechanism, the log record header
(first block of each new log record) contains space for the original
first byte of each log record block before it is replaced with the lsn.
The log record header has space for 32k worth of blocks. The version 2
log adds new extended record headers for each additional 32k worth of
blocks beyond what is supported by the record header.
The log record checksum incorporates the log record header, the extended
headers and the record payload. xlog_cksum() checksums the extended
headers based on log->l_iclog_heads, which specifies the number of
extended headers in a log record based on the log buffer size mount
option. The log buffer size is variable, however, and thus means the
checksum can be calculated differently based on how a filesystem is
mounted. This is problematic if a filesystem crashes and recovery occurs
on a subsequent mount using a different log buffer size. For example,
crash an active filesystem that is mounted with the default (32k)
logbsize, attempt remount/recovery using '-o logbsize=64k' and the mount
fails on or warns about log checksum failures.
To avoid this problem, update xlog_cksum() to calculate the checksum
based on the size of the log buffer according to the log record. The
size is already included in the h_size field of the log record header
and thus is available at log recovery time. Extended log record headers
are also only written when the log record is large enough to require
them. This makes checksum calculation of log records consistent with the
extended record header mechanism as well as how on-disk records are
checksummed with various log buffer size mount options.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Inode cluster buffers are invalidated and cancelled when inode chunks
are freed to notify log recovery that previous logged updates to the
metadata buffer should be skipped. This ensures that log recovery does
not overwrite buffers that might have already been reused.
On v4 filesystems, inode chunk allocation and inode updates are logged
via the cluster buffers and thus cancellation is easily detected via
buffer cancellation items. v5 filesystems use the new icreate
transaction, which uses logical logging and ordered buffers to log a
full inode chunk allocation at once. The resulting icreate item often
spans multiple inode cluster buffers.
Log recovery checks for cancelled buffers when processing icreate log
items, but it has a couple problems. First, it uses the full length of
the inode chunk rather than the cluster size. Second, it uses the length
in FSB units rather than BB units. Either of these problems prevent
icreate recovery from identifying cancelled buffers and thus inode
initialization proceeds unconditionally.
Update xlog_recover_do_icreate_pass2() to iterate the icreate range in
cluster sized increments and check each increment for cancellation.
Since icreate is currently only used for the minimum atomic inode chunk
allocation, we expect that either all or none of the buffers will be
cancelled. Cancel the icreate if at least one buffer is cancelled to
avoid making a bad situation worse by initializing a partial inode
chunk, but detect such anomalies and warn the user.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Various log items have recovery tracepoints to identify whether a
particular log item is recovered or cancelled. Add the equivalent
tracepoints for the icreate transaction.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Log recovery occurs in two phases at mount time. In the first phase,
EFIs and EFDs are processed and potentially cancelled out. EFIs without
EFD objects are inserted into the AIL for processing and recovery in the
second phase. xfs_mountfs() runs various other operations between the
phases and is thus subject to failure. If failure occurs after the first
phase but before the second, pending EFIs sit on the AIL, pin it and
cause the mount to hang.
Update the mount sequence to ensure that pending EFIs are cancelled in
the event of failure. Add a recovery cancellation mechanism to iterate
the AIL and cancel all EFI items when requested. Plumb cancellation
support through the log mount finish helper and update xfs_mountfs() to
invoke cancellation in the event of failure after recovery has started.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The EFI is initialized with a reference count of 2. One for the EFI to
ensure the item makes it to the AIL and one for the subsequently created
EFD to release the EFI once the EFD is committed. Log recovery uses the
EFI in a similar manner, but implements a hack to remove both references
in one call once the EFD is handled.
Update log recovery to use EFI reference counting in a manner consistent
with the log. When an EFI is encountered during recovery, an EFI item is
allocated and inserted to the AIL directly. Since the EFI reference is
typically dropped when the EFI is unpinned and this is analogous with
AIL insertion, drop the EFI reference at this point.
When a corresponding EFD is encountered in the log, this indicates that
the extents were freed, no processing is required and the EFI can be
dropped. Update xlog_recover_efd_pass2() to simply drop the EFD
reference at this point rather than open code the AIL removal and EFI
free.
Remaining EFIs (i.e., with no corresponding EFD) are processed in
xlog_recover_finish(). An EFD transaction is allocated and the extents
are freed, which transfers ownership of the EFI reference to the EFD
item in the log.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Log recovery attempts to free extents with leftover EFIs in the AIL
after initial processing. If the extent free fails (e.g., due to
unrelated fs corruption), the transaction is cancelled, though it
might not be dirtied at the time. If this is the case, the EFD does
not abort and thus does not release the EFI. This can lead to hangs
as the EFI pins the AIL.
Update xlog_recover_process_efi() to log the EFD in the transaction
before xfs_free_extent() errors are handled to ensure the
transaction is dirty, aborts the EFD and releases the EFI on error.
Since this is a requirement for EFD processing (and consistent with
xfs_bmap_finish()), update the EFD logging helper to do the extent
free and unconditionally log the EFD. This encodes the required EFD
logging behavior into the helper and reduces the likelihood of
errors down the road.
[dchinner: re-add xfs_alloc.h to xfs_log_recover.c to fix build
failure.]
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Freeing an extent in XFS involves logging an EFI (extent free
intention), freeing the actual extent, and logging an EFD (extent
free done). The EFI object is created with a reference count of 2:
one for the current transaction and one for the subsequently created
EFD. Under normal circumstances, the first reference is dropped when
the EFI is unpinned and the second reference is dropped when the EFD
is committed to the on-disk log.
In event of errors or filesystem shutdown, there are various
potential cleanup scenarios depending on the state of the EFI/EFD.
The cleanup scenarios are confusing and racy, as demonstrated by the
following test sequence:
# mount $dev $mnt
# fsstress -d $mnt -n 99999 -p 16 -z -f fallocate=1 \
-f punch=1 -f creat=1 -f unlink=1 &
# sleep 5
# killall -9 fsstress; wait
# godown -f $mnt
# umount
... in which the final umount can hang due to the AIL being pinned
indefinitely by one or more EFI items. This can occur due to several
conditions. For example, if the shutdown occurs after the EFI is
committed to the on-disk log and the EFD committed to the CIL, but
before the EFD committed to the log, the EFD iop_committed() abort
handler does not drop its reference to the EFI. Alternatively,
manual error injection in the xfs_bmap_finish() codepath shows that
if an error occurs after the EFI transaction is committed but before
the EFD is constructed and logged, the EFI is never released from
the AIL.
Update the EFI/EFD item handling code to use a more straightforward
and reliable approach to error handling. If an error occurs after
the EFI transaction is committed and before the EFD is constructed,
release the EFI explicitly from xfs_bmap_finish(). If the EFI
transaction is cancelled, release the EFI in the unlock handler.
Once the EFD is constructed, it is responsible for releasing the EFI
under any circumstances (including whether the EFI item aborts due
to log I/O error). Update the EFD item handlers to release the EFI
if the transaction is cancelled or aborts due to log I/O error.
Finally, update xfs_bmap_finish() to log at least one EFD extent to
the transaction before xfs_free_extent() errors are handled to
ensure the transaction is dirty and EFD item error handling is
triggered.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Some callers need to make error handling decisions based on whether
the current transaction successfully committed or not. Rename
xfs_trans_roll(), add a new parameter and provide a wrapper to
preserve existing callers.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Release of the EFI either occurs based on the reference count or the
extent count. The extent count used is either the count tracked in
the EFI or EFD, depending on the particular situation. In either
case, the count is initialized to the final value and thus always
matches the current efi_next_extent value once the EFI is completely
constructed. For example, the EFI extent count is increased as the
extents are logged in xfs_bmap_finish() and the full free list is
always completely processed. Therefore, the count is guaranteed to
be complete once the EFI transaction is committed. The EFD uses the
efd_nextents counter to release the EFI. This counter is initialized
to the count of the EFI when the EFD is created. Thus the EFD, as
currently used, has no concept of partial EFI release based on
extent count.
Given that the EFI extent count is always released in whole, use of
the extent count for reference counting is unnecessary. Remove this
level of the API and release the EFI based on the core reference
count. The efi_next_extent counter remains because it is still used
to track the slot to log the next extent to free.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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This adds a new superblock field, sb_meta_uuid. If set, along with
a new incompat flag, the code will use that field on a V5 filesystem
to compare to metadata UUIDs, which allows us to change the user-
visible UUID at will. Userspace handles the setting and clearing
of the incompat flag as appropriate, as the UUID gets changed; i.e.
setting the user-visible UUID back to the original UUID (as stored in
the new field) will remove the incompatible feature flag.
If the incompat flag is not set, this copies the user-visible UUID into
into the meta_uuid slot in memory when the superblock is read from disk;
the meta_uuid field is not written back to disk in this case.
The remainder of this patch simply switches verifiers, initializers,
etc to use the new sb_meta_uuid field.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The header side of xfs_bit.c is already in libxfs, and the sparse
inode code requires the xfs_next_bit() function so pull in the
xfs_bit.c file so that a sparse inode enabled libxfs compiles
cleanly in userspace.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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xfs_create() and xfs_create_tmpfile() have useless jumps to identical
labels. Simplify them.
Signed-off-by: Jan Kara <jack@suse.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The second and subsequent lines of multi-line logging messages
are not prefixed with the same information as the first line.
Separate messages with newlines into multiple calls to ensure
consistent prefixing and allow easier grep use.
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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When log recovery hits a new transaction, it copies the transaction
header from the expected location in the log to the in-core structure
using the length from the op record header. This length is validated to
ensure it doesn't exceed the length of the record, but not against the
expected size of a transaction header (and thus the size of the in-core
structure). If the on-disk length is corrupted, the associated memcpy()
can overflow, write to unrelated memory and lead to crashes. This has
been reproduced via filesystem fuzzing.
The code currently handles the possibility that the transaction header
is split across two op records. Neither instance accounts for corruption
where the op record length might be larger than the in-core transaction
header. Update both sites to detect such corruption, warn and return an
error from log recovery. Also add some comments and assert that if the
record is split, the copy of the second portion is less than a full
header. Otherwise, this suggests the copy of the second portion could
have overwritten bits from the first and thus that something could be
wrong.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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We have seen somewhat rare reports of the following assert from
xlog_cil_push_background() failing during ltp tests or somewhat
innocuous desktop root fs workloads (e.g., virt operations, initramfs
construction):
ASSERT(!list_empty(&cil->xc_cil));
The reasoning behind the assert is that the transaction has inserted
items to the CIL and hit background push codepath all with
cil->xc_ctx_lock held for reading. This locks out background commit from
emptying the CIL, which acquires the lock for writing. Therefore, the
reasoning is that the items previously inserted in the CIL should still
be present.
The cil->xc_ctx_lock read lock is not sufficient to protect the xc_cil
list, however, due to how CIL insertion is handled.
xlog_cil_insert_items() inserts and reorders the dirty transaction items
to the tail of the CIL under xc_cil_lock. It uses list_move_tail() to
achieve insertion and reordering in the same block of code. This
function removes and reinserts an item to the tail of the list. If a
transaction commits an item that was already logged and thus already
resides in the CIL, and said item is the sole item on the list, the
removal and reinsertion creates a temporary state where the list is
actually empty.
This state is not valid and thus should never be observed by concurrent
transaction commit-side checks in the circumstances outlined above. We
do not want to acquire the xc_cil_lock in all of these instances as it
was previously removed and replaced with a separate push lock for
performance reasons. Therefore, close any races with list_empty() on the
insertion side by ensuring that the list is never in a transient empty
state.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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xfs_bunmapi() doesn't care what type of extent is being freed and
does not look at the XFS_BMAPI_METADATA flag at all. As such we can
remove the XFS_BMAPI_METADATA from all callers that use it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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We don't log remote attribute contents, and instead write them
synchronously before we commit the block allocation and attribute
tree update transaction. As a result we are writing to the allocated
space before the allcoation has been made permanent.
As a result, we cannot consider this allocation to be a metadata
allocation. Metadata allocation can take blocks from the free list
and so reuse them before the transaction that freed the block is
committed to disk. This behaviour is perfectly fine for journalled
metadata changes as log recovery will ensure the free operation is
replayed before the overwrite, but for remote attribute writes this
is not the case.
Hence we have to consider the remote attribute blocks to contain
data and allocate accordingly. We do this by dropping the
XFS_BMAPI_METADATA flag from the block allocation. This means the
allocation will not use blocks that are on the busy list without
first ensuring that the freeing transaction has been committed to
disk and the blocks removed from the busy list. This ensures we will
never overwrite a freed block without first ensuring that it is
really free.
cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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In recent testing, a system that crashed failed log recovery on
restart with a bad symlink buffer magic number:
XFS (vda): Starting recovery (logdev: internal)
XFS (vda): Bad symlink block magic!
XFS: Assertion failed: 0, file: fs/xfs/xfs_log_recover.c, line: 2060
On examination of the log via xfs_logprint, none of the symlink
buffers in the log had a bad magic number, nor were any other types
of buffer log format headers mis-identified as symlink buffers.
Tracing was used to find the buffer the kernel was tripping over,
and xfs_db identified it's contents as:
000: 5841524d 00000000 00000346 64d82b48 8983e692 d71e4680 a5f49e2c b317576e
020: 00000000 00602038 00000000 006034ce d0020000 00000000 4d4d4d4d 4d4d4d4d
040: 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d
060: 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d
.....
This is a remote attribute buffer, which are notable in that they
are not logged but are instead written synchronously by the remote
attribute code so that they exist on disk before the attribute
transactions are committed to the journal.
The above remote attribute block has an invalid LSN in it - cycle
0xd002000, block 0 - which means when log recovery comes along to
determine if the transaction that writes to the underlying block
should be replayed, it sees a block that has a future LSN and so
does not replay the buffer data in the transaction. Instead, it
validates the buffer magic number and attaches the buffer verifier
to it. It is this buffer magic number check that is failing in the
above assert, indicating that we skipped replay due to the LSN of
the underlying buffer.
The problem here is that the remote attribute buffers cannot have a
valid LSN placed into them, because the transaction that contains
the attribute tree pointer changes and the block allocation that the
attribute data is being written to hasn't yet been committed. Hence
the LSN field in the attribute block is completely unwritten,
thereby leaving the underlying contents of the block in the LSN
field. It could have any value, and hence a future overwrite of the
block by log recovery may or may not work correctly.
Fix this by always writing an invalid LSN to the remote attribute
block, as any buffer in log recovery that needs to write over the
remote attribute should occur. We are protected from having old data
written over the attribute by the fact that freeing the block before
the remote attribute is written will result in the buffer being
marked stale in the log and so all changes prior to the buffer stale
transaction will be cancelled by log recovery.
Hence it is safe to ignore the LSN in the case or synchronously
written, unlogged metadata such as remote attribute blocks, and to
ensure we do that correctly, we need to write an invalid LSN to all
remote attribute blocks to trigger immediate recovery of metadata
that is written over the top.
As a further protection for filesystems that may already have remote
attribute blocks with bad LSNs on disk, change the log recovery code
to always trigger immediate recovery of metadata over remote
attribute blocks.
cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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When modifying the patch series to handle the XFS MMAP_LOCK nesting
of page faults, I botched the conversion of the read page fault
path, and so it is only every calling through the page cache. Re-add
the necessary __dax_fault() call for such files.
Because the get_blocks callback on read faults may not set up the
mapping buffer correctly to allow unwritten extent completion to be
run, we need to allow callers of __dax_fault() to pass a null
complete_unwritten() callback. The DAX code always zeros the
unwritten page when it is read faulted so there are no stale data
exposure issues with not doing the conversion. The only downside
will be the potential for increased CPU overhead on repeated read
faults of the same page. If this proves to be a problem, then the
filesystem needs to fix it's get_block callback and provide a
convert_unwritten() callback to the read fault path.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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This reverts commit dec4f799d0a4c9edae20512fa60b0a36f3299ca2.
Jörg Otte reports a NULL pointder dereference due to this commit, as
'crtc_state' very much can be NULL:
crtc_state = state->base.state ?
intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL;
So the change to test 'crtc_state->base.active' cannot possibly be
correct as-is.
There may be some other minimal fix (like just checking crtc_state for
NULL), but I'm just reverting it now for the rc2 release, and people
like Daniel Vetter who actually know this code will figure out what the
right solution is in the longer term.
Reported-and-bisected-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS fixes from Al Viro:
"Fixes for this cycle regression in overlayfs and a couple of
long-standing (== all the way back to 2.6.12, at least) bugs"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
freeing unlinked file indefinitely delayed
fix a braino in ovl_d_select_inode()
9p: don't leave a half-initialized inode sitting around
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Pull MIPS fixes from Ralf Baechle:
"A fair number of 4.2 fixes also because Markos opened the flood gates.
- Patch up the math used calculate the location for the page bitmap.
- The FDC (Not what you think, FDC stands for Fast Debug Channel) IRQ
around was causing issues on non-Malta platforms, so move the code
to a Malta specific location.
- A spelling fix replicated through several files.
- Fix to the emulation of an R2 instruction for R6 cores.
- Fix the JR emulation for R6.
- Further patching of mindless 64 bit issues.
- Ensure the kernel won't crash on CPUs with L2 caches with >= 8
ways.
- Use compat_sys_getsockopt for O32 ABI on 64 bit kernels.
- Fix cache flushing for multithreaded cores.
- A build fix"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: O32: Use compat_sys_getsockopt.
MIPS: c-r4k: Extend way_string array
MIPS: Pistachio: Support CDMM & Fast Debug Channel
MIPS: Malta: Make GIC FDC IRQ workaround Malta specific
MIPS: c-r4k: Fix cache flushing for MT cores
Revert "MIPS: Kconfig: Disable SMP/CPS for 64-bit"
MIPS: cps-vec: Use macros for various arithmetics and memory operations
MIPS: kernel: cps-vec: Replace KSEG0 with CKSEG0
MIPS: kernel: cps-vec: Use ta0-ta3 pseudo-registers for 64-bit
MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2
MIPS: kernel: cps-vec: Replace 'la' macro with PTR_LA
MIPS: kernel: smp-cps: Fix 64-bit compatibility errors due to pointer casting
MIPS: Fix erroneous JR emulation for MIPS R6
MIPS: Fix branch emulation for BLTC and BGEC instructions
MIPS: kernel: traps: Fix broken indentation
MIPS: bootmem: Don't use memory holes for page bitmap
MIPS: O32: Do not handle require 32 bytes from the stack to be readable.
MIPS, CPUFREQ: Fix spelling of Institute.
MIPS: Lemote 2F: Fix build caused by recent mass rename.
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
- the high latency PIT detection fix, which slipped through the cracks
for rc1
- a regression fix for the early printk mechanism
- the x86 part to plug irq/vector related hotplug races
- move the allocation of the espfix pages on cpu hotplug to non atomic
context. The current code triggers a might_sleep() warning.
- a series of KASAN fixes addressing boot crashes and usability
- a trivial typo fix for Kconfig help text
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kconfig: Fix typo in the CONFIG_CMDLINE_BOOL help text
x86/irq: Retrieve irq data after locking irq_desc
x86/irq: Use proper locking in check_irq_vectors_for_cpu_disable()
x86/irq: Plug irq vector hotplug race
x86/earlyprintk: Allow early_printk() to use console style parameters like '115200n8'
x86/espfix: Init espfix on the boot CPU side
x86/espfix: Add 'cpu' parameter to init_espfix_ap()
x86/kasan: Move KASAN_SHADOW_OFFSET to the arch Kconfig
x86/kasan: Add message about KASAN being initialized
x86/kasan: Fix boot crash on AMD processors
x86/kasan: Flush TLBs after switching CR3
x86/kasan: Fix KASAN shadow region page tables
x86/init: Clear 'init_level4_pgt' earlier
x86/tsc: Let high latency PIT fail fast in quick_pit_calibrate()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"This update from the timer departement contains:
- A series of patches which address a shortcoming in the tick
broadcast code.
If the broadcast device is not available or an hrtimer emulated
broadcast device, some of the original assumptions lead to boot
failures. I rather plugged all of the corner cases instead of only
addressing the issue reported, so the change got a little larger.
Has been extensivly tested on x86 and arm.
- Get rid of the last holdouts using do_posix_clock_monotonic_gettime()
- A regression fix for the imx clocksource driver
- An update to the new state callbacks mechanism for clockevents.
This is required to simplify the conversion, which will take place
in 4.3"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/broadcast: Prevent NULL pointer dereference
time: Get rid of do_posix_clock_monotonic_gettime
cris: Replace do_posix_clock_monotonic_gettime()
tick/broadcast: Unbreak CONFIG_GENERIC_CLOCKEVENTS=n build
tick/broadcast: Handle spurious interrupts gracefully
tick/broadcast: Check for hrtimer broadcast active early
tick/broadcast: Return busy when IPI is pending
tick/broadcast: Return busy if periodic mode and hrtimer broadcast
tick/broadcast: Move the check for periodic mode inside state handling
tick/broadcast: Prevent deep idle if no broadcast device available
tick/broadcast: Make idle check independent from mode and config
tick/broadcast: Sanity check the shutdown of the local clock_event
tick/broadcast: Prevent hrtimer recursion
clockevents: Allow set-state callbacks to be optional
clocksource/imx: Define clocksource for mx27
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
"A single fix for a cpu hotplug race vs. interrupt descriptors:
Prevent irq setup/teardown across the cpu starting/dying parts of cpu
hotplug so that the starting/dying cpu has a stable view of the
descriptor space. This has been an issue for all architectures in the
cpu dying phase, where interrupts are migrated away from the dying
cpu. In the starting phase its mostly a x86 issue vs the vector space
update"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hotplug: Prevent alloc/free of irq descriptors during cpu up/down
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Normally opening a file, unlinking it and then closing will have
the inode freed upon close() (provided that it's not otherwise busy and
has no remaining links, of course). However, there's one case where that
does *not* happen. Namely, if you open it by fhandle with cold dcache,
then unlink() and close().
In normal case you get d_delete() in unlink(2) notice that dentry
is busy and unhash it; on the final dput() it will be forcibly evicted from
dcache, triggering iput() and inode removal. In this case, though, we end
up with *two* dentries - disconnected (created by open-by-fhandle) and
regular one (used by unlink()). The latter will have its reference to inode
dropped just fine, but the former will not - it's considered hashed (it
is on the ->s_anon list), so it will stay around until the memory pressure
will finally do it in. As the result, we have the final iput() delayed
indefinitely. It's trivial to reproduce -
void flush_dcache(void)
{
system("mount -o remount,rw /");
}
static char buf[20 * 1024 * 1024];
main()
{
int fd;
union {
struct file_handle f;
char buf[MAX_HANDLE_SZ];
} x;
int m;
x.f.handle_bytes = sizeof(x);
chdir("/root");
mkdir("foo", 0700);
fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
close(fd);
name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
flush_dcache();
fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
unlink("foo/bar");
write(fd, buf, sizeof(buf));
system("df ."); /* 20Mb eaten */
close(fd);
system("df ."); /* should've freed those 20Mb */
flush_dcache();
system("df ."); /* should be the same as #2 */
}
will spit out something like
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 303843 1131 100% /
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 303843 1131 100% /
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 283282 21692 93% /
- inode gets freed only when dentry is finally evicted (here we trigger
than by remount; normally it would've happened in response to memory
pressure hell knows when).
Cc: stable@vger.kernel.org # v2.6.38+; earlier ones need s/kill_it/unhash_it/
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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when opening a directory we want the overlayfs inode, not one from
the topmost layer.
Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Cc: stable@vger.kernel.org # all branches
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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