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Recently I've been seeing xfs/051 fail on 1k block size filesystems.
Trying to trace the events during the test lead to the problem going
away, indicating that it was a race condition that lead to this
ASSERT failure:
XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 156
.....
[<ffffffff814e1257>] xfs_free_perag+0x87/0xb0
[<ffffffff814e21b9>] xfs_mountfs+0x4d9/0x900
[<ffffffff814e5dff>] xfs_fs_fill_super+0x3bf/0x4d0
[<ffffffff811d8800>] mount_bdev+0x180/0x1b0
[<ffffffff814e3ff5>] xfs_fs_mount+0x15/0x20
[<ffffffff811d90a8>] mount_fs+0x38/0x170
[<ffffffff811f4347>] vfs_kern_mount+0x67/0x120
[<ffffffff811f7018>] do_mount+0x218/0xd60
[<ffffffff811f7e5b>] SyS_mount+0x8b/0xd0
When I finally caught it with tracing enabled, I saw that AG 2 had
an elevated reference count and a buffer was responsible for it. I
tracked down the specific buffer, and found that it was missing the
final reference count release that would put it back on the LRU and
hence be found by xfs_wait_buftarg() calls in the log mount failure
handling.
The last four traces for the buffer before the assert were (trimmed
for relevance)
kworker/0:1-5259 xfs_buf_iodone: hold 2 lock 0 flags ASYNC
kworker/0:1-5259 xfs_buf_ioerror: hold 2 lock 0 error -5
mount-7163 xfs_buf_lock_done: hold 2 lock 0 flags ASYNC
mount-7163 xfs_buf_unlock: hold 2 lock 1 flags ASYNC
This is an async write that is completing, so there's nobody waiting
for it directly. Hence we call xfs_buf_relse() once all the
processing is complete. That does:
static inline void xfs_buf_relse(xfs_buf_t *bp)
{
xfs_buf_unlock(bp);
xfs_buf_rele(bp);
}
Now, it's clear that mount is waiting on the buffer lock, and that
it has been released by xfs_buf_relse() and gained by mount. This is
expected, because at this point the mount process is in
xfs_buf_delwri_submit() waiting for all the IO it submitted to
complete.
The mount process, however, is waiting on the lock for the buffer
because it is in xfs_buf_delwri_submit(). This waits for IO
completion, but it doesn't wait for the buffer reference owned by
the IO to go away. The mount process collects all the completions,
fails the log recovery, and the higher level code then calls
xfs_wait_buftarg() to free all the remaining buffers in the
filesystem.
The issue is that on unlocking the buffer, the scheduler has decided
that the mount process has higher priority than the the kworker
thread that is running the IO completion, and so immediately
switched contexts to the mount process from the semaphore unlock
code, hence preventing the kworker thread from finishing the IO
completion and releasing the IO reference to the buffer.
Hence by the time that xfs_wait_buftarg() is run, the buffer still
has an active reference and so isn't on the LRU list that the
function walks to free the remaining buffers. Hence we miss that
buffer and continue onwards to tear down the mount structures,
at which time we get find a stray reference count on the perag
structure. On a non-debug kernel, this will be ignored and the
structure torn down and freed. Hence when the kworker thread is then
rescheduled and the buffer released and freed, it will access a
freed perag structure.
The problem here is that when the log mount fails, we still need to
quiesce the log to ensure that the IO workqueues have returned to
idle before we run xfs_wait_buftarg(). By synchronising the
workqueues, we ensure that all IO completions are fully processed,
not just to the point where buffers have been unlocked. This ensures
we don't end up in the situation above.
cc: <stable@vger.kernel.org> # 3.18
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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This reverts commit 24ba16bb3d499c49974669cd8429c3e4138ab102 as it
prevents machines from suspending. This regression occurs when the
xfsaild is idle on entry to suspend, and so there s no activity to
wake it from it's idle sleep and hence see that it is supposed to
freeze. Hence the freezer times out waiting for it and suspend is
cancelled.
There is no obvious fix for this short of freezing the filesystem
properly, so revert this change for now.
cc: <stable@vger.kernel.org> # 4.4
Signed-off-by: Dave Chinner <david@fromorbit.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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When we do dquot readahead in log recovery, we do not use a verifier
as the underlying buffer may not have dquots in it. e.g. the
allocation operation hasn't yet been replayed. Hence we do not want
to fail recovery because we detect an operation to be replayed has
not been run yet. This problem was addressed for inodes in commit
d891400 ("xfs: inode buffers may not be valid during recovery
readahead") but the problem was not recognised to exist for dquots
and their buffers as the dquot readahead did not have a verifier.
The result of not using a verifier is that when the buffer is then
next read to replay a dquot modification, the dquot buffer verifier
will only be attached to the buffer if *readahead is not complete*.
Hence we can read the buffer, replay the dquot changes and then add
it to the delwri submission list without it having a verifier
attached to it. This then generates warnings in xfs_buf_ioapply(),
which catches and warns about this case.
Fix this and make it handle the same readahead verifier error cases
as for inode buffers by adding a new readahead verifier that has a
write operation as well as a read operation that marks the buffer as
not done if any corruption is detected. Also make sure we don't run
readahead if the dquot buffer has been marked as cancelled by
recovery.
This will result in readahead either succeeding and the buffer
having a valid write verifier, or readahead failing and the buffer
state requiring the subsequent read to resubmit the IO with the new
verifier. In either case, this will result in the buffer always
ending up with a valid write verifier on it.
Note: we also need to fix the inode buffer readahead error handling
to mark the buffer with EIO. Brian noticed the code I copied from
there wrong during review, so fix it at the same time. Add comments
linking the two functions that handle readahead verifier errors
together so we don't forget this behavioural link in future.
cc: <stable@vger.kernel.org> # 3.12 - current
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 we do inode readahead in log recovery, we do can do the
readahead before we've replayed the icreate transaction that stamps
the buffer with inode cores. The inode readahead verifier catches
this and marks the buffer as !done to indicate that it doesn't yet
contain valid inodes.
In adding buffer error notification (i.e. setting b_error = -EIO at
the same time as as we clear the done flag) to such a readahead
verifier failure, we can then get subsequent inode recovery failing
with this error:
XFS (dm-0): metadata I/O error: block 0xa00060 ("xlog_recover_do..(read#2)") error 5 numblks 32
This occurs when readahead completion races with icreate item replay
such as:
inode readahead
find buffer
lock buffer
submit RA io
....
icreate recovery
xfs_trans_get_buffer
find buffer
lock buffer
<blocks on RA completion>
.....
<ra completion>
fails verifier
clear XBF_DONE
set bp->b_error = -EIO
release and unlock buffer
<icreate gains lock>
icreate initialises buffer
marks buffer as done
adds buffer to delayed write queue
releases buffer
At this point, we have an initialised inode buffer that is up to
date but has an -EIO state registered against it. When we finally
get to recovering an inode in that buffer:
inode item recovery
xfs_trans_read_buffer
find buffer
lock buffer
sees XBF_DONE is set, returns buffer
sees bp->b_error is set
fail log recovery!
Essentially, we need xfs_trans_get_buf_map() to clear the error status of
the buffer when doing a lookup. This function returns uninitialised
buffers, so the buffer returned can not be in an error state and
none of the code that uses this function expects b_error to be set
on return. Indeed, there is an ASSERT(!bp->b_error); in the
transaction case in xfs_trans_get_buf_map() that would have caught
this if log recovery used transactions....
This patch firstly changes the inode readahead failure to set -EIO
on the buffer, and secondly changes xfs_buf_get_map() to never
return a buffer with an error state set so this first change doesn't
cause unexpected log recovery failures.
cc: <stable@vger.kernel.org> # 3.12 - current
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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Calls to xfs_bmap_finish() and xfs_trans_ijoin(), and the
associated comments were replicated several times across
the attribute code, all dealing with what to do if the
transaction was or wasn't committed.
And in that replicated code, an ASSERT() test of an
uninitialized variable occurs in several locations:
error = xfs_attr_thing(&args);
if (!error) {
error = xfs_bmap_finish(&args.trans, args.flist,
&committed);
}
if (error) {
ASSERT(committed);
If the first xfs_attr_thing() failed, we'd skip the xfs_bmap_finish,
never set "committed", and then test it in the ASSERT.
Fix this up by moving the committed state internal to xfs_bmap_finish,
and add a new inode argument. If an inode is passed in, it is passed
through to __xfs_trans_roll() and joined to the transaction there if
the transaction was committed.
xfs_qm_dqalloc() was a little unique in that it called bjoin rather
than ijoin, but as Dave points out we can detect the committed state
but checking whether (*tpp != tp).
Addresses-Coverity-Id: 102360
Addresses-Coverity-Id: 102361
Addresses-Coverity-Id: 102363
Addresses-Coverity-Id: 102364
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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For large sparse or fragmented files, checking every single entry in
the bmapbt on every operation is prohibitively expensive. Especially
as such checks rarely discover problems during normal operations on
high extent coutn files. Our regression tests don't tend to exercise
files with hundreds of thousands to millions of extents, so mostly
this isn't noticed.
However, trying to run things like xfs_mdrestore of large filesystem
dumps on a debug kernel quickly becomes impossible as the CPU is
completely burnt up repeatedly walking the sparse file bmapbt that
is generated for every allocation that is made.
Hence, if the file has more than 10,000 extents, just don't bother
with walking the tree to check it exhaustively. The btree code has
checks that ensure that the newly inserted/removed/modified record
is correctly ordered, so the entrie tree walk in thses cases has
limited additional value.
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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This allows us to see page cache driven readahead in action as it
passes through XFS. This helps to understand buffered read
throughput problems such as readahead IO IO sizes being too small
for the underlying device to reach max throughput.
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 now uses CRC verification over a limited section of the log to
detect torn writes prior to a crash. This is difficult to test directly
due to the timing and hardware requirements to cause a short write.
Add a mechanism to inject CRC errors into log records to facilitate
testing torn write detection during log recovery. This mechanism is
dangerous and can result in filesystem corruption. Thus, it is only
available in DEBUG mode for testing/development purposes. Set a non-zero
value to the following sysfs entry to enable error injection:
/sys/fs/xfs/<dev>/log/log_badcrc_factor
Once enabled, XFS intentionally writes an invalid CRC to a log record at
some random point in the future based on the provided frequency. The
filesystem immediately shuts down once the record has been written to
the physical log to prevent metadata writeback (e.g., AIL insertion)
once the log write completes. This helps reasonably simulate a torn
write to the log as the affected record must be safe to discard. The
next mount after the intentional shutdown requires log recovery and
should detect and recover from the torn write.
Note again that this _will_ result in data loss or worse. For testing
and development purposes only!
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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Certain types of storage, such as persistent memory, do not provide
sector atomicity for writes. This means that if a crash occurs while XFS
is writing log records, only part of those records might make it to the
storage. This is problematic because log recovery uses the cycle value
packed at the top of each log block to locate the head/tail of the log.
This can lead to CRC verification failures during log recovery and an
unmountable fs for a filesystem that is otherwise consistent.
Update log recovery to incorporate log record CRC verification as part
of the head/tail discovery process. Once the head is located via the
traditional algorithm, run a CRC-only pass over the records up to the
head of the log. If CRC verification fails, assume that the records are
torn as a matter of policy and trim the head block back to the start of
the first bad record.
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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Rather than just being able to turn DAX on and off via a mount
option, some applications may only want to enable DAX for certain
performance critical files in a filesystem.
This patch introduces a new inode flag to enable DAX in the v3 inode
di_flags2 field. It adds support for setting and clearing flags in
the di_flags2 field via the XFS_IOC_FSSETXATTR ioctl, and sets the
S_DAX inode flag appropriately when it is seen.
When this flag is set on a directory, it acts as an "inherit flag".
That is, inodes created in the directory will automatically inherit
the on-disk inode DAX flag, enabling administrators to set up
directory heirarchies that automatically use DAX. Setting this flag
on an empty root directory will make the entire filesystem use DAX
by default.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Now that the ioctls have been hoisted up to the VFS level, use
the VFs definitions directly and remove the XFS specific definitions
completely. Userspace is going to have to handle the change of this
interface separately, so removing the definitions from xfs_fs.h is
not an issue here at all.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Hoist the ioctl definitions for the XFS_IOC_FS[SG]SETXATTR API from
fs/xfs/libxfs/xfs_fs.h to include/uapi/linux/fs.h so that the ioctls
can be used by all filesystems, not just XFS. This enables
(initially) ext4 to use the ioctl to set project IDs on inodes.
Based-on-patch-from: Li Xi <lixi@ddn.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Doing a splice read (generic/249) generates a lockdep splat because
we recursively lock the inode iolock in this path:
SyS_sendfile64
do_sendfile
do_splice_direct
splice_direct_to_actor
do_splice_to
xfs_file_splice_read <<<<<< lock here
default_file_splice_read
vfs_readv
do_readv_writev
do_iter_readv_writev
xfs_file_read_iter <<<<<< then here
The issue here is that for DAX inodes we need to avoid the page
cache path and hence simply push it into the normal read path.
Unfortunately, we can't tell down at xfs_file_read_iter() whether we
are being called from the splice path and hence we cannot avoid the
locking at this layer. Hence we simply have to drop the inode
locking at the higher splice layer for DAX.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Commit 1ca1915 ("xfs: Don't use unwritten extents for DAX") enabled
the DAX allocation call to dip into the reserve pool in case it was
converting unwritten extents rather than allocating blocks. This was
a direct copy of the unwritten extent conversion code, but had an
unintended side effect of allowing normal data block allocation to
use the reserve pool. Hence normal block allocation could deplete
the reserve pool and prevent unwritten extent conversion at ENOSPC,
hence violating fallocate guarantees on preallocated space.
Fix it by checking whether the incoming map from __xfs_get_blocks()
spans an unwritten extent and only use the reserve pool if the
allocation covers an unwritten extent.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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The return type "unsigned long" was used by the suffix_kstrtoint()
function even though it will eventually return a negative error code.
Improve this implementation detail by using the type "int" instead.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Create xfs_btree_sblock_verify() to verify short-format btree blocks
(i.e. the per-AG btrees with 32-bit block pointers) instead of
open-coding them.
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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Because struct xfs_agfl is 36 bytes long and has a 64-bit integer
inside it, gcc will quietly round the structure size up to the nearest
64 bits -- in this case, 40 bytes. This results in the XFS_AGFL_SIZE
macro returning incorrect results for v5 filesystems on 64-bit
machines (118 items instead of 119). As a result, a 32-bit xfs_repair
will see garbage in AGFL item 119 and complain.
Therefore, tell gcc not to pad the structure so that the AGFL size
calculation is correct.
cc: <stable@vger.kernel.org> # 3.10 - 4.4
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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Use a convenience variable instead of open-coding the inode fork.
This isn't really needed for now, but will become important when we
add the copy-on-write fork later.
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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Update the log ticket reservation type printing code to reflect
all the types of log tickets, to avoid incorrect debug output and
avoid running off the end of the array.
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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Since xfs_repair wants to use xfs_alloc_fix_freelist, remove the
static designation. xfsprogs already has this; this simply brings
the kernel up to date.
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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There are no callers of the xfs_buf_ioend_async() function outside
of the fs/xfs/xfs_buf.c. So, let's make it static.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Linux's quota subsystem has an ability to handle project quota. This
commit just utilizes the ability from xfs side. dbus-monitor and
quota_nld shipped as part of quota-tools can be used for testing.
See the patch posting on the XFS list for details on testing.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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In my earlier commit
c29aad4 xfs: pass mp to XFS_WANT_CORRUPTED_GOTO
I added some local mp variables with code which indicates that
mp might be NULL. Coverity doesn't like this now, because the
updated per-fs XFS_STATS macros dereference mp.
I don't think this is actually a problem; from what I can tell,
we cannot get to these functions with a null bma->tp, so my NULL
check was probably pointless. Still, it's not super obvious.
So switch this code to get mp from the inode on the xfs_bmalloca
structure, with no conditional, because the functions are already
using bmap->ip directly.
Addresses-Coverity-Id: 1339552
Addresses-Coverity-Id: 1339553
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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This adds a name to each buf_ops structure, so that if
a verifier fails we can print the type of verifier that
failed it. Should be a slight debugging aid, I hope.
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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If there is any non zero bit in a long bitmap, it can jump out of the
loop and finish the function as soon as possible.
Signed-off-by: Jia He <hejianet@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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As part of the head/tail discovery process, log recovery locates the
head block and then reverse seeks to find the start of the last active
record in the log. This is non-trivial as the record itself could have
wrapped around the end of the physical log. Log recovery torn write
detection potentially needs to walk further behind the last record in
the log, as multiple log I/Os can be in-flight at one time during a
crash event.
Therefore, refactor the reverse log record header search mechanism into
a new helper that supports the ability to seek past an arbitrary number
of log records (or until the tail is hit). Update the head/tail search
mechanism to call the new helper, but otherwise there is no change in
log recovery behavior.
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 torn write detection uses CRC verification over a range of
the active log to identify torn writes. Since the generic log recovery
pass code implements a superset of the functionality required for CRC
verification, it can be easily modified to support a CRC verification
only pass.
Create a new CRC pass type and update the log record processing helper
to skip everything beyond CRC verification when in this mode. This pass
will be invoked in subsequent patches to implement torn write detection.
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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Each log recovery pass walks from the tail block to the head block and
processes records appropriately based on the associated log pass type.
There are various failure conditions that can occur through this
sequence, such as I/O errors, CRC errors, etc. Log torn write detection
will perform CRC verification near the head of the log to detect torn
writes and trim torn records from the log appropriately.
As it is, xlog_do_recovery_pass() only returns an error code in the
event of CRC failure, which isn't enough information to trim the head of
the log. Update xlog_do_recovery_pass() to optionally return the start
block of the associated record when an error occurs. This patch contains
no functional changes.
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 record CRC verification currently occurs during active log recovery,
immediately before a log record is unpacked. Therefore, the CRC
calculation code is buried within the data unpack function. CRC
verification pass support only needs to go so far as check the CRC, but
this is not easily allowed as the code is currently organized.
Since we now have a new log record processing helper, pull the record
CRC verification code out from the unpack helper and open-code it at the
top of the new process helper. This facilitates the ability to modify
how records are processed based on the type of the current pass. This
patch contains no functional changes.
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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xlog_do_recovery_pass() duplicates a couple function calls related to
processing log records because the function must handle wrapping around
the end of the log if the head is behind the tail. This is implemented
as separate loops. CRC verification pass support will modify how records
are processed in both of these loops.
Rather than continue to duplicate code, factor the calls that process a
log record into a new helper and call that helper from both loops. This
patch contains no functional changes.
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 log records have separate fields for the record size and the iclog
size used to write the record. mkfs.xfs zeroes the log and writes an
unmount record to generate a clean log for the subsequent mount. The
userspace record logging code has a bug where the iclog size (h_size)
field of the log record is hardcoded to 32k, even if a log stripe unit
is specified. The log record length is correctly extended to the stripe
unit. Since the kernel log recovery code uses the h_size field to
determine the log buffer size, this means that the kernel can attempt to
read/process records larger than the buffer size and overrun the buffer.
This has historically not been a problem because the kernel doesn't
actually run through log recovery in the clean unmount case. Instead,
the kernel detects that a single unmount record exists between the head
and tail and pushes the tail forward such that the log is viewed as
clean (head == tail). Once CRC verification is enabled, however, all
records at the head of the log are verified for CRC errors and thus we
are susceptible to overrun problems if the iclog field is not correct.
While the core problem must be fixed in userspace, this is historical
behavior that must be detected in the kernel to avoid severe side
effects such as memory corruption and crashes. Update the log buffer
size calculation code to detect this condition, warn the user and resize
the log buffer based on the log stripe unit. Return a corruption error
in cases where this does not look like a clean filesystem (i.e., the log
record header indicates more than one operation).
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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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs xattr cleanups from Al Viro.
* 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
f2fs: xattr simplifications
squashfs: xattr simplifications
9p: xattr simplifications
xattr handlers: Pass handler to operations instead of flags
jffs2: Add missing capability check for listing trusted xattrs
hfsplus: Remove unused xattr handler list operations
ubifs: Remove unused security xattr handler
vfs: Fix the posix_acl_xattr_list return value
vfs: Check attribute names in posix acl xattr handers
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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>
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git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pull xfs updates from Dave Chinner:
"There is nothing really major here - the only significant addition is
the per-mount operation statistics infrastructure. Otherwises there's
various ACL, xattr, DAX, AIO and logging fixes, and a smattering of
small cleanups and fixes elsewhere.
Summary:
- per-mount operational statistics in sysfs
- fixes for concurrent aio append write submission
- various logging fixes
- detection of zeroed logs and invalid log sequence numbers on v5 filesystems
- memory allocation failure message improvements
- a bunch of xattr/ACL fixes
- fdatasync optimisation
- miscellaneous other fixes and cleanups"
* tag 'xfs-for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (39 commits)
xfs: give all workqueues rescuer threads
xfs: fix log recovery op header validation assert
xfs: Fix error path in xfs_get_acl
xfs: optimise away log forces on timestamp updates for fdatasync
xfs: don't leak uuid table on rmmod
xfs: invalidate cached acl if set via ioctl
xfs: Plug memory leak in xfs_attrmulti_attr_set
xfs: Validate the length of on-disk ACLs
xfs: invalidate cached acl if set directly via xattr
xfs: xfs_filemap_pmd_fault treats read faults as write faults
xfs: add ->pfn_mkwrite support for DAX
xfs: DAX does not use IO completion callbacks
xfs: Don't use unwritten extents for DAX
xfs: introduce BMAPI_ZERO for allocating zeroed extents
xfs: fix inode size update overflow in xfs_map_direct()
xfs: clear PF_NOFREEZE for xfsaild kthread
xfs: fix an error code in xfs_fs_fill_super()
xfs: stats are no longer dependent on CONFIG_PROC_FS
xfs: simplify /proc teardown & error handling
xfs: per-filesystem stats counter implementation
...
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The function currently called "__block_page_mkwrite()" used to be called
"block_page_mkwrite()" until a wrapper for this function was added by:
commit 24da4fab5a61 ("vfs: Create __block_page_mkwrite() helper passing
error values back")
This wrapper, the current "block_page_mkwrite()", is currently unused.
__block_page_mkwrite() is used directly by ext4, nilfs2 and xfs.
Remove the unused wrapper, rename __block_page_mkwrite() back to
block_page_mkwrite() and update the comment above block_page_mkwrite().
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Cc: Jan Kara <jack@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We're consistently hitting deadlocks here with XFS on recent kernels.
After some digging through the crash files, it looks like everyone in
the system is waiting for XFS to reclaim memory.
Something like this:
PID: 2733434 TASK: ffff8808cd242800 CPU: 19 COMMAND: "java"
#0 [ffff880019c53588] __schedule at ffffffff818c4df2
#1 [ffff880019c535d8] schedule at ffffffff818c5517
#2 [ffff880019c535f8] _xfs_log_force_lsn at ffffffff81316348
#3 [ffff880019c53688] xfs_log_force_lsn at ffffffff813164fb
#4 [ffff880019c536b8] xfs_iunpin_wait at ffffffff8130835e
#5 [ffff880019c53728] xfs_reclaim_inode at ffffffff812fd453
#6 [ffff880019c53778] xfs_reclaim_inodes_ag at ffffffff812fd8c7
#7 [ffff880019c53928] xfs_reclaim_inodes_nr at ffffffff812fe433
#8 [ffff880019c53958] xfs_fs_free_cached_objects at ffffffff8130d3b9
#9 [ffff880019c53968] super_cache_scan at ffffffff811a6f73
#10 [ffff880019c539c8] shrink_slab at ffffffff811460e6
#11 [ffff880019c53aa8] shrink_zone at ffffffff8114a53f
#12 [ffff880019c53b48] do_try_to_free_pages at ffffffff8114a8ba
#13 [ffff880019c53be8] try_to_free_pages at ffffffff8114ad5a
#14 [ffff880019c53c78] __alloc_pages_nodemask at ffffffff8113e1b8
#15 [ffff880019c53d88] alloc_kmem_pages_node at ffffffff8113e671
#16 [ffff880019c53dd8] copy_process at ffffffff8104f781
#17 [ffff880019c53ec8] do_fork at ffffffff8105129c
#18 [ffff880019c53f38] sys_clone at ffffffff810515b6
#19 [ffff880019c53f48] stub_clone at ffffffff818c8e4d
xfs_log_force_lsn is waiting for logs to get cleaned, which is waiting
for IO, which is waiting for workers to complete the IO which is waiting
for worker threads that don't exist yet:
PID: 2752451 TASK: ffff880bd6bdda00 CPU: 37 COMMAND: "kworker/37:1"
#0 [ffff8808d20abbb0] __schedule at ffffffff818c4df2
#1 [ffff8808d20abc00] schedule at ffffffff818c5517
#2 [ffff8808d20abc20] schedule_timeout at ffffffff818c7c6c
#3 [ffff8808d20abcc0] wait_for_completion_killable at ffffffff818c6495
#4 [ffff8808d20abd30] kthread_create_on_node at ffffffff8106ec82
#5 [ffff8808d20abdf0] create_worker at ffffffff8106752f
#6 [ffff8808d20abe40] worker_thread at ffffffff810699be
#7 [ffff8808d20abec0] kthread at ffffffff8106ef59
#8 [ffff8808d20abf50] ret_from_fork at ffffffff818c8ac8
I think we should be using WQ_MEM_RECLAIM to make sure this thread
pool makes progress when we're not able to allocate new workers.
[dchinner: make all workqueues WQ_MEM_RECLAIM]
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Commit 89cebc84 ("xfs: validate transaction header length on log
recovery") added additional validation of the on-disk op header length
to protect from buffer overflow during log recovery. It accounts for the
fact that the transaction header can be split across multiple op
headers. It added an assert for when this occurs that verifies the
length of the second part of a split transaction header is less than a
full transaction header. In other words, it expects that the first op
header of a split transaction header includes at least some portion of
the transaction header.
This expectation is not always valid as a zero-length op header can
exist for the first op header of a split transaction header (see
xlog_recover_add_to_trans() for details). This means that the second op
header can have a valid, full length transaction header and thus the
full header is copied in xlog_recover_add_to_cont_trans(). Fix the
assert in xlog_recover_add_to_cont_trans() to handle this case correctly
and require that the op header length is less than or equal to a full
transaction header.
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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Error codes from xfs_attr_get other than -ENOATTR were not properly
reported. Fix that.
In addition, the declaration of struct xfs_inode in xfs_acl.h isn't needed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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xfs: timestamp updates cause excessive fdatasync log traffic
Sage Weil reported that a ceph test workload was writing to the
log on every fdatasync during an overwrite workload. Event tracing
showed that the only metadata modification being made was the
timestamp updates during the write(2) syscall, but fdatasync(2)
is supposed to ignore them. The key observation was that the
transactions in the log all looked like this:
INODE: #regs: 4 ino: 0x8b flags: 0x45 dsize: 32
And contained a flags field of 0x45 or 0x85, and had data and
attribute forks following the inode core. This means that the
timestamp updates were triggering dirty relogging of previously
logged parts of the inode that hadn't yet been flushed back to
disk.
There are two parts to this problem. The first is that XFS relogs
dirty regions in subsequent transactions, so it carries around the
fields that have been dirtied since the last time the inode was
written back to disk, not since the last time the inode was forced
into the log.
The second part is that on v5 filesystems, the inode change count
update during inode dirtying also sets the XFS_ILOG_CORE flag, so
on v5 filesystems this makes a timestamp update dirty the entire
inode.
As a result when fdatasync is run, it looks at the dirty fields in
the inode, and sees more than just the timestamp flag, even though
the only metadata change since the last fdatasync was just the
timestamps. Hence we force the log on every subsequent fdatasync
even though it is not needed.
To fix this, add a new field to the inode log item that tracks
changes since the last time fsync/fdatasync forced the log to flush
the changes to the journal. This flag is updated when we dirty the
inode, but we do it before updating the change count so it does not
carry the "core dirty" flag from timestamp updates. The fields are
zeroed when the inode is marked clean (due to writeback/freeing) or
when an fsync/datasync forces the log. Hence if we only dirty the
timestamps on the inode between fsync/fdatasync calls, the fdatasync
will not trigger another log force.
Over 100 runs of the test program:
Ext4 baseline:
runtime: 1.63s +/- 0.24s
avg lat: 1.59ms +/- 0.24ms
iops: ~2000
XFS, vanilla kernel:
runtime: 2.45s +/- 0.18s
avg lat: 2.39ms +/- 0.18ms
log forces: ~400/s
iops: ~1000
XFS, patched kernel:
runtime: 1.49s +/- 0.26s
avg lat: 1.46ms +/- 0.25ms
log forces: ~30/s
iops: ~1500
Reported-by: Sage Weil <sage@redhat.com>
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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Don't leak the UUID table when the module is unloaded.
(Found with kmemleak.)
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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Setting or removing the "SGI_ACL_[FILE|DEFAULT]" attributes via the
XFS_IOC_ATTRMULTI_BY_HANDLE ioctl completely bypasses the POSIX ACL
infrastructure, like setting the "trusted.SGI_ACL_[FILE|DEFAULT]" xattrs
did until commit 6caa1056. Similar to that commit, invalidate cached
acls when setting/removing them via the ioctl as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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