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Given how XFS is all based around btrees it doesn't make much sense
to offer a totally generic state when we can just use the btree cursor.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
All defer op instance place their own extension of the log item into
the dfp_done field. Replace that with a xfs_log_item to improve type
safety and make the code easier to follow.
Also use the opportunity to improve the ->finish_item calling conventions
to place the done log item as the higher level structure before the
list_entry used for the individual items.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Split out a helper that operates on a single xfs_defer_pending structure
to untangle the code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
All defer op instance place their own extension of the log item into
the dfp_intent field. Replace that with a xfs_log_item to improve type
safety and make the code easier to follow.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This avoids a per-item indirect call, and also simplifies the interface
a bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
These are aways called together, and my merging them we reduce the amount
of indirect calls, improve type safety and in general clean up the code
a bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Create a helper that encapsulates the whole logic to create a defer
intent. This reorders some of the work that was done, but none of
that has an affect on the operation as only fields that don't directly
interact are affected.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Split out a xlog_add_buffer_cancelled helper which does the low-level
manipulation of the buffer cancelation table, and in that helper call
xlog_find_buffer_cancelled instead of open coding it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Don't bother to allocate memory and convert the log item when we
only need the block number and the length. Just extract them directly
and call xlog_buf_readahead separately in each branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Add a little helper to readahead a buffer if it hasn't been cancelled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This list contains pretty much everything that is not a buffer. The
comment calls it item_list, which is a much better name than inode
list, so switch the actual variable name to that as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Replace the somewhat convoluted use of xlog_peek_buffer_cancelled and
xlog_check_buffer_cancelled with two obvious helpers:
xlog_is_buffer_cancelled, which returns true if there is a buffer in
the cancellation table, and
xlog_put_buffer_cancelled, which also decrements the reference count
of the buffer cancellation table.
Both share a little helper to look up the entry.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
There are a couple places where we directly call printk_once() and one
of them doesn't follow the standard xfs subsystem printk format as a
result.
#define printk_once variants to go with our existing printk_ratelimited
#defines so we can do one-shot printks in a consistent manner.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
I ran into a linker warning in XFS that originates from a mismatch
between libelf, binutils and objtool when certain files in the kernel
are built with "gcc -g":
x86_64-linux-ld: fs/xfs/xfs_trace.o: unable to initialize decompress status for section .debug_info
After some discussion, nobody could identify why xfs sets this flag
here. CONFIG_XFS_DEBUG used to enable lots of unrelated settings, but
now its main purpose is to enable extra consistency checks and assertions
that are unrelated to the debug info.
Remove the Makefile logic to set the flag here. If anyone relies
on the debug info, this can simply be enabled again with the global
CONFIG_DEBUG_INFO option.
Dave Chinner writes:
I'm pretty sure it was needed for the original kgdb integration back
in the early 2000s. That was when SGI used to patch their XFS dev
tree with kgdb and debug symbols were needed by the custom kgdb
modules that were ported across from the Irix kernel debugger.
ISTR that the early kcrash kernel dump analysis tools (again,
originated from the Irix "icrash" kernel dump tools) had custom XFS
debug scripts that needed also the debug info to work correctly...
Which is a long way of saying "we don't need it anymore" instead of
"nobody knows why it was set"... :)
Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/20200409074130.GD21033@infradead.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Since the "no-allocation" reservations has been removed, the resblks
value should be larger than zero, so remove the unnecessary check.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Simplify the setting of the flags value, and only consider
quota enforcement stuff here.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The check XFS_IS_QUOTA_RUNNING() has been done when enter the
xfs_qm_vop_create_dqattach() function, it will return directly
if the result is false, so the followed XFS_IS_QUOTA_RUNNING()
assertion is unnecessary. If we truly care about this, the check
also can be added to the condition of next if statements.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The initial value of variable udqp is NULL, and we only set the
flag XFS_QMOPT_PQUOTA in xfs_qm_vop_dqalloc() function, so only
the pdqp value is initialized and the udqp value is still NULL.
Since the udqp value is NULL in the rest part of xfs_ioctl_setattr()
function, it is meaningless and do nothing. So remove it from
xfs_ioctl_setattr().
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
We share an inode between gquota and pquota with the older
superblock that doesn't have separate pquotino, and for the
need_alloc == false case we don't need to call xfs_dir_ialloc()
function, so add the check if reserved free disk blocks is
needed.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The two if statements have same condition, and the mask value
does not change in xfs_setattr_nonsize(), so combine them.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The trace event xfs_dquot_dqalloc does not depend on the
value uq, so remove the condition, and trace quota allocations
for all quota types.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
When we're sorting recovered log items ahead of recovering them and
encounter a log item of unknown type, actually print the type code when
we're rejecting the whole transaction to aid in debugging.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the inode dirty data flushing to a workqueue so that multiple
threads can take advantage of a single thread's flushing work. The
ratelimiting technique used in bdd4ee4 was not successful, because
threads that skipped the inode flush scan due to ratelimiting would
ENOSPC early, which caused occasional (but noticeable) changes in
behavior and sporadic fstest regressions.
Therefore, make all the writer threads wait on a single inode flush,
which eliminates both the stampeding hordes of flushers and the small
window in which a write could fail with ENOSPC because it lost the
ratelimit race after even another thread freed space.
Fixes: c6425702f21e ("xfs: ratelimit inode flush on buffered write ENOSPC")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized. Specifically, br_state was not
being copied from the passed-in struct to the uirec. This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The filesystem freeze sequence in XFS waits on any background
eofblocks or cowblocks scans to complete before the filesystem is
quiesced. At this point, the freezer has already stopped the
transaction subsystem, however, which means a truncate or cowblock
cancellation in progress is likely blocked in transaction
allocation. This results in a deadlock between freeze and the
associated scanner.
Fix this problem by holding superblock write protection across calls
into the block reapers. Since protection for background scans is
acquired from the workqueue task context, trylock to avoid a similar
deadlock between freeze and blocking on the write lock.
Fixes: d6b636ebb1c9f ("xfs: halt auto-reclamation activities while rebuilding rmap")
Reported-by: Paul Furtado <paulfurtado91@gmail.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reflink should force the log out to disk if the filesystem was mounted
with wsync, the same as most other operations in xfs.
[Note: XFS_MOUNT_WSYNC is set when the admin mounts the filesystem
with either the 'wsync' or 'sync' mount options, which effectively means
that we're classifying reflink/dedupe as IO operations and making them
synchronous when required.]
Fixes: 3fc9f5e409319 ("xfs: remove xfs_reflink_remap_range")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
[darrick: add more to the changelog]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Create a new helper to force the log up to the last LSN touching an
inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Qian Cai reports seemingly random buffer read verifier errors during
filesystem writeback. This was isolated to a recent patch that
factored out some inode cluster freeing code and happened to cast an
unsigned inode number type to a signed value. If the inode number
value overflows, we can skip marking in-core inodes associated with
the underlying buffer stale at the time the physical inodes are
freed. If such an inode happens to be dirty, xfsaild will eventually
attempt to write it back over non-inode blocks. The invalidation of
the underlying inode buffer causes writeback to read the buffer from
disk. This fails the read verifier (preventing eventual corruption)
if the buffer no longer looks like an inode cluster. Analysis by
Dave Chinner.
Fix up the helper to use the proper type for inode number values.
Fixes: 5806165a6663 ("xfs: factor inode lookup from xfs_ifree_cluster")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The variables 'udqp' and 'gdqp' have been initialized, so remove
redundant variable assignment in xfs_symlink().
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
A customer reported rcu stalls and softlockup warnings on a computer
with many CPU cores and many many more IO threads trying to write to a
filesystem that is totally out of space. Subsequent analysis pointed to
the many many IO threads calling xfs_flush_inodes -> sync_inodes_sb,
which causes a lot of wb_writeback_work to be queued. The writeback
worker spends so much time trying to wake the many many threads waiting
for writeback completion that it trips the softlockup detector, and (in
this case) the system automatically reboots.
In addition, they complain that the lengthy xfs_flush_inodes scan traps
all of those threads in uninterruptible sleep, which hampers their
ability to kill the program or do anything else to escape the situation.
If there's thousands of threads trying to write to files on a full
filesystem, each of those threads will start separate copies of the
inode flush scan. This is kind of pointless since we only need one
scan, so rate limit the inode flush.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If the inode buffer backing a particular inode is locked,
xfs_iflush() returns -EAGAIN and xfs_inode_item_push() skips the
inode. It still returns success to xfsaild, however, which bypasses
the xfsaild backoff heuristic. Update xfs_inode_item_push() to
return locked status if the inode buffer couldn't be locked.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
A dquot flush currently blocks on the buffer lock for the underlying
dquot buffer. In turn, this causes xfsaild to block rather than
continue processing other items in the meantime. Update
xfs_qm_dqflush() to trylock the buffer, similar to how inode buffers
are handled, and return -EAGAIN if the lock fails. Fix up any
callers that don't currently handle the error properly.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Since the "no-allocation" reservations for file creations has
been removed, the resblks value should be larger than zero, so
remove unnecessary ternary conditional.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: s/judgment/ternary/]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
In commit f467cad95f5e3, I added the ability to force a recalculation of
the filesystem summary counters if they seemed incorrect. This was done
(not entirely correctly) by tweaking the log code to write an unmount
record without the UMOUNT_TRANS flag set. At next mount, the log
recovery code will fail to find the unmount record and go into recovery,
which triggers the recalculation.
What actually gets written to the log is what ought to be an unmount
record, but without any flags set to indicate what kind of record it
actually is. This worked to trigger the recalculation, but we shouldn't
write bogus log records when we could simply write nothing.
Fixes: f467cad95f5e3 ("xfs: force summary counter recalc at next mount")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
There's lots of indent in this code which makes it a bit hard to
follow. We are also going to completely rework the inode lookup code
as part of the inode reclaim rework, so factor out the inode lookup
code from the inode cluster freeing code.
Based on prototype code from Christoph Hellwig.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
We currently wake anything waiting on the log tail to move whenever
the log item at the tail of the log is removed. Historically this
was fine behaviour because there were very few items at any given
LSN. But with delayed logging, there may be thousands of items at
any given LSN, and we can't move the tail until they are all gone.
Hence if we are removing them in near tail-first order, we might be
waking up processes waiting on the tail LSN to change (e.g. log
space waiters) repeatedly without them being able to make progress.
This also occurs with the new sync push waiters, and can result in
thousands of spurious wakeups every second when under heavy direct
reclaim pressure.
To fix this, check that the tail LSN has actually changed on the
AIL before triggering wakeups. This will reduce the number of
spurious wakeups when doing bulk AIL removal and make this code much
more efficient.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Factor the common AIL deletion code that does all the wakeups into a
helper so we only have one copy of this somewhat tricky code to
interface with all the wakeups necessary when the LSN of the log
tail changes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The XFS inode item slab actually reclaimed by inode shrinker
callbacks from the memory reclaim subsystem. These should be marked
as reclaimable so the mm subsystem has the full picture of how much
memory it can actually reclaim from the XFS slab caches.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The buffer cache shrinker frees more than just the xfs_buf slab
objects - it also frees the pages attached to the buffers. Make sure
the memory reclaim code accounts for this memory being freed
correctly, similar to how the inode shrinker accounts for pages
freed from the page cache due to mapping invalidation.
We also need to make sure that the mm subsystem knows these are
reclaimable objects. We provide the memory reclaim subsystem with a
a shrinker to reclaim xfs_bufs, so we should really mark the slab
that way.
We also have a lot of xfs_bufs in a busy system, spread them around
like we do inodes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Running metadata intensive workloads, I've been seeing the AIL
pushing getting stuck on pinned buffers and triggering log forces.
The log force is taking a long time to run because the log IO is
getting throttled by wbt_wait() - the block layer writeback
throttle. It's being throttled because there is a huge amount of
metadata writeback going on which is filling the request queue.
IOWs, we have a priority inversion problem here.
Mark the log IO bios with REQ_IDLE so they don't get throttled
by the block layer writeback throttle. When we are forcing the CIL,
we are likely to need to to tens of log IOs, and they are issued as
fast as they can be build and IO completed. Hence REQ_IDLE is
appropriate - it's an indication that more IO will follow shortly.
And because we also set REQ_SYNC, the writeback throttle will now
treat log IO the same way it treats direct IO writes - it will not
throttle them at all. Hence we solve the priority inversion problem
caused by the writeback throttle being unable to distinguish between
high priority log IO and background metadata writeback.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
In certain situations the background CIL push can be indefinitely
delayed. While we have workarounds from the obvious cases now, it
doesn't solve the underlying issue. This issue is that there is no
upper limit on the CIL where we will either force or wait for
a background push to start, hence allowing the CIL to grow without
bound until it consumes all log space.
To fix this, add a new wait queue to the CIL which allows background
pushes to wait for the CIL context to be switched out. This happens
when the push starts, so it will allow us to block incoming
transaction commit completion until the push has started. This will
only affect processes that are running modifications, and only when
the CIL threshold has been significantly overrun.
This has no apparent impact on performance, and doesn't even trigger
until over 45 million inodes had been created in a 16-way fsmark
test on a 2GB log. That was limiting at 64MB of log space used, so
the active CIL size is only about 3% of the total log in that case.
The concurrent removal of those files did not trigger the background
sleep at all.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The current CIL size aggregation limit is 1/8th the log size. This
means for large logs we might be aggregating at least 250MB of dirty objects
in memory before the CIL is flushed to the journal. With CIL shadow
buffers sitting around, this means the CIL is often consuming >500MB
of temporary memory that is all allocated under GFP_NOFS conditions.
Flushing the CIL can take some time to do if there is other IO
ongoing, and can introduce substantial log force latency by itself.
It also pins the memory until the objects are in the AIL and can be
written back and reclaimed by shrinkers. Hence this threshold also
tends to determine the minimum amount of memory XFS can operate in
under heavy modification without triggering the OOM killer.
Modify the CIL space limit to prevent such huge amounts of pinned
metadata from aggregating. We can have 2MB of log IO in flight at
once, so limit aggregation to 16x this size. This threshold was
chosen as it little impact on performance (on 16-way fsmark) or log
traffic but pins a lot less memory on large logs especially under
heavy memory pressure. An aggregation limit of 8x had 5-10%
performance degradation and a 50% increase in log throughput for
the same workload, so clearly that was too small for highly
concurrent workloads on large logs.
This was found via trace analysis of AIL behaviour. e.g. insertion
from a single CIL flush:
xfs_ail_insert: old lsn 0/0 new lsn 1/3033090 type XFS_LI_INODE flags IN_AIL
$ grep xfs_ail_insert /mnt/scratch/s.t |grep "new lsn 1/3033090" |wc -l
1721823
$
So there were 1.7 million objects inserted into the AIL from this
CIL checkpoint, the first at 2323.392108, the last at 2325.667566 which
was the end of the trace (i.e. it hadn't finished). Clearly a major
problem.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Separate out the unmount record writing from the rest of the
ticket and log state futzing necessary to make it work. This is
a no-op, just makes the code cleaner and places the unmount record
formatting and writing alongside the commit record formatting and
writing code.
We can also get rid of the ticket flag clearing before the
xlog_write() call because it no longer cares about the state of
XLOG_TIC_INITED.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
xlog_write_done() is just a thin wrapper around xlog_commit_record(), so
they can be merged together easily.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Remove xlog_ticket_done and just call the renamed low-level helpers for
ungranting or regranting log space directly. To make that a little
the reference put on the ticket and all tracing is moved into the actual
helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
It is not longer used or checked by anything, so remove the last
traces from the log ticket code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
