Ever since 6.12-rc1, I've observed a pile of warnings from the kernel
when running fstests with quotas enabled:
WARNING: CPU: 1 PID: 458580 at mm/page_alloc.c:4221 __alloc_pages_noprof+0xc9c/0xf18
CPU: 1 UID: 0 PID: 458580 Comm: xfsaild/sda3 Tainted: G W 6.12.0-rc6-djwa #rc6 6ee3e0e531f6457e2d26aa008a3b65ff184b377c
<snip>
Call trace:
__alloc_pages_noprof+0xc9c/0xf18
alloc_pages_mpol_noprof+0x94/0x240
alloc_pages_noprof+0x68/0xf8
new_slab+0x3e0/0x568
___slab_alloc+0x5a0/0xb88
__slab_alloc.constprop.0+0x7c/0xf8
__kmalloc_noprof+0x404/0x4d0
xfs_buf_get_map+0x594/0xde0 [xfs 384cb02810558b4c490343c164e9407332118f88]
xfs_buf_read_map+0x64/0x2e0 [xfs 384cb02810558b4c490343c164e9407332118f88]
xfs_trans_read_buf_map+0x1dc/0x518 [xfs 384cb02810558b4c490343c164e9407332118f88]
xfs_qm_dqflush+0xac/0x468 [xfs 384cb02810558b4c490343c164e9407332118f88]
xfs_qm_dquot_logitem_push+0xe4/0x148 [xfs 384cb02810558b4c490343c164e9407332118f88]
xfsaild+0x3f4/0xde8 [xfs 384cb02810558b4c490343c164e9407332118f88]
kthread+0x110/0x128
ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
This corresponds to the line:
WARN_ON_ONCE(current->flags & PF_MEMALLOC);
within the NOFAIL checks. What's happening here is that the XFS AIL is
trying to write a disk quota update back into the filesystem, but for
that it needs to read the ondisk buffer for the dquot. The buffer is
not in memory anymore, probably because it was evicted. Regardless, the
buffer cache tries to allocate a new buffer, but those allocations are
NOFAIL. The AIL thread has marked itself PF_MEMALLOC (aka noreclaim)
since commit 43ff2122e6 ("xfs: on-stack delayed write buffer lists")
presumably because reclaim can push on XFS to push on the AIL.
An easy way to fix this probably would have been to drop the NOFAIL flag
from the xfs_buf allocation and open code a retry loop, but then there's
still the problem that for bs>ps filesystems, the buffer itself could
require up to 64k worth of pages.
Inode items had similar behavior (multi-page cluster buffers that we
don't want to allocate in the AIL) which we solved by making transaction
precommit attach the inode cluster buffers to the dirty log item. Let's
solve the dquot problem in the same way.
So: Make a real precommit handler to read the dquot buffer and attach it
to the log item; pass it to dqflush in the push method; and have the
iodone function detach the buffer once we've flushed everything. Add a
state flag to the log item to track when a thread has entered the
precommit -> push mechanism to skip the detaching if it turns out that
the dquot is very busy, as we don't hold the dquot lock between log item
commit and AIL push).
Reading and attaching the dquot buffer in the precommit hook is inspired
by the work done for inode cluster buffers some time ago.
Cc: <stable@vger.kernel.org> # v6.12
Fixes: 903edea6c5 ("mm: warn about illegal __GFP_NOFAIL usage in a more appropriate location and manner")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Disabling quota accounting is hairy, racy code with all kinds of pitfalls.
And it has a very strange mind set, as quota accounting (unlike
enforcement) really is a propery of the on-disk format. There is no good
use case for supporting this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
AIL removal of the quotaoff start intent and free of both intents is
hardcoded to the ->iop_committed() handler of the end intent. Factor
out the start intent handling code so it can be used in a future
patch to properly handle quotaoff errors. Use xfs_trans_ail_remove()
instead of the _delete() variant to acquire the AIL lock and also
handle cases where an intent might not reside in the AIL at the
time of a failure.
Signed-off-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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Reichl <preichl@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix a comment]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Pavel Reichl <preichl@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>
Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/
This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:
for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done
And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:
$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}
/^ \* This program is free software/ {
hdr = 2.0;
next
}
/any later version./ {
tag = "GPL-2.0+"
next
}
/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}
/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}
/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}
// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}
END { }
$
Signed-off-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>
This one doesn't save a whole lot of memory, but still makes the
code simpler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
No need to keep the dquot log format around all the time, we can
easily generate it at iop_format time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the
annoying subdirectories in the XFS source code. Besides the large
amount of file rename the only changes are to the Makefile, a few
files including headers with the subdirectory prefix, and the binary
sysctl compat code that includes a header under fs/xfs/ from
kernel/.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
