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git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fs hole punching vs cache filling race fixes from Jan Kara:
"Fix races leading to possible data corruption or stale data exposure
in multiple filesystems when hole punching races with operations such
as readahead.
This is the series I was sending for the last merge window but with
your objection fixed - now filemap_fault() has been modified to take
invalidate_lock only when we need to create new page in the page cache
and / or bring it uptodate"
* tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
filesystems/locking: fix Malformed table warning
cifs: Fix race between hole punch and page fault
ceph: Fix race between hole punch and page fault
fuse: Convert to using invalidate_lock
f2fs: Convert to using invalidate_lock
zonefs: Convert to using invalidate_lock
xfs: Convert double locking of MMAPLOCK to use VFS helpers
xfs: Convert to use invalidate_lock
xfs: Refactor xfs_isilocked()
ext2: Convert to using invalidate_lock
ext4: Convert to use mapping->invalidate_lock
mm: Add functions to lock invalidate_lock for two mappings
mm: Protect operations adding pages to page cache with invalidate_lock
documentation: Sync file_operations members with reality
mm: Fix comments mentioning i_mutex
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Pull xfs fixes from Darrick Wong:
"This contains a bunch of bug fixes in XFS.
Dave and I have been busy the last couple of weeks to find and fix as
many log recovery bugs as we can find; here are the results so far. Go
fstests -g recoveryloop! ;)
- Fix a number of coordination bugs relating to cache flushes for
metadata writeback, cache flushes for multi-buffer log writes, and
FUA writes for single-buffer log writes
- Fix a bug with incorrect replay of attr3 blocks
- Fix unnecessary stalls when flushing logs to disk
- Fix spoofing problems when recovering realtime bitmap blocks"
* tag 'xfs-5.14-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: prevent spoofing of rtbitmap blocks when recovering buffers
xfs: limit iclog tail updates
xfs: need to see iclog flags in tracing
xfs: Enforce attr3 buffer recovery order
xfs: logging the on disk inode LSN can make it go backwards
xfs: avoid unnecessary waits in xfs_log_force_lsn()
xfs: log forces imply data device cache flushes
xfs: factor out forced iclog flushes
xfs: fix ordering violation between cache flushes and tail updates
xfs: fold __xlog_state_release_iclog into xlog_state_release_iclog
xfs: external logs need to flush data device
xfs: flush data dev on external log write
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While reviewing the buffer item recovery code, the thought occurred to
me: in V5 filesystems we use log sequence number (LSN) tracking to avoid
replaying older metadata updates against newer log items. However, we
use the magic number of the ondisk buffer to find the LSN of the ondisk
metadata, which means that if an attacker can control the layout of the
realtime device precisely enough that the start of an rt bitmap block
matches the magic and UUID of some other kind of block, they can control
the purported LSN of that spoofed block and thereby break log replay.
Since realtime bitmap and summary blocks don't have headers at all, we
have no way to tell if a block really should be replayed. The best we
can do is replay unconditionally and hope for the best.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
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From the department of "generic/482 keeps on giving", we bring you
another tail update race condition:
iclog:
S1 C1
+-----------------------+-----------------------+
S2 EOIC
Two checkpoints in a single iclog. One is complete, the other just
contains the start record and overruns into a new iclog.
Timeline:
Before S1: Cache flush, log tail = X
At S1: Metadata stable, write start record and checkpoint
At C1: Write commit record, set NEED_FUA
Single iclog checkpoint, so no need for NEED_FLUSH
Log tail still = X, so no need for NEED_FLUSH
After C1,
Before S2: Cache flush, log tail = X
At S2: Metadata stable, write start record and checkpoint
After S2: Log tail moves to X+1
At EOIC: End of iclog, more journal data to write
Releases iclog
Not a commit iclog, so no need for NEED_FLUSH
Writes log tail X+1 into iclog.
At this point, the iclog has tail X+1 and NEED_FUA set. There has
been no cache flush for the metadata between X and X+1, and the
iclog writes the new tail permanently to the log. THis is sufficient
to violate on disk metadata/journal ordering.
We have two options here. The first is to detect this case in some
manner and ensure that the partial checkpoint write sets NEED_FLUSH
when the iclog is already marked NEED_FUA and the log tail changes.
This seems somewhat fragile and quite complex to get right, and it
doesn't actually make it obvious what underlying problem it is
actually addressing from reading the code.
The second option seems much cleaner to me, because it is derived
directly from the requirements of the C1 commit record in the iclog.
That is, when we write this commit record to the iclog, we've
guaranteed that the metadata/data ordering is correct for tail
update purposes. Hence if we only write the log tail into the iclog
for the *first* commit record rather than the log tail at the last
release, we guarantee that the log tail does not move past where the
the first commit record in the log expects it to be.
IOWs, taking the first option means that replay of C1 becomes
dependent on future operations doing the right thing, not just the
C1 checkpoint itself doing the right thing. This makes log recovery
almost impossible to reason about because now we have to take into
account what might or might not have happened in the future when
looking at checkpoints in the log rather than just having to
reconstruct the past...
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Because I cannot tell if the NEED_FLUSH flag is being set correctly
by the log force and CIL push machinery without it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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From the department of "WTAF? How did we miss that!?"...
When we are recovering a buffer, the first thing we do is check the
buffer magic number and extract the LSN from the buffer. If the LSN
is older than the current LSN, we replay the modification to it. If
the metadata on disk is newer than the transaction in the log, we
skip it. This is a fundamental v5 filesystem metadata recovery
behaviour.
generic/482 failed with an attribute writeback failure during log
recovery. The write verifier caught the corruption before it got
written to disk, and the attr buffer dump looked like:
XFS (dm-3): Metadata corruption detected at xfs_attr3_leaf_verify+0x275/0x2e0, xfs_attr3_leaf block 0x19be8
XFS (dm-3): Unmount and run xfs_repair
XFS (dm-3): First 128 bytes of corrupted metadata buffer:
00000000: 00 00 00 00 00 00 00 00 3b ee 00 00 4d 2a 01 e1 ........;...M*..
00000010: 00 00 00 00 00 01 9b e8 00 00 00 01 00 00 05 38 ...............8
^^^^^^^^^^^^^^^^^^^^^^^
00000020: df 39 5e 51 58 ac 44 b6 8d c5 e7 10 44 09 bc 17 .9^QX.D.....D...
00000030: 00 00 00 00 00 02 00 83 00 03 00 cc 0f 24 01 00 .............$..
00000040: 00 68 0e bc 0f c8 00 10 00 00 00 00 00 00 00 00 .h..............
00000050: 00 00 3c 31 0f 24 01 00 00 00 3c 32 0f 88 01 00 ..<1.$....<2....
00000060: 00 00 3c 33 0f d8 01 00 00 00 00 00 00 00 00 00 ..<3............
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
.....
The highlighted bytes are the LSN that was replayed into the
buffer: 0x100000538. This is cycle 1, block 0x538. Prior to replay,
that block on disk looks like this:
$ sudo xfs_db -c "fsb 0x417d" -c "type attr3" -c p /dev/mapper/thin-vol
hdr.info.hdr.forw = 0
hdr.info.hdr.back = 0
hdr.info.hdr.magic = 0x3bee
hdr.info.crc = 0xb5af0bc6 (correct)
hdr.info.bno = 105448
hdr.info.lsn = 0x100000900
^^^^^^^^^^^
hdr.info.uuid = df395e51-58ac-44b6-8dc5-e7104409bc17
hdr.info.owner = 131203
hdr.count = 2
hdr.usedbytes = 120
hdr.firstused = 3796
hdr.holes = 1
hdr.freemap[0-2] = [base,size]
Note the LSN stamped into the buffer on disk: 1/0x900. The version
on disk is much newer than the log transaction that was being
replayed. That's a bug, and should -never- happen.
So I immediately went to look at xlog_recover_get_buf_lsn() to check
that we handled the LSN correctly. I was wondering if there was a
similar "two commits with the same start LSN skips the second
replay" problem with buffers. I didn't get that far, because I found
a much more basic, rudimentary bug: xlog_recover_get_buf_lsn()
doesn't recognise buffers with XFS_ATTR3_LEAF_MAGIC set in them!!!
IOWs, attr3 leaf buffers fall through the magic number checks
unrecognised, so trigger the "recover immediately" behaviour instead
of undergoing an LSN check. IOWs, we incorrectly replay ATTR3 leaf
buffers and that causes silent on disk corruption of inode attribute
forks and potentially other things....
Git history shows this is *another* zero day bug, this time
introduced in commit 50d5c8d8e938 ("xfs: check LSN ordering for v5
superblocks during recovery") which failed to handle the attr3 leaf
buffers in recovery. And we've failed to handle them ever since...
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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When we log an inode, we format the "log inode" core and set an LSN
in that inode core. We do that via xfs_inode_item_format_core(),
which calls:
xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn);
to format the log inode. It writes the LSN from the inode item into
the log inode, and if recovery decides the inode item needs to be
replayed, it recovers the log inode LSN field and writes it into the
on disk inode LSN field.
Now this might seem like a reasonable thing to do, but it is wrong
on multiple levels. Firstly, if the item is not yet in the AIL,
item->li_lsn is zero. i.e. the first time the inode it is logged and
formatted, the LSN we write into the log inode will be zero. If we
only log it once, recovery will run and can write this zero LSN into
the inode.
This means that the next time the inode is logged and log recovery
runs, it will *always* replay changes to the inode regardless of
whether the inode is newer on disk than the version in the log and
that violates the entire purpose of recording the LSN in the inode
at writeback time (i.e. to stop it going backwards in time on disk
during recovery).
Secondly, if we commit the CIL to the journal so the inode item
moves to the AIL, and then relog the inode, the LSN that gets
stamped into the log inode will be the LSN of the inode's current
location in the AIL, not it's age on disk. And it's not the LSN that
will be associated with the current change. That means when log
recovery replays this inode item, the LSN that ends up on disk is
the LSN for the previous changes in the log, not the current
changes being replayed. IOWs, after recovery the LSN on disk is not
in sync with the LSN of the modifications that were replayed into
the inode. This, again, violates the recovery ordering semantics
that on-disk writeback LSNs provide.
Hence the inode LSN in the log dinode is -always- invalid.
Thirdly, recovery actually has the LSN of the log transaction it is
replaying right at hand - it uses it to determine if it should
replay the inode by comparing it to the on-disk inode's LSN. But it
doesn't use that LSN to stamp the LSN into the inode which will be
written back when the transaction is fully replayed. It uses the one
in the log dinode, which we know is always going to be incorrect.
Looking back at the change history, the inode logging was broken by
commit 93f958f9c41f ("xfs: cull unnecessary icdinode fields") way
back in 2016 by a stupid idiot who thought he knew how this code
worked. i.e. me. That commit replaced an in memory di_lsn field that
was updated only at inode writeback time from the inode item.li_lsn
value - and hence always contained the same LSN that appeared in the
on-disk inode - with a read of the inode item LSN at inode format
time. CLearly these are not the same thing.
Before 93f958f9c41f, the log recovery behaviour was irrelevant,
because the LSN in the log inode always matched the on-disk LSN at
the time the inode was logged, hence recovery of the transaction
would never make the on-disk LSN in the inode go backwards or get
out of sync.
A symptom of the problem is this, caught from a failure of
generic/482. Before log recovery, the inode has been allocated but
never used:
xfs_db> inode 393388
xfs_db> p
core.magic = 0x494e
core.mode = 0
....
v3.crc = 0x99126961 (correct)
v3.change_count = 0
v3.lsn = 0
v3.flags2 = 0
v3.cowextsize = 0
v3.crtime.sec = Thu Jan 1 10:00:00 1970
v3.crtime.nsec = 0
After log recovery:
xfs_db> p
core.magic = 0x494e
core.mode = 020444
....
v3.crc = 0x23e68f23 (correct)
v3.change_count = 2
v3.lsn = 0
v3.flags2 = 0
v3.cowextsize = 0
v3.crtime.sec = Thu Jul 22 17:03:03 2021
v3.crtime.nsec = 751000000
...
You can see that the LSN of the on-disk inode is 0, even though it
clearly has been written to disk. I point out this inode, because
the generic/482 failure occurred because several adjacent inodes in
this specific inode cluster were not replayed correctly and still
appeared to be zero on disk when all the other metadata (inobt,
finobt, directories, etc) indicated they should be allocated and
written back.
The fix for this is two-fold. The first is that we need to either
revert the LSN changes in 93f958f9c41f or stop logging the inode LSN
altogether. If we do the former, log recovery does not need to
change but we add 8 bytes of memory per inode to store what is
largely a write-only inode field. If we do the latter, log recovery
needs to stamp the on-disk inode in the same manner that inode
writeback does.
I prefer the latter, because we shouldn't really be trying to log
and replay changes to the on disk LSN as the on-disk value is the
canonical source of the on-disk version of the inode. It also
matches the way we recover buffer items - we create a buf_log_item
that carries the current recovery transaction LSN that gets stamped
into the buffer by the write verifier when it gets written back
when the transaction is fully recovered.
However, this might break log recovery on older kernels even more,
so I'm going to simply ignore the logged value in recovery and stamp
the on-disk inode with the LSN of the transaction being recovered
that will trigger writeback on transaction recovery completion. This
will ensure that the on-disk inode LSN always reflects the LSN of
the last change that was written to disk, regardless of whether it
comes from log recovery or runtime writeback.
Fixes: 93f958f9c41f ("xfs: cull unnecessary icdinode fields")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Before waiting on a iclog in xfs_log_force_lsn(), we don't check to
see if the iclog has already been completed and the contents on
stable storage. We check for completed iclogs in xfs_log_force(), so
we should do the same thing for xfs_log_force_lsn().
This fixed some random up-to-30s pauses seen in unmounting
filesystems in some tests. A log force ends up waiting on completed
iclog, and that doesn't then get flushed (and hence the log force
get completed) until the background log worker issues a log force
that flushes the iclog in question. Then the unmount unblocks and
continues.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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After fixing the tail_lsn vs cache flush race, generic/482 continued
to fail in a similar way where cache flushes were missing before
iclog FUA writes. Tracing of iclog state changes during the fsstress
workload portion of the test (via xlog_iclog* events) indicated that
iclog writes were coming from two sources - CIL pushes and log
forces (due to fsync/O_SYNC operations). All of the cases where a
recovery problem was triggered indicated that the log force was the
source of the iclog write that was not preceeded by a cache flush.
This was an oversight in the modifications made in commit
eef983ffeae7 ("xfs: journal IO cache flush reductions"). Log forces
for fsync imply a data device cache flush has been issued if an
iclog was flushed to disk and is indicated to the caller via the
log_flushed parameter so they can elide the device cache flush if
the journal issued one.
The change in eef983ffeae7 results in iclogs only issuing a cache
flush if XLOG_ICL_NEED_FLUSH is set on the iclog, but this was not
added to the iclogs that the log force code flushes to disk. Hence
log forces are no longer guaranteeing that a cache flush is issued,
hence opening up a potential on-disk ordering failure.
Log forces should also set XLOG_ICL_NEED_FUA as well to ensure that
the actual iclogs it forces to the journal are also on stable
storage before it returns to the caller.
This patch introduces the xlog_force_iclog() helper function to
encapsulate the process of taking a reference to an iclog, switching
its state if WANT_SYNC and flushing it to stable storage correctly.
Both xfs_log_force() and xfs_log_force_lsn() are converted to use
it, as is xlog_unmount_write() which has an elaborate method of
doing exactly the same "write this iclog to stable storage"
operation.
Further, if the log force code needs to wait on a iclog in the
WANT_SYNC state, it needs to ensure that iclog also results in a
cache flush being issued. This covers the case where the iclog
contains the commit record of the CIL flush that the log force
triggered, but it hasn't been written yet because there is still an
active reference to the iclog.
Note: this whole cache flush whack-a-mole patch is a result of log
forces still being iclog state centric rather than being CIL
sequence centric. Most of this nasty code will go away in future
when log forces are converted to wait on CIL sequence push
completion rather than iclog completion. With the CIL push algorithm
guaranteeing that the CIL checkpoint is fully on stable storage when
it completes, we no longer need to iterate iclogs and push them to
ensure a CIL sequence push has completed and so all this nasty iclog
iteration and flushing code will go away.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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We force iclogs in several places - we need them all to have the
same cache flush semantics, so start by factoring out the iclog
force into a common helper.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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There is a race between the new CIL async data device metadata IO
completion cache flush and the log tail in the iclog the flush
covers being updated. This can be seen by repeating generic/482 in a
loop and eventually log recovery fails with a failures such as this:
XFS (dm-3): Starting recovery (logdev: internal)
XFS (dm-3): bad inode magic/vsn daddr 228352 #0 (magic=0)
XFS (dm-3): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x37c00 xfs_inode_buf_verify
XFS (dm-3): Unmount and run xfs_repair
XFS (dm-3): First 128 bytes of corrupted metadata buffer:
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
XFS (dm-3): metadata I/O error in "xlog_recover_items_pass2+0x55/0xc0" at daddr 0x37c00 len 32 error 117
Analysis of the logwrite replay shows that there were no writes to
the data device between the FUA @ write 124 and the FUA at write @
125, but log recovery @ 125 failed. The difference was the one log
write @ 125 moved the tail of the log forwards from (1,8) to (1,32)
and so the inode create intent in (1,8) was not replayed and so the
inode cluster was zero on disk when replay of the first inode item
in (1,32) was attempted.
What this meant was that the journal write that occurred at @ 125
did not ensure that metadata completed before the iclog was written
was correctly on stable storage. The tail of the log moved forward,
so IO must have been completed between the two iclog writes. This
means that there is a race condition between the unconditional async
cache flush in the CIL push work and the tail LSN that is written to
the iclog. This happens like so:
CIL push work AIL push work
------------- -------------
Add to committing list
start async data dev cache flush
.....
<flush completes>
<all writes to old tail lsn are stable>
xlog_write
.... push inode create buffer
<start IO>
.....
xlog_write(commit record)
.... <IO completes>
log tail moves
xlog_assign_tail_lsn()
start_lsn == commit_lsn
<no iclog preflush!>
xlog_state_release_iclog
__xlog_state_release_iclog()
<writes *new* tail_lsn into iclog>
xlog_sync()
....
submit_bio()
<tail in log moves forward without flushing written metadata>
Essentially, this can only occur if the commit iclog is issued
without a cache flush. If the iclog bio is submitted with
REQ_PREFLUSH, then it will guarantee that all the completed IO is
one stable storage before the iclog bio with the new tail LSN in it
is written to the log.
IOWs, the tail lsn that is written to the iclog needs to be sampled
*before* we issue the cache flush that guarantees all IO up to that
LSN has been completed.
To fix this without giving up the performance advantage of the
flush/FUA optimisations (e.g. g/482 runtime halves with 5.14-rc1
compared to 5.13), we need to ensure that we always issue a cache
flush if the tail LSN changes between the initial async flush and
the commit record being written. THis requires sampling the tail_lsn
before we start the flush, and then passing the sampled tail LSN to
xlog_state_release_iclog() so it can determine if the the tail LSN
has changed while writing the checkpoint. If the tail LSN has
changed, then it needs to set the NEED_FLUSH flag on the iclog and
we'll issue another cache flush before writing the iclog.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Fold __xlog_state_release_iclog into its only caller to prepare
make an upcoming fix easier.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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The recent journal flush/FUA changes replaced the flushing of the
data device on every iclog write with an up-front async data device
cache flush. Unfortunately, the assumption of which this was based
on has been proven incorrect by the flush vs log tail update
ordering issue. As the fix for that issue uses the
XLOG_ICL_NEED_FLUSH flag to indicate that data device needs a cache
flush, we now need to (once again) ensure that an iclog write to
external logs that need a cache flush to be issued actually issue a
cache flush to the data device as well as the log device.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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We incorrectly flush the log device instead of the data device when
trying to ensure metadata is correctly on disk before writing the
unmount record.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Pull xfs fixes from Darrick Wong:
"A few fixes for issues in the new online shrink code, additional
corrections for my recent bug-hunt w.r.t. extent size hints on
realtime, and improved input checking of the GROWFSRT ioctl.
IOW, the usual 'I somehow got bored during the merge window and
resumed auditing the farther reaches of xfs':
- Fix shrink eligibility checking when sparse inode clusters enabled
- Reset '..' directory entries when unlinking directories to prevent
verifier errors if fs is shrinked later
- Don't report unusable extent size hints to FSGETXATTR
- Don't warn when extent size hints are unusable because the sysadmin
configured them that way
- Fix insufficient parameter validation in GROWFSRT ioctl
- Fix integer overflow when adding rt volumes to filesystem"
* tag 'xfs-5.14-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: detect misaligned rtinherit directory extent size hints
xfs: fix an integer overflow error in xfs_growfs_rt
xfs: improve FSGROWFSRT precondition checking
xfs: don't expose misaligned extszinherit hints to userspace
xfs: correct the narrative around misaligned rtinherit/extszinherit dirs
xfs: reset child dir '..' entry when unlinking child
xfs: check for sparse inode clusters that cross new EOAG when shrinking
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If we encounter a directory that has been configured to pass on an
extent size hint to a new realtime file and the hint isn't an integer
multiple of the rt extent size, we should flag the hint for
administrative review because that is a misconfiguration (that other
parts of the kernel will fix automatically).
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
During a realtime grow operation, we run a single transaction for each
rt bitmap block added to the filesystem. This means that each step has
to be careful to increase sb_rblocks appropriately.
Fix the integer overflow error in this calculation that can happen when
the extent size is very large. Found by running growfs to add a rt
volume to a filesystem formatted with a 1g rt extent size.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
Improve the checking at the start of a realtime grow operation so that
we avoid accidentally set a new extent size that is too large and avoid
adding an rt volume to a filesystem with rmap or reflink because we
don't support rt rmap or reflink yet.
While we're at it, separate the checks so that we're only testing one
aspect at a time.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
Commit 603f000b15f2 changed xfs_ioctl_setattr_check_extsize to reject an
attempt to set an EXTSZINHERIT extent size hint on a directory with
RTINHERIT set if the hint isn't a multiple of the realtime extent size.
However, I have recently discovered that it is possible to change the
realtime extent size when adding a rt device to a filesystem, which
means that the existence of directories with misaligned inherited hints
is not an accident.
As a result, it's possible that someone could have set a valid hint and
added an rt volume with a different rt extent size, which invalidates
the ondisk hints. After such a sequence, FSGETXATTR will report a
misaligned hint, which FSSETXATTR will trip over, causing confusion if
the user was doing the usual GET/SET sequence to change some other
attribute. Change xfs_fill_fsxattr to omit the hint if it isn't aligned
properly.
Fixes: 603f000b15f2 ("xfs: validate extsz hints against rt extent size when rtinherit is set")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
While auditing the realtime growfs code, I realized that the GROWFSRT
ioctl (and by extension xfs_growfs) has always allowed sysadmins to
change the realtime extent size when adding a realtime section to the
filesystem. Since we also have always allowed sysadmins to set
RTINHERIT and EXTSZINHERIT on directories even if there is no realtime
device, this invalidates the premise laid out in the comments added in
commit 603f000b15f2.
In other words, this is not a case of inadequate metadata validation.
This is a case of nearly forgotten (and apparently untested) but
supported functionality. Update the comments to reflect what we've
learned, and remove the log message about correcting the misalignment.
Fixes: 603f000b15f2 ("xfs: validate extsz hints against rt extent size when rtinherit is set")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
While running xfs/168, I noticed a second source of post-shrink
corruption errors causing shutdowns.
Let's say that directory B has a low inode number and is a child of
directory A, which has a high number. If B is empty but open, and
unlinked from A, B's dotdot link continues to point to A. If A is then
unlinked and the filesystem shrunk so that A is no longer a valid inode,
a subsequent AIL push of B will trip the inode verifiers because the
dotdot entry points outside of the filesystem.
To avoid this problem, reset B's dotdot entry to the root directory when
unlinking directories, since the root directory cannot be removed.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
|
|
While running xfs/168, I noticed occasional write verifier shutdowns
involving inodes at the very end of the filesystem. Existing inode
btree validation code checks that all inode clusters are fully contained
within the filesystem.
However, due to inadequate checking in the fs shrink code, it's possible
that there could be a sparse inode cluster at the end of the filesystem
where the upper inodes of the cluster are marked as holes and the
corresponding blocks are free. In this case, the last blocks in the AG
are listed in the bnobt. This enables the shrink to proceed but results
in a filesystem that trips the inode verifiers. Fix this by disallowing
the shrink.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
|
|
Convert places in XFS that take MMAPLOCK for two inodes to use helper
VFS provides for it (filemap_invalidate_down_write_two()). Note that
this changes lock ordering for MMAPLOCK from inode number based ordering
to pointer based ordering VFS generally uses.
CC: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
|
|
Use invalidate_lock instead of XFS internal i_mmap_lock. The intended
purpose of invalidate_lock is exactly the same. Note that the locking in
__xfs_filemap_fault() slightly changes as filemap_fault() already takes
invalidate_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
CC: <linux-xfs@vger.kernel.org>
CC: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
|
|
Introduce a new __xfs_rwsem_islocked predicate to encapsulate checking
the state of a rw_semaphore, then refactor xfs_isilocked to use it.
Signed-off-by: Pavel Reichl <preichl@redhat.com>
Suggested-by: Dave Chinner <dchinner@redhat.com>
Suggested-by: Eric Sandeen <sandeen@redhat.com>
Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
|
|
In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fallthrough */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:
fs/xfs/libxfs/xfs_attr.c:487:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:500:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:532:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:594:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:607:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1410:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1445:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_attr.c:1473:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
Notice that Clang doesn't recognize /* fallthrough */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.
Link: https://github.com/KSPP/linux/issues/115
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
|
|
Pull xfs updates from Darrick Wong:
"Most of the work this cycle has been on refactoring various parts of
the codebase. The biggest non-cleanup changes are (1) reducing the
number of cache flushes sent when writing the log; (2) a substantial
number of log recovery fixes; and (3) I started accepting pull
requests from contributors if the commits in their branches match
what's been sent to the list.
For a week or so I /had/ staged a major cleanup of the logging code
from Dave Chinner, but it exposed so many lurking bugs in other parts
of the logging and log recovery code that I decided to defer that
patchset until we can address those latent bugs.
Larger cleanups this time include walking the incore inode cache (me)
and rework of the extended attribute code (Allison) to prepare it for
adding logged xattr updates (and directory tree parent pointers) in
future releases.
Summary:
- Refactor the buffer cache to use bulk page allocation
- Convert agnumber-based AG iteration to walk per-AG structures
- Clean up some unit conversions and other code warts
- Reduce spinlock contention in the directio fastpath
- Collapse all the inode cache walks into a single function
- Remove indirect function calls from the inode cache walk code
- Dramatically reduce the number of cache flushes sent when writing
log buffers
- Preserve inode sickness reports for longer
- Rename xfs_eofblocks since it controls inode cache walks
- Refactor the extended attribute code to prepare it for the addition
of log intent items to make xattrs fully transactional
- A few fixes to earlier large patchsets
- Log recovery fixes so that we don't accidentally mark the log clean
when log intent recovery fails
- Fix some latent SOB errors
- Clean up shutdown messages that get logged to dmesg
- Fix a regression in the online shrink code
- Fix a UAF in the buffer logging code if the fs goes offline
- Fix uninitialized error variables
- Fix a UAF in the CIL when commited log item callbacks race with a
shutdown
- Fix a bug where the CIL could hang trying to push part of the log
ring buffer that hasn't been filled yet"
* tag 'xfs-5.14-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (102 commits)
xfs: don't wait on future iclogs when pushing the CIL
xfs: Fix a CIL UAF by getting get rid of the iclog callback lock
xfs: remove callback dequeue loop from xlog_state_do_iclog_callbacks
xfs: don't nest icloglock inside ic_callback_lock
xfs: Initialize error in xfs_attr_remove_iter
xfs: fix endianness issue in xfs_ag_shrink_space
xfs: remove dead stale buf unpin handling code
xfs: hold buffer across unpin and potential shutdown processing
xfs: force the log offline when log intent item recovery fails
xfs: fix log intent recovery ENOSPC shutdowns when inactivating inodes
xfs: shorten the shutdown messages to a single line
xfs: print name of function causing fs shutdown instead of hex pointer
xfs: fix type mismatches in the inode reclaim functions
xfs: separate primary inode selection criteria in xfs_iget_cache_hit
xfs: refactor the inode recycling code
xfs: add iclog state trace events
xfs: xfs_log_force_lsn isn't passed a LSN
xfs: Fix CIL throttle hang when CIL space used going backwards
xfs: journal IO cache flush reductions
xfs: remove need_start_rec parameter from xlog_write()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core:
- BPF:
- add syscall program type and libbpf support for generating
instructions and bindings for in-kernel BPF loaders (BPF loaders
for BPF), this is a stepping stone for signed BPF programs
- infrastructure to migrate TCP child sockets from one listener to
another in the same reuseport group/map to improve flexibility
of service hand-off/restart
- add broadcast support to XDP redirect
- allow bypass of the lockless qdisc to improving performance (for
pktgen: +23% with one thread, +44% with 2 threads)
- add a simpler version of "DO_ONCE()" which does not require jump
labels, intended for slow-path usage
- virtio/vsock: introduce SOCK_SEQPACKET support
- add getsocketopt to retrieve netns cookie
- ip: treat lowest address of a IPv4 subnet as ordinary unicast
address allowing reclaiming of precious IPv4 addresses
- ipv6: use prandom_u32() for ID generation
- ip: add support for more flexible field selection for hashing
across multi-path routes (w/ offload to mlxsw)
- icmp: add support for extended RFC 8335 PROBE (ping)
- seg6: add support for SRv6 End.DT46 behavior
- mptcp:
- DSS checksum support (RFC 8684) to detect middlebox meddling
- support Connection-time 'C' flag
- time stamping support
- sctp: packetization Layer Path MTU Discovery (RFC 8899)
- xfrm: speed up state addition with seq set
- WiFi:
- hidden AP discovery on 6 GHz and other HE 6 GHz improvements
- aggregation handling improvements for some drivers
- minstrel improvements for no-ack frames
- deferred rate control for TXQs to improve reaction times
- switch from round robin to virtual time-based airtime scheduler
- add trace points:
- tcp checksum errors
- openvswitch - action execution, upcalls
- socket errors via sk_error_report
Device APIs:
- devlink: add rate API for hierarchical control of max egress rate
of virtual devices (VFs, SFs etc.)
- don't require RCU read lock to be held around BPF hooks in NAPI
context
- page_pool: generic buffer recycling
New hardware/drivers:
- mobile:
- iosm: PCIe Driver for Intel M.2 Modem
- support for Qualcomm MSM8998 (ipa)
- WiFi: Qualcomm QCN9074 and WCN6855 PCI devices
- sparx5: Microchip SparX-5 family of Enterprise Ethernet switches
- Mellanox BlueField Gigabit Ethernet (control NIC of the DPU)
- NXP SJA1110 Automotive Ethernet 10-port switch
- Qualcomm QCA8327 switch support (qca8k)
- Mikrotik 10/25G NIC (atl1c)
Driver changes:
- ACPI support for some MDIO, MAC and PHY devices from Marvell and
NXP (our first foray into MAC/PHY description via ACPI)
- HW timestamping (PTP) support: bnxt_en, ice, sja1105, hns3, tja11xx
- Mellanox/Nvidia NIC (mlx5)
- NIC VF offload of L2 bridging
- support IRQ distribution to Sub-functions
- Marvell (prestera):
- add flower and match all
- devlink trap
- link aggregation
- Netronome (nfp): connection tracking offload
- Intel 1GE (igc): add AF_XDP support
- Marvell DPU (octeontx2): ingress ratelimit offload
- Google vNIC (gve): new ring/descriptor format support
- Qualcomm mobile (rmnet & ipa): inline checksum offload support
- MediaTek WiFi (mt76)
- mt7915 MSI support
- mt7915 Tx status reporting
- mt7915 thermal sensors support
- mt7921 decapsulation offload
- mt7921 enable runtime pm and deep sleep
- Realtek WiFi (rtw88)
- beacon filter support
- Tx antenna path diversity support
- firmware crash information via devcoredump
- Qualcomm WiFi (wcn36xx)
- Wake-on-WLAN support with magic packets and GTK rekeying
- Micrel PHY (ksz886x/ksz8081): add cable test support"
* tag 'net-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2168 commits)
tcp: change ICSK_CA_PRIV_SIZE definition
tcp_yeah: check struct yeah size at compile time
gve: DQO: Fix off by one in gve_rx_dqo()
stmmac: intel: set PCI_D3hot in suspend
stmmac: intel: Enable PHY WOL option in EHL
net: stmmac: option to enable PHY WOL with PMT enabled
net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del}
net: use netdev_info in ndo_dflt_fdb_{add,del}
ptp: Set lookup cookie when creating a PTP PPS source.
net: sock: add trace for socket errors
net: sock: introduce sk_error_report
net: dsa: replay the local bridge FDB entries pointing to the bridge dev too
net: dsa: ensure during dsa_fdb_offload_notify that dev_hold and dev_put are on the same dev
net: dsa: include fdb entries pointing to bridge in the host fdb list
net: dsa: include bridge addresses which are local in the host fdb list
net: dsa: sync static FDB entries on foreign interfaces to hardware
net: dsa: install the host MDB and FDB entries in the master's RX filter
net: dsa: reference count the FDB addresses at the cross-chip notifier level
net: dsa: introduce a separate cross-chip notifier type for host FDBs
net: dsa: reference count the MDB entries at the cross-chip notifier level
...
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Merge misc updates from Andrew Morton:
"191 patches.
Subsystems affected by this patch series: kthread, ia64, scripts,
ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
pagealloc, and memory-failure)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
mm,hwpoison: make get_hwpoison_page() call get_any_page()
mm,hwpoison: send SIGBUS with error virutal address
mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
docs: remove description of DISCONTIGMEM
arch, mm: remove stale mentions of DISCONIGMEM
mm: remove CONFIG_DISCONTIGMEM
m68k: remove support for DISCONTIGMEM
arc: remove support for DISCONTIGMEM
arc: update comment about HIGHMEM implementation
alpha: remove DISCONTIGMEM and NUMA
mm/page_alloc: move free_the_page
mm/page_alloc: fix counting of managed_pages
mm/page_alloc: improve memmap_pages dbg msg
mm: drop SECTION_SHIFT in code comments
mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
mm/page_alloc: scale the number of pages that are batch freed
...
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Use __set_page_dirty_no_writeback() instead. This will set the dirty bit
on the page, which will be used to avoid calling set_page_dirty() in the
future. It will have no effect on actually writing the page back, as the
pages are not on any LRU lists.
[akpm@linux-foundation.org: export __set_page_dirty_no_writeback() to modules]
Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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The only difference between iomap_set_page_dirty() and
__set_page_dirty_nobuffers() is that the latter includes a debugging check
that a !Uptodate page has private data.
Link: https://lkml.kernel.org/r/20210615162342.1669332-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull fallthrough fixes from Gustavo Silva:
"Fix many fall-through warnings when building with Clang 12.0.0 and
'-Wimplicit-fallthrough' so that we at some point will be able to
enable that warning by default"
* tag 'fallthrough-fixes-clang-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (26 commits)
rxrpc: Fix fall-through warnings for Clang
drm/nouveau/clk: Fix fall-through warnings for Clang
drm/nouveau/therm: Fix fall-through warnings for Clang
drm/nouveau: Fix fall-through warnings for Clang
xfs: Fix fall-through warnings for Clang
xfrm: Fix fall-through warnings for Clang
tipc: Fix fall-through warnings for Clang
sctp: Fix fall-through warnings for Clang
rds: Fix fall-through warnings for Clang
net/packet: Fix fall-through warnings for Clang
net: netrom: Fix fall-through warnings for Clang
ide: Fix fall-through warnings for Clang
hwmon: (max6621) Fix fall-through warnings for Clang
hwmon: (corsair-cpro) Fix fall-through warnings for Clang
firewire: core: Fix fall-through warnings for Clang
braille_console: Fix fall-through warnings for Clang
ipv4: Fix fall-through warnings for Clang
qlcnic: Fix fall-through warnings for Clang
bnxt_en: Fix fall-through warnings for Clang
netxen_nic: Fix fall-through warnings for Clang
...
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Certain uses of "do once" functionality reside outside of fast path,
and so do not require jump label patching via static keys, making
existing DO_ONCE undesirable in such cases.
Replace uses of __section(".data.once") with DO_ONCE_LITE(_IF)?
This patch changes the return values of xfs_printk_once, printk_once,
and printk_deferred_once. Before, they returned whether the print was
performed, but now, they always return true. This is okay because the
return values of the following macros are entirely ignored throughout
the kernel:
- xfs_printk_once
- xfs_warn_once
- xfs_notice_once
- xfs_info_once
- printk_once
- pr_emerg_once
- pr_alert_once
- pr_crit_once
- pr_err_once
- pr_warn_once
- pr_notice_once
- pr_info_once
- pr_devel_once
- pr_debug_once
- printk_deferred_once
- orc_warn
Changes
v3:
- Expand commit message to explain why changing return values of
xfs_printk_once, printk_once, printk_deferred_once is benign
v2:
- Fix i386 build warnings
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The iclogbuf ring attached to the struct xlog is circular, hence the
first and last iclogs in the ring can only be determined by
comparing them against the log->l_iclog pointer.
In xfs_cil_push_work(), we want to wait on previous iclogs that were
issued so that we can flush them to stable storage with the commit
record write, and it simply waits on the previous iclog in the ring.
This, however, leads to CIL push hangs in generic/019 like so:
task:kworker/u33:0 state:D stack:12680 pid: 7 ppid: 2 flags:0x00004000
Workqueue: xfs-cil/pmem1 xlog_cil_push_work
Call Trace:
__schedule+0x30b/0x9f0
schedule+0x68/0xe0
xlog_wait_on_iclog+0x121/0x190
? wake_up_q+0xa0/0xa0
xlog_cil_push_work+0x994/0xa10
? _raw_spin_lock+0x15/0x20
? xfs_swap_extents+0x920/0x920
process_one_work+0x1ab/0x390
worker_thread+0x56/0x3d0
? rescuer_thread+0x3c0/0x3c0
kthread+0x14d/0x170
? __kthread_bind_mask+0x70/0x70
ret_from_fork+0x1f/0x30
With other threads blocking in either xlog_state_get_iclog_space()
waiting for iclog space or xlog_grant_head_wait() waiting for log
reservation space.
The problem here is that the previous iclog on the ring might
actually be a future iclog. That is, if log->l_iclog points at
commit_iclog, commit_iclog is the first (oldest) iclog in the ring
and there are no previous iclogs pending as they have all completed
their IO and been activated again. IOWs, commit_iclog->ic_prev
points to an iclog that will be written in the future, not one that
has been written in the past.
Hence, in this case, waiting on the ->ic_prev iclog is incorrect
behaviour, and depending on the state of the future iclog, we can
end up with a circular ABA wait cycle and we hang.
The fix is made more complex by the fact that many iclogs states
cannot be used to determine if the iclog is a past or future iclog.
Hence we have to determine past iclogs by checking the LSN of the
iclog rather than their state. A past ACTIVE iclog will have a LSN
of zero, while a future ACTIVE iclog will have a LSN greater than
the current iclog. We don't wait on either of these cases.
Similarly, a future iclog that hasn't completed IO will have an LSN
greater than the current iclog and so we don't wait on them. A past
iclog that is still undergoing IO completion will have a LSN less
than the current iclog and those are the only iclogs that we need to
wait on.
Hence we can use the iclog LSN to determine what iclogs we need to
wait on here.
Fixes: 5fd9256ce156 ("xfs: separate CIL commit record IO")
Reported-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
|
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The iclog callback chain has it's own lock. That was added way back
in 2008 by myself to alleviate severe lock contention on the
icloglock in commit 114d23aae512 ("[XFS] Per iclog callback chain
lock"). This was long before delayed logging took the icloglock out
of the hot transaction commit path and removed all contention on it.
Hence the separate ic_callback_lock doesn't serve any scalability
purpose anymore, and hasn't for close on a decade.
Further, we only attach callbacks to iclogs in one place where we
are already taking the icloglock soon after attaching the callbacks.
We also have to drop the icloglock to run callbacks and grab it
immediately afterwards again. So given that the icloglock is no
longer hot, making it cover callbacks again doesn't really change
the locking patterns very much at all.
We also need to extend the icloglock to cover callback addition to
fix a zero-day UAF in the CIL push code. This occurs when shutdown
races with xlog_cil_push_work() and the shutdown runs the callbacks
before the push releases the iclog. This results in the CIL context
structure attached to the iclog being freed by the callback before
the CIL push has finished referencing it, leading to UAF bugs.
Hence, to avoid this UAF, we need the callback attachment to be
atomic with post processing of the commit iclog and references to
the structures being attached to the iclog. This requires holding
the icloglock as that's the only way to serialise iclog state
against a shutdown in progress.
The result is we need to be using the icloglock to protect the
callback list addition and removal and serialise them with shutdown.
That makes the ic_callback_lock redundant and so it can be removed.
Fixes: 71e330b59390 ("xfs: Introduce delayed logging core code")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If we are processing callbacks on an iclog, nothing can be
concurrently adding callbacks to the loop. We only add callbacks to
the iclog when they are in ACTIVE or WANT_SYNC state, and we
explicitly do not add callbacks if the iclog is already in IOERROR
state.
The only way to have a dequeue racing with an enqueue is to be
processing a shutdown without a direct reference to an iclog in
ACTIVE or WANT_SYNC state. As the enqueue avoids this race
condition, we only ever need a single dequeue operation in
xlog_state_do_iclog_callbacks(). Hence we can remove the loop.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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It's completely unnecessary because callbacks are added to iclogs
without holding the icloglock, hence no amount of ordering between
the icloglock and ic_callback_lock will order the removal of
callbacks from the iclog.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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A recent bug report generated a warning that a code path in
xfs_attr_remove_iter could potentially return error uninitialized in the
case of XFS_DAS_RM_SHRINK state. Fix this by initializing error.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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The AGI buffer is in big-endian format, so we must convert the
endianness to CPU format to do any comparisons.
Fixes: 46141dc891f7 ("xfs: introduce xfs_ag_shrink_space()")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
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This code goes back to a time when transaction commits wrote
directly to iclogs. The associated log items were pinned, written to
the log, and then "uncommitted" if some part of the log write had
failed. This uncommit sequence called an ->iop_unpin_remove()
handler that was eventually folded into ->iop_unpin() via the remove
parameter. The log subsystem has since changed significantly in that
transactions commit to the CIL instead of direct to iclogs, though
log items must still be aborted in the event of an eventual log I/O
error. However, the context for a log item abort is now asynchronous
from transaction commit, which means the committing transaction has
been freed by this point in time and the transaction uncommit
sequence of events is no longer relevant.
Further, since stale buffers remain locked at transaction commit
through unpin, we can be certain that the buffer is not associated
with any transaction when the unpin callback executes. Remove this
unused hunk of code and replace it with an assertion that the buffer
is disassociated from transaction context.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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The special processing used to simulate a buffer I/O failure on fs
shutdown has a difficult to reproduce race that can result in a use
after free of the associated buffer. Consider a buffer that has been
committed to the on-disk log and thus is AIL resident. The buffer
lands on the writeback delwri queue, but is subsequently locked,
committed and pinned by another transaction before submitted for
I/O. At this point, the buffer is stuck on the delwri queue as it
cannot be submitted for I/O until it is unpinned. A log checkpoint
I/O failure occurs sometime later, which aborts the bli. The unpin
handler is called with the aborted log item, drops the bli reference
count, the pin count, and falls into the I/O failure simulation
path.
The potential problem here is that once the pin count falls to zero
in ->iop_unpin(), xfsaild is free to retry delwri submission of the
buffer at any time, before the unpin handler even completes. If
delwri queue submission wins the race to the buffer lock, it
observes the shutdown state and simulates the I/O failure itself.
This releases both the bli and delwri queue holds and frees the
buffer while xfs_buf_item_unpin() sits on xfs_buf_lock() waiting to
run through the same failure sequence. This problem is rare and
requires many iterations of fstest generic/019 (which simulates disk
I/O failures) to reproduce.
To avoid this problem, grab a hold on the buffer before the log item
is unpinned if the associated item has been aborted and will require
a simulated I/O failure. The hold is already required for the
simulated I/O failure, so the ordering simply guarantees the unpin
handler access to the buffer before it is unpinned and thus
processed by the AIL. This particular ordering is required so long
as the AIL does not acquire a reference on the bli, which is the
long term solution to this problem.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If any part of log intent item recovery fails, we should shut down the
log immediately to stop the log from writing a clean unmount record to
disk, because the metadata is not consistent. The inability to cancel a
dirty transaction catches most of these cases, but there are a few
things that have slipped through the cracks, such as ENOSPC from a
transaction allocation, or runtime errors that result in cancellation of
a non-dirty transaction.
This solves some weird behaviors reported by customers where a system
goes down, the first mount fails, the second succeeds, but then the fs
goes down later because of inconsistent metadata.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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During regular operation, the xfs_inactive operations create
transactions with zero block reservation because in general we're
freeing space, not asking for more. The per-AG space reservations
created at mount time enable us to handle expansions of the refcount
btree without needing to reserve blocks to the transaction.
Unfortunately, log recovery doesn't create the per-AG space reservations
when intent items are being recovered. This isn't an issue for intent
item recovery itself because they explicitly request blocks, but any
inode inactivation that can happen during log recovery uses the same
xfs_inactive paths as regular runtime. If a refcount btree expansion
happens, the transaction will fail due to blk_res_used > blk_res, and we
shut down the filesystem unnecessarily.
Fix this problem by making per-AG reservations temporarily so that we
can handle the inactivations, and releasing them at the end. This
brings the recovery environment closer to the runtime environment.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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Consolidate the shutdown messages to a single line containing the
reason, the passed-in flags, the source of the shutdown, and the end
result. This means we now only have one line to look for when
debugging, which is useful when the fs goes down while something else is
flooding dmesg.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
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In xfs_do_force_shutdown, print the symbolic name of the function that
called us to shut down the filesystem instead of a raw hex pointer.
This makes debugging a lot easier:
XFS (sda): xfs_do_force_shutdown(0x2) called from line 2440 of file
fs/xfs/xfs_log.c. Return address = ffffffffa038bc38
becomes:
XFS (sda): xfs_do_force_shutdown(0x2) called from line 2440 of file
fs/xfs/xfs_log.c. Return address = xfs_trans_mod_sb+0x25
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
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It's currently unlikely that we will ever end up with more than 4
billion inodes waiting for reclamation, but the fs object code uses long
int for object counts and we're certainly capable of generating that
many. Instead of truncating the internal counters, widen them and
report the object counts correctly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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During review of the v6 deferred inode inactivation patchset[1], Dave
commented that _cache_hit should have a clear separation between inode
selection criteria and actions performed on a selected inode. Move a
hunk to make this true, and compact the shrink cases in the function.
[1] https://lore.kernel.org/linux-xfs/162310469340.3465262.504398465311182657.stgit@locust/T/#mca6d958521cb88bbc1bfe1a30767203328d410b5
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
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Hoist the code in xfs_iget_cache_hit that restores the VFS inode state
to an xfs_inode that was previously vfs-destroyed. The next patch will
add a new set of state flags, so we need the helper to avoid
duplication.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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For the DEBUGS!
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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In doing an investigation into AIL push stalls, I was looking at the
log force code to see if an async CIL push could be done instead.
This lead me to xfs_log_force_lsn() and looking at how it works.
xfs_log_force_lsn() is only called from inode synchronisation
contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn
value as the LSN to sync the log to. This gets passed to
xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the
journal, and then used by xfs_log_force_lsn() to flush the iclogs to
the journal.
The problem is that ip->i_itemp->ili_last_lsn does not store a
log sequence number. What it stores is passed to it from the
->iop_committing method, which is called by xfs_log_commit_cil().
The value this passes to the iop_committing method is the CIL
context sequence number that the item was committed to.
As it turns out, xlog_cil_force_lsn() converts the sequence to an
actual commit LSN for the related context and returns that to
xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn"
variable that contained a sequence with an actual LSN and then uses
that to sync the iclogs.
This caused me some confusion for a while, even though I originally
wrote all this code a decade ago. ->iop_committing is only used by
a couple of log item types, and only inode items use the sequence
number it is passed.
Let's clean up the API, CIL structures and inode log item to call it
a sequence number, and make it clear that the high level code is
using CIL sequence numbers and not on-disk LSNs for integrity
synchronisation purposes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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