Commit graph

4116 commits

Author SHA1 Message Date
Dave Chinner
155cd433b5 Merge branch 'xfs-4.9-log-recovery-fixes' into for-next 2016-10-03 09:56:28 +11:00
Dave Chinner
a1f45e668e Merge branch 'iomap-4.9-dax' into for-next 2016-10-03 09:53:59 +11:00
Dave Chinner
a89b3f97bb Merge branch 'xfs-4.9-delalloc-rework' into for-next 2016-10-03 09:52:51 +11:00
Dave Chinner
79ad576124 Merge branch 'xfs-4.9-reflink-prep' into for-next 2016-10-03 09:52:31 +11:00
Christoph Hellwig
a447d7cd15 xfs: update atime before I/O in xfs_file_dio_aio_read
After the call to __blkdev_direct_IO the final reference to the file
might have been dropped by aio_complete already, and the call to
file_accessed might cause a use after free.

Instead update the access time before the I/O, similar to how we
update the time stamps before writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-and-tested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-03 09:47:34 +11:00
Brian Foster
5cd9cee98b xfs: log recovery tracepoints to track current lsn and buffer submission
Log recovery has particular rules around buffer submission along with
tricky corner cases where independent transactions can share an LSN. As
such, it can be difficult to follow when/why buffers are submitted
during recovery.

Add a couple tracepoints to post the current LSN of a record when a new
record is being processed and when a buffer is being skipped due to LSN
ordering. Also, update the recover item class to include the LSN of the
current transaction for the item being processed.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:34:52 +10:00
Brian Foster
60a4a22251 xfs: update metadata LSN in buffers during log recovery
Log recovery is currently broken for v5 superblocks in that it never
updates the metadata LSN of buffers written out during recovery. The
metadata LSN is recorded in various bits of metadata to provide recovery
ordering criteria that prevents transient corruption states reported by
buffer write verifiers. Without such ordering logic, buffer updates can
be replayed out of order and lead to false positive transient corruption
states. This is generally not a corruption vector on its own, but
corruption detection shuts down the filesystem and ultimately prevents a
mount if it occurs during log recovery. This requires an xfs_repair run
that clears the log and potentially loses filesystem updates.

This problem is avoided in most cases as metadata writes during normal
filesystem operation update the metadata LSN appropriately. The problem
with log recovery not updating metadata LSNs manifests if the system
happens to crash shortly after log recovery itself. In this scenario, it
is possible for log recovery to complete all metadata I/O such that the
filesystem is consistent. If a crash occurs after that point but before
the log tail is pushed forward by subsequent operations, however, the
next mount performs the same log recovery over again. If a buffer is
updated multiple times in the dirty range of the log, an earlier update
in the log might not be valid based on the current state of the
associated buffer after all of the updates in the log had been replayed
(before the previous crash). If a verifier happens to detect such a
problem, the filesystem claims corruption and immediately shuts down.

This commonly manifests in practice as directory block verifier failures
such as the following, likely due to directory verifiers being
particularly detailed in their checks as compared to most others:

  ...
  Mounting V5 Filesystem
  XFS (dm-0): Starting recovery (logdev: internal)
  XFS (dm-0): Internal error XFS_WANT_CORRUPTED_RETURN at line ... of \
    file fs/xfs/libxfs/xfs_dir2_data.c.  Caller xfs_dir3_data_verify ...
  ...

Update log recovery to update the metadata LSN of recovered buffers.
Since metadata LSNs are already updated by write verifer functions via
attached log items, attach a dummy log item to the buffer during
validation and explicitly set the LSN of the current transaction. This
ensures that the metadata LSN of a buffer is updated based on whether
the recovery I/O actually completes, and if so, that subsequent recovery
attempts identify that the buffer is already up to date with respect to
the current transaction.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:34:27 +10:00
Brian Foster
040c52c0aa xfs: don't warn on buffers not being recovered due to LSN
The log recovery buffer validation function is invoked in cases where a
buffer update may be skipped due to LSN ordering. If the validation
function happens to come across directory conversion situations (e.g., a
dir3 block to data conversion), it may warn about seeing a buffer log
format of one type and a buffer with a magic number of another.

This warning is not valid as the buffer update is ultimately skipped.
This is indicated by a current_lsn of NULLCOMMITLSN provided by the
caller. As such, update xlog_recover_validate_buf_type() to only warn in
such cases when a buffer update is expected.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:32:50 +10:00
Brian Foster
22db9af248 xfs: pass current lsn to log recovery buffer validation
The current LSN must be available to the buffer validation function to
provide the ability to update the metadata LSN of the buffer. Pass the
current_lsn value down to xlog_recover_validate_buf_type() in
preparation.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:32:07 +10:00
Brian Foster
12818d24db xfs: rework log recovery to submit buffers on LSN boundaries
The fix to log recovery to update the metadata LSN in recovered buffers
introduces the requirement that a buffer is submitted only once per
current LSN. Log recovery currently submits buffers on transaction
boundaries. This is not sufficient as the abstraction between log
records and transactions allows for various scenarios where multiple
transactions can share the same current LSN. If independent transactions
share an LSN and both modify the same buffer, log recovery can
incorrectly skip updates and leave the filesystem in an inconsisent
state.

In preparation for proper metadata LSN updates during log recovery,
update log recovery to submit buffers for write on LSN change boundaries
rather than transaction boundaries. Explicitly track the current LSN in
a new struct xlog field to handle the various corner cases of when the
current LSN may or may not change.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:22:16 +10:00
Dave Chinner
ddeb14f4fb xfs: quiesce the filesystem after recovery on readonly mount
Recently we've had a number of reports where log recovery on a v5
filesystem has reported corruptions that looked to be caused by
recovery being re-run over the top of an already-recovered
metadata. This has uncovered a bug in recovery (fixed elsewhere)
but the vector that caused this was largely unknown.

A kdump test started tripping over this problem - the system
would be crashed, the kdump kernel and environment would boot and
dump the kernel core image, and then the system would reboot. After
reboot, the root filesystem was triggering log recovery and
corruptions were being detected. The metadumps indicated the above
log recovery issue.

What is happening is that the kdump kernel and environment is
mounting the root device read-only to find the binaries needed to do
it's work. The result of this is that it is running log recovery.
However, because there were unlinked files and EFIs to be processed
by recovery, the completion of phase 1 of log recovery could not
mark the log clean. And because it's a read-only mount, the unmount
process does not write records to the log to mark it clean, either.
Hence on the next mount of the filesystem, log recovery was run
again across all the metadata that had already been recovered and
this is what triggered corruption warnings.

To avoid this problem, we need to ensure that a read-only mount
always updates the log when it completes the second phase of
recovery. We already handle this sort of issue with rw->ro remount
transitions, so the solution is as simple as quiescing the
filesystem at the appropriate time during the mount process. This
results in the log being marked clean so the mount behaviour
recorded in the logs on repeated RO mounts will change (i.e. log
recovery will no longer be run on every mount until a RW mount is
done). This is a user visible change in behaviour, but it is
harmless.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:21:44 +10:00
Dave Chinner
292378edcb xfs: remote attribute blocks aren't really userdata
When adding a new remote attribute, we write the attribute to the
new extent before the allocation transaction is committed. This
means we cannot reuse busy extents as that violates crash
consistency semantics. Hence we currently treat remote attribute
extent allocation like userdata because it has the same overwrite
ordering constraints as userdata.

Unfortunately, this also allows the allocator to incorrectly apply
extent size hints to the remote attribute extent allocation. This
results in interesting failures, such as transaction block
reservation overruns and in-memory inode attribute fork corruption.

To fix this, we need to separate the busy extent reuse configuration
from the userdata configuration. This changes the definition of
XFS_BMAPI_METADATA slightly - it now means that allocation is
metadata and reuse of busy extents is acceptible due to the metadata
ordering semantics of the journal. If this flag is not set, it
means the allocation is that has unordered data writeback, and hence
busy extent reuse is not allowed. It no longer implies the
allocation is for user data, just that the data write will not be
strictly ordered. This matches the semantics for both user data
and remote attribute block allocation.

As such, This patch changes the "userdata" field to a "datatype"
field, and adds a "no busy reuse" flag to the field.
When we detect an unordered data extent allocation, we immediately set
the no reuse flag. We then set the "user data" flags based on the
inode fork we are allocating the extent to. Hence we only set
userdata flags on data fork allocations now and consider attribute
fork remote extents to be an unordered metadata extent.

The result is that remote attribute extents now have the expected
allocation semantics, and the data fork allocation behaviour is
completely unchanged.

It should be noted that there may be other ways to fix this (e.g.
use ordered metadata buffers for the remote attribute extent data
write) but they are more invasive and difficult to validate both
from a design and implementation POV. Hence this patch takes the
simple, obvious route to fixing the problem...

Reported-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-26 08:21:28 +10:00
Christoph Hellwig
6c31f495d1 xfs: use iomap to implement DAX
Another users of buffer_heads bytes the dust.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:28:38 +10:00
Christoph Hellwig
e372843a40 xfs: refactor xfs_setfilesize
Rename the current function to __xfs_setfilesize and add a non-static
wrapper that also takes care of creating the transaction.  This new
helper will be used by the new iomap-based DAX path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:26:41 +10:00
Christoph Hellwig
66642c5c1d xfs: take the ilock shared if possible in xfs_file_iomap_begin
We always just read the extent first, and will later lock exlusively
after first dropping the lock in case we actually allocate blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:26:39 +10:00
Christoph Hellwig
17879e8f86 xfs: fix locking for DAX writes
So far DAX writes inherited the locking from direct I/O writes, but
the direct I/O model of using shared locks for writes is actually
wrong for DAX.  For direct I/O we're out of any standards and don't
have to provide the Posix required exclusion between writers, but
for DAX which gets transparently enable on applications without any
knowledge of it we can't simply drop the requirement.  Even worse
this only happens for aligned writes and thus doesn't show up for
many typical use cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:24:50 +10:00
Christoph Hellwig
ecd50729f7 iomap: add IOMAP_F_NEW flag
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:24:37 +10:00
Christoph Hellwig
51446f5ba4 xfs: rewrite and optimize the delalloc write path
Currently xfs_iomap_write_delay does up to lookups in the inode
extent tree, which is rather costly especially with the new iomap
based write path and small write sizes.

But it turns out that the low-level xfs_bmap_search_extents gives us
all the information we need in the regular delalloc buffered write
path:

 - it will return us an extent covering the block we are looking up
   if it exists.  In that case we can simply return that extent to
   the caller and are done
 - it will tell us if we are beyoned the last current allocated
   block with an eof return parameter.  In that case we can create a
   delalloc reservation and use the also returned information about
   the last extent in the file as the hint to size our delalloc
   reservation.
 - it can tell us that we are writing into a hole, but that there is
   an extent beyoned this hole.  In this case we can create a
   delalloc reservation that covers the requested size (possible
   capped to the next existing allocation).

All that can be done in one single routine instead of bouncing up
and down a few layers.  This reduced the CPU overhead of the block
mapping routines and also simplified the code a lot.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:10:21 +10:00
Christoph Hellwig
85a6e764ff xfs: make xfs_inode_set_eofblocks_tag cheaper for the common case
For long growing file writes we will usually already have the
eofblocks tag set when adding more speculative preallocations.  Add
a flag in the inode to allow us to skip the the fairly expensive
AG-wide spinlocks and multiple radix tree operations in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:09:48 +10:00
Christoph Hellwig
f8e3a82575 xfs: factor our a helper to calculate the EOF alignment
And drop the pointless mp argument to xfs_iomap_eof_align_last_fsb,
while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:09:28 +10:00
Christoph Hellwig
e9c4973638 xfs: move xfs_bmbt_to_iomap up
We'll need it earlier in the file soon, so the unchanged function to
the top of xfs_iomap.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:09:12 +10:00
Darrick J. Wong
3fd129b63f xfs: set up per-AG free space reservations
One unfortunate quirk of the reference count and reverse mapping
btrees -- they can expand in size when blocks are written to *other*
allocation groups if, say, one large extent becomes a lot of tiny
extents.  Since we don't want to start throwing errors in the middle
of CoWing, we need to reserve some blocks to handle future expansion.
The transaction block reservation counters aren't sufficient here
because we have to have a reserve of blocks in every AG, not just
somewhere in the filesystem.

Therefore, create two per-AG block reservation pools.  One feeds the
AGFL so that rmapbt expansion always succeeds, and the other feeds all
other metadata so that refcountbt expansion never fails.

Use the count of how many reserved blocks we need to have on hand to
create a virtual reservation in the AG.  Through selective clamping of
the maximum length of allocation requests and of the length of the
longest free extent, we can make it look like there's less free space
in the AG unless the reservation owner is asking for blocks.

In other words, play some accounting tricks in-core to make sure that
we always have blocks available.  On the plus side, there's nothing to
clean up if we crash, which is contrast to the strategy that the rough
draft used (actually removing extents from the freespace btrees).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 10:30:52 +10:00
Darrick J. Wong
385d655861 xfs: defer should allow ->finish_item to request a new transaction
When xfs_defer_finish calls ->finish_item, it's possible that
(refcount) won't be able to finish all the work in a single
transaction.  When this happens, the ->finish_item handler should
shorten the log done item's list count, update the work item to
reflect where work should continue, and return -EAGAIN so that
defer_finish knows to retain the pending item on the pending list,
roll the transaction, and restart processing where we left off.

Plumb in the code and document how this mechanism is supposed to work.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-09-19 10:26:25 +10:00
Darrick J. Wong
c611cc0360 xfs: count the blocks in a btree
Provide a helper method to count the number of blocks in a short form
btree.  The refcount and rmap btrees need to know the number of blocks
already in use to set up their per-AG block reservations during mount.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 10:25:20 +10:00
Darrick J. Wong
4ed3f68792 xfs: create a standard btree size calculator code
Create a helper to generate AG btree height calculator functions.
This will be used (much) later when we get to the refcount btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 10:25:03 +10:00
Darrick J. Wong
a1d46cffaf xfs: remove xfs_btree_bigkey
Remove the xfs_btree_bigkey mess and simply make xfs_btree_key big enough
to hold both keys in-core.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 10:24:36 +10:00
Darrick J. Wong
cd00158ce3 xfs: convert RUI log formats to use variable length arrays
Use variable length array declarations for RUI log items,
and replace the open coded sizeof formulae with a single function.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 10:24:27 +10:00
Eric Sandeen
7716981273 xfs: normalize "infinite" retries in error configs
As it stands today, the "fail immediately" vs. "retry forever"
values for max_retries and retry_timeout_seconds in the xfs metadata
error configurations are not consistent.

A retry_timeout_seconds of 0 means "retry forever," but a
max_retries of 0 means "fail immediately."

retry_timeout_seconds < 0 is disallowed, while max_retries == -1
means "retry forever."

Make this consistent across the error configs, such that a value of
0 means "fail immediately" (i.e. wait 0 seconds, or retry 0 times),
and a value of -1 always means "retry forever."

This makes retry_timeout a signed long to accommodate the -1, even
though it stores jiffies.  Given our limit of a 1 day maximum
timeout, this should be sufficient even at much higher HZ values
than we have available today.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-14 07:51:30 +10:00
Xie XiuQi
79c350e45e xfs: fix signed integer overflow
Use 1U for unsigned int to avoid a overflow warning from UBSAN.

[   31.910858] UBSAN: Undefined behaviour in fs/xfs/xfs_buf_item.c:889:25
[   31.911252] signed integer overflow:
[   31.911478] -2147483648 - 1 cannot be represented in type 'int'
[   31.911846] CPU: 1 PID: 1011 Comm: tuned Tainted: G    B          ---- -------   3.10.0-327.28.3.el7.x86_64 #1
[   31.911857] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 01/07/2011
[   31.911866]  1ffff1004069cd3b 0000000076bec3fd ffff8802034e69a0 ffffffff81ee3140
[   31.911883]  ffff8802034e69b8 ffffffff81ee31fd ffffffffa0ad79e0 ffff8802034e6b20
[   31.911898]  ffffffff81ee46e2 0000002d515470c0 0000000000000001 0000000041b58ab3
[   31.911913] Call Trace:
[   31.911932]  [<ffffffff81ee3140>] dump_stack+0x1e/0x20
[   31.911947]  [<ffffffff81ee31fd>] ubsan_epilogue+0x12/0x55
[   31.911964]  [<ffffffff81ee46e2>] handle_overflow+0x1ba/0x215
[   31.912083]  [<ffffffff81ee4798>] __ubsan_handle_sub_overflow+0x2a/0x31
[   31.912204]  [<ffffffffa08676fb>] xfs_buf_item_log+0x34b/0x3f0 [xfs]
[   31.912314]  [<ffffffffa0880490>] xfs_trans_log_buf+0x120/0x260 [xfs]
[   31.912402]  [<ffffffffa079a890>] xfs_btree_log_recs+0x80/0xc0 [xfs]
[   31.912490]  [<ffffffffa07a29f8>] xfs_btree_delrec+0x11a8/0x2d50 [xfs]
[   31.913589]  [<ffffffffa07a86f9>] xfs_btree_delete+0xc9/0x260 [xfs]
[   31.913762]  [<ffffffffa075b5cf>] xfs_free_ag_extent+0x63f/0xe20 [xfs]
[   31.914339]  [<ffffffffa075ec0f>] xfs_free_extent+0x2af/0x3e0 [xfs]
[   31.914641]  [<ffffffffa0801b2b>] xfs_bmap_finish+0x32b/0x4b0 [xfs]
[   31.914841]  [<ffffffffa083c2e7>] xfs_itruncate_extents+0x3b7/0x740 [xfs]
[   31.915216]  [<ffffffffa08342fa>] xfs_setattr_size+0x60a/0x860 [xfs]
[   31.915471]  [<ffffffffa08345ea>] xfs_vn_setattr+0x9a/0xe0 [xfs]
[   31.915590]  [<ffffffff8149ad38>] notify_change+0x5c8/0x8a0
[   31.915607]  [<ffffffff81450f22>] do_truncate+0x122/0x1d0
[   31.915640]  [<ffffffff8147beee>] do_last+0x15de/0x2c80
[   31.915707]  [<ffffffff8147d777>] path_openat+0x1e7/0xcc0
[   31.915802]  [<ffffffff81480824>] do_filp_open+0xa4/0x160
[   31.915848]  [<ffffffff81453127>] do_sys_open+0x1b7/0x3f0
[   31.915879]  [<ffffffff81453392>] SyS_open+0x32/0x40
[   31.915897]  [<ffffffff81f08989>] system_call_fastpath+0x16/0x1b

[  240.086809] UBSAN: Undefined behaviour in fs/xfs/xfs_buf_item.c:866:34
[  240.086820] signed integer overflow:
[  240.086830] -2147483648 - 1 cannot be represented in type 'int'
[  240.086846] CPU: 1 PID: 12969 Comm: rm Tainted: G    B          ---- -------   3.10.0-327.28.3.el7.x86_64 #1
[  240.086857] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 01/07/2011
[  240.086868]  1ffff10040491def 00000000e2ea59c1 ffff88020248ef40 ffffffff81ee3140
[  240.086885]  ffff88020248ef58 ffffffff81ee31fd ffffffffa0ad79e0 ffff88020248f0c0
[  240.086901]  ffffffff81ee46e2 0000002d02488000 0000000000000001 0000000041b58ab3
[  240.086915] Call Trace:
[  240.086938]  [<ffffffff81ee3140>] dump_stack+0x1e/0x20
[  240.086953]  [<ffffffff81ee31fd>] ubsan_epilogue+0x12/0x55
[  240.086971]  [<ffffffff81ee46e2>] handle_overflow+0x1ba/0x215
...

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-14 07:41:16 +10:00
Artem Savkov
791cc43b36 Make __xfs_xattr_put_listen preperly report errors.
Commit 2a6fba6 "xfs: only return -errno or success from attr ->put_listent"
changes the returnvalue of __xfs_xattr_put_listen to 0 in case when there is
insufficient space in the buffer assuming that setting context->count to -1
would be enough, but all of the ->put_listent callers only check seen_enough.
This results in a failed assertion:
XFS: Assertion failed: context->count >= 0, file: fs/xfs/xfs_xattr.c, line: 175
in insufficient buffer size case.

This is only reproducible with at least 2 xattrs and only when the buffer
gets depleted before the last one.

Furthermore if buffersize is such that it is enough to hold the last xattr's
name, but not enough to hold the sum of preceeding xattr names listxattr won't
fail with ERANGE, but will suceed returning last xattr's name without the
first character. The first character end's up overwriting data stored at
(context->alist - 1).

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-14 07:40:35 +10:00
Eryu Guan
a27f6ef4e6 xfs: undo block reservation correctly in xfs_trans_reserve()
"blocks" should be added back to fdblocks at undo time, not taken
away, i.e. the minus sign should not be used.

This is a regression introduced by commit 0d485ada40 ("xfs: use
generic percpu counters for free block counter"). And it's found by
code inspection, I didn't it in real world, so there's no
reproducer.

Signed-off-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-14 07:39:07 +10:00
Darrick J. Wong
ea78d80866 xfs: track log done items directly in the deferred pending work item
Christoph reports slab corruption when a deferred refcount update
aborts during _defer_finish().  The cause of this was broken log item
state tracking in xfs_defer_pending -- upon an abort,
_defer_trans_abort() will call abort_intent on all intent items,
including the ones that have already had a done item attached.

This is incorrect because each intent item has 2 refcount: the first
is released when the intent item is committed to the log; and the
second is released when the _done_ item is committed to the log, or
by the intent creator if there is no done item.  In other words, once
we log the done item, responsibility for releasing the intent item's
second refcount is transferred to the done item and /must not/ be
performed by anything else.

The dfp_committed flag should have been tracking whether or not we had
a done item so that _defer_trans_abort could decide if it needs to
abort the intent item, but due to a thinko this was not the case.  Rip
it out and track the done item directly so that we do the right thing
w.r.t. intent item freeing.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-30 13:51:39 +10:00
Brian Foster
800b2694f8 xfs: prevent dropping ioend completions during buftarg wait
xfs_wait_buftarg() waits for all pending I/O, drains the ioend
completion workqueue and walks the LRU until all buffers in the cache
have been released. This is traditionally an unmount operation` but the
mechanism is also reused during filesystem freeze.

xfs_wait_buftarg() invokes drain_workqueue() as part of the quiesce,
which is intended more for a shutdown sequence in that it indicates to
the queue that new operations are not expected once the drain has begun.
New work jobs after this point result in a WARN_ON_ONCE() and are
otherwise dropped.

With filesystem freeze, however, read operations are allowed and can
proceed during or after the workqueue drain. If such a read occurs
during the drain sequence, the workqueue infrastructure complains about
the queued ioend completion work item and drops it on the floor. As a
result, the buffer remains on the LRU and the freeze never completes.

Despite the fact that the overall buffer cache cleanup is not necessary
during freeze, fix up this operation such that it is safe to invoke
during non-unmount quiesce operations. Replace the drain_workqueue()
call with flush_workqueue(), which runs a similar serialization on
pending workqueue jobs without causing new jobs to be dropped. This is
safe for unmount as unmount independently locks out new operations by
the time xfs_wait_buftarg() is invoked.

cc: <stable@vger.kernel.org>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 16:01:59 +10:00
Dave Chinner
f3d7ebdeb2 xfs: fix superblock inprogress check
From inspection, the superblock sb_inprogress check is done in the
verifier and triggered only for the primary superblock via a
"bp->b_bn == XFS_SB_DADDR" check.

Unfortunately, the primary superblock is an uncached buffer, and
hence it is configured by xfs_buf_read_uncached() with:

	bp->b_bn = XFS_BUF_DADDR_NULL;  /* always null for uncached buffers */

And so this check never triggers. Fix it.

cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 16:01:30 +10:00
Darrick J. Wong
5b5c2dbd3c xfs: simple btree query range should look right if LE lookup fails
If the initial LOOKUP_LE in the simple query range fails to find
anything, we should attempt to increment the btree cursor to see
if there actually /are/ records for what we're trying to find.
Without this patch, a bnobt range query of (0, $agsize) returns
no results because the leftmost record never has a startblock
of zero.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 16:00:10 +10:00
Darrick J. Wong
722278997b xfs: fix some key handling problems in _btree_simple_query_range
We only need the record's high key for the first record that we look
at; for all records, we /definitely/ need the regular record key.
Therefore, fix how the simple range query function gets its keys.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 15:59:50 +10:00
Darrick J. Wong
da1f039d69 xfs: don't log the entire end of the AGF
When we're logging the last non-spare field in the AGF, we don't
need to log the spare fields, so plumb in a new AGF logging flag
to help us avoid that.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 15:59:31 +10:00
Darrick J. Wong
738f57c16a xfs: disallow mounting of realtime + rmap filesystems
Since the kernel doesn't currently support the realtime rmapbt,
don't allow such filesystems to be mounted.  Support will appear
in a future release.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 15:59:19 +10:00
Darrick J. Wong
ed150e1a5c xfs: don't perform lookups on zero-height btrees
If the caller passes in a cursor to a zero-height btree (which is
impossible), we never set block to anything but NULL, which causes the
later dereference of it to crash.  Instead, just return -EFSCORRUPTED.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26 15:58:40 +10:00
Dave Chinner
32438cf9d5 Merge branch 'iomap-fixes-4.8-rc3' into for-next 2016-08-17 11:13:37 +10:00
Darrick J. Wong
a03f1a6633 xfs: remove OWN_AG rmap when allocating a block from the AGFL
When we're really tight on space, xfs_alloc_ag_vextent_small() can
allocate a block from the AGFL and give it to the caller.  Since the
caller is never the AGFL-fixing method, we must remove the OWN_AG
reverse mapping because it will clash with whatever rmap the caller
wants to set up.  This bug was discovered by running generic/299
repeatedly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 11:12:57 +10:00
Christoph Hellwig
1d4795e7bd xfs: (re-)implement FIEMAP_FLAG_XATTR
Use a special read-only iomap_ops implementation to support fiemap on
the attr fork.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:45:30 +10:00
Christoph Hellwig
b95a21271b xfs: simplify xfs_file_iomap_begin
We'll never get nimap == 0 for a successful return from xfs_bmapi_read,
so don't try to handle it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:44:52 +10:00
Darrick J. Wong
f32866fdc9 xfs: store rmapbt block count in the AGF
Track the number of blocks used for the rmapbt in the AGF.  When we
get to the AG reservation code we need this counter to quickly
make our reservation during mount.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:31:49 +10:00
Dave Chinner
8b2180b3bf xfs: don't invalidate whole file on DAX read/write
When we do DAX IO, we try to invalidate the entire page cache held
on the file. This is incorrect as it will trash the entire mapping
tree that now tracks dirty state in exceptional entries in the radix
tree slots.

What we are trying to do is remove cached pages (e.g from reads
into holes) that sit in the radix tree over the range we are about
to write to. Hence we should just limit the invalidation to the
range we are about to overwrite.

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:31:33 +10:00
Christoph Hellwig
0af32fb468 xfs: fix bogus space reservation in xfs_iomap_write_allocate
The space reservations was without an explaination in commit

    "Add error reporting calls in error paths that return EFSCORRUPTED"

back in 2003.  There is no reason to reserve disk blocks in the
transaction when allocating blocks for delalloc space as we already
reserved the space when creating the delalloc extent.

With this fix we stop running out of the reserved pool in
generic/229, which has happened for long time with small blocksize
file systems, and has increased in severity with the new buffered
write path.

[ dchinner: we still need to pass the block reservation into
  xfs_bmapi_write() to ensure we don't deadlock during AG selection.
  See commit dbd5c8c ("xfs: pass total block res. as total
  xfs_bmapi_write() parameter") for more details on why this is
  necessary. ]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:30:28 +10:00
Brian Foster
4dd3fd7197 xfs: don't assert fail on non-async buffers on ioacct decrement
The buffer I/O accounting mechanism tracks async buffers under I/O.  As
an optimization, the buffer I/O count is incremented only once on the
first async I/O for a given hold cycle of a buffer and decremented once
the buffer is released to the LRU (or freed).

xfs_buf_ioacct_dec() has an ASSERT() check for an XBF_ASYNC buffer, but
we have one or two corner cases where a buffer can be submitted for I/O
multiple times via different methods in a single hold cycle. If an async
I/O occurs first, the I/O count is incremented. If a sync I/O occurs
before the hold count drops, XBF_ASYNC is cleared by the time the I/O
count is decremented.

Remove the async assert check from xfs_buf_ioacct_dec() as this is a
perfectly valid scenario. For the purposes of I/O accounting, we really
only care about the buffer async state at I/O submission time.

Discovered-and-analyzed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:30:28 +10:00
Eryu Guan
337684a174 fs: return EPERM on immutable inode
In most cases, EPERM is returned on immutable inode, and there're only a
few places returning EACCES. I noticed this when running LTP on
overlayfs, setxattr03 failed due to unexpected EACCES on immutable
inode.

So converting all EACCES to EPERM on immutable inode.

Acked-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-07 10:03:31 -04:00
Linus Torvalds
0cbbc422d5 xfs: reverse block mapping support for 4.8-rc1
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Merge tag 'xfs-rmap-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull more xfs updates from Dave Chinner:
 "This is the second part of the XFS updates for this merge cycle, and
  contains the new reverse block mapping feature for XFS.

  Reverse mapping allows us to track the owner of a specific block on
  disk precisely.  It is implemented as a set of btrees (one per
  allocation group) that track the owners of allocated extents.
  Effectively it is a "used space tree" that is updated when we allocate
  or free extents.  i.e. it is coherent with the free space btrees we
  already maintain and never overlaps with them.

  This reverse mapping infrastructure is the building block of several
  upcoming features - reflink, copy-on-write data, dedupe, online
  metadata and data scrubbing, highly accurate bad sector/data loss
  reporting to users, and significantly improved reconstruction of
  damaged and corrupted filesystems.  There's a lot of new stuff coming
  along in the next couple of cycles,a nd it all builds in the rmap
  infrastructure.

  As such, it's a huge chunk of new code with new on-disk format
  features and internal infrastructure.  It warns at mount time as an
  experimental feature and that it may eat data (as we do with all new
  on-disk features until they stabilise).  We have not released
  userspace suport for it yet - userspace support currently requires
  download from Darrick's xfsprogs repo and build from source, so the
  access to this feature is really developer/tester only at this point.
  Initial userspace support will be released at the same time kernel
  with this code in it is released.

  The new rmap enabled code regresses 3 xfstests - all are ENOSPC
  related corner cases, one of which Darrick posted a fix for a few
  hours ago.  The other two are fixed by infrastructure that is part of
  the upcoming reflink patchset.  This new ENOSPC infrastructure
  requires a on-disk format tweak required to keep mount times in
  check - we need to keep an on-disk count of allocated rmapbt blocks so
  we don't have to scan the entire btrees at mount time to count them.

  This is currently being tested and will be part of the fixes sent in
  the next week or two so users will not be exposed to this change"

* tag 'xfs-rmap-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (52 commits)
  xfs: move (and rename) the deferred bmap-free tracepoints
  xfs: collapse single use static functions
  xfs: remove unnecessary parentheses from log redo item recovery functions
  xfs: remove the extents array from the rmap update done log item
  xfs: in btree_lshift, only allocate temporary cursor when needed
  xfs: remove unnecesary lshift/rshift key initialization
  xfs: remove the get*keys and update_keys btree ops pointers
  xfs: enable the rmap btree functionality
  xfs: don't update rmapbt when fixing agfl
  xfs: disable XFS_IOC_SWAPEXT when rmap btree is enabled
  xfs: add rmap btree block detection to log recovery
  xfs: add rmap btree geometry feature flag
  xfs: propagate bmap updates to rmapbt
  xfs: enable the xfs_defer mechanism to process rmaps to update
  xfs: log rmap intent items
  xfs: create rmap update intent log items
  xfs: add rmap btree insert and delete helpers
  xfs: convert unwritten status of reverse mappings
  xfs: remove an extent from the rmap btree
  xfs: add an extent to the rmap btree
  ...
2016-08-06 09:50:36 -04:00
Linus Torvalds
a71e36045e Highlights:
Trond made a change to the server's tcp logic that allows a fast
 	client to better take advantage of high bandwidth networks, but
 	may increase the risk that a single client could starve other
 	clients; a new sunrpc.svc_rpc_per_connection_limit parameter
 	should help mitigate this in the (hopefully unlikely) event this
 	becomes a problem in practice.
 
 	Tom Haynes added a minimal flex-layout pnfs server, which is of
 	no use in production for now--don't build it unless you're doing
 	client testing or further server development.
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Merge tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Trond made a change to the server's tcp logic that allows a fast
     client to better take advantage of high bandwidth networks, but may
     increase the risk that a single client could starve other clients;
     a new sunrpc.svc_rpc_per_connection_limit parameter should help
     mitigate this in the (hopefully unlikely) event this becomes a
     problem in practice.

   - Tom Haynes added a minimal flex-layout pnfs server, which is of no
     use in production for now--don't build it unless you're doing
     client testing or further server development"

* tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd: remove some dead code in nfsd_create_locked()
  nfsd: drop unnecessary MAY_EXEC check from create
  nfsd: clean up bad-type check in nfsd_create_locked
  nfsd: remove unnecessary positive-dentry check
  nfsd: reorganize nfsd_create
  nfsd: check d_can_lookup in fh_verify of directories
  nfsd: remove redundant zero-length check from create
  nfsd: Make creates return EEXIST instead of EACCES
  SUNRPC: Detect immediate closure of accepted sockets
  SUNRPC: accept() may return sockets that are still in SYN_RECV
  nfsd: allow nfsd to advertise multiple layout types
  nfsd: Close race between nfsd4_release_lockowner and nfsd4_lock
  nfsd/blocklayout: Make sure calculate signature/designator length aligned
  xfs: abstract block export operations from nfsd layouts
  SUNRPC: Remove unused callback xpo_adjust_wspace()
  SUNRPC: Change TCP socket space reservation
  SUNRPC: Add a server side per-connection limit
  SUNRPC: Micro optimisation for svc_data_ready
  SUNRPC: Call the default socket callbacks instead of open coding
  SUNRPC: lock the socket while detaching it
  ...
2016-08-04 19:59:06 -04:00