Commit Graph

857 Commits

Author SHA1 Message Date
Darrick J. Wong e1f6ca1138 xfs: rename m_inotbt_nores to m_finobt_nores
Rename this flag variable to imply more strongly that it's related to
the free inode btree (finobt) operation.  No functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-02-14 22:42:57 -08:00
Darrick J. Wong 4260baac62 xfs: add magic numbers to dquot buffer ops
Add dquot magic numbers to the buffer ops type, in case we ever want to
use them.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:07:01 -08:00
Darrick J. Wong 2bfe7069f7 xfs: add inode magic to inode verifier
Use xfs_verify_magic to check the magic numbers of inodes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:07:01 -08:00
Brian Foster 8764f98351 xfs: factor xfs_da3_blkinfo verification into common helper
With the verifier magic value helper in place, we've left a bit more
duplicate code across the verifiers that involve struct
xfs_da3_blkinfo. This includes the da node, xattr leaf and dir leaf
verifiers, all of which perform similar checks for v4 and v5
filesystems.

Create a common helper to verify an xfs_da3_blkinfo structure,
taking care to only access v5 fields where appropriate, and refactor
the aforementioned verifiers to use the helper. No functional
changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 39708c20ab xfs: miscellaneous verifier magic value fixups
Most buffer verifiers have hardcoded magic value checks
conditionalized on the version of the filesystem. The magic value
field of the verifier structure facilitates abstraction of some of
this code. Populate the ->magic field of various verifiers to take
advantage of this abstraction. No functional changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 09f420197d xfs: use verifier magic field in dir2 leaf verifiers
The dir2 leaf verifiers share the same underlying structure
verification code, but implement six accessor functions to multiplex
the code across the two verifiers. Further, the magic value isn't
sufficiently abstracted such that the common helper has to manually
fix up the magic from the caller on v5 filesystems.

Use the magic field in the verifier structure to eliminate the
duplicate code and clean this all up. No functional change.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster b8f8980166 xfs: distinguish between bnobt and cntbt magic values
The allocation btree verifiers share code that is unable to detect
cross-tree magic value corruptions such as a bnobt block with a
cntbt magic value. Populate the b_ops->magic field of the associated
verifier structures such that the structure verifier can check the
magic value against the expected value based on tree type.

The btree level check requires knowledge of the tree type to
determine the appropriate maximum value. This was previously part of
the hardcoded magic value checks. With that code removed, peek at
the first magic value in the verifier to determine the expected tree
type of the current block.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 27df4f5045 xfs: split up allocation btree verifier
Similar to the inode btree verifier, the same allocation btree
verifier structure is shared between the by-bno (bnobt) and by-size
(cntbt) btrees. This prevents the ability to distinguish magic
values between them. Separate the verifier into two, one for each
tree, and assign them appropriately. No functional changes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 8473fee340 xfs: distinguish between inobt and finobt magic values
The inode btree verifier code is shared between the inode btree and
free inode btree because the underlying metadata formats are
essentially equivalent. A side effect of this is that the verifier
cannot determine whether a particular btree block should have an
inobt or finobt magic value.

This logic allows an unfortunate xfs_repair bug to escape detection
where certain level > 0 nodes of the finobt are stamped with inobt
magic by xfs_repair finobt reconstruction. This is fortunately not a
severe problem since the inode btree magic values do not contribute
to any changes in kernel behavior, but we do need a means to detect
and prevent this problem in the future.

Add a field to xfs_buf_ops to store the v4 and v5 superblock magic
values expected by a particular verifier. Add a helper to check an
on-disk magic value against the value expected by the verifier. Call
the helper from the shared [f]inobt verifier code for magic value
verification. This ensures that the inode btree blocks each have the
appropriate magic value based on specific tree type and superblock
version.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 01e68f40bf xfs: create a separate finobt verifier
The inobt verifier is reused for the inobt and finobt, which
prevents the ability to distinguish between magic values on a
per-tree basis. Create a separate finobt structure in preparation
for changes to enforce the appropriate magic value for the
associated tree. This patch has no functional change.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster e34d3e74eb xfs: always check magic values in on-disk byte order
Most verifiers that check on-disk magic values convert the CPU
endian magic value constant to disk endian to facilitate compile
time optimization of the byte swap and reduce the need for runtime
byte swaps in buffer verifiers. Several buffer verifiers do not
follow this pattern. Update those verifiers for consistency.

Also fix up a random typo in the inode readahead verifier name.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Darrick J. Wong 9b24717979 xfs: cache unlinked pointers in an rhashtable
Use a rhashtable to cache the unlinked list incore.  This should speed
up unlinked processing considerably when there are a lot of inodes on
the unlinked list because iunlink_remove no longer has to traverse an
entire bucket list to find which inode points to the one being removed.

The incore list structure records "X.next_unlinked = Y" relations, with
the rhashtable using Y to index the records.  This makes finding the
inode X that points to a inode Y very quick.  If our cache fails to find
anything we can always fall back on the old method.

FWIW this drastically reduces the amount of time it takes to remove
inodes from the unlinked list.  I wrote a program to open a lot of
O_TMPFILE files and then close them in the same order, which takes
a very long time if we have to traverse the unlinked lists.  With the
ptach, I see:

+ /d/t/tmpfile/tmpfile
Opened 193531 files in 6.33s.
Closed 193531 files in 5.86s

real    0m12.192s
user    0m0.064s
sys     0m11.619s
+ cd /
+ umount /mnt

real    0m0.050s
user    0m0.004s
sys     0m0.030s

And without the patch:

+ /d/t/tmpfile/tmpfile
Opened 193588 files in 6.35s.
Closed 193588 files in 751.61s

real    12m38.853s
user    0m0.084s
sys     12m34.470s
+ cd /
+ umount /mnt

real    0m0.086s
user    0m0.000s
sys     0m0.060s

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:07:01 -08:00
Darrick J. Wong 7d36c19538 xfs: add xfs_verify_agino_or_null helper
Add a new helper to check that a per-AG inode pointer is either null or
points somewhere valid within that AG.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-02-11 16:07:01 -08:00
Brian Foster c2b3164320 xfs: use the latest extent at writeback delalloc conversion time
The writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping outside of the current
page. This is because the ilock is cycled between the time the
caller originally looked up the mapping and across each real
allocation of the provided file range. This code has collected
various hacks over the years to help combat the symptoms of these
races (i.e., truncate race detection, allocation into hole
detection, etc.), but none address the fundamental problem that the
imap may not be valid at allocation time.

Rather than continue to use race detection hacks, update writeback
delalloc conversion to a model that explicitly converts the delalloc
extent backing the current file offset being processed. The current
file offset is the only block we can trust to remain once the ilock
is dropped because any operation that can remove the block
(truncate, hole punch, etc.) must flush and discard pagecache pages
first.

Modify xfs_iomap_write_allocate() to use the xfs_bmapi_delalloc()
mechanism to request allocation of the entire delalloc extent
backing the current offset instead of assuming the extent passed by
the caller is unchanged. Record the range specified by the caller
and apply it to the resulting allocated extent so previous checks by
the caller for COW fork overlap are not lost. Finally, overload the
bmapi delalloc flag with the range reval flag behavior since this is
the only use case for both.

This ensures that writeback always picks up the correct
and current extent associated with the page, regardless of races
with other extent modifying operations. If operating on a data fork
and the COW overlap state has changed since the ilock was cycled,
the caller revalidates against the COW fork sequence number before
using the imap for the next block.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 627209fbcc xfs: create delalloc bmapi wrapper for full extent allocation
The writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping. This stems from the
fact that the bmapi allocation code requires a file range to
allocate and the writeback conversion code assumes the range of the
currently cached mapping is still valid with respect to the fork. It
may not be valid, however, because the ilock is cycled (potentially
multiple times) between the time the cached mapping was populated
and the delalloc conversion occurs.

To facilitate a solution to this problem, create a new
xfs_bmapi_delalloc() wrapper to xfs_bmapi_write() that takes a file
(FSB) offset and attempts to allocate whatever delalloc extent backs
the offset. Use a new bmapi flag to cause xfs_bmapi_write() to set
the range based on the extent backing the bno parameter unless bno
lands in a hole. If bno does land in a hole, fall back to the
current behavior (which may result in an error or quietly skipping
holes in the specified range depending on other parameters). This
patch does not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 3b35089807 xfs: remove superfluous writeback mapping eof trimming
Now that the cached writeback mapping is explicitly invalidated on
data fork changes, the EOF trimming band-aid is no longer necessary.
Remove xfs_trim_extent_eof() as well since it has no other users.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
Brian Foster 9f9bc034b8 xfs: update fork seq counter on data fork changes
The sequence counter in the xfs_ifork structure is only updated on
COW forks. This is because the counter is currently only used to
optimize out repetitive COW fork checks at writeback time.

Tweak the extent code to update the seq counter regardless of the
fork type in preparation for using this counter on data forks as
well.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:00 -08:00
Darrick J. Wong 654805367d xfs: check attribute name validity
Check extended attribute entry names for invalid characters.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:06:40 -08:00
Darrick J. Wong e5d7d51b34 xfs: check directory name validity
Check directory entry names for invalid characters.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:06:40 -08:00
Darrick J. Wong f8c1d7023e xfs: scrub should flag dir/attr offsets that aren't mappable with xfs_dablk_t
Teach scrub to flag extent maps that exceed the range that can be mapped
with a xfs_dablk_t.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:06:40 -08:00
Darrick J. Wong 86d163dbfe xfs: stringify scrub types in ftrace output
Use __print_symbolic to print the scrub type in ftrace output.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-12-19 14:02:01 -08:00
Darrick J. Wong c494213f30 xfs: stringify btree cursor types in ftrace output
Use __print_symbolic to print the btree type in ftrace output.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-12-19 14:02:01 -08:00
Darrick J. Wong 0357d21a6c xfs: move XFS_INODE_FORMAT_STR mappings to libxfs
Move XFS_INODE_FORMAT_STR to libxfs so that we don't forget to keep it
updated, and add necessary TRACE_DEFINE_ENUM.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-12-19 14:02:01 -08:00
Darrick J. Wong 05c753c4cf xfs: move XFS_AG_BTREE_CMP_FORMAT_STR mappings to libxfs
Move XFS_AG_BTREE_CMP_FORMAT_STR to libxfs so that we don't forget to
keep it updated, and TRACE_DEFINE_ENUM the values while we're at it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-12-19 14:02:01 -08:00
Darrick J. Wong 85f8dff00a xfs: fix symbolic enum printing in ftrace output
ftrace's __print_symbolic() has a (very poorly documented) requirement
that any enum values used in the symbol to string translation table be
wrapped in a TRACE_DEFINE_ENUM so that the enum value can be encoded in
the ftrace ring buffer.  Fix this unsatisfied requirement.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-12-19 14:02:01 -08:00
Omar Sandoval 355e353213 xfs: cache minimum realtime summary level
The realtime summary is a two-dimensional array on disk, effectively:

u32 rsum[log2(number of realtime extents) + 1][number of blocks in the bitmap]

rsum[log][bbno] is the number of extents of size 2**log which start in
bitmap block bbno.

xfs_rtallocate_extent_near() uses xfs_rtany_summary() to check whether
rsum[log][bbno] != 0 for any log level. However, the summary array is
stored in row-major order (i.e., like an array in C), so all of these
entries are not adjacent, but rather spread across the entire summary
file. In the worst case (a full bitmap block), xfs_rtany_summary() has
to check every level.

This means that on a moderately-used realtime device, an allocation will
waste a lot of time finding, reading, and releasing buffers for the
realtime summary. In particular, one of our storage services (which runs
on servers with 8 very slow CPUs and 15 8 TB XFS realtime filesystems)
spends almost 5% of its CPU cycles in xfs_rtbuf_get() and
xfs_trans_brelse() called from xfs_rtany_summary().

One solution would be to also store the summary with the dimensions
swapped. However, this would require a disk format change to a very old
component of XFS.

Instead, we can cache the minimum size which contains any extents. We do
so lazily; rather than guaranteeing that the cache contains the precise
minimum, it always contains a loose lower bound which we tighten when we
read or update a summary block. This only uses a few kilobytes of memory
and is already serialized via the realtime bitmap and summary inode
locks, so the cost is minimal. With this change, the same workload only
spends 0.2% of its CPU cycles in the realtime allocator.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-12-12 08:47:17 -08:00
Darrick J. Wong c1b4a321ed xfs: precalculate cluster alignment in inodes and blocks
Store the inode cluster alignment information in units of inodes and
blocks in the mount data so that we don't have to keep recalculating
them.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:17 -08:00
Darrick J. Wong 83dcdb4469 xfs: precalculate inodes and blocks per inode cluster
Store the number of inodes and blocks per inode cluster in the mount
data so that we don't have to keep recalculating them.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:17 -08:00
Darrick J. Wong 43004b2a8d xfs: add a block to inode count converter
Add new helpers to convert units of fs blocks into inodes, and AG blocks
into AG inodes, respectively.  Convert all the open-coded conversions
and XFS_OFFBNO_TO_AGINO(, , 0) calls to use them, as appropriate.  The
OFFBNO_TO_AGINO macro is retained for xfs_repair.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:16 -08:00
Darrick J. Wong 7280fedaf3 xfs: remove xfs_rmap_ag_owner and friends
Owner information for static fs metadata can be defined readonly at
build time because it never changes across filesystems.  This enables us
to reduce stack usage (particularly in scrub) because we can use the
statically defined oinfo structures.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:16 -08:00
Darrick J. Wong 66e3237e72 xfs: const-ify xfs_owner_info arguments
Only certain functions actually change the contents of an
xfs_owner_info; the rest can accept a const struct pointer.  This will
enable us to save stack space by hoisting static owner info types to
be const global variables.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:16 -08:00
Darrick J. Wong 02b100fb83 xfs: streamline defer op type handling
There's no need to bundle a pointer to the defer op type into the defer
op control structure.  Instead, store the defer op type enum, which
enables us to shorten some of the lines.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:16 -08:00
Darrick J. Wong bc9f2b7c8a xfs: idiotproof defer op type configuration
Recently, we forgot to port a new defer op type to xfsprogs, which
caused us some userspace pain.  Reorganize the way we make libxfs
clients supply defer op type information so that all type information
has to be provided at build time instead of risky runtime dynamic
configuration.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2018-12-12 08:47:16 -08:00
Dave Chinner 43feeea88c xfs: zero length symlinks are not valid
A log recovery failure has been reproduced where a symlink inode has
a zero length in extent form. It was caused by a shutdown during a
combined fstress+fsmark workload.

The underlying problem is the issue in xfs_inactive_symlink(): the
inode is unlocked between the symlink inactivation/truncation and
the inode being freed. This opens a window for the inode to be
written to disk before it xfs_ifree() removes it from the unlinked
list, marks it free in the inobt and zeros the mode.

For shortform inodes, the fix is simple. xfs_ifree() clears the data
fork state, so there's no need to do it in xfs_inactive_symlink().
This means the shortform fork verifier will not see a zero length
data fork as it mirrors the inode size through to xfs_ifree()), and
hence if the inode gets written back and the fork verifiers are run
they will still see a fork that matches the on-disk inode size.

For extent form (remote) symlinks, it is a little more tricky. Here
we explicitly set the inode size to zero, so the above race can lead
to zero length symlinks on disk. Because the inode is unlinked at
this point (i.e. on the unlinked list) and unreferenced, it can
never be seen again by a user. Hence when we set the inode size to
zeor, also change the type to S_IFREG. xfs_ifree() expects S_IFREG
inodes to be of zero length, and so this avoids all the problems of
zero length symlinks ever hitting the disk. It also avoids the
problem of needing to handle zero length symlink inodes in log
recovery to replay the extent free intents and the remaining
deferops to free the extents the symlink used.

Also add a couple of asserts to warn us if zero length symlinks end
up in either the symlink create or inactivation paths.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-12-12 08:47:15 -08:00
Pan Bian fe5ed6c22e xfs: libxfs: move xfs_perag_put late
The function xfs_alloc_get_freelist calls xfs_perag_put to drop the
reference. However, pag->pagf_btreeblks is read and written after the
put operation. This patch moves the put operation later.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
[darrick: minor changelog edits]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-12-12 08:46:20 -08:00
Eric Sandeen 7d048df4e9 xfs: fix inverted return from xfs_btree_sblock_verify_crc
xfs_btree_sblock_verify_crc is a bool so should not be returning
a failaddr_t; worse, if xfs_log_check_lsn fails it returns
__this_address which looks like a boolean true (i.e. success)
to the caller.

(interestingly xfs_btree_lblock_verify_crc doesn't have the issue)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-12-04 08:50:49 -08:00
Dave Chinner 9230a0b65b xfs: delalloc -> unwritten COW fork allocation can go wrong
Long saga. There have been days spent following this through dead end
after dead end in multi-GB event traces. This morning, after writing
a trace-cmd wrapper that enabled me to be more selective about XFS
trace points, I discovered that I could get just enough essential
tracepoints enabled that there was a 50:50 chance the fsx config
would fail at ~115k ops. If it didn't fail at op 115547, I stopped
fsx at op 115548 anyway.

That gave me two traces - one where the problem manifested, and one
where it didn't. After refining the traces to have the necessary
information, I found that in the failing case there was a real
extent in the COW fork compared to an unwritten extent in the
working case.

Walking back through the two traces to the point where the CWO fork
extents actually diverged, I found that the bad case had an extra
unwritten extent in it. This is likely because the bug it led me to
had triggered multiple times in those 115k ops, leaving stray
COW extents around. What I saw was a COW delalloc conversion to an
unwritten extent (as they should always be through
xfs_iomap_write_allocate()) resulted in a /written extent/:

xfs_writepage:        dev 259:0 ino 0x83 pgoff 0x17000 size 0x79a00 offset 0 length 0
xfs_iext_remove:      dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/2 offset 32 block 152 count 20 flag 1 caller xfs_bmap_add_extent_delay_real
xfs_bmap_pre_update:  dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/1 offset 1 block 4503599627239429 count 31 flag 0 caller xfs_bmap_add_extent_delay_real
xfs_bmap_post_update: dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/1 offset 1 block 121 count 51 flag 0 caller xfs_bmap_add_ex

Basically, Cow fork before:

	0 1            32          52
	+H+DDDDDDDDDDDD+UUUUUUUUUUU+
	   PREV		RIGHT

COW delalloc conversion allocates:

	  1	       32
	  +uuuuuuuuuuuu+
	  NEW

And the result according to the xfs_bmap_post_update trace was:

	0 1            32          52
	+H+wwwwwwwwwwwwwwwwwwwwwwww+
	   PREV

Which is clearly wrong - it should be a merged unwritten extent,
not an unwritten extent.

That lead me to look at the LEFT_FILLING|RIGHT_FILLING|RIGHT_CONTIG
case in xfs_bmap_add_extent_delay_real(), and sure enough, there's
the bug.

It takes the old delalloc extent (PREV) and adds the length of the
RIGHT extent to it, takes the start block from NEW, removes the
RIGHT extent and then updates PREV with the new extent.

What it fails to do is update PREV.br_state. For delalloc, this is
always XFS_EXT_NORM, while in this case we are converting the
delayed allocation to unwritten, so it needs to be updated to
XFS_EXT_UNWRITTEN. This LF|RF|RC case does not do this, and so
the resultant extent is always written.

And that's the bug I've been chasing for a week - a bmap btree bug,
not a reflink/dedupe/copy_file_range bug, but a BMBT bug introduced
with the recent in core extent tree scalability enhancements.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-21 10:10:53 -08:00
Dave Chinner c08768977b xfs: finobt AG reserves don't consider last AG can be a runt
The last AG may be very small comapred to all other AGs, and hence
AG reservations based on the superblock AG size may actually consume
more space than the AG actually has. This results on assert failures
like:

XFS: Assertion failed: xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= pag->pagf_freeblks + pag->pagf_flcount, file: fs/xfs/libxfs/xfs_ag_resv.c, line: 319
[   48.932891]  xfs_ag_resv_init+0x1bd/0x1d0
[   48.933853]  xfs_fs_reserve_ag_blocks+0x37/0xb0
[   48.934939]  xfs_mountfs+0x5b3/0x920
[   48.935804]  xfs_fs_fill_super+0x462/0x640
[   48.936784]  ? xfs_test_remount_options+0x60/0x60
[   48.937908]  mount_bdev+0x178/0x1b0
[   48.938751]  mount_fs+0x36/0x170
[   48.939533]  vfs_kern_mount.part.43+0x54/0x130
[   48.940596]  do_mount+0x20e/0xcb0
[   48.941396]  ? memdup_user+0x3e/0x70
[   48.942249]  ksys_mount+0xba/0xd0
[   48.943046]  __x64_sys_mount+0x21/0x30
[   48.943953]  do_syscall_64+0x54/0x170
[   48.944835]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Hence we need to ensure the finobt per-ag space reservations take
into account the size of the last AG rather than treat it like all
the other full size AGs.

Note that both refcountbt and rmapbt already take the size of the AG
into account via reading the AGF length directly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-20 10:36:11 -08:00
Dave Chinner 837514f7a4 xfs: fix overflow in xfs_attr3_leaf_verify
generic/070 on 64k block size filesystems is failing with a verifier
corruption on writeback or an attribute leaf block:

[   94.973083] XFS (pmem0): Metadata corruption detected at xfs_attr3_leaf_verify+0x246/0x260, xfs_attr3_leaf block 0x811480
[   94.975623] XFS (pmem0): Unmount and run xfs_repair
[   94.976720] XFS (pmem0): First 128 bytes of corrupted metadata buffer:
[   94.978270] 000000004b2e7b45: 00 00 00 00 00 00 00 00 3b ee 00 00 00 00 00 00  ........;.......
[   94.980268] 000000006b1db90b: 00 00 00 00 00 81 14 80 00 00 00 00 00 00 00 00  ................
[   94.982251] 00000000433f2407: 22 7b 5c 82 2d 5c 47 4c bb 31 1c 37 fa a9 ce d6  "{\.-\GL.1.7....
[   94.984157] 0000000010dc7dfb: 00 00 00 00 00 81 04 8a 00 0a 18 e8 dd 94 01 00  ................
[   94.986215] 00000000d5a19229: 00 a0 dc f4 fe 98 01 68 f0 d8 07 e0 00 00 00 00  .......h........
[   94.988171] 00000000521df36c: 0c 2d 32 e2 fe 20 01 00 0c 2d 58 65 fe 0c 01 00  .-2.. ...-Xe....
[   94.990162] 000000008477ae06: 0c 2d 5b 66 fe 8c 01 00 0c 2d 71 35 fe 7c 01 00  .-[f.....-q5.|..
[   94.992139] 00000000a4a6bca6: 0c 2d 72 37 fc d4 01 00 0c 2d d8 b8 f0 90 01 00  .-r7.....-......
[   94.994789] XFS (pmem0): xfs_do_force_shutdown(0x8) called from line 1453 of file fs/xfs/xfs_buf.c. Return address = ffffffff815365f3

This is failing this check:

                end = ichdr.freemap[i].base + ichdr.freemap[i].size;
                if (end < ichdr.freemap[i].base)
>>>>>                   return __this_address;
                if (end > mp->m_attr_geo->blksize)
                        return __this_address;

And from the buffer output above, the freemap array is:

	freemap[0].base = 0x00a0
	freemap[0].size = 0xdcf4	end = 0xdd94
	freemap[1].base = 0xfe98
	freemap[1].size = 0x0168	end = 0x10000
	freemap[2].base = 0xf0d8
	freemap[2].size = 0x07e0	end = 0xf8b8

These all look valid - the block size is 0x10000 and so from the
last check in the above verifier fragment we know that the end
of freemap[1] is valid. The problem is that end is declared as:

	uint16_t	end;

And (uint16_t)0x10000 = 0. So we have a verifier bug here, not a
corruption. Fix the verifier to use uint32_t types for the check and
hence avoid the overflow.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=201577
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-06 07:50:50 -08:00
Allison Henderson 068f985a9e xfs: Add attibute remove and helper functions
This patch adds xfs_attr_remove_args. These sub-routines remove
the attributes specified in @args. We will use this later for setting
parent pointers as a deferred attribute operation.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:21:23 +11:00
Allison Henderson 2f3cd80919 xfs: Add attibute set and helper functions
This patch adds xfs_attr_set_args and xfs_bmap_set_attrforkoff.
These sub-routines set the attributes specified in @args.
We will use this later for setting parent pointers as a deferred
attribute operation.

[dgc: remove attr fork init code from xfs_attr_set_args().]
[dgc: xfs_attr_try_sf_addname() NULLs args.trans after commit.]
[dgc: correct sf add error handling.]

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:21:16 +11:00
Allison Henderson 4c74a56b9d xfs: Add helper function xfs_attr_try_sf_addname
This patch adds a subroutine xfs_attr_try_sf_addname
used by xfs_attr_set.  This subrotine will attempt to
add the attribute name specified in args in shortform,
as well and perform error handling previously done in
xfs_attr_set.

This patch helps to pre-simplify xfs_attr_set for reviewing
purposes and reduce indentation.  New function will be added
in the next patch.

[dgc: moved commit to helper function, too.]

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:20:50 +11:00
Allison Henderson e2421f0b5f xfs: Move fs/xfs/xfs_attr.h to fs/xfs/libxfs/xfs_attr.h
This patch moves fs/xfs/xfs_attr.h to fs/xfs/libxfs/xfs_attr.h
since xfs_attr.c is in libxfs.  We will need these later in
xfsprogs.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:20:45 +11:00
Christoph Hellwig daa79baefc xfs: remove suport for filesystems without unwritten extent flag
The option to enable unwritten extents was made default in 2003,
removed from mkfs in 2007, and cannot be disabled in v5.  We also
rely on it for a lot of common functionality, so filesystems without
it will run a completely untested and buggy code path.  Enabling the
support also is a simple bit flip using xfs_db, so legacy file
systems can still be brought forward.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:18:58 +11:00
Dave Chinner e55ec4ddbe xfs: fix error handling in xfs_bmap_extents_to_btree
Commit 01239d77b9 ("xfs: fix a null pointer dereference in
xfs_bmap_extents_to_btree") attempted to fix a null pointer
dreference when a fuzzing corruption of some kind was found.
This fix was flawed, resulting in assert failures like:

XFS: Assertion failed: ifp->if_broot == NULL, file: fs/xfs/libxfs/xfs_bmap.c, line: 715
.....
Call Trace:
  xfs_bmap_extents_to_btree+0x6b9/0x7b0
  __xfs_bunmapi+0xae7/0xf00
  ? xfs_log_reserve+0x1c8/0x290
  xfs_reflink_remap_extent+0x20b/0x620
  xfs_reflink_remap_blocks+0x7e/0x290
  xfs_reflink_remap_range+0x311/0x530
  vfs_dedupe_file_range_one+0xd7/0xe0
  vfs_dedupe_file_range+0x15b/0x1a0
  do_vfs_ioctl+0x267/0x6c0

The problem is that the error handling code now asserts that the
inode fork is not in btree format before the error handling code
undoes the modifications that put the fork back in extent format.
Fix this by moving the assert back to after the xfs_iroot_realloc()
call that returns the fork to extent format, and clean up the jump
labels to be meaningful.

Also, returning ENOSPC when xfs_btree_get_bufl() fails to
instantiate the buffer that was allocated (the actual fix in the
commit mentioned above) is incorrect. This is a fatal error - only
an invalid block address or a filesystem shutdown can result in
failing to get a buffer here.

Hence change this to EFSCORRUPTED so that the higher layer knows
this was a corruption related failure and should not treat it as an
ENOSPC error.  This should result in a shutdown (via cancelling a
dirty transaction) which is necessary as we do not attempt to clean
up the (invalid) block that we have already allocated.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-01 08:11:07 +10:00
Eric Sandeen 339e1a3fcd xfs: validate inode di_forkoff
Verify the inode di_forkoff, lifted from xfs_repair's
process_check_inode_forkoff().

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:50:13 +10:00
Eric Sandeen f369a13cea xfs: don't treat unknown di_flags2 as corruption in scrub
xchk_inode_flags2() currently treats any di_flags2 values that the
running kernel doesn't recognize as corruption, and calls
xchk_ino_set_corrupt() if they are set.  However, it's entirely possible
that these flags were set in some newer kernel and are quite valid,
but ignored in this kernel.

(Validators don't care one bit about unknown di_flags2.)

Call xchk_ino_set_warning instead, because this may or may not actually
indicate a problem.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:49:00 +10:00
Brian Foster d5a2e2893d xfs: remove last of unnecessary xfs_defer_cancel() callers
Now that deferred operations are completely managed via
transactions, it's no longer necessary to cancel the dfops in error
paths that already cancel the associated transaction. There are a
few such calls lingering throughout the codebase.

Remove all remaining unnecessary calls to xfs_defer_cancel(). This
leaves xfs_defer_cancel() calls in two places. The first is the call
in the transaction cancel path itself, which facilitates this patch.
The second is made via the xfs_defer_finish() error path to provide
consistent error semantics with transaction commit. For example,
xfs_trans_commit() expects an xfs_defer_finish() failure to clean up
the dfops structure before it returns.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:41:58 +10:00
Linus Torvalds 781fca5b10 Changes for 4.19:
- Use extent maps to track pagecache page status instead of bufferhead
   state.
 - Refactor pagecache read and write paths to use the new iomap library
   functions, which enable us to drop the old bufferhead code for
   pagesize == blocksize filesystems.
 - Set up parallel per-block-per-page metadata to track subpage
   information that was tracked by buffer heads, which enables us to drop
   the old bufferhead code for pagesize > blocksize filesystems.
 - Tie a deferred ops control structure to a transaction so that we can
   take advantage of an upper-level dfops without having to plumb pointer
   passing through the code.
 - Refactor the deferred ops code to track deferred ops as part of the
   transaction structure (instead of as a separate data structure) so
   that we can simplify the scoping rules around defer_ops.
 - Refactor twisty delwri buffer submission code to avoid deadlocks.
 - Shorten and fix indenting problems in the scrub code.
 - Detect obviously bad summary counts at mount and fix them.
 - Directly associate deferred ops control structure with a transaction
   so that callers no longer have to manage it themselves.
 - Remove a couple of IRIX-era inode macros.
 - Remove the long-deprecated 'barrier' and 'nobarrier' mount options.
 - Clean up the inode fork structure a bit.
 - Check for bad fs summary counter values in the superblock.
 - Reduce COW fork lookups during writeback.
 - Refactor the deferred ops control structures into the transaction
   structure, thereby eliminating the need for transaction users to
   handle the deferred ops as a separate data structure.
 - Add the ability to repair AG headers online.
 - Fix a crash due to insufficient return value checking.
 - Various fixes and cleanups.
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Merge tag 'xfs-4.19-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "This is the second part of the XFS changes for 4.19.

  The biggest changes are the removal of buffer heads frm XFS, a massive
  reworking of the deferred transaction operations handling code, the
  removal of the long defunct barrier/nobarrier mount options, and the
  addition of a few more online repair functions.

  Summary:

   - Use extent maps to track pagecache page status instead of
     bufferhead state.

   - Refactor pagecache read and write paths to use the new iomap
     library functions, which enable us to drop the old bufferhead code
     for pagesize == blocksize filesystems.

   - Set up parallel per-block-per-page metadata to track subpage
     information that was tracked by buffer heads, which enables us to
     drop the old bufferhead code for pagesize > blocksize filesystems.

   - Tie a deferred ops control structure to a transaction so that we
     can take advantage of an upper-level dfops without having to plumb
     pointer passing through the code.

   - Refactor the deferred ops code to track deferred ops as part of the
     transaction structure (instead of as a separate data structure) so
     that we can simplify the scoping rules around defer_ops.

   - Refactor twisty delwri buffer submission code to avoid deadlocks.

   - Shorten and fix indenting problems in the scrub code.

   - Detect obviously bad summary counts at mount and fix them.

   - Directly associate deferred ops control structure with a
     transaction so that callers no longer have to manage it themselves.

   - Remove a couple of IRIX-era inode macros.

   - Remove the long-deprecated 'barrier' and 'nobarrier' mount options.

   - Clean up the inode fork structure a bit.

   - Check for bad fs summary counter values in the superblock.

   - Reduce COW fork lookups during writeback.

   - Refactor the deferred ops control structures into the transaction
     structure, thereby eliminating the need for transaction users to
     handle the deferred ops as a separate data structure.

   - Add the ability to repair AG headers online.

   - Fix a crash due to insufficient return value checking.

   - Various fixes and cleanups"

* tag 'xfs-4.19-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (155 commits)
  xfs: fix a null pointer dereference in xfs_bmap_extents_to_btree
  xfs: remove b_last_holder & associated macros
  iomap: Switch to offset_in_page for clarity
  xfs: Close race between direct IO and xfs_break_layouts()
  xfs: repair the AGI
  xfs: repair the AGFL
  xfs: repair the AGF
  xfs: remove dead error handling code in xfs_dquot_disk_alloc()
  xfs: use WRITE_ONCE to update if_seq
  xfs: fix a comment in xfs_log_reserve
  xfs: only validate summary counts on primary superblock
  xfs: substitute spaces with tabs
  xfs: fold dfops into the transaction
  xfs: always defer agfl block frees
  xfs: pass transaction to xfs_defer_add()
  xfs: replace xfs_defer_ops ->dop_pending with on-stack list
  xfs: cancel dfops on xfs_defer_finish() error
  xfs: clean out superfluous dfops dop params/vars
  xfs: drop dop param from xfs_defer_op_type ->finish_item() callback
  xfs: automatic dfops inode relogging
  ...
2018-08-14 08:56:02 -07:00
Shan Hai 01239d77b9 xfs: fix a null pointer dereference in xfs_bmap_extents_to_btree
Fuzzing tool reports a write to null pointer error in the
xfs_bmap_extents_to_btree, fix it by bailing out on encountering
a null pointer.

Signed-off-by: Shan Hai <shan.hai@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-12 08:37:31 -07:00