Commit Graph

538 Commits

Author SHA1 Message Date
Christoph Hellwig 4dcb886987 xfs: refactor xfs_bmap_add_extent_delay_real
Use xfs_iext_get_extent to find, and xfs_iext_update_extent to update
entries in the in-core extent list.  This isolates the function from
the detailed layout of the extent list, and generally makes the code
a lot more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 1abb9e5532 xfs: refactor xfs_bmap_add_extent_hole_real
Use xfs_iext_update_extent to update entries in the in-core extent list.
This isolates the function from the detailed layout of the extent list,
and generally makes the code a lot more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 3ffc18ecd3 xfs: refactor xfs_bmap_add_extent_hole_delay
Use xfs_iext_get_extent to find, and xfs_iext_update_extent to update
entries in the in-core extent list.  This isolates the function from
the detailed layout of the extent list, and generally makes the code
a lot more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 48fd52b16d xfs: refactor xfs_del_extent_real
Use xfs_iext_update_extent to update entries in the in-core extent list.
This isolates the function from the detailed layout of the extent list,
and generally makes the code a lot more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 491f6f8abf xfs: use the state defines in xfs_bmap_del_extent_real
Use the same defines as the other extent add and delete helpers, which
both improves code readability and trace point output.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 0173c689ff xfs: use correct state defines in xfs_bmap_del_extent_{cow,delay}
Use the _FILLING values to match the usage in the xfs_bmap_add_extent_*
helpers.  No change in behavior, just better naming in the code and
tracepoint output.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig 1b24b633aa xfs: move some more code into xfs_bmap_del_extent_real
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:21 -07:00
Christoph Hellwig e1d7553faf xfs: use xfs_bmap_del_extent_delay for the data fork as well
And remove the delalloc code from xfs_bmap_del_extent, which gets renamed
to xfs_bmap_del_extent_real to fit the naming scheme used by the other
xfs_bmap_{add,del}_extent_* routines.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:20 -07:00
Christoph Hellwig 8280f6ed46 xfs: rename bno to end in __xfs_bunmapi
Rename the bno variable that's used as the end of the range in
__xfs_bunmapi to end, which better describes it.  Additionally change
the start variable which takes the initial value of bno to be the
function parameter itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:20 -07:00
Christoph Hellwig b213d69293 xfs: don't set XFS_BTCUR_BPRV_WASDEL in xfs_bunmapi
The XFS_BTCUR_BPRV_WASDEL flag is supposed to indicate that we are
converting a delayed allocation to a real one, which isn't the case
in xfs_bunmapi.  Setting it could theoretically lead to misaccounting
here, but it's unlikely that we ever hit it in practice.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:20 -07:00
Christoph Hellwig e3f0f7563e xfs: use xfs_iext_get_extent instead of open coding it
This avoids exposure to details of the extent list implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:20 -07:00
Christoph Hellwig 5e422f5e4f xfs: fix incorrect extent state in xfs_bmap_add_extent_unwritten_real
There was one spot in xfs_bmap_add_extent_unwritten_real that didn't use the
passed in new extent state but always converted to normal, leading to wrong
behavior when converting from normal to unwritten.

Only found by code inspection, it seems like this code path to move partial
extent from written to unwritten while merging it with the next extent is
rarely exercised.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26 15:38:20 -07:00
Brian Foster 40214d128e xfs: trim writepage mapping to within eof
The writeback rework in commit fbcc025613 ("xfs: Introduce
writeback context for writepages") introduced a subtle change in
behavior with regard to the block mapping used across the
->writepages() sequence. The previous xfs_cluster_write() code would
only flush pages up to EOF at the time of the writepage, thus
ensuring that any pages due to file-extending writes would be
handled on a separate cycle and with a new, updated block mapping.

The updated code establishes a block mapping in xfs_writepage_map()
that could extend beyond EOF if the file has post-eof preallocation.
Because we now use the generic writeback infrastructure and pass the
cached mapping to each writepage call, there is no implicit EOF
limit in place. If eofblocks trimming occurs during ->writepages(),
any post-eof portion of the cached mapping becomes invalid. The
eofblocks code has no means to serialize against writeback because
there are no pages associated with post-eof blocks. Therefore if an
eofblocks trim occurs and is followed by a file-extending buffered
write, not only has the mapping become invalid, but we could end up
writing a page to disk based on the invalid mapping.

Consider the following sequence of events:

- A buffered write creates a delalloc extent and post-eof
  speculative preallocation.
- Writeback starts and on the first writepage cycle, the delalloc
  extent is converted to real blocks (including the post-eof blocks)
  and the mapping is cached.
- The file is closed and xfs_release() trims post-eof blocks. The
  cached writeback mapping is now invalid.
- Another buffered write appends the file with a delalloc extent.
- The concurrent writeback cycle picks up the just written page
  because the writeback range end is LLONG_MAX. xfs_writepage_map()
  attributes it to the (now invalid) cached mapping and writes the
  data to an incorrect location on disk (and where the file offset is
  still backed by a delalloc extent).

This problem is reproduced by xfstests test generic/464, which
triggers racing writes, appends, open/closes and writeback requests.

To address this problem, trim the mapping used during writeback to
within EOF when the mapping is validated. This ensures the mapping
is revalidated for any pages encountered beyond EOF as of the time
the current mapping was cached or last validated.

Reported-by: Eryu Guan <eguan@redhat.com>
Diagnosed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-16 12:26:50 -07:00
Eric Sandeen 93e8befc17 xfs: handle error if xfs_btree_get_bufs fails
Jason reported that a corrupted filesystem failed to replay
the log with a metadata block out of bounds warning:

XFS (dm-2): _xfs_buf_find: Block out of range: block 0x80270fff8, EOFS 0x9c40000

_xfs_buf_find() and xfs_btree_get_bufs() return NULL if
that happens, and then when xfs_alloc_fix_freelist() calls
xfs_trans_binval() on that NULL bp, we oops with:

BUG: unable to handle kernel NULL pointer dereference at 00000000000000f8

We don't handle _xfs_buf_find errors very well, every
caller higher up the stack gets to guess at why it failed.
But we should at least handle it somehow, so return
EFSCORRUPTED here.

Reported-by: Jason L Tibbitts III <tibbs@math.uh.edu>
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>
2017-10-11 10:21:07 -07:00
Thomas Meyer 749f24f33e xfs: Fix bool initialization/comparison
Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-11 10:21:06 -07:00
Dave Chinner 20413e37d7 xfs: Don't log uninitialised fields in inode structures
Prevent kmemcheck from throwing warnings about reading uninitialised
memory when formatting inodes into the incore log buffer. There are
several issues here - we don't always log all the fields in the
inode log format item, and we never log the inode the
di_next_unlinked field.

In the case of the inode log format item, this is exacerbated
by the old xfs_inode_log_format structure padding issue. Hence make
the padded, 64 bit aligned version of the structure the one we always
use for formatting the log and get rid of the 64 bit variant. This
means we'll always log the 64-bit version and so recovery only needs
to convert from the unpadded 32 bit version from older 32 bit
kernels.

Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-11 10:21:06 -07:00
Darrick J. Wong 5e5c943c1f xfs: revert "xfs: factor rmap btree size into the indlen calculations"
In commit fd26a88093 we added a worst case estimate for rmapbt blocks
needed to satisfy the block mapping request.  Since then, we added the
ability to reserve enough space in each AG such that we should never run
out of blocks to grow the rmapbt, which makes this calculation
unnecessary.  Revert the commit because it makes the extra delalloc
indlen accounting unnecessary and incorrect.

Reported-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-26 10:55:20 -07:00
Darrick J. Wong 9789dd9e1d xfs: perag initialization should only touch m_ag_max_usable for AG 0
We call __xfs_ag_resv_init to make a per-AG reservation for each AG.
This makes the reservation per-AG, not per-filesystem.  Therefore, it
is incorrect to adjust m_ag_max_usable for each AG.  Adjust it only
when we're reserving AG 0's blocks so that we only do it once per fs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-09-26 10:55:19 -07:00
Darrick J. Wong 7bf7a193a9 xfs: fix compiler warnings
Fix up all the compiler warnings that have crept in.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-09-02 08:22:19 -07:00
Darrick J. Wong 4cc1ee5e65 xfs: simplify the rmap code in xfs_bmse_merge
In Christoph's patch to refactor xfs_bmse_merge, the updated rmap code
does more work than it needs to (because map-extent auto-merges
records).  Remove the unnecessary unmap and save ourselves a deferred
op.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-09-01 13:08:26 -07:00
Christoph Hellwig 4c35445b59 xfs: use xfs_iext_*_extent helpers in xfs_bmap_split_extent_at
This abstracts the function away from details of the low-level extent
list implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 13:08:25 -07:00
Christoph Hellwig 4da6b514ea xfs: use xfs_iext_*_extent helpers in xfs_bmap_shift_extents
This abstracts the function away from details of the low-level extent
list implementation.

Note that it seems like the previous implementation of rmap for
the merge case was completely broken, but it no seems appear to
trigger that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 13:08:25 -07:00
Christoph Hellwig 05b7c8ab2b xfs: move some code around inside xfs_bmap_shift_extents
For the first right move we need to look up next_fsb.  That means
our last fsb that contains next_fsb must also be the current extent,
so take advantage of that by moving the code around a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 13:08:25 -07:00
Christoph Hellwig f2285c148c xfs: use xfs_iext_get_extent in xfs_bmap_first_unused
Use the bmap abstraction instead of open-coding bmbt details here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig 50bb44c286 xfs: switch xfs_bmap_local_to_extents to use xfs_iext_insert
Use the helper instead of open coding it, to provide a better abstraction
for the scalable extent list work.  This also gets an additional assert
and trace point for free.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig 67e4e69cb2 xfs: add a xfs_iext_update_extent helper
This helper is used to update an extent record based on the extent index,
and can be used to provide a level of abstractions between callers that
want to modify in-core extent records and the details of the extent list
implementation.

Also switch all users of the xfs_bmbt_set_all(xfs_iext_get_ext(...))
pattern to this new helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Brian Foster 2dd3d709fc xfs: relog dirty buffers during swapext bmbt owner change
The owner change bmbt scan that occurs during extent swap operations
does not handle ordered buffer failures. Buffers that cannot be
marked ordered must be physically logged so previously dirty ranges
of the buffer can be relogged in the transaction.

Since the bmbt scan may need to process and potentially log a large
number of blocks, we can't expect to complete this operation in a
single transaction. Update extent swap to use a permanent
transaction with enough log reservation to physically log a buffer.
Update the bmbt scan to physically log any buffers that cannot be
ordered and to terminate the scan with -EAGAIN. On -EAGAIN, the
caller rolls the transaction and restarts the scan. Finally, update
the bmbt scan helper function to skip bmbt blocks that already match
the expected owner so they are not reprocessed after scan restarts.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[darrick: fix the xfs_trans_roll call]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Brian Foster 99c794c639 xfs: skip bmbt block ino validation during owner change
Extent swap uses xfs_btree_visit_blocks() to fix up bmbt block
owners on v5 (!rmapbt) filesystems. The bmbt scan uses
xfs_btree_lookup_get_block() to read bmbt blocks which verifies the
current owner of the block against the parent inode of the bmbt.
This works during extent swap because the bmbt owners are updated to
the opposite inode number before the inode extent forks are swapped.

The modified bmbt blocks are marked as ordered buffers which allows
everything to commit in a single transaction. If the transaction
commits to the log and the system crashes such that recovery of the
extent swap is required, log recovery restarts the bmbt scan to fix
up any bmbt blocks that may have not been written back before the
crash. The log recovery bmbt scan occurs after the inode forks have
been swapped, however. This causes the bmbt block owner verification
to fail, leads to log recovery failure and requires xfs_repair to
zap the log to recover.

Define a new invalid inode owner flag to inform the btree block
lookup mechanism that the current inode may be invalid with respect
to the current owner of the bmbt block. Set this flag on the cursor
used for change owner scans to allow this operation to work at
runtime and during log recovery.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Fixes: bb3be7e7c ("xfs: check for bogus values in btree block headers")
Cc: stable@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Brian Foster 8dc518dfa7 xfs: don't log dirty ranges for ordered buffers
Ordered buffers are attached to transactions and pushed through the
logging infrastructure just like normal buffers with the exception
that they are not actually written to the log. Therefore, we don't
need to log dirty ranges of ordered buffers. xfs_trans_log_buf() is
called on ordered buffers to set up all of the dirty state on the
transaction, buffer and log item and prepare the buffer for I/O.

Now that xfs_trans_dirty_buf() is available, call it from
xfs_trans_ordered_buf() so the latter is now mutually exclusive with
xfs_trans_log_buf(). This reflects the implementation of ordered
buffers and helps eliminate confusion over the need to log ranges of
ordered buffers just to set up internal log state.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig 8ad7c629b1 xfs: remove the ip argument to xfs_defer_finish
And instead require callers to explicitly join the inode using
xfs_defer_ijoin.  Also consolidate the defer error handling in
a few places using a goto label.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig 882d8785fb xfs: rename xfs_defer_join to xfs_defer_ijoin
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig 411350df14 xfs: refactor xfs_trans_roll
Split xfs_trans_roll into a low-level helper that just rolls the
actual transaction and a new higher level xfs_trans_roll_inode
that takes care of logging and rejoining the inode.  This gets
rid of the NULL inode case, and allows to simplify the special
cases in the deferred operation code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Carlos Maiolino 2d32311cf1 xfs: stop searching for free slots in an inode chunk when there are none
In a filesystem without finobt, the Space manager selects an AG to alloc a new
inode, where xfs_dialloc_ag_inobt() will search the AG for the free slot chunk.

When the new inode is in the same AG as its parent, the btree will be searched
starting on the parent's record, and then retried from the top if no slot is
available beyond the parent's record.

To exit this loop though, xfs_dialloc_ag_inobt() relies on the fact that the
btree must have a free slot available, once its callers relied on the
agi->freecount when deciding how/where to allocate this new inode.

In the case when the agi->freecount is corrupted, showing available inodes in an
AG, when in fact there is none, this becomes an infinite loop.

Add a way to stop the loop when a free slot is not found in the btree, making
the function to fall into the whole AG scan which will then, be able to detect
the corruption and shut the filesystem down.

As pointed by Brian, this might impact performance, giving the fact we
don't reset the search distance anymore when we reach the end of the
tree, giving it fewer tries before falling back to the whole AG search, but
it will only affect searches that start within 10 records to the end of the tree.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-22 09:22:24 -07:00
Omar Sandoval c44245b3d5 xfs: fix inobt inode allocation search optimization
When we try to allocate a free inode by searching the inobt, we try to
find the inode nearest the parent inode by searching chunks both left
and right of the chunk containing the parent. As an optimization, we
cache the leftmost and rightmost records that we previously searched; if
we do another allocation with the same parent inode, we'll pick up the
search where it last left off.

There's a bug in the case where we found a free inode to the left of the
parent's chunk: we need to update the cached left and right records, but
because we already reassigned the right record to point to the left, we
end up assigning the left record to both the cached left and right
records.

This isn't a correctness problem strictly, but it can result in the next
allocation rechecking chunks unnecessarily or allocating inodes further
away from the parent than it needs to. Fix it by swapping the record
pointer after we update the cached left and right records.

Fixes: bd16956599 ("xfs: speed up free inode search")
Signed-off-by: Omar Sandoval <osandov@fb.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>
2017-08-11 16:56:33 -07:00
Christoph Hellwig 5b094d6dac xfs: fix multi-AG deadlock in xfs_bunmapi
Just like in the allocator we must avoid touching multiple AGs out of
order when freeing blocks, as freeing still locks the AGF and can cause
the same AB-BA deadlocks as in the allocation path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-26 08:20:03 -07:00
Darrick J. Wong 6215894e11 xfs: check that dir block entries don't off the end of the buffer
When we're checking the entries in a directory buffer, make sure that
the entry length doesn't push us off the end of the buffer.  Found via
xfs/388 writing ones to the length fields.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-25 08:36:35 -07:00
Darrick J. Wong 10479e2dea xfs: check _alloc_read_agf buffer pointer before using
In some circumstances, _alloc_read_agf can return an error code of zero
but also a null AGF buffer pointer.  Check for this and jump out.

Fixes-coverity-id: 1415250
Fixes-coverity-id: 1415320
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-20 14:42:33 -07:00
Darrick J. Wong 4c1a67bd36 xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write
We must initialize the firstfsb parameter to _bmapi_write so that it
doesn't incorrectly treat stack garbage as a restriction on which AGs
it can search for free space.

Fixes-coverity-id: 1402025
Fixes-coverity-id: 1415167
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-20 14:42:33 -07:00
Darrick J. Wong 1e86eabe73 xfs: check _btree_check_block value
Check the _btree_check_block return value for the firstrec and lastrec
functions, since we have the ability to signal that the repositioning
did not succeed.

Fixes-coverity-id: 114067
Fixes-coverity-id: 114068
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-20 14:42:32 -07:00
Christoph Hellwig 0891f9971a Revert "xfs: grab dquots without taking the ilock"
This reverts commit 50e0bdbe9f.

The new XFS_QMOPT_NOLOCK isn't used at all, and conditional locking based
on a flag is always the wrong thing to do - we should be having helpers
that can be called without the lock instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-13 14:55:05 -07:00
Christoph Hellwig cf69f8248c xfs: fixup xfs_attr_get_ilocked
The comment mentioned the wrong lock.  Also add an ASSERT to assert
this locking precondition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-13 14:55:05 -07:00
Darrick J. Wong cd87d86792 xfs: don't crash on unexpected holes in dir/attr btrees
In quite a few places we call xfs_da_read_buf with a mappedbno that we
don't control, then assume that the function passes back either an error
code or a buffer pointer.  Unfortunately, if mappedbno == -2 and bno
maps to a hole, we get a return code of zero and a NULL buffer, which
means that we crash if we actually try to use that buffer pointer.  This
happens immediately when we set the buffer type for transaction context.

Therefore, check that we have no error code and a non-NULL bp before
trying to use bp.  This patch is a follow-up to an incomplete fix in
96a3aefb8f ("xfs: don't crash if reading a directory results in an
unexpected hole").

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-07 18:55:17 -07:00
Darrick J. Wong 6eb0b8df9f xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN
XFS has a maximum symlink target length of 1024 bytes; this is a
holdover from the Irix days.  Unfortunately, the constant establishing
this is 'MAXPATHLEN' and is /not/ the same as the Linux MAXPATHLEN,
which is 4096.

The kernel enforces its 1024 byte MAXPATHLEN on symlink targets, but
xfsprogs picks up the (Linux) system 4096 byte MAXPATHLEN, which means
that xfs_repair doesn't complain about oversized symlinks.

Since this is an on-disk format constraint, put the define in the XFS
namespace and move everything over to use the new name.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-07 08:37:26 -07:00
Darrick J. Wong 50e0bdbe9f xfs: grab dquots without taking the ilock
Add a new dqget flag that grabs the dquot without taking the ilock.
This will be used by the scrubber (which will have already grabbed
the ilock) to perform basic sanity checking of the quota data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-27 18:23:22 -07:00
Darrick J. Wong 9e24cfd044 xfs: remove unneeded parameter from XFS_TEST_ERROR
Since we moved the injected error frequency controls to the mountpoint,
we can get rid of the last argument to XFS_TEST_ERROR.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-06-27 18:23:20 -07:00
Darrick J. Wong ad017f6537 xfs: pass along transaction context when reading xattr block buffers
Teach the extended attribute reading functions to pass along a
transaction context if one was supplied.  The extended attribute scrub
code will use transactions to lock buffers and avoid deadlocking with
itself in the case of loops; since it will already have the inode
locked, also create xattr get/list helpers that don't take locks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-20 10:45:22 -07:00
Darrick J. Wong acb9553cab xfs: pass along transaction context when reading directory block buffers
Teach the directory reading functions to pass along a transaction context
if one was supplied.  The directory scrub code will use transactions to
lock buffers and avoid deadlocking with itself in the case of loops.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-20 10:45:22 -07:00
Darrick J. Wong 8e8877e6ed xfs: return the hash value of a leaf1 directory block
Modify the existing dir leafn lasthash function to enable us to
calculate the highest hash value of a leaf1 block.  This will be used by
the directory scrubbing code to check the sanity of hashes in leaf1
directory blocks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-20 10:45:21 -07:00
Darrick J. Wong e936945ee4 xfs: export _inobt_btrec_to_irec and _ialloc_cluster_alignment for scrub
Create a function to extract an in-core inobt record from a generic
btree_rec union so that scrub will be able to check inobt records
and check inode block alignment.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19 14:11:34 -07:00
Darrick J. Wong 118bb47e28 xfs: plumb in needed functions for range querying of various btrees
Plumb in the pieces (init_high_key, diff_two_keys) necessary to call
query_range on the inode space and block mapping btrees and to extract
raw btree records.  This will eventually be used by the inobt and bmbt
scrubbers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19 14:11:34 -07:00
Darrick J. Wong 2678809799 xfs: export various function for the online scrubber
Export various internal functions so that the online scrubber can use
them to check the state of metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19 14:11:34 -07:00
Darrick J. Wong 38dee376d6 xfs: always compile the btree inorder check functions
The btree record and key inorder check functions will be used by the
btree scrubber code, so make sure they're always built.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19 14:11:33 -07:00
Darrick J. Wong c8ce540db5 xfs: remove double-underscore integer types
This is a purely mechanical patch that removes the private
__{u,}int{8,16,32,64}_t typedefs in favor of using the system
{u,}int{8,16,32,64}_t typedefs.  This is the sed script used to perform
the transformation and fix the resulting whitespace and indentation
errors:

s/typedef\t__uint8_t/typedef __uint8_t\t/g
s/typedef\t__uint/typedef __uint/g
s/typedef\t__int\([0-9]*\)_t/typedef int\1_t\t/g
s/__uint8_t\t/__uint8_t\t\t/g
s/__uint/uint/g
s/__int\([0-9]*\)_t\t/__int\1_t\t\t/g
s/__int/int/g
/^typedef.*int[0-9]*_t;$/d

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-06-19 14:11:33 -07:00
Darrick J. Wong 5a4c73342a xfs: optimize _btree_query_all
Don't bother wandering our way through the leaf nodes when the caller
issues a query_all; just zoom down the left side of the tree and walk
rightwards along level zero.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19 14:11:33 -07:00
Christoph Hellwig 3398a4005f xfs: remove XFS_HSIZE
XFS_HSIZE is an extremly confusing way to calculate the size of handle_t.
Given that handle_t always only had two sizes, and one of them isn't
even covered by XFS_HSIZE to start with just remove the macro and use
a constant sizeof expression.

Note that XFS_HSIZE isn't used in xfsprogs, xfsdump or xfstests either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-19 08:59:10 -07:00
Darrick J. Wong e1a4e37cc7 xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent
In a pathological scenario where we are trying to bunmapi a single
extent in which every other block is shared, it's possible that trying
to unmap the entire large extent in a single transaction can generate so
many EFIs that we overflow the transaction reservation.

Therefore, use a heuristic to guess at the number of blocks we can
safely unmap from a reflink file's data fork in an single transaction.
This should prevent problems such as the log head slamming into the tail
and ASSERTs that trigger because we've exceeded the transaction
reservation.

Note that since bunmapi can fail to unmap the entire range, we must also
teach the deferred unmap code to roll into a new transaction whenever we
get low on reservation.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[hch: random edits, all bugs are my fault]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-19 08:59:10 -07:00
Eric Sandeen a4d768e702 xfs: fix unaligned access in xfs_btree_visit_blocks
This structure copy was throwing unaligned access warnings on sparc64:

Kernel unaligned access at TPC[1043c088] xfs_btree_visit_blocks+0x88/0xe0 [xfs]

xfs_btree_copy_ptrs does a memcpy, which avoids it.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-25 09:42:25 -07:00
Darrick J. Wong 3ecb3ac7b9 xfs: avoid mount-time deadlock in CoW extent recovery
If a malicious user corrupts the refcount btree to cause a cycle between
different levels of the tree, the next mount attempt will deadlock in
the CoW recovery routine while grabbing buffer locks.  We can use the
ability to re-grab a buffer that was previous locked to a transaction to
avoid deadlocks, so do that here.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-05-19 08:12:49 -07:00
Darrick J. Wong 6e747506dd xfs: fix warnings about unused stack variables
Reduce stack usage and get rid of compiler warnings by eliminating
unused variables.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-05-16 09:24:36 -07:00
Brian Foster 0daaecacb8 xfs: fix indlen accounting error on partial delalloc conversion
The delalloc -> real block conversion path uses an incorrect
calculation in the case where the middle part of a delalloc extent
is being converted. This is documented as a rare situation because
XFS generally attempts to maximize contiguity by converting as much
of a delalloc extent as possible.

If this situation does occur, the indlen reservation for the two new
delalloc extents left behind by the conversion of the middle range
is calculated and compared with the original reservation. If more
blocks are required, the delta is allocated from the global block
pool. This delta value can be characterized as the difference
between the new total requirement (temp + temp2) and the currently
available reservation minus those blocks that have already been
allocated (startblockval(PREV.br_startblock) - allocated).

The problem is that the current code does not account for previously
allocated blocks correctly. It subtracts the current allocation
count from the (new - old) delta rather than the old indlen
reservation. This means that more indlen blocks than have been
allocated end up stashed in the remaining extents and free space
accounting is broken as a result.

Fix up the calculation to subtract the allocated block count from
the original extent indlen and thus correctly allocate the
reservation delta based on the difference between the new total
requirement and the unused blocks from the original reservation.
Also remove a bogus assert that contradicts the fact that the new
indlen reservation can be larger than the original indlen
reservation.

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>
2017-05-16 09:24:35 -07:00
Linus Torvalds d484467c86 Changes for 4.12:
- various code cleanups
 - introduce GETFSMAP ioctl
 - various refactoring
 - avoid dio reads past eof
 - fix memory corruption and other errors with fragmented directory blocks
 - fix accidental userspace memory corruptions
 - publish fs uuid in superblock
 - make fstrim terminatable
 - fix race between quotaoff and in-core inode creation
 - Avoid use-after-free when finishing up w/ buffer heads
 - Reserve enough space to handle bmap tree resizing during cow remap
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Merge tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "Here are the XFS changes for 4.12. The big new feature for this
  release is the new space mapping ioctl that we've been discussing
  since LSF2016, but other than that most of the patches are larger bug
  fixes, memory corruption prevention, and other cleanups.

  Summary:
   - various code cleanups
   - introduce GETFSMAP ioctl
   - various refactoring
   - avoid dio reads past eof
   - fix memory corruption and other errors with fragmented directory blocks
   - fix accidental userspace memory corruptions
   - publish fs uuid in superblock
   - make fstrim terminatable
   - fix race between quotaoff and in-core inode creation
   - avoid use-after-free when finishing up w/ buffer heads
   - reserve enough space to handle bmap tree resizing during cow remap"

* tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (53 commits)
  xfs: fix use-after-free in xfs_finish_page_writeback
  xfs: reserve enough blocks to handle btree splits when remapping
  xfs: wait on new inodes during quotaoff dquot release
  xfs: update ag iterator to support wait on new inodes
  xfs: support ability to wait on new inodes
  xfs: publish UUID in struct super_block
  xfs: Allow user to kill fstrim process
  xfs: better log intent item refcount checking
  xfs: fix up quotacheck buffer list error handling
  xfs: remove xfs_trans_ail_delete_bulk
  xfs: don't use bool values in trace buffers
  xfs: fix getfsmap userspace memory corruption while setting OF_LAST
  xfs: fix __user annotations for xfs_ioc_getfsmap
  xfs: corruption needs to respect endianess too!
  xfs: use NULL instead of 0 to initialize a pointer in xfs_ioc_getfsmap
  xfs: use NULL instead of 0 to initialize a pointer in xfs_getfsmap
  xfs: simplify validation of the unwritten extent bit
  xfs: remove unused values from xfs_exntst_t
  xfs: remove the unused XFS_MAXLINK_1 define
  xfs: more do_div cleanups
  ...
2017-05-06 11:46:16 -07:00
Michal Hocko 9070733b4e xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS
xfs has defined PF_FSTRANS to declare a scope GFP_NOFS semantic quite
some time ago.  We would like to make this concept more generic and use
it for other filesystems as well.  Let's start by giving the flag a more
generic name PF_MEMALLOC_NOFS which is in line with an exiting
PF_MEMALLOC_NOIO already used for the same purpose for GFP_NOIO
contexts.  Replace all PF_FSTRANS usage from the xfs code in the first
step before we introduce a full API for it as xfs uses the flag directly
anyway.

This patch doesn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170306131408.9828-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03 15:52:09 -07:00
Darrick J. Wong fe0be23e68 xfs: reserve enough blocks to handle btree splits when remapping
In xfs_reflink_end_cow, we erroneously reserve only enough blocks to
handle adding 1 extent.  This is problematic if we fragment free space,
have to do CoW, and then have to perform multiple bmap btree expansions.
Furthermore, the BUI recovery routine doesn't reserve /any/ blocks to
handle btree splits, so log recovery fails after our first error causes
the filesystem to go down.

Therefore, refactor the transaction block reservation macros until we
have a macro that works for our deferred (re)mapping activities, and fix
both problems by using that macro.

With 1k blocks we can hit this fairly often in g/187 if the scratch fs
is big enough.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-05-03 13:21:40 -07:00
Christoph Hellwig 0c1d9e4a61 xfs: simplify validation of the unwritten extent bit
XFS only supports the unwritten extent bit in the data fork, and only if
the file system has a version 5 superblock or the unwritten extent
feature bit.

We currently have two routines that validate the invariant:
xfs_check_nostate_extents which return -EFSCORRUPTED when it's not met,
and xfs_validate_extent that triggers and assert in debug build.

Both of them iterate over all extents of an inode fork when called,
which isn't very efficient.

This patch instead adds a new helper that verifies the invariant one
extent at a time, and calls it from the places where we iterate over
all extents to converted them from or two the in-memory format.  The
callers then return -EFSCORRUPTED when reading invalid extents from
disk, or trigger an assert when writing them to disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:41 -07:00
Christoph Hellwig 37f7f9bbf3 xfs: remove unused values from xfs_exntst_t
We only ever use the normal and unwritten states.  And the actual
ondisk format (this enum isn't despite being in xfs_format.h) only
has space for the unwritten bit anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:41 -07:00
Christoph Hellwig 895e9bfc9e xfs: remove the unused XFS_MAXLINK_1 define
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:41 -07:00
Eric Sandeen 4f1adf3373 xfs: more do_div cleanups
On some architectures do_div does the pointer compare
trick to make sure that we've sent it an unsigned 64-bit
number.  (Why unsigned?  I don't know.)

Fix up the few places that squawk about this; in
xfs_bmap_wants_extents() we just used a bare int64_t so change
that to unsigned.

In xfs_adjust_extent_unmap_boundaries() all we wanted was the
mod, and we have an xfs-specific function to handle that w/o
side effects, which includes proper casting for do_div.

In xfs_daddr_to_ag[b]no, we were using the wrong type anyway;
XFS_BB_TO_FSBT returns a block in the filesystem, so use
xfs_rfsblock_t not xfs_daddr_t, and gain the unsignedness
from that type as a bonus.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:41 -07:00
Christoph Hellwig 7590632a33 xfs: remove bmap block allocation retries
Now that reflink operations don't set the firstblock value we don't
need the workarounds for non-NULL firstblock values without a prior
allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:40 -07:00
Christoph Hellwig bf8eadbacb xfs: remove xfs_bmap_remap_alloc
The main thing that xfs_bmap_remap_alloc does is fixing the AGFL, similar
to what we do in the space allocator.  But the reflink code doesn't touch
the allocation btree unlike the normal space allocator, so we couldn't
care less about the state of the AGFL.

So remove xfs_bmap_remap_alloc and just handle the di_nblocks update in
the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:40 -07:00
Christoph Hellwig 6ebd5a4413 xfs: introduce xfs_bmapi_remap
Add a new helper to be used for reflink extent list additions instead of
funneling them through xfs_bmapi_write and overloading the firstblock
member in struct xfs_bmalloca and struct xfs_alloc_args.

With some small changes to xfs_bmap_remap_alloc this also means we do
not need a xfs_bmalloca structure for this case at all.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:39 -07:00
Christoph Hellwig 6d04558f9f xfs: pass individual arguments to xfs_bmap_add_extent_hole_real
For the reflink case we'd much rather pass the required arguments than
faking up a struct xfs_bmalloca.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:39 -07:00
Christoph Hellwig 39e07daa46 xfs: remove attr fork handling in xfs_bmap_finish_one
We never do COW operations for the attr fork, so don't pretend we handle
them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:39 -07:00
Christoph Hellwig 52813fb13f xfs: fix integer truncation in xfs_bmap_remap_alloc
bno should be a xfs_fsblock_t, which is 64-bit wides instead of a
xfs_aglock_t, which truncates the value to 32 bits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25 09:40:39 -07:00
Eric Sandeen d956f813b6 xfs: simplify xfs_calc_dquots_per_chunk
ndquots is a 32-bit value, and we don't care
about the remainder; there is no reason to use do_div
here, it seems to be the result of a decade+ historical
accident.

Worse, the do_div implementation in userspace breaks
when fed a 32-bit dividend, so we commented it out there
in any case.

Change to simple division, and then we can change
userspace to match, and mandate a 64-bit dividend in
the do_div() in userspace as well.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
2017-04-12 08:42:51 -07:00
Darrick J. Wong e89c041338 xfs: implement the GETFSMAP ioctl
Introduce a new ioctl that uses the reverse mapping btree to return
information about the physical layout of the filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-04-03 15:18:17 -07:00
Darrick J. Wong fb3c3de2f6 xfs: add a couple of queries to iterate free extents in the rtbitmap
Add _query_range and _query_all functions to the realtime bitmap
allocator.  These two functions are similar in usage to the btree
functions with the same name and will be used for getfsmap and scrub.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-04-03 15:18:17 -07:00
Darrick J. Wong e9a2599a24 xfs: create a function to query all records in a btree
Create a helper function that will query all records in a btree.
This will be used by the online repair functions to examine every
record in a btree to rebuild a second btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-04-03 15:18:17 -07:00
Darrick J. Wong 2d520bfaa2 xfs: provide a query_range function for freespace btrees
Implement a query_range function for the bnobt and cntbt.  This will
be used for getfsmap fallback if there is no rmapbt and by the online
scrub and repair code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-04-03 15:18:17 -07:00
Darrick J. Wong 08438b1e38 xfs: plumb in needed functions for range querying of the freespace btrees
Plumb in the pieces (init_high_key, diff_two_keys) necessary to call
query_range on the free space btrees.  Remove the debugging asserts
so that we can make queries starting from block 0.

While we're at it, merge the redundant "if (btnum ==" hunks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-04-03 15:18:17 -07:00
Eric Sandeen bc593eebfd xfs: fix up inode validation failure message
"xfs_iread: validation failed for inode 96 failed"

One "failed" seems like enough.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-03 15:18:16 -07:00
Christoph Hellwig 63fbb4c18d xfs: remove the ISUNWRITTEN macro
Opencoding the trivial checks makes it much easier to read (and grep..).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-03 15:18:16 -07:00
Christoph Hellwig 9c4f29d391 xfs: factor out a xfs_bmap_is_real_extent helper
This checks for all the non-normal extent types, including handling both
encodings of delayed allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-03 15:18:16 -07:00
Darrick J. Wong 78420281a9 xfs: rework the inline directory verifiers
The inline directory verifiers should be called on the inode fork data,
which means after iformat_local on the read side, and prior to
ifork_flush on the write side.  This makes the fork verifier more
consistent with the way buffer verifiers work -- i.e. they will operate
on the memory buffer that the code will be reading and writing directly.

Furthermore, revise the verifier function to return -EFSCORRUPTED so
that we don't flood the logs with corruption messages and assert
notices.  This has been a particular problem with xfs/348, which
triggers the XFS_WANT_CORRUPTED_RETURN assertions, which halts the
kernel when CONFIG_XFS_DEBUG=y.  Disk corruption isn't supposed to do
that, at least not in a verifier.

Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-03 12:22:20 -07:00
Darrick J. Wong 005c5db8fd xfs: rework the inline directory verifiers
The inline directory verifiers should be called on the inode fork data,
which means after iformat_local on the read side, and prior to
ifork_flush on the write side.  This makes the fork verifier more
consistent with the way buffer verifiers work -- i.e. they will operate
on the memory buffer that the code will be reading and writing directly.

Furthermore, revise the verifier function to return -EFSCORRUPTED so
that we don't flood the logs with corruption messages and assert
notices.  This has been a particular problem with xfs/348, which
triggers the XFS_WANT_CORRUPTED_RETURN assertions, which halts the
kernel when CONFIG_XFS_DEBUG=y.  Disk corruption isn't supposed to do
that, at least not in a verifier.

Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: get the inode d_ops the proper way
v3: describe the bug that this patch fixes; no code changes
2017-03-28 14:51:10 -07:00
Darrick J. Wong 630a04e79d xfs: verify inline directory data forks
When we're reading or writing the data fork of an inline directory,
check the contents to make sure we're not overflowing buffers or eating
garbage data.  xfs/348 corrupts an inline symlink into an inline
directory, triggering a buffer overflow bug.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
v2: add more checks consistent with _dir2_sf_check and make the verifier
usable from anywhere.
2017-03-15 00:24:25 -07:00
Christoph Hellwig 2fcc319d24 xfs: try any AG when allocating the first btree block when reflinking
When a reflink operation causes the bmap code to allocate a btree block
we're currently doing single-AG allocations due to having ->firstblock
set and then try any higher AG due a little reflink quirk we've put in
when adding the reflink code.  But given that we do not have a minleft
reservation of any kind in this AG we can still not have any space in
the same or higher AG even if the file system has enough free space.
To fix this use a XFS_ALLOCTYPE_FIRST_AG allocation in this fall back
path instead.

[And yes, we need to redo this properly instead of piling hacks over
 hacks.  I'm working on that, but it's not going to be a small series.
 In the meantime this fixes the customer reported issue]

Also add a warning for failing allocations to make it easier to debug.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-03-08 10:38:53 -08:00
Brian Foster f65e6fad29 xfs: use iomap new flag for newly allocated delalloc blocks
Commit fa7f138 ("xfs: clear delalloc and cache on buffered write
failure") fixed one regression in the iomap error handling code and
exposed another. The fundamental problem is that if a buffered write
is a rewrite of preexisting delalloc blocks and the write fails, the
failure handling code can punch out preexisting blocks with valid
file data.

This was reproduced directly by sub-block writes in the LTP
kernel/syscalls/write/write03 test. A first 100 byte write allocates
a single block in a file. A subsequent 100 byte write fails and
punches out the block, including the data successfully written by
the previous write.

To address this problem, update the ->iomap_begin() handler to
distinguish newly allocated delalloc blocks from preexisting
delalloc blocks via the IOMAP_F_NEW flag. Use this flag in the
->iomap_end() handler to decide when a failed or short write should
punch out delalloc blocks.

This introduces the subtle requirement that ->iomap_begin() should
never combine newly allocated delalloc blocks with existing blocks
in the resulting iomap descriptor. This can occur when a new
delalloc reservation merges with a neighboring extent that is part
of the current write, for example. Therefore, drop the
post-allocation extent lookup from xfs_bmapi_reserve_delalloc() and
just return the record inserted into the fork. This ensures only new
blocks are returned and thus that preexisting delalloc blocks are
always handled as "found" blocks and not punched out on a failed
rewrite.

Reported-by: Xiong Zhou <xzhou@redhat.com>
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>
2017-03-08 09:58:08 -08:00
Christoph Hellwig 8d242e932f xfs: remove XFS_ALLOCTYPE_ANY_AG and XFS_ALLOCTYPE_START_AG
XFS_ALLOCTYPE_ANY_AG  was only used for the RT allocator and is unused
now, and XFS_ALLOCTYPE_START_AG has been unused for a while.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-17 20:32:10 -08:00
Christoph Hellwig 410d17f67e xfs: tune down agno asserts in the bmap code
In various places we currently assert that xfs_bmap_btalloc allocates
from the same as the firstblock value passed in, unless it's either
NULLAGNO or the dop_low flag is set.  But the reflink code does not
fully follow this convention as it passes in firstblock purely as
a hint for the allocator without actually having previous allocations
in the transaction, and without having a minleft check on the current
AG, leading to the assert firing on a very full and heavily used
file system.  As even the reflink code only allocates from equal or
higher AGs for now we can simply the check to always allow for equal
or higher AGs.

Note that we need to eventually split the two meanings of the firstblock
value.  At that point we can also allow the reflink code to allocate
from any AG instead of limiting it in any way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-16 17:20:39 -08:00
Chandan Rajendra 8ee9fdbebc xfs: Use xfs_icluster_size_fsb() to calculate inode chunk alignment
On a ppc64 system, executing generic/256 test with 32k block size gives the following call trace,

XFS: Assertion failed: args->maxlen > 0, file: /root/repos/linux/fs/xfs/libxfs/xfs_alloc.c, line: 2026

kernel BUG at /root/repos/linux/fs/xfs/xfs_message.c:113!
Oops: Exception in kernel mode, sig: 5 [#1]
SMP NR_CPUS=2048
DEBUG_PAGEALLOC
NUMA
pSeries
Modules linked in:
CPU: 2 PID: 19361 Comm: mkdir Not tainted 4.10.0-rc5 #58
task: c000000102606d80 task.stack: c0000001026b8000
NIP: c0000000004ef798 LR: c0000000004ef798 CTR: c00000000082b290
REGS: c0000001026bb090 TRAP: 0700   Not tainted  (4.10.0-rc5)
MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI>
CR: 28004428  XER: 00000000
CFAR: c0000000004ef180 SOFTE: 1
GPR00: c0000000004ef798 c0000001026bb310 c000000001157300 ffffffffffffffea
GPR04: 000000000000000a c0000001026bb130 0000000000000000 ffffffffffffffc0
GPR08: 00000000000000d1 0000000000000021 00000000ffffffd1 c000000000dd4990
GPR12: 0000000022004444 c00000000fe00800 0000000020000000 0000000000000000
GPR16: 0000000000000000 0000000043a606fc 0000000043a76c08 0000000043a1b3d0
GPR20: 000001002a35cd60 c0000001026bbb80 0000000000000000 0000000000000001
GPR24: 0000000000000240 0000000000000004 c00000062dc55000 0000000000000000
GPR28: 0000000000000004 c00000062ecd9200 0000000000000000 c0000001026bb6c0
NIP [c0000000004ef798] .assfail+0x28/0x30
LR [c0000000004ef798] .assfail+0x28/0x30
Call Trace:
[c0000001026bb310] [c0000000004ef798] .assfail+0x28/0x30 (unreliable)
[c0000001026bb380] [c000000000455d74] .xfs_alloc_space_available+0x194/0x1b0
[c0000001026bb410] [c00000000045b914] .xfs_alloc_fix_freelist+0x144/0x480
[c0000001026bb580] [c00000000045c368] .xfs_alloc_vextent+0x698/0xa90
[c0000001026bb650] [c0000000004a6200] .xfs_ialloc_ag_alloc+0x170/0x820
[c0000001026bb7c0] [c0000000004a9098] .xfs_dialloc+0x158/0x320
[c0000001026bb8a0] [c0000000004e628c] .xfs_ialloc+0x7c/0x610
[c0000001026bb990] [c0000000004e8138] .xfs_dir_ialloc+0xa8/0x2f0
[c0000001026bbaa0] [c0000000004e8814] .xfs_create+0x494/0x790
[c0000001026bbbf0] [c0000000004e5ebc] .xfs_generic_create+0x2bc/0x410
[c0000001026bbce0] [c0000000002b4a34] .vfs_mkdir+0x154/0x230
[c0000001026bbd70] [c0000000002bc444] .SyS_mkdirat+0x94/0x120
[c0000001026bbe30] [c00000000000b760] system_call+0x38/0xfc
Instruction dump:
4e800020 60000000 7c0802a6 7c862378 3c82ffca 7ca72b78 38841c18 7c651b78
38600000 f8010010 f821ff91 4bfff94d <0fe00000> 60000000 7c0802a6 7c892378

When block size is larger than inode cluster size, the call to
XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size) returns 0. Also, mkfs.xfs
would have set xfs_sb->sb_inoalignmt to 0. This causes
xfs_ialloc_cluster_alignment() to return 0.  Due to this
args.minalignslop (in xfs_ialloc_ag_alloc()) gets the unsigned
equivalent of -1 assigned to it. This later causes alloc_len in
xfs_alloc_space_available() to have a value of 0. In such a scenario
when args.total is also 0, the assert statement "ASSERT(args->maxlen >
0);" fails.

This commit fixes the bug by replacing the call to XFS_B_TO_FSBT() in
xfs_ialloc_cluster_alignment() with a call to xfs_icluster_size_fsb().

Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.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>
2017-02-16 17:20:38 -08:00
Brian Foster 75d65361cf xfs: split indlen reservations fairly when under reserved
Certain workoads that punch holes into speculative preallocation can
cause delalloc indirect reservation splits when the delalloc extent is
split in two. If further splits occur, an already short-handed extent
can be split into two in a manner that leaves zero indirect blocks for
one of the two new extents. This occurs because the shortage is large
enough that the xfs_bmap_split_indlen() algorithm completely drains the
requested indlen of one of the extents before it honors the existing
reservation.

This ultimately results in a warning from xfs_bmap_del_extent(). This
has been observed during file copies of large, sparse files using 'cp
--sparse=always.'

To avoid this problem, update xfs_bmap_split_indlen() to explicitly
apply the reservation shortage fairly between both extents. This smooths
out the overall indlen shortage and defers the situation where we end up
with a delalloc extent with zero indlen reservation to extreme
circumstances.

Reported-by: Patrick Dung <mpatdung@gmail.com>
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>
2017-02-16 17:20:12 -08:00
Brian Foster 0e339ef855 xfs: handle indlen shortage on delalloc extent merge
When a delalloc extent is created, it can be merged with pre-existing,
contiguous, delalloc extents. When this occurs,
xfs_bmap_add_extent_hole_delay() merges the extents along with the
associated indirect block reservations. The expectation here is that the
combined worst case indlen reservation is always less than or equal to
the indlen reservation for the individual extents.

This is not always the case, however, as existing extents can less than
the expected indlen reservation if the extent was previously split due
to a hole punch. If a new extent merges with such an extent, the total
indlen requirement may be larger than the sum of the indlen reservations
held by both extents.

xfs_bmap_add_extent_hole_delay() assumes that the worst case indlen
reservation is always available and assigns it to the merged extent
without consideration for the indlen held by the pre-existing extent. As
a result, the subsequent xfs_mod_fdblocks() call can attempt an
unintentional allocation rather than a free (indicated by an ASSERT()
failure). Further, if the allocation happens to fail in this context,
the failure goes unhandled and creates a filesystem wide block
accounting inconsistency.

Fix xfs_bmap_add_extent_hole_delay() to function as designed. Cap the
indlen reservation assigned to the merged extent to the sum of the
indlen reservations held by each of the individual extents.

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>
2017-02-16 17:20:12 -08:00
Christoph Hellwig ebf5587261 xfs: improve handling of busy extents in the low-level allocator
Currently we force the log and simply try again if we hit a busy extent,
but especially with online discard enabled it might take a while after
the log force for the busy extents to disappear, and we might have
already completed our second pass.

So instead we add a new waitqueue and a generation counter to the pag
structure so that we can do wakeups once we've removed busy extents,
and we replace the single retry with an unconditional one - after
all we hold the AGF buffer lock, so no other allocations or frees
can be racing with us in this AG.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-09 10:50:25 -08:00
Christoph Hellwig a14234c72b xfs: go straight to real allocations for direct I/O COW writes
When we allocate COW fork blocks for direct I/O writes we currently first
create a delayed allocation, and then convert it to a real allocation
once we've got the delayed one.

As there is no good reason for that this patch instead makes use call
xfs_bmapi_write from the COW allocation path.  The only interesting bits
are a few tweaks the low-level allocator to allow for this, most notably
the need to remove the call to xfs_bmap_extsize_align for the cowextsize
in xfs_bmap_btalloc - for the existing convert case it's a no-op, but
for the direct allocation case it would blow up our block reservation
way beyond what we reserved for the transaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-06 17:47:47 -08:00
Darrick J. Wong 05a630d76b xfs: allow unwritten extents in the CoW fork
In the data fork, we only allow extents to perform the following state
transitions:

delay -> real <-> unwritten

There's no way to move directly from a delalloc reservation to an
/unwritten/ allocated extent.  However, for the CoW fork we want to be
able to do the following to each extent:

delalloc -> unwritten -> written -> remapped to data fork

This will help us to avoid a race in the speculative CoW preallocation
code between a first thread that is allocating a CoW extent and a second
thread that is remapping part of a file after a write.  In order to do
this, however, we need two things: first, we have to be able to
transition from da to unwritten, and second the function that converts
between real and unwritten has to be made aware of the cow fork.  Do
both of those things.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:14:01 -08:00
Darrick J. Wong de14c5f541 xfs: verify free block header fields
Perform basic sanity checking of the directory free block header
fields so that we avoid hanging the system on invalid data.

(Granted that just means that now we shutdown on directory write,
but that seems better than hanging...)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:14:00 -08:00
Darrick J. Wong b3bf607d58 xfs: check for obviously bad level values in the bmbt root
We can't handle a bmbt that's taller than BTREE_MAXLEVELS, and there's
no such thing as a zero-level bmbt (for that we have extents format),
so if we see this, send back an error code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:59 -08:00
Darrick J. Wong d5a91baeb6 xfs: filter out obviously bad btree pointers
Don't let anybody load an obviously bad btree pointer.  Since the values
come from disk, we must return an error, not just ASSERT.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2017-02-02 15:13:58 -08:00
Darrick J. Wong 7a652bbe36 xfs: fail _dir_open when readahead fails
When we open a directory, we try to readahead block 0 of the directory
on the assumption that we're going to need it soon.  If the bmbt is
corrupt, the directory will never be usable and the readahead fails
immediately, so we might as well prevent the directory from being opened
at all.  This prevents a subsequent read or modify operation from
hitting it and taking the fs offline.

NOTE: We're only checking for early failures in the block mapping, not
the readahead directory block itself.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:58 -08:00
Darrick J. Wong 4b5bd5bf3f xfs: fix toctou race when locking an inode to access the data map
We use di_format and if_flags to decide whether we're grabbing the ilock
in btree mode (btree extents not loaded) or shared mode (anything else),
but the state of those fields can be changed by other threads that are
also trying to load the btree extents -- IFEXTENTS gets set before the
_bmap_read_extents call and cleared if it fails.

We don't actually need to have IFEXTENTS set until after the bmbt
records are successfully loaded and validated, which will fix the race
between multiple threads trying to read the same directory.  The next
patch strengthens directory bmbt validation by refusing to open the
directory if reading the bmbt to start directory readahead fails.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:57 -08:00