linux-stable.git/fs/xfs, branch linux-5.0.y

xfs: set buffer ops when repair probes for btree type

2019-02-03T22:03:59+00:00

In xrep_findroot_block, we work out the btree type and correctness of a
given block by calling different btree verifiers on root block
candidates.  However, we leave the NULL b_ops while ->verify_read
validates the block, which means that if the verifier calls
xfs_buf_verifier_error it'll crash on the null b_ops.  Fix it to set
b_ops before calling the verifier and unsetting it if the verifier
fails.

Furthermore, improve the documentation around xfs_buf_ensure_ops, which
is the function that is responsible for cleaning up the b_ops state of
buffers that go through xrep_findroot_block but don't match anything.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

xfs: end sync buffer I/O properly on shutdown error

2019-02-03T22:03:06+00:00

As of commit e339dd8d8b ("xfs: use sync buffer I/O for sync delwri
queue submission"), the delwri submission code uses sync buffer I/O
for sync delwri I/O. Instead of waiting on async I/O to unlock the
buffer, it uses the underlying sync I/O completion mechanism.

If delwri buffer submission fails due to a shutdown scenario, an
error is set on the buffer and buffer completion never occurs. This
can cause xfs_buf_delwri_submit() to deadlock waiting on a
completion event.

We could check the error state before waiting on such buffers, but
that doesn't serialize against the case of an error set via a racing
I/O completion. Instead, invoke I/O completion in the shutdown case
regardless of buffer I/O type.

Signed-off-by: Brian Foster 
Reviewed-by: Dave Chinner 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: eof trim writeback mapping as soon as it is cached

2019-02-03T22:02:49+00:00

The cached writeback mapping is EOF trimmed to try and avoid races
between post-eof block management and writeback that result in
sending cached data to a stale location. The cached mapping is
currently trimmed on the validation check, which leaves a race
window between the time the mapping is cached and when it is trimmed
against the current inode size.

For example, if a new mapping is cached by delalloc conversion on a
blocksize == page size fs, we could cycle various locks, perform
memory allocations, etc.  in the writeback codepath before the
associated mapping is eventually trimmed to i_size. This leaves
enough time for a post-eof truncate and file append before the
cached mapping is trimmed. The former event essentially invalidates
a range of the cached mapping and the latter bumps the inode size
such the trim on the next writepage event won't trim all of the
invalid blocks. fstest generic/464 reproduces this scenario
occasionally and causes a lost writeback and stale delalloc blocks
warning on inode inactivation.

To work around this problem, trim the cached writeback mapping as
soon as it is cached in addition to on subsequent validation checks.
This is a minor tweak to tighten the race window as much as possible
until a proper invalidation mechanism is available.

Fixes: 40214d128e07 ("xfs: trim writepage mapping to within eof")
Cc:  # v4.14+
Signed-off-by: Brian Foster 
Reviewed-by: Allison Henderson 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: xfs_fsops: drop useless LIST_HEAD

2018-12-29T18:47:58+00:00

Drop LIST_HEAD where the variable it declares is never used.

Commit 0410c3bb2b88 ("xfs: factor ag btree root block
initialisation") stopped using buffer_list and started using a
buffer list in an aghdr_init_data structure, but the declaration
of buffer_list was not removed.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
identifier x;
@@
- LIST_HEAD(x);
  ... when != x
// 

Fixes: 0410c3bb2b88 ("xfs: factor ag btree root block initialisation")
Signed-off-by: Julia Lawall 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: xfs_buf: drop useless LIST_HEAD

2018-12-29T18:47:34+00:00

Drop LIST_HEAD where the variable it declares has never
been used.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
identifier x;
@@
- LIST_HEAD(x);
  ... when != x
// 

Fixes: 26f1fe858f274 ("xfs: reduce lock hold times in buffer writeback")
Signed-off-by: Julia Lawall 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: reallocate realtime summary cache on growfs

2018-12-22T02:45:18+00:00

At mount time, we allocate m_rsum_cache with the number of realtime
bitmap blocks. However, xfs_growfs_rt() can increase the number of
realtime bitmap blocks. Using the cache after this happens may access
out of the bounds of the cache. Fix it by reallocating the cache in this
case.

Fixes: 355e3532132b ("xfs: cache minimum realtime summary level")
Signed-off-by: Omar Sandoval 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: stringify scrub types in ftrace output

2018-12-19T22:02:01+00:00

Use __print_symbolic to print the scrub type in ftrace output.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Eric Sandeen

xfs: stringify btree cursor types in ftrace output

2018-12-19T22:02:01+00:00

Use __print_symbolic to print the btree type in ftrace output.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Eric Sandeen

xfs: move XFS_INODE_FORMAT_STR mappings to libxfs

2018-12-19T22:02:01+00:00

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 
Reviewed-by: Eric Sandeen

xfs: move XFS_AG_BTREE_CMP_FORMAT_STR mappings to libxfs

2018-12-19T22:02:01+00:00

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 
Reviewed-by: Eric Sandeen