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When we discover written out buffer in transaction checkpoint list we
don't have to recheck validity of a transaction. Either this is the
last buffer in a transaction - and then we are done - or this isn't
and then we can just take another buffer from the checkpoint list
without dropping j_list_lock.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The __jbd2_journal_remove_checkpoint() doesn't require an elevated
b_count; indeed, until the jh structure gets released by the call to
jbd2_journal_put_journal_head(), the bh's b_count is elevated by
virtue of the existence of the jh structure.
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Having done a full regression test, we can now drop the
DELALLOC_RESERVED state flag.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented
because it was too hard to make sure the mballoc and get_block flags
could be reliably passed down through all of the codepaths that end up
calling ext4_mb_new_blocks().
Since then, we have mb_flags passed down through most of the code
paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky
as it used to.
This commit plumbs in the last of what is required, and then adds a
WARN_ON check to make sure we haven't missed anything. If this passes
a full regression test run, we can then drop
EXT4_STATE_DELALLOC_RESERVED.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Instead of initializing the allocation_request structure in
ext4_alloc_branch(), set it up in ext4_ind_map_blocks(), and then pass
it to ext4_alloc_branch() and ext4_splice_branch().
This allows ext4_ind_map_blocks to pass flags in the allocation
request structure without having to add Yet Another argument to
ext4_alloc_branch().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
This commit adds some statictics in extent status tree shrinker. The
purpose to add these is that we want to collect more details when we
encounter a stall caused by extent status tree shrinker. Here we count
the following statictics:
stats:
the number of all objects on all extent status trees
the number of reclaimable objects on lru list
cache hits/misses
the last sorted interval
the number of inodes on lru list
average:
scan time for shrinking some objects
the number of shrunk objects
maximum:
the inode that has max nr. of objects on lru list
the maximum scan time for shrinking some objects
The output looks like below:
$ cat /proc/fs/ext4/sda1/es_shrinker_info
stats:
28228 objects
6341 reclaimable objects
5281/631 cache hits/misses
586 ms last sorted interval
250 inodes on lru list
average:
153 us scan time
128 shrunk objects
maximum:
255 inode (255 objects, 198 reclaimable)
125723 us max scan time
If the lru list has never been sorted, the following line will not be
printed:
586ms last sorted interval
If there is an empty lru list, the following lines also will not be
printed:
250 inodes on lru list
...
maximum:
255 inode (255 objects, 198 reclaimable)
0 us max scan time
Meanwhile in this commit a new trace point is defined to print some
details in __ext4_es_shrink().
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit improves the trace point of extents status tree. We rename
trace_ext4_es_shrink_enter in ext4_es_count() because it is also used
in ext4_es_scan() and we can not identify them from the result.
Further this commit fixes a variable name in trace point in order to
keep consistency with others.
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Enable by default the block_validity feature, which checks for
collisions between newly allocated blocks and critical system
metadata.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
__wait_cp_io() is only called by jbd2_log_do_checkpoint(). Fold it in
to make it a bit easier to understand.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
__process_buffer() is only called by jbd2_log_do_checkpoint(), and it
had a very complex locking protocol where it would be called with the
j_list_lock, and sometimes exit with the lock held (if the return code
was 0), or release the lock.
This was confusing both to humans and to smatch (which erronously
complained that the lock was taken twice).
Folding __process_buffer() to the caller allows us to simplify the
control flow, making the resulting function easier to read and reason
about, and dropping the compiled size of fs/jbd2/checkpoint.c by 150
bytes (over 4% of the text size).
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Reuse the path object in ext4_move_extents() so we don't unnecessarily
free and reallocate it.
Also clean up the get_ext_path() wrapper so that it has the same
semantics of freeing the path object on error as ext4_ext_find_extent().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Now that the semantics of ext4_ext_find_extent() are much cleaner,
it's safe and more efficient to reuse the path object across the
multiple calls to ext4_ext_find_extent() in ext4_ext_shift_extents().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This adds additional safety in case for some reason we end reusing a
path structure which isn't big enough for current depth of the inode.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Teach ext4_ext_drop_refs() to accept a NULL argument, much like
kfree(). This allows us to drop a lot of checks to make sure path is
non-NULL before calling ext4_ext_drop_refs().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In nearly all of the calls to ext4_ext_find_extent() where the caller
is trying to recycle the path object, ext4_ext_drop_refs() gets called
to release the buffer heads before the path object gets overwritten.
To simplify things for the callers, and to avoid the possibility of a
memory leak, make ext4_ext_find_extent() responsible for dropping the
buffers.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Drop EXT4_EX_NOFREE_ON_ERR from ext4_ext_create_new_leaf(),
ext4_split_extent(), ext4_convert_unwritten_extents_endio().
This requires fixing all of their callers to potentially
ext4_ext_find_extent() to free the struct ext4_ext_path object in case
of an error, and there are interlocking dependencies all the way up to
ext4_ext_map_blocks(), ext4_swap_extents(), and
ext4_ext_remove_space().
Once this is done, we can drop the EXT4_EX_NOFREE_ON_ERR flag since it
is no longer necessary.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The function ext4_convert_initialized_extents() is only called by a
single function --- ext4_ext_convert_initalized_extents(). Inline the
code and get rid of the unnecessary bits in order to simplify the code.
Rename ext4_ext_convert_initalized_extents() to
convert_initalized_extents() since it's a static function that is
actually only used in a single caller, ext4_ext_map_blocks().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Right now, there are a places where it is all to easy to leak memory
on an error path, via a usage like this:
struct ext4_ext_path *path = NULL
while (...) {
...
path = ext4_ext_find_extent(inode, block, path, 0);
if (IS_ERR(path)) {
/* oops, if path was non-NULL before the call to
ext4_ext_find_extent, we've leaked it! :-( */
...
return PTR_ERR(path);
}
...
}
Unfortunately, there some code paths where we are doing the following
instead:
path = ext4_ext_find_extent(inode, block, orig_path, 0);
and where it's important that we _not_ free orig_path in the case
where ext4_ext_find_extent() returns an error.
So change the function signature of ext4_ext_find_extent() so that it
takes a struct ext4_ext_path ** for its third argument, and by
default, on an error, it will free the struct ext4_ext_path, and then
zero out the struct ext4_ext_path * pointer. In order to avoid
causing problems, we add a flag EXT4_EX_NOFREE_ON_ERR which causes
ext4_ext_find_extent() to use the original behavior of forcing the
caller to deal with freeing the original path pointer on the error
case.
The goal is to get rid of EXT4_EX_NOFREE_ON_ERR entirely, but this
allows for a gentle transition and makes the patches easier to verify.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Commit b8a8684502 introduced an accidental flag aliasing between
EXT4_EX_NOCACHE and EXT4_GET_BLOCKS_CONVERT_UNWRITTEN.
Fortunately, this didn't introduce any untorward side effects --- we
got lucky. Nevertheless, fix this and leave a warning to hopefully
avoid this from happening in the future.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We accidently aliased EXT4_EX_NOCACHE and EXT4_GET_CONVERT_UNWRITTEN
falgs, which apparently was hiding a bug that was unmasked when this
flag aliasing issue was addressed (see the subsequent commit). The
reproduction case was:
fsx -N 10000 -l 500000 -r 4096 -t 4096 -w 4096 -Z -R -W /vdb/junk
... which would cause fsx to report corruption in the data file.
The fix we have is a bit of an overkill, but I'd much rather be
conservative for now, and we can optimize ZERO_RANGE_FL handling
later. The fact that we need to zap the extent_status cache for the
inode is unfortunate, but correctness is far more important than
performance.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
If ext4_ext_find_extent() returns an error, we have to clear path1 or
path2 or else we would end up trying to free an ERR_PTR, which would
be bad.
Also eliminate some redundant code and mark the error paths as unlikely()
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_move_extents is too complex for review. It has duplicate almost
each function available in the rest of other codebase. It has useless
artificial restriction orig_offset == donor_offset. But in fact logic
of ext4_move_extents is very simple:
Iterate extents one by one (similar to ext4_fill_fiemap_extents)
->Iterate each page covered extent (similar to generic_perform_write)
->swap extents for covered by page (can be shared with IOC_MOVE_DATA)
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This allows us to make mext_next_extent static and potentially get rid
of it.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_journal_get_write_access() has just been called in ext4_append()
calling it again here is duplicated.
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
allocation failures, and to fix some journaling bugs involving journal
checksums and FALLOC_FL_ZERO_RANGE.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bugfixes from Ted Ts'o:
"Ext4 bug fixes for 3.17, to provide better handling of memory
allocation failures, and to fix some journaling bugs involving
journal checksums and FALLOC_FL_ZERO_RANGE"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix same-dir rename when inline data directory overflows
jbd2: fix descriptor block size handling errors with journal_csum
jbd2: fix infinite loop when recovering corrupt journal blocks
ext4: update i_disksize coherently with block allocation on error path
ext4: fix transaction issues for ext4_fallocate and ext_zero_range
ext4: fix incorect journal credits reservation in ext4_zero_range
ext4: move i_size,i_disksize update routines to helper function
ext4: fix BUG_ON in mb_free_blocks()
ext4: propagate errors up to ext4_find_entry()'s callers
When performing a same-directory rename, it's possible that adding or
setting the new directory entry will cause the directory to overflow
the inline data area, which causes the directory to be converted to an
extent-based directory. Under this circumstance it is necessary to
re-read the directory when deleting the old dirent because the "old
directory" context still points to i_block in the inode table, which
is now an extent tree root! The delete fails with an FS error, and
the subsequent fsck complains about incorrect link counts and
hardlinked directories.
Test case (originally found with flat_dir_test in the metadata_csum
test program):
# mkfs.ext4 -O inline_data /dev/sda
# mount /dev/sda /mnt
# mkdir /mnt/x
# touch /mnt/x/changelog.gz /mnt/x/copyright /mnt/x/README.Debian
# sync
# for i in /mnt/x/*; do mv $i $i.longer; done
# ls -la /mnt/x/
total 0
-rw-r--r-- 1 root root 0 Aug 25 12:03 changelog.gz.longer
-rw-r--r-- 1 root root 0 Aug 25 12:03 copyright
-rw-r--r-- 1 root root 0 Aug 25 12:03 copyright.longer
-rw-r--r-- 1 root root 0 Aug 25 12:03 README.Debian.longer
(Hey! Why are there four files now??)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
It turns out that there are some serious problems with the on-disk
format of journal checksum v2. The foremost is that the function to
calculate descriptor tag size returns sizes that are too big. This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.
Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.
Add a few function helpers so we don't have to open-code quite so
many pieces.
Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
When recovering the journal, don't fall into an infinite loop if we
encounter a corrupt journal block. Instead, just skip the block and
return an error, which fails the mount and thus forces the user to run
a full filesystem fsck.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
In case of delalloc block i_disksize may be less than i_size. So we
have to update i_disksize each time we allocated and submitted some
blocks beyond i_disksize. We weren't doing this on the error paths,
so fix this.
testcase: xfstest generic/019
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
After commit f282ac19d8 we use different transactions for
preallocation and i_disksize update which result in complain from fsck
after power-failure. spotted by generic/019. IMHO this is regression
because fs becomes inconsistent, even more 'e2fsck -p' will no longer
works (which drives admins go crazy) Same transaction requirement
applies ctime,mtime updates
testcase: xfstest generic/019
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Currently we reserve only 4 blocks but in worst case scenario
ext4_zero_partial_blocks() may want to zeroout and convert two
non adjacent blocks.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Pull btrfs fixes from Chris Mason:
"The biggest of these comes from Liu Bo, who tracked down a hang we've
been hitting since moving to kernel workqueues (it's a btrfs bug, not
in the generic code). His patch needs backporting to 3.16 and 3.15
stable, which I'll send once this is in.
Otherwise these are assorted fixes. Most were integrated last week
during KS, but I wanted to give everyone the chance to test the
result, so I waited for rc2 to come out before sending"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
Btrfs: fix task hang under heavy compressed write
Btrfs: fix filemap_flush call in btrfs_file_release
Btrfs: fix crash on endio of reading corrupted block
btrfs: fix leak in qgroup_subtree_accounting() error path
btrfs: Use right extent length when inserting overlap extent map.
Btrfs: clone, don't create invalid hole extent map
Btrfs: don't monopolize a core when evicting inode
Btrfs: fix hole detection during file fsync
Btrfs: ensure tmpfile inode is always persisted with link count of 0
Btrfs: race free update of commit root for ro snapshots
Btrfs: fix regression of btrfs device replace
Btrfs: don't consider the missing device when allocating new chunks
Btrfs: Fix wrong device size when we are resizing the device
Btrfs: don't write any data into a readonly device when scrub
Btrfs: Fix the problem that the replace destroys the seed filesystem
btrfs: Return right extent when fiemap gives unaligned offset and len.
Btrfs: fix wrong extent mapping for DirectIO
Btrfs: fix wrong write range for filemap_fdatawrite_range()
Btrfs: fix wrong missing device counter decrease
Btrfs: fix unzeroed members in fs_devices when creating a fs from seed fs
...
Highlights:
- More fixes for read/write codepath regressions
- Sleeping while holding the inode lock
- Stricter enforcement of page contiguity when coalescing requests
- Fix up error handling in the page coalescing code
- Don't busy wait on SIGKILL in the file locking code
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Merge tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client fixes from Trond Myklebust:
"Highlights:
- more fixes for read/write codepath regressions
* sleeping while holding the inode lock
* stricter enforcement of page contiguity when coalescing requests
* fix up error handling in the page coalescing code
- don't busy wait on SIGKILL in the file locking code"
* tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
nfs: Don't busy-wait on SIGKILL in __nfs_iocounter_wait
nfs: can_coalesce_requests must enforce contiguity
nfs: disallow duplicate pages in pgio page vectors
nfs: don't sleep with inode lock in lock_and_join_requests
nfs: fix error handling in lock_and_join_requests
nfs: use blocking page_group_lock in add_request
nfs: fix nonblocking calls to nfs_page_group_lock
nfs: change nfs_page_group_lock argument
As reported by Dan Aloni, commit f8567a3845 ("aio: fix aio request
leak when events are reaped by userspace") introduces a regression when
user code attempts to perform io_submit() with more events than are
available in the ring buffer. Reverting that commit would reintroduce a
regression when user space event reaping is used.
Fixing this bug is a bit more involved than the previous attempts to fix
this regression. Since we do not have a single point at which we can
count events as being reaped by user space and io_getevents(), we have
to track event completion by looking at the number of events left in the
event ring. So long as there are as many events in the ring buffer as
there have been completion events generate, we cannot call
put_reqs_available(). The code to check for this is now placed in
refill_reqs_available().
A test program from Dan and modified by me for verifying this bug is available
at http://www.kvack.org/~bcrl/20140824-aio_bug.c .
Reported-by: Dan Aloni <dan@kernelim.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Dan Aloni <dan@kernelim.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: stable@vger.kernel.org # v3.16 and anything that f8567a3845 was backported to
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This has been reported and discussed for a long time, and this hang occurs in
both 3.15 and 3.16.
Btrfs now migrates to use kernel workqueue, but it introduces this hang problem.
Btrfs has a kind of work queued as an ordered way, which means that its
ordered_func() must be processed in the way of FIFO, so it usually looks like --
normal_work_helper(arg)
work = container_of(arg, struct btrfs_work, normal_work);
work->func() <---- (we name it work X)
for ordered_work in wq->ordered_list
ordered_work->ordered_func()
ordered_work->ordered_free()
The hang is a rare case, first when we find free space, we get an uncached block
group, then we go to read its free space cache inode for free space information,
so it will
file a readahead request
btrfs_readpages()
for page that is not in page cache
__do_readpage()
submit_extent_page()
btrfs_submit_bio_hook()
btrfs_bio_wq_end_io()
submit_bio()
end_workqueue_bio() <--(ret by the 1st endio)
queue a work(named work Y) for the 2nd
also the real endio()
So the hang occurs when work Y's work_struct and work X's work_struct happens
to share the same address.
A bit more explanation,
A,B,C -- struct btrfs_work
arg -- struct work_struct
kthread:
worker_thread()
pick up a work_struct from @worklist
process_one_work(arg)
worker->current_work = arg; <-- arg is A->normal_work
worker->current_func(arg)
normal_work_helper(arg)
A = container_of(arg, struct btrfs_work, normal_work);
A->func()
A->ordered_func()
A->ordered_free() <-- A gets freed
B->ordered_func()
submit_compressed_extents()
find_free_extent()
load_free_space_inode()
... <-- (the above readhead stack)
end_workqueue_bio()
btrfs_queue_work(work C)
B->ordered_free()
As if work A has a high priority in wq->ordered_list and there are more ordered
works queued after it, such as B->ordered_func(), its memory could have been
freed before normal_work_helper() returns, which means that kernel workqueue
code worker_thread() still has worker->current_work pointer to be work
A->normal_work's, ie. arg's address.
Meanwhile, work C is allocated after work A is freed, work C->normal_work
and work A->normal_work are likely to share the same address(I confirmed this
with ftrace output, so I'm not just guessing, it's rare though).
When another kthread picks up work C->normal_work to process, and finds our
kthread is processing it(see find_worker_executing_work()), it'll think
work C as a collision and skip then, which ends up nobody processing work C.
So the situation is that our kthread is waiting forever on work C.
Besides, there're other cases that can lead to deadlock, but the real problem
is that all btrfs workqueue shares one work->func, -- normal_work_helper,
so this makes each workqueue to have its own helper function, but only a
wraper pf normal_work_helper.
With this patch, I no long hit the above hang.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
If we suffer a block allocation failure (for example due to a memory
allocation failure), it's possible that we will call
ext4_discard_allocated_blocks() before we've actually allocated any
blocks. In that case, fe_len and fe_start in ac->ac_f_ex will still
be zero, and this will result in mb_free_blocks(inode, e4b, 0, 0)
triggering the BUG_ON on mb_free_blocks():
BUG_ON(last >= (sb->s_blocksize << 3));
Fix this by bailing out of ext4_discard_allocated_blocks() if fs_len
is zero.
Also fix a missing ext4_mb_unload_buddy() call in
ext4_discard_allocated_blocks().
Google-Bug-Id: 16844242
Fixes: 86f0afd463
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
If we run into some kind of error, such as ENOMEM, while calling
ext4_getblk() or ext4_dx_find_entry(), we need to make sure this error
gets propagated up to ext4_find_entry() and then to its callers. This
way, transient errors such as ENOMEM can get propagated to the VFS.
This is important so that the system calls return the appropriate
error, and also so that in the case of ext4_lookup(), we return an
error instead of a NULL inode, since that will result in a negative
dentry cache entry that will stick around long past the OOM condition
which caused a transient ENOMEM error.
Google-Bug-Id: #17142205
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
If a SIGKILL is sent to a task waiting in __nfs_iocounter_wait,
it will busy-wait or soft lockup in its while loop.
nfs_wait_bit_killable won't sleep, and the loop won't exit on
the error return.
Stop the busy-wait by breaking out of the loop when
nfs_wait_bit_killable returns an error.
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Commit 6094f83864
"nfs: allow coalescing of subpage requests" got rid of the requirement
that requests cover whole pages, but it made some incorrect assumptions.
It turns out that callers of this interface can map adjacent requests
(by file position as seen by req_offset + req->wb_bytes) to different pages,
even when they could share a page. An example is the direct I/O interface -
iov_iter_get_pages_alloc may return one segment with a partial page filled
and the next segment (which is adjacent in the file position) starts with a
new page.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Adjacent requests that share the same page are allowed, but should only
use one entry in the page vector. This avoids overruning the page
vector - it is sized based on how many bytes there are, not by
request count.
This fixes issues that manifest as "Redzone overwritten" bugs (the
vector overrun) and hangs waiting on page read / write, as it waits on
the same page more than once.
This also adds bounds checking to the page vector with a graceful failure
(WARN_ON_ONCE and pgio error returned to application).
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
