When servicing mmap() reads from file holes the current DAX code
allocates a page cache page of all zeroes and places the struct page
pointer in the mapping->page_tree radix tree.
This has three major drawbacks:
1) It consumes memory unnecessarily. For every 4k page that is read via
a DAX mmap() over a hole, we allocate a new page cache page. This
means that if you read 1GiB worth of pages, you end up using 1GiB of
zeroed memory. This is easily visible by looking at the overall
memory consumption of the system or by looking at /proc/[pid]/smaps:
7f62e72b3000-7f63272b3000 rw-s 00000000 103:00 12 /root/dax/data
Size: 1048576 kB
Rss: 1048576 kB
Pss: 1048576 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 1048576 kB
Private_Dirty: 0 kB
Referenced: 1048576 kB
Anonymous: 0 kB
LazyFree: 0 kB
AnonHugePages: 0 kB
ShmemPmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Locked: 0 kB
2) It is slower than using a common zero page because each page fault
has more work to do. Instead of just inserting a common zero page we
have to allocate a page cache page, zero it, and then insert it. Here
are the average latencies of dax_load_hole() as measured by ftrace on
a random test box:
Old method, using zeroed page cache pages: 3.4 us
New method, using the common 4k zero page: 0.8 us
This was the average latency over 1 GiB of sequential reads done by
this simple fio script:
[global]
size=1G
filename=/root/dax/data
fallocate=none
[io]
rw=read
ioengine=mmap
3) The fact that we had to check for both DAX exceptional entries and
for page cache pages in the radix tree made the DAX code more
complex.
Solve these issues by following the lead of the DAX PMD code and using a
common 4k zero page instead. As with the PMD code we will now insert a
DAX exceptional entry into the radix tree instead of a struct page
pointer which allows us to remove all the special casing in the DAX
code.
Note that we do still pretty aggressively check for regular pages in the
DAX radix tree, especially where we take action based on the bits set in
the page. If we ever find a regular page in our radix tree now that
most likely means that someone besides DAX is inserting pages (which has
happened lots of times in the past), and we want to find that out early
and fail loudly.
This solution also removes the extra memory consumption. Here is that
same /proc/[pid]/smaps after 1GiB of reading from a hole with the new
code:
7f2054a74000-7f2094a74000 rw-s 00000000 103:00 12 /root/dax/data
Size: 1048576 kB
Rss: 0 kB
Pss: 0 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 0 kB
Referenced: 0 kB
Anonymous: 0 kB
LazyFree: 0 kB
AnonHugePages: 0 kB
ShmemPmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Locked: 0 kB
Overall system memory consumption is similarly improved.
Another major change is that we remove dax_pfn_mkwrite() from our fault
flow, and instead rely on the page fault itself to make the PTE dirty
and writeable. The following description from the patch adding the
vm_insert_mixed_mkwrite() call explains this a little more:
"To be able to use the common 4k zero page in DAX we need to have our
PTE fault path look more like our PMD fault path where a PTE entry
can be marked as dirty and writeable as it is first inserted rather
than waiting for a follow-up dax_pfn_mkwrite() =>
finish_mkwrite_fault() call.
Right now we can rely on having a dax_pfn_mkwrite() call because we
can distinguish between these two cases in do_wp_page():
case 1: 4k zero page => writable DAX storage
case 2: read-only DAX storage => writeable DAX storage
This distinction is made by via vm_normal_page(). vm_normal_page()
returns false for the common 4k zero page, though, just as it does
for DAX ptes. Instead of special casing the DAX + 4k zero page case
we will simplify our DAX PTE page fault sequence so that it matches
our DAX PMD sequence, and get rid of the dax_pfn_mkwrite() helper.
We will instead use dax_iomap_fault() to handle write-protection
faults.
This means that insert_pfn() needs to follow the lead of
insert_pfn_pmd() and allow us to pass in a 'mkwrite' flag. If
'mkwrite' is set insert_pfn() will do the work that was previously
done by wp_page_reuse() as part of the dax_pfn_mkwrite() call path"
Link: http://lkml.kernel.org/r/20170724170616.25810-4-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we fail a mount on account of cow recovery errors, it's possible that
a previous quotacheck left some dquots in memory. The bailout clause of
xfs_mountfs forgets to purge these, and so we leak them. Fix that.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Way back when we established inode block-map redo log items, it was
discovered that we needed to prevent the VFS from evicting inodes during
log recovery because any given inode might be have bmap redo items to
replay even if the inode has no link count and is ultimately deleted,
and any eviction of an unlinked inode causes the inode to be truncated
and freed too early.
To make this possible, we set MS_ACTIVE so that inodes would not be torn
down immediately upon release. Unfortunately, this also results in the
quota inodes not being released at all if a later part of the mount
process should fail, because we never reclaim the inodes. So, set
MS_ACTIVE right before we do the last part of log recovery and clear it
immediately after we finish the log recovery so that everything
will be torn down properly if we abort the mount.
Fixes: 17c12bcd30 ("xfs: when replaying bmap operations, don't let unlinked inodes get reaped")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
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>
According to the commit that implemented per-inode DAX flag:
commit 58f88ca2df ("xfs: introduce per-inode DAX enablement")
the flag is supposed to act as "inherit flag".
Currently this only works in the situations where parent directory
already has a flag in di_flags set, otherwise inheritance does not
work. This is because setting the XFS_DIFLAG2_DAX flag is done in a
wrong branch designated for di_flags, not di_flags2.
Fix this by moving the code to branch designated for setting di_flags2,
which does test for flags in di_flags2.
Fixes: 58f88ca2df ("xfs: introduce per-inode DAX enablement")
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The bio describing discard operation is allocated by
__blkdev_issue_discard() which returns us a reference to it. That
reference is never released and thus we leak this bio. Drop the bio
reference once it completes in xlog_discard_endio().
CC: stable@vger.kernel.org
Fixes: 4560e78f40
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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>
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>
If a dquot has an id of U32_MAX, the next lookup index increment
overflows the uint32_t back to 0. This starts the lookup sequence
over from the beginning, repeats indefinitely and results in a
livelock.
Update xfs_qm_dquot_walk() to explicitly check for the lookup
overflow and exit the loop.
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>
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>
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>
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>
- Add some locking assertions for the _ilock helpers.
- Revert the XFS_QMOPT_NOLOCK patch; after discussion with hch the
online fsck patch that would have needed it has been redesigned and
no longer needs it.
- Fix behavioral regression of SEEK_HOLE/DATA with negative offsets to match
4.12-era XFS behavior.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=M5uj
-----END PGP SIGNATURE-----
Merge tag 'xfs-4.13-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull XFS fixes from Darrick Wong:
"Largely debugging and regression fixes.
- Add some locking assertions for the _ilock helpers.
- Revert the XFS_QMOPT_NOLOCK patch; after discussion with hch the
online fsck patch that would have needed it has been redesigned and
no longer needs it.
- Fix behavioral regression of SEEK_HOLE/DATA with negative offsets
to match 4.12-era XFS behavior"
* tag 'xfs-4.13-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
vfs: in iomap seek_{hole,data}, return -ENXIO for negative offsets
Revert "xfs: grab dquots without taking the ilock"
xfs: assert locking precondition in xfs_readlink_bmap_ilocked
xfs: assert locking precondіtion in xfs_attr_list_int_ilocked
xfs: fixup xfs_attr_get_ilocked
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>
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>
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>
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>
KM_MAYFAIL didn't have any suitable GFP_FOO counterpart until recently
so it relied on the default page allocator behavior for the given set of
flags. This means that small allocations actually never failed.
Now that we have __GFP_RETRY_MAYFAIL flag which works independently on
the allocation request size we can map KM_MAYFAIL to it. The allocator
will try as hard as it can to fulfill the request but fails eventually
if the progress cannot be made. It does so without triggering the OOM
killer which can be seen as an improvement because KM_MAYFAIL users
should be able to deal with allocation failures.
Link: http://lkml.kernel.org/r/20170623085345.11304-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Avoid quotacheck deadlocks
- Fix transaction overflows when bunmapping fragmented files
- Refactor directory readahead
- Allow admin to configure if ASSERT is fatal
- Improve transaction usage detail logging during overflows
- Minor cleanups
- Don't leak log items when the log shuts down
- Remove double-underscore typedefs
- Various preparation for online scrubbing
- Introduce new error injection configuration sysfs knobs
- Refactor dq_get_next to use extent map directly
- Fix problems with iterating the page cache for unwritten data
- Implement SEEK_{HOLE,DATA} via iomap
- Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA
- Don't use MAXPATHLEN to check on-disk symlink target lengths
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=/GZI
-----END PGP SIGNATURE-----
Merge tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull XFS updates from Darrick Wong:
"Here are some changes for you for 4.13. For the most part it's fixes
for bugs and deadlock problems, and preparation for online fsck in
some future merge window.
- Avoid quotacheck deadlocks
- Fix transaction overflows when bunmapping fragmented files
- Refactor directory readahead
- Allow admin to configure if ASSERT is fatal
- Improve transaction usage detail logging during overflows
- Minor cleanups
- Don't leak log items when the log shuts down
- Remove double-underscore typedefs
- Various preparation for online scrubbing
- Introduce new error injection configuration sysfs knobs
- Refactor dq_get_next to use extent map directly
- Fix problems with iterating the page cache for unwritten data
- Implement SEEK_{HOLE,DATA} via iomap
- Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA
- Don't use MAXPATHLEN to check on-disk symlink target lengths"
* tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (48 commits)
xfs: don't crash on unexpected holes in dir/attr btrees
xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN
xfs: fix contiguous dquot chunk iteration livelock
xfs: Switch to iomap for SEEK_HOLE / SEEK_DATA
vfs: Add iomap_seek_hole and iomap_seek_data helpers
vfs: Add page_cache_seek_hole_data helper
xfs: remove a whitespace-only line from xfs_fs_get_nextdqblk
xfs: rewrite xfs_dq_get_next_id using xfs_iext_lookup_extent
xfs: Check for m_errortag initialization in xfs_errortag_test
xfs: grab dquots without taking the ilock
xfs: fix semicolon.cocci warnings
xfs: Don't clear SGID when inheriting ACLs
xfs: free cowblocks and retry on buffered write ENOSPC
xfs: replace log_badcrc_factor knob with error injection tag
xfs: convert drop_writes to use the errortag mechanism
xfs: remove unneeded parameter from XFS_TEST_ERROR
xfs: expose errortag knobs via sysfs
xfs: make errortag a per-mountpoint structure
xfs: free uncommitted transactions during log recovery
xfs: don't allow bmap on rt files
...
-----BEGIN PGP SIGNATURE-----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=3Z93
-----END PGP SIGNATURE-----
Merge tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull Writeback error handling updates from Jeff Layton:
"This pile represents the bulk of the writeback error handling fixes
that I have for this cycle. Some of the earlier patches in this pile
may look trivial but they are prerequisites for later patches in the
series.
The aim of this set is to improve how we track and report writeback
errors to userland. Most applications that care about data integrity
will periodically call fsync/fdatasync/msync to ensure that their
writes have made it to the backing store.
For a very long time, we have tracked writeback errors using two flags
in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a
writeback error occurs (via mapping_set_error) and are cleared as a
side-effect of filemap_check_errors (as you noted yesterday). This
model really sucks for userland.
Only the first task to call fsync (or msync or fdatasync) will see the
error. Any subsequent task calling fsync on a file will get back 0
(unless another writeback error occurs in the interim). If I have
several tasks writing to a file and calling fsync to ensure that their
writes got stored, then I need to have them coordinate with one
another. That's difficult enough, but in a world of containerized
setups that coordination may even not be possible.
But wait...it gets worse!
The calls to filemap_check_errors can be buried pretty far down in the
call stack, and there are internal callers of filemap_write_and_wait
and the like that also end up clearing those errors. Many of those
callers ignore the error return from that function or return it to
userland at nonsensical times (e.g. truncate() or stat()). If I get
back -EIO on a truncate, there is no reason to think that it was
because some previous writeback failed, and a subsequent fsync() will
(incorrectly) return 0.
This pile aims to do three things:
1) ensure that when a writeback error occurs that that error will be
reported to userland on a subsequent fsync/fdatasync/msync call,
regardless of what internal callers are doing
2) report writeback errors on all file descriptions that were open at
the time that the error occurred. This is a user-visible change,
but I think most applications are written to assume this behavior
anyway. Those that aren't are unlikely to be hurt by it.
3) document what filesystems should do when there is a writeback
error. Today, there is very little consistency between them, and a
lot of cargo-cult copying. We need to make it very clear what
filesystems should do in this situation.
To achieve this, the set adds a new data type (errseq_t) and then
builds new writeback error tracking infrastructure around that. Once
all of that is in place, we change the filesystems to use the new
infrastructure for reporting wb errors to userland.
Note that this is just the initial foray into cleaning up this mess.
There is a lot of work remaining here:
1) convert the rest of the filesystems in a similar fashion. Once the
initial set is in, then I think most other fs' will be fairly
simple to convert. Hopefully most of those can in via individual
filesystem trees.
2) convert internal waiters on writeback to use errseq_t for
detecting errors instead of relying on the AS_* flags. I have some
draft patches for this for ext4, but they are not quite ready for
prime time yet.
This was a discussion topic this year at LSF/MM too. If you're
interested in the gory details, LWN has some good articles about this:
https://lwn.net/Articles/718734/https://lwn.net/Articles/724307/"
* tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
btrfs: minimal conversion to errseq_t writeback error reporting on fsync
xfs: minimal conversion to errseq_t writeback error reporting
ext4: use errseq_t based error handling for reporting data writeback errors
fs: convert __generic_file_fsync to use errseq_t based reporting
block: convert to errseq_t based writeback error tracking
dax: set errors in mapping when writeback fails
Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors
mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error
fs: new infrastructure for writeback error handling and reporting
lib: add errseq_t type and infrastructure for handling it
mm: don't TestClearPageError in __filemap_fdatawait_range
mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails
jbd2: don't clear and reset errors after waiting on writeback
buffer: set errors in mapping at the time that the error occurs
fs: check for writeback errors after syncing out buffers in generic_file_fsync
buffer: use mapping_set_error instead of setting the flag
mm: fix mapping_set_error call in me_pagecache_dirty
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>
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>
Pull percpu updates from Tejun Heo:
"These are the percpu changes for the v4.13-rc1 merge window. There are
a couple visibility related changes - tracepoints and allocator stats
through debugfs, along with __ro_after_init markings and a cosmetic
rename in percpu_counter.
Please note that the simple O(#elements_in_the_chunk) area allocator
used by percpu allocator is again showing scalability issues,
primarily with bpf allocating and freeing large number of counters.
Dennis is working on the replacement allocator and the percpu
allocator will be seeing increased churns in the coming cycles"
* 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: fix static checker warnings in pcpu_destroy_chunk
percpu: fix early calls for spinlock in pcpu_stats
percpu: resolve err may not be initialized in pcpu_alloc
percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch
percpu: add tracepoint support for percpu memory
percpu: expose statistics about percpu memory via debugfs
percpu: migrate percpu data structures to internal header
percpu: add missing lockdep_assert_held to func pcpu_free_area
mark most percpu globals as __ro_after_init
Just check and advance the data errseq_t in struct file before
before returning from fsync on normal files. Internal filemap_*
callers are left as-is.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
The patch below updated xfs_dq_get_next_id() to use the XFS iext
lookup helpers to locate the next quota id rather than to seek for
data in the quota file. The updated code fails to correctly handle
the case where the quota inode might have contiguous chunks part of
the same extent. In this case, the start block offset is calculated
based on the next expected id but the extent lookup returns the same
start offset as for the previous chunk. This causes the returned id
to go backwards and livelocks the quota iteration. This problem is
reproduced intermittently by generic/232.
To handle this case, check whether the startoff from the extent
lookup is behind the startoff calculated from the next quota id. If
so, bump up got.br_startoff to the specific file offset that is
expected to hold the next dquot chunk.
Fixes: bda250dbaf ("xfs: rewrite xfs_dq_get_next_id using xfs_iext_lookup_extent")
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>
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Add the SYSTEM_SCHEDULING bootup state to move various scheduler
debug checks earlier into the bootup. This turns silent and
sporadically deadly bugs into nice, deterministic splats. Fix some
of the splats that triggered. (Thomas Gleixner)
- A round of restructuring and refactoring of the load-balancing and
topology code (Peter Zijlstra)
- Another round of consolidating ~20 of incremental scheduler code
history: this time in terms of wait-queue nomenclature. (I didn't
get much feedback on these renaming patches, and we can still
easily change any names I might have misplaced, so if anyone hates
a new name, please holler and I'll fix it.) (Ingo Molnar)
- sched/numa improvements, fixes and updates (Rik van Riel)
- Another round of x86/tsc scheduler clock code improvements, in hope
of making it more robust (Peter Zijlstra)
- Improve NOHZ behavior (Frederic Weisbecker)
- Deadline scheduler improvements and fixes (Luca Abeni, Daniel
Bristot de Oliveira)
- Simplify and optimize the topology setup code (Lauro Ramos
Venancio)
- Debloat and decouple scheduler code some more (Nicolas Pitre)
- Simplify code by making better use of llist primitives (Byungchul
Park)
- ... plus other fixes and improvements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
sched/cputime: Refactor the cputime_adjust() code
sched/debug: Expose the number of RT/DL tasks that can migrate
sched/numa: Hide numa_wake_affine() from UP build
sched/fair: Remove effective_load()
sched/numa: Implement NUMA node level wake_affine()
sched/fair: Simplify wake_affine() for the single socket case
sched/numa: Override part of migrate_degrades_locality() when idle balancing
sched/rt: Move RT related code from sched/core.c to sched/rt.c
sched/deadline: Move DL related code from sched/core.c to sched/deadline.c
sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled
sched/fair: Spare idle load balancing on nohz_full CPUs
nohz: Move idle balancer registration to the idle path
sched/loadavg: Generalize "_idle" naming to "_nohz"
sched/core: Drop the unused try_get_task_struct() helper function
sched/fair: WARN() and refuse to set buddy when !se->on_rq
sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well
sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c
sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h>
...
Pull core block/IO updates from Jens Axboe:
"This is the main pull request for the block layer for 4.13. Not a huge
round in terms of features, but there's a lot of churn related to some
core cleanups.
Note this depends on the UUID tree pull request, that Christoph
already sent out.
This pull request contains:
- A series from Christoph, unifying the error/stats codes in the
block layer. We now use blk_status_t everywhere, instead of using
different schemes for different places.
- Also from Christoph, some cleanups around request allocation and IO
scheduler interactions in blk-mq.
- And yet another series from Christoph, cleaning up how we handle
and do bounce buffering in the block layer.
- A blk-mq debugfs series from Bart, further improving on the support
we have for exporting internal information to aid debugging IO
hangs or stalls.
- Also from Bart, a series that cleans up the request initialization
differences across types of devices.
- A series from Goldwyn Rodrigues, allowing the block layer to return
failure if we will block and the user asked for non-blocking.
- Patch from Hannes for supporting setting loop devices block size to
that of the underlying device.
- Two series of patches from Javier, fixing various issues with
lightnvm, particular around pblk.
- A series from me, adding support for write hints. This comes with
NVMe support as well, so applications can help guide data placement
on flash to improve performance, latencies, and write
amplification.
- A series from Ming, improving and hardening blk-mq support for
stopping/starting and quiescing hardware queues.
- Two pull requests for NVMe updates. Nothing major on the feature
side, but lots of cleanups and bug fixes. From the usual crew.
- A series from Neil Brown, greatly improving the bio rescue set
support. Most notably, this kills the bio rescue work queues, if we
don't really need them.
- Lots of other little bug fixes that are all over the place"
* 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits)
lightnvm: pblk: set line bitmap check under debug
lightnvm: pblk: verify that cache read is still valid
lightnvm: pblk: add initialization check
lightnvm: pblk: remove target using async. I/Os
lightnvm: pblk: use vmalloc for GC data buffer
lightnvm: pblk: use right metadata buffer for recovery
lightnvm: pblk: schedule if data is not ready
lightnvm: pblk: remove unused return variable
lightnvm: pblk: fix double-free on pblk init
lightnvm: pblk: fix bad le64 assignations
nvme: Makefile: remove dead build rule
blk-mq: map all HWQ also in hyperthreaded system
nvmet-rdma: register ib_client to not deadlock in device removal
nvme_fc: fix error recovery on link down.
nvmet_fc: fix crashes on bad opcodes
nvme_fc: Fix crash when nvme controller connection fails.
nvme_fc: replace ioabort msleep loop with completion
nvme_fc: fix double calls to nvme_cleanup_cmd()
nvme-fabrics: verify that a controller returns the correct NQN
nvme: simplify nvme_dev_attrs_are_visible
...
- introduce the new uuid_t/guid_t types that are going to replace
the somewhat confusing uuid_be/uuid_le types and make the terminology
fit the various specs, as well as the userspace libuuid library.
(me, based on a previous version from Amir)
- consolidated generic uuid/guid helper functions lifted from XFS
and libnvdimm (Amir and me)
- conversions to the new types and helpers (Amir, Andy and me)
-----BEGIN PGP SIGNATURE-----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=J/4P
-----END PGP SIGNATURE-----
Merge tag 'uuid-for-4.13' of git://git.infradead.org/users/hch/uuid
Pull uuid subsystem from Christoph Hellwig:
"This is the new uuid subsystem, in which Amir, Andy and I have started
consolidating our uuid/guid helpers and improving the types used for
them. Note that various other subsystems have pulled in this tree, so
I'd like it to go in early.
UUID/GUID summary:
- introduce the new uuid_t/guid_t types that are going to replace the
somewhat confusing uuid_be/uuid_le types and make the terminology
fit the various specs, as well as the userspace libuuid library.
(me, based on a previous version from Amir)
- consolidated generic uuid/guid helper functions lifted from XFS and
libnvdimm (Amir and me)
- conversions to the new types and helpers (Amir, Andy and me)"
* tag 'uuid-for-4.13' of git://git.infradead.org/users/hch/uuid: (34 commits)
ACPI: hns_dsaf_acpi_dsm_guid can be static
mmc: sdhci-pci: make guid intel_dsm_guid static
uuid: Take const on input of uuid_is_null() and guid_is_null()
thermal: int340x_thermal: fix compile after the UUID API switch
thermal: int340x_thermal: Switch to use new generic UUID API
acpi: always include uuid.h
ACPI: Switch to use generic guid_t in acpi_evaluate_dsm()
ACPI / extlog: Switch to use new generic UUID API
ACPI / bus: Switch to use new generic UUID API
ACPI / APEI: Switch to use new generic UUID API
acpi, nfit: Switch to use new generic UUID API
MAINTAINERS: add uuid entry
tmpfs: generate random sb->s_uuid
scsi_debug: switch to uuid_t
nvme: switch to uuid_t
sysctl: switch to use uuid_t
partitions/ldm: switch to use uuid_t
overlayfs: use uuid_t instead of uuid_be
fs: switch ->s_uuid to uuid_t
ima/policy: switch to use uuid_t
...
Switch to the iomap_seek_hole and iomap_seek_data helpers for
implementing lseek SEEK_HOLE / SEEK_DATA, and remove all the
code that isn't needed any more.
Based on patches from Andreas Gruenbacher <agruenba@redhat.com>.
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>
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>
This goes straight to a single lookup in the extent list and avoids a
roundtrip through two layers that don't add any value for the simple
quoata file that just has data or holes and no page cache, delayed
allocation, unwritten extent or COW fork (which btw, doesn't seem to
be handled by the existing SEEK HOLE/DATA code).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-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>
While adding error injection into IO completion, I notice the lack of
initialization check in xfs_errortag_test(), make the error injection
mechanism unable to be used there.
IO completion is executed a few times before the error injection
mechanism is initialized, so to be safer, make xfs_errortag_test() check
if the errortag is properly initialized.
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>
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>
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.
Fix the problem by calling __xfs_set_acl() instead of xfs_set_acl() when
setting up inode in xfs_generic_create(). That prevents SGID bit
clearing and mode is properly set by posix_acl_create() anyway. We also
reorder arguments of __xfs_set_acl() to match the ordering of
xfs_set_acl() to make things consistent.
Fixes: 073931017b
CC: stable@vger.kernel.org
CC: Darrick J. Wong <darrick.wong@oracle.com>
CC: linux-xfs@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
XFS runs an eofblocks reclaim scan before returning an ENOSPC error to
userspace for buffered writes. This facilitates aggressive speculative
preallocation without causing user visible side effects such as
premature ENOSPC.
Run a cowblocks scan in the same situation to reclaim lingering COW fork
preallocation throughout the filesystem.
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>
Now that error injection tags support dynamic frequency adjustment,
replace the debug mode sysfs knob that controls log record CRC error
injection with an error injection tag.
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>
We now have enhanced error injection that can control the frequency
with which errors happen, so convert drop_writes to use this.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
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>
Creates a /sys/fs/xfs/$dev/errortag/ directory to control the errortag
values directly. This enables us to control the randomness values,
rather than having to accept the defaults.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Remove the xfs_etest structure in favor of a per-mountpoint structure.
This will give us the flexibility to set as many error injection points
as we want, and later enable us to set up sysfs knobs to set the trigger
frequency as we wish. This comes at a cost of higher memory use, but
unti we hit 1024 injection points (we're at 29) or a lot of mounts this
shouldn't be a huge issue.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Log recovery allocates in-core transaction and member item data
structures on-demand as it processes the on-disk log. Transactions
are allocated on first encounter on-disk and stored in a hash table
structure where they are easily accessible for subsequent lookups.
Transaction items are also allocated on demand and are attached to
the associated transactions.
When a commit record is encountered in the log, the transaction is
committed to the fs and the in-core structures are freed. If a
filesystem crashes or shuts down before all in-core log buffers are
flushed to the log, however, not all transactions may have commit
records in the log. As expected, the modifications in such an
incomplete transaction are not replayed to the fs. The in-core data
structures for the partial transaction are never freed, however,
resulting in a memory leak.
Update xlog_do_recovery_pass() to first correctly initialize the
hash table array so empty lists can be distinguished from populated
lists on function exit. Update xlog_recover_free_trans() to always
remove the transaction from the list prior to freeing the associated
memory. Finally, walk the hash table of transaction lists as the
last step before it goes out of scope and free any transactions that
may remain on the lists. This prevents a memory leak of partial
transactions in the log.
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>
- don't allow swapon on files on the realtime device, because the swap
code will swap pages out to blocks on the data device, thereby
corrupting the filesystem
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=qkCp
-----END PGP SIGNATURE-----
Merge tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
"I have one more bugfix for you for 4.12-rc7 to fix a disk corruption
problem:
- don't allow swapon on files on the realtime device, because the
swap code will swap pages out to blocks on the data device, thereby
corrupting the filesystem"
* tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: don't allow bmap on rt files
bmap returns a dumb LBA address but not the block device that goes with
that LBA. Swapfiles don't care about this and will blindly assume that
the data volume is the correct blockdev, which is totally bogus for
files on the rt subvolume. This results in the swap code doing IOs to
arbitrary locations on the data device(!) if the passed in mapping is a
realtime file, so just turn off bmap for rt files.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Currently, percpu_counter_add is a wrapper around __percpu_counter_add
which is preempt safe due to explicit calls to preempt_disable. Given
how __ prefix is used in percpu related interfaces, the naming
unfortunately creates the false sense that __percpu_counter_add is
less safe than percpu_counter_add. In terms of context-safety,
they're equivalent. The only difference is that the __ version takes
a batch parameter.
Make this a bit more explicit by just renaming __percpu_counter_add to
percpu_counter_add_batch.
This patch doesn't cause any functional changes.
tj: Minor updates to patch description for clarity. Cosmetic
indentation updates.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: linux-mm@kvack.org
Cc: "David S. Miller" <davem@davemloft.net>
bmap returns a dumb LBA address but not the block device that goes with
that LBA. Swapfiles don't care about this and will blindly assume that
the data volume is the correct blockdev, which is totally bogus for
files on the rt subvolume. This results in the swap code doing IOs to
arbitrary locations on the data device(!) if the passed in mapping is a
realtime file, so just turn off bmap for rt files.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Expose the readlink variant that doesn't take the inode lock so that
the scrubber can inspect symlink contents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
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>
