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Whenever we encounter corrupt realtime metadat blocks, we should report
that to the health monitoring system for later reporting.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
To use the new rwsem_assert_held()/rwsem_assert_held_write(), we can't
use the existing ASSERT macro. Add a new xfs_assert_ilocked() and
convert all the callers.
Fix an apparent bug in xfs_isilocked(): If the caller specifies
XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL, xfs_assert_ilocked() will check both
the IOLOCK and the ILOCK are held for write. xfs_isilocked() only
checked that the ILOCK was held for write.
xfs_assert_ilocked() is always on, even if DEBUG or XFS_WARN aren't
defined. It's a cheap check, so I don't think it's worth defining
it away.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The remaining callers of kmem_free() are freeing heap memory, so
we can convert them directly to kfree() and get rid of kmem_free()
altogether.
This conversion was done with:
$ for f in `git grep -l kmem_free fs/xfs`; do
> sed -i s/kmem_free/kfree/ $f
> done
$
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Start getting rid of kmem_free() by converting all the cases where
memory can come from vmalloc interfaces to calling kvfree()
directly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
kmem_alloc() is just a thin wrapper around kmalloc() these days.
Convert everything to use kmalloc() so we can get rid of the
wrapper.
Note: the transaction region allocation in xlog_add_to_transaction()
can be a high order allocation. Converting it to use
kmalloc(__GFP_NOFAIL) results in warnings in the page allocation
code being triggered because the mm subsystem does not want us to
use __GFP_NOFAIL with high order allocations like we've been doing
with the kmem_alloc() wrapper for a couple of decades. Hence this
specific case gets converted to xlog_kvmalloc() rather than
kmalloc() to avoid this issue.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
There isn't really much left in xfs_rtallocate_extent now, fold it into
the only caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
There are currently multiple levels of fall back if an RT allocation
can not be satisfied:
1) xfs_rtallocate_extent extends the minlen and reduces the maxlen due
to the extent size hint. If that can't be done, it return -ENOSPC
and let's xfs_bmap_rtalloc retry, which then not only drops the
extent size hint based alignment, but also the minlen adjustment
2) if xfs_rtallocate_extent gets -ENOSPC from the underlying functions,
it only drops the extent size hint based alignment and retries
3) if that still does not succeed, xfs_rtallocate_extent drops the
extent size hint (which is a complex no-op at this point) and the
minlen using the same code as (1) above
4) if that still doesn't success and the caller wanted an allocation
near a blkno, drop that blkno hint.
The handling in 1 is rather inefficient as we could just drop the
alignment and continue, and 2/3 interact in really weird ways due to
the duplicate policy.
Move aligning the min and maxlen out of xfs_rtallocate_extent and into
a helper called directly by xfs_bmap_rtalloc. This allows just
continuing with the allocation if we have to drop the alignment instead
of going through the retry loop and also dropping the perfectly usable
minlen adjustment that didn't cause the problem, and then just use
a single retry that drops both the minlen and alignment requirement
when we really are out of space, thus consolidating cases (2) and (3)
above.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_bmap_rtalloc is a bit of a mess in terms of calculating the locally
need variables. Reorder them a bit so that related code is located
next to each other - the raminlen calculation moves up next to where
the maximum len is calculated, and all the prod calculation is move
into a single place and rearranged so that the real prod calculation
only happens when it actually is needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Use the kernel min/max helpers instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_format.h has a bunch odd wrappers for helper functions and mount
structure access using RT* prefixes. Replace them with their open coded
versions (for those that weren't entirely unused) and remove the wrappers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_rtallocate_extent_size has two loops with nearly identical logic
in them. Split that logic into a separate xfs_rtalloc_sumlevel helper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Use common code for both xfs_rtallocate_range calls by moving
the !isfree logic into the non-default branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Use a goto to use a common tail for the case of being able to allocate
an extent.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Change polarity of a check so that the successful case of being able to
allocate an extent is in the main path of the function and error handling
is on a branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Doing a break in the else side of a conditional is rather silly. Invert
the check, break ASAP and unindent the other leg.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_rtmodify_summary_int is only used inside xfs_rtbitmap.c and to
implement xfs_rtget_summary. Move xfs_rtget_summary to xfs_rtbitmap.c
as the exported API and mark xfs_rtmodify_summary_int static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Clean up the logical in xfs_bmap_rtalloc that tries to find a rtextent
to start the search from by using a separate variable for the hint, not
calling xfs_bmap_adjacent when we want to ignore the locality and avoid
an extra roundtrip converting between block numbers and RT extent
numbers.
As a side-effect this doesn't pointlessly call xfs_rtpick_extent and
increment the start rtextent hint if we are going to ignore the result
anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Reorder the tail end of xfs_bmap_rtalloc so that the successfully
allocation is in the main path, and the error handling is on a branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Just return -ENOSPC instead of returning 0 and setting the return rt
extent number to NULLRTEXTNO. This is turn removes all users of
NULLRTEXTNO, so remove that as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_bmap_rtalloc is currently in xfs_bmap_util.c, which is a somewhat
odd spot for it, given that is only called from xfs_bmap.c and calls
into xfs_rtalloc.c to do the actual work. Move xfs_bmap_rtalloc to
xfs_rtalloc.c and mark xfs_rtpick_extent xfs_rtallocate_extent and
xfs_rtallocate_extent static now that they aren't called from outside
of xfs_rtalloc.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
minlen is the lower bound on the extent length that the caller can
accept, and maxlen is at this point the maximal available length.
This means a minlen extent is perfectly fine to use, so do it. This
matches the equivalent logic in xfs_rtallocate_extent_exact that also
accepts a minlen sized extent.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
While playing with growfs to create a 20TB realtime section on a
filesystem that didn't previously have an rt section, I noticed that
growfs would occasionally shut down the log due to a transaction
reservation overflow.
xfs_calc_growrtfree_reservation uses the current size of the realtime
summary file (m_rsumsize) to compute the transaction reservation for a
growrtfree transaction. The reservations are computed at mount time,
which means that m_rsumsize is zero when growfs starts "freeing" the new
realtime extents into the rt volume. As a result, the transaction is
undersized and fails.
Fix this by recomputing the transaction reservations every time we
change m_rsumsize.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Don't allow realtime volumes that are less than one rt extent long.
This has been broken across 4 LTS kernels with nobody noticing, so let's
just disable it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There's a weird discrepancy in xfsprogs dating back to the creation of
the Linux port -- if there are zero rt extents, mkfs will set
sb_rextents and sb_rextslog both to zero:
sbp->sb_rextslog =
(uint8_t)(rtextents ?
libxfs_highbit32((unsigned int)rtextents) : 0);
However, that's not the check that xfs_repair uses for nonzero rtblocks:
if (sb->sb_rextslog !=
libxfs_highbit32((unsigned int)sb->sb_rextents))
The difference here is that xfs_highbit32 returns -1 if its argument is
zero. Unfortunately, this means that in the weird corner case of a
realtime volume shorter than 1 rt extent, xfs_repair will immediately
flag a freshly formatted filesystem as corrupt. Because mkfs has been
writing ondisk artifacts like this for decades, we have to accept that
as "correct". TBH, zero rextslog for zero rtextents makes more sense to
me anyway.
Regrettably, the superblock verifier checks created in commit copied
xfs_repair even though mkfs has been writing out such filesystems for
ages. Fix the superblock verifier to accept what mkfs spits out; the
userspace version of this patch will have to fix xfs_repair as well.
Note that the new helper leaves the zeroday bug where the upper 32 bits
of sb_rextents is ripped off and fed to highbit32. This leads to a
seriously undersized rt summary file, which immediately breaks mkfs:
$ hugedisk.sh foo /dev/sdc $(( 0x100000080 * 4096))B
$ /sbin/mkfs.xfs -f /dev/sda -m rmapbt=0,reflink=0 -r rtdev=/dev/mapper/foo
meta-data=/dev/sda isize=512 agcount=4, agsize=1298176 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=0 bigtime=1 inobtcount=1 nrext64=1
data = bsize=4096 blocks=5192704, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =/dev/mapper/foo extsz=4096 blocks=4294967424, rtextents=4294967424
Discarding blocks...Done.
mkfs.xfs: Error initializing the realtime space [117 - Structure needs cleaning]
The next patch will drop support for rt volumes with fewer than 1 or
more than 2^32-1 rt extents, since they've clearly been broken forever.
Fixes: f8e566c0f5 ("xfs: validate the realtime geometry in xfs_validate_sb_common")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
* Realtime device subsystem
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types.
- Replace open coded conversions between rt blocks and rt extents with
calls to static inline helpers.
- Replace open coded realtime geometry compuation and macros with helper
functions.
- CPU usage optimizations for realtime allocator.
- Misc. Bug fixes associated with Realtime device.
* Allow read operations to execute while an FICLONE ioctl is being serviced.
* Misc. bug fixes
- Alert user when xfs_droplink() encounters an inode with a link count of zero.
- Handle the case where the allocator could return zero extents when
servicing an fallocate request.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
- Realtime device subsystem:
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types
- Replace open coded conversions between rt blocks and rt extents
with calls to static inline helpers
- Replace open coded realtime geometry compuation and macros with
helper functions
- CPU usage optimizations for realtime allocator
- Misc bug fixes associated with Realtime device
- Allow read operations to execute while an FICLONE ioctl is being
serviced
- Misc bug fixes:
- Alert user when xfs_droplink() encounters an inode with a link
count of zero
- Handle the case where the allocator could return zero extents when
servicing an fallocate request
* tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (40 commits)
xfs: allow read IO and FICLONE to run concurrently
xfs: handle nimaps=0 from xfs_bmapi_write in xfs_alloc_file_space
xfs: introduce protection for drop nlink
xfs: don't look for end of extent further than necessary in xfs_rtallocate_extent_near()
xfs: don't try redundant allocations in xfs_rtallocate_extent_near()
xfs: limit maxlen based on available space in xfs_rtallocate_extent_near()
xfs: return maximum free size from xfs_rtany_summary()
xfs: invert the realtime summary cache
xfs: simplify rt bitmap/summary block accessor functions
xfs: simplify xfs_rtbuf_get calling conventions
xfs: cache last bitmap block in realtime allocator
xfs: use accessor functions for summary info words
xfs: consolidate realtime allocation arguments
xfs: create helpers for rtsummary block/wordcount computations
xfs: use accessor functions for bitmap words
xfs: create helpers for rtbitmap block/wordcount computations
xfs: create a helper to handle logging parts of rt bitmap/summary blocks
xfs: convert rt summary macros to helpers
xfs: convert open-coded xfs_rtword_t pointer accesses to helper
xfs: remove XFS_BLOCKWSIZE and XFS_BLOCKWMASK macros
...
As explained in the previous commit, xfs_rtallocate_extent_near() looks
for the end of a free extent when searching backwards from the target
bitmap block. Since the previous commit, it searches from the last
bitmap block it checked to the bitmap block containing the start of the
extent.
This may still be more than necessary, since the free extent may not be
that long. We know the maximum size of the free extent from the realtime
summary. Use that to compute how many bitmap blocks we actually need to
check.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_rtallocate_extent_near() tries to find a free extent as close to a
target bitmap block given by bbno as possible, which may be before or
after bbno. Searching backwards has a complication: the realtime summary
accounts for free space _starting_ in a bitmap block, but not straddling
or ending in a bitmap block. So, when the negative search finds a free
extent in the realtime summary, in order to end up closer to the target,
it looks for the end of the free extent. For example, if bbno - 2 has a
free extent, then it will check bbno - 1, then bbno - 2. But then if
bbno - 3 has a free extent, it will check bbno - 1 again, then bbno - 2
again, and then bbno - 3. This results in a quadratic loop, which is
completely pointless since the repeated checks won't find anything new.
Fix it by remembering where we last checked up to and continue from
there. This also obviates the need for a check of the realtime summary.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_rtallocate_extent_near() calls xfs_rtallocate_extent_block() with
the minlen and maxlen that were passed to it.
xfs_rtallocate_extent_block() then scans the bitmap block looking for a
free range of size maxlen. If there is none, it has to scan the whole
bitmap block before returning the largest range of at least size minlen.
For a fragmented realtime device and a large allocation request, it's
almost certain that this will have to search the whole bitmap block,
leading to high CPU usage.
However, the realtime summary tells us the maximum size available in the
bitmap block. We can limit the search in xfs_rtallocate_extent_block()
to that size and often stop before scanning the whole bitmap block.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Instead of only returning whether there is any free space, return the
maximum size, which is fast thanks to the previous commit. This will be
used by two upcoming optimizations.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In commit 355e353213 ("xfs: cache minimum realtime summary level"), I
added a cache of the minimum level of the realtime summary that has any
free extents. However, it turns out that the _maximum_ level is more
useful for upcoming optimizations, and basically equivalent for the
existing usage. So, let's change the meaning of the cache to be the
maximum level + 1, or 0 if there are no free extents.
For example, if the cache contains:
{0, 4}
then there are no free extents starting in realtime bitmap block 0, and
there are no free extents larger than or equal to 2^4 blocks starting in
realtime bitmap block 1. The cache is a loose upper bound, so there may
or may not be free extents smaller than 2^4 blocks in realtime bitmap
block 1.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Profiling a workload on a highly fragmented realtime device showed a ton
of CPU cycles being spent in xfs_trans_read_buf() called by
xfs_rtbuf_get(). Further tracing showed that much of that was repeated
calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
These come from xfs_rtallocate_extent_block(): as it walks through
ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
is very fragmented, then this is _a lot_ of buffer lookups.
The realtime allocator already passes around a cache of the last used
realtime summary block to avoid repeated reads (the parameters rbpp and
rsb). We can do the same for the realtime bitmap.
This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
the most recently used block for both the realtime bitmap and summary.
xfs_rtbuf_get() now handles the caching instead of the callers, which
requires plumbing xfs_rtbuf_cache to more functions but also makes sure
we don't miss anything.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Consolidate the arguments passed around the rt allocator into a
struct xfs_rtalloc_arg similar to how the btree allocator arguments
are consolidated in a struct xfs_alloc_arg....
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create helper functions that compute the number of blocks or words
necessary to store the rt summary file.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create helper functions that compute the number of blocks or words
necessary to store the rt bitmap.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Replace these macros with typechecked helper functions. Eventually
we're going to add more logic to the helpers and it'll be easier if we
don't have to macro it up.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Avoid the costs of integer division (32-bit and 64-bit) if the realtime
extent size is a power of two.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Convert these calls to use the helpers, and clean up all these places
where the same variable can have different units depending on where it
is in the function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Further disambiguate the xfs_rtblock_t uses by creating a new type,
xfs_rtxnum_t, to store the position of an extent within the realtime
section, in units of rtextents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We should use xfs_fileoff_t to store the file block offset of any
location within the realtime bitmap or summary files.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In most of the filesystem, we use xfs_extlen_t to store the length of a
file (or AG) space mapping in units of fs blocks. Unfortunately, the
realtime allocator also uses it to store the length of a rt space
mapping in units of rt extents. This is confusing, since one rt extent
can consist of many fs blocks.
Separate the two by introducing a new type (xfs_rtxlen_t) to store the
length of a space mapping (in units of realtime extents) that would be
found in a file.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move all the declarations for functionality in xfs_rtbitmap.c into a
separate xfs_rtbitmap.h header file.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In commit 2a6ca4baed, we tried to fix an overflow problem in the
realtime allocator that was caused by an overly large maxlen value
causing xfs_rtcheck_range to run off the end of the realtime bitmap.
Unfortunately, there is a subtle bug here -- maxlen (and minlen) both
have to be aligned with @prod, but @prod can be larger than 1 if the
user has set an extent size hint on the file, and that extent size hint
is larger than the realtime extent size.
If the rt free space extents are not aligned to this file's extszhint
because other files without extent size hints allocated space (or the
number of rt extents is similarly not aligned), then it's possible that
maxlen after clamping to sb_rextents will no longer be aligned to prod.
The allocation will succeed just fine, but we still trip the assertion.
Fix the problem by reducing maxlen by any misalignment with prod. While
we're at it, split the assertions into two so that we can tell which
value had the bad alignment.
Fixes: 2a6ca4baed ("xfs: make sure the rt allocator doesn't run off the end")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Quotas aren't (yet) supported with realtime, so we shouldn't allow
userspace to set up a realtime section when quotas are enabled, even if
they attached one via mount options. IOWS, you shouldn't be able to do:
# mkfs.xfs -f /dev/sda
# mount /dev/sda /mnt -o rtdev=/dev/sdb,usrquota
# xfs_growfs -r /mnt
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_rtalloc_query_range scans the realtime bitmap file in order of
increasing file offset, so this caller can take ILOCK_SHARED on the rt
bitmap inode instead of ILOCK_EXCL. This isn't going to yield any
practical benefits at mount time, but we'd like to make the locking
usage consistent around xfs_rtalloc_query_all calls. Make all the
places we do this use the same xfs_ilock lockflags for consistency.
Fixes: 4c934c7dd6 ("xfs: report realtime space information via the rtbitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
It turns out that GETFSMAP and online fsck have had a bug for years due
to their use of ILOCK_SHARED to coordinate their linear scans of the
realtime bitmap. If the bitmap file's data fork happens to be in BTREE
format and the scan occurs immediately after mounting, the incore bmbt
will not be populated, leading to ASSERTs tripping over the incorrect
inode state. Because the bitmap scans always lock bitmap buffers in
increasing order of file offset, it is appropriate for these two callers
to take a shared ILOCK to improve scalability.
To fix this problem, load both data and attr fork state into memory when
mounting the realtime inodes. Realtime metadata files aren't supposed
to have an attr fork so the second step is likely a nop.
On most filesystems this is unlikely since the rtbitmap data fork is
usually in extents format, but it's possible to craft a filesystem that
will by fragmenting the free space in the data section and growfsing the
rt section.
Fixes: 4c934c7dd6 ("xfs: report realtime space information via the rtbitmap")
Also-Fixes: 46d9bfb5e7 ("xfs: cross-reference the realtime bitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
xfs: Large extent counters
The commit xfs: fix inode fork extent count overflow
(3f8a4f1d87) mentions that 10 billion
data fork extents should be possible to create. However the
corresponding on-disk field has a signed 32-bit type. Hence this
patchset extends the per-inode data fork extent counter to 64 bits
(out of which 48 bits are used to store the extent count).
Also, XFS has an attribute fork extent counter which is 16 bits
wide. A workload that,
1. Creates 1 million 255-byte sized xattrs,
2. Deletes 50% of these xattrs in an alternating manner,
3. Tries to insert 400,000 new 255-byte sized xattrs
causes the xattr extent counter to overflow.
Dave tells me that there are instances where a single file has more
than 100 million hardlinks. With parent pointers being stored in
xattrs, we will overflow the signed 16-bits wide attribute extent
counter when large number of hardlinks are created. Hence this
patchset extends the on-disk field to 32-bits.
The following changes are made to accomplish this,
1. A 64-bit inode field is carved out of existing di_pad and
di_flushiter fields to hold the 64-bit data fork extent counter.
2. The existing 32-bit inode data fork extent counter will be used to
hold the attribute fork extent counter.
3. A new incompat superblock flag to prevent older kernels from mounting
the filesystem.
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit enables upgrading existing inodes to use large extent counters
provided that underlying filesystem's superblock has large extent counter
feature enabled.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
As mentioned in the previous commit, the kernel misuses sb_frextents in
the incore mount to reflect both incore reservations made by running
transactions as well as the actual count of free rt extents on disk.
This results in the superblock being written to the log with an
underestimate of the number of rt extents that are marked free in the
rtbitmap.
Teaching XFS to recompute frextents after log recovery avoids
operational problems in the current mount, but it doesn't solve the
problem of us writing undercounted frextents which are then recovered by
an older kernel that doesn't have that fix.
Create an incore percpu counter to mirror the ondisk frextents. This
new counter will track transaction reservations and the only time we
will touch the incore super counter (i.e the one that gets logged) is
when those transactions commit updates to the rt bitmap. This is in
contrast to the lazysbcount counters (e.g. fdblocks), where we know that
log recovery will always fix any incorrect counter that we log.
As a bonus, we only take m_sb_lock at transaction commit time.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
I've been observing periodic corruption reports from xfs_scrub involving
the free rt extent counter (frextents) while running xfs/141. That test
uses an error injection knob to induce a torn write to the log, and an
arbitrary number of recovery mounts, frextents will count fewer free rt
extents than can be found the rtbitmap.
The root cause of the problem is a combination of the misuse of
sb_frextents in the incore mount to reflect both incore reservations
made by running transactions as well as the actual count of free rt
extents on disk. The following sequence can reproduce the undercount:
Thread 1 Thread 2
xfs_trans_alloc(rtextents=3)
xfs_mod_frextents(-3)
<blocks>
xfs_attr_set()
xfs_bmap_attr_addfork()
xfs_add_attr2()
xfs_log_sb()
xfs_sb_to_disk()
xfs_trans_commit()
<log flushed to disk>
<log goes down>
Note that thread 1 subtracts 3 from sb_frextents even though it never
commits to using that space. Thread 2 writes the undercounted value to
the ondisk superblock and logs it to the xattr transaction, which is
then flushed to disk. At next mount, log recovery will find the logged
superblock and write that back into the filesystem. At the end of log
recovery, we reread the superblock and install the recovered
undercounted frextents value into the incore superblock. From that
point on, we've effectively leaked thread 1's transaction reservation.
The correct fix for this is to separate the incore reservation from the
ondisk usage, but that's a matter for the next patch. Because the
kernel has been logging superblocks with undercounted frextents for a
very long time and we don't demand that sysadmins run xfs_repair after a
crash, fix the undercount by recomputing frextents after log recovery.
Gating this on log recovery is a reasonable balance (I think) between
correcting the problem and slowing down every mount attempt. Note that
xfs_repair will fix undercounted frextents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
