When we reserve a delalloc region in xfs_buffered_write_iomap_begin,
we mark the iomap as IOMAP_F_NEW so that the the write context
understands that it allocated the delalloc region.

If we then fail that buffered write, xfs_buffered_write_iomap_end()
checks for the IOMAP_F_NEW flag and if it is set, it punches out
the unused delalloc region that was allocated for the write.

The assumption this code makes is that all buffered write operations
that can allocate space are run under an exclusive lock (i_rwsem).
This is an invalid assumption: page faults in mmap()d regions call
through this same function pair to map the file range being faulted
and this runs only holding the inode->i_mapping->invalidate_lock in
shared mode.

IOWs, we can have races between page faults and write() calls that
fail the nested page cache write operation that result in data loss.
That is, the failing iomap_end call will punch out the data that
the other racing iomap iteration brought into the page cache. This
can be reproduced with generic/34[46] if we arbitrarily fail page
cache copy-in operations from write() syscalls.

Code analysis tells us that the iomap_page_mkwrite() function holds
the already instantiated and uptodate folio locked across the iomap
mapping iterations. Hence the folio cannot be removed from memory
whilst we are mapping the range it covers, and as such we do not
care if the mapping changes state underneath the iomap iteration
loop:

1. if the folio is not already dirty, there is no writeback races
   possible.
2. if we allocated the mapping (delalloc or unwritten), the folio
   cannot already be dirty. See #1.
3. If the folio is already dirty, it must be up to date. As we hold
   it locked, it cannot be reclaimed from memory. Hence we always
   have valid data in the page cache while iterating the mapping.
4. Valid data in the page cache can exist when the underlying
   mapping is DELALLOC, UNWRITTEN or WRITTEN. Having the mapping
   change from DELALLOC->UNWRITTEN or UNWRITTEN->WRITTEN does not
   change the data in the page - it only affects actions if we are
   initialising a new page. Hence #3 applies  and we don't care
   about these extent map transitions racing with
   iomap_page_mkwrite().
5. iomap_page_mkwrite() checks for page invalidation races
   (truncate, hole punch, etc) after it locks the folio. We also
   hold the mapping->invalidation_lock here, and hence the mapping
   cannot change due to extent removal operations while we are
   iterating the folio.

As such, filesystems that don't use bufferheads will never fail
the iomap_folio_mkwrite_iter() operation on the current mapping,
regardless of whether the iomap should be considered stale.

Further, the range we are asked to iterate is limited to the range
inside EOF that the folio spans. Hence, for XFS, we will only map
the exact range we are asked for, and we will only do speculative
preallocation with delalloc if we are mapping a hole at the EOF
page. The iterator will consume the entire range of the folio that
is within EOF, and anything beyond the EOF block cannot be accessed.
We never need to truncate this post-EOF speculative prealloc away in
the context of the iomap_page_mkwrite() iterator because if it
remains unused we'll remove it when the last reference to the inode
goes away.

Hence we don't actually need an .iomap_end() cleanup/error handling
path at all for iomap_page_mkwrite() for XFS. This means we can
separate the page fault processing from the complexity of the
.iomap_end() processing in the buffered write path. This also means
that the buffered write path will also be able to take the
mapping->invalidate_lock as necessary.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>

The kernel robot complained about this:

>> fs/xfs/xfs_file.c:1266:31: sparse: sparse: incorrect type in return expression (different base types) @@     expected int @@     got restricted vm_fault_t @@
   fs/xfs/xfs_file.c:1266:31: sparse:     expected int
   fs/xfs/xfs_file.c:1266:31: sparse:     got restricted vm_fault_t
   fs/xfs/xfs_file.c:1314:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted vm_fault_t [usertype] ret @@     got int @@
   fs/xfs/xfs_file.c:1314:21: sparse:     expected restricted vm_fault_t [usertype] ret
   fs/xfs/xfs_file.c:1314:21: sparse:     got int

Fix the incorrect return type for these two functions.

While we're at it, make the !fsdax version return VM_FAULT_SIGBUS
because a zero return value will cause some callers to try to lock
vmf->page, which we never set here.

Fixes: ea6c49b7 ("xfs: support CoW in fsdax mode")
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

If a blkdev_issue_flush fails, fsync needs to report that to upper
levels.  Modify xfs_file_fsync to capture the errors, while trying to
flush as much data and log updates to disk as possible.

If log writes cannot flush the data device, we need to shut down the log
immediately because we've violated a log invariant.  Modify this code to
check the return value of blkdev_issue_flush as well.

This behavior seems to go back to about 2.6.15 or so, which makes this
fixes tag a bit misleading.

Link: https://elixir.bootlin.com/linux/v2.6.15/source/fs/xfs/xfs_vnodeops.c#L1187
Fixes: b5071ada ("xfs: remove xfs_blkdev_issue_flush")
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

This adds the async buffered write support to XFS. For async buffered
write requests, the request will return -EAGAIN if the ilock cannot be
obtained immediately.
Signed-off-by: NStefan Roesch <shr@fb.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-15-shr@fb.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files who
are going to be deduped.  After that, call compare range function only
when files are both DAX or not.

Link: https://lkml.kernel.org/r/20220603053738.1218681-15-ruansy.fnst@fujitsu.comSigned-off-by: NShiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

In fsdax mode, WRITE and ZERO on a shared extent need CoW performed. 
After that, new allocated extents needs to be remapped to the file.  So,
add a CoW identification in ->iomap_begin(), and implement ->iomap_end()
to do the remapping work.

[akpm@linux-foundation.org: make xfs_dax_fault() static]
Link: https://lkml.kernel.org/r/20220603053738.1218681-14-ruansy.fnst@fujitsu.comSigned-off-by: NShiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Retry unaligned DIO with exclusive blocking semantics only when the
IOCB_NOWAIT flag is not set. If we are doing nonblocking user I/O,
propagate the error directly.
Signed-off-by: NKaixu Xia <kaixuxia@tencent.com>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Allow the file system to keep state for all iterations.  For now only
wire it up for direct I/O as there is an immediate need for it there.
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChandan Babu R <chandan.babu@oracle.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Get the struct inode pointer from iocb->ki_filp->f_mapping->host
directly and the other variables are unnecessary, so simplify the
local variables assignment.
Signed-off-by: NKaixu Xia <kaixuxia@tencent.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Remove the open-coded check of O_LARGEFILE.  This changes the errno
to be the same as other filesystems; it was changed generically in
2.6.24 but that fix skipped XFS.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Since we've started treating fallocate more like a file write, we
should flush the log to disk if the user has asked for synchronous
writes either by setting it via fcntl flags, or inode flags, or with
the sync mount option.  We've already got a helper for this, so use
it.

[The original patch by Darrick was massaged by Dave to fit this patchset]
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>

The operations that xfs_update_prealloc_flags() perform are now
unique to xfs_fs_map_blocks(), so move xfs_update_prealloc_flags()
to be a static function in xfs_pnfs.c and cut out all the
other functionality that is doesn't use anymore.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

Now that we only call xfs_update_prealloc_flags() from
xfs_file_fallocate() in the case where we need to set the
preallocation flag, do this in xfs_alloc_file_space() where we
already have the inode joined into a transaction and get
rid of the call to xfs_update_prealloc_flags() from the fallocate
code.

This also means that we now correctly avoid setting the
XFS_DIFLAG_PREALLOC flag when xfs_is_always_cow_inode() is true, as
these inodes will never have preallocated extents.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In XFS, we always update the inode change and modification time when
any fallocate() operation succeeds.  Furthermore, as various
fallocate modes can change the file contents (extending EOF,
punching holes, zeroing things, shifting extents), we should drop
file privileges like suid just like we do for a regular write().
There's already a VFS helper that figures all this out for us, so
use that.

The net effect of this is that we no longer drop suid/sgid if the
caller is root, but we also now drop file capabilities.

We also move the xfs_update_prealloc_flags() function so that it now
is only called by the scope that needs to set the the prealloc flag.

Based on a patch from Darrick Wong.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

Callers can acheive the same thing by calling xfs_log_force_inode()
after making their modifications. There is no need for
xfs_update_prealloc_flags() to do this.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

According to the glibc compat header for Irix 4, these ioctls originated
in April 1991 as a (somewhat clunky) way to preallocate space at the end
of a file on an EFS filesystem.  XFS, which was released in Irix 5.3 in
December 1993, picked up these ioctls to maintain compatibility and they
were ported to Linux in the early 2000s.

Recently it was pointed out to me they still lurk in the kernel, even
though the Linux fallocate syscall supplanted the functionality a long
time ago.  fstests doesn't seem to include any real functional or stress
tests for these ioctls, which means that the code quality is ... very
questionable.  Most notably, it was a stale disk block exposure vector
for 21 years and nobody noticed or complained.  As mature programmers
say, "If you're not testing it, it's broken."

Given all that, let's withdraw these ioctls from the XFS userspace API.
Normally we'd set a long deprecation process, but I estimate that there
aren't any real users, so let's trigger a warning in dmesg and return
-ENOTTY.

See: CVE-2021-4155

Augments: 983d8e60 ("xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate")
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Add helpers to prepare for using different DAX operations.
Signed-off-by: NShiyang Ruan <ruansy.fnst@fujitsu.com>
[hch: split from a larger patch + slight cleanups]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-16-hch@lst.deSigned-off-by: NDan Williams <dan.j.williams@intel.com>

Add a done_before argument to iomap_dio_rw that indicates how much of
the request has already been transferred.  When the request succeeds, we
report that done_before additional bytes were tranferred.  This is
useful for finishing a request asynchronously when part of the request
has already been completed synchronously.

We'll use that to allow iomap_dio_rw to be used with page faults
disabled: when a page fault occurs while submitting a request, we
synchronously complete the part of the request that has already been
submitted.  The caller can then take care of the page fault and call
iomap_dio_rw again for the rest of the request, passing in the number of
bytes already tranferred.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

 - the cookie construction can made entirely private in blk-mq.c
 - the caller does not need to remember the request_queue and cookie
   separately and thus sidesteps their lifetime issues
 - keeping the device and the cookie inside the bio allows to trivially
   support polling BIOs remapping by stacking drivers
 - a lot of code to propagate the cookie back up the submission path can
   be removed entirely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NMark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Remove the shouty macro and instead use the inline function that
matches other state/feature check wrapper naming. This conversion
was done with sed.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

Replace m_flags feature checks with xfs_has_<feature>() calls and
rework the setup code to set flags in m_features.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

Convert the xfs_sb_version_hasfoo() to checks against
mp->m_features. Checks of the superblock itself during disk
operations (e.g. in the read/write verifiers and the to/from disk
formatters) are not converted - they operate purely on the
superblock state. Everything else should use the mount features.

Large parts of this conversion were done with sed with commands like
this:

for f in `git grep -l xfs_sb_version_has fs/xfs/*.c`; do
	sed -i -e 's/xfs_sb_version_has\(.*\)(&\(.*\)->m_sb)/xfs_has_\1(\2)/' $f
done

With manual cleanups for things like "xfs_has_extflgbit" and other
little inconsistencies in naming.

The result is ia lot less typing to check features and an XFS binary
size reduced by a bit over 3kB:

$ size -t fs/xfs/built-in.a
	text	   data	    bss	    dec	    hex	filenam
before	1130866  311352     484 1442702  16038e (TOTALS)
after	1127727  311352     484 1439563  15f74b (TOTALS)
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

Use invalidate_lock instead of XFS internal i_mmap_lock. The intended
purpose of invalidate_lock is exactly the same. Note that the locking in
__xfs_filemap_fault() slightly changes as filemap_fault() already takes
invalidate_lock.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
CC: <linux-xfs@vger.kernel.org>
CC: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: NJan Kara <jack@suse.cz>

In doing an investigation into AIL push stalls, I was looking at the
log force code to see if an async CIL push could be done instead.
This lead me to xfs_log_force_lsn() and looking at how it works.

xfs_log_force_lsn() is only called from inode synchronisation
contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn
value as the LSN to sync the log to. This gets passed to
xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the
journal, and then used by xfs_log_force_lsn() to flush the iclogs to
the journal.

The problem is that ip->i_itemp->ili_last_lsn does not store a
log sequence number. What it stores is passed to it from the
->iop_committing method, which is called by xfs_log_commit_cil().
The value this passes to the iop_committing method is the CIL
context sequence number that the item was committed to.

As it turns out, xlog_cil_force_lsn() converts the sequence to an
actual commit LSN for the related context and returns that to
xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn"
variable that contained a sequence with an actual LSN and then uses
that to sync the iclogs.

This caused me some confusion for a while, even though I originally
wrote all this code a decade ago. ->iop_committing is only used by
a couple of log item types, and only inode items use the sequence
number it is passed.

Let's clean up the API, CIL structures and inode log item to call it
a sequence number, and make it clear that the high level code is
using CIL sequence numbers and not on-disk LSNs for integrity
synchronisation purposes.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

It's a one line wrapper around blkdev_issue_flush(). Just replace it
with direct calls to blkdev_issue_flush().
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

The xfs_eofblocks structure is no longer well-named -- nowadays it
provides optional filtering criteria to any walk of the incore inode
cache.  Only one of the cache walk goals has anything to do with
clearing of speculative post-EOF preallocations, so change the name to
be more appropriate.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

In preparation for renaming struct xfs_eofblocks to struct xfs_icwalk,
change the prefix of the existing XFS_EOF_FLAGS_* flags to
XFS_ICWALK_FLAG_ and convert all the existing users.  This adds a degree
of interface separation between the ioctl definitions and the incore
parameters.  Since FLAGS_UNION is only used in xfs_icache.c, move it
there as a private flag.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>

Because this happens at high thread counts on high IOPS devices
doing mixed read/write AIO-DIO to a single file at about a million
iops:

   64.09%     0.21%  [kernel]            [k] io_submit_one
   - 63.87% io_submit_one
      - 44.33% aio_write
         - 42.70% xfs_file_write_iter
            - 41.32% xfs_file_dio_write_aligned
               - 25.51% xfs_file_write_checks
                  - 21.60% _raw_spin_lock
                     - 21.59% do_raw_spin_lock
                        - 19.70% __pv_queued_spin_lock_slowpath

This also happens of the IO completion IO path:

   22.89%     0.69%  [kernel]            [k] xfs_dio_write_end_io
   - 22.49% xfs_dio_write_end_io
      - 21.79% _raw_spin_lock
         - 20.97% do_raw_spin_lock
            - 20.10% __pv_queued_spin_lock_slowpath

IOWs, fio is burning ~14 whole CPUs on this spin lock.

So, do an unlocked check against inode size first, then if we are
at/beyond EOF, take the spinlock and recheck. This makes the
spinlock disappear from the overwrite fastpath.

I'd like to report that fixing this makes things go faster. It
doesn't - it just exposes the the XFS_ILOCK as the next severe
contention point doing extent mapping lookups, and that now burns
all the 14 CPUs this spinlock was burning.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fall through */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:

fs/xfs/libxfs/xfs_alloc.c:3167:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_da_btree.c:286:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:346:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:388:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_bmap_util.c:246:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:88:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:96:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_file.c:867:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:562:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:1548:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_iomap.c:1040:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_inode.c:852:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_log.c:2627:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_trans_buf.c:298:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/bmap.c:275:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/btree.c:48:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:85:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:138:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:698:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/dabtree.c:51:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/repair.c:951:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/agheader.c:89:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

In preparation of removing the historic icinode struct, move the flags2
field into the containing xfs_inode structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In preparation of removing the historic icinode struct, move the flags
field into the containing xfs_inode structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In preparation of removing the historic icinode struct, move the
cowextsize field into the containing xfs_inode structure.  Also
switch to use the xfs_extlen_t instead of a uint32_t.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In preparation of removing the historic icinode struct, move the on-disk
size field into the containing xfs_inode structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

In anticipation of more restructuring of the eof/cowblocks gc code,
refactor calling of those two functions into a single internal helper
function, then present a new standard interface to purge speculative
block preallocations and start shifting higher level code to use that.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

Change the signature of xfs_blockgc_free_quota in preparation for the
next few patches.  Callers can now pass EOF_FLAGS into the function to
control scan parameters; and the function will now pass back any
corruption errors seen while scanning, though for our retry loops we'll
just try again unconditionally.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

Move this function further down in the file so that later cleanups won't
have to declare static functions.  Change the name because we're about
to rework all the code that performs garbage collection of speculatively
allocated file blocks.  No functional changes.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

The functions to run an eof/cowblocks scan to try to reduce quota usage
are kind of a mess -- the logic repeatedly initializes an eofb structure
and there are logic bugs in the code that result in the cowblocks scan
never actually happening.

Replace all three functions with a single function that fills out an
eofb and runs both eof and cowblocks scans.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

Attempt shared locking for unaligned DIO, but only if the the
underlying extent is already allocated and in written state. On
failure, retry with the existing exclusive locking.

Test case is fio randrw of 512 byte IOs using AIO and an iodepth of
32 IOs.

Vanilla:

  READ: bw=4560KiB/s (4670kB/s), 4560KiB/s-4560KiB/s (4670kB/s-4670kB/s), io=134MiB (140MB), run=30001-30001msec
  WRITE: bw=4567KiB/s (4676kB/s), 4567KiB/s-4567KiB/s (4676kB/s-4676kB/s), io=134MiB (140MB), run=30001-30001msec

Patched:
   READ: bw=37.6MiB/s (39.4MB/s), 37.6MiB/s-37.6MiB/s (39.4MB/s-39.4MB/s), io=1127MiB (1182MB), run=30002-30002msec
  WRITE: bw=37.6MiB/s (39.4MB/s), 37.6MiB/s-37.6MiB/s (39.4MB/s-39.4MB/s), io=1128MiB (1183MB), run=30002-30002msec

That's an improvement from ~18k IOPS to a ~150k IOPS, which is
about the IOPS limit of the VM block device setup I'm testing on.

4kB block IO comparison:

   READ: bw=296MiB/s (310MB/s), 296MiB/s-296MiB/s (310MB/s-310MB/s), io=8868MiB (9299MB), run=30002-30002msec
  WRITE: bw=296MiB/s (310MB/s), 296MiB/s-296MiB/s (310MB/s-310MB/s), io=8878MiB (9309MB), run=30002-30002msec

Which is ~150k IOPS, same as what the test gets for sub-block
AIO+DIO writes with this patch.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
[hch: rebased, split unaligned from nowait]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>

The unaligned DIO write path is more convolted than the normal path,
and we are about to make it more complex. Keep the block aligned
fast path dio write code trim and simple by splitting out the
unaligned DIO code from it.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
[hch: rebased, fixed a few minor nits]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>