xfs: pass perag to xfs_alloc_read_agf()

xfs_alloc_read_agf() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. Th

xfs: pass perag to xfs_alloc_read_agf()

xfs_alloc_read_agf() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. This allows callers to be per-ag centric
rather than passing mount/agno pairs everywhere.

Whilst modifying the xfs_reflink_find_shared() function definition,
declare it static and remove the extern declaration as it is an
internal function only these days.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

show more ...

xfs: convert xfs_sb_version_has checks to use mount features

This is a conversion of the remaining xfs_sb_version_has..(sbp)
checks to use xfs_has_..(mp) feature checks.

This was largely done with

xfs: convert xfs_sb_version_has checks to use mount features

This is a conversion of the remaining xfs_sb_version_has..(sbp)
checks to use xfs_has_..(mp) feature checks.

This was largely done with a vim replacement macro that did:

:0,$s/xfs_sb_version_has\(.*\)&\(.*\)->m_sb/xfs_has_\1\2/g<CR>

A couple of other variants were also used, and the rest touched up
by hand.

$ size -t fs/xfs/built-in.a
text data bss dec hex filename
before 1127533 311352 484 1439369 15f689 (TOTALS)
after 1125360 311352 484 1437196 15ee0c (TOTALS)

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>

show more ...

xfs: move helpers that lock and unlock two inodes against userspace IO

Move the double-inode locking helpers to xfs_inode.c since they're not
specific to reflink.

Signed-off-by: Darrick J. Wong <da

xfs: move helpers that lock and unlock two inodes against userspace IO

Move the double-inode locking helpers to xfs_inode.c since they're not
specific to reflink.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

show more ...

xfs: refactor locking and unlocking two inodes against userspace IO

Refactor the two functions that we use to lock and unlock two inodes to
block userspace from initiating IO against a file, whether

xfs: refactor locking and unlocking two inodes against userspace IO

Refactor the two functions that we use to lock and unlock two inodes to
block userspace from initiating IO against a file, whether via system
calls or mmap activity.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

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xfs: change return value of xfs_inode_need_cow to int

Fixes coccicheck warning:

fs/xfs/xfs_reflink.c:236:9-10: WARNING: return of 0/1 in function 'xfs_inode_need_cow' with return type bool

Reporte

xfs: change return value of xfs_inode_need_cow to int

Fixes coccicheck warning:

fs/xfs/xfs_reflink.c:236:9-10: WARNING: return of 0/1 in function 'xfs_inode_need_cow' with return type bool

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
[darrick: rename the function so it doesn't sound like a predicate]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: pass two imaps to xfs_reflink_allocate_cow

xfs_reflink_allocate_cow consumes the source data fork imap, and
potentially returns the COW fork imap. Split the arguments in two
to clear up the ca

xfs: pass two imaps to xfs_reflink_allocate_cow

xfs_reflink_allocate_cow consumes the source data fork imap, and
potentially returns the COW fork imap. Split the arguments in two
to clear up the calling conventions and to prepare for returning
a source iomap from ->iomap_begin.

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>

show more ...

xfs: don't pass iomap flags to xfs_reflink_allocate_cow

Don't pass raw iomap flags to xfs_reflink_allocate_cow; signal our
intention with a boolean argument.

Signed-off-by: Darrick J. Wong <darrick

xfs: don't pass iomap flags to xfs_reflink_allocate_cow

Don't pass raw iomap flags to xfs_reflink_allocate_cow; signal our
intention with a boolean argument.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

show more ...

xfs: introduce an always_cow mode

Add a mode where XFS never overwrites existing blocks in place. This
is to aid debugging our COW code, and also put infatructure in place
for things like possible

xfs: introduce an always_cow mode

Add a mode where XFS never overwrites existing blocks in place. This
is to aid debugging our COW code, and also put infatructure in place
for things like possible future support for zoned block devices, which
can't support overwrites.

This mode is enabled globally by doing a:

echo 1 > /sys/fs/xfs/debug/always_cow

Note that the parameter is global to allow running all tests in xfstests
easily in this mode, which would not easily be possible with a per-fs
sysfs file.

In always_cow mode persistent preallocations are disabled, and fallocate
will fail when called with a 0 mode (with our without
FALLOC_FL_KEEP_SIZE), and not create unwritten extent for zeroed space
when called with FALLOC_FL_ZERO_RANGE or FALLOC_FL_UNSHARE_RANGE.

There are a few interesting xfstests failures when run in always_cow
mode:

- generic/392 fails because the bytes used in the file used to test
hole punch recovery are less after the log replay. This is
because the blocks written and then punched out are only freed
with a delay due to the logging mechanism.
- xfs/170 will fail as the already fragile file streams mechanism
doesn't seem to interact well with the COW allocator
- xfs/180 xfs/182 xfs/192 xfs/198 xfs/204 and xfs/208 will claim
the file system is badly fragmented, but there is not much we
can do to avoid that when always writing out of place
- xfs/205 fails because overwriting a file in always_cow mode
will require new space allocation and the assumption in the
test thus don't work anymore.
- xfs/326 fails to modify the file at all in always_cow mode after
injecting the refcount error, leading to an unexpected md5sum
after the remount, but that again is expected

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>

show more ...

xfs: merge COW handling into xfs_file_iomap_begin_delay

Besides simplifying the code a bit this allows to actually implement
the behavior of using COW preallocation for non-COW data mentioned
in the

xfs: merge COW handling into xfs_file_iomap_begin_delay

Besides simplifying the code a bit this allows to actually implement
the behavior of using COW preallocation for non-COW data mentioned
in the current comments.

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>

show more ...

xfs: don't use delalloc extents for COW on files with extsize hints

While using delalloc for extsize hints is generally a good idea, the
current code that does so only for COW doesn't help us much a

xfs: don't use delalloc extents for COW on files with extsize hints

While using delalloc for extsize hints is generally a good idea, the
current code that does so only for COW doesn't help us much and creates
a lot of special cases. Switch it to use real allocations like we
do for direct I/O.

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>

show more ...

xfs: remove xfs_reflink_remap_range

Since xfs_file_remap_range is a thin wrapper, move the contents of
xfs_reflink_remap_range into the shell. This cuts down on the vfs
calls being made from intern

xfs: remove xfs_reflink_remap_range

Since xfs_file_remap_range is a thin wrapper, move the contents of
xfs_reflink_remap_range into the shell. This cuts down on the vfs
calls being made from internal xfs code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

xfs: support returning partial reflink results

Back when the XFS reflink code only supported clone_file_range, we were
only able to return zero or negative error codes to userspace. However,
now th

xfs: support returning partial reflink results

Back when the XFS reflink code only supported clone_file_range, we were
only able to return zero or negative error codes to userspace. However,
now that copy_file_range (which returns bytes copied) can use XFS'
clone_file_range, we have the opportunity to return partial results.
For example, if userspace sends a 1GB clone request and we run out of
space halfway through, we at least can tell userspace that we completed
512M of that request like a regular write.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

vfs: make remap_file_range functions take and return bytes completed

Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on.

vfs: make remap_file_range functions take and return bytes completed

Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on. This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value. For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

vfs: pass remap flags to generic_remap_file_range_prep

Plumb the remap flags through the filesystem from the vfs function
dispatcher all the way to the prep function to prepare for behavior
changes

vfs: pass remap flags to generic_remap_file_range_prep

Plumb the remap flags through the filesystem from the vfs function
dispatcher all the way to the prep function to prepare for behavior
changes in subsequent patches.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

xfs: remove the unused trimmed argument from xfs_reflink_trim_around_shared

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <

xfs: remove the unused trimmed argument from xfs_reflink_trim_around_shared

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

xfs: remove the unused shared argument to xfs_reflink_reserve_cow

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@from

xfs: remove the unused shared argument to xfs_reflink_reserve_cow

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...

xfs: remove xfs_reflink_find_cow_mapping

We only have one caller left, and open coding the simple extent list
lookup in it allows us to make the code both more understandable and
reuse calculations

xfs: remove xfs_reflink_find_cow_mapping

We only have one caller left, and open coding the simple extent list
lookup in it allows us to make the code both more understandable and
reuse calculations and variables already present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-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>

show more ...

xfs: remove xfs_reflink_trim_irec_to_next_cow

We already have to check for overlapping COW extents everytime we
come back to a page in xfs_writepage_map / xfs_map_cow, so this
additional trim is not

xfs: remove xfs_reflink_trim_irec_to_next_cow

We already have to check for overlapping COW extents everytime we
come back to a page in xfs_writepage_map / xfs_map_cow, so this
additional trim is not required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-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>

show more ...

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}

/^ \* This program is free software/ {
hdr = 2.0;
next
}

/any later version./ {
tag = "GPL-2.0+"
next
}

/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}

/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}

/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}

// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}

END { }
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

show more ...

xfs: separate function to check if inode shares extents

Separate the "clear reflink flag" function into one function that checks
if the flag is needed, and a second function that checks and clears t

xfs: separate function to check if inode shares extents

Separate the "clear reflink flag" function into one function that checks
if the flag is needed, and a second function that checks and clears the
flag. The inode scrub code will want to check the necessity of the flag
without clearing it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

show more ...

xfs: reflink find shared should take a transaction

Adapt _reflink_find_shared to take an optional transaction pointer. The
inode scrubber code will need to decide (within transaction context) if
a

xfs: reflink find shared should take a transaction

Adapt _reflink_find_shared to take an optional transaction pointer. The
inode scrubber code will need to decide (within transaction context) if
a file has shared blocks. To avoid buffer deadlocks, we must pass the
tp through to this function's utility calls.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

show more ...

xfs: only reclaim unwritten COW extents periodically

We only want to reclaim preallocations from our periodic work item.
Currently this is archived by looking for a dirty inode, but that check
is ra

xfs: only reclaim unwritten COW extents periodically

We only want to reclaim preallocations from our periodic work item.
Currently this is archived by looking for a dirty inode, but that check
is rather fragile. Instead add a flag to xfs_reflink_cancel_cow_* so
that the caller can ask for just cancelling unwritten extents in the COW
fork.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix typos in commit message]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

show more ...

xfs: allocate direct I/O COW blocks in iomap_begin

Instead of preallocating all the required COW blocks in the high-level
write code do it inside the iomap code, like we do for all other I/O.

Signe

xfs: allocate direct I/O COW blocks in iomap_begin

Instead of preallocating all the required COW blocks in the high-level
write code do it inside the iomap code, like we do for all other I/O.

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>

show more ...

xfs: mark speculative prealloc CoW fork extents unwritten

Christoph Hellwig pointed out that there's a potentially nasty race when
performing simultaneous nearby directio cow writes:

"Thread 1 writ

xfs: mark speculative prealloc CoW fork extents unwritten

Christoph Hellwig pointed out that there's a potentially nasty race when
performing simultaneous nearby directio cow writes:

"Thread 1 writes a range from B to c

" B --------- C
p

"a little later thread 2 writes from A to B

" A --------- B
p

[editor's note: the 'p' denote cowextsize boundaries, which I added to
make this more clear]

"but the code preallocates beyond B into the range where thread
"1 has just written, but ->end_io hasn't been called yet.
"But once ->end_io is called thread 2 has already allocated
"up to the extent size hint into the write range of thread 1,
"so the end_io handler will splice the unintialized blocks from
"that preallocation back into the file right after B."

We can avoid this race by ensuring that thread 1 cannot accidentally
remap the blocks that thread 2 allocated (as part of speculative
preallocation) as part of t2's write preparation in t1's end_io handler.
The way we make this happen is by taking advantage of the unwritten
extent flag as an intermediate step.

Recall that when we begin the process of writing data to shared blocks,
we create a delayed allocation extent in the CoW fork:

D: --RRRRRRSSSRRRRRRRR---
C: ------DDDDDDD---------

When a thread prepares to CoW some dirty data out to disk, it will now
convert the delalloc reservation into an /unwritten/ allocated extent in
the cow fork. The da conversion code tries to opportunistically
allocate as much of a (speculatively prealloc'd) extent as possible, so
we may end up allocating a larger extent than we're actually writing
out:

D: --RRRRRRSSSRRRRRRRR---
U: ------UUUUUUU---------

Next, we convert only the part of the extent that we're actively
planning to write to normal (i.e. not unwritten) status:

D: --RRRRRRSSSRRRRRRRR---
U: ------UURRUUU---------

If the write succeeds, the end_cow function will now scan the relevant
range of the CoW fork for real extents and remap only the real extents
into the data fork:

D: --RRRRRRRRSRRRRRRRR---
U: ------UU--UUU---------

This ensures that we never obliterate valid data fork extents with
unwritten blocks from the CoW fork.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

show more ...

xfs: use new extent lookup helpers in xfs_reflink_trim_irec_to_next_cow

And remove the unused return value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.c

xfs: use new extent lookup helpers in xfs_reflink_trim_irec_to_next_cow

And remove the unused return value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

show more ...