xfs_bmap_set_attrforkoff is only used inside of xfs_bmap.c, so mark it
static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
xfs_bmap_one_block is only called for the attribute fork. Move it to
xfs_attr.c, drop the unused whichfork argument and code only executed for
the data fork and rename the result to xfs_attr_is_leaf.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Default attr fork offset is based on inode size, so is a fixed
geometry parameter of the inode. Move it to the xfs_ino_geometry
structure and stop calculating it on every call to
xfs_default_attroffset().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Make sure that we actually initialize xefi_discard when we're scheduling
a deferred free of an AGFL block. This was (eventually) found by the
UBSAN while I was banging on realtime rmap problems, but it exists in
the upstream codebase. While we're at it, rearrange the structure to
reduce the struct size from 64 to 56 bytes.
Fixes: fcb762f5de ("xfs: add bmapi nodiscard flag")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The existing reflink remapping loop has some structural problems that
need addressing:
The biggest problem is that we create one transaction for each extent in
the source file without accounting for the number of mappings there are
for the same range in the destination file. In other words, we don't
know the number of remap operations that will be necessary and we
therefore cannot guess the block reservation required. On highly
fragmented filesystems (e.g. ones with active dedupe) we guess wrong,
run out of block reservation, and fail.
The second problem is that we don't actually use the bmap intents to
their full potential -- instead of calling bunmapi directly and having
to deal with its backwards operation, we could call the deferred ops
xfs_bmap_unmap_extent and xfs_refcount_decrease_extent instead. This
makes the frontend loop much simpler.
Solve all of these problems by refactoring the remapping loops so that
we only perform one remapping operation per transaction, and each
operation only tries to remap a single extent from source to dest.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reported-by: Edwin Török <edwin@etorok.net>
Tested-by: Edwin Török <edwin@etorok.net>
The name of this predicate is a little misleading -- it decides if the
extent mapping is allocated and written. Change the name to be more
direct, as we're going to add a new predicate in the next patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This patch corrects the SPDX License Identifier style in header files
related to XFS File System support. For C header files
Documentation/process/license-rules.rst mandates C-like comments.
(opposed to C source files where C++ style should be used).
Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The insert range operation currently splits the extent at the target
offset in a separate transaction and lock cycle from the one that
shifts extents. In preparation for reworking insert range into an
atomic operation, lift the code into the caller so it can be easily
condensed to a single rolling transaction and lock cycle and
eliminate the helper. No functional changes.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.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>
In preparation for moving the XFS writeback code to fs/iomap.c, switch
it to use struct iomap instead of the XFS-specific struct xfs_bmbt_irec.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-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>
The callers of xfs_bmap_local_to_extents_empty() log the inode
external to the function, yet this function is where the on-disk
format value is updated. Push the inode logging down into the
function itself to help prevent future mistakes.
Note that internal bmap callers track the inode logging flags
independently and thus may log the inode core twice due to this
change. This is harmless, so leave this code around for consistency
with the other attr fork conversion functions.
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>
Add a helper that validates the startblock is valid. This checks for a
non-zero block on the main device, but skips that check for blocks on
the realtime device.
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>
Remove the return value from the functions that schedule deferred bmap
operations since they never fail and do not return status.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If we have racing buffered and direct I/O COW fork extents under
writeback can have been moved to the data fork by the time we call
xfs_reflink_convert_cow from xfs_submit_ioend. This would be mostly
harmless as the block numbers don't change by this move, except for
the fact that xfs_bmapi_write will crash or trigger asserts when
not finding existing extents, even despite trying to paper over this
with the XFS_BMAPI_CONVERT_ONLY flag.
Instead of special casing non-transaction conversions in the already
way too complicated xfs_bmapi_write just add a new helper for the much
simpler non-transactional COW fork case, which simplify ignores not
found extents.
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>
No need to deal with the transaction and the inode locking in the
caller. Note that we also switch to passing whichfork as the second
paramter, matching what most related functions do.
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>
Delalloc conversion has traditionally been part of our function to
allocate blocks on disk (first xfs_bmapi, then xfs_bmapi_write), but
delalloc conversion is a little special as we really do not want
to allocate blocks over holes, for which we don't have reservations.
Split the delalloc conversions into a separate helper to keep the
code simple and structured.
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 writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping outside of the current
page. This is because the ilock is cycled between the time the
caller originally looked up the mapping and across each real
allocation of the provided file range. This code has collected
various hacks over the years to help combat the symptoms of these
races (i.e., truncate race detection, allocation into hole
detection, etc.), but none address the fundamental problem that the
imap may not be valid at allocation time.
Rather than continue to use race detection hacks, update writeback
delalloc conversion to a model that explicitly converts the delalloc
extent backing the current file offset being processed. The current
file offset is the only block we can trust to remain once the ilock
is dropped because any operation that can remove the block
(truncate, hole punch, etc.) must flush and discard pagecache pages
first.
Modify xfs_iomap_write_allocate() to use the xfs_bmapi_delalloc()
mechanism to request allocation of the entire delalloc extent
backing the current offset instead of assuming the extent passed by
the caller is unchanged. Record the range specified by the caller
and apply it to the resulting allocated extent so previous checks by
the caller for COW fork overlap are not lost. Finally, overload the
bmapi delalloc flag with the range reval flag behavior since this is
the only use case for both.
This ensures that writeback always picks up the correct
and current extent associated with the page, regardless of races
with other extent modifying operations. If operating on a data fork
and the COW overlap state has changed since the ilock was cycled,
the caller revalidates against the COW fork sequence number before
using the imap for the next block.
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>
The writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping. This stems from the
fact that the bmapi allocation code requires a file range to
allocate and the writeback conversion code assumes the range of the
currently cached mapping is still valid with respect to the fork. It
may not be valid, however, because the ilock is cycled (potentially
multiple times) between the time the cached mapping was populated
and the delalloc conversion occurs.
To facilitate a solution to this problem, create a new
xfs_bmapi_delalloc() wrapper to xfs_bmapi_write() that takes a file
(FSB) offset and attempts to allocate whatever delalloc extent backs
the offset. Use a new bmapi flag to cause xfs_bmapi_write() to set
the range based on the extent backing the bno parameter unless bno
lands in a hole. If bno does land in a hole, fall back to the
current behavior (which may result in an error or quietly skipping
holes in the specified range depending on other parameters). This
patch does not change behavior.
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>
Now that the cached writeback mapping is explicitly invalidated on
data fork changes, the EOF trimming band-aid is no longer necessary.
Remove xfs_trim_extent_eof() as well since it has no other users.
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>
Only certain functions actually change the contents of an
xfs_owner_info; the rest can accept a const struct pointer. This will
enable us to save stack space by hoisting static owner info types to
be const global variables.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This patch adds xfs_attr_set_args and xfs_bmap_set_attrforkoff.
These sub-routines set the attributes specified in @args.
We will use this later for setting parent pointers as a deferred
attribute operation.
[dgc: remove attr fork init code from xfs_attr_set_args().]
[dgc: xfs_attr_try_sf_addname() NULLs args.trans after commit.]
[dgc: correct sf add error handling.]
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
The majority of remaining references to struct xfs_defer_ops in XFS
are associated with xfs_defer_add(). At this point, there are no
more external xfs_defer_ops users left. All instances of
xfs_defer_ops are embedded in the transaction, which means we can
safely pass the transaction down to the dfops add interface.
Update xfs_defer_add() to receive the transaction as a parameter.
Various subsystems implement wrappers to allocate and construct the
context specific data structures for the associated deferred
operation type. Update these to also carry the transaction down as
needed and clean up unused dfops parameters along the way.
This removes most of the remaining references to struct
xfs_defer_ops throughout the code and facilitates removal of the
structure.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[darrick: fix unused variable warnings with ftrace disabled]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The dfops infrastructure ->finish_item() callback passes the
transaction and dfops as separate parameters. Since dfops is always
part of a transaction, the latter parameter is no longer necessary.
Remove it from the various callbacks.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The xfs_bmalloca.firstblock field carries the firstblock value from
the transaction into the bmap infrastructure. It's initialized in
one place from ->t_firstblock, so drop the field and access
->t_firstblock directly throughout the bmap code.
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>
The only callers pass ->t_firstblock.
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>
All callers pass ->t_firstblock from the current transaction.
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>
All callers pass ->t_firstblock from the current transaction.
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>
Use ->t_dfops for the collapse and insert range transactions. These
are the only callers of the respective bmap helpers, so replace the
unnecessary dfops parameters with direct accesses to ->t_dfops.
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>
Now that bma.dfops is only assigned from ->t_dfops, replace all
accesses to the former with the latter and remove the unnecessary
field. This patch does not change behavior.
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>
All xfs_bmapi_remap() callers already use ->t_dfops. Note that
deferred completion context unconditionally sets ->t_dfops if it
hasn't already been set by the caller. Remove the unnecessary
parameter and access ->t_dfops directly.
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>
Now that all xfs_bunmapi() callers use ->t_dfops, remove the
unnecessary parameter and access ->t_dfops directly. This patch does
not change behavior.
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>
Now that all callers use ->t_dfops, the xfs_bmapi_write() dfops
parameter is no longer necessary. Remove it and access ->t_dfops
directly. This patch does not change behavior.
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>
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>
Zorro Lang reports that generic/485 blows an assert on a filesystem with
512 byte blocks. The test tries to fallocate a post-eof extent at the
maximum file size and calls insert range to shift the extents right by
two blocks. On a 512b block filesystem this causes startoff to overflow
the 54-bit startoff field, leading to the assert.
Therefore, always check the rightmost extent to see if it would overflow
prior to invoking the insert range machinery.
Reported-by: zlang@redhat.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200137
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
Add a new flags argument to xfs_bmapi_remapi so that we can pass BMAPI
flags into the function. This enables us to pass in BMAPI_ATTRFORK so
that we can remap things into the attribute fork. Eventually the
online repair code will use this to rebuild attribute forks, so make it
non-static.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The changes to skip discards of speculative preallocation and
unwritten extents introduced several new wrapper functions through
the bunmapi -> extent free codepath to reduce churn in all of the
associated callers. In several cases, these wrappers simply toggle a
single flag to skip or not skip discards for the resulting blocks.
The explicit _nodiscard() wrappers for such an isolated set of
callers is a bit overkill. Kill off these wrappers and replace with
the calls to the underlying functions in the contexts that need to
control discard behavior. Retain the wrappers that preserve the
original calling conventions to serve the original purpose of
reducing code churn.
This is a refactoring patch and does not change behavior.
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>
Add a new flag, XFS_BMAPI_NORMAP, which will perform file block
remapping without updating the rmapbt. This will be used by the repair
code to reconstruct bmbts from the rmapbt, in which case we don't want
the rmapbt update.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Freed extents are unconditionally discarded when online discard is
enabled. Define XFS_BMAPI_NODISCARD to allow callers to bypass
discards when unnecessary. For example, this will be useful for
eofblocks trimming.
This patch does not change behavior.
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>
Signed-off-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>
Refactor the bmap validator into a more complete helper that looks for
extents that run off the end of the device, overflow into the next AG,
or have invalid flag states.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Instead of looking up extents to convert and calling xfs_bmapi_write on
each of them just let xfs_bmapi_write handle the full range. To make
this robust add a new XFS_BMAPI_CONVERT_ONLY that only converts ranges
and never allocates blocks.
[darrick: shorten the stringified CONVERT_ONLY trace flag]
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>
Add a new xfs_iext_cursor structure to hide the direct extent map
index manipulations. In addition to the existing lookup/get/insert/
remove and update routines new primitives to get the first and last
extent cursor, as well as moving up and down by one extent are
provided. Also new are convenience to increment/decrement the
cursor and retreive the new extent, as well as to peek into the
previous/next extent without updating the cursor and last but not
least a macro to iterate over all extents in a fork.
[darrick: rename for_each_iext to for_each_xfs_iext]
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>
xfs_iread_extents is just a trivial wrapper, there is no good reason
to keep the two separate.
[darrick: minor fixups having left xfs_bmbt_validate_extent intact]
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>
Instead do the actual left and right shift work in the callers, and just
keep a helper to update the bmap and rmap btrees as well as the in-core
extent list.
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>
Have a separate helper for insert vs collapse, as this prepares us for
simplifying the code in the next patches.
Also changed the done output argument to a bool intead of int for both
new functions.
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 define was always set to 1, which means looping until we reach is
was dead code from the start.
Also remove an initialization of next_fsb for the done case that doesn't
fit the new code flow - it was never checked by the caller in the done
case to start with.
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>
Instead of looping over all extents in some debug-only helper just
insert trace points into the loops that already exist in the calling
functions.
Also split the xfs_extlist trace point into one each for reading and
writing extents from disk.
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 creates the right initial bmap state from the passed in inode
fork enum.
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 writeback rework in commit fbcc025613 ("xfs: Introduce
writeback context for writepages") introduced a subtle change in
behavior with regard to the block mapping used across the
->writepages() sequence. The previous xfs_cluster_write() code would
only flush pages up to EOF at the time of the writepage, thus
ensuring that any pages due to file-extending writes would be
handled on a separate cycle and with a new, updated block mapping.
The updated code establishes a block mapping in xfs_writepage_map()
that could extend beyond EOF if the file has post-eof preallocation.
Because we now use the generic writeback infrastructure and pass the
cached mapping to each writepage call, there is no implicit EOF
limit in place. If eofblocks trimming occurs during ->writepages(),
any post-eof portion of the cached mapping becomes invalid. The
eofblocks code has no means to serialize against writeback because
there are no pages associated with post-eof blocks. Therefore if an
eofblocks trim occurs and is followed by a file-extending buffered
write, not only has the mapping become invalid, but we could end up
writing a page to disk based on the invalid mapping.
Consider the following sequence of events:
- A buffered write creates a delalloc extent and post-eof
speculative preallocation.
- Writeback starts and on the first writepage cycle, the delalloc
extent is converted to real blocks (including the post-eof blocks)
and the mapping is cached.
- The file is closed and xfs_release() trims post-eof blocks. The
cached writeback mapping is now invalid.
- Another buffered write appends the file with a delalloc extent.
- The concurrent writeback cycle picks up the just written page
because the writeback range end is LLONG_MAX. xfs_writepage_map()
attributes it to the (now invalid) cached mapping and writes the
data to an incorrect location on disk (and where the file offset is
still backed by a delalloc extent).
This problem is reproduced by xfstests test generic/464, which
triggers racing writes, appends, open/closes and writeback requests.
To address this problem, trim the mapping used during writeback to
within EOF when the mapping is validated. This ensures the mapping
is revalidated for any pages encountered beyond EOF as of the time
the current mapping was cached or last validated.
Reported-by: Eryu Guan <eguan@redhat.com>
Diagnosed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-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>
In a pathological scenario where we are trying to bunmapi a single
extent in which every other block is shared, it's possible that trying
to unmap the entire large extent in a single transaction can generate so
many EFIs that we overflow the transaction reservation.
Therefore, use a heuristic to guess at the number of blocks we can
safely unmap from a reflink file's data fork in an single transaction.
This should prevent problems such as the log head slamming into the tail
and ASSERTs that trigger because we've exceeded the transaction
reservation.
Note that since bunmapi can fail to unmap the entire range, we must also
teach the deferred unmap code to roll into a new transaction whenever we
get low on reservation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[hch: random edits, all bugs are my fault]
Signed-off-by: Christoph Hellwig <hch@lst.de>
