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path: root/fs/xfs/xfs_reflink.c
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2018-01-29xfs: check reflink allocation mappingsDarrick J. Wong
There's a really bad bug in xfs_reflink_allocate_cow -- if bmapi_write can return a zero error code but no mappings. This happens if there's an extent size hint (which causes allocation requests to be rounded to extsz granularity internally), but there wasn't a big enough chunk of free space to start filling at the extsz granularity and fill even one block of the range that we actually requested. In any case, if we got no mappings we can't possibly do anything useful with the contents of imap, so we must bail out with ENOSPC here. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29xfs: treat CoW fork operations as delalloc for quota accountingDarrick J. Wong
Since the CoW fork only exists in memory, it is incorrect to update the on-disk quota block counts when we modify the CoW fork. Unlike the data fork, even real extents in the CoW fork are only delalloc-style reservations (on-disk they're owned by the refcountbt) so they must not be tracked in the on disk quota info. Ensure the i_delayed_blks accounting reflects this too. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29xfs: only grab shared inode locks for source file during reflinkDarrick J. Wong
Reflink and dedupe operations remap blocks from a source file into a destination file. The destination file needs exclusive locks on all levels because we're updating its block map, but the source file isn't undergoing any block map changes so we can use a shared lock. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29xfs: allow xfs_lock_two_inodes to take different EXCL/SHARED modesDarrick J. Wong
Refactor xfs_lock_two_inodes to take separate locking modes for each inode. Specifically, this enables us to take a SHARED lock on one inode and an EXCL lock on the other. The lock class (MMAPLOCK/ILOCK) must be the same for each inode. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29xfs: reflink should break pnfs leases before sharing blocksDarrick J. Wong
Before we share blocks between files, we need to break the pnfs leases on the layout before we start slicing and dicing the block map. The structure of this function sets us up for the lock contention reduction in the next patch. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29xfs: call xfs_qm_dqattach before performing reflink operationsDarrick J. Wong
Ensure that we've attached all the necessary dquots before performing reflink operations so that quota accounting is accurate. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-21xfs: set cowblocks tag for direct cow writes tooDarrick J. Wong
If a user performs a direct CoW write, we end up loading the CoW fork with preallocated extents. Therefore, we must set the cowblocks tag so that they can be cleared out if we run low on space. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-14xfs: allow CoW remap transactions to use reserve blocksDarrick J. Wong
Since we as yet have no way of holding on to the indlen blocks that are reserved as part of CoW fork delalloc reservations, let the CoW remap transaction dip into the reserves so that we avoid failing writes. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-14xfs: avoid infinite loop when cancelling CoW blocks after writeback failureDarrick J. Wong
When we're cancelling a cow range, we don't always delete each extent that we iterate, so we have to move icur backwards in the list to avoid an infinite loop. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-14xfs: relax is_reflink_inode assert in xfs_reflink_find_cow_mappingDarrick J. Wong
We don't hold the ilock through the entire sequence of xfs_writepage_map -> xfs_map_cow -> xfs_reflink_find_cow_mapping. This means that we can race with another thread that is trying to clear the inode reflink flag, with the result that the flag is set for the xfs_map_cow check but cleared before we get to the assert in find_cow_mapping. When this happens, we blow the assert even though everything is fine. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-14xfs: remove dest file's post-eof preallocations before reflinkingDarrick J. Wong
If we try to reflink into a file with post-eof preallocations at an offset well past the preallocations, we increase i_size as one would expect. However, those allocations do not have page cache backing them, so they won't get cleaned out on their own. This leads to asserts in the collapse/insert range code and xfs_destroy_inode when they encounter delalloc extents they weren't expecting to find. Since there are plenty of other places where we dump those post-eof blocks, do the same to the reflink destination file before we start remapping extents. This was found by adding clonerange support to fsstress and running it in write-only mode. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-12-08fs: xfs: remove duplicate includesPravin Shedge
These duplicate includes have been found with scripts/checkincludes.pl but they have been removed manually to avoid removing false positives. Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-06xfs: simplify xfs_reflink_convert_cowChristoph Hellwig
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>
2017-11-06xfs: iterate backwards in xfs_reflink_cancel_cow_blocksChristoph Hellwig
Match the iteration order for extent deletion in the truncate and reflink I/O completion path. This also happens to make implementing the new incore extent list a lot easier. 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>
2017-11-06xfs: introduce the xfs_iext_cursor abstractionChristoph Hellwig
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>
2017-10-26xfs: add a new xfs_iext_lookup_extent_before helperChristoph Hellwig
This helper looks up the last extent the covers space before the passed in block number. This is useful for truncate and similar operations that operate backwards over the extent list. For xfs_bunmapi it also is a slight optimization as we can return early if there are not extents at or below the end of the to be truncated range. 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>
2017-10-03 xfs: handle racy AIO in xfs_reflink_end_cowChristoph Hellwig
If we got two AIO writes into a COW area the second one might not have any COW extents left to convert. Handle that case gracefully instead of triggering an assert or accessing beyond the bounds of the 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>
2017-09-01xfs: remove the ip argument to xfs_defer_finishChristoph Hellwig
And instead require callers to explicitly join the inode using xfs_defer_ijoin. Also consolidate the defer error handling in a few places using a goto label. 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>
2017-07-20xfs: check _alloc_read_agf buffer pointer before usingDarrick J. Wong
In some circumstances, _alloc_read_agf can return an error code of zero but also a null AGF buffer pointer. Check for this and jump out. Fixes-coverity-id: 1415250 Fixes-coverity-id: 1415320 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-20xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_writeDarrick J. Wong
We must initialize the firstfsb parameter to _bmapi_write so that it doesn't incorrectly treat stack garbage as a restriction on which AGs it can search for free space. Fixes-coverity-id: 1402025 Fixes-coverity-id: 1415167 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-19xfs: separate function to check if inode shares extentsDarrick J. Wong
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>
2017-06-19xfs: reflink find shared should take a transactionDarrick J. Wong
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>
2017-05-03xfs: reserve enough blocks to handle btree splits when remappingDarrick J. Wong
In xfs_reflink_end_cow, we erroneously reserve only enough blocks to handle adding 1 extent. This is problematic if we fragment free space, have to do CoW, and then have to perform multiple bmap btree expansions. Furthermore, the BUI recovery routine doesn't reserve /any/ blocks to handle btree splits, so log recovery fails after our first error causes the filesystem to go down. Therefore, refactor the transaction block reservation macros until we have a macro that works for our deferred (re)mapping activities, and fix both problems by using that macro. With 1k blocks we can hit this fairly often in g/187 if the scratch fs is big enough. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-04-03xfs: factor out a xfs_bmap_is_real_extent helperChristoph Hellwig
This checks for all the non-normal extent types, including handling both encodings of delayed allocations. 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>
2017-03-07xfs: only reclaim unwritten COW extents periodicallyChristoph Hellwig
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>
2017-02-16xfs: fix uninitialized variable in _reflink_convert_cowDarrick J. Wong
Fix an uninitialize variable. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-09xfs: update ctime and mtime on clone destinatation inodesChristoph Hellwig
We're changing both metadata and data, so we need to update the timestamps for clone operations. Dedupe on the other hand does not change file data, and only changes invisible metadata so the timestamps should not be updated. This follows existing btrfs behavior. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: remove redundant is_dedupe test] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-06xfs: allocate direct I/O COW blocks in iomap_beginChristoph Hellwig
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>
2017-02-06xfs: go straight to real allocations for direct I/O COW writesChristoph Hellwig
When we allocate COW fork blocks for direct I/O writes we currently first create a delayed allocation, and then convert it to a real allocation once we've got the delayed one. As there is no good reason for that this patch instead makes use call xfs_bmapi_write from the COW allocation path. The only interesting bits are a few tweaks the low-level allocator to allow for this, most notably the need to remove the call to xfs_bmap_extsize_align for the cowextsize in xfs_bmap_btalloc - for the existing convert case it's a no-op, but for the direct allocation case it would blow up our block reservation way beyond what we reserved for the transaction. 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>
2017-02-06xfs: return the converted extent in __xfs_reflink_convert_cowChristoph Hellwig
We'll need it for the direct I/O code. Also rename the function to xfs_reflink_convert_cow_extent to describe it a bit better. 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>
2017-02-02xfs: mark speculative prealloc CoW fork extents unwrittenDarrick J. Wong
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>
2016-12-22vfs: fix isize/pos/len checks for reflink & dedupeDarrick J. Wong
Strengthen the checking of pos/len vs. i_size, clarify the return values for the clone prep function, and remove pointless code. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "In this pile: - autofs-namespace series - dedupe stuff - more struct path constification" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features ocfs2: charge quota for reflinked blocks ocfs2: fix bad pointer cast ocfs2: always unlock when completing dio writes ocfs2: don't eat io errors during _dio_end_io_write ocfs2: budget for extent tree splits when adding refcount flag ocfs2: prohibit refcounted swapfiles ocfs2: add newlines to some error messages ocfs2: convert inode refcount test to a helper simple_write_end(): don't zero in short copy into uptodate exofs: don't mess with simple_write_{begin,end} 9p: saner ->write_end() on failing copy into non-uptodate page fix gfs2_stuffed_write_end() on short copies fix ceph_write_end() nfs_write_end(): fix handling of short copies vfs: refactor clone/dedupe_file_range common functions fs: try to clone files first in vfs_copy_file_range vfs: misc struct path constification namespace.c: constify struct path passed to a bunch of primitives quota: constify struct path in quota_on ...
2016-12-09vfs: refactor clone/dedupe_file_range common functionsDarrick J. Wong
Hoist both the XFS reflink inode state and preparation code and the XFS file blocks compare functions into the VFS so that ocfs2 can take advantage of it for reflink and dedupe. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-11-30xfs: remove i_iolock and use i_rwsem in the VFS inode insteadChristoph Hellwig
This patch drops the XFS-own i_iolock and uses the VFS i_rwsem which recently replaced i_mutex instead. This means we only have to take one lock instead of two in many fast path operations, and we can also shrink the xfs_inode structure. Thanks to the xfs_ilock family there is very little churn, the only thing of note is that we need to switch to use the lock_two_directory helper for taking the i_rwsem on two inodes in a few places to make sure our lock order matches the one used in the VFS. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Jens Axboe <axboe@fb.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-28xfs: clean up cow fork reservation and tag inodes correctlyBrian Foster
COW fork reservation is implemented via delayed allocation. The code is modeled after the traditional delalloc allocation code, but is slightly different in terms of how preallocation occurs. Rather than post-eof speculative preallocation, COW fork preallocation is implemented via a COW extent size hint that is designed to minimize fragmentation as a reflinked file is split over time. xfs_reflink_reserve_cow() still uses logic that is oriented towards dealing with post-eof speculative preallocation, however, and is stale or not necessarily correct. First, the EOF alignment to the COW extent size hint is implemented in xfs_bmapi_reserve_delalloc() (which does so correctly by aligning the start and end offsets) and so is not necessary in xfs_reflink_reserve_cow(). The backoff and retry logic on ENOSPC is also ineffective for the same reason, as xfs_bmapi_reserve_delalloc() will simply perform the same allocation request on the retry. Finally, since the COW extent size hint aligns the start and end offset of the range to allocate, the end_fsb != orig_end_fsb logic is not sufficient. Indeed, if a write request happens to end on an aligned offset, it is possible that we do not tag the inode for COW preallocation even though xfs_bmapi_reserve_delalloc() may have preallocated at the start offset. Kill the unnecessary, duplicate code in xfs_reflink_reserve_cow(). Remove the inode tag logic as well since xfs_bmapi_reserve_delalloc() has been updated to tag the inode correctly. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-28xfs: track preallocation separately in xfs_bmapi_reserve_delalloc()Brian Foster
Speculative preallocation is currently processed entirely by the callers of xfs_bmapi_reserve_delalloc(). The caller determines how much preallocation to include, adjusts the extent length and passes down the resulting request. While this works fine for post-eof speculative preallocation, it is not as reliable for COW fork preallocation. COW fork preallocation is implemented via the cowextszhint, which aligns the start offset as well as the length of the extent. Further, it is difficult for the caller to accurately identify when preallocation occurs because the returned extent could have been merged with neighboring extents in the fork. To simplify this situation and facilitate further COW fork preallocation enhancements, update xfs_bmapi_reserve_delalloc() to take a separate preallocation parameter to incorporate into the allocation request. The preallocation blocks value is tacked onto the end of the request and adjusted to accommodate neighboring extents and extent size limits. Since xfs_bmapi_reserve_delalloc() now knows precisely how much preallocation was included in the allocation, it can also tag the inodes appropriately to support preallocation reclaim. Note that xfs_bmapi_reserve_delalloc() callers are not yet updated to use the preallocation mechanism. This patch should not change behavior outside of correctly tagging reflink inodes when start offset preallocation occurs (which the caller does not handle correctly). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-28xfs: always succeed when deduping zero bytesDarrick J. Wong
It turns out that btrfs and xfs had differing interpretations of what to do when the dedupe length is zero. Change xfs to follow btrfs' semantics so that the userland interface is consistent. 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>
2016-11-24xfs: use new extent lookup helpers in xfs_reflink_end_cowChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in xfs_reflink_cancel_cow_blocksChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in xfs_reflink_trim_irec_to_next_cowChristoph Hellwig
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>
2016-11-24xfs: cleanup xfs_reflink_find_cow_mappingChristoph Hellwig
Use xfs_iext_lookup_extent to look up the extent, drop a useless check, drop a unneeded return value and clean up the general style a little bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: use new extent lookup helpers in __xfs_reflink_reserve_cowChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-24xfs: remove prev argument to xfs_bmapi_reserve_delallocChristoph Hellwig
We can easily lookup the previous extent for the cases where we need it, which saves the callers from looking it up for us later in the series. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-08xfs: provide helper for counting extents from if_bytesEric Sandeen
The open-coded pattern: ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t) is all over the xfs code; provide a new helper xfs_iext_count(ifp) to count the number of inline extents in an inode fork. [dchinner: pick up several missed conversions] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-08xfs: don't skip cow forks w/ delalloc blocks in cowblocks scanBrian Foster
The cowblocks background scanner currently clears the cowblocks tag for inodes without any real allocations in the cow fork. This excludes inodes with only delalloc blocks in the cow fork. While we might never expect to clear delalloc blocks from the cow fork in the background scanner, it is not necessarily correct to clear the cowblocks tag from such inodes. For example, if the background scanner happens to process an inode between a buffered write and writeback, the scanner catches the inode in a state after delalloc blocks have been allocated to the cow fork but before the delalloc blocks have been converted to real blocks by writeback. The background scanner then incorrectly clears the cowblocks tag, even if part of the aforementioned delalloc reservation will not be remapped to the data fork (i.e., extra blocks due to the cowextsize hint). This means that any such additional blocks in the cow fork might never be reclaimed by the background scanner and could persist until the inode itself is reclaimed. To address this problem, only skip and clear inodes without any cow fork allocations whatsoever from the background scanner. While we generally do not want to cancel delalloc reservations from the background scanner, the pagecache dirty check following the cowblocks check should prevent that situation. If we do end up with delalloc cow fork blocks without a dirty address space mapping, this is probably an indication that something has gone wrong and the blocks should be reclaimed, as they may never be converted to a real allocation. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-24xfs: clear cowblocks tag when cow fork is emptiedBrian Foster
The background cowblocks scan job takes care of scanning for inodes with potentially lingering blocks in the cow fork and clearing them out. If the background scanner reclaims the cow fork blocks, however, it doesn't immediately clear the cowblocks tag from the inode. Instead, the inode remains tagged until the background scanner comes around again, discovers the inode cow fork has no blocks, clears the tag and fires the trace_xfs_inode_free_cowblocks_invalid() tracepoint to indicate that the inode may have been incorrectly tagged. This is not a major functional problem as the tag is ultimately cleared. Nonetheless, clear the tag when an inode cow fork is explicitly emptied to avoid the extra round trip through the background scanner and spurious "invalid" tracepoint. 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: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: optimize xfs_reflink_end_cowChristoph Hellwig
Instead of doing a full extent list search for each extent that is to be deleted using xfs_bmapi_read and then doing another one inside of xfs_bunmapi_cow use the same scheme that xfs_bumapi uses: look up the last extent to be deleted and then use the extent index to walk downward until we are outside the range to be deleted. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: optimize xfs_reflink_cancel_cow_blocksChristoph Hellwig
Rewrite xfs_reflink_cancel_cow_blocks so that we only do a search for the first extent in the extent list and then iterate over the remaining extents using the extent index, passing the extent we operate on directly to xfs_bmap_del_extent_delay or xfs_bmap_del_extent_cow instead of going through xfs_bunmapi and doing yet another extent list lookup. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20xfs: refactor xfs_bunmapi_cowChristoph Hellwig
Split out two helpers for deleting delayed or real extents from the COW fork. This allows to call them directly from xfs_reflink_cow_end_io once that function is refactored to iterate the extent tree. It will also allow to reuse the delalloc deletion from xfs_bunmapi in the future. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>