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* xfs: handle racy AIO in xfs_reflink_end_cowChristoph Hellwig2017-10-031-1/+8
| | | | | | | | | | 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>
* xfs: remove the ip argument to xfs_defer_finishChristoph Hellwig2017-09-011-4/+7
| | | | | | | | | | 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>
* xfs: check _alloc_read_agf buffer pointer before usingDarrick J. Wong2017-07-201-0/+2
| | | | | | | | | | 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>
* xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_writeDarrick J. Wong2017-07-201-1/+1
| | | | | | | | | | | 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>
* xfs: separate function to check if inode shares extentsDarrick J. Wong2017-06-191-36/+52
| | | | | | | | | | 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>
* xfs: reflink find shared should take a transactionDarrick J. Wong2017-06-191-7/+8
| | | | | | | | | | 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>
* xfs: reserve enough blocks to handle btree splits when remappingDarrick J. Wong2017-05-031-2/+16
| | | | | | | | | | | | | | | | | | | 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>
* xfs: factor out a xfs_bmap_is_real_extent helperChristoph Hellwig2017-04-031-17/+4
| | | | | | | | | 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>
* xfs: only reclaim unwritten COW extents periodicallyChristoph Hellwig2017-03-071-7/+16
| | | | | | | | | | | | | 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>
* xfs: fix uninitialized variable in _reflink_convert_cowDarrick J. Wong2017-02-161-1/+1
| | | | | | | | 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>
* xfs: update ctime and mtime on clone destinatation inodesChristoph Hellwig2017-02-091-3/+9
| | | | | | | | | | | | | | 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>
* xfs: allocate direct I/O COW blocks in iomap_beginChristoph Hellwig2017-02-061-92/+54
| | | | | | | | | 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>
* xfs: go straight to real allocations for direct I/O COW writesChristoph Hellwig2017-02-061-28/+66
| | | | | | | | | | | | | | | | | | 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>
* xfs: return the converted extent in __xfs_reflink_convert_cowChristoph Hellwig2017-02-061-6/+5
| | | | | | | | | 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>
* xfs: mark speculative prealloc CoW fork extents unwrittenDarrick J. Wong2017-02-021-8/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* vfs: fix isize/pos/len checks for reflink & dedupeDarrick J. Wong2016-12-221-1/+1
| | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-12-171-210/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * vfs: refactor clone/dedupe_file_range common functionsDarrick J. Wong2016-12-091-204/+9
| | | | | | | | | | | | | | | | 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>
* | xfs: remove i_iolock and use i_rwsem in the VFS inode insteadChristoph Hellwig2016-11-301-9/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: clean up cow fork reservation and tag inodes correctlyBrian Foster2016-11-281-26/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: track preallocation separately in xfs_bmapi_reserve_delalloc()Brian Foster2016-11-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: always succeed when deduping zero bytesDarrick J. Wong2016-11-281-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: use new extent lookup helpers in xfs_reflink_end_cowChristoph Hellwig2016-11-241-10/+6
| | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* | xfs: use new extent lookup helpers in xfs_reflink_cancel_cow_blocksChristoph Hellwig2016-11-241-8/+4
| | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* | xfs: use new extent lookup helpers in xfs_reflink_trim_irec_to_next_cowChristoph Hellwig2016-11-241-21/+12
| | | | | | | | | | | | | | | | | | | | 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>
* | xfs: cleanup xfs_reflink_find_cow_mappingChristoph Hellwig2016-11-241-23/+10
| | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: use new extent lookup helpers in __xfs_reflink_reserve_cowChristoph Hellwig2016-11-241-5/+7
| | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* | xfs: remove prev argument to xfs_bmapi_reserve_delallocChristoph Hellwig2016-11-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: provide helper for counting extents from if_bytesEric Sandeen2016-11-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | xfs: don't skip cow forks w/ delalloc blocks in cowblocks scanBrian Foster2016-11-081-34/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xfs: clear cowblocks tag when cow fork is emptiedBrian Foster2016-10-241-1/+5
| | | | | | | | | | | | | | | | | | | | | | 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>
* xfs: optimize xfs_reflink_end_cowChristoph Hellwig2016-10-201-63/+56
| | | | | | | | | | | | | | | 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>
* xfs: optimize xfs_reflink_cancel_cow_blocksChristoph Hellwig2016-10-201-28/+23
| | | | | | | | | | | | | | | 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>
* xfs: refactor xfs_bunmapi_cowChristoph Hellwig2016-10-201-5/+0
| | | | | | | | | | | | | | 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>
* xfs: optimize writes to reflink filesChristoph Hellwig2016-10-201-84/+58
| | | | | | | | | | | | | | | | Instead of reserving space as the first thing in write_begin move it past reading the extent in the data fork. That way we only have to read from the data fork once and can reuse that information for trimming the extent to the shared/unshared boundary. Additionally this allows to easily limit the actual write size to said boundary, and avoid a roundtrip on the ilock. 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>
* xfs: handle "raw" delayed extents xfs_reflink_trim_around_sharedChristoph Hellwig2016-10-201-1/+2
| | | | | | | | | | | | | | Delalloc extents in the extent list contain the number of reserved indirect blocks in their startblock value and don't use the magic DELAYSTARTBLOCK constant. Ensure that xfs_reflink_trim_around_shared handles them properly by checking for isnullstartblock(). 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>
* xfs: merge xfs_reflink_remap_range and xfs_file_share_rangeChristoph Hellwig2016-10-201-40/+138
| | | | | | | | | | | | There is no clear division of responsibility between those functions, so just merge them into one to keep the code simple. Also move xfs_file_wait_for_io to xfs_reflink.c together with its only caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: move inode locking from xfs_reflink_remap_range to xfs_file_share_rangeChristoph Hellwig2016-10-201-15/+0
| | | | | | | | | | | | We need the iolock protection to stabilizie the IS_SWAPFILE and IS_IMMUTABLE values, as well as preventing new buffered writers re-dirtying the file data that we just wrote out. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: Fix uninitialized variable in xfs_reflink_reserve_cow_range()Geert Uytterhoeven2016-10-201-1/+1
| | | | | | | | | | | | | | | | | | | | with gcc 4.1.2: fs/xfs/xfs_reflink.c: In function xfs_reflink_reserve_cow_range: fs/xfs/xfs_reflink.c:327: warning: error may be used uninitialized in this function Indeed, if "count" is zero, the function will return an uninitialized error value. While "count" is unlikely to be zero, this function is called through the public iomap API. Hence fix this by preinitializing error to zero. Fixes: 2a06705cd5954030 ("xfs: create delalloc extents in CoW fork") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: fix error initializationDarrick J. Wong2016-10-101-1/+1
| | | | | | | | | | | | Eric Sandeen reported a gcc complaint about uninitialized error variables, so fix that. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: remove isize check from unshare operationDarrick J. Wong2016-10-101-12/+6
| | | | | | | | | | | | | Now that fallocate has an explicit unshare flag again, let's try to remove the inode reflink flag whenever the user unshares any part of a file since checking is cheap compared to the CoW. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: reduce stack usage of _reflink_clear_inode_flagDarrick J. Wong2016-10-101-24/+16
| | | | | | | | | | | | | The loop in _reflink_clear_inode_flag isn't necessary since we jump out if any part of any extent is shared. Remove the loop and we no longer need two maps, so we can save some stack use. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: check inode reflink flag before calling reflink functionsDarrick J. Wong2016-10-101-2/+2
| | | | | | | | | | | | There are a couple of places where we don't check the inode's reflink flag before calling into the reflink code. Fix those, and add some asserts so we don't make this mistake again. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: garbage collect old cowextsz reservationsDarrick J. Wong2016-10-051-0/+38
| | | | | | | | | | | | | | | | | | Trim CoW reservations made on behalf of a cowextsz hint if they get too old or we run low on quota, so long as we don't have dirty data awaiting writeback or directio operations in progress. Garbage collection of the cowextsize extents are kept separate from prealloc extent reaping because setting the CoW prealloc lifetime to a (much) higher value than the regular prealloc extent lifetime has been useful for combatting CoW fragmentation on VM hosts where the VMs experience bursty write behaviors and we can keep the utilization ratios low enough that we don't start to run out of space. IOWs, it benefits us to keep the CoW fork reservations around for as long as we can unless we run out of blocks or hit inode reclaim. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: don't allow reflink when the AG is low on spaceDarrick J. Wong2016-10-051-0/+35
| | | | | | | | | If the AG free space is down to the reserves, refuse to reflink our way out of space. Hopefully userspace will make a real copy and/or go elsewhere. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: create a separate cow extent size hint for the allocatorDarrick J. Wong2016-10-051-7/+34
| | | | | | | | | | | | | | | | | | | | | | Create a per-inode extent size allocator hint for copy-on-write. This hint is separate from the existing extent size hint so that CoW can take advantage of the fragmentation-reducing properties of extent size hints without disabling delalloc for regular writes. The extent size hint that's fed to the allocator during a copy on write operation is the greater of the cowextsize and regular extsize hint. During reflink, if we're sharing the entire source file to the entire destination file and the destination file doesn't already have a cowextsize hint, propagate the source file's cowextsize hint to the destination file. Furthermore, zero the bulkstat buffer prior to setting the fields so that we don't copy kernel memory contents into userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: unshare a range of blocks via fallocateDarrick J. Wong2016-10-051-0/+255
| | | | | | | | | | | Unshare all shared extents if the user calls fallocate with the new unshare mode flag set, so that we can guarantee that a subsequent write will not ENOSPC. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: pass inode instead of file to xfs_reflink_dirty_range, use iomap infrastructure for copy up] Signed-off-by: Christoph Hellwig <hch@lst.de>
* xfs: add dedupe range vfs functionDarrick J. Wong2016-10-051-1/+126
| | | | | | | | | | Define a VFS function which allows userspace to request that the kernel reflink a range of blocks between two files if the ranges' contents match. The function fits the new VFS ioctl that standardizes the checking for the btrfs EXTENT SAME ioctl. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: reflink extents from one file to anotherDarrick J. Wong2016-10-051-0/+428
| | | | | | | | | | Reflink extents from one file to another; that is to say, iteratively remove the mappings from the destination file, copy the mappings from the source file to the destination file, and increment the reference count of all the blocks that got remapped. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: store in-progress CoW allocations in the refcount btreeDarrick J. Wong2016-10-051-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | Due to the way the CoW algorithm in XFS works, there's an interval during which blocks allocated to handle a CoW can be lost -- if the FS goes down after the blocks are allocated but before the block remapping takes place. This is exacerbated by the cowextsz hint -- allocated reservations can sit around for a while, waiting to get used. Since the refcount btree doesn't normally store records with refcount of 1, we can use it to record these in-progress extents. In-progress blocks cannot be shared because they're not user-visible, so there shouldn't be any conflicts with other programs. This is a better solution than holding EFIs during writeback because (a) EFIs can't be relogged currently, (b) even if they could, EFIs are bound by available log space, which puts an unnecessary upper bound on how much CoW we can have in flight, and (c) we already have a mechanism to track blocks. At mount time, read the refcount records and free anything we find with a refcount of 1 because those were in-progress when the FS went down. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>