summaryrefslogtreecommitdiff
path: root/fs/xfs/libxfs/xfs_refcount.c
AgeCommit message (Collapse)AuthorFilesLines
2017-09-01xfs: remove the ip argument to xfs_defer_finishChristoph Hellwig1-1/+1
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>
2017-07-21xfs: check _alloc_read_agf buffer pointer before usingDarrick J. Wong1-0/+4
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>
2017-06-28xfs: remove unneeded parameter from XFS_TEST_ERRORDarrick J. Wong1-4/+2
Since we moved the injected error frequency controls to the mountpoint, we can get rid of the last argument to XFS_TEST_ERROR. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-06-19xfs: try to avoid blowing out the transaction reservation when bunmaping a ↵Darrick J. Wong1-9/+1
shared extent 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>
2017-05-19xfs: avoid mount-time deadlock in CoW extent recoveryDarrick J. Wong1-12/+31
If a malicious user corrupts the refcount btree to cause a cycle between different levels of the tree, the next mount attempt will deadlock in the CoW recovery routine while grabbing buffer locks. We can use the ability to re-grab a buffer that was previous locked to a transaction to avoid deadlocks, so do that here. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2016-10-10xfs: rework refcount cow recovery error handlingDarrick J. Wong1-11/+9
The error handling in xfs_refcount_recover_cow_leftovers is confused and can potentially leak memory, so rework it to release resources correctly on error. 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>
2016-10-06xfs: store in-progress CoW allocations in the refcount btreeDarrick J. Wong1-10/+443
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>
2016-10-03xfs: introduce reflink utility functionsDarrick J. Wong1-0/+102
These functions will be used by the other reflink functions to find the maximum length of a range of shared blocks. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: connect refcount adjust functions to upper layersDarrick J. Wong1-0/+174
Plumb in the upper level interface to schedule and finish deferred refcount operations via the deferred ops mechanism. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: adjust refcount of an extent of blocks in refcount btreeDarrick J. Wong1-0/+814
Provide functions to adjust the reference counts for an extent of physical blocks stored in the refcount btree. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: add refcount btree operationsDarrick J. Wong1-0/+177
Implement the generic btree operations required to manipulate refcount btree blocks. The implementation is similar to the bmapbt, though it will only allocate and free blocks from the AG. Since the refcount root and level fields are separate from the existing roots and levels array, they need a separate logging flag. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: fix logging of AGF refcount btree fields] Signed-off-by: Christoph Hellwig <hch@lst.de>