diff options
| author | Christoph Hellwig <hch@lst.de> | 2019-10-19 09:09:47 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-10-21 09:04:58 -0700 |
| commit | 1e190f8e8098b95d9f48f91db8b618a2d371c13a (patch) | |
| tree | be95f2994bd1575a6c8ff4a3e7ff2b2ddc30fe0a | |
| parent | 5c5b6f7585d272a2fccf4ccf9b85251f6fbeb124 (diff) | |
xfs: improve the IOMAP_NOWAIT check for COW inodesxfs-5.5-merge-2
Only bail out once we know that a COW allocation is actually required,
similar to how we handle normal data fork 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>
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 6b429bfd5bb8..bf0c7756ac90 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -693,15 +693,8 @@ xfs_ilock_for_iomap( * COW writes may allocate delalloc space or convert unwritten COW * extents, so we need to make sure to take the lock exclusively here. */ - if (xfs_is_cow_inode(ip) && is_write) { - /* - * FIXME: It could still overwrite on unshared extents and not - * need allocation. - */ - if (flags & IOMAP_NOWAIT) - return -EAGAIN; + if (xfs_is_cow_inode(ip) && is_write) mode = XFS_ILOCK_EXCL; - } /* * Extents not yet cached requires exclusive access, don't block. This @@ -769,12 +762,6 @@ xfs_direct_write_iomap_begin( if (offset + length > i_size_read(inode)) iomap_flags |= IOMAP_F_DIRTY; - /* - * Lock the inode in the manner required for the specified operation and - * check for as many conditions that would result in blocking as - * possible. This removes most of the non-blocking checks from the - * mapping code below. - */ error = xfs_ilock_for_iomap(ip, flags, &lockmode); if (error) return error; @@ -784,11 +771,11 @@ xfs_direct_write_iomap_begin( if (error) goto out_unlock; - /* - * Break shared extents if necessary. Checks for non-blocking IO have - * been done up front, so we don't need to do them here. - */ if (imap_needs_cow(ip, flags, &imap, nimaps)) { + error = -EAGAIN; + if (flags & IOMAP_NOWAIT) + goto out_unlock; + /* may drop and re-acquire the ilock */ error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared, &lockmode, flags & IOMAP_DIRECT); |