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authorChristoph Hellwig <hch@lst.de>2018-03-01 23:12:45 +0100
committerDarrick J. Wong <darrick.wong@oracle.com>2018-03-01 23:12:45 +0100
commitff3d8b9c4cb95180ae6ef9eed28409840525b9fa (patch)
tree14585938c73fbce45ff05877544aaab6e2c17503 /fs/xfs/xfs_iomap.c
parentxfs: don't start out with the exclusive ilock for direct I/O (diff)
downloadlinux-ff3d8b9c4cb95180ae6ef9eed28409840525b9fa.tar.xz
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xfs: don't block on the ilock for RWF_NOWAIT
Fix xfs_file_iomap_begin to trylock the ilock if IOMAP_NOWAIT is passed, so that we don't block io_submit callers. Signed-off-by: Christoph Hellwig <hch@lst.de> 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>
Diffstat (limited to 'fs/xfs/xfs_iomap.c')
-rw-r--r--fs/xfs/xfs_iomap.c27
1 files changed, 19 insertions, 8 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index ee01859b77a5..046469fcc1b8 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -970,6 +970,15 @@ static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags)
*/
if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO)))
return true;
+
+ /*
+ * Extents not yet cached requires exclusive access, don't block.
+ * This is an opencoded xfs_ilock_data_map_shared() to cater for the
+ * non-blocking behaviour.
+ */
+ if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
+ !(ip->i_df.if_flags & XFS_IFEXTENTS))
+ return true;
return false;
}
@@ -998,16 +1007,18 @@ xfs_file_iomap_begin(
return xfs_file_iomap_begin_delay(inode, offset, length, iomap);
}
- if (need_excl_ilock(ip, flags)) {
+ if (need_excl_ilock(ip, flags))
lockmode = XFS_ILOCK_EXCL;
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- } else {
- lockmode = xfs_ilock_data_map_shared(ip);
- }
+ else
+ lockmode = XFS_ILOCK_SHARED;
- if ((flags & IOMAP_NOWAIT) && !(ip->i_df.if_flags & XFS_IFEXTENTS)) {
- error = -EAGAIN;
- goto out_unlock;
+ if (flags & IOMAP_NOWAIT) {
+ if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+ return -EAGAIN;
+ if (!xfs_ilock_nowait(ip, lockmode))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, lockmode);
}
ASSERT(offset <= mp->m_super->s_maxbytes);