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@xxxxxx>
---
fs/xfs/xfs_iomap.c | 27 +++++++++++++++++++--------
1 file 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);
--
2.14.2
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