xfs: make xfs_free_eofblocks() non-static, return EAGAIN on trylock failure

Turn xfs_free_eofblocks() into a non-static function, return EAGAIN to
indicate trylock failure and make sure this error is not propagated in
xfs_release().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_vnodeops.c

@@ -151,7 +151,7 @@ xfs_readlink(
  * when the link count isn't zero and by xfs_dm_punch_hole() when
  * punching a hole to EOF.
  */
-STATIC int
+int
 xfs_free_eofblocks(
 	xfs_mount_t	*mp,
 	xfs_inode_t	*ip,
@@ -200,7 +200,7 @@ xfs_free_eofblocks(
 		if (need_iolock) {
 			if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
 				xfs_trans_cancel(tp, 0);
-				return 0;
+				return EAGAIN;
 			}
 		}
 
@@ -463,7 +463,7 @@ xfs_release(
 			return 0;
 
 		error = xfs_free_eofblocks(mp, ip, true);
-		if (error)
+		if (error && error != EAGAIN)
 			return error;
 
 		/* delalloc blocks after truncation means it really is dirty */

fs/xfs/xfs_vnodeops.h

@@ -57,5 +57,6 @@ int xfs_flush_pages(struct xfs_inode *ip, xfs_off_t first,
 int xfs_wait_on_pages(struct xfs_inode *ip, xfs_off_t first, xfs_off_t last);
 
 int xfs_zero_eof(struct xfs_inode *, xfs_off_t, xfs_fsize_t);
+int xfs_free_eofblocks(struct xfs_mount *, struct xfs_inode *, bool);
 
 #endif /* _XFS_VNODEOPS_H */