xfs: fix the symbolic link assert in xfs_ifree

race_xfs_readlink(ip);
+

Quoted 2 lines · Mark Tinguely

race_xfs_readlink(ip);
+

Adding an extended attribute to a symbolic link can force that link to an remote extent. xfs_inactive() incorrectly assumes that any symbolic link small enough to be in the inode core is incore, resulting in the remote extent to not be removed. xfs_ifree() will assert on presence of this leaked remote extent.

Signed-off-by Mark Tinguely <[email protected]>

fs/xfs/xfs_symlink.c +6 -0

+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return XFS_ERROR(EIO);
+

fs/xfs/xfs_symlink.c +4 -0

+		ASSERT(0);
+		return XFS_ERROR(EFSCORRUPTED);
+	}
+

+}
Index: b/fs/xfs/xfs_symlink.h
===================================================================

fs/xfs/xfs_symlink.h +1 -1

@@ -60,7 +60,7 @@ extern const struct xfs_buf_ops xfs_syml
 int xfs_symlink(struct xfs_inode *dp, struct xfs_name *link_name,
 		const char *target_path, umode_t mode, struct xfs_inode **ipp);
 int xfs_readlink(struct xfs_inode *ip, char *link);
-int xfs_inactive_symlink_rmt(struct xfs_inode *ip, struct xfs_trans **tpp);
+int xfs_inactive_symlink(struct xfs_inode *ip, struct xfs_trans **tpp);
 
 #endif /* __KERNEL__ */
 #endif /* __XFS_SYMLINK_H */

Index: b/fs/xfs/xfs_trace.h
===================================================================

Quoted 7 lines · Mark Tinguely

Adding an extended attribute to a symbolic link can force that link to an remote extent. xfs_inactive() incorrectly assumes that any symbolic link small enough to be in the inode core is incore, resulting in the remote extent to not be removed. xfs_ifree() will assert on presence of this leaked remote extent.

Signed-off-by Mark Tinguely<[email protected]>

.....

fs/xfs/xfs_symlink.c xfs_inactive_symlink_rmt( · line 733

Quoted 10 lines

fs/xfs/xfs_symlink.c +10 -0

+/*
+ * xfs_inactive_symlink - free a symlink
+ */
+int
+xfs_inactive_symlink(
+	struct xfs_inode	*ip,
+	struct xfs_trans	**tp)
+{
+	struct xfs_mount *mp = ip->i_mount;
+	xfs_fsize_t	pathlen;

int will do here - it can't be more than MAXPATHLEN = 1024, and this gets rid of the casts in the error print.

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+	trace_xfs_readlink(ip);

trace_xfs_inactive_symlink, as you mentioned ;)

Quoted 7 lines

fs/xfs/xfs_symlink.c +6 -0

+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return XFS_ERROR(EIO);
+

fs/xfs/xfs_symlink.c xfs_inactive_symlink_rmt( · line 751

Quoted 10 lines

fs/xfs/xfs_symlink.c +10 -0

+	/*
+	 * Zero length symlinks _can_ exist.
+	 */
+	pathlen = ip->i_d.di_size;
+	if (!pathlen)
+		return 0;
+
+	if (pathlen<  0 || pathlen>  MAXPATHLEN) {
+		xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
+			 __func__, (unsigned long long) ip->i_ino,

^ whitespace

fs/xfs/xfs_symlink.c xfs_inactive_symlink_rmt( · line 752

Quoted 1 line

fs/xfs/xfs_symlink.c +1 -0

+			 (long long) pathlen);

Can we change this to a hex-based inode number (much easier to read) and the pathlen cast can go away if you use an int. i.e.:

		xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
			 __func__, (unsigned long long)ip->i_ino, pathlen);

Quoted 4 lines

fs/xfs/xfs_symlink.c +4 -0

+		ASSERT(0);
+		return XFS_ERROR(EFSCORRUPTED);
+	}
+

fs/xfs/xfs_symlink.c xfs_inactive_symlink_rmt( · line 766

Quoted 10 lines

fs/xfs/xfs_symlink.c +10 -0

+	if (ip->i_df.if_flags&  XFS_IFINLINE) {
+		if (ip->i_df.if_bytes>  0)
+			xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
+					  XFS_DATA_FORK);
+		ASSERT(ip->i_df.if_bytes == 0);
+		return 0;
+	}
+
+	/* remove the remote symlink */
+	return(xfs_inactive_symlink_rmt(ip, tp));

And no () around xfs_inactive_symlink_rmt().

Quoted 19 lines

+}
Index: b/fs/xfs/xfs_symlink.h
===================================================================

fs/xfs/xfs_symlink.h +1 -1

@@ -60,7 +60,7 @@ extern const struct xfs_buf_ops xfs_syml
  int xfs_symlink(struct xfs_inode *dp, struct xfs_name *link_name,
  		const char *target_path, umode_t mode, struct xfs_inode **ipp);
  int xfs_readlink(struct xfs_inode *ip, char *link);
-int xfs_inactive_symlink_rmt(struct xfs_inode *ip, struct xfs_trans **tpp);
+int xfs_inactive_symlink(struct xfs_inode *ip, struct xfs_trans **tpp);
 
  #endif /* __KERNEL__ */
  #endif /* __XFS_SYMLINK_H */

Index: b/fs/xfs/xfs_trace.h
===================================================================

fs/xfs/xfs_trace.h DEFINE_INODE_EVENT(xfs_inode_set_eofbloc · line 598

Quoted 5 lines

fs/xfs/xfs_trace.h +2 -0

@@ -594,6 +594,8 @@ DEFINE_INODE_EVENT(xfs_inode_set_eofbloc
  DEFINE_INODE_EVENT(xfs_inode_clear_eofblocks_tag);
  DEFINE_INODE_EVENT(xfs_inode_free_eofblocks_invalid);
 
+DEFINE_INODE_EVENT(xfs_symlink_inactive);
+

No need for the extra whitespace, just put it hard up against the other DEFINE_INODE_EVENT()s. Might be better to put it directly after the readlink trace definition.

Cheers,

Dave.