---

yaml
---
r: 108316
b: refs/heads/master
c: e1cccd9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1550d0b0b08bc34c0c37a86bd884b1a70782104e
+refs/heads/master: e1cccd917be7364f81b5dc4e33ee3a6e0db21a99

trunk/fs/xfs/xfs_dfrag.c

@@ -128,7 +128,6 @@ xfs_swap_extents(
 	xfs_swapext_t	*sxp)
 {
 	xfs_mount_t	*mp;
-	xfs_inode_t	*ips[2];
 	xfs_trans_t	*tp;
 	xfs_bstat_t	*sbp = &sxp->sx_stat;
 	bhv_vnode_t	*vp, *tvp;
@@ -153,16 +152,7 @@ xfs_swap_extents(
 	vp = VFS_I(ip);
 	tvp = VFS_I(tip);
 
-	/* Lock in i_ino order */
-	if (ip->i_ino < tip->i_ino) {
-		ips[0] = ip;
-		ips[1] = tip;
-	} else {
-		ips[0] = tip;
-		ips[1] = ip;
-	}
-
-	xfs_lock_inodes(ips, 2, lock_flags);
+	xfs_lock_two_inodes(ip, tip, lock_flags);
 	locked = 1;
 
 	/* Verify that both files have the same format */
@@ -265,7 +255,7 @@ xfs_swap_extents(
 		locked = 0;
 		goto error0;
 	}
-	xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
+	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
 
 	/*
 	 * Count the number of extended attribute blocks

trunk/fs/xfs/xfs_inode.h

@@ -531,6 +531,7 @@ void		xfs_iflush_all(struct xfs_mount *);
 void		xfs_ichgtime(xfs_inode_t *, int);
 xfs_fsize_t	xfs_file_last_byte(xfs_inode_t *);
 void		xfs_lock_inodes(xfs_inode_t **, int, uint);
+void		xfs_lock_two_inodes(xfs_inode_t *, xfs_inode_t *, uint);
 
 void		xfs_synchronize_atime(xfs_inode_t *);
 void		xfs_mark_inode_dirty_sync(xfs_inode_t *);

trunk/fs/xfs/xfs_vnodeops.c

@@ -1707,111 +1707,6 @@ xfs_create(
 	goto std_return;
 }
 
-#ifdef DEBUG
-/*
- * Some counters to see if (and how often) we are hitting some deadlock
- * prevention code paths.
- */
-
-int xfs_rm_locks;
-int xfs_rm_lock_delays;
-int xfs_rm_attempts;
-#endif
-
-/*
- * The following routine will lock the inodes associated with the
- * directory and the named entry in the directory. The locks are
- * acquired in increasing inode number.
- *
- * If the entry is "..", then only the directory is locked. The
- * vnode ref count will still include that from the .. entry in
- * this case.
- *
- * There is a deadlock we need to worry about. If the locked directory is
- * in the AIL, it might be blocking up the log. The next inode we lock
- * could be already locked by another thread waiting for log space (e.g
- * a permanent log reservation with a long running transaction (see
- * xfs_itruncate_finish)). To solve this, we must check if the directory
- * is in the ail and use lock_nowait. If we can't lock, we need to
- * drop the inode lock on the directory and try again. xfs_iunlock will
- * potentially push the tail if we were holding up the log.
- */
-STATIC int
-xfs_lock_dir_and_entry(
-	xfs_inode_t	*dp,
-	xfs_inode_t	*ip)	/* inode of entry 'name' */
-{
-	int		attempts;
-	xfs_ino_t	e_inum;
-	xfs_inode_t	*ips[2];
-	xfs_log_item_t	*lp;
-
-#ifdef DEBUG
-	xfs_rm_locks++;
-#endif
-	attempts = 0;
-
-again:
-	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
-
-	e_inum = ip->i_ino;
-
-	xfs_itrace_ref(ip);
-
-	/*
-	 * We want to lock in increasing inum. Since we've already
-	 * acquired the lock on the directory, we may need to release
-	 * if if the inum of the entry turns out to be less.
-	 */
-	if (e_inum > dp->i_ino) {
-		/*
-		 * We are already in the right order, so just
-		 * lock on the inode of the entry.
-		 * We need to use nowait if dp is in the AIL.
-		 */
-
-		lp = (xfs_log_item_t *)dp->i_itemp;
-		if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
-			if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
-				attempts++;
-#ifdef DEBUG
-				xfs_rm_attempts++;
-#endif
-
-				/*
-				 * Unlock dp and try again.
-				 * xfs_iunlock will try to push the tail
-				 * if the inode is in the AIL.
-				 */
-
-				xfs_iunlock(dp, XFS_ILOCK_EXCL);
-
-				if ((attempts % 5) == 0) {
-					delay(1); /* Don't just spin the CPU */
-#ifdef DEBUG
-					xfs_rm_lock_delays++;
-#endif
-				}
-				goto again;
-			}
-		} else {
-			xfs_ilock(ip, XFS_ILOCK_EXCL);
-		}
-	} else if (e_inum < dp->i_ino) {
-		xfs_iunlock(dp, XFS_ILOCK_EXCL);
-
-		ips[0] = ip;
-		ips[1] = dp;
-		xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
-	}
-	/* else	 e_inum == dp->i_ino */
-	/*     This can happen if we're asked to lock /x/..
-	 *     the entry is "..", which is also the parent directory.
-	 */
-
-	return 0;
-}
-
 #ifdef DEBUG
 int xfs_locked_n;
 int xfs_small_retries;
@@ -1946,6 +1841,45 @@ xfs_lock_inodes(
 #endif
 }
 
+void
+xfs_lock_two_inodes(
+	xfs_inode_t		*ip0,
+	xfs_inode_t		*ip1,
+	uint			lock_mode)
+{
+	xfs_inode_t		*temp;
+	int			attempts = 0;
+	xfs_log_item_t		*lp;
+
+	ASSERT(ip0->i_ino != ip1->i_ino);
+
+	if (ip0->i_ino > ip1->i_ino) {
+		temp = ip0;
+		ip0 = ip1;
+		ip1 = temp;
+	}
+
+ again:
+	xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
+
+	/*
+	 * If the first lock we have locked is in the AIL, we must TRY to get
+	 * the second lock. If we can't get it, we must release the first one
+	 * and try again.
+	 */
+	lp = (xfs_log_item_t *)ip0->i_itemp;
+	if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
+		if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
+			xfs_iunlock(ip0, lock_mode);
+			if ((++attempts % 5) == 0)
+				delay(1); /* Don't just spin the CPU */
+			goto again;
+		}
+	} else {
+		xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
+	}
+}
+
 int
 xfs_remove(
 	xfs_inode_t             *dp,
@@ -2018,9 +1952,7 @@ xfs_remove(
 		goto out_trans_cancel;
 	}
 
-	error = xfs_lock_dir_and_entry(dp, ip);
-	if (error)
-		goto out_trans_cancel;
+	xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
 
 	/*
 	 * At this point, we've gotten both the directory and the entry
@@ -2047,9 +1979,6 @@ xfs_remove(
 		}
 	}
 
-	/*
-	 * Entry must exist since we did a lookup in xfs_lock_dir_and_entry.
-	 */
 	XFS_BMAP_INIT(&free_list, &first_block);
 	error = xfs_dir_removename(tp, dp, name, ip->i_ino,
 					&first_block, &free_list, resblks);
@@ -2155,7 +2084,6 @@ xfs_link(
 {
 	xfs_mount_t		*mp = tdp->i_mount;
 	xfs_trans_t		*tp;
-	xfs_inode_t		*ips[2];
 	int			error;
 	xfs_bmap_free_t         free_list;
 	xfs_fsblock_t           first_block;
@@ -2203,15 +2131,7 @@ xfs_link(
 		goto error_return;
 	}
 
-	if (sip->i_ino < tdp->i_ino) {
-		ips[0] = sip;
-		ips[1] = tdp;
-	} else {
-		ips[0] = tdp;
-		ips[1] = sip;
-	}
-
-	xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
+	xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
 
 	/*
 	 * Increment vnode ref counts since xfs_trans_commit &