Merge branch 'master' into for-linus-merged

This merge pulls the XFS master branch into the latest Linus master.
This results in a merge conflict whose best fix is not obvious.
I manually fixed the conflict, in "fs/xfs/xfs_iget.c".

Dave Chinner had done work that resulted in RCU freeing of inodes
separate from what Nick Piggin had done, and their results differed
slightly in xfs_inode_free().  The fix updates Nick's call_rcu()
with the use of VFS_I(), while incorporating needed updates to some
XFS inode fields implemented in Dave's series.  Dave's RCU callback
function has also been removed.

Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 40 insertions, 21 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 8e4a63c4151..d8e6f8cd6f0 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -964,29 +964,48 @@ xfs_release(
 			xfs_flush_pages(ip, 0, -1, XBF_ASYNC, FI_NONE);
 	}
 
-	if (ip->i_d.di_nlink != 0) {
-		if ((((ip->i_d.di_mode & S_IFMT) == S_IFREG) &&
-		     ((ip->i_size > 0) || (VN_CACHED(VFS_I(ip)) > 0 ||
-		       ip->i_delayed_blks > 0)) &&
-		     (ip->i_df.if_flags & XFS_IFEXTENTS))  &&
-		    (!(ip->i_d.di_flags &
-				(XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))) {
+	if (ip->i_d.di_nlink == 0)
+		return 0;
 
-			/*
-			 * If we can't get the iolock just skip truncating
-			 * the blocks past EOF because we could deadlock
-			 * with the mmap_sem otherwise.  We'll get another
-			 * chance to drop them once the last reference to
-			 * the inode is dropped, so we'll never leak blocks
-			 * permanently.
-			 */
-			error = xfs_free_eofblocks(mp, ip,
-						   XFS_FREE_EOF_TRYLOCK);
-			if (error)
-				return error;
-		}
-	}
+	if ((((ip->i_d.di_mode & S_IFMT) == S_IFREG) &&
+	     ((ip->i_size > 0) || (VN_CACHED(VFS_I(ip)) > 0 ||
+	       ip->i_delayed_blks > 0)) &&
+	     (ip->i_df.if_flags & XFS_IFEXTENTS))  &&
+	    (!(ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))) {
 
+		/*
+		 * If we can't get the iolock just skip truncating the blocks
+		 * past EOF because we could deadlock with the mmap_sem
+		 * otherwise.  We'll get another chance to drop them once the
+		 * last reference to the inode is dropped, so we'll never leak
+		 * blocks permanently.
+		 *
+		 * Further, check if the inode is being opened, written and
+		 * closed frequently and we have delayed allocation blocks
+		 * oustanding (e.g. streaming writes from the NFS server),
+		 * truncating the blocks past EOF will cause fragmentation to
+		 * occur.
+		 *
+		 * In this case don't do the truncation, either, but we have to
+		 * be careful how we detect this case. Blocks beyond EOF show
+		 * up as i_delayed_blks even when the inode is clean, so we
+		 * need to truncate them away first before checking for a dirty
+		 * release. Hence on the first dirty close we will still remove
+		 * the speculative allocation, but after that we will leave it
+		 * in place.
+		 */
+		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
+			return 0;
+
+		error = xfs_free_eofblocks(mp, ip,
+					   XFS_FREE_EOF_TRYLOCK);
+		if (error)
+			return error;
+
+		/* delalloc blocks after truncation means it really is dirty */
+		if (ip->i_delayed_blks)
+			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
+	}
 	return 0;
 }