1 files changed, 49 insertions, 3 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index de70e52..a68e91b 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -991,6 +991,41 @@ unlock:
 	return err;
 }
 
+/**
+ * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files
+ * @inode: The inode being truncated
+ * @oldsize: The original (larger) size
+ * @newsize: The new smaller size
+ *
+ * With jdata files, we have to journal a revoke for each block which is
+ * truncated. As a result, we need to split this into separate transactions
+ * if the number of pages being truncated gets too large.
+ */
+
+#define GFS2_JTRUNC_REVOKES 8192
+
+static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
+	u64 chunk;
+	int error;
+
+	while (oldsize != newsize) {
+		chunk = oldsize - newsize;
+		if (chunk > max_chunk)
+			chunk = max_chunk;
+		truncate_pagecache(inode, oldsize, oldsize - chunk);
+		oldsize -= chunk;
+		gfs2_trans_end(sdp);
+		error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
 static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);
@@ -1000,8 +1035,10 @@ static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize)
 	int journaled = gfs2_is_jdata(ip);
 	int error;
 
-	error = gfs2_trans_begin(sdp,
-				 RES_DINODE + (journaled ? RES_JDATA : 0), 0);
+	if (journaled)
+		error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES);
+	else
+		error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 	if (error)
 		return error;
 
@@ -1026,7 +1063,16 @@ static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize)
 	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 	gfs2_dinode_out(ip, dibh->b_data);
 
-	truncate_pagecache(inode, oldsize, newsize);
+	if (journaled)
+		error = gfs2_journaled_truncate(inode, oldsize, newsize);
+	else
+		truncate_pagecache(inode, oldsize, newsize);
+
+	if (error) {
+		brelse(dibh);
+		return error;
+	}
+
 out_brelse:
 	brelse(dibh);
 out: