1 files changed, 49 insertions, 3 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index de70e52caf3a..a68e91bcef3d 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: