ocfs2: fstrim: Fix start offset of first cluster group during fstrim

[sfrench/cifs-2.6.git] / fs / ocfs2 / alloc.c

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index a177eae3aa1ad593adc62349d6e734cc026717b4..addd7c5f2d3e522a7a65bd51b0164ef705402605 100644 (file)
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -7304,13 +7304,24 @@ out:
 
 static int ocfs2_trim_extent(struct super_block *sb,
                             struct ocfs2_group_desc *gd,
-                            u32 start, u32 count)
+                            u64 group, u32 start, u32 count)
 {
        u64 discard, bcount;
+       struct ocfs2_super *osb = OCFS2_SB(sb);
 
        bcount = ocfs2_clusters_to_blocks(sb, count);
-       discard = le64_to_cpu(gd->bg_blkno) +
-                       ocfs2_clusters_to_blocks(sb, start);
+       discard = ocfs2_clusters_to_blocks(sb, start);
+
+       /*
+        * For the first cluster group, the gd->bg_blkno is not at the start
+        * of the group, but at an offset from the start. If we add it while
+        * calculating discard for first group, we will wrongly start fstrim a
+        * few blocks after the desried start block and the range can cross
+        * over into the next cluster group. So, add it only if this is not
+        * the first cluster group.
+        */
+       if (group != osb->first_cluster_group_blkno)
+               discard += le64_to_cpu(gd->bg_blkno);
 
        trace_ocfs2_trim_extent(sb, (unsigned long long)discard, bcount);
 
@@ -7318,7 +7329,7 @@ static int ocfs2_trim_extent(struct super_block *sb,
 }
 
 static int ocfs2_trim_group(struct super_block *sb,
-                           struct ocfs2_group_desc *gd,
+                           struct ocfs2_group_desc *gd, u64 group,
                            u32 start, u32 max, u32 minbits)
 {
        int ret = 0, count = 0, next;
@@ -7337,7 +7348,7 @@ static int ocfs2_trim_group(struct super_block *sb,
                next = ocfs2_find_next_bit(bitmap, max, start);
 
                if ((next - start) >= minbits) {
-                       ret = ocfs2_trim_extent(sb, gd,
+                       ret = ocfs2_trim_extent(sb, gd, group,
                                                start, next - start);
                        if (ret < 0) {
                                mlog_errno(ret);
@@ -7435,7 +7446,8 @@ int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
                }
 
                gd = (struct ocfs2_group_desc *)gd_bh->b_data;
-               cnt = ocfs2_trim_group(sb, gd, first_bit, last_bit, minlen);
+               cnt = ocfs2_trim_group(sb, gd, group,
+                                      first_bit, last_bit, minlen);
                brelse(gd_bh);
                gd_bh = NULL;
                if (cnt < 0) {