GFS2: Issue discards in 512b sectors

This patch changes GFS2's discard issuing code so that it calls
function sb_issue_discard rather than blkdev_issue_discard. The
code was calling blkdev_issue_discard and specifying the correct
sector offset and sector size, but blkdev_issue_discard expects
these values to be in terms of 512 byte sectors, even if the native
sector size for the device is different. Calling sb_issue_discard
with the BLOCK size instead ensures the correct block-to-512b-sector
translation. I verified that "minlen" is specified in blocks, so
comparing it to a number of blocks is correct.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 13 insertions, 17 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 70d1cd0b5f3b..5a51265a4341 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1181,12 +1181,9 @@ int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
                              const struct gfs2_bitmap *bi, unsigned minlen, u64 *ptrimmed)
 {
         struct super_block *sb = sdp->sd_vfs;
-        struct block_device *bdev = sb->s_bdev;
-        const unsigned int sects_per_blk = sdp->sd_sb.sb_bsize /
-                                           bdev_logical_block_size(sb->s_bdev);
         u64 blk;
         sector_t start = 0;
-        sector_t nr_sects = 0;
+        sector_t nr_blks = 0;
         int rv;
         unsigned int x;
         u32 trimmed = 0;
@@ -1206,35 +1203,34 @@ int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
                 if (diff == 0)
                         continue;
                 blk = offset + ((bi->bi_start + x) * GFS2_NBBY);
-                blk *= sects_per_blk; /* convert to sectors */
                 while(diff) {
                         if (diff & 1) {
-                                if (nr_sects == 0)
+                                if (nr_blks == 0)
                                         goto start_new_extent;
-                                if ((start + nr_sects) != blk) {
-                                        if (nr_sects >= minlen) {
-                                                rv = blkdev_issue_discard(bdev,
-                                                        start, nr_sects,
+                                if ((start + nr_blks) != blk) {
+                                        if (nr_blks >= minlen) {
+                                                rv = sb_issue_discard(sb,
+                                                        start, nr_blks,
                                                         GFP_NOFS, 0);
                                                 if (rv)
                                                         goto fail;
-                                                trimmed += nr_sects;
+                                                trimmed += nr_blks;
                                         }
-                                        nr_sects = 0;
+                                        nr_blks = 0;
 start_new_extent:
                                         start = blk;
                                 }
-                                nr_sects += sects_per_blk;
+                                nr_blks++;
                         }
                         diff >>= 2;
-                        blk += sects_per_blk;
+                        blk++;
                 }
         }
-        if (nr_sects >= minlen) {
-                rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS, 0);
+        if (nr_blks >= minlen) {
+                rv = sb_issue_discard(sb, start, nr_blks, GFP_NOFS, 0);
                 if (rv)
                         goto fail;
-                trimmed += nr_sects;
+                trimmed += nr_blks;
         }
         if (ptrimmed)
                 *ptrimmed = trimmed;