nilfs2: issue discard request after cleaning segments
This adds a function to send discard requests for given array of
segment numbers, and calls the function when garbage collection
succeeded.
Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 6241e17..92733d5 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -646,6 +646,44 @@
goto out;
}
+int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
+ size_t nsegs)
+{
+ sector_t seg_start, seg_end;
+ sector_t start = 0, nblocks = 0;
+ unsigned int sects_per_block;
+ __u64 *sn;
+ int ret = 0;
+
+ sects_per_block = (1 << nilfs->ns_blocksize_bits) /
+ bdev_logical_block_size(nilfs->ns_bdev);
+ for (sn = segnump; sn < segnump + nsegs; sn++) {
+ nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
+
+ if (!nblocks) {
+ start = seg_start;
+ nblocks = seg_end - seg_start + 1;
+ } else if (start + nblocks == seg_start) {
+ nblocks += seg_end - seg_start + 1;
+ } else {
+ ret = blkdev_issue_discard(nilfs->ns_bdev,
+ start * sects_per_block,
+ nblocks * sects_per_block,
+ GFP_NOFS,
+ DISCARD_FL_BARRIER);
+ if (ret < 0)
+ return ret;
+ nblocks = 0;
+ }
+ }
+ if (nblocks)
+ ret = blkdev_issue_discard(nilfs->ns_bdev,
+ start * sects_per_block,
+ nblocks * sects_per_block,
+ GFP_NOFS, DISCARD_FL_BARRIER);
+ return ret;
+}
+
int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
{
struct inode *dat = nilfs_dat_inode(nilfs);
