Btrfs: Discard sector data in __free_extent()
Date: Tue, 12 Aug 2008 14:13:26 +0100
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fff219e..e63b3b4 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -18,6 +18,7 @@
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
+#include <linux/blkdev.h>
#include "hash.h"
#include "crc32c.h"
#include "ctree.h"
@@ -1716,6 +1717,10 @@
if (refs == 0) {
u64 super_used;
u64 root_used;
+#ifdef BIO_RW_DISCARD
+ u64 map_length = num_bytes;
+ struct btrfs_multi_bio *multi = NULL;
+#endif
if (pin) {
ret = pin_down_bytes(root, bytenr, num_bytes, 0);
@@ -1743,6 +1748,26 @@
ret = update_block_group(trans, root, bytenr, num_bytes, 0,
mark_free);
BUG_ON(ret);
+
+#ifdef BIO_RW_DISCARD
+ /* Tell the block device(s) that the sectors can be discarded */
+ ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+ bytenr, &map_length, &multi, 0);
+ if (!ret) {
+ struct btrfs_bio_stripe *stripe = multi->stripes;
+ int i;
+
+ if (map_length > num_bytes)
+ map_length = num_bytes;
+
+ for (i = 0; i < multi->num_stripes; i++, stripe++) {
+ blkdev_issue_discard(stripe->dev->bdev,
+ stripe->physical >> 9,
+ map_length >> 9);
+ }
+ kfree(multi);
+ }
+#endif
}
btrfs_free_path(path);
finish_current_insert(trans, extent_root);