Callers of btrfs_discard_extent() should check if we are mounted with -o
discard,
as we want to make fitrim to work even the fs is not mounted with -o discard.
Also we should use REQ_DISCARD to map the free extent to get a full mapping,
last we only return errors if
1. the error is not a EOPNOTSUPP
2. no device supports discard
Signed-off-by: Li Dongyang <lidongy...@novell.com>
---
fs/btrfs/ctree.h | 2 +-
fs/btrfs/disk-io.c | 5 ++++-
fs/btrfs/extent-tree.c | 45 ++++++++++++++++++++++++++-------------------
3 files changed, 31 insertions(+), 21 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2c84551..94bb772 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2229,7 +2229,7 @@ u64 btrfs_account_ro_block_groups_free_space(struct
btrfs_space_info *sinfo);
int btrfs_error_unpin_extent_range(struct btrfs_root *root,
u64 start, u64 end);
int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes);
+ u64 num_bytes, u64 *actual_bytes);
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 100b07f..98b60b0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2947,7 +2947,10 @@ static int btrfs_destroy_pinned_extent(struct btrfs_root
*root,
break;
/* opt_discard */
- ret = btrfs_error_discard_extent(root, start, end + 1 - start);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_error_discard_extent(root, start,
+ end + 1 - start,
+ NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
btrfs_error_unpin_extent_range(root, start, end);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index caa4254..10e542a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1738,40 +1738,44 @@ static int remove_extent_backref(struct
btrfs_trans_handle *trans,
return ret;
}
-static void btrfs_issue_discard(struct block_device *bdev,
+static int btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
- blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
+ return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes)
+ u64 num_bytes, u64 *actual_bytes)
{
int ret;
- u64 map_length = num_bytes;
+ u64 discarded_bytes = 0;
struct btrfs_multi_bio *multi = NULL;
- if (!btrfs_test_opt(root, DISCARD))
- return 0;
-
/* 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);
+ ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
+ bytenr, &num_bytes, &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++) {
- btrfs_issue_discard(stripe->dev->bdev,
- stripe->physical,
- map_length);
+ ret = btrfs_issue_discard(stripe->dev->bdev,
+ stripe->physical,
+ stripe->length);
+ if (!ret)
+ discarded_bytes += stripe->length;
+ else if (ret != -EOPNOTSUPP)
+ break;
}
kfree(multi);
}
+ if (discarded_bytes && ret == -EOPNOTSUPP)
+ ret = 0;
+
+ if (actual_bytes)
+ *actual_bytes = discarded_bytes;
+
return ret;
}
@@ -4361,7 +4365,9 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle
*trans,
if (ret)
break;
- ret = btrfs_discard_extent(root, start, end + 1 - start);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start,
+ end + 1 - start, NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
unpin_extent_range(root, start, end);
@@ -5410,7 +5416,8 @@ int btrfs_free_reserved_extent(struct btrfs_root *root,
u64 start, u64 len)
return -ENOSPC;
}
- ret = btrfs_discard_extent(root, start, len);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start, len, NULL);
btrfs_add_free_space(cache, start, len);
btrfs_update_reserved_bytes(cache, len, 0, 1);
@@ -8728,7 +8735,7 @@ int btrfs_error_unpin_extent_range(struct btrfs_root
*root, u64 start, u64 end)
}
int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
- u64 num_bytes)
+ u64 num_bytes, u64 *actual_bytes)
{
- return btrfs_discard_extent(root, bytenr, num_bytes);
+ return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
}
--
1.7.4.1
--
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