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Diffstat (limited to 'fs/btrfs/scrub.c')
-rw-r--r--fs/btrfs/scrub.c114
1 files changed, 51 insertions, 63 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index eba42e5fd5fd..94cd3a19e9c8 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -33,15 +33,12 @@
* any can be found.
*
* Future enhancements:
- * - To enhance the performance, better read-ahead strategies for the
- * extent-tree can be employed.
* - In case an unrepairable extent is encountered, track which files are
* affected and report them
* - In case of a read error on files with nodatasum, map the file and read
* the extent to trigger a writeback of the good copy
* - track and record media errors, throw out bad devices
* - add a mode to also read unallocated space
- * - make the prefetch cancellable
*/
struct scrub_bio;
@@ -209,7 +206,7 @@ struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
atomic_set(&sdev->in_flight, 0);
atomic_set(&sdev->fixup_cnt, 0);
atomic_set(&sdev->cancel_req, 0);
- sdev->csum_size = btrfs_super_csum_size(&fs_info->super_copy);
+ sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
INIT_LIST_HEAD(&sdev->csum_list);
spin_lock_init(&sdev->list_lock);
@@ -1130,13 +1127,16 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
int slot;
int i;
u64 nstripes;
- int start_stripe;
struct extent_buffer *l;
struct btrfs_key key;
u64 physical;
u64 logical;
u64 generation;
int mirror_num;
+ struct reada_control *reada1;
+ struct reada_control *reada2;
+ struct btrfs_key key_start;
+ struct btrfs_key key_end;
u64 increment = map->stripe_len;
u64 offset;
@@ -1168,81 +1168,67 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
if (!path)
return -ENOMEM;
- path->reada = 2;
path->search_commit_root = 1;
path->skip_locking = 1;
/*
- * find all extents for each stripe and just read them to get
- * them into the page cache
- * FIXME: we can do better. build a more intelligent prefetching
+ * trigger the readahead for extent tree csum tree and wait for
+ * completion. During readahead, the scrub is officially paused
+ * to not hold off transaction commits
*/
logical = base + offset;
- physical = map->stripes[num].physical;
- ret = 0;
- for (i = 0; i < nstripes; ++i) {
- key.objectid = logical;
- key.type = BTRFS_EXTENT_ITEM_KEY;
- key.offset = (u64)0;
-
- ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
- if (ret < 0)
- goto out_noplug;
-
- /*
- * we might miss half an extent here, but that doesn't matter,
- * as it's only the prefetch
- */
- while (1) {
- l = path->nodes[0];
- slot = path->slots[0];
- if (slot >= btrfs_header_nritems(l)) {
- ret = btrfs_next_leaf(root, path);
- if (ret == 0)
- continue;
- if (ret < 0)
- goto out_noplug;
- break;
- }
- btrfs_item_key_to_cpu(l, &key, slot);
+ wait_event(sdev->list_wait,
+ atomic_read(&sdev->in_flight) == 0);
+ atomic_inc(&fs_info->scrubs_paused);
+ wake_up(&fs_info->scrub_pause_wait);
- if (key.objectid >= logical + map->stripe_len)
- break;
+ /* FIXME it might be better to start readahead at commit root */
+ key_start.objectid = logical;
+ key_start.type = BTRFS_EXTENT_ITEM_KEY;
+ key_start.offset = (u64)0;
+ key_end.objectid = base + offset + nstripes * increment;
+ key_end.type = BTRFS_EXTENT_ITEM_KEY;
+ key_end.offset = (u64)0;
+ reada1 = btrfs_reada_add(root, &key_start, &key_end);
+
+ key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key_start.type = BTRFS_EXTENT_CSUM_KEY;
+ key_start.offset = logical;
+ key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key_end.type = BTRFS_EXTENT_CSUM_KEY;
+ key_end.offset = base + offset + nstripes * increment;
+ reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
+
+ if (!IS_ERR(reada1))
+ btrfs_reada_wait(reada1);
+ if (!IS_ERR(reada2))
+ btrfs_reada_wait(reada2);
- path->slots[0]++;
- }
- btrfs_release_path(path);
- logical += increment;
- physical += map->stripe_len;
- cond_resched();
+ mutex_lock(&fs_info->scrub_lock);
+ while (atomic_read(&fs_info->scrub_pause_req)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrub_pause_req) == 0);
+ mutex_lock(&fs_info->scrub_lock);
}
+ atomic_dec(&fs_info->scrubs_paused);
+ mutex_unlock(&fs_info->scrub_lock);
+ wake_up(&fs_info->scrub_pause_wait);
/*
* collect all data csums for the stripe to avoid seeking during
* the scrub. This might currently (crc32) end up to be about 1MB
*/
- start_stripe = 0;
blk_start_plug(&plug);
-again:
- logical = base + offset + start_stripe * increment;
- for (i = start_stripe; i < nstripes; ++i) {
- ret = btrfs_lookup_csums_range(csum_root, logical,
- logical + map->stripe_len - 1,
- &sdev->csum_list, 1);
- if (ret)
- goto out;
- logical += increment;
- cond_resched();
- }
/*
* now find all extents for each stripe and scrub them
*/
- logical = base + offset + start_stripe * increment;
- physical = map->stripes[num].physical + start_stripe * map->stripe_len;
+ logical = base + offset;
+ physical = map->stripes[num].physical;
ret = 0;
- for (i = start_stripe; i < nstripes; ++i) {
+ for (i = 0; i < nstripes; ++i) {
/*
* canceled?
*/
@@ -1271,11 +1257,14 @@ again:
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
wake_up(&fs_info->scrub_pause_wait);
- scrub_free_csums(sdev);
- start_stripe = i;
- goto again;
}
+ ret = btrfs_lookup_csums_range(csum_root, logical,
+ logical + map->stripe_len - 1,
+ &sdev->csum_list, 1);
+ if (ret)
+ goto out;
+
key.objectid = logical;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = (u64)0;
@@ -1371,7 +1360,6 @@ next:
out:
blk_finish_plug(&plug);
-out_noplug:
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}