This patch will extract unclsutered extent allocation code into
find_free_extent_unclustered().
And this helper function will use return value to indicate what to do
next.
This should make find_free_extent() a little easier to read.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
[Update merge conflict with fb5c39d7a887 ("btrfs: don't use ctl->free_space for max_extent_size")]
---
fs/btrfs/extent-tree.c | 114 ++++++++++++++++++++++++-----------------
1 file changed, 68 insertions(+), 46 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7b0c93cf280e..2c9f00cb8f26 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7400,6 +7400,69 @@ static int find_free_extent_clustered(struct btrfs_block_group_cache *bg,
return 1;
}
+/*
+ * Return >0 to inform caller that we find nothing
+ * Return 0 when we found an free extent and set ffe_ctrl->found_offset
+ * Return -EAGAIN to inform caller that we need to re-search this block group
+ */
+static int find_free_extent_unclustered(struct btrfs_block_group_cache *bg,
+ struct btrfs_free_cluster *last_ptr,
+ struct find_free_extent_ctl *ffe_ctl)
+{
+ u64 offset;
+
+ /*
+ * We are doing an unclustered alloc, set the fragmented flag so we
+ * don't bother trying to setup a cluster again until we get more space.
+ */
+ if (unlikely(last_ptr)) {
+ spin_lock(&last_ptr->lock);
+ last_ptr->fragmented = 1;
+ spin_unlock(&last_ptr->lock);
+ }
+ if (ffe_ctl->cached) {
+ struct btrfs_free_space_ctl *free_space_ctl;
+
+ free_space_ctl = bg->free_space_ctl;
+ spin_lock(&free_space_ctl->tree_lock);
+ if (free_space_ctl->free_space <
+ ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
+ ffe_ctl->empty_size) {
+ ffe_ctl->total_free_space = max_t(u64,
+ ffe_ctl->total_free_space,
+ free_space_ctl->free_space);
+ spin_unlock(&free_space_ctl->tree_lock);
+ return 1;
+ }
+ spin_unlock(&free_space_ctl->tree_lock);
+ }
+
+ offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start,
+ ffe_ctl->num_bytes, ffe_ctl->empty_size,
+ &ffe_ctl->max_extent_size);
+
+ /*
+ * If we didn't find a chunk, and we haven't failed on this block group
+ * before, and this block group is in the middle of caching and we are
+ * ok with waiting, then go ahead and wait for progress to be made, and
+ * set @retry_unclustered to true.
+ *
+ * If @retry_unclustered is true then we've already waited on this block
+ * group once and should move on to the next block group.
+ */
+ if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached &&
+ ffe_ctl->loop > LOOP_CACHING_NOWAIT) {
+ wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
+ ffe_ctl->empty_size);
+ ffe_ctl->retry_unclustered = true;
+ return -EAGAIN;
+ } else if (!offset) {
+ return 1;
+ }
+ ffe_ctl->found_offset = offset;
+ return 0;
+}
+
/*
* walks the btree of allocated extents and find a hole of a given size.
* The key ins is changed to record the hole:
@@ -7602,54 +7665,13 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info,
/* ret == -ENOENT case falls through */
}
- /*
- * We are doing an unclustered alloc, set the fragmented flag so
- * we don't bother trying to setup a cluster again until we get
- * more space.
- */
- if (unlikely(last_ptr)) {
- spin_lock(&last_ptr->lock);
- last_ptr->fragmented = 1;
- spin_unlock(&last_ptr->lock);
- }
- if (ffe_ctl.cached) {
- struct btrfs_free_space_ctl *ctl =
- block_group->free_space_ctl;
-
- spin_lock(&ctl->tree_lock);
- if (ctl->free_space <
- num_bytes + ffe_ctl.empty_cluster + empty_size) {
- ffe_ctl.total_free_space = max(ctl->free_space,
- ffe_ctl.total_free_space);
- spin_unlock(&ctl->tree_lock);
- goto loop;
- }
- spin_unlock(&ctl->tree_lock);
- }
-
- ffe_ctl.found_offset = btrfs_find_space_for_alloc(block_group,
- ffe_ctl.search_start, num_bytes, empty_size,
- &ffe_ctl.max_extent_size);
- /*
- * If we didn't find a chunk, and we haven't failed on this
- * block group before, and this block group is in the middle of
- * caching and we are ok with waiting, then go ahead and wait
- * for progress to be made, and set ffe_ctl.retry_unclustered to
- * true.
- *
- * If ffe_ctl.retry_unclustered is true then we've already
- * waited on this block group once and should move on to the
- * next block group.
- */
- if (!ffe_ctl.found_offset && !ffe_ctl.retry_unclustered &&
- !ffe_ctl.cached && ffe_ctl.loop > LOOP_CACHING_NOWAIT) {
- wait_block_group_cache_progress(block_group,
- num_bytes + empty_size);
- ffe_ctl.retry_unclustered = true;
+ ret = find_free_extent_unclustered(block_group, last_ptr,
+ &ffe_ctl);
+ if (ret == -EAGAIN)
goto have_block_group;
- } else if (!ffe_ctl.found_offset) {
+ else if (ret > 0)
goto loop;
- }
+ /* ret == 0 case falls through */
checks:
ffe_ctl.search_start = round_up(ffe_ctl.found_offset,
fs_info->stripesize);
--
2.19.1
