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path: root/fs/btrfs/free-space-cache.c
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Diffstat (limited to 'fs/btrfs/free-space-cache.c')
-rw-r--r--fs/btrfs/free-space-cache.c63
1 files changed, 56 insertions, 7 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 3283da419200..669809d5214e 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -752,6 +752,14 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
goto free_cache;
}
+ /*
+ * Sync discard ensures that the free space cache is always
+ * trimmed. So when reading this in, the state should reflect
+ * that.
+ */
+ if (btrfs_test_opt(fs_info, DISCARD_SYNC))
+ e->trim_state = BTRFS_TRIM_STATE_TRIMMED;
+
if (!e->bytes) {
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
@@ -2161,6 +2169,22 @@ out:
return ret;
}
+/*
+ * Free space merging rules:
+ * 1) Merge trimmed areas together
+ * 2) Let untrimmed areas coalesce with trimmed areas
+ * 3) Always pull neighboring regions from bitmaps
+ *
+ * The above rules are for when we merge free space based on btrfs_trim_state.
+ * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
+ * same reason: to promote larger extent regions which makes life easier for
+ * find_free_extent(). Rule 2 enables coalescing based on the common path
+ * being returning free space from btrfs_finish_extent_commit(). So when free
+ * space is trimmed, it will prevent aggregating trimmed new region and
+ * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
+ * and provide find_free_extent() with the largest extents possible hoping for
+ * the reuse path.
+ */
static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, bool update_stat)
{
@@ -2169,6 +2193,7 @@ static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
bool merged = false;
u64 offset = info->offset;
u64 bytes = info->bytes;
+ const bool is_trimmed = btrfs_free_space_trimmed(info);
/*
* first we want to see if there is free space adjacent to the range we
@@ -2182,7 +2207,9 @@ static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
else
left_info = tree_search_offset(ctl, offset - 1, 0, 0);
- if (right_info && !right_info->bitmap) {
+ /* See try_merge_free_space() comment. */
+ if (right_info && !right_info->bitmap &&
+ (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
if (update_stat)
unlink_free_space(ctl, right_info);
else
@@ -2192,8 +2219,10 @@ static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
merged = true;
}
+ /* See try_merge_free_space() comment. */
if (left_info && !left_info->bitmap &&
- left_info->offset + left_info->bytes == offset) {
+ left_info->offset + left_info->bytes == offset &&
+ (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
if (update_stat)
unlink_free_space(ctl, left_info);
else
@@ -2229,6 +2258,10 @@ static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
bytes = (j - i) * ctl->unit;
info->bytes += bytes;
+ /* See try_merge_free_space() comment. */
+ if (!btrfs_free_space_trimmed(bitmap))
+ info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
+
if (update_stat)
bitmap_clear_bits(ctl, bitmap, end, bytes);
else
@@ -2282,6 +2315,10 @@ static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
info->offset -= bytes;
info->bytes += bytes;
+ /* See try_merge_free_space() comment. */
+ if (!btrfs_free_space_trimmed(bitmap))
+ info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
+
if (update_stat)
bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
else
@@ -2331,7 +2368,8 @@ static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
struct btrfs_free_space_ctl *ctl,
- u64 offset, u64 bytes)
+ u64 offset, u64 bytes,
+ enum btrfs_trim_state trim_state)
{
struct btrfs_free_space *info;
int ret = 0;
@@ -2342,6 +2380,7 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
info->offset = offset;
info->bytes = bytes;
+ info->trim_state = trim_state;
RB_CLEAR_NODE(&info->offset_index);
spin_lock(&ctl->tree_lock);
@@ -2387,9 +2426,14 @@ out:
int btrfs_add_free_space(struct btrfs_block_group *block_group,
u64 bytenr, u64 size)
{
+ enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
+
+ if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
+ trim_state = BTRFS_TRIM_STATE_TRIMMED;
+
return __btrfs_add_free_space(block_group->fs_info,
block_group->free_space_ctl,
- bytenr, size);
+ bytenr, size, trim_state);
}
int btrfs_remove_free_space(struct btrfs_block_group *block_group,
@@ -2464,8 +2508,10 @@ again:
}
spin_unlock(&ctl->tree_lock);
- ret = btrfs_add_free_space(block_group, offset + bytes,
- old_end - (offset + bytes));
+ ret = __btrfs_add_free_space(block_group->fs_info, ctl,
+ offset + bytes,
+ old_end - (offset + bytes),
+ info->trim_state);
WARN_ON(ret);
goto out;
}
@@ -2634,6 +2680,7 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
u64 ret = 0;
u64 align_gap = 0;
u64 align_gap_len = 0;
+ enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
spin_lock(&ctl->tree_lock);
entry = find_free_space(ctl, &offset, &bytes_search,
@@ -2650,6 +2697,7 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
unlink_free_space(ctl, entry);
align_gap_len = offset - entry->offset;
align_gap = entry->offset;
+ align_gap_trim_state = entry->trim_state;
entry->offset = offset + bytes;
WARN_ON(entry->bytes < bytes + align_gap_len);
@@ -2665,7 +2713,8 @@ out:
if (align_gap_len)
__btrfs_add_free_space(block_group->fs_info, ctl,
- align_gap, align_gap_len);
+ align_gap, align_gap_len,
+ align_gap_trim_state);
return ret;
}
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-29 00:45:16 +0300