btrfs: factor out btrfs_return_free_space()

Factor out a part of unpin_extent_range() that returns space back to the space info, prioritizing global block reserve. Also, move the "len" variable into the loop to clarify we don't need to carry it beyond an iteration. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
norov · Jan 13, 2025 · 3704db1 · 3704db1
1 parent bfcf6d0
commit 3704db1
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Showing 3 changed files with 34 additions and 21 deletions.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
@@ -2700,15 +2700,15 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 {
 	struct btrfs_block_group *cache = NULL;
 	struct btrfs_space_info *space_info;
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
 	struct btrfs_free_cluster *cluster = NULL;
-	u64 len;
 	u64 total_unpinned = 0;
 	u64 empty_cluster = 0;
 	bool readonly;
 	int ret = 0;
 
 	while (start <= end) {
+		u64 len;
+
 		readonly = false;
 		if (!cache ||
 		    start >= cache->start + cache->length) {
@@ -2766,25 +2766,8 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 			readonly = true;
 		}
 		spin_unlock(&cache->lock);
-		if (!readonly && return_free_space &&
-		    global_rsv->space_info == space_info) {
-			spin_lock(&global_rsv->lock);
-			if (!global_rsv->full) {
-				u64 to_add = min(len, global_rsv->size -
-						      global_rsv->reserved);
-
-				global_rsv->reserved += to_add;
-				btrfs_space_info_update_bytes_may_use(fs_info,
-						space_info, to_add);
-				if (global_rsv->reserved >= global_rsv->size)
-					global_rsv->full = 1;
-				len -= to_add;
-			}
-			spin_unlock(&global_rsv->lock);
-		}
-		/* Add to any tickets we may have */
-		if (!readonly && return_free_space && len)
-			btrfs_try_granting_tickets(fs_info, space_info);
+		if (!readonly && return_free_space)
+			btrfs_return_free_space(space_info, len);
 		spin_unlock(&space_info->lock);
 	}
 

diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
@@ -2082,3 +2082,32 @@ void btrfs_reclaim_sweep(const struct btrfs_fs_info *fs_info)
 			do_reclaim_sweep(space_info, raid);
 	}
 }
+
+void btrfs_return_free_space(struct btrfs_space_info *space_info, u64 len)
+{
+	struct btrfs_fs_info *fs_info = space_info->fs_info;
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+
+	lockdep_assert_held(&space_info->lock);
+
+	/* Prioritize the global reservation to receive the freed space. */
+	if (global_rsv->space_info != space_info)
+		goto grant;
+
+	spin_lock(&global_rsv->lock);
+	if (!global_rsv->full) {
+		u64 to_add = min(len, global_rsv->size - global_rsv->reserved);
+
+		global_rsv->reserved += to_add;
+		btrfs_space_info_update_bytes_may_use(fs_info, space_info, to_add);
+		if (global_rsv->reserved >= global_rsv->size)
+			global_rsv->full = 1;
+		len -= to_add;
+	}
+	spin_unlock(&global_rsv->lock);
+
+grant:
+	/* Add to any tickets we may have. */
+	if (len)
+		btrfs_try_granting_tickets(fs_info, space_info);
+}
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
@@ -295,5 +295,6 @@ void btrfs_set_periodic_reclaim_ready(struct btrfs_space_info *space_info, bool
 bool btrfs_should_periodic_reclaim(struct btrfs_space_info *space_info);
 int btrfs_calc_reclaim_threshold(const struct btrfs_space_info *space_info);
 void btrfs_reclaim_sweep(const struct btrfs_fs_info *fs_info);
+void btrfs_return_free_space(struct btrfs_space_info *space_info, u64 len);
 
 #endif /* BTRFS_SPACE_INFO_H */