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>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2ce9e69ee8f8529fae22c5c11d9e750b7a00cbab..64a199d93d64e144f2ae4ab810fdad145eb9fefc 100644 (file)
--- 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
index 255e85f78313ca7ddb8b28543c82618733c13ef0..8b6340c59bf2d7af4d22dafe9794c044cc37af1b 100644 (file)
--- 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
index efbecc0c5258d2ab730d8dc8dc9f07454e4d98da..4c9e8aabee513d6e24501f3429a8313b35d70b59 100644 (file)
--- 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 */