| Message ID | 1530106705-27186-5-git-send-email-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 27.06.2018 16:38, Nikolay Borisov wrote: > In qgroup_rescan_leaf a copy is made of the target leaf by calling > btrfs_clone_extent_buffer. The latter allocates a new buffer and > attaches a new set of pages and copies the content of the source > buffer. The new scratch buffer is only used to iterate it's items, it's > not published anywhere and cannot be accessed by a third party. Hence, > it's not necessary to perform any locking on it whatsoever. Furthermore, > remove the extra extent_buffer_get call since the new buffer is always > allocated with a reference count of 1 which is sufficient here. > No functional changes. > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> I'm going to be sending this patch as part of a larger series so you can ignore it for now. > --- > fs/btrfs/qgroup.c | 7 +------ > 1 file changed, 1 insertion(+), 6 deletions(-) > > diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c > index 1874a6d2e6f5..3b57dc247fa2 100644 > --- a/fs/btrfs/qgroup.c > +++ b/fs/btrfs/qgroup.c > @@ -2647,9 +2647,6 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path, > mutex_unlock(&fs_info->qgroup_rescan_lock); > goto out; > } > - extent_buffer_get(scratch_leaf); > - btrfs_tree_read_lock(scratch_leaf); > - btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK); > slot = path->slots[0]; > btrfs_release_path(path); > mutex_unlock(&fs_info->qgroup_rescan_lock); > @@ -2675,10 +2672,8 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path, > goto out; > } > out: > - if (scratch_leaf) { > - btrfs_tree_read_unlock_blocking(scratch_leaf); > + if (scratch_leaf) > free_extent_buffer(scratch_leaf); > - } > > if (done && !ret) > ret = 1; > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 1874a6d2e6f5..3b57dc247fa2 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2647,9 +2647,6 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path, mutex_unlock(&fs_info->qgroup_rescan_lock); goto out; } - extent_buffer_get(scratch_leaf); - btrfs_tree_read_lock(scratch_leaf); - btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK); slot = path->slots[0]; btrfs_release_path(path); mutex_unlock(&fs_info->qgroup_rescan_lock); @@ -2675,10 +2672,8 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path, goto out; } out: - if (scratch_leaf) { - btrfs_tree_read_unlock_blocking(scratch_leaf); + if (scratch_leaf) free_extent_buffer(scratch_leaf); - } if (done && !ret) ret = 1;
In qgroup_rescan_leaf a copy is made of the target leaf by calling btrfs_clone_extent_buffer. The latter allocates a new buffer and attaches a new set of pages and copies the content of the source buffer. The new scratch buffer is only used to iterate it's items, it's not published anywhere and cannot be accessed by a third party. Hence, it's not necessary to perform any locking on it whatsoever. Furthermore, remove the extra extent_buffer_get call since the new buffer is always allocated with a reference count of 1 which is sufficient here. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- fs/btrfs/qgroup.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-)