btrfs: add quota override flag to enable quota override for CAP_SYS_RESOURCE
This patch introduces the quota override flag to btrfs_fs_info, and a
change to quota limit checking code to temporarily allow for quota to be
overridden for processes with CAP_SYS_RESOURCE.
It's useful for administrative programs, such as log rotation, that may
need to temporarily use more disk space in order to free up a greater
amount of overall disk space without yielding more disk space to the
rest of userland.
Eventually, we may want to add the idea of an operator-specific quota,
operator reserved space, or something else to allow for administrative
override, but this is perhaps the simplest solution.
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0334452..aea1b3c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -716,6 +716,8 @@ struct btrfs_delayed_root;
#define BTRFS_FS_BTREE_ERR 11
#define BTRFS_FS_LOG1_ERR 12
#define BTRFS_FS_LOG2_ERR 13
+#define BTRFS_FS_QUOTA_OVERRIDE 14
+
/*
* Indicate that a whole-filesystem exclusive operation is running
* (device replace, resize, device add/delete, balance)