From f29efe292198b9dbf67fb79ec9ffb5865ca29fb8 Mon Sep 17 00:00:00 2001 From: Sargun Dhillon <sargun@sargun.me> Date: Thu, 11 May 2017 21:17:33 +0000 Subject: 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> --- fs/btrfs/qgroup.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/btrfs/qgroup.c') diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index deffbeb..458fec0 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2338,6 +2338,11 @@ static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce) if (num_bytes == 0) return 0; + + if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) && + capable(CAP_SYS_RESOURCE)) + enforce = false; + retry: spin_lock(&fs_info->qgroup_lock); quota_root = fs_info->quota_root; -- cgit v1.1