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| author | Sargun Dhillon <sargun@sargun.me> | 2017-05-11 21:18:03 +0000 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-06-19 18:25:58 +0200 |
| commit | 2723480a0f8fe6c045d23715eaa28f208644f42a (patch) | |
| tree | 5ac1a63ffe81371388ebb7f16c6408b62bc717c8 /fs/btrfs/sysfs.c | |
| parent | f29efe292198b9dbf67fb79ec9ffb5865ca29fb8 (diff) | |
| download | linux-0-day-2723480a0f8fe6c045d23715eaa28f208644f42a.tar.gz linux-0-day-2723480a0f8fe6c045d23715eaa28f208644f42a.tar.xz | |
btrfs: Add quota_override knob into sysfs
This patch adds the read-write attribute quota_override into sysfs.
Any process which has CAP_SYS_RESOURCE can set this flag to on, and
once it is set to true, processes with CAP_SYS_RESOURCE can exceed
the quota.
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>
Diffstat (limited to 'fs/btrfs/sysfs.c')
| -rw-r--r-- | fs/btrfs/sysfs.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 1f157fba89404..c2d5f3580b4cf 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -447,11 +447,52 @@ static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, BTRFS_ATTR(clone_alignment, btrfs_clone_alignment_show); +static ssize_t quota_override_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + int quota_override; + + quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); +} + +static ssize_t quota_override_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + unsigned long knob; + int err; + + if (!fs_info) + return -EPERM; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + err = kstrtoul(buf, 10, &knob); + if (err) + return err; + if (knob > 1) + return -EINVAL; + + if (knob) + set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + else + clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + + return len; +} + +BTRFS_ATTR_RW(quota_override, quota_override_show, quota_override_store); + static const struct attribute *btrfs_attrs[] = { BTRFS_ATTR_PTR(label), BTRFS_ATTR_PTR(nodesize), BTRFS_ATTR_PTR(sectorsize), BTRFS_ATTR_PTR(clone_alignment), + BTRFS_ATTR_PTR(quota_override), NULL, }; |