diff options
| author | Jeff Mahoney <jeffm@suse.com> | 2013-11-15 15:33:55 -0500 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-01-28 13:19:23 -0800 |
| commit | 2eaa055fab4e3127c9f572fda1b710cbb2acdf1c (patch) | |
| tree | 43ec0254e30315288d03196054ff3fff534ed06c /fs/btrfs/ctree.h | |
| parent | 9e5ac13acbb9e806a54f131432501bf462248c35 (diff) | |
btrfs: add ioctls to query/change feature bits online
There are some feature bits that require no offline setup and can
be enabled online. I've only reviewed extended irefs, but there will
probably be more.
We introduce three new ioctls:
- BTRFS_IOC_GET_SUPPORTED_FEATURES: query the kernel for supported features.
- BTRFS_IOC_GET_FEATURES: query the kernel for enabled features on a per-fs
basis, as well as querying for which features are changeable with mounted.
- BTRFS_IOC_SET_FEATURES: change features on a per-fs basis.
We introduce two new masks per feature set (_SAFE_SET and _SAFE_CLEAR) that
allow us to define which features are safe to change at runtime.
The failure modes for BTRFS_IOC_SET_FEATURES are as follows:
- Enabling a completely unsupported feature: warns and returns -ENOTSUPP
- Enabling a feature that can only be done offline: warns and returns -EPERM
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/ctree.h')
| -rw-r--r-- | fs/btrfs/ctree.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1aafccda05d..498452ebfd3 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -524,7 +524,12 @@ struct btrfs_super_block { #define BTRFS_FEATURE_INCOMPAT_NO_HOLES (1ULL << 9) #define BTRFS_FEATURE_COMPAT_SUPP 0ULL +#define BTRFS_FEATURE_COMPAT_SAFE_SET 0ULL +#define BTRFS_FEATURE_COMPAT_SAFE_CLEAR 0ULL #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL +#define BTRFS_FEATURE_COMPAT_RO_SAFE_SET 0ULL +#define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR 0ULL + #define BTRFS_FEATURE_INCOMPAT_SUPP \ (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \ @@ -536,6 +541,10 @@ struct btrfs_super_block { BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA | \ BTRFS_FEATURE_INCOMPAT_NO_HOLES) +#define BTRFS_FEATURE_INCOMPAT_SAFE_SET \ + (BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF) +#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL + /* * A leaf is full of items. offset and size tell us where to find * the item in the leaf (relative to the start of the data area) |