This patch implements functionality for following ioctls:
BTRFS_IOC_QUOTA_CTL - Enabling/Disabling quota support
Enable or disable quota support for a btrfs filesystem. Quota
support is enabled or disabled using the ioctls third argument
which represents a pointer to a following type:
struct btrfs_ioctl_quota_ctl_args {
__u64 cmd;
__u64 status;
};
Before calling this ioctl, the 'cmd' field should be filled
with one of the values 'BTRFS_QUOTA_CTL_ENABLE' (enabling quota)
'BTRFS_QUOTA_CTL_DISABLE' (disabling quota).
BTRFS_IOC_QGROUP_CREATE - Creating/Removing a subvolume quota group
Create or remove a subvolume quota group. The subvolume quota
group is created or removed using the ioctl's third argument which
represents a pointer to a following type:
struct btrfs_ioctl_qgroup_create_args {
__u64 create;
__u64 qgroupid;
};
Before calling this ioctl, the 'create' field should be filled
with the aproppriate value depending on if the user wants to
create or remove a quota group (0 for removing, everything else
for creating). Also, the 'qgroupid' field should be filled with
the value for the quota group id that is to be created.
BTRFS_IOC_QGROUP_ASSIGN - Asigning or removing a quota group as child group
Asign or remove a quota group as child quota group of another
group in the btrfs filesystem. The asignment is done using the
ioctl's third argument which represents a pointert to a following type:
struct btrfs_ioctl_qgroup_assign_args {
__u64 assign;
__u64 src;
__u64 dst;
};
Before calling this ioctl, the 'assign' field should be filled with
the aproppriate value depending on if the user wants to asign or remove
a quota group as a child quota group of another group (0 for removing,
everythin else for asigning). Also, the 'src' and 'dst' fields should
be filled with the aproppriate quota group id values depending on which
quota group needs to asigned or removed as child quota group of another
group ('src' gets asigned or removed as child group of 'dst').
BTRFS_IOC_QGROUP_LIMIT - Limiting the size of a quota group
Limit the size of a quota group. The size of the quota group is limited
with the ioctls third argument which represents a pointer to a following
type:
struct btrfs_ioctl_qgroup_limit_args {
__u64 qgroupid;
struct btrfs_qgroup_limit lim;
};
Before calling this ioctl, the 'qgroup' id field should be filled with
aproppriate value of the quota group id for which the size is to be
limited. The second field is of following type:
struct btrfs_qgroup_limit {
__u64 flags;
__u64 max_rfer;
__u64 max_excl;
__u64 rsv_rfer;
__u64 rsv_excl;
};
The 'max_rfer' field should be filled with the size to which the quota
group should be limited. The 'flags' field can be used for passing
additional options and can have values which can be found on:
https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/btrfs.h#L67
BTRFS_IOC_QUOTA_RESCAN_STATUS - Checking status of running rescan operation
Check status of a running rescan operation. The status is checked using
the ioctl's third argument which represents a pointer to a following type:
struct btrfs_ioctl_quota_rescan_args {
__u64 flags;
__u64 progress;
__u64 reserved[6];
};
If there is a rescan operation running, 'flags' field is set to 1, and
'progress' field is set to aproppriate value which represents the progress
of the operation.
BTRFS_IOC_QUOTA_RESCAN - Starting a rescan operation
Start ar rescan operation to Trash all quota groups and scan the metadata
again with the current config. Before calling this ioctl,
BTRFS_IOC_QUOTA_RESCAN_STATUS sould be run to check if there is already a
rescan operation runing. After that ioctl call, the received
'struct btrfs_ioctl_quota_rescan_args' should be than passed as this ioctls
third argument.
BTRFS_IOC_QUOTA_RESCAN_WAIT - Waiting for a rescan operation to finish
Wait until a rescan operation is finished (if there is a rescan operation
running). The third ioctls argument is ignored.
Implementation notes:
Almost all of the ioctls in this patch use structure types as third arguments.
That is the reason why aproppriate thunk definitions were added in file
'syscall_types.h'.
Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200823195014.116226-8-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
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