[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 3/4] linux-user: Add support for a group of btrfs ioctls used
|
From: |
Laurent Vivier |
|
Subject: |
Re: [PATCH 3/4] linux-user: Add support for a group of btrfs ioctls used to manipulate with devices |
|
Date: |
Wed, 29 Jul 2020 18:00:28 +0200 |
|
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 |
Le 09/07/2020 à 17:52, Filip Bozuta a écrit :
> This patch implements functionality for following ioctls:
>
> BTRFS_IOC_SCAN_DEV - Scanning device for a btrfs filesystem
>
> Scan a device for a btrfs filesystem. The device that is to
> be scanned is passed in the ioctl's third argument which
> represents a pointer to a 'struct ioc_vol_args' (which was
> mentioned in a previous patch). Before calling this ioctl,
> the name field of this structure should be filled with the
> aproppriate name value which represents a path for the device.
> If the device contains a btrfs filesystem, the ioctl returns 0,
> otherwise a negative value is returned.
>
> BTRFS_IOC_ADD_DEV - Adding a device to a btrfs filesystem
>
> Add a device to a btrfs filesystem. The device that is to be
> added is passed in the ioctl's third argument which represents
> a pointer to a 'struct ioc_vol_args' (which was mentioned in
> a previous patch). Before calling this ioctl, the name field of
> this structure should be filled with the aproppriate name value
> which represents a path for the device.
>
> BTRFS_IOC_RM_DEV - Removing a device from a btrfs filesystem
>
> Remove a device from a btrfs filesystem. The device that is to be
> removed is passed in the ioctl's third argument which represents
> a pointer to a 'struct ioc_vol_args' (which was mentioned in
> a previous patch). Before calling this ioctl, the name field of
> this structure should be filled with the aproppriate name value
> which represents a path for the device.
>
> BTRFS_IOC_DEV_INFO - Getting information about a device
>
> Obtain information for device in a btrfs filesystem. The information
> is gathered in the ioctl's third argument which represents a pointer
> to a following structure type:
>
> struct btrfs_ioctl_dev_info_args {
> __u64 devid; /* in/out */
> __u8 uuid[BTRFS_UUID_SIZE]; /* in/out */
> __u64 bytes_used; /* out */
> __u64 total_bytes; /* out */
> __u64 unused[379]; /* pad to 4k */
> __u8 path[BTRFS_DEVICE_PATH_NAME_MAX]; /* out */
> };
>
> Before calling this ioctl, field "devid" should be set with the id value
> for the device for which the information is to be obtained. If this field
> is not aproppriately set, the errno ENODEV ("No such device") is returned.
>
> BTRFS_IOC_GET_DEV_STATS - Getting device statistics
>
> Obtain stats informatin for device in a btrfs filesystem. The information
> is gathered in the ioctl's third argument which represents a pointer to
> a following structure type:
>
> struct btrfs_ioctl_get_dev_stats {
> __u64 devid; /* in */
> __u64 nr_items; /* in/out */
> __u64 flags; /* in/out */
>
> /* out values: */
> __u64 values[BTRFS_DEV_STAT_VALUES_MAX];
>
> /*
> * This pads the struct to 1032 bytes. It was originally meant to pad to
> * 1024 bytes, but when adding the flags field, the padding calculation
> * was not adjusted.
> */
> __u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX];
> };
>
> Before calling this ioctl, field "devid" should be set with the id value
> for the device for which the information is to be obtained. If this field
> is not aproppriately set, the errno ENODEV ("No such device") is returned.
>
> BTRFS_IOC_FORGET_DEV - Remove unmounted devices
>
> Search and remove all stale devices (devices which are not mounted).
> The third ioctl argument is a pointer to a 'struct btrfs_ioctl_vol_args'.
> The ioctl call will release all unmounted devices which match the path
> which is specified in the "name" field of the structure. If an empty
> path ("") is specified, all unmounted devices will be released.
>
> Implementation notes:
>
> Ioctls BTRFS_IOC_DEV_INFO and BTRFS_IOC_GET_DEV_STATS use types
> 'struct btrfs_ioctl_dev_info_args' and ' struct btrfs_ioctl_get_dev_stats'
> as third argument types. That is the reason why corresponding structure
> definitions were added in file 'linux-user/syscall_types.h'.
> Since the thunk type for 'struct ioc_vol_args' was already added in a
> previous patch, the rest of the implementation was straightforward.
>
> Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
> ---
> linux-user/ioctls.h | 24 ++++++++++++++++++++++++
> linux-user/syscall_defs.h | 12 ++++++++++++
> linux-user/syscall_types.h | 16 ++++++++++++++++
> 3 files changed, 52 insertions(+)
>
> diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
> index 2422675dd0..c20bd97736 100644
> --- a/linux-user/ioctls.h
> +++ b/linux-user/ioctls.h
> @@ -178,6 +178,22 @@
> IOCTL(BTRFS_IOC_SNAP_CREATE, IOC_W,
> MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> #endif
> +#ifdef BTRFS_IOC_SCAN_DEV
> + IOCTL(BTRFS_IOC_SCAN_DEV, IOC_W,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> +#endif
> +#ifdef BTRFS_IOC_FORGET_DEV
> + IOCTL(BTRFS_IOC_FORGET_DEV, IOC_W,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> +#endif
> +#ifdef BTRFS_IOC_ADD_DEV
> + IOCTL(BTRFS_IOC_ADD_DEV, IOC_W,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> +#endif
> +#ifdef BTRFS_IOC_RM_DEV
> + IOCTL(BTRFS_IOC_RM_DEV, IOC_W,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> +#endif
> #ifdef BTRFS_IOC_SUBVOL_CREATE
> IOCTL(BTRFS_IOC_SUBVOL_CREATE, IOC_W,
> MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
> @@ -192,6 +208,14 @@
> #ifdef BTRFS_IOC_SUBVOL_SETFLAGS
> IOCTL(BTRFS_IOC_SUBVOL_SETFLAGS, IOC_W, MK_PTR(TYPE_ULONGLONG))
> #endif
> +#ifdef BTRFS_IOC_DEV_INFO
> + IOCTL(BTRFS_IOC_DEV_INFO, IOC_RW,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_dev_info_args)))
> +#endif
> +#ifdef BTRFS_IOC_GET_DEV_STATS
> + IOCTL(BTRFS_IOC_GET_DEV_STATS, IOC_RW,
> + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_get_dev_stats)))
> +#endif
> #ifdef BTRFS_IOC_GET_SUBVOL_INFO
> IOCTL(BTRFS_IOC_GET_SUBVOL_INFO, IOC_R,
> MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_get_subvol_info_args)))
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index 21d8909fd6..20c03cd145 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -970,6 +970,14 @@ struct target_rtc_pll_info {
> /* btrfs ioctls */
> #define TARGET_BTRFS_IOC_SNAP_CREATE
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> 1, struct
> btrfs_ioctl_vol_args)
> +#define TARGET_BTRFS_IOC_SCAN_DEV
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> + 4, struct
> btrfs_ioctl_vol_args)
> +#define TARGET_BTRFS_IOC_FORGET_DEV
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> + 5, struct
> btrfs_ioctl_vol_args)
> +#define TARGET_BTRFS_IOC_ADD_DEV
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> + 10, struct
> btrfs_ioctl_vol_args)
> +#define TARGET_BTRFS_IOC_RM_DEV
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> + 11, struct
> btrfs_ioctl_vol_args)
> #define TARGET_BTRFS_IOC_SUBVOL_CREATE
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> 14, struct
> btrfs_ioctl_vol_args)
> #define TARGET_BTRFS_IOC_SNAP_DESTROY
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> @@ -978,6 +986,10 @@ struct target_rtc_pll_info {
> 25, abi_ullong)
> #define TARGET_BTRFS_IOC_SUBVOL_SETFLAGS
> TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> 26, abi_ullong)
> +#define TARGET_BTRFS_IOC_DEV_INFO
> TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
> + 30, struct
> btrfs_ioctl_dev_info_args)
> +#define TARGET_BTRFS_IOC_GET_DEV_STATS
> TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
> + 52, struct
> btrfs_ioctl_get_dev_stats)
> #define TARGET_BTRFS_IOC_GET_SUBVOL_INFO
> TARGET_IOR(BTRFS_IOCTL_MAGIC, \
> 60, struct
> btrfs_ioctl_get_subvol_info_args)
>
TARGET_IOWU() and TARGET_IOWRU()
with that changed:
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Thanks,
Laurent