From ead1cdc1e4bb9fa4d09ca4d8af94c2687e7f5d36 Mon Sep 17 00:00:00 2001

From: Filip Bozuta <Filip.Bozuta@syrmia.com>

Date: Thu, 3 Sep 2020 01:26:56 +0200

Subject: [PATCH 4/9] linux-user: Add support for btrfs ioctls used to

 manipulate with devices

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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>

Tested-by: Daniel P. Berrangé <berrange@redhat.com>

Message-Id: <20200823195014.116226-4-Filip.Bozuta@syrmia.com>

Signed-off-by: Laurent Vivier <laurent@vivier.eu>

---

 linux-user/ioctls.h        | 24 ++++++++++++++++++++++++

 linux-user/syscall_defs.h  |  6 ++++++

 linux-user/syscall_types.h | 24 +++++++++++++++++++++++-

 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h

index f33a99f8b6..55a6cbeca5 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 a945e12547..4c7bfa0391 100644

--- a/linux-user/syscall_defs.h

+++ b/linux-user/syscall_defs.h

@@ -969,12 +969,18 @@ struct target_rtc_pll_info {

 /* btrfs ioctls */

 #define TARGET_BTRFS_IOC_SNAP_CREATE            TARGET_IOWU(BTRFS_IOCTL_MAGIC, 1)

+#define TARGET_BTRFS_IOC_SCAN_DEV               TARGET_IOWU(BTRFS_IOCTL_MAGIC, 4)

+#define TARGET_BTRFS_IOC_FORGET_DEV             TARGET_IOWU(BTRFS_IOCTL_MAGIC, 5)

+#define TARGET_BTRFS_IOC_ADD_DEV                TARGET_IOWU(BTRFS_IOCTL_MAGIC, 10)

+#define TARGET_BTRFS_IOC_RM_DEV                 TARGET_IOWU(BTRFS_IOCTL_MAGIC, 11)

 #define TARGET_BTRFS_IOC_SUBVOL_CREATE          TARGET_IOWU(BTRFS_IOCTL_MAGIC, 14)

 #define TARGET_BTRFS_IOC_SNAP_DESTROY           TARGET_IOWU(BTRFS_IOCTL_MAGIC, 15)

 #define TARGET_BTRFS_IOC_SUBVOL_GETFLAGS        TARGET_IOR(BTRFS_IOCTL_MAGIC, 25,\

                                                            abi_ullong)

 #define TARGET_BTRFS_IOC_SUBVOL_SETFLAGS        TARGET_IOW(BTRFS_IOCTL_MAGIC, 26,\

                                                            abi_ullong)

+#define TARGET_BTRFS_IOC_DEV_INFO               TARGET_IOWRU(BTRFS_IOCTL_MAGIC, 30)

+#define TARGET_BTRFS_IOC_GET_DEV_STATS          TARGET_IOWRU(BTRFS_IOCTL_MAGIC, 52)

 #define TARGET_BTRFS_IOC_GET_SUBVOL_INFO        TARGET_IORU(BTRFS_IOCTL_MAGIC, 60)

 /* usb ioctls */

diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h

index 038cd7869b..ea6898979b 100644

--- a/linux-user/syscall_types.h

+++ b/linux-user/syscall_types.h

@@ -355,7 +355,9 @@ STRUCT(blkpg_partition,

        MK_ARRAY(TYPE_CHAR, BLKPG_VOLNAMELTH)) /* volname */

 #if defined(BTRFS_IOC_SUBVOL_CREATE) || defined(BTRFS_IOC_SNAP_CREATE) || \

-    defined(BTRFS_IOC_SNAP_DESTROY)

+    defined(BTRFS_IOC_SNAP_DESTROY)  || defined(BTRFS_IOC_SCAN_DEV)  || \

+    defined(BTRFS_IOC_FORGET_DEV)    || defined(BTRFS_IOC_ADD_DEV) || \

+    defined(BTRFS_IOC_RM_DEV)        || defined(BTRFS_IOC_DEV_INFO)

 STRUCT(btrfs_ioctl_vol_args,

        TYPE_LONGLONG, /* fd */

        MK_ARRAY(TYPE_CHAR, BTRFS_PATH_NAME_MAX + 1)) /* name */

@@ -387,6 +389,26 @@ STRUCT(btrfs_ioctl_get_subvol_info_args,

        MK_ARRAY(TYPE_ULONGLONG, 8)) /* reserved */

 #endif

+#ifdef BTRFS_IOC_DEV_INFO

+STRUCT(btrfs_ioctl_dev_info_args,

+       TYPE_ULONGLONG, /* devid */

+       MK_ARRAY(TYPE_CHAR, BTRFS_UUID_SIZE), /* uuid */

+       TYPE_ULONGLONG, /* bytes_used */

+       TYPE_ULONGLONG, /* total_bytes */

+       MK_ARRAY(TYPE_ULONGLONG, 379), /* unused */

+       MK_ARRAY(TYPE_CHAR, BTRFS_DEVICE_PATH_NAME_MAX)) /* path */

+#endif

+

+#ifdef BTRFS_IOC_GET_DEV_STATS

+STRUCT(btrfs_ioctl_get_dev_stats,

+       TYPE_ULONGLONG, /* devid */

+       TYPE_ULONGLONG, /* nr_items */

+       TYPE_ULONGLONG, /* flags */

+       MK_ARRAY(TYPE_ULONGLONG, BTRFS_DEV_STAT_VALUES_MAX), /* values */

+       MK_ARRAY(TYPE_ULONGLONG,

+                128 - 2 - BTRFS_DEV_STAT_VALUES_MAX)) /* unused */

+#endif

+

 STRUCT(rtc_time,

        TYPE_INT, /* tm_sec */

        TYPE_INT, /* tm_min */

-- 

2.26.2