[PATCH 4/4] linux-user: Add support for btrfs ioctls used to scrub a filesystem

[Filip Bozuta <Filip.Bozuta@syrmia.com>]

This patch implements functionality for following ioctls:

BTRFS_IOC_SCRUB - Starting a btrfs filesystem scrub

    Start a btrfs filesystem scrub. The third ioctls argument
    is a pointer to a following type:

    struct btrfs_ioctl_scrub_args {
	__u64 devid;				/* in */
	__u64 start;				/* in */
	__u64 end;				/* in */
	__u64 flags;				/* in */
	struct btrfs_scrub_progress progress;	/* out */
	/* pad to 1k */
	__u64 unused[(1024-32-sizeof(struct btrfs_scrub_progress))/8];
    };

    Before calling this ioctl, field 'devid' should be filled
    with value that represents the device id of the btrfs filesystem
    for which the scrub is to be started.

BTRFS_IOC_SCRUB_CANCEL - Canceling scrub of a btrfs filesystem

    Cancel a btrfs filesystem scrub if it is running. The third
    ioctls argument is ignored.

BTRFS_IOC_SCRUB_PROGRESS - Getting status of a running scrub

    Read the status of a running btrfs filesystem scrub. The third
    ioctls argument is a pointer to the above mentioned
    'struct btrfs_ioctl_scrub_args'. Similarly as with 'BTRFS_IOC_SCRUB',
    the 'devid' field should be filled with value that represents the
    id of the btrfs device for which the scrub has started. The status
    of a running scrub is returned in the field 'progress' which is
    of type 'struct btrfs_scrub_progress' and its definition can be
    found at:
    https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/btrfs.h#L150

Implementation nots:

    Ioctls in this patch use type 'struct btrfs_ioctl_scrub_args' as their
    third argument. That is the reason why an aproppriate thunk type
    definition is added in file 'syscall_types.h'.
---
 linux-user/ioctls.h        | 11 +++++++++++
 linux-user/syscall_defs.h  |  6 ++++++
 linux-user/syscall_types.h | 26 ++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
index 8665f504bf..bf80615438 100644
--- a/linux-user/ioctls.h
+++ b/linux-user/ioctls.h
@@ -215,6 +215,17 @@
 #ifdef BTRFS_IOC_SUBVOL_SETFLAGS
      IOCTL(BTRFS_IOC_SUBVOL_SETFLAGS, IOC_W, MK_PTR(TYPE_ULONGLONG))
 #endif
+#ifdef BTRFS_IOC_SCRUB
+     IOCTL(BTRFS_IOC_SCRUB, IOC_RW,
+           MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_scrub_args)))
+#endif
+#ifdef BTRFS_IOC_SCRUB_CANCEL
+     IOCTL(BTRFS_IOC_SCRUB_CANCEL, 0, TYPE_NULL)
+#endif
+#ifdef BTRFS_IOC_SCRUB_PROGRESS
+     IOCTL(BTRFS_IOC_SCRUB_PROGRESS, IOC_RW,
+           MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_scrub_args)))
+#endif
 #ifdef BTRFS_IOC_DEV_INFO
      IOCTL(BTRFS_IOC_DEV_INFO, IOC_RW,
            MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_dev_info_args)))
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 3f771ae5d1..589ec3e9b0 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -990,6 +990,12 @@ 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_SCRUB                  TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
+                                             27, struct btrfs_ioctl_scrub_args)
+#define TARGET_BTRFS_IOC_SCRUB_CANCEL           TARGET_IO(BTRFS_IOCTL_MAGIC,  \
+                                                          28)
+#define TARGET_BTRFS_IOC_SCRUB_PROGRESS         TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
+                                             29, struct btrfs_ioctl_scrub_args)
 #define TARGET_BTRFS_IOC_DEV_INFO               TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
                                           30, struct btrfs_ioctl_dev_info_args)
 #define TARGET_BTRFS_IOC_INO_PATHS              TARGET_IOWR(BTRFS_IOCTL_MAGIC,\
diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h
index b4f462b5c6..345193270c 100644
--- a/linux-user/syscall_types.h
+++ b/linux-user/syscall_types.h
@@ -373,6 +373,32 @@ STRUCT(btrfs_ioctl_ino_lookup_user_args,
        MK_ARRAY(TYPE_CHAR, BTRFS_VOL_NAME_MAX + 1), /* name */
        MK_ARRAY(TYPE_CHAR, BTRFS_INO_LOOKUP_USER_PATH_MAX)) /* path */
 
+STRUCT(btrfs_scrub_progress,
+       TYPE_ULONGLONG, /* data_extents_scrubbed */
+       TYPE_ULONGLONG, /* tree_extents_scrubbed */
+       TYPE_ULONGLONG, /* data_bytes_scrubbed */
+       TYPE_ULONGLONG, /* tree_bytes_scrubbed */
+       TYPE_ULONGLONG, /* read_errors */
+       TYPE_ULONGLONG, /* csum_errors */
+       TYPE_ULONGLONG, /* verify_errors */
+       TYPE_ULONGLONG, /* no_csum */
+       TYPE_ULONGLONG, /* csum_discards */
+       TYPE_ULONGLONG, /* super_errors */
+       TYPE_ULONGLONG, /* malloc_errors */
+       TYPE_ULONGLONG, /* uncorrectable_errors */
+       TYPE_ULONGLONG, /* corrected_er */
+       TYPE_ULONGLONG, /* last_physical */
+       TYPE_ULONGLONG) /* unverified_errors */
+
+STRUCT(btrfs_ioctl_scrub_args,
+  TYPE_ULONGLONG, /* devid */
+  TYPE_ULONGLONG, /* start */
+  TYPE_ULONGLONG, /* end */
+  TYPE_ULONGLONG, /* flags */
+  MK_STRUCT(STRUCT_btrfs_scrub_progress), /* progress */
+  MK_ARRAY(TYPE_ULONGLONG,
+           (1024 - 32 - sizeof(struct btrfs_scrub_progress)) / 8)) /* unused */
+
 STRUCT(btrfs_ioctl_dev_info_args,
        TYPE_ULONGLONG, /* devid */
        MK_ARRAY(TYPE_CHAR, BTRFS_UUID_SIZE), /* uuid */
-- 
2.25.1