From 49b422a8c5d640b37cfb121e6676b8cdffb763c9 Mon Sep 17 00:00:00 2001 From: Filip Bozuta Date: Sun, 23 Aug 2020 21:50:10 +0200 Subject: [PATCH] linux-user: Add support for btrfs ioctls used to get/set features MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch implements functionality for following ioctls: BTRFS_IOC_GET_FEATURES - Getting feature flags Read feature flags for a btrfs filesystem. The feature flags are returned inside the ioctl's third argument which represents a pointer to a following structure type: struct btrfs_ioctl_feature_flags { __u64 compat_flags; __u64 compat_ro_flags; __u64 incompat_flags; }; All of the structure field represent bit masks that can be composed of values which can be found on: https://elixir.bootlin.com/linux/latest/source/fs/btrfs/ctree.h#L282 BTRFS_IOC_SET_FEATURES - Setting feature flags Set and clear feature flags for a btrfs filesystem. The feature flags are set using the ioctl's third argument which represents a 'struct btrfs_ioctl_feature_flags[2]' array. The first element of the array represent flags which are to be cleared and the second element of the array represent flags which are to be set. The second element has the priority over the first, which means that if there are matching flags in the elements, they will be set in the filesystem. If the flag values in the third argument aren't correctly set to be composed of the available predefined flag values, errno ENOPERM ("Operation not permitted") is returned. BTRFS_IOC_GET_SUPPORTED_FEATURES - Getting supported feature flags Read supported feature flags for a btrfs filesystem. The supported feature flags are read using the ioctl's third argument which represents a 'struct btrfs_ioctl_feature_flags[3]' array. The first element of this array represents all of the supported flags in the btrfs filesystem. The second element represents flags that can be safely set and third element represent flags that can be safely clearead. Implementation notes: All of the implemented ioctls use 'struct btrfs_ioctl_feature_flags' as third argument. That is the reason why a corresponding defintion was added in file 'linux-user/syscall_types.h'. Signed-off-by: Filip Bozuta Tested-by: Daniel P. Berrangé Message-Id: <20200823195014.116226-5-Filip.Bozuta@syrmia.com> Signed-off-by: Laurent Vivier --- linux-user/ioctls.h | 12 ++++++++++++ linux-user/syscall_defs.h | 3 +++ linux-user/syscall_types.h | 5 +++++ 3 files changed, 20 insertions(+) diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h index 74d73994f6..11d7361848 100644 --- a/linux-user/ioctls.h +++ b/linux-user/ioctls.h @@ -216,6 +216,18 @@ IOCTL(BTRFS_IOC_GET_DEV_STATS, IOC_RW, MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_get_dev_stats))) #endif +#ifdef BTRFS_IOC_GET_FEATURES + IOCTL(BTRFS_IOC_GET_FEATURES, IOC_R, + MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_feature_flags))) +#endif +#ifdef BTRFS_IOC_SET_FEATURES + IOCTL(BTRFS_IOC_SET_FEATURES, IOC_W, + MK_PTR(MK_ARRAY(MK_STRUCT(STRUCT_btrfs_ioctl_feature_flags), 2))) +#endif +#ifdef BTRFS_IOC_GET_SUPPORTED_FEATURES + IOCTL(BTRFS_IOC_GET_SUPPORTED_FEATURES, IOC_R, + MK_PTR(MK_ARRAY(MK_STRUCT(STRUCT_btrfs_ioctl_feature_flags), 3))) +#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 d11279b78b..f701389797 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -1019,6 +1019,9 @@ struct target_rtc_pll_info { 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_FEATURES TARGET_IORU(BTRFS_IOCTL_MAGIC, 57) +#define TARGET_BTRFS_IOC_SET_FEATURES TARGET_IOWU(BTRFS_IOCTL_MAGIC, 57) +#define TARGET_BTRFS_IOC_GET_SUPPORTED_FEATURES TARGET_IORU(BTRFS_IOCTL_MAGIC, 57) #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 7e52b7aec5..eba0c43d44 100644 --- a/linux-user/syscall_types.h +++ b/linux-user/syscall_types.h @@ -413,6 +413,11 @@ STRUCT(btrfs_ioctl_get_dev_stats, 128 - 2 - BTRFS_DEV_STAT_VALUES_MAX)) /* unused */ #endif +STRUCT(btrfs_ioctl_feature_flags, + TYPE_ULONGLONG, /* compat_flags */ + TYPE_ULONGLONG, /* compat_ro_flags */ + TYPE_ULONGLONG) /* incompat_flags */ + STRUCT(rtc_time, TYPE_INT, /* tm_sec */ TYPE_INT, /* tm_min */