btrfs: retrieve more info from FS_INFO ioctl

Provide the basic information about filesystem through the ioctl:
* b-tree node size (same as leaf size)
* sector size
* expected alignment of CLONE_RANGE and EXTENT_SAME ioctl arguments

Backward compatibility: if the values are 0, kernel does not provide
this information, the applications should ignore them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
David Sterba 2014-05-07 18:17:06 +02:00 committed by Chris Mason
parent 7d824b6f9c
commit 80a773fbfc
2 changed files with 9 additions and 1 deletions

View file

@ -2574,6 +2574,10 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
}
mutex_unlock(&fs_devices->device_list_mutex);
fi_args->nodesize = root->fs_info->super_copy->nodesize;
fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
ret = -EFAULT;

View file

@ -181,7 +181,11 @@ struct btrfs_ioctl_fs_info_args {
__u64 max_id; /* out */
__u64 num_devices; /* out */
__u8 fsid[BTRFS_FSID_SIZE]; /* out */
__u64 reserved[124]; /* pad to 1k */
__u32 nodesize; /* out */
__u32 sectorsize; /* out */
__u32 clone_alignment; /* out */
__u32 reserved32;
__u64 reserved[122]; /* pad to 1k */
};
struct btrfs_ioctl_feature_flags {