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>
---
fs/btrfs/ioctl.c | 4 ++++
include/uapi/linux/btrfs.h | 6 +++++-
2 files changed, 9 insertions(+), 1 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2ad7de94efef..74530f226e50 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -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;
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index b4d69092fbdb..aad9391e0a6d 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -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 {
--
1.7.9
--
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