[PATCH 3.16 056/204] Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFO

[Ben Hutchings]

3.16.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Omar Sandoval <osandov@xxxxxx>

commit bea7eafdbda3ba1d4b2ccb9cca829eefb7989bb9 upstream.

fs_info->super_copy->{node,sector}size are little-endian, but the ioctl
should return the values in native endianness. Use the cached values in
btrfs_fs_info instead. Found with sparse.

Fixes: 80a773fbfc2d ("btrfs: retrieve more info from FS_INFO ioctl")
Signed-off-by: Omar Sandoval <osandov@xxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[bwh: Backported to 3.16: native nodesize and sectorsize are members of
 struct btrfs_root, not struct btrfs_fs_info]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/btrfs/ioctl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2745,9 +2745,9 @@ static long btrfs_ioctl_fs_info(struct b
 	}
 	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;
+	fi_args->nodesize = root->nodesize;
+	fi_args->sectorsize = root->sectorsize;
+	fi_args->clone_alignment = root->sectorsize;
 
 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
 		ret = -EFAULT;