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

From: Ben Hutchings
Date: Thu Dec 28 2017 - 13:01:37 EST


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;