Commit fca432e7 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: sysfs: fix direct super block member reads 



The following sysfs entries are reading super block member directly,
which can have a different endian and cause wrong values:

- sys/fs/btrfs/<uuid>/nodesize
- sys/fs/btrfs/<uuid>/sectorsize
- sys/fs/btrfs/<uuid>/clone_alignment

Thankfully those values (nodesize and sectorsize) are always aligned
inside the btrfs_super_block, so it won't trigger unaligned read errors,
just endian problems.

Fix them by using the native cached members instead.

Fixes: df93589a ("btrfs: export more from FS_INFO to sysfs")
CC: stable@vger.kernel.org
Reviewed-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f2363e6f

fs/btrfs/sysfs.c

+3 −3
Original line number Diff line number Diff line
@@ -1118,7 +1118,7 @@ static ssize_t btrfs_nodesize_show(struct kobject *kobj, 
{

	struct btrfs_fs_info *fs_info = to_fs_info(kobj);



	return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);

	return sysfs_emit(buf, "%u\n", fs_info->nodesize);

}



BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
@@ -1128,7 +1128,7 @@ static ssize_t btrfs_sectorsize_show(struct kobject *kobj, 
{

	struct btrfs_fs_info *fs_info = to_fs_info(kobj);



	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);

	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);

}



BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
@@ -1180,7 +1180,7 @@ static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, 
{

	struct btrfs_fs_info *fs_info = to_fs_info(kobj);



	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);

	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);

}



BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);