Moving between opposite endianness will report bogus numbers in sysfs, and mount may fail as the root will not be restored correctly. If the filesystem is always used on a same endian host, this will not be a problem. Fix this by using the btrfs_set_super...() functions to set fs_info::super_copy values, and for the sysfs, use the cached fs_info::nodesize,sectorsize values.
Cc: sta...@vger.kernel.org Signed-off-by: Anand Jain <anand.j...@oracle.com> --- v2->v3: Added sysfs.c fixes. Update change log. Update $Subject. Old: [PATCH v2] btrfs: fix endianness compatibility during the SB RW v1->v2: Update change log. Update $Subject. Old: [PATCH] btrfs: use set functions to update latest refs to the SB fs/btrfs/sysfs.c | 8 +++----- fs/btrfs/transaction.c | 20 ++++++++++++-------- 2 files changed, 15 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index a8bafed931f4..d11c70bff5a9 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -423,7 +423,7 @@ static ssize_t btrfs_nodesize_show(struct kobject *kobj, { struct btrfs_fs_info *fs_info = to_fs_info(kobj); - return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); + return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->nodesize); } BTRFS_ATTR(, nodesize, btrfs_nodesize_show); @@ -433,8 +433,7 @@ static ssize_t btrfs_sectorsize_show(struct kobject *kobj, { struct btrfs_fs_info *fs_info = to_fs_info(kobj); - return snprintf(buf, PAGE_SIZE, "%u\n", - fs_info->super_copy->sectorsize); + return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->sectorsize); } BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); @@ -444,8 +443,7 @@ static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, { struct btrfs_fs_info *fs_info = to_fs_info(kobj); - return snprintf(buf, PAGE_SIZE, "%u\n", - fs_info->super_copy->sectorsize); + return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->sectorsize); } BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index f7c410f9aca2..d0fa733081ed 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1727,19 +1727,23 @@ static void update_super_roots(struct btrfs_fs_info *fs_info) super = fs_info->super_copy; + /* update latest btrfs_super_block::chunk_root refs */ root_item = &fs_info->chunk_root->root_item; - super->chunk_root = root_item->bytenr; - super->chunk_root_generation = root_item->generation; - super->chunk_root_level = root_item->level; + btrfs_set_super_chunk_root(super, root_item->bytenr); + btrfs_set_super_chunk_root_generation(super, root_item->generation); + btrfs_set_super_chunk_root_level(super, root_item->level); + /* update latest btrfs_super_block::root refs */ root_item = &fs_info->tree_root->root_item; - super->root = root_item->bytenr; - super->generation = root_item->generation; - super->root_level = root_item->level; + btrfs_set_super_root(super, root_item->bytenr); + btrfs_set_super_generation(super, root_item->generation); + btrfs_set_super_root_level(super, root_item->level); + if (btrfs_test_opt(fs_info, SPACE_CACHE)) - super->cache_generation = root_item->generation; + btrfs_set_super_cache_generation(super, root_item->generation); if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) - super->uuid_tree_generation = root_item->generation; + btrfs_set_super_uuid_tree_generation(super, + root_item->generation); } int btrfs_transaction_in_commit(struct btrfs_fs_info *info) -- 2.7.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html