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| author | Gao Xiang <gaoxiang25@huawei.com> | 2019-06-13 16:35:41 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-17 22:58:58 +0200 |
| commit | 5efe5137f05bbb4688890620934538c005e7d1d6 (patch) | |
| tree | 09e24c8e400535156cca7c8e51d231befe81c633 /drivers/staging/erofs/super.c | |
| parent | f2c7c76c5d0a443053e94adb9f0918fa2fb85c3a (diff) | |
| download | linux-5efe5137f05bbb4688890620934538c005e7d1d6.tar.bz2 | |
staging: erofs: add requirements field in superblock
There are some backward incompatible features pending
for months, mainly due to on-disk format expensions.
However, we should ensure that it cannot be mounted with
old kernels. Otherwise, it will causes unexpected behaviors.
Fixes: ba2b77a82022 ("staging: erofs: add super block operations")
Cc: <stable@vger.kernel.org> # 4.19+
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/erofs/super.c')
| -rw-r--r-- | drivers/staging/erofs/super.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c index f580d4ef77a1..cadbcc11702a 100644 --- a/drivers/staging/erofs/super.c +++ b/drivers/staging/erofs/super.c @@ -71,6 +71,22 @@ static void free_inode(struct inode *inode) kmem_cache_free(erofs_inode_cachep, vi); } +static bool check_layout_compatibility(struct super_block *sb, + struct erofs_super_block *layout) +{ + const unsigned int requirements = le32_to_cpu(layout->requirements); + + EROFS_SB(sb)->requirements = requirements; + + /* check if current kernel meets all mandatory requirements */ + if (requirements & (~EROFS_ALL_REQUIREMENTS)) { + errln("unidentified requirements %x, please upgrade kernel version", + requirements & ~EROFS_ALL_REQUIREMENTS); + return false; + } + return true; +} + static int superblock_read(struct super_block *sb) { struct erofs_sb_info *sbi; @@ -104,6 +120,9 @@ static int superblock_read(struct super_block *sb) goto out; } + if (!check_layout_compatibility(sb, layout)) + goto out; + sbi->blocks = le32_to_cpu(layout->blocks); sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr); #ifdef CONFIG_EROFS_FS_XATTR |