diff options
| author | Gao Xiang <gaoxiang25@huawei.com> | 2019-06-13 16:35:41 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-25 11:36:01 +0800 |
| commit | 64e370233a0781aa0954ed4079e90d0bdb748b0e (patch) | |
| tree | 13b178bc4945406edaa0a27e9277860ce5f590da /drivers/staging/erofs/erofs_fs.h | |
| parent | e6803ce36d496bc8173e3a32f5d396ead5afac02 (diff) | |
staging: erofs: add requirements field in superblock
commit 5efe5137f05bbb4688890620934538c005e7d1d6 upstream.
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/erofs_fs.h')
| -rw-r--r-- | drivers/staging/erofs/erofs_fs.h | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h index 2f8e2bf70941..7677da889f12 100644 --- a/drivers/staging/erofs/erofs_fs.h +++ b/drivers/staging/erofs/erofs_fs.h @@ -17,10 +17,16 @@ #define EROFS_SUPER_MAGIC_V1 0xE0F5E1E2 #define EROFS_SUPER_OFFSET 1024 +/* + * Any bits that aren't in EROFS_ALL_REQUIREMENTS should be + * incompatible with this kernel version. + */ +#define EROFS_ALL_REQUIREMENTS 0 + struct erofs_super_block { /* 0 */__le32 magic; /* in the little endian */ /* 4 */__le32 checksum; /* crc32c(super_block) */ -/* 8 */__le32 features; +/* 8 */__le32 features; /* (aka. feature_compat) */ /* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */ /* 13 */__u8 reserved; @@ -34,9 +40,10 @@ struct erofs_super_block { /* 44 */__le32 xattr_blkaddr; /* 48 */__u8 uuid[16]; /* 128-bit uuid for volume */ /* 64 */__u8 volume_name[16]; /* volume name */ +/* 80 */__le32 requirements; /* (aka. feature_incompat) */ -/* 80 */__u8 reserved2[48]; /* 128 bytes */ -} __packed; +/* 84 */__u8 reserved2[44]; +} __packed; /* 128 bytes */ #define __EROFS_BIT(_prefix, _cur, _pre) enum { \ _prefix ## _cur ## _BIT = _prefix ## _pre ## _BIT + \ |