Re: [PATCH 1/2] staging: erofs: add requirements field in superblock
On 2019/6/11 9:43, Gao Xiang wrote:
> Hi Chao,
>
> On 2019/6/11 9:37, Chao Yu wrote:
>> On 2019/6/10 17:36, Gao Xiang wrote:
>>> There are some backward incompatible optimizations 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: # 4.19+
>>> Signed-off-by: Gao Xiang
>>> ---
>>> drivers/staging/erofs/erofs_fs.h | 11 +--
>>> drivers/staging/erofs/super.c| 8
>>> 2 files changed, 17 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/staging/erofs/erofs_fs.h
>>> b/drivers/staging/erofs/erofs_fs.h
>>> index fa52898df006..531821757845 100644
>>> --- a/drivers/staging/erofs/erofs_fs.h
>>> +++ b/drivers/staging/erofs/erofs_fs.h
>>> @@ -17,10 +17,16 @@
>>> #define EROFS_SUPER_MAGIC_V10xE0F5E1E2
>>> #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;/* extra features for the image */
>>> /* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
>>> /* 13 */__u8 reserved;
>>>
>>> @@ -34,8 +40,9 @@ 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;/* all mandatory minimum requirements */
>>>
>>> -/* 80 */__u8 reserved2[48]; /* 128 bytes */
>>> +/* 84 */__u8 reserved2[44]; /* 128 bytes */
>>
>> Xiang,
>>
>> It needs to update the comment behind reserved2, it's locating at 132 bytes.
>
> I don't get the point... the whole struct is totally 128bytes I think?
Xiang, I misunderstood meaning of comments, please ignore it, sorry. :)
Thanks,
>
>>
>>> } __packed;
>>>
>>> /*
>>> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
>>> index f580d4ef77a1..815e5825db59 100644
>>> --- a/drivers/staging/erofs/super.c
>>> +++ b/drivers/staging/erofs/super.c
>>> @@ -104,6 +104,14 @@ static int superblock_read(struct super_block *sb)
>>> goto out;
>>> }
>>>
>>> + /* check if the kernel meets all mandatory requirements */
>>> + if (le32_to_cpu(layout->requirements) & (~EROFS_ALL_REQUIREMENTS)) {
>>> + errln("too old to meet minimum requirements: %x supported: %x",
>>
>> It will be better to give a suggestion to user to upgrade kernel version to
>> match the image with new layout, otherwise it's just a little confused about
>> above printed message.
>
> OK, I will refine the printed message :)
>
> Thanks,
> Gao Xiang
>
>>
>> Thanks,
>>
>>> + le32_to_cpu(layout->requirements),
>>> + EROFS_ALL_REQUIREMENTS);
>>> + goto out;
>>> + }
>>> +
>>> sbi->blocks = le32_to_cpu(layout->blocks);
>>> sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
>>> #ifdef CONFIG_EROFS_FS_XATTR
>>>
> .
>
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Re: [PATCH 1/2] staging: erofs: add requirements field in superblock
Hi Chao,
On 2019/6/11 9:37, Chao Yu wrote:
> On 2019/6/10 17:36, Gao Xiang wrote:
>> There are some backward incompatible optimizations 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: # 4.19+
>> Signed-off-by: Gao Xiang
>> ---
>> drivers/staging/erofs/erofs_fs.h | 11 +--
>> drivers/staging/erofs/super.c| 8
>> 2 files changed, 17 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/erofs/erofs_fs.h
>> b/drivers/staging/erofs/erofs_fs.h
>> index fa52898df006..531821757845 100644
>> --- a/drivers/staging/erofs/erofs_fs.h
>> +++ b/drivers/staging/erofs/erofs_fs.h
>> @@ -17,10 +17,16 @@
>> #define EROFS_SUPER_MAGIC_V10xE0F5E1E2
>> #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;/* extra features for the image */
>> /* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
>> /* 13 */__u8 reserved;
>>
>> @@ -34,8 +40,9 @@ 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;/* all mandatory minimum requirements */
>>
>> -/* 80 */__u8 reserved2[48]; /* 128 bytes */
>> +/* 84 */__u8 reserved2[44]; /* 128 bytes */
>
> Xiang,
>
> It needs to update the comment behind reserved2, it's locating at 132 bytes.
I don't get the point... the whole struct is totally 128bytes I think?
>
>> } __packed;
>>
>> /*
>> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
>> index f580d4ef77a1..815e5825db59 100644
>> --- a/drivers/staging/erofs/super.c
>> +++ b/drivers/staging/erofs/super.c
>> @@ -104,6 +104,14 @@ static int superblock_read(struct super_block *sb)
>> goto out;
>> }
>>
>> +/* check if the kernel meets all mandatory requirements */
>> +if (le32_to_cpu(layout->requirements) & (~EROFS_ALL_REQUIREMENTS)) {
>> +errln("too old to meet minimum requirements: %x supported: %x",
>
> It will be better to give a suggestion to user to upgrade kernel version to
> match the image with new layout, otherwise it's just a little confused about
> above printed message.
OK, I will refine the printed message :)
Thanks,
Gao Xiang
>
> Thanks,
>
>> + le32_to_cpu(layout->requirements),
>> + EROFS_ALL_REQUIREMENTS);
>> +goto out;
>> +}
>> +
>> sbi->blocks = le32_to_cpu(layout->blocks);
>> sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
>> #ifdef CONFIG_EROFS_FS_XATTR
>>
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Re: [PATCH 1/2] staging: erofs: add requirements field in superblock
On 2019/6/10 17:36, Gao Xiang wrote:
> There are some backward incompatible optimizations 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: # 4.19+
> Signed-off-by: Gao Xiang
> ---
> drivers/staging/erofs/erofs_fs.h | 11 +--
> drivers/staging/erofs/super.c| 8
> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/erofs/erofs_fs.h
> b/drivers/staging/erofs/erofs_fs.h
> index fa52898df006..531821757845 100644
> --- a/drivers/staging/erofs/erofs_fs.h
> +++ b/drivers/staging/erofs/erofs_fs.h
> @@ -17,10 +17,16 @@
> #define EROFS_SUPER_MAGIC_V10xE0F5E1E2
> #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;/* extra features for the image */
> /* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
> /* 13 */__u8 reserved;
>
> @@ -34,8 +40,9 @@ 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;/* all mandatory minimum requirements */
>
> -/* 80 */__u8 reserved2[48]; /* 128 bytes */
> +/* 84 */__u8 reserved2[44]; /* 128 bytes */
Xiang,
It needs to update the comment behind reserved2, it's locating at 132 bytes.
> } __packed;
>
> /*
> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
> index f580d4ef77a1..815e5825db59 100644
> --- a/drivers/staging/erofs/super.c
> +++ b/drivers/staging/erofs/super.c
> @@ -104,6 +104,14 @@ static int superblock_read(struct super_block *sb)
> goto out;
> }
>
> + /* check if the kernel meets all mandatory requirements */
> + if (le32_to_cpu(layout->requirements) & (~EROFS_ALL_REQUIREMENTS)) {
> + errln("too old to meet minimum requirements: %x supported: %x",
It will be better to give a suggestion to user to upgrade kernel version to
match the image with new layout, otherwise it's just a little confused about
above printed message.
Thanks,
> + le32_to_cpu(layout->requirements),
> + EROFS_ALL_REQUIREMENTS);
> + goto out;
> + }
> +
> sbi->blocks = le32_to_cpu(layout->blocks);
> sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
> #ifdef CONFIG_EROFS_FS_XATTR
>
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[PATCH 1/2] staging: erofs: add requirements field in superblock
There are some backward incompatible optimizations 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: # 4.19+
Signed-off-by: Gao Xiang
---
drivers/staging/erofs/erofs_fs.h | 11 +--
drivers/staging/erofs/super.c| 8
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h
index fa52898df006..531821757845 100644
--- a/drivers/staging/erofs/erofs_fs.h
+++ b/drivers/staging/erofs/erofs_fs.h
@@ -17,10 +17,16 @@
#define EROFS_SUPER_MAGIC_V10xE0F5E1E2
#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;/* extra features for the image */
/* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
/* 13 */__u8 reserved;
@@ -34,8 +40,9 @@ 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;/* all mandatory minimum requirements */
-/* 80 */__u8 reserved2[48]; /* 128 bytes */
+/* 84 */__u8 reserved2[44]; /* 128 bytes */
} __packed;
/*
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index f580d4ef77a1..815e5825db59 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -104,6 +104,14 @@ static int superblock_read(struct super_block *sb)
goto out;
}
+ /* check if the kernel meets all mandatory requirements */
+ if (le32_to_cpu(layout->requirements) & (~EROFS_ALL_REQUIREMENTS)) {
+ errln("too old to meet minimum requirements: %x supported: %x",
+ le32_to_cpu(layout->requirements),
+ EROFS_ALL_REQUIREMENTS);
+ goto out;
+ }
+
sbi->blocks = le32_to_cpu(layout->blocks);
sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
#ifdef CONFIG_EROFS_FS_XATTR
--
2.17.1
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