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Message-ID: <6cc9dca0-52f6-44f8-87d4-9a937e3f83e6@redhat.com>
Date: Thu, 1 Feb 2024 08:26:02 +0800
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Subject: Re: [PATCH] fscrypt: to make sure the inode->i_blkbits is correctly
 set
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To: Eric Biggers <ebiggers@kernel.org>
Cc: linux-fscrypt@vger.kernel.org, tytso@mit.edu, jaegeuk@kernel.org,
 linux-kernel@vger.kernel.org, idryomov@gmail.com,
 ceph-devel@vger.kernel.org, jlayton@kernel.org, vshankar@redhat.com
References: <20240125044826.1294268-1-xiubli@redhat.com>
 <20240127063754.GA11935@sol.localdomain>
From: Xiubo Li <xiubli@redhat.com>
In-Reply-To: <20240127063754.GA11935@sol.localdomain>
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On 1/27/24 14:37, Eric Biggers wrote:
> On Thu, Jan 25, 2024 at 12:48:25PM +0800, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> The inode->i_blkbits should be already set before calling
>> fscrypt_get_encryption_info() and it will be used this to setup the
>> ci_data_unit_bits.
>>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>   fs/crypto/keysetup.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
>> index d71f7c799e79..909187e52bae 100644
>> --- a/fs/crypto/keysetup.c
>> +++ b/fs/crypto/keysetup.c
>> @@ -702,6 +702,9 @@ int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported)
>>   /**
>>    * fscrypt_prepare_new_inode() - prepare to create a new inode in a directory
>>    * @dir: a possibly-encrypted directory
>>    * @inode: the new inode.  ->i_mode must be set already.
>>    *         ->i_ino doesn't need to be set yet.
> Maybe just change the above to "->i_mode and ->i_blkbits", instead of adding a
> separate paragraph?

Just back from PTO.

Yeah, this sounds much better. I will fix it.

Thanks

- Xiubo


>>    * @encrypt_ret: (output) set to %true if the new inode will be encrypted
>>    *
>>    * If the directory is encrypted, set up its ->i_crypt_info in preparation for
>>    * encrypting the name of the new file.  Also, if the new inode will be
>>    * encrypted, set up its ->i_crypt_info and set *encrypt_ret=true.
>>    *
>>    * This isn't %GFP_NOFS-safe, and therefore it should be called before starting
>>    * any filesystem transaction to create the inode.  For this reason, ->i_ino
>>    * isn't required to be set yet, as the filesystem may not have set it yet.
>>    *
>>    * This doesn't persist the new inode's encryption context.  That still needs to
>>    * be done later by calling fscrypt_set_context().
>>    *
>> + * Please note that the inode->i_blkbits should be already set before calling
>> + * this and later it will be used to setup the ci_data_unit_bits.
>> + *
>>    * Return: 0 on success, -ENOKEY if the encryption key is missing, or another
>>    *	   -errno code
>>    */
>> @@ -717,6 +720,9 @@ int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode,
>>   	if (IS_ERR(policy))
>>   		return PTR_ERR(policy);
>>   
>> +	if (WARN_ON_ONCE(inode->i_blkbits == 0))
>> +		return -EINVAL;
>> +
> Thanks,
>
> - Eric
>