Messages in this thread | | | Date | Tue, 14 Mar 2023 12:20:23 +0800 | Subject | Re: [PATCH 1/2] fscrypt: new helper function - fscrypt_prepare_atomic_open() | From | Xiubo Li <> |
| |
On 14/03/2023 10:25, Eric Biggers wrote: > On Tue, Mar 14, 2023 at 08:53:51AM +0800, Xiubo Li wrote: >> On 14/03/2023 02:09, Eric Biggers wrote: >>> On Mon, Mar 13, 2023 at 12:33:09PM +0000, Luís Henriques wrote: >>>> + * The regular open path will use fscrypt_file_open for that, but in the >>>> + * atomic open a different approach is required. >>> This should actually be fscrypt_prepare_lookup, not fscrypt_file_open, right? >>> >>>> +int fscrypt_prepare_atomic_open(struct inode *dir, struct dentry *dentry) >>>> +{ >>>> + int err; >>>> + >>>> + if (!IS_ENCRYPTED(dir)) >>>> + return 0; >>>> + >>>> + err = fscrypt_get_encryption_info(dir, true); >>>> + if (!err && !fscrypt_has_encryption_key(dir)) { >>>> + spin_lock(&dentry->d_lock); >>>> + dentry->d_flags |= DCACHE_NOKEY_NAME; >>>> + spin_unlock(&dentry->d_lock); >>>> + } >>>> + >>>> + return err; >>>> +} >>>> +EXPORT_SYMBOL_GPL(fscrypt_prepare_atomic_open); >>> [...] >>>> +static inline int fscrypt_prepare_atomic_open(struct inode *dir, >>>> + struct dentry *dentry) >>>> +{ >>>> + return -EOPNOTSUPP; >>>> +} >>> This has different behavior on unencrypted directories depending on whether >>> CONFIG_FS_ENCRYPTION is enabled or not. That's bad. >>> >>> In patch 2, the caller you are introducing has already checked IS_ENCRYPTED(). >>> >>> Also, your kerneldoc comment for fscrypt_prepare_atomic_open() says it is for >>> *encrypted* directories. >>> >>> So IMO, just remove the IS_ENCRYPTED() check from the CONFIG_FS_ENCRYPTION >>> version of fscrypt_prepare_atomic_open(). >> IMO we should keep this check in fscrypt_prepare_atomic_open() to make it >> consistent with the existing fscrypt_prepare_open(). And we can just remove >> the check from ceph instead. >> > Well, then the !CONFIG_FS_ENCRYPTION version would need to return 0 if > IS_ENCRYPTED() too.
For the !CONFIG_FS_ENCRYPTION version I think you mean:
static inline int fscrypt_prepare_atomic_open(struct inode *dir, struct dentry *dentry)
{ if (IS_ENCRYPTED(dir)) return -EOPNOTSUPP; return 0; }
> Either way would be okay, but please don't do a mix of both approaches within a > single function, as this patch currently does. > > Note that there are other fscrypt_* functions, such as fscrypt_get_symlink(), > that require an IS_ENCRYPTED() inode, so that pattern is not new.
Yeah, correct, I didn't notice that.
- Xiubo > - Eric > -- Best Regards,
Xiubo Li (李秀波)
Email: xiubli@redhat.com/xiubli@ibm.com Slack: @Xiubo Li
| |