Xiubo Li <xiubli@xxxxxxxxxx> writes: > 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. OK, thank you both for the feedback. I'll send out v2 in a few hours. But my preference will be to drop the IS_ENCRYPTED() from fscrypt_prepare_atomic_open(). The reason is that we still need to keep it in the caller function anyway, because we need to set the MDS flags accordingly (see patch 2): if (IS_ENCRYPTED(dir)) { set_bit(CEPH_MDS_R_FSCRYPT_FILE, &req->r_req_flags); err = fscrypt_prepare_atomic_open(dir, dentry); if (err) goto out_req; } Cheers, -- Luís
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