Re: [PATCH v6 12/22] erofs: add cookie context helper functions

JeffleXu
2022-03-28T03:11:56Z

On 3/25/22 9:41 PM, Gao Xiang wrote:
> Hi Jeffle,
>
> On Fri, Mar 25, 2022 at 08:22:13PM +0800, Jeffle Xu wrote:
>> Introduce "struct erofs_fscache" for managing cookie for backinig file,
>> and helper functions for initializing and cleaning up this context
>> structure.
>>
>> Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
>> ---
>> fs/erofs/fscache.c | 61 +++++++++++++++++++++++++++++++++++++++++++++
>> fs/erofs/internal.h | 14 +++++++++++
>> 2 files changed, 75 insertions(+)
>>
>> diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
>> index 08cf570a0810..73235fd43bf6 100644
>> --- a/fs/erofs/fscache.c
>> +++ b/fs/erofs/fscache.c
>> @@ -7,6 +7,67 @@
>>
>> static struct fscache_volume *volume;
>>
>> +static int erofs_fscache_init_cookie(struct erofs_fscache *ctx, char *path)
>> +{
>> + struct fscache_cookie *cookie;
>> +
>> + cookie = fscache_acquire_cookie(volume, FSCACHE_ADV_WANT_CACHE_SIZE,
>> + path, strlen(path),
>> + NULL, 0, 0);
>
> It'd be better to rearrange in one line?

Sure.

>
> path, strlen(path), NULL, 0, 0);
>
>> + if (!cookie)
>> + return -EINVAL;
>> +
>> + fscache_use_cookie(cookie, false);
>> + ctx->cookie = cookie;
>> + return 0;
>> +}
>> +
>> +static inline void erofs_fscache_cleanup_cookie(struct erofs_fscache *ctx)
>> +{
>> + struct fscache_cookie *cookie = ctx->cookie;
>> +
>> + fscache_unuse_cookie(cookie, NULL, NULL);
>> + fscache_relinquish_cookie(cookie, false);
>> + ctx->cookie = NULL;
>> +}
>> +
>> +/*
>> + * erofs_fscache_get - create an fscache context for blob file
>> + * @sb: superblock
>> + * @path: name of blob file
>> + *
>> + * Return: fscache context on success, ERR_PTR() on failure.
>> + */
>> +struct erofs_fscache *erofs_fscache_get(struct super_block *sb, char *path)
>
> erofs_fscache_register?

OK.

>
>> +{
>> + struct erofs_fscache *ctx;
>> + int ret;
>> +
>> + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
>> + if (!ctx)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + ret = erofs_fscache_init_cookie(ctx, path);
>
> Can we fold it here? No need to introduce such simple wrapper..
>
>> + if (ret) {
>> + erofs_err(sb, "failed to init cookie");
>
> It would be better to print the path?

OK.

>
>> + goto err;
>
> kfree(ctx);
> return ERR_PTR(ret);
>
> At least for now.

Yeah, it's better.

>
>> + }
>> +
>> + return ctx;
>> +err:
>> + kfree(ctx);
>> + return ERR_PTR(ret);
>> +}
>> +
>> +void erofs_fscache_put(struct erofs_fscache *ctx)
>
> erofs_fscache_unregister?

OK.

>
>> +{
>> + if (!ctx)
>> + return;
>> +
>> + erofs_fscache_cleanup_cookie(ctx);
>
> Fold it too, since such helper doesn't simplify code a lot but need
> to take one more time to redirect..

OK.

--
Thanks,
Jeffle