On 8/18/22 9:52 PM, Jia Zhu wrote:
> Previously, in ondemand read scenario, if the anonymous fd was closed by
> user daemon, inflight and subsequent read requests would return EIO.
> As long as the device connection is not released, user daemon can hold
> and restore inflight requests by setting the request flag to
> CACHEFILES_REQ_NEW.
>
> Suggested-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
> Signed-off-by: Xin Yin <yinxin.x@xxxxxxxxxxxxx>
> ---
> fs/cachefiles/daemon.c | 1 +
> fs/cachefiles/internal.h | 3 +++
> fs/cachefiles/ondemand.c | 23 +++++++++++++++++++++++
> 3 files changed, 27 insertions(+)
>
> diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
> index c74bd1f4ecf5..014369266cb2 100644
> --- a/fs/cachefiles/daemon.c
> +++ b/fs/cachefiles/daemon.c
> @@ -77,6 +77,7 @@ static const struct cachefiles_daemon_cmd cachefiles_daemon_cmds[] = {
> { "tag", cachefiles_daemon_tag },
> #ifdef CONFIG_CACHEFILES_ONDEMAND
> { "copen", cachefiles_ondemand_copen },
> + { "restore", cachefiles_ondemand_restore },
> #endif
> { "", NULL }
> };
> diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
> index b4af67f1cbd6..d504c61a5f03 100644
> --- a/fs/cachefiles/internal.h
> +++ b/fs/cachefiles/internal.h
> @@ -303,6 +303,9 @@ extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
> extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
> char *args);
>
> +extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache,
> + char *args);
> +
> extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);
> extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);
>
> diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
> index 79ffb19380cd..5b1c447da976 100644
> --- a/fs/cachefiles/ondemand.c
> +++ b/fs/cachefiles/ondemand.c
> @@ -178,6 +178,29 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
> return ret;
> }
>
> +int cachefiles_ondemand_restore(struct cachefiles_cache *cache, char *args)
> +{
> + struct cachefiles_req *req;
> +
> + XA_STATE(xas, &cache->reqs, 0);
> +
> + if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags))
> + return -EOPNOTSUPP;
> +
> + /*
> + * Search the requests which being processed before
> + * the user daemon crashed.
> + * Set the CACHEFILES_REQ_NEW flag and user daemon will reprocess it.
> + */
The comment can be improved as:
Reset the requests to CACHEFILES_REQ_NEW state, so that the
requests have been processed halfway before the crash of the
user daemon could be reprocessed after the recovery.
> + xas_lock(&xas);
> + xas_for_each(&xas, req, ULONG_MAX)
> + xas_set_mark(&xas, CACHEFILES_REQ_NEW);
> + xas_unlock(&xas);
> +
> + wake_up_all(&cache->daemon_pollwq);
> + return 0;
> +}
> +
> static int cachefiles_ondemand_get_fd(struct cachefiles_req *req)
> {
> struct cachefiles_object *object;
--
Thanks,
Jingbo
