Commit 925bdf96 authored by Jia Zhu's avatar Jia Zhu Committed by Zizhi Wo
Browse files

cachefiles: add restore command to recover inflight ondemand read requests 

mainline inclusion
from mainline-v6.8-rc1
commit e73fa11a356ca0905c3cc648eaacc6f0f2d2c8b3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IA6I1T

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e73fa11a356ca0905c3cc648eaacc6f0f2d2c8b3



--------------------------------

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: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: default avatarJia Zhu <zhujia.zj@bytedance.com>
Signed-off-by: default avatarXin Yin <yinxin.x@bytedance.com>
Link: https://lore.kernel.org/r/20231120041422.75170-6-zhujia.zj@bytedance.com


Reviewed-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarZizhi Wo <wozizhi@huawei.com>
parent 84989f83

fs/cachefiles/daemon.c

+1 −0
Original line number Diff line number Diff line
@@ -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				}

};

fs/cachefiles/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

fs/cachefiles/ondemand.c

+23 −0
Original line number Diff line number Diff line
@@ -182,6 +182,29 @@ 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;



	/*

	 * 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;