cachefiles: stop sending new request when dropping object

Added CACHEFILES_ONDEMAND_OBJSTATE_DROPPING indicates that the cachefiles
object is being dropped, and is set after the close request for the dropped
object completes, and no new requests are allowed to be sent after this
state.

This prepares for the later addition of cancel_work_sync(). It prevents
leftover reopen requests from being sent, to avoid processing unnecessary
requests and to avoid cancel_work_sync() blocking by waiting for daemon to
complete the reopen requests.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240628062930.2467993-6-libaokun@huaweicloud.com
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index d33169f0018b103a7ad30ed20b258869e740e556..8ecd296cc1c40ac9998e9c617772281223677b63 100644 (file)
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -48,6 +48,7 @@ enum cachefiles_object_state {
        CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */
        CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */
        CACHEFILES_ONDEMAND_OBJSTATE_REOPENING, /* Object that was closed and is being reopened. */
+       CACHEFILES_ONDEMAND_OBJSTATE_DROPPING, /* Object is being dropped. */
 };
 
 struct cachefiles_ondemand_info {
@@ -332,6 +333,7 @@ cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
 CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);
 CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);
 CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);
+CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING);
 
 static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
 {

diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 4ba42f1fa3b4077b04735282354de250e70fe87d..73da4d4eaa9bc8abec79e9bfd8e26c67557953b3 100644 (file)
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -422,7 +422,8 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
                 */
                xas_lock(&xas);
 
-               if (test_bit(CACHEFILES_DEAD, &cache->flags)) {
+               if (test_bit(CACHEFILES_DEAD, &cache->flags) ||
+                   cachefiles_ondemand_object_is_dropping(object)) {
                        xas_unlock(&xas);
                        ret = -EIO;
                        goto out;
@@ -463,7 +464,8 @@ out:
         * If error occurs after creating the anonymous fd,
         * cachefiles_ondemand_fd_release() will set object to close.
         */
-       if (opcode == CACHEFILES_OP_OPEN)
+       if (opcode == CACHEFILES_OP_OPEN &&
+           !cachefiles_ondemand_object_is_dropping(object))
                cachefiles_ondemand_set_object_close(object);
        kfree(req);
        return ret;
@@ -562,8 +564,12 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object)
 
 void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
 {
+       if (!object->ondemand)
+               return;
+
        cachefiles_ondemand_send_req(object, CACHEFILES_OP_CLOSE, 0,
                        cachefiles_ondemand_init_close_req, NULL);
+       cachefiles_ondemand_set_object_dropping(object);
 }
 
 int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,