@@ -47,9 +47,11 @@ struct cachefiles_volume {
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. */
};
struct cachefiles_ondemand_info {
+ struct work_struct ondemand_work;
int ondemand_id;
enum cachefiles_object_state state;
struct cachefiles_object *object;
@@ -326,6 +328,7 @@ 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);
#else
static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
char __user *_buffer, size_t buflen)
@@ -18,14 +18,10 @@ static int cachefiles_ondemand_fd_release(struct inode *inode,
info->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED;
cachefiles_ondemand_set_object_close(object);
- /*
- * Flush all pending READ requests since their completion depends on
- * anon_fd.
- */
- xas_for_each(&xas, req, ULONG_MAX) {
+ /* Only flush CACHEFILES_REQ_NEW marked req to avoid race with daemon_read */
+ xas_for_each_marked(&xas, req, ULONG_MAX, CACHEFILES_REQ_NEW) {
if (req->msg.object_id == object_id &&
- req->msg.opcode == CACHEFILES_OP_READ) {
- req->error = -EIO;
+ req->msg.opcode == CACHEFILES_OP_CLOSE) {
complete(&req->done);
xas_store(&xas, NULL);
}
@@ -179,6 +175,7 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
trace_cachefiles_ondemand_copen(req->object, id, size);
cachefiles_ondemand_set_object_open(req->object);
+ wake_up_all(&cache->daemon_pollwq);
out:
complete(&req->done);
@@ -222,7 +219,6 @@ static int cachefiles_ondemand_get_fd(struct cachefiles_req *req)
load = (void *)req->msg.data;
load->fd = fd;
- req->msg.object_id = object_id;
object->ondemand->ondemand_id = object_id;
cachefiles_get_unbind_pincount(cache);
@@ -238,6 +234,43 @@ static int cachefiles_ondemand_get_fd(struct cachefiles_req *req)
return ret;
}
+static void ondemand_object_worker(struct work_struct *work)
+{
+ struct cachefiles_ondemand_info *info =
+ container_of(work, struct cachefiles_ondemand_info, ondemand_work);
+
+ cachefiles_ondemand_init_object(info->object);
+}
+
+/*
+ * If there are any inflight or subsequent READ requests on the
+ * closed object, reopen it.
+ * Skip read requests whose related object is reopening.
+ */
+static struct cachefiles_req *cachefiles_ondemand_select_req(struct xa_state *xas,
+ unsigned long xa_max)
+{
+ struct cachefiles_req *req;
+ struct cachefiles_object *object;
+ struct cachefiles_ondemand_info *info;
+
+ xas_for_each_marked(xas, req, xa_max, CACHEFILES_REQ_NEW) {
+ if (req->msg.opcode != CACHEFILES_OP_READ)
+ return req;
+ object = req->object;
+ info = object->ondemand;
+ if (cachefiles_ondemand_object_is_close(object)) {
+ cachefiles_ondemand_set_object_reopening(object);
+ queue_work(fscache_wq, &info->ondemand_work);
+ continue;
+ }
+ if (cachefiles_ondemand_object_is_reopening(object))
+ continue;
+ return req;
+ }
+ return NULL;
+}
+
ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
char __user *_buffer, size_t buflen)
{
@@ -248,16 +281,16 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
int ret = 0;
XA_STATE(xas, &cache->reqs, cache->req_id_next);
+ xa_lock(&cache->reqs);
/*
* Cyclically search for a request that has not ever been processed,
* to prevent requests from being processed repeatedly, and make
* request distribution fair.
*/
- xa_lock(&cache->reqs);
- req = xas_find_marked(&xas, UINT_MAX, CACHEFILES_REQ_NEW);
+ req = cachefiles_ondemand_select_req(&xas, ULONG_MAX);
if (!req && cache->req_id_next > 0) {
xas_set(&xas, 0);
- req = xas_find_marked(&xas, cache->req_id_next - 1, CACHEFILES_REQ_NEW);
+ req = cachefiles_ondemand_select_req(&xas, cache->req_id_next - 1);
}
if (!req) {
xa_unlock(&cache->reqs);
@@ -277,14 +310,18 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
xa_unlock(&cache->reqs);
id = xas.xa_index;
- msg->msg_id = id;
if (msg->opcode == CACHEFILES_OP_OPEN) {
ret = cachefiles_ondemand_get_fd(req);
- if (ret)
+ if (ret) {
+ cachefiles_ondemand_set_object_close(req->object);
goto error;
+ }
}
+ msg->msg_id = id;
+ msg->object_id = req->object->ondemand->ondemand_id;
+
if (copy_to_user(_buffer, msg, n) != 0) {
ret = -EFAULT;
goto err_put_fd;
@@ -317,19 +354,23 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
void *private)
{
struct cachefiles_cache *cache = object->volume->cache;
- struct cachefiles_req *req;
+ struct cachefiles_req *req = NULL;
XA_STATE(xas, &cache->reqs, 0);
int ret;
if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags))
return 0;
- if (test_bit(CACHEFILES_DEAD, &cache->flags))
- return -EIO;
+ if (test_bit(CACHEFILES_DEAD, &cache->flags)) {
+ ret = -EIO;
+ goto out;
+ }
req = kzalloc(sizeof(*req) + data_len, GFP_KERNEL);
- if (!req)
- return -ENOMEM;
+ if (!req) {
+ ret = -ENOMEM;
+ goto out;
+ }
req->object = object;
init_completion(&req->done);
@@ -367,7 +408,7 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
/* coupled with the barrier in cachefiles_flush_reqs() */
smp_mb();
- if (opcode != CACHEFILES_OP_OPEN &&
+ if (opcode == CACHEFILES_OP_CLOSE &&
!cachefiles_ondemand_object_is_open(object)) {
WARN_ON_ONCE(object->ondemand->ondemand_id == 0);
xas_unlock(&xas);
@@ -392,7 +433,15 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
wake_up_all(&cache->daemon_pollwq);
wait_for_completion(&req->done);
ret = req->error;
+ kfree(req);
+ return ret;
out:
+ /* Reset the object to close state in error handling path.
+ * If error occurs after creating the anonymous fd,
+ * cachefiles_ondemand_fd_release() will set object to close.
+ */
+ if (opcode == CACHEFILES_OP_OPEN)
+ cachefiles_ondemand_set_object_close(object);
kfree(req);
return ret;
}
@@ -439,7 +488,6 @@ static int cachefiles_ondemand_init_close_req(struct cachefiles_req *req,
if (!cachefiles_ondemand_object_is_open(object))
return -ENOENT;
- req->msg.object_id = object->ondemand->ondemand_id;
trace_cachefiles_ondemand_close(object, &req->msg);
return 0;
}
@@ -455,16 +503,7 @@ static int cachefiles_ondemand_init_read_req(struct cachefiles_req *req,
struct cachefiles_object *object = req->object;
struct cachefiles_read *load = (void *)req->msg.data;
struct cachefiles_read_ctx *read_ctx = private;
- int object_id = object->ondemand->ondemand_id;
-
- /* Stop enqueuing requests when daemon has closed anon_fd. */
- if (!cachefiles_ondemand_object_is_open(object)) {
- WARN_ON_ONCE(object_id == 0);
- pr_info_once("READ: anonymous fd closed prematurely.\n");
- return -EIO;
- }
- req->msg.object_id = object_id;
load->off = read_ctx->off;
load->len = read_ctx->len;
trace_cachefiles_ondemand_read(object, &req->msg, load);
@@ -513,6 +552,7 @@ int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,
return -ENOMEM;
object->ondemand->object = object;
+ INIT_WORK(&object->ondemand->ondemand_work, ondemand_object_worker);
return 0;
}