static kmem_cache_t *fuse_req_cachep;
-static inline struct fuse_conn *fuse_get_conn(struct file *file)
+static struct fuse_conn *fuse_get_conn(struct file *file)
{
struct fuse_conn *fc;
spin_lock(&fuse_lock);
fc = file->private_data;
- if (fc && !fc->mounted)
+ if (fc && !fc->connected)
fc = NULL;
spin_unlock(&fuse_lock);
return fc;
}
-static inline void fuse_request_init(struct fuse_req *req)
+static void fuse_request_init(struct fuse_req *req)
{
memset(req, 0, sizeof(*req));
INIT_LIST_HEAD(&req->list);
kmem_cache_free(fuse_req_cachep, req);
}
-static inline void block_sigs(sigset_t *oldset)
+static void block_sigs(sigset_t *oldset)
{
sigset_t mask;
sigprocmask(SIG_BLOCK, &mask, oldset);
}
-static inline void restore_sigs(sigset_t *oldset)
+static void restore_sigs(sigset_t *oldset)
{
sigprocmask(SIG_SETMASK, oldset, NULL);
}
+/*
+ * Reset request, so that it can be reused
+ *
+ * The caller must be _very_ careful to make sure, that it is holding
+ * the only reference to req
+ */
void fuse_reset_request(struct fuse_req *req)
{
int preallocated = req->preallocated;
int intr;
sigset_t oldset;
+ atomic_inc(&fc->num_waiting);
block_sigs(&oldset);
intr = down_interruptible(&fc->outstanding_sem);
restore_sigs(&oldset);
- return intr ? NULL : do_get_request(fc);
+ if (intr) {
+ atomic_dec(&fc->num_waiting);
+ return NULL;
+ }
+ return do_get_request(fc);
}
+/* Must be called with fuse_lock held */
static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
{
- spin_lock(&fuse_lock);
- if (req->preallocated)
+ if (req->preallocated) {
+ atomic_dec(&fc->num_waiting);
list_add(&req->list, &fc->unused_list);
- else
+ } else
fuse_request_free(req);
/* If we are in debt decrease that first */
fc->outstanding_debt--;
else
up(&fc->outstanding_sem);
- spin_unlock(&fuse_lock);
}
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
+{
+ if (atomic_dec_and_test(&req->count)) {
+ spin_lock(&fuse_lock);
+ fuse_putback_request(fc, req);
+ spin_unlock(&fuse_lock);
+ }
+}
+
+static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req)
{
if (atomic_dec_and_test(&req->count))
fuse_putback_request(fc, req);
spin_unlock(&fuse_lock);
}
-static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
-{
- int i;
- struct fuse_init_out *arg = &req->misc.init_out;
-
- if (arg->major != FUSE_KERNEL_VERSION)
- fc->conn_error = 1;
- else {
- fc->minor = arg->minor;
- fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
- }
-
- /* After INIT reply is received other requests can go
- out. So do (FUSE_MAX_OUTSTANDING - 1) number of
- up()s on outstanding_sem. The last up() is done in
- fuse_putback_request() */
- for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
- up(&fc->outstanding_sem);
-}
-
/*
* This function is called when a request is finished. Either a reply
* has arrived or it was interrupted (and not yet sent) or some error
- * occurred during communication with userspace, or the device file was
- * closed. It decreases the reference count for the request. In case
- * of a background request the reference to the stored objects are
- * released. The requester thread is woken up (if still waiting), and
- * finally the request is either freed or put on the unused_list
+ * occurred during communication with userspace, or the device file
+ * was closed. In case of a background request the reference to the
+ * stored objects are released. The requester thread is woken up (if
+ * still waiting), the 'end' callback is called if given, else the
+ * reference to the request is released
+ *
+ * Releasing extra reference for foreground requests must be done
+ * within the same locked region as setting state to finished. This
+ * is because fuse_reset_request() may be called after request is
+ * finished and it must be the sole possessor. If request is
+ * interrupted and put in the background, it will return with an error
+ * and hence never be reset and reused.
*
* Called with fuse_lock, unlocks it
*/
static void request_end(struct fuse_conn *fc, struct fuse_req *req)
{
- int putback;
- req->finished = 1;
- putback = atomic_dec_and_test(&req->count);
- spin_unlock(&fuse_lock);
- if (req->background) {
+ list_del(&req->list);
+ req->state = FUSE_REQ_FINISHED;
+ if (!req->background) {
+ wake_up(&req->waitq);
+ fuse_put_request_locked(fc, req);
+ spin_unlock(&fuse_lock);
+ } else {
+ void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
+ req->end = NULL;
+ spin_unlock(&fuse_lock);
down_read(&fc->sbput_sem);
if (fc->mounted)
fuse_release_background(req);
up_read(&fc->sbput_sem);
+ if (end)
+ end(fc, req);
+ else
+ fuse_put_request(fc, req);
}
- wake_up(&req->waitq);
- if (req->in.h.opcode == FUSE_INIT)
- process_init_reply(fc, req);
- else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {
- /* Special case for failed iget in CREATE */
- u64 nodeid = req->in.h.nodeid;
- __fuse_get_request(req);
- fuse_reset_request(req);
- fuse_send_forget(fc, req, nodeid, 1);
- putback = 0;
- }
- if (putback)
- fuse_putback_request(fc, req);
}
/*
spin_unlock(&fuse_lock);
block_sigs(&oldset);
- wait_event_interruptible(req->waitq, req->finished);
+ wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
restore_sigs(&oldset);
spin_lock(&fuse_lock);
- if (req->finished)
+ if (req->state == FUSE_REQ_FINISHED && !req->interrupted)
return;
- req->out.h.error = -EINTR;
- req->interrupted = 1;
+ if (!req->interrupted) {
+ req->out.h.error = -EINTR;
+ req->interrupted = 1;
+ }
if (req->locked) {
/* This is uninterruptible sleep, because data is
being copied to/from the buffers of req. During
wait_event(req->waitq, !req->locked);
spin_lock(&fuse_lock);
}
- if (!req->sent && !list_empty(&req->list)) {
+ if (req->state == FUSE_REQ_PENDING) {
list_del(&req->list);
__fuse_put_request(req);
- } else if (!req->finished && req->sent)
+ } else if (req->state == FUSE_REQ_SENT)
background_request(fc, req);
}
fc->outstanding_debt++;
}
list_add_tail(&req->list, &fc->pending);
+ req->state = FUSE_REQ_PENDING;
wake_up(&fc->waitq);
}
request_send_nowait(fc, req);
}
-void fuse_send_init(struct fuse_conn *fc)
-{
- /* This is called from fuse_read_super() so there's guaranteed
- to be a request available */
- struct fuse_req *req = do_get_request(fc);
- struct fuse_init_in *arg = &req->misc.init_in;
- arg->major = FUSE_KERNEL_VERSION;
- arg->minor = FUSE_KERNEL_MINOR_VERSION;
- req->in.h.opcode = FUSE_INIT;
- req->in.numargs = 1;
- req->in.args[0].size = sizeof(*arg);
- req->in.args[0].value = arg;
- req->out.numargs = 1;
- /* Variable length arguement used for backward compatibility
- with interface version < 7.5. Rest of init_out is zeroed
- by do_get_request(), so a short reply is not a problem */
- req->out.argvar = 1;
- req->out.args[0].size = sizeof(struct fuse_init_out);
- req->out.args[0].value = &req->misc.init_out;
- request_send_background(fc, req);
-}
-
/*
* Lock the request. Up to the next unlock_request() there mustn't be
* anything that could cause a page-fault. If the request was already
* interrupted bail out.
*/
-static inline int lock_request(struct fuse_req *req)
+static int lock_request(struct fuse_req *req)
{
int err = 0;
if (req) {
* requester thread is currently waiting for it to be unlocked, so
* wake it up.
*/
-static inline void unlock_request(struct fuse_req *req)
+static void unlock_request(struct fuse_req *req)
{
if (req) {
spin_lock(&fuse_lock);
}
/* Unmap and put previous page of userspace buffer */
-static inline void fuse_copy_finish(struct fuse_copy_state *cs)
+static void fuse_copy_finish(struct fuse_copy_state *cs)
{
if (cs->mapaddr) {
kunmap_atomic(cs->mapaddr, KM_USER0);
}
/* Do as much copy to/from userspace buffer as we can */
-static inline int fuse_copy_do(struct fuse_copy_state *cs, void **val,
- unsigned *size)
+static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
{
unsigned ncpy = min(*size, cs->len);
if (val) {
* Copy a page in the request to/from the userspace buffer. Must be
* done atomically
*/
-static inline int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
- unsigned offset, unsigned count, int zeroing)
+static int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
+ unsigned offset, unsigned count, int zeroing)
{
if (page && zeroing && count < PAGE_SIZE) {
void *mapaddr = kmap_atomic(page, KM_USER1);
DECLARE_WAITQUEUE(wait, current);
add_wait_queue_exclusive(&fc->waitq, &wait);
- while (fc->mounted && list_empty(&fc->pending)) {
+ while (fc->connected && list_empty(&fc->pending)) {
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current))
break;
goto err_unlock;
request_wait(fc);
err = -ENODEV;
- if (!fc->mounted)
+ if (!fc->connected)
goto err_unlock;
err = -ERESTARTSYS;
if (list_empty(&fc->pending))
goto err_unlock;
req = list_entry(fc->pending.next, struct fuse_req, list);
- list_del_init(&req->list);
+ req->state = FUSE_REQ_READING;
+ list_move(&req->list, &fc->io);
in = &req->in;
reqsize = in->h.len;
if (!req->isreply)
request_end(fc, req);
else {
- req->sent = 1;
- list_add_tail(&req->list, &fc->processing);
+ req->state = FUSE_REQ_SENT;
+ list_move_tail(&req->list, &fc->processing);
spin_unlock(&fuse_lock);
}
return reqsize;
goto err_finish;
spin_lock(&fuse_lock);
+ err = -ENOENT;
+ if (!fc->connected)
+ goto err_unlock;
+
req = request_find(fc, oh.unique);
err = -EINVAL;
if (!req)
goto err_unlock;
- list_del_init(&req->list);
if (req->interrupted) {
- request_end(fc, req);
+ spin_unlock(&fuse_lock);
fuse_copy_finish(&cs);
+ spin_lock(&fuse_lock);
+ request_end(fc, req);
return -ENOENT;
}
+ list_move(&req->list, &fc->io);
req->out.h = oh;
req->locked = 1;
cs.req = req;
return mask;
}
-/* Abort all requests on the given list (pending or processing) */
+/*
+ * Abort all requests on the given list (pending or processing)
+ *
+ * This function releases and reacquires fuse_lock
+ */
static void end_requests(struct fuse_conn *fc, struct list_head *head)
{
while (!list_empty(head)) {
struct fuse_req *req;
req = list_entry(head->next, struct fuse_req, list);
- list_del_init(&req->list);
req->out.h.error = -ECONNABORTED;
request_end(fc, req);
spin_lock(&fuse_lock);
}
}
+/*
+ * Abort requests under I/O
+ *
+ * The requests are set to interrupted and finished, and the request
+ * waiter is woken up. This will make request_wait_answer() wait
+ * until the request is unlocked and then return.
+ *
+ * If the request is asynchronous, then the end function needs to be
+ * called after waiting for the request to be unlocked (if it was
+ * locked).
+ */
+static void end_io_requests(struct fuse_conn *fc)
+{
+ while (!list_empty(&fc->io)) {
+ struct fuse_req *req =
+ list_entry(fc->io.next, struct fuse_req, list);
+ void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
+
+ req->interrupted = 1;
+ req->out.h.error = -ECONNABORTED;
+ req->state = FUSE_REQ_FINISHED;
+ list_del_init(&req->list);
+ wake_up(&req->waitq);
+ if (end) {
+ req->end = NULL;
+ /* The end function will consume this reference */
+ __fuse_get_request(req);
+ spin_unlock(&fuse_lock);
+ wait_event(req->waitq, !req->locked);
+ end(fc, req);
+ spin_lock(&fuse_lock);
+ }
+ }
+}
+
+/*
+ * Abort all requests.
+ *
+ * Emergency exit in case of a malicious or accidental deadlock, or
+ * just a hung filesystem.
+ *
+ * The same effect is usually achievable through killing the
+ * filesystem daemon and all users of the filesystem. The exception
+ * is the combination of an asynchronous request and the tricky
+ * deadlock (see Documentation/filesystems/fuse.txt).
+ *
+ * During the aborting, progression of requests from the pending and
+ * processing lists onto the io list, and progression of new requests
+ * onto the pending list is prevented by req->connected being false.
+ *
+ * Progression of requests under I/O to the processing list is
+ * prevented by the req->interrupted flag being true for these
+ * requests. For this reason requests on the io list must be aborted
+ * first.
+ */
+void fuse_abort_conn(struct fuse_conn *fc)
+{
+ spin_lock(&fuse_lock);
+ if (fc->connected) {
+ fc->connected = 0;
+ end_io_requests(fc);
+ end_requests(fc, &fc->pending);
+ end_requests(fc, &fc->processing);
+ wake_up_all(&fc->waitq);
+ }
+ spin_unlock(&fuse_lock);
+}
+
static int fuse_dev_release(struct inode *inode, struct file *file)
{
struct fuse_conn *fc;
fc->connected = 0;
end_requests(fc, &fc->pending);
end_requests(fc, &fc->processing);
- fuse_release_conn(fc);
}
spin_unlock(&fuse_lock);
+ if (fc)
+ kobject_put(&fc->kobj);
+
return 0;
}
projects / linux-2.6-omap-h63xx.git / blobdiff