MODULE_ALIAS_MISCDEV(FUSE_MINOR);
-static kmem_cache_t *fuse_req_cachep;
+static struct kmem_cache *fuse_req_cachep;
static struct fuse_conn *fuse_get_conn(struct file *file)
{
{
memset(req, 0, sizeof(*req));
INIT_LIST_HEAD(&req->list);
+ INIT_LIST_HEAD(&req->intr_entry);
init_waitqueue_head(&req->waitq);
atomic_set(&req->count, 1);
}
struct fuse_req *fuse_request_alloc(void)
{
- struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, SLAB_KERNEL);
+ struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
if (req)
fuse_request_init(req);
return req;
atomic_dec(&req->count);
}
+static void fuse_req_init_context(struct fuse_req *req)
+{
+ req->in.h.uid = current->fsuid;
+ req->in.h.gid = current->fsgid;
+ req->in.h.pid = current->pid;
+}
+
struct fuse_req *fuse_get_req(struct fuse_conn *fc)
{
struct fuse_req *req;
if (!req)
goto out;
- req->in.h.uid = current->fsuid;
- req->in.h.gid = current->fsgid;
- req->in.h.pid = current->pid;
+ fuse_req_init_context(req);
req->waiting = 1;
return req;
return ERR_PTR(err);
}
+/*
+ * Return request in fuse_file->reserved_req. However that may
+ * currently be in use. If that is the case, wait for it to become
+ * available.
+ */
+static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
+ struct file *file)
+{
+ struct fuse_req *req = NULL;
+ struct fuse_file *ff = file->private_data;
+
+ do {
+ wait_event(fc->blocked_waitq, ff->reserved_req);
+ spin_lock(&fc->lock);
+ if (ff->reserved_req) {
+ req = ff->reserved_req;
+ ff->reserved_req = NULL;
+ get_file(file);
+ req->stolen_file = file;
+ }
+ spin_unlock(&fc->lock);
+ } while (!req);
+
+ return req;
+}
+
+/*
+ * Put stolen request back into fuse_file->reserved_req
+ */
+static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
+{
+ struct file *file = req->stolen_file;
+ struct fuse_file *ff = file->private_data;
+
+ spin_lock(&fc->lock);
+ fuse_request_init(req);
+ BUG_ON(ff->reserved_req);
+ ff->reserved_req = req;
+ wake_up(&fc->blocked_waitq);
+ spin_unlock(&fc->lock);
+ fput(file);
+}
+
+/*
+ * Gets a requests for a file operation, always succeeds
+ *
+ * This is used for sending the FLUSH request, which must get to
+ * userspace, due to POSIX locks which may need to be unlocked.
+ *
+ * If allocation fails due to OOM, use the reserved request in
+ * fuse_file.
+ *
+ * This is very unlikely to deadlock accidentally, since the
+ * filesystem should not have it's own file open. If deadlock is
+ * intentional, it can still be broken by "aborting" the filesystem.
+ */
+struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
+{
+ struct fuse_req *req;
+
+ atomic_inc(&fc->num_waiting);
+ wait_event(fc->blocked_waitq, !fc->blocked);
+ req = fuse_request_alloc();
+ if (!req)
+ req = get_reserved_req(fc, file);
+
+ fuse_req_init_context(req);
+ req->waiting = 1;
+ return req;
+}
+
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
{
if (atomic_dec_and_test(&req->count)) {
if (req->waiting)
atomic_dec(&fc->num_waiting);
- fuse_request_free(req);
+
+ if (req->stolen_file)
+ put_reserved_req(fc, req);
+ else
+ fuse_request_free(req);
}
}
/*
* 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
+ * has arrived or it was aborted (and not yet sent) or some error
* occurred during communication with userspace, or the device file
* was closed. The requester thread is woken up (if still waiting),
* the 'end' callback is called if given, else the reference to the
* Called with fc->lock, unlocks it
*/
static void request_end(struct fuse_conn *fc, struct fuse_req *req)
+ __releases(fc->lock)
{
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
req->end = NULL;
list_del(&req->list);
+ list_del(&req->intr_entry);
req->state = FUSE_REQ_FINISHED;
if (req->background) {
if (fc->num_background == FUSE_MAX_BACKGROUND) {
fuse_put_request(fc, req);
}
+static void wait_answer_interruptible(struct fuse_conn *fc,
+ struct fuse_req *req)
+{
+ if (signal_pending(current))
+ return;
+
+ spin_unlock(&fc->lock);
+ wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
+ spin_lock(&fc->lock);
+}
+
+static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
+{
+ list_add_tail(&req->intr_entry, &fc->interrupts);
+ wake_up(&fc->waitq);
+ kill_fasync(&fc->fasync, SIGIO, POLL_IN);
+}
+
/* Called with fc->lock held. Releases, and then reacquires it. */
static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
{
- sigset_t oldset;
+ if (!fc->no_interrupt) {
+ /* Any signal may interrupt this */
+ wait_answer_interruptible(fc, req);
- spin_unlock(&fc->lock);
- if (req->force)
+ if (req->aborted)
+ goto aborted;
+ if (req->state == FUSE_REQ_FINISHED)
+ return;
+
+ req->interrupted = 1;
+ if (req->state == FUSE_REQ_SENT)
+ queue_interrupt(fc, req);
+ }
+
+ if (req->force) {
+ spin_unlock(&fc->lock);
wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
- else {
+ spin_lock(&fc->lock);
+ } else {
+ sigset_t oldset;
+
+ /* Only fatal signals may interrupt this */
block_sigs(&oldset);
- wait_event_interruptible(req->waitq,
- req->state == FUSE_REQ_FINISHED);
+ wait_answer_interruptible(fc, req);
restore_sigs(&oldset);
}
- spin_lock(&fc->lock);
- if (req->state == FUSE_REQ_FINISHED && !req->interrupted)
- return;
- if (!req->interrupted) {
- req->out.h.error = -EINTR;
- req->interrupted = 1;
- }
+ if (req->aborted)
+ goto aborted;
+ if (req->state == FUSE_REQ_FINISHED)
+ return;
+
+ req->out.h.error = -EINTR;
+ req->aborted = 1;
+
+ aborted:
if (req->locked) {
/* This is uninterruptible sleep, because data is
being copied to/from the buffers of req. During
return nbytes;
}
+static u64 fuse_get_unique(struct fuse_conn *fc)
+ {
+ fc->reqctr++;
+ /* zero is special */
+ if (fc->reqctr == 0)
+ fc->reqctr = 1;
+
+ return fc->reqctr;
+}
+
static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
{
- fc->reqctr++;
- /* zero is special */
- if (fc->reqctr == 0)
- fc->reqctr = 1;
- req->in.h.unique = fc->reqctr;
+ req->in.h.unique = fuse_get_unique(fc);
req->in.h.len = sizeof(struct fuse_in_header) +
len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
list_add_tail(&req->list, &fc->pending);
kill_fasync(&fc->fasync, SIGIO, POLL_IN);
}
-/*
- * This can only be interrupted by a SIGKILL
- */
void request_send(struct fuse_conn *fc, struct fuse_req *req)
{
req->isreply = 1;
/*
* 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.
+ * aborted bail out.
*/
static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
{
int err = 0;
if (req) {
spin_lock(&fc->lock);
- if (req->interrupted)
+ if (req->aborted)
err = -ENOENT;
else
req->locked = 1;
}
/*
- * Unlock request. If it was interrupted during being locked, the
+ * Unlock request. If it was aborted during being locked, the
* requester thread is currently waiting for it to be unlocked, so
* wake it up.
*/
if (req) {
spin_lock(&fc->lock);
req->locked = 0;
- if (req->interrupted)
+ if (req->aborted)
wake_up(&req->waitq);
spin_unlock(&fc->lock);
}
return err;
}
+static int request_pending(struct fuse_conn *fc)
+{
+ return !list_empty(&fc->pending) || !list_empty(&fc->interrupts);
+}
+
/* Wait until a request is available on the pending list */
static void request_wait(struct fuse_conn *fc)
{
DECLARE_WAITQUEUE(wait, current);
add_wait_queue_exclusive(&fc->waitq, &wait);
- while (fc->connected && list_empty(&fc->pending)) {
+ while (fc->connected && !request_pending(fc)) {
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current))
break;
remove_wait_queue(&fc->waitq, &wait);
}
+/*
+ * Transfer an interrupt request to userspace
+ *
+ * Unlike other requests this is assembled on demand, without a need
+ * to allocate a separate fuse_req structure.
+ *
+ * Called with fc->lock held, releases it
+ */
+static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_req *req,
+ const struct iovec *iov, unsigned long nr_segs)
+ __releases(fc->lock)
+{
+ struct fuse_copy_state cs;
+ struct fuse_in_header ih;
+ struct fuse_interrupt_in arg;
+ unsigned reqsize = sizeof(ih) + sizeof(arg);
+ int err;
+
+ list_del_init(&req->intr_entry);
+ req->intr_unique = fuse_get_unique(fc);
+ memset(&ih, 0, sizeof(ih));
+ memset(&arg, 0, sizeof(arg));
+ ih.len = reqsize;
+ ih.opcode = FUSE_INTERRUPT;
+ ih.unique = req->intr_unique;
+ arg.unique = req->in.h.unique;
+
+ spin_unlock(&fc->lock);
+ if (iov_length(iov, nr_segs) < reqsize)
+ return -EINVAL;
+
+ fuse_copy_init(&cs, fc, 1, NULL, iov, nr_segs);
+ err = fuse_copy_one(&cs, &ih, sizeof(ih));
+ if (!err)
+ err = fuse_copy_one(&cs, &arg, sizeof(arg));
+ fuse_copy_finish(&cs);
+
+ return err ? err : reqsize;
+}
+
/*
* Read a single request into the userspace filesystem's buffer. This
* function waits until a request is available, then removes it from
* the pending list and copies request data to userspace buffer. If
- * no reply is needed (FORGET) or request has been interrupted or
- * there was an error during the copying then it's finished by calling
+ * no reply is needed (FORGET) or request has been aborted or there
+ * was an error during the copying then it's finished by calling
* request_end(). Otherwise add it to the processing list, and set
* the 'sent' flag.
*/
-static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *off)
+static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
int err;
struct fuse_req *req;
struct fuse_in *in;
struct fuse_copy_state cs;
unsigned reqsize;
+ struct file *file = iocb->ki_filp;
struct fuse_conn *fc = fuse_get_conn(file);
if (!fc)
return -EPERM;
spin_lock(&fc->lock);
err = -EAGAIN;
if ((file->f_flags & O_NONBLOCK) && fc->connected &&
- list_empty(&fc->pending))
+ !request_pending(fc))
goto err_unlock;
request_wait(fc);
if (!fc->connected)
goto err_unlock;
err = -ERESTARTSYS;
- if (list_empty(&fc->pending))
+ if (!request_pending(fc))
goto err_unlock;
+ if (!list_empty(&fc->interrupts)) {
+ req = list_entry(fc->interrupts.next, struct fuse_req,
+ intr_entry);
+ return fuse_read_interrupt(fc, req, iov, nr_segs);
+ }
+
req = list_entry(fc->pending.next, struct fuse_req, list);
req->state = FUSE_REQ_READING;
list_move(&req->list, &fc->io);
fuse_copy_finish(&cs);
spin_lock(&fc->lock);
req->locked = 0;
- if (!err && req->interrupted)
+ if (!err && req->aborted)
err = -ENOENT;
if (err) {
- if (!req->interrupted)
+ if (!req->aborted)
req->out.h.error = -EIO;
request_end(fc, req);
return err;
else {
req->state = FUSE_REQ_SENT;
list_move_tail(&req->list, &fc->processing);
+ if (req->interrupted)
+ queue_interrupt(fc, req);
spin_unlock(&fc->lock);
}
return reqsize;
return err;
}
-static ssize_t fuse_dev_read(struct file *file, char __user *buf,
- size_t nbytes, loff_t *off)
-{
- struct iovec iov;
- iov.iov_len = nbytes;
- iov.iov_base = buf;
- return fuse_dev_readv(file, &iov, 1, off);
-}
-
/* Look up request on processing list by unique ID */
static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
{
list_for_each(entry, &fc->processing) {
struct fuse_req *req;
req = list_entry(entry, struct fuse_req, list);
- if (req->in.h.unique == unique)
+ if (req->in.h.unique == unique || req->intr_unique == unique)
return req;
}
return NULL;
* it from the list and copy the rest of the buffer to the request.
* The request is finished by calling request_end()
*/
-static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *off)
+static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
int err;
unsigned nbytes = iov_length(iov, nr_segs);
struct fuse_req *req;
struct fuse_out_header oh;
struct fuse_copy_state cs;
- struct fuse_conn *fc = fuse_get_conn(file);
+ struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
if (!fc)
return -EPERM;
goto err_unlock;
req = request_find(fc, oh.unique);
- err = -EINVAL;
if (!req)
goto err_unlock;
- if (req->interrupted) {
+ if (req->aborted) {
spin_unlock(&fc->lock);
fuse_copy_finish(&cs);
spin_lock(&fc->lock);
request_end(fc, req);
return -ENOENT;
}
+ /* Is it an interrupt reply? */
+ if (req->intr_unique == oh.unique) {
+ err = -EINVAL;
+ if (nbytes != sizeof(struct fuse_out_header))
+ goto err_unlock;
+
+ if (oh.error == -ENOSYS)
+ fc->no_interrupt = 1;
+ else if (oh.error == -EAGAIN)
+ queue_interrupt(fc, req);
+
+ spin_unlock(&fc->lock);
+ fuse_copy_finish(&cs);
+ return nbytes;
+ }
+
+ req->state = FUSE_REQ_WRITING;
list_move(&req->list, &fc->io);
req->out.h = oh;
req->locked = 1;
spin_lock(&fc->lock);
req->locked = 0;
if (!err) {
- if (req->interrupted)
+ if (req->aborted)
err = -ENOENT;
- } else if (!req->interrupted)
+ } else if (!req->aborted)
req->out.h.error = -EIO;
request_end(fc, req);
return err;
}
-static ssize_t fuse_dev_write(struct file *file, const char __user *buf,
- size_t nbytes, loff_t *off)
-{
- struct iovec iov;
- iov.iov_len = nbytes;
- iov.iov_base = (char __user *) buf;
- return fuse_dev_writev(file, &iov, 1, off);
-}
-
static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
{
unsigned mask = POLLOUT | POLLWRNORM;
spin_lock(&fc->lock);
if (!fc->connected)
mask = POLLERR;
- else if (!list_empty(&fc->pending))
+ else if (request_pending(fc))
mask |= POLLIN | POLLRDNORM;
spin_unlock(&fc->lock);
/*
* Abort requests under I/O
*
- * The requests are set to interrupted and finished, and the request
+ * The requests are set to aborted and finished, and the request
* waiter is woken up. This will make request_wait_answer() wait
* until the request is unlocked and then return.
*
list_entry(fc->io.next, struct fuse_req, list);
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
- req->interrupted = 1;
+ req->aborted = 1;
req->out.h.error = -ECONNABORTED;
req->state = FUSE_REQ_FINISHED;
list_del_init(&req->list);
* 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.
+ * prevented by the req->aborted 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)
{
const struct file_operations fuse_dev_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
- .read = fuse_dev_read,
- .readv = fuse_dev_readv,
- .write = fuse_dev_write,
- .writev = fuse_dev_writev,
+ .read = do_sync_read,
+ .aio_read = fuse_dev_read,
+ .write = do_sync_write,
+ .aio_write = fuse_dev_write,
.poll = fuse_dev_poll,
.release = fuse_dev_release,
.fasync = fuse_dev_fasync,