| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/poll.h> |
| #include <linux/uio.h> |
| #include <linux/miscdevice.h> |
| #include <linux/pagemap.h> |
| #include <linux/file.h> |
| #include <linux/slab.h> |
| |
| static kmem_cache_t *fuse_req_cachep; |
| |
| static inline struct fuse_conn *fuse_get_conn(struct file *file) |
| { |
| struct fuse_conn *fc; |
| spin_lock(&fuse_lock); |
| fc = file->private_data; |
| if (fc && !fc->sb) |
| fc = NULL; |
| spin_unlock(&fuse_lock); |
| return fc; |
| } |
| |
| static inline void fuse_request_init(struct fuse_req *req) |
| { |
| memset(req, 0, sizeof(*req)); |
| INIT_LIST_HEAD(&req->list); |
| 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); |
| if (req) |
| fuse_request_init(req); |
| return req; |
| } |
| |
| void fuse_request_free(struct fuse_req *req) |
| { |
| kmem_cache_free(fuse_req_cachep, req); |
| } |
| |
| #ifdef KERNEL_2_6 |
| static inline void block_sigs(sigset_t *oldset) |
| { |
| sigset_t mask; |
| |
| siginitsetinv(&mask, sigmask(SIGKILL)); |
| sigprocmask(SIG_BLOCK, &mask, oldset); |
| } |
| |
| static inline void restore_sigs(sigset_t *oldset) |
| { |
| sigprocmask(SIG_SETMASK, oldset, NULL); |
| } |
| #else |
| static inline void block_sigs(sigset_t *oldset) |
| { |
| spin_lock_irq(¤t->sigmask_lock); |
| *oldset = current->blocked; |
| siginitsetinv(¤t->blocked, sigmask(SIGKILL) & ~oldset->sig[0]); |
| recalc_sigpending(current); |
| spin_unlock_irq(¤t->sigmask_lock); |
| } |
| |
| static inline void restore_sigs(sigset_t *oldset) |
| { |
| spin_lock_irq(¤t->sigmask_lock); |
| current->blocked = *oldset; |
| recalc_sigpending(current); |
| spin_unlock_irq(¤t->sigmask_lock); |
| } |
| #endif |
| |
| void fuse_reset_request(struct fuse_req *req) |
| { |
| int preallocated = req->preallocated; |
| BUG_ON(atomic_read(&req->count) != 1); |
| fuse_request_init(req); |
| req->preallocated = preallocated; |
| } |
| |
| static void __fuse_get_request(struct fuse_req *req) |
| { |
| atomic_inc(&req->count); |
| } |
| |
| /* Must be called with > 1 refcount */ |
| static void __fuse_put_request(struct fuse_req *req) |
| { |
| BUG_ON(atomic_read(&req->count) < 2); |
| atomic_dec(&req->count); |
| } |
| |
| static struct fuse_req *do_get_request(struct fuse_conn *fc) |
| { |
| struct fuse_req *req; |
| |
| spin_lock(&fuse_lock); |
| BUG_ON(list_empty(&fc->unused_list)); |
| req = list_entry(fc->unused_list.next, struct fuse_req, list); |
| list_del_init(&req->list); |
| spin_unlock(&fuse_lock); |
| fuse_request_init(req); |
| req->preallocated = 1; |
| req->in.h.uid = current->fsuid; |
| req->in.h.gid = current->fsgid; |
| req->in.h.pid = current->pid; |
| return req; |
| } |
| |
| struct fuse_req *fuse_get_request(struct fuse_conn *fc) |
| { |
| if (down_interruptible(&fc->outstanding_sem)) |
| return NULL; |
| return do_get_request(fc); |
| } |
| |
| struct fuse_req *fuse_get_request_nonint(struct fuse_conn *fc) |
| { |
| int intr; |
| sigset_t oldset; |
| |
| block_sigs(&oldset); |
| intr = down_interruptible(&fc->outstanding_sem); |
| restore_sigs(&oldset); |
| return intr ? NULL : do_get_request(fc); |
| } |
| |
| static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| if (!req->preallocated) |
| fuse_request_free(req); |
| |
| spin_lock(&fuse_lock); |
| if (req->preallocated) |
| list_add(&req->list, &fc->unused_list); |
| |
| if (fc->outstanding_debt) |
| 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)) |
| fuse_putback_request(fc, req); |
| } |
| |
| /* 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) { |
| if (req->inode) |
| iput(req->inode); |
| if (req->inode2) |
| iput(req->inode2); |
| if (req->file) |
| fput(req->file); |
| } |
| wake_up(&req->waitq); |
| if (req->in.h.opcode == FUSE_INIT) { |
| int i; |
| /* 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); |
| } |
| if (putback) |
| fuse_putback_request(fc, req); |
| } |
| |
| static void background_request(struct fuse_req *req) |
| { |
| /* Need to get hold of the inode(s) and/or file used in the |
| request, so FORGET and RELEASE are not sent too early */ |
| req->background = 1; |
| if (req->inode) |
| req->inode = igrab(req->inode); |
| if (req->inode2) |
| req->inode2 = igrab(req->inode2); |
| if (req->file) |
| get_file(req->file); |
| } |
| |
| static int request_wait_answer_nonint(struct fuse_req *req) |
| { |
| int err; |
| sigset_t oldset; |
| block_sigs(&oldset); |
| err = wait_event_interruptible(req->waitq, req->finished); |
| restore_sigs(&oldset); |
| return err; |
| } |
| |
| /* Called with fuse_lock held. Releases, and then reacquires it. */ |
| static void request_wait_answer(struct fuse_req *req, int interruptible) |
| { |
| int intr; |
| |
| spin_unlock(&fuse_lock); |
| if (interruptible) |
| intr = wait_event_interruptible(req->waitq, req->finished); |
| else |
| intr = request_wait_answer_nonint(req); |
| spin_lock(&fuse_lock); |
| if (intr && interruptible && req->sent) { |
| /* If request is already in userspace, only allow KILL |
| signal to interrupt */ |
| spin_unlock(&fuse_lock); |
| intr = request_wait_answer_nonint(req); |
| spin_lock(&fuse_lock); |
| } |
| if (!intr) |
| return; |
| |
| if (!interruptible || req->sent) |
| req->out.h.error = -EINTR; |
| else |
| req->out.h.error = -ERESTARTNOINTR; |
| |
| req->interrupted = 1; |
| if (req->locked) { |
| /* This is uninterruptible sleep, because data is |
| being copied to/from the buffers of req. During |
| locked state, there musn't be any filesystem |
| operation (e.g. page fault), since that could lead |
| to deadlock */ |
| spin_unlock(&fuse_lock); |
| wait_event(req->waitq, !req->locked); |
| spin_lock(&fuse_lock); |
| } |
| if (!req->sent && !list_empty(&req->list)) { |
| list_del(&req->list); |
| __fuse_put_request(req); |
| } else if (req->sent) |
| background_request(req); |
| } |
| |
| static unsigned len_args(unsigned numargs, struct fuse_arg *args) |
| { |
| unsigned nbytes = 0; |
| unsigned i; |
| |
| for (i = 0; i < numargs; i++) |
| nbytes += args[i].size; |
| |
| return nbytes; |
| } |
| |
| 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.len = sizeof(struct fuse_in_header) + |
| len_args(req->in.numargs, (struct fuse_arg *) req->in.args); |
| if (!req->preallocated) { |
| /* decrease outstanding_sem, but without blocking... */ |
| if (down_trylock(&fc->outstanding_sem)) |
| fc->outstanding_debt++; |
| } |
| list_add_tail(&req->list, &fc->pending); |
| wake_up(&fc->waitq); |
| } |
| |
| static void request_send_wait(struct fuse_conn *fc, struct fuse_req *req, |
| int interruptible) |
| { |
| req->isreply = 1; |
| spin_lock(&fuse_lock); |
| req->out.h.error = -ENOTCONN; |
| if (fc->file) { |
| queue_request(fc, req); |
| /* acquire extra reference, since request is still needed |
| after request_end() */ |
| __fuse_get_request(req); |
| |
| request_wait_answer(req, interruptible); |
| } |
| spin_unlock(&fuse_lock); |
| } |
| |
| void request_send(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| request_send_wait(fc, req, 1); |
| } |
| |
| void request_send_nonint(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| request_send_wait(fc, req, 0); |
| } |
| |
| static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| spin_lock(&fuse_lock); |
| if (fc->file) { |
| queue_request(fc, req); |
| spin_unlock(&fuse_lock); |
| } else { |
| req->out.h.error = -ENOTCONN; |
| request_end(fc, req); |
| } |
| } |
| |
| void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| req->isreply = 0; |
| request_send_nowait(fc, req); |
| } |
| |
| void request_send_background(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| req->isreply = 1; |
| background_request(req); |
| 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_out *arg = &req->misc.init_in_out; |
| 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; |
| req->out.args[0].size = sizeof(*arg); |
| req->out.args[0].value = arg; |
| request_send_background(fc, req); |
| } |
| |
| static inline int lock_request(struct fuse_req *req) |
| { |
| int err = 0; |
| if (req) { |
| spin_lock(&fuse_lock); |
| if (req->interrupted) |
| err = -ENOENT; |
| else |
| req->locked = 1; |
| spin_unlock(&fuse_lock); |
| } |
| return err; |
| } |
| |
| static inline void unlock_request(struct fuse_req *req) |
| { |
| if (req) { |
| spin_lock(&fuse_lock); |
| req->locked = 0; |
| if (req->interrupted) |
| wake_up(&req->waitq); |
| spin_unlock(&fuse_lock); |
| } |
| } |
| |
| /* Why all this complex one-page-at-a-time copying needed instead of |
| just copy_to/from_user()? The reason is that blocking on a page |
| fault must be avoided while the request is locked. This is because |
| if servicing that pagefault happens to be done by this filesystem, |
| an unbreakable deadlock can occur. So the code is careful to allow |
| request interruption during get_user_pages(), and only lock the |
| request while doing kmapped copying, which cannot block. |
| */ |
| |
| struct fuse_copy_state { |
| int write; |
| struct fuse_req *req; |
| const struct iovec *iov; |
| unsigned long nr_segs; |
| unsigned long seglen; |
| unsigned long addr; |
| struct page *pg; |
| void *mapaddr; |
| void *buf; |
| unsigned len; |
| }; |
| |
| static unsigned fuse_copy_init(struct fuse_copy_state *cs, int write, |
| struct fuse_req *req, const struct iovec *iov, |
| unsigned long nr_segs) |
| { |
| unsigned i; |
| unsigned nbytes; |
| |
| memset(cs, 0, sizeof(*cs)); |
| cs->write = write; |
| cs->req = req; |
| cs->iov = iov; |
| cs->nr_segs = nr_segs; |
| |
| nbytes = 0; |
| for (i = 0; i < nr_segs; i++) |
| nbytes += iov[i].iov_len; |
| |
| return nbytes; |
| } |
| |
| static inline void fuse_copy_finish(struct fuse_copy_state *cs) |
| { |
| if (cs->mapaddr) { |
| kunmap_atomic(cs->mapaddr, KM_USER0); |
| if (cs->write) { |
| flush_dcache_page(cs->pg); |
| set_page_dirty_lock(cs->pg); |
| } |
| put_page(cs->pg); |
| cs->mapaddr = NULL; |
| } |
| } |
| |
| static int fuse_copy_fill(struct fuse_copy_state *cs) |
| { |
| unsigned long offset; |
| int err; |
| |
| unlock_request(cs->req); |
| fuse_copy_finish(cs); |
| if (!cs->seglen) { |
| BUG_ON(!cs->nr_segs); |
| cs->seglen = cs->iov[0].iov_len; |
| cs->addr = (unsigned long) cs->iov[0].iov_base; |
| cs->iov ++; |
| cs->nr_segs --; |
| } |
| down_read(¤t->mm->mmap_sem); |
| err = get_user_pages(current, current->mm, cs->addr, 1, cs->write, 0, |
| &cs->pg, NULL); |
| up_read(¤t->mm->mmap_sem); |
| if (err < 0) |
| return err; |
| BUG_ON(err != 1); |
| offset = cs->addr % PAGE_SIZE; |
| cs->mapaddr = kmap_atomic(cs->pg, KM_USER0); |
| cs->buf = cs->mapaddr + offset; |
| cs->len = min(PAGE_SIZE - offset, cs->seglen); |
| cs->seglen -= cs->len; |
| cs->addr += cs->len; |
| |
| return lock_request(cs->req); |
| } |
| |
| static inline int fuse_copy_do(struct fuse_copy_state *cs, void **val, |
| unsigned *size) |
| { |
| unsigned ncpy = min(*size, cs->len); |
| if (val) { |
| if (cs->write) |
| memcpy(cs->buf, *val, ncpy); |
| else |
| memcpy(*val, cs->buf, ncpy); |
| *val += ncpy; |
| } |
| *size -= ncpy; |
| cs->len -= ncpy; |
| cs->buf += ncpy; |
| return ncpy; |
| } |
| |
| static inline 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); |
| memset(mapaddr, 0, PAGE_SIZE); |
| kunmap_atomic(mapaddr, KM_USER1); |
| } |
| while (count) { |
| int err; |
| if (!cs->len && (err = fuse_copy_fill(cs))) |
| return err; |
| if (page) { |
| void *mapaddr = kmap_atomic(page, KM_USER1); |
| void *buf = mapaddr + offset; |
| offset += fuse_copy_do(cs, &buf, &count); |
| kunmap_atomic(mapaddr, KM_USER1); |
| } else |
| offset += fuse_copy_do(cs, NULL, &count); |
| } |
| if (page && !cs->write) |
| flush_dcache_page(page); |
| return 0; |
| } |
| |
| static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, |
| int zeroing) |
| { |
| unsigned i; |
| struct fuse_req *req = cs->req; |
| unsigned offset = req->page_offset; |
| unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset); |
| |
| for (i = 0; i < req->num_pages && nbytes; i++) { |
| struct page *page = req->pages[i]; |
| int err = fuse_copy_page(cs, page, offset, count, zeroing); |
| if (err) |
| return err; |
| |
| nbytes -= count; |
| count = min(nbytes, (unsigned) PAGE_SIZE); |
| offset = 0; |
| } |
| return 0; |
| } |
| |
| static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size) |
| { |
| while (size) { |
| int err; |
| if (!cs->len && (err = fuse_copy_fill(cs))) |
| return err; |
| fuse_copy_do(cs, &val, &size); |
| } |
| return 0; |
| } |
| |
| static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs, |
| unsigned argpages, struct fuse_arg *args, |
| int zeroing) |
| { |
| int err = 0; |
| unsigned i; |
| |
| for (i = 0; !err && i < numargs; i++) { |
| struct fuse_arg *arg = &args[i]; |
| if (i == numargs - 1 && argpages) |
| err = fuse_copy_pages(cs, arg->size, zeroing); |
| else |
| err = fuse_copy_one(cs, arg->value, arg->size); |
| } |
| return err; |
| } |
| |
| static void request_wait(struct fuse_conn *fc) |
| { |
| DECLARE_WAITQUEUE(wait, current); |
| |
| add_wait_queue_exclusive(&fc->waitq, &wait); |
| while (fc->sb && list_empty(&fc->pending)) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| if (signal_pending(current)) |
| break; |
| |
| spin_unlock(&fuse_lock); |
| schedule(); |
| spin_lock(&fuse_lock); |
| } |
| set_current_state(TASK_RUNNING); |
| remove_wait_queue(&fc->waitq, &wait); |
| } |
| |
| static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, |
| unsigned long nr_segs, loff_t *off) |
| { |
| int err; |
| struct fuse_conn *fc; |
| struct fuse_req *req; |
| struct fuse_in *in; |
| struct fuse_copy_state cs; |
| unsigned nbytes; |
| unsigned reqsize; |
| |
| spin_lock(&fuse_lock); |
| fc = file->private_data; |
| err = -EPERM; |
| if (!fc) |
| goto err_unlock; |
| request_wait(fc); |
| err = -ENODEV; |
| if (!fc->sb) |
| 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); |
| spin_unlock(&fuse_lock); |
| |
| in = &req->in; |
| reqsize = req->in.h.len; |
| nbytes = fuse_copy_init(&cs, 1, req, iov, nr_segs); |
| err = -EINVAL; |
| if (nbytes >= reqsize) { |
| err = fuse_copy_one(&cs, &in->h, sizeof(in->h)); |
| if (!err) |
| err = fuse_copy_args(&cs, in->numargs, in->argpages, |
| (struct fuse_arg *) in->args, 0); |
| } |
| fuse_copy_finish(&cs); |
| |
| spin_lock(&fuse_lock); |
| req->locked = 0; |
| if (!err && req->interrupted) |
| err = -ENOENT; |
| if (err) { |
| if (!req->interrupted) |
| req->out.h.error = -EIO; |
| request_end(fc, req); |
| return err; |
| } |
| if (!req->isreply) |
| request_end(fc, req); |
| else { |
| req->sent = 1; |
| list_add_tail(&req->list, &fc->processing); |
| spin_unlock(&fuse_lock); |
| } |
| return reqsize; |
| |
| err_unlock: |
| spin_unlock(&fuse_lock); |
| 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); |
| } |
| |
| static struct fuse_req *request_find(struct fuse_conn *fc, unsigned unique) |
| { |
| struct list_head *entry; |
| |
| list_for_each(entry, &fc->processing) { |
| struct fuse_req *req; |
| req = list_entry(entry, struct fuse_req, list); |
| if (req->in.h.unique == unique) |
| return req; |
| } |
| return NULL; |
| } |
| |
| /* fget() needs to be done in this context */ |
| static void process_getdir(struct fuse_req *req) |
| { |
| struct fuse_getdir_out_i *arg = req->out.args[0].value; |
| arg->file = fget(arg->fd); |
| } |
| |
| static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out, |
| unsigned nbytes) |
| { |
| unsigned reqsize = sizeof(struct fuse_out_header); |
| |
| if (out->h.error) |
| return nbytes != reqsize ? -EINVAL : 0; |
| |
| reqsize += len_args(out->numargs, out->args); |
| |
| if (reqsize < nbytes || (reqsize > nbytes && !out->argvar)) |
| return -EINVAL; |
| else if (reqsize > nbytes) { |
| struct fuse_arg *lastarg = &out->args[out->numargs-1]; |
| unsigned diffsize = reqsize - nbytes; |
| if (diffsize > lastarg->size) |
| return -EINVAL; |
| lastarg->size -= diffsize; |
| } |
| return fuse_copy_args(cs, out->numargs, out->argpages, out->args, |
| out->page_zeroing); |
| } |
| |
| static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, |
| unsigned long nr_segs, loff_t *off) |
| { |
| int err; |
| unsigned nbytes; |
| struct fuse_req *req; |
| struct fuse_out_header oh; |
| struct fuse_copy_state cs; |
| struct fuse_conn *fc = fuse_get_conn(file); |
| if (!fc) |
| return -ENODEV; |
| |
| nbytes = fuse_copy_init(&cs, 0, NULL, iov, nr_segs); |
| if (nbytes < sizeof(struct fuse_out_header)) |
| return -EINVAL; |
| |
| err = fuse_copy_one(&cs, &oh, sizeof(oh)); |
| if (err) |
| goto err_finish; |
| err = -EINVAL; |
| if (!oh.unique || oh.error <= -1000 || oh.error > 0 || |
| oh.len != nbytes) |
| goto err_finish; |
| |
| spin_lock(&fuse_lock); |
| 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); |
| fuse_copy_finish(&cs); |
| return -ENOENT; |
| } |
| req->out.h = oh; |
| req->locked = 1; |
| cs.req = req; |
| spin_unlock(&fuse_lock); |
| |
| err = copy_out_args(&cs, &req->out, nbytes); |
| fuse_copy_finish(&cs); |
| |
| spin_lock(&fuse_lock); |
| req->locked = 0; |
| if (!err) { |
| if (req->interrupted) |
| err = -ENOENT; |
| else if (req->in.h.opcode == FUSE_GETDIR && !oh.error) |
| process_getdir(req); |
| } else if (!req->interrupted) |
| req->out.h.error = -EIO; |
| request_end(fc, req); |
| |
| return err ? err : nbytes; |
| |
| err_unlock: |
| spin_unlock(&fuse_lock); |
| err_finish: |
| fuse_copy_finish(&cs); |
| 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) |
| { |
| struct fuse_conn *fc = fuse_get_conn(file); |
| unsigned mask = POLLOUT | POLLWRNORM; |
| |
| if (!fc) |
| return -ENODEV; |
| |
| poll_wait(file, &fc->waitq, wait); |
| |
| spin_lock(&fuse_lock); |
| if (!list_empty(&fc->pending)) |
| mask |= POLLIN | POLLRDNORM; |
| spin_unlock(&fuse_lock); |
| |
| return mask; |
| } |
| |
| 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); |
| } |
| } |
| |
| static int fuse_dev_release(struct inode *inode, struct file *file) |
| { |
| struct fuse_conn *fc; |
| |
| spin_lock(&fuse_lock); |
| fc = file->private_data; |
| if (fc) { |
| fc->file = NULL; |
| end_requests(fc, &fc->pending); |
| end_requests(fc, &fc->processing); |
| fuse_release_conn(fc); |
| } |
| spin_unlock(&fuse_lock); |
| return 0; |
| } |
| |
| struct file_operations fuse_dev_operations = { |
| .owner = THIS_MODULE, |
| .read = fuse_dev_read, |
| .readv = fuse_dev_readv, |
| .write = fuse_dev_write, |
| .writev = fuse_dev_writev, |
| .poll = fuse_dev_poll, |
| .release = fuse_dev_release, |
| }; |
| |
| static struct miscdevice fuse_miscdevice = { |
| .minor = FUSE_MINOR, |
| .name = "fuse", |
| .fops = &fuse_dev_operations, |
| }; |
| |
| int __init fuse_dev_init(void) |
| { |
| int err = -ENOMEM; |
| fuse_req_cachep = kmem_cache_create("fuse_request", |
| sizeof(struct fuse_req), |
| 0, 0, NULL, NULL); |
| if (!fuse_req_cachep) |
| goto out; |
| |
| err = misc_register(&fuse_miscdevice); |
| if (err) |
| goto out_cache_clean; |
| |
| return 0; |
| |
| out_cache_clean: |
| kmem_cache_destroy(fuse_req_cachep); |
| out: |
| return err; |
| } |
| |
| void fuse_dev_cleanup(void) |
| { |
| misc_deregister(&fuse_miscdevice); |
| kmem_cache_destroy(fuse_req_cachep); |
| } |