diff options
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r-- | fs/fuse/file.c | 457 |
1 files changed, 438 insertions, 19 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 4c9ee701126..e8162646a9b 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1,6 +1,6 @@ /* FUSE: Filesystem in Userspace - Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> + Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> This program can be distributed under the terms of the GNU GPL. See the file COPYING. @@ -39,14 +39,14 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir, req->out.numargs = 1; req->out.args[0].size = sizeof(*outargp); req->out.args[0].value = outargp; - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); return err; } -struct fuse_file *fuse_file_alloc(void) +struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) { struct fuse_file *ff; ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); @@ -58,7 +58,12 @@ struct fuse_file *fuse_file_alloc(void) } else { INIT_LIST_HEAD(&ff->write_entry); atomic_set(&ff->count, 0); + spin_lock(&fc->lock); + ff->kh = ++fc->khctr; + spin_unlock(&fc->lock); } + RB_CLEAR_NODE(&ff->polled_node); + init_waitqueue_head(&ff->poll_wait); } return ff; } @@ -79,7 +84,6 @@ static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req) { dput(req->misc.release.dentry); mntput(req->misc.release.vfsmount); - fuse_put_request(fc, req); } static void fuse_file_put(struct fuse_file *ff) @@ -89,7 +93,7 @@ static void fuse_file_put(struct fuse_file *ff) struct inode *inode = req->misc.release.dentry->d_inode; struct fuse_conn *fc = get_fuse_conn(inode); req->end = fuse_release_end; - request_send_background(fc, req); + fuse_request_send_background(fc, req); kfree(ff); } } @@ -109,6 +113,7 @@ void fuse_finish_open(struct inode *inode, struct file *file, int fuse_open_common(struct inode *inode, struct file *file, int isdir) { + struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_open_out outarg; struct fuse_file *ff; int err; @@ -121,7 +126,7 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir) if (err) return err; - ff = fuse_file_alloc(); + ff = fuse_file_alloc(fc); if (!ff) return -ENOMEM; @@ -167,7 +172,11 @@ int fuse_release_common(struct inode *inode, struct file *file, int isdir) spin_lock(&fc->lock); list_del(&ff->write_entry); + if (!RB_EMPTY_NODE(&ff->polled_node)) + rb_erase(&ff->polled_node, &fc->polled_files); spin_unlock(&fc->lock); + + wake_up_interruptible_sync(&ff->poll_wait); /* * Normally this will send the RELEASE request, * however if some asynchronous READ or WRITE requests @@ -280,7 +289,7 @@ static int fuse_flush(struct file *file, fl_owner_t id) req->in.args[0].size = sizeof(inarg); req->in.args[0].value = &inarg; req->force = 1; - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); if (err == -ENOSYS) { @@ -344,7 +353,7 @@ int fuse_fsync_common(struct file *file, struct dentry *de, int datasync, req->in.numargs = 1; req->in.args[0].size = sizeof(inarg); req->in.args[0].value = &inarg; - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); if (err == -ENOSYS) { @@ -396,7 +405,7 @@ static size_t fuse_send_read(struct fuse_req *req, struct file *file, inarg->read_flags |= FUSE_READ_LOCKOWNER; inarg->lock_owner = fuse_lock_owner_id(fc, owner); } - request_send(fc, req); + fuse_request_send(fc, req); return req->out.args[0].size; } @@ -493,7 +502,6 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) } if (req->ff) fuse_file_put(req->ff); - fuse_put_request(fc, req); } static void fuse_send_readpages(struct fuse_req *req, struct file *file, @@ -509,10 +517,11 @@ static void fuse_send_readpages(struct fuse_req *req, struct file *file, struct fuse_file *ff = file->private_data; req->ff = fuse_file_get(ff); req->end = fuse_readpages_end; - request_send_background(fc, req); + fuse_request_send_background(fc, req); } else { - request_send(fc, req); + fuse_request_send(fc, req); fuse_readpages_end(fc, req); + fuse_put_request(fc, req); } } @@ -543,7 +552,7 @@ static int fuse_readpages_fill(void *_data, struct page *page) } } req->pages[req->num_pages] = page; - req->num_pages ++; + req->num_pages++; return 0; } @@ -636,7 +645,7 @@ static size_t fuse_send_write(struct fuse_req *req, struct file *file, inarg->write_flags |= FUSE_WRITE_LOCKOWNER; inarg->lock_owner = fuse_lock_owner_id(fc, owner); } - request_send(fc, req); + fuse_request_send(fc, req); return req->misc.write.out.size; } @@ -1042,7 +1051,6 @@ static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req) { __free_page(req->pages[0]); fuse_file_put(req->ff); - fuse_put_request(fc, req); } static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) @@ -1060,6 +1068,8 @@ static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) /* Called under fc->lock, may release and reacquire it */ static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req) +__releases(&fc->lock) +__acquires(&fc->lock) { struct fuse_inode *fi = get_fuse_inode(req->inode); loff_t size = i_size_read(req->inode); @@ -1079,13 +1089,14 @@ static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req) req->in.args[1].size = inarg->size; fi->writectr++; - request_send_background_locked(fc, req); + fuse_request_send_background_locked(fc, req); return; out_free: fuse_writepage_finish(fc, req); spin_unlock(&fc->lock); fuse_writepage_free(fc, req); + fuse_put_request(fc, req); spin_lock(&fc->lock); } @@ -1096,6 +1107,8 @@ static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req) * Called with fc->lock */ void fuse_flush_writepages(struct inode *inode) +__releases(&fc->lock) +__acquires(&fc->lock) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); @@ -1325,7 +1338,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl) req->out.numargs = 1; req->out.args[0].size = sizeof(outarg); req->out.args[0].value = &outarg; - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); if (!err) @@ -1357,7 +1370,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) return PTR_ERR(req); fuse_lk_fill(req, file, fl, opcode, pid, flock); - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; /* locking is restartable */ if (err == -EINTR) @@ -1433,7 +1446,7 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block) req->out.numargs = 1; req->out.args[0].size = sizeof(outarg); req->out.args[0].value = &outarg; - request_send(fc, req); + fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); if (err == -ENOSYS) @@ -1470,6 +1483,406 @@ static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin) return retval; } +static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov, + unsigned int nr_segs, size_t bytes, bool to_user) +{ + struct iov_iter ii; + int page_idx = 0; + + if (!bytes) + return 0; + + iov_iter_init(&ii, iov, nr_segs, bytes, 0); + + while (iov_iter_count(&ii)) { + struct page *page = pages[page_idx++]; + size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii)); + void *kaddr, *map; + + kaddr = map = kmap(page); + + while (todo) { + char __user *uaddr = ii.iov->iov_base + ii.iov_offset; + size_t iov_len = ii.iov->iov_len - ii.iov_offset; + size_t copy = min(todo, iov_len); + size_t left; + + if (!to_user) + left = copy_from_user(kaddr, uaddr, copy); + else + left = copy_to_user(uaddr, kaddr, copy); + + if (unlikely(left)) + return -EFAULT; + + iov_iter_advance(&ii, copy); + todo -= copy; + kaddr += copy; + } + + kunmap(map); + } + + return 0; +} + +/* + * For ioctls, there is no generic way to determine how much memory + * needs to be read and/or written. Furthermore, ioctls are allowed + * to dereference the passed pointer, so the parameter requires deep + * copying but FUSE has no idea whatsoever about what to copy in or + * out. + * + * This is solved by allowing FUSE server to retry ioctl with + * necessary in/out iovecs. Let's assume the ioctl implementation + * needs to read in the following structure. + * + * struct a { + * char *buf; + * size_t buflen; + * } + * + * On the first callout to FUSE server, inarg->in_size and + * inarg->out_size will be NULL; then, the server completes the ioctl + * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and + * the actual iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } + * + * which tells FUSE to copy in the requested area and retry the ioctl. + * On the second round, the server has access to the structure and + * from that it can tell what to look for next, so on the invocation, + * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, + * { .iov_base = a.buf, .iov_len = a.buflen } } + * + * FUSE will copy both struct a and the pointed buffer from the + * process doing the ioctl and retry ioctl with both struct a and the + * buffer. + * + * This time, FUSE server has everything it needs and completes ioctl + * without FUSE_IOCTL_RETRY which finishes the ioctl call. + * + * Copying data out works the same way. + * + * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel + * automatically initializes in and out iovs by decoding @cmd with + * _IOC_* macros and the server is not allowed to request RETRY. This + * limits ioctl data transfers to well-formed ioctls and is the forced + * behavior for all FUSE servers. + */ +static long fuse_file_do_ioctl(struct file *file, unsigned int cmd, + unsigned long arg, unsigned int flags) +{ + struct inode *inode = file->f_dentry->d_inode; + struct fuse_file *ff = file->private_data; + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_ioctl_in inarg = { + .fh = ff->fh, + .cmd = cmd, + .arg = arg, + .flags = flags + }; + struct fuse_ioctl_out outarg; + struct fuse_req *req = NULL; + struct page **pages = NULL; + struct page *iov_page = NULL; + struct iovec *in_iov = NULL, *out_iov = NULL; + unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages; + size_t in_size, out_size, transferred; + int err; + + /* assume all the iovs returned by client always fits in a page */ + BUILD_BUG_ON(sizeof(struct iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); + + if (!fuse_allow_task(fc, current)) + return -EACCES; + + err = -EIO; + if (is_bad_inode(inode)) + goto out; + + err = -ENOMEM; + pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL); + iov_page = alloc_page(GFP_KERNEL); + if (!pages || !iov_page) + goto out; + + /* + * If restricted, initialize IO parameters as encoded in @cmd. + * RETRY from server is not allowed. + */ + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { + struct iovec *iov = page_address(iov_page); + + iov->iov_base = (void __user *)arg; + iov->iov_len = _IOC_SIZE(cmd); + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + in_iov = iov; + in_iovs = 1; + } + + if (_IOC_DIR(cmd) & _IOC_READ) { + out_iov = iov; + out_iovs = 1; + } + } + + retry: + inarg.in_size = in_size = iov_length(in_iov, in_iovs); + inarg.out_size = out_size = iov_length(out_iov, out_iovs); + + /* + * Out data can be used either for actual out data or iovs, + * make sure there always is at least one page. + */ + out_size = max_t(size_t, out_size, PAGE_SIZE); + max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); + + /* make sure there are enough buffer pages and init request with them */ + err = -ENOMEM; + if (max_pages > FUSE_MAX_PAGES_PER_REQ) + goto out; + while (num_pages < max_pages) { + pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (!pages[num_pages]) + goto out; + num_pages++; + } + + req = fuse_get_req(fc); + if (IS_ERR(req)) { + err = PTR_ERR(req); + req = NULL; + goto out; + } + memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages); + req->num_pages = num_pages; + + /* okay, let's send it to the client */ + req->in.h.opcode = FUSE_IOCTL; + req->in.h.nodeid = get_node_id(inode); + req->in.numargs = 1; + req->in.args[0].size = sizeof(inarg); + req->in.args[0].value = &inarg; + if (in_size) { + req->in.numargs++; + req->in.args[1].size = in_size; + req->in.argpages = 1; + + err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size, + false); + if (err) + goto out; + } + + req->out.numargs = 2; + req->out.args[0].size = sizeof(outarg); + req->out.args[0].value = &outarg; + req->out.args[1].size = out_size; + req->out.argpages = 1; + req->out.argvar = 1; + + fuse_request_send(fc, req); + err = req->out.h.error; + transferred = req->out.args[1].size; + fuse_put_request(fc, req); + req = NULL; + if (err) + goto out; + + /* did it ask for retry? */ + if (outarg.flags & FUSE_IOCTL_RETRY) { + char *vaddr; + + /* no retry if in restricted mode */ + err = -EIO; + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) + goto out; + + in_iovs = outarg.in_iovs; + out_iovs = outarg.out_iovs; + + /* + * Make sure things are in boundary, separate checks + * are to protect against overflow. + */ + err = -ENOMEM; + if (in_iovs > FUSE_IOCTL_MAX_IOV || + out_iovs > FUSE_IOCTL_MAX_IOV || + in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) + goto out; + + err = -EIO; + if ((in_iovs + out_iovs) * sizeof(struct iovec) != transferred) + goto out; + + /* okay, copy in iovs and retry */ + vaddr = kmap_atomic(pages[0], KM_USER0); + memcpy(page_address(iov_page), vaddr, transferred); + kunmap_atomic(vaddr, KM_USER0); + + in_iov = page_address(iov_page); + out_iov = in_iov + in_iovs; + + goto retry; + } + + err = -EIO; + if (transferred > inarg.out_size) + goto out; + + err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true); + out: + if (req) + fuse_put_request(fc, req); + if (iov_page) + __free_page(iov_page); + while (num_pages) + __free_page(pages[--num_pages]); + kfree(pages); + + return err ? err : outarg.result; +} + +static long fuse_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return fuse_file_do_ioctl(file, cmd, arg, 0); +} + +static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return fuse_file_do_ioctl(file, cmd, arg, FUSE_IOCTL_COMPAT); +} + +/* + * All files which have been polled are linked to RB tree + * fuse_conn->polled_files which is indexed by kh. Walk the tree and + * find the matching one. + */ +static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh, + struct rb_node **parent_out) +{ + struct rb_node **link = &fc->polled_files.rb_node; + struct rb_node *last = NULL; + + while (*link) { + struct fuse_file *ff; + + last = *link; + ff = rb_entry(last, struct fuse_file, polled_node); + + if (kh < ff->kh) + link = &last->rb_left; + else if (kh > ff->kh) + link = &last->rb_right; + else + return link; + } + + if (parent_out) + *parent_out = last; + return link; +} + +/* + * The file is about to be polled. Make sure it's on the polled_files + * RB tree. Note that files once added to the polled_files tree are + * not removed before the file is released. This is because a file + * polled once is likely to be polled again. + */ +static void fuse_register_polled_file(struct fuse_conn *fc, + struct fuse_file *ff) +{ + spin_lock(&fc->lock); + if (RB_EMPTY_NODE(&ff->polled_node)) { + struct rb_node **link, *parent; + + link = fuse_find_polled_node(fc, ff->kh, &parent); + BUG_ON(*link); + rb_link_node(&ff->polled_node, parent, link); + rb_insert_color(&ff->polled_node, &fc->polled_files); + } + spin_unlock(&fc->lock); +} + +static unsigned fuse_file_poll(struct file *file, poll_table *wait) +{ + struct inode *inode = file->f_dentry->d_inode; + struct fuse_file *ff = file->private_data; + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh }; + struct fuse_poll_out outarg; + struct fuse_req *req; + int err; + + if (fc->no_poll) + return DEFAULT_POLLMASK; + + poll_wait(file, &ff->poll_wait, wait); + + /* + * Ask for notification iff there's someone waiting for it. + * The client may ignore the flag and always notify. + */ + if (waitqueue_active(&ff->poll_wait)) { + inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY; + fuse_register_polled_file(fc, ff); + } + + req = fuse_get_req(fc); + if (IS_ERR(req)) + return PTR_ERR(req); + + req->in.h.opcode = FUSE_POLL; + req->in.h.nodeid = get_node_id(inode); + req->in.numargs = 1; + req->in.args[0].size = sizeof(inarg); + req->in.args[0].value = &inarg; + req->out.numargs = 1; + req->out.args[0].size = sizeof(outarg); + req->out.args[0].value = &outarg; + fuse_request_send(fc, req); + err = req->out.h.error; + fuse_put_request(fc, req); + + if (!err) + return outarg.revents; + if (err == -ENOSYS) { + fc->no_poll = 1; + return DEFAULT_POLLMASK; + } + return POLLERR; +} + +/* + * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and + * wakes up the poll waiters. + */ +int fuse_notify_poll_wakeup(struct fuse_conn *fc, + struct fuse_notify_poll_wakeup_out *outarg) +{ + u64 kh = outarg->kh; + struct rb_node **link; + + spin_lock(&fc->lock); + + link = fuse_find_polled_node(fc, kh, NULL); + if (*link) { + struct fuse_file *ff; + + ff = rb_entry(*link, struct fuse_file, polled_node); + wake_up_interruptible_sync(&ff->poll_wait); + } + + spin_unlock(&fc->lock); + return 0; +} + static const struct file_operations fuse_file_operations = { .llseek = fuse_file_llseek, .read = do_sync_read, @@ -1484,6 +1897,9 @@ static const struct file_operations fuse_file_operations = { .lock = fuse_file_lock, .flock = fuse_file_flock, .splice_read = generic_file_splice_read, + .unlocked_ioctl = fuse_file_ioctl, + .compat_ioctl = fuse_file_compat_ioctl, + .poll = fuse_file_poll, }; static const struct file_operations fuse_direct_io_file_operations = { @@ -1496,6 +1912,9 @@ static const struct file_operations fuse_direct_io_file_operations = { .fsync = fuse_fsync, .lock = fuse_file_lock, .flock = fuse_file_flock, + .unlocked_ioctl = fuse_file_ioctl, + .compat_ioctl = fuse_file_compat_ioctl, + .poll = fuse_file_poll, /* no mmap and splice_read */ }; |