| /* |
| FUSE: Filesystem in Userspace |
| 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. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/pagemap.h> |
| #include <linux/slab.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/module.h> |
| #include <linux/compat.h> |
| #include <linux/swap.h> |
| #include <linux/aio.h> |
| #include <linux/falloc.h> |
| |
| static const struct file_operations fuse_direct_io_file_operations; |
| |
| static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file, |
| int opcode, struct fuse_open_out *outargp) |
| { |
| struct fuse_open_in inarg; |
| struct fuse_req *req; |
| int err; |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); |
| if (!fc->atomic_o_trunc) |
| inarg.flags &= ~O_TRUNC; |
| req->in.h.opcode = opcode; |
| req->in.h.nodeid = nodeid; |
| 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(*outargp); |
| req->out.args[0].value = outargp; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| |
| return err; |
| } |
| |
| struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) |
| { |
| struct fuse_file *ff; |
| |
| ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); |
| if (unlikely(!ff)) |
| return NULL; |
| |
| ff->fc = fc; |
| ff->reserved_req = fuse_request_alloc(0); |
| if (unlikely(!ff->reserved_req)) { |
| kfree(ff); |
| return NULL; |
| } |
| |
| INIT_LIST_HEAD(&ff->write_entry); |
| atomic_set(&ff->count, 0); |
| RB_CLEAR_NODE(&ff->polled_node); |
| init_waitqueue_head(&ff->poll_wait); |
| |
| spin_lock(&fc->lock); |
| ff->kh = ++fc->khctr; |
| spin_unlock(&fc->lock); |
| |
| return ff; |
| } |
| |
| void fuse_file_free(struct fuse_file *ff) |
| { |
| fuse_request_free(ff->reserved_req); |
| kfree(ff); |
| } |
| |
| struct fuse_file *fuse_file_get(struct fuse_file *ff) |
| { |
| atomic_inc(&ff->count); |
| return ff; |
| } |
| |
| static void fuse_release_async(struct work_struct *work) |
| { |
| struct fuse_req *req; |
| struct fuse_conn *fc; |
| struct path path; |
| |
| req = container_of(work, struct fuse_req, misc.release.work); |
| path = req->misc.release.path; |
| fc = get_fuse_conn(path.dentry->d_inode); |
| |
| fuse_put_request(fc, req); |
| path_put(&path); |
| } |
| |
| static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| if (fc->destroy_req) { |
| /* |
| * If this is a fuseblk mount, then it's possible that |
| * releasing the path will result in releasing the |
| * super block and sending the DESTROY request. If |
| * the server is single threaded, this would hang. |
| * For this reason do the path_put() in a separate |
| * thread. |
| */ |
| atomic_inc(&req->count); |
| INIT_WORK(&req->misc.release.work, fuse_release_async); |
| schedule_work(&req->misc.release.work); |
| } else { |
| path_put(&req->misc.release.path); |
| } |
| } |
| |
| static void fuse_file_put(struct fuse_file *ff, bool sync) |
| { |
| if (atomic_dec_and_test(&ff->count)) { |
| struct fuse_req *req = ff->reserved_req; |
| |
| if (sync) { |
| req->background = 0; |
| fuse_request_send(ff->fc, req); |
| path_put(&req->misc.release.path); |
| fuse_put_request(ff->fc, req); |
| } else { |
| req->end = fuse_release_end; |
| req->background = 1; |
| fuse_request_send_background(ff->fc, req); |
| } |
| kfree(ff); |
| } |
| } |
| |
| int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, |
| bool isdir) |
| { |
| struct fuse_open_out outarg; |
| struct fuse_file *ff; |
| int err; |
| int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; |
| |
| ff = fuse_file_alloc(fc); |
| if (!ff) |
| return -ENOMEM; |
| |
| err = fuse_send_open(fc, nodeid, file, opcode, &outarg); |
| if (err) { |
| fuse_file_free(ff); |
| return err; |
| } |
| |
| if (isdir) |
| outarg.open_flags &= ~FOPEN_DIRECT_IO; |
| |
| ff->fh = outarg.fh; |
| ff->nodeid = nodeid; |
| ff->open_flags = outarg.open_flags; |
| file->private_data = fuse_file_get(ff); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(fuse_do_open); |
| |
| void fuse_finish_open(struct inode *inode, struct file *file) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (ff->open_flags & FOPEN_DIRECT_IO) |
| file->f_op = &fuse_direct_io_file_operations; |
| if (!(ff->open_flags & FOPEN_KEEP_CACHE)) |
| invalidate_inode_pages2(inode->i_mapping); |
| if (ff->open_flags & FOPEN_NONSEEKABLE) |
| nonseekable_open(inode, file); |
| if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| fi->attr_version = ++fc->attr_version; |
| i_size_write(inode, 0); |
| spin_unlock(&fc->lock); |
| fuse_invalidate_attr(inode); |
| } |
| } |
| |
| int fuse_open_common(struct inode *inode, struct file *file, bool isdir) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| int err; |
| |
| err = generic_file_open(inode, file); |
| if (err) |
| return err; |
| |
| err = fuse_do_open(fc, get_node_id(inode), file, isdir); |
| if (err) |
| return err; |
| |
| fuse_finish_open(inode, file); |
| |
| return 0; |
| } |
| |
| static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode) |
| { |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_req *req = ff->reserved_req; |
| struct fuse_release_in *inarg = &req->misc.release.in; |
| |
| 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_all(&ff->poll_wait); |
| |
| inarg->fh = ff->fh; |
| inarg->flags = flags; |
| req->in.h.opcode = opcode; |
| req->in.h.nodeid = ff->nodeid; |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(struct fuse_release_in); |
| req->in.args[0].value = inarg; |
| } |
| |
| void fuse_release_common(struct file *file, int opcode) |
| { |
| struct fuse_file *ff; |
| struct fuse_req *req; |
| |
| ff = file->private_data; |
| if (unlikely(!ff)) |
| return; |
| |
| req = ff->reserved_req; |
| fuse_prepare_release(ff, file->f_flags, opcode); |
| |
| if (ff->flock) { |
| struct fuse_release_in *inarg = &req->misc.release.in; |
| inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; |
| inarg->lock_owner = fuse_lock_owner_id(ff->fc, |
| (fl_owner_t) file); |
| } |
| /* Hold vfsmount and dentry until release is finished */ |
| path_get(&file->f_path); |
| req->misc.release.path = file->f_path; |
| |
| /* |
| * Normally this will send the RELEASE request, however if |
| * some asynchronous READ or WRITE requests are outstanding, |
| * the sending will be delayed. |
| * |
| * Make the release synchronous if this is a fuseblk mount, |
| * synchronous RELEASE is allowed (and desirable) in this case |
| * because the server can be trusted not to screw up. |
| */ |
| fuse_file_put(ff, ff->fc->destroy_req != NULL); |
| } |
| |
| static int fuse_open(struct inode *inode, struct file *file) |
| { |
| return fuse_open_common(inode, file, false); |
| } |
| |
| static int fuse_release(struct inode *inode, struct file *file) |
| { |
| fuse_release_common(file, FUSE_RELEASE); |
| |
| /* return value is ignored by VFS */ |
| return 0; |
| } |
| |
| void fuse_sync_release(struct fuse_file *ff, int flags) |
| { |
| WARN_ON(atomic_read(&ff->count) > 1); |
| fuse_prepare_release(ff, flags, FUSE_RELEASE); |
| ff->reserved_req->force = 1; |
| ff->reserved_req->background = 0; |
| fuse_request_send(ff->fc, ff->reserved_req); |
| fuse_put_request(ff->fc, ff->reserved_req); |
| kfree(ff); |
| } |
| EXPORT_SYMBOL_GPL(fuse_sync_release); |
| |
| /* |
| * Scramble the ID space with XTEA, so that the value of the files_struct |
| * pointer is not exposed to userspace. |
| */ |
| u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id) |
| { |
| u32 *k = fc->scramble_key; |
| u64 v = (unsigned long) id; |
| u32 v0 = v; |
| u32 v1 = v >> 32; |
| u32 sum = 0; |
| int i; |
| |
| for (i = 0; i < 32; i++) { |
| v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]); |
| sum += 0x9E3779B9; |
| v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]); |
| } |
| |
| return (u64) v0 + ((u64) v1 << 32); |
| } |
| |
| /* |
| * Check if page is under writeback |
| * |
| * This is currently done by walking the list of writepage requests |
| * for the inode, which can be pretty inefficient. |
| */ |
| static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_req *req; |
| bool found = false; |
| |
| spin_lock(&fc->lock); |
| list_for_each_entry(req, &fi->writepages, writepages_entry) { |
| pgoff_t curr_index; |
| |
| BUG_ON(req->inode != inode); |
| curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT; |
| if (curr_index <= index && |
| index < curr_index + req->num_pages) { |
| found = true; |
| break; |
| } |
| } |
| spin_unlock(&fc->lock); |
| |
| return found; |
| } |
| |
| /* |
| * Wait for page writeback to be completed. |
| * |
| * Since fuse doesn't rely on the VM writeback tracking, this has to |
| * use some other means. |
| */ |
| static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index)); |
| return 0; |
| } |
| |
| static int fuse_flush(struct file *file, fl_owner_t id) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| struct fuse_req *req; |
| struct fuse_flush_in inarg; |
| int err; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| if (fc->no_flush) |
| return 0; |
| |
| req = fuse_get_req_nofail_nopages(fc, file); |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.fh = ff->fh; |
| inarg.lock_owner = fuse_lock_owner_id(fc, id); |
| req->in.h.opcode = FUSE_FLUSH; |
| 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->force = 1; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| fc->no_flush = 1; |
| err = 0; |
| } |
| return err; |
| } |
| |
| /* |
| * Wait for all pending writepages on the inode to finish. |
| * |
| * This is currently done by blocking further writes with FUSE_NOWRITE |
| * and waiting for all sent writes to complete. |
| * |
| * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage |
| * could conflict with truncation. |
| */ |
| static void fuse_sync_writes(struct inode *inode) |
| { |
| fuse_set_nowrite(inode); |
| fuse_release_nowrite(inode); |
| } |
| |
| int fuse_fsync_common(struct file *file, loff_t start, loff_t end, |
| int datasync, int isdir) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| struct fuse_req *req; |
| struct fuse_fsync_in inarg; |
| int err; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| if (err) |
| return err; |
| |
| if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir)) |
| return 0; |
| |
| mutex_lock(&inode->i_mutex); |
| |
| /* |
| * Start writeback against all dirty pages of the inode, then |
| * wait for all outstanding writes, before sending the FSYNC |
| * request. |
| */ |
| err = write_inode_now(inode, 0); |
| if (err) |
| goto out; |
| |
| fuse_sync_writes(inode); |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) { |
| err = PTR_ERR(req); |
| goto out; |
| } |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.fh = ff->fh; |
| inarg.fsync_flags = datasync ? 1 : 0; |
| req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC; |
| 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; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| if (isdir) |
| fc->no_fsyncdir = 1; |
| else |
| fc->no_fsync = 1; |
| err = 0; |
| } |
| out: |
| mutex_unlock(&inode->i_mutex); |
| return err; |
| } |
| |
| static int fuse_fsync(struct file *file, loff_t start, loff_t end, |
| int datasync) |
| { |
| return fuse_fsync_common(file, start, end, datasync, 0); |
| } |
| |
| void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos, |
| size_t count, int opcode) |
| { |
| struct fuse_read_in *inarg = &req->misc.read.in; |
| struct fuse_file *ff = file->private_data; |
| |
| inarg->fh = ff->fh; |
| inarg->offset = pos; |
| inarg->size = count; |
| inarg->flags = file->f_flags; |
| req->in.h.opcode = opcode; |
| req->in.h.nodeid = ff->nodeid; |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(struct fuse_read_in); |
| req->in.args[0].value = inarg; |
| req->out.argvar = 1; |
| req->out.numargs = 1; |
| req->out.args[0].size = count; |
| } |
| |
| static void fuse_release_user_pages(struct fuse_req *req, int write) |
| { |
| unsigned i; |
| |
| for (i = 0; i < req->num_pages; i++) { |
| struct page *page = req->pages[i]; |
| if (write) |
| set_page_dirty_lock(page); |
| put_page(page); |
| } |
| } |
| |
| /** |
| * In case of short read, the caller sets 'pos' to the position of |
| * actual end of fuse request in IO request. Otherwise, if bytes_requested |
| * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1. |
| * |
| * An example: |
| * User requested DIO read of 64K. It was splitted into two 32K fuse requests, |
| * both submitted asynchronously. The first of them was ACKed by userspace as |
| * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The |
| * second request was ACKed as short, e.g. only 1K was read, resulting in |
| * pos == 33K. |
| * |
| * Thus, when all fuse requests are completed, the minimal non-negative 'pos' |
| * will be equal to the length of the longest contiguous fragment of |
| * transferred data starting from the beginning of IO request. |
| */ |
| static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos) |
| { |
| int left; |
| |
| spin_lock(&io->lock); |
| if (err) |
| io->err = io->err ? : err; |
| else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes)) |
| io->bytes = pos; |
| |
| left = --io->reqs; |
| spin_unlock(&io->lock); |
| |
| if (!left) { |
| long res; |
| |
| if (io->err) |
| res = io->err; |
| else if (io->bytes >= 0 && io->write) |
| res = -EIO; |
| else { |
| res = io->bytes < 0 ? io->size : io->bytes; |
| |
| if (!is_sync_kiocb(io->iocb)) { |
| struct inode *inode = file_inode(io->iocb->ki_filp); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| fi->attr_version = ++fc->attr_version; |
| spin_unlock(&fc->lock); |
| } |
| } |
| |
| aio_complete(io->iocb, res, 0); |
| kfree(io); |
| } |
| } |
| |
| static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| struct fuse_io_priv *io = req->io; |
| ssize_t pos = -1; |
| |
| fuse_release_user_pages(req, !io->write); |
| |
| if (io->write) { |
| if (req->misc.write.in.size != req->misc.write.out.size) |
| pos = req->misc.write.in.offset - io->offset + |
| req->misc.write.out.size; |
| } else { |
| if (req->misc.read.in.size != req->out.args[0].size) |
| pos = req->misc.read.in.offset - io->offset + |
| req->out.args[0].size; |
| } |
| |
| fuse_aio_complete(io, req->out.h.error, pos); |
| } |
| |
| static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req, |
| size_t num_bytes, struct fuse_io_priv *io) |
| { |
| spin_lock(&io->lock); |
| io->size += num_bytes; |
| io->reqs++; |
| spin_unlock(&io->lock); |
| |
| req->io = io; |
| req->end = fuse_aio_complete_req; |
| |
| __fuse_get_request(req); |
| fuse_request_send_background(fc, req); |
| |
| return num_bytes; |
| } |
| |
| static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io, |
| loff_t pos, size_t count, fl_owner_t owner) |
| { |
| struct file *file = io->file; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| |
| fuse_read_fill(req, file, pos, count, FUSE_READ); |
| if (owner != NULL) { |
| struct fuse_read_in *inarg = &req->misc.read.in; |
| |
| inarg->read_flags |= FUSE_READ_LOCKOWNER; |
| inarg->lock_owner = fuse_lock_owner_id(fc, owner); |
| } |
| |
| if (io->async) |
| return fuse_async_req_send(fc, req, count, io); |
| |
| fuse_request_send(fc, req); |
| return req->out.args[0].size; |
| } |
| |
| static void fuse_read_update_size(struct inode *inode, loff_t size, |
| u64 attr_ver) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| if (attr_ver == fi->attr_version && size < inode->i_size && |
| !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { |
| fi->attr_version = ++fc->attr_version; |
| i_size_write(inode, size); |
| } |
| spin_unlock(&fc->lock); |
| } |
| |
| static int fuse_readpage(struct file *file, struct page *page) |
| { |
| struct fuse_io_priv io = { .async = 0, .file = file }; |
| struct inode *inode = page->mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| size_t num_read; |
| loff_t pos = page_offset(page); |
| size_t count = PAGE_CACHE_SIZE; |
| u64 attr_ver; |
| int err; |
| |
| err = -EIO; |
| if (is_bad_inode(inode)) |
| goto out; |
| |
| /* |
| * Page writeback can extend beyond the lifetime of the |
| * page-cache page, so make sure we read a properly synced |
| * page. |
| */ |
| fuse_wait_on_page_writeback(inode, page->index); |
| |
| req = fuse_get_req(fc, 1); |
| err = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out; |
| |
| attr_ver = fuse_get_attr_version(fc); |
| |
| req->out.page_zeroing = 1; |
| req->out.argpages = 1; |
| req->num_pages = 1; |
| req->pages[0] = page; |
| req->page_descs[0].length = count; |
| num_read = fuse_send_read(req, &io, pos, count, NULL); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| |
| if (!err) { |
| /* |
| * Short read means EOF. If file size is larger, truncate it |
| */ |
| if (num_read < count) |
| fuse_read_update_size(inode, pos + num_read, attr_ver); |
| |
| SetPageUptodate(page); |
| } |
| |
| fuse_invalidate_attr(inode); /* atime changed */ |
| out: |
| unlock_page(page); |
| return err; |
| } |
| |
| static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| int i; |
| size_t count = req->misc.read.in.size; |
| size_t num_read = req->out.args[0].size; |
| struct address_space *mapping = NULL; |
| |
| for (i = 0; mapping == NULL && i < req->num_pages; i++) |
| mapping = req->pages[i]->mapping; |
| |
| if (mapping) { |
| struct inode *inode = mapping->host; |
| |
| /* |
| * Short read means EOF. If file size is larger, truncate it |
| */ |
| if (!req->out.h.error && num_read < count) { |
| loff_t pos; |
| |
| pos = page_offset(req->pages[0]) + num_read; |
| fuse_read_update_size(inode, pos, |
| req->misc.read.attr_ver); |
| } |
| fuse_invalidate_attr(inode); /* atime changed */ |
| } |
| |
| for (i = 0; i < req->num_pages; i++) { |
| struct page *page = req->pages[i]; |
| if (!req->out.h.error) |
| SetPageUptodate(page); |
| else |
| SetPageError(page); |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| if (req->ff) |
| fuse_file_put(req->ff, false); |
| } |
| |
| static void fuse_send_readpages(struct fuse_req *req, struct file *file) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| loff_t pos = page_offset(req->pages[0]); |
| size_t count = req->num_pages << PAGE_CACHE_SHIFT; |
| |
| req->out.argpages = 1; |
| req->out.page_zeroing = 1; |
| req->out.page_replace = 1; |
| fuse_read_fill(req, file, pos, count, FUSE_READ); |
| req->misc.read.attr_ver = fuse_get_attr_version(fc); |
| if (fc->async_read) { |
| req->ff = fuse_file_get(ff); |
| req->end = fuse_readpages_end; |
| fuse_request_send_background(fc, req); |
| } else { |
| fuse_request_send(fc, req); |
| fuse_readpages_end(fc, req); |
| fuse_put_request(fc, req); |
| } |
| } |
| |
| struct fuse_fill_data { |
| struct fuse_req *req; |
| struct file *file; |
| struct inode *inode; |
| unsigned nr_pages; |
| }; |
| |
| static int fuse_readpages_fill(void *_data, struct page *page) |
| { |
| struct fuse_fill_data *data = _data; |
| struct fuse_req *req = data->req; |
| struct inode *inode = data->inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| fuse_wait_on_page_writeback(inode, page->index); |
| |
| if (req->num_pages && |
| (req->num_pages == FUSE_MAX_PAGES_PER_REQ || |
| (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read || |
| req->pages[req->num_pages - 1]->index + 1 != page->index)) { |
| int nr_alloc = min_t(unsigned, data->nr_pages, |
| FUSE_MAX_PAGES_PER_REQ); |
| fuse_send_readpages(req, data->file); |
| if (fc->async_read) |
| req = fuse_get_req_for_background(fc, nr_alloc); |
| else |
| req = fuse_get_req(fc, nr_alloc); |
| |
| data->req = req; |
| if (IS_ERR(req)) { |
| unlock_page(page); |
| return PTR_ERR(req); |
| } |
| } |
| |
| if (WARN_ON(req->num_pages >= req->max_pages)) { |
| fuse_put_request(fc, req); |
| return -EIO; |
| } |
| |
| page_cache_get(page); |
| req->pages[req->num_pages] = page; |
| req->page_descs[req->num_pages].length = PAGE_SIZE; |
| req->num_pages++; |
| data->nr_pages--; |
| return 0; |
| } |
| |
| static int fuse_readpages(struct file *file, struct address_space *mapping, |
| struct list_head *pages, unsigned nr_pages) |
| { |
| struct inode *inode = mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_fill_data data; |
| int err; |
| int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ); |
| |
| err = -EIO; |
| if (is_bad_inode(inode)) |
| goto out; |
| |
| data.file = file; |
| data.inode = inode; |
| if (fc->async_read) |
| data.req = fuse_get_req_for_background(fc, nr_alloc); |
| else |
| data.req = fuse_get_req(fc, nr_alloc); |
| data.nr_pages = nr_pages; |
| err = PTR_ERR(data.req); |
| if (IS_ERR(data.req)) |
| goto out; |
| |
| err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data); |
| if (!err) { |
| if (data.req->num_pages) |
| fuse_send_readpages(data.req, file); |
| else |
| fuse_put_request(fc, data.req); |
| } |
| out: |
| return err; |
| } |
| |
| static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct inode *inode = iocb->ki_filp->f_mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| /* |
| * In auto invalidate mode, always update attributes on read. |
| * Otherwise, only update if we attempt to read past EOF (to ensure |
| * i_size is up to date). |
| */ |
| if (fc->auto_inval_data || |
| (pos + iov_length(iov, nr_segs) > i_size_read(inode))) { |
| int err; |
| err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL); |
| if (err) |
| return err; |
| } |
| |
| return generic_file_aio_read(iocb, iov, nr_segs, pos); |
| } |
| |
| static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff, |
| loff_t pos, size_t count) |
| { |
| struct fuse_write_in *inarg = &req->misc.write.in; |
| struct fuse_write_out *outarg = &req->misc.write.out; |
| |
| inarg->fh = ff->fh; |
| inarg->offset = pos; |
| inarg->size = count; |
| req->in.h.opcode = FUSE_WRITE; |
| req->in.h.nodeid = ff->nodeid; |
| req->in.numargs = 2; |
| if (ff->fc->minor < 9) |
| req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE; |
| else |
| req->in.args[0].size = sizeof(struct fuse_write_in); |
| req->in.args[0].value = inarg; |
| req->in.args[1].size = count; |
| req->out.numargs = 1; |
| req->out.args[0].size = sizeof(struct fuse_write_out); |
| req->out.args[0].value = outarg; |
| } |
| |
| static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io, |
| loff_t pos, size_t count, fl_owner_t owner) |
| { |
| struct file *file = io->file; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_write_in *inarg = &req->misc.write.in; |
| |
| fuse_write_fill(req, ff, pos, count); |
| inarg->flags = file->f_flags; |
| if (owner != NULL) { |
| inarg->write_flags |= FUSE_WRITE_LOCKOWNER; |
| inarg->lock_owner = fuse_lock_owner_id(fc, owner); |
| } |
| |
| if (io->async) |
| return fuse_async_req_send(fc, req, count, io); |
| |
| fuse_request_send(fc, req); |
| return req->misc.write.out.size; |
| } |
| |
| void fuse_write_update_size(struct inode *inode, loff_t pos) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| fi->attr_version = ++fc->attr_version; |
| if (pos > inode->i_size) |
| i_size_write(inode, pos); |
| spin_unlock(&fc->lock); |
| } |
| |
| static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, |
| struct inode *inode, loff_t pos, |
| size_t count) |
| { |
| size_t res; |
| unsigned offset; |
| unsigned i; |
| struct fuse_io_priv io = { .async = 0, .file = file }; |
| |
| for (i = 0; i < req->num_pages; i++) |
| fuse_wait_on_page_writeback(inode, req->pages[i]->index); |
| |
| res = fuse_send_write(req, &io, pos, count, NULL); |
| |
| offset = req->page_descs[0].offset; |
| count = res; |
| for (i = 0; i < req->num_pages; i++) { |
| struct page *page = req->pages[i]; |
| |
| if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE) |
| SetPageUptodate(page); |
| |
| if (count > PAGE_CACHE_SIZE - offset) |
| count -= PAGE_CACHE_SIZE - offset; |
| else |
| count = 0; |
| offset = 0; |
| |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| |
| return res; |
| } |
| |
| static ssize_t fuse_fill_write_pages(struct fuse_req *req, |
| struct address_space *mapping, |
| struct iov_iter *ii, loff_t pos) |
| { |
| struct fuse_conn *fc = get_fuse_conn(mapping->host); |
| unsigned offset = pos & (PAGE_CACHE_SIZE - 1); |
| size_t count = 0; |
| int err; |
| |
| req->in.argpages = 1; |
| req->page_descs[0].offset = offset; |
| |
| do { |
| size_t tmp; |
| struct page *page; |
| pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset, |
| iov_iter_count(ii)); |
| |
| bytes = min_t(size_t, bytes, fc->max_write - count); |
| |
| again: |
| err = -EFAULT; |
| if (iov_iter_fault_in_readable(ii, bytes)) |
| break; |
| |
| err = -ENOMEM; |
| page = grab_cache_page_write_begin(mapping, index, 0); |
| if (!page) |
| break; |
| |
| if (mapping_writably_mapped(mapping)) |
| flush_dcache_page(page); |
| |
| pagefault_disable(); |
| tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); |
| pagefault_enable(); |
| flush_dcache_page(page); |
| |
| mark_page_accessed(page); |
| |
| if (!tmp) { |
| unlock_page(page); |
| page_cache_release(page); |
| bytes = min(bytes, iov_iter_single_seg_count(ii)); |
| goto again; |
| } |
| |
| err = 0; |
| req->pages[req->num_pages] = page; |
| req->page_descs[req->num_pages].length = tmp; |
| req->num_pages++; |
| |
| iov_iter_advance(ii, tmp); |
| count += tmp; |
| pos += tmp; |
| offset += tmp; |
| if (offset == PAGE_CACHE_SIZE) |
| offset = 0; |
| |
| if (!fc->big_writes) |
| break; |
| } while (iov_iter_count(ii) && count < fc->max_write && |
| req->num_pages < req->max_pages && offset == 0); |
| |
| return count > 0 ? count : err; |
| } |
| |
| static inline unsigned fuse_wr_pages(loff_t pos, size_t len) |
| { |
| return min_t(unsigned, |
| ((pos + len - 1) >> PAGE_CACHE_SHIFT) - |
| (pos >> PAGE_CACHE_SHIFT) + 1, |
| FUSE_MAX_PAGES_PER_REQ); |
| } |
| |
| static ssize_t fuse_perform_write(struct file *file, |
| struct address_space *mapping, |
| struct iov_iter *ii, loff_t pos) |
| { |
| struct inode *inode = mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| int err = 0; |
| ssize_t res = 0; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| if (inode->i_size < pos + iov_iter_count(ii)) |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| |
| do { |
| struct fuse_req *req; |
| ssize_t count; |
| unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii)); |
| |
| req = fuse_get_req(fc, nr_pages); |
| if (IS_ERR(req)) { |
| err = PTR_ERR(req); |
| break; |
| } |
| |
| count = fuse_fill_write_pages(req, mapping, ii, pos); |
| if (count <= 0) { |
| err = count; |
| } else { |
| size_t num_written; |
| |
| num_written = fuse_send_write_pages(req, file, inode, |
| pos, count); |
| err = req->out.h.error; |
| if (!err) { |
| res += num_written; |
| pos += num_written; |
| |
| /* break out of the loop on short write */ |
| if (num_written != count) |
| err = -EIO; |
| } |
| } |
| fuse_put_request(fc, req); |
| } while (!err && iov_iter_count(ii)); |
| |
| if (res > 0) |
| fuse_write_update_size(inode, pos); |
| |
| clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| fuse_invalidate_attr(inode); |
| |
| return res > 0 ? res : err; |
| } |
| |
| static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct file *file = iocb->ki_filp; |
| struct address_space *mapping = file->f_mapping; |
| size_t count = 0; |
| size_t ocount = 0; |
| ssize_t written = 0; |
| ssize_t written_buffered = 0; |
| struct inode *inode = mapping->host; |
| ssize_t err; |
| struct iov_iter i; |
| loff_t endbyte = 0; |
| |
| WARN_ON(iocb->ki_pos != pos); |
| |
| ocount = 0; |
| err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); |
| if (err) |
| return err; |
| |
| count = ocount; |
| mutex_lock(&inode->i_mutex); |
| |
| /* We can write back this queue in page reclaim */ |
| current->backing_dev_info = mapping->backing_dev_info; |
| |
| err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| if (err) |
| goto out; |
| |
| if (count == 0) |
| goto out; |
| |
| err = file_remove_suid(file); |
| if (err) |
| goto out; |
| |
| err = file_update_time(file); |
| if (err) |
| goto out; |
| |
| if (file->f_flags & O_DIRECT) { |
| written = generic_file_direct_write(iocb, iov, &nr_segs, |
| pos, &iocb->ki_pos, |
| count, ocount); |
| if (written < 0 || written == count) |
| goto out; |
| |
| pos += written; |
| count -= written; |
| |
| iov_iter_init(&i, iov, nr_segs, count, written); |
| written_buffered = fuse_perform_write(file, mapping, &i, pos); |
| if (written_buffered < 0) { |
| err = written_buffered; |
| goto out; |
| } |
| endbyte = pos + written_buffered - 1; |
| |
| err = filemap_write_and_wait_range(file->f_mapping, pos, |
| endbyte); |
| if (err) |
| goto out; |
| |
| invalidate_mapping_pages(file->f_mapping, |
| pos >> PAGE_CACHE_SHIFT, |
| endbyte >> PAGE_CACHE_SHIFT); |
| |
| written += written_buffered; |
| iocb->ki_pos = pos + written_buffered; |
| } else { |
| iov_iter_init(&i, iov, nr_segs, count, 0); |
| written = fuse_perform_write(file, mapping, &i, pos); |
| if (written >= 0) |
| iocb->ki_pos = pos + written; |
| } |
| out: |
| current->backing_dev_info = NULL; |
| mutex_unlock(&inode->i_mutex); |
| |
| return written ? written : err; |
| } |
| |
| static inline void fuse_page_descs_length_init(struct fuse_req *req, |
| unsigned index, unsigned nr_pages) |
| { |
| int i; |
| |
| for (i = index; i < index + nr_pages; i++) |
| req->page_descs[i].length = PAGE_SIZE - |
| req->page_descs[i].offset; |
| } |
| |
| static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii) |
| { |
| return (unsigned long)ii->iov->iov_base + ii->iov_offset; |
| } |
| |
| static inline size_t fuse_get_frag_size(const struct iov_iter *ii, |
| size_t max_size) |
| { |
| return min(iov_iter_single_seg_count(ii), max_size); |
| } |
| |
| static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, |
| size_t *nbytesp, int write) |
| { |
| size_t nbytes = 0; /* # bytes already packed in req */ |
| |
| /* Special case for kernel I/O: can copy directly into the buffer */ |
| if (segment_eq(get_fs(), KERNEL_DS)) { |
| unsigned long user_addr = fuse_get_user_addr(ii); |
| size_t frag_size = fuse_get_frag_size(ii, *nbytesp); |
| |
| if (write) |
| req->in.args[1].value = (void *) user_addr; |
| else |
| req->out.args[0].value = (void *) user_addr; |
| |
| iov_iter_advance(ii, frag_size); |
| *nbytesp = frag_size; |
| return 0; |
| } |
| |
| while (nbytes < *nbytesp && req->num_pages < req->max_pages) { |
| unsigned npages; |
| unsigned long user_addr = fuse_get_user_addr(ii); |
| unsigned offset = user_addr & ~PAGE_MASK; |
| size_t frag_size = fuse_get_frag_size(ii, *nbytesp - nbytes); |
| int ret; |
| |
| unsigned n = req->max_pages - req->num_pages; |
| frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT); |
| |
| npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| npages = clamp(npages, 1U, n); |
| |
| ret = get_user_pages_fast(user_addr, npages, !write, |
| &req->pages[req->num_pages]); |
| if (ret < 0) |
| return ret; |
| |
| npages = ret; |
| frag_size = min_t(size_t, frag_size, |
| (npages << PAGE_SHIFT) - offset); |
| iov_iter_advance(ii, frag_size); |
| |
| req->page_descs[req->num_pages].offset = offset; |
| fuse_page_descs_length_init(req, req->num_pages, npages); |
| |
| req->num_pages += npages; |
| req->page_descs[req->num_pages - 1].length -= |
| (npages << PAGE_SHIFT) - offset - frag_size; |
| |
| nbytes += frag_size; |
| } |
| |
| if (write) |
| req->in.argpages = 1; |
| else |
| req->out.argpages = 1; |
| |
| *nbytesp = nbytes; |
| |
| return 0; |
| } |
| |
| static inline int fuse_iter_npages(const struct iov_iter *ii_p) |
| { |
| struct iov_iter ii = *ii_p; |
| int npages = 0; |
| |
| while (iov_iter_count(&ii) && npages < FUSE_MAX_PAGES_PER_REQ) { |
| unsigned long user_addr = fuse_get_user_addr(&ii); |
| unsigned offset = user_addr & ~PAGE_MASK; |
| size_t frag_size = iov_iter_single_seg_count(&ii); |
| |
| npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| iov_iter_advance(&ii, frag_size); |
| } |
| |
| return min(npages, FUSE_MAX_PAGES_PER_REQ); |
| } |
| |
| ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov, |
| unsigned long nr_segs, size_t count, loff_t *ppos, |
| int write) |
| { |
| struct file *file = io->file; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| size_t nmax = write ? fc->max_write : fc->max_read; |
| loff_t pos = *ppos; |
| ssize_t res = 0; |
| struct fuse_req *req; |
| struct iov_iter ii; |
| |
| iov_iter_init(&ii, iov, nr_segs, count, 0); |
| |
| if (io->async) |
| req = fuse_get_req_for_background(fc, fuse_iter_npages(&ii)); |
| else |
| req = fuse_get_req(fc, fuse_iter_npages(&ii)); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| while (count) { |
| size_t nres; |
| fl_owner_t owner = current->files; |
| size_t nbytes = min(count, nmax); |
| int err = fuse_get_user_pages(req, &ii, &nbytes, write); |
| if (err) { |
| res = err; |
| break; |
| } |
| |
| if (write) |
| nres = fuse_send_write(req, io, pos, nbytes, owner); |
| else |
| nres = fuse_send_read(req, io, pos, nbytes, owner); |
| |
| if (!io->async) |
| fuse_release_user_pages(req, !write); |
| if (req->out.h.error) { |
| if (!res) |
| res = req->out.h.error; |
| break; |
| } else if (nres > nbytes) { |
| res = -EIO; |
| break; |
| } |
| count -= nres; |
| res += nres; |
| pos += nres; |
| if (nres != nbytes) |
| break; |
| if (count) { |
| fuse_put_request(fc, req); |
| if (io->async) |
| req = fuse_get_req_for_background(fc, |
| fuse_iter_npages(&ii)); |
| else |
| req = fuse_get_req(fc, fuse_iter_npages(&ii)); |
| if (IS_ERR(req)) |
| break; |
| } |
| } |
| if (!IS_ERR(req)) |
| fuse_put_request(fc, req); |
| if (res > 0) |
| *ppos = pos; |
| |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(fuse_direct_io); |
| |
| static ssize_t __fuse_direct_read(struct fuse_io_priv *io, |
| const struct iovec *iov, |
| unsigned long nr_segs, loff_t *ppos, |
| size_t count) |
| { |
| ssize_t res; |
| struct file *file = io->file; |
| struct inode *inode = file_inode(file); |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| res = fuse_direct_io(io, iov, nr_segs, count, ppos, 0); |
| |
| fuse_invalidate_attr(inode); |
| |
| return res; |
| } |
| |
| static ssize_t fuse_direct_read(struct file *file, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct fuse_io_priv io = { .async = 0, .file = file }; |
| struct iovec iov = { .iov_base = buf, .iov_len = count }; |
| return __fuse_direct_read(&io, &iov, 1, ppos, count); |
| } |
| |
| static ssize_t __fuse_direct_write(struct fuse_io_priv *io, |
| const struct iovec *iov, |
| unsigned long nr_segs, loff_t *ppos) |
| { |
| struct file *file = io->file; |
| struct inode *inode = file_inode(file); |
| size_t count = iov_length(iov, nr_segs); |
| ssize_t res; |
| |
| res = generic_write_checks(file, ppos, &count, 0); |
| if (!res) |
| res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1); |
| |
| fuse_invalidate_attr(inode); |
| |
| return res; |
| } |
| |
| static ssize_t fuse_direct_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count }; |
| struct inode *inode = file_inode(file); |
| ssize_t res; |
| struct fuse_io_priv io = { .async = 0, .file = file }; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| /* Don't allow parallel writes to the same file */ |
| mutex_lock(&inode->i_mutex); |
| res = __fuse_direct_write(&io, &iov, 1, ppos); |
| if (res > 0) |
| fuse_write_update_size(inode, *ppos); |
| mutex_unlock(&inode->i_mutex); |
| |
| return res; |
| } |
| |
| static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| int i; |
| |
| for (i = 0; i < req->num_pages; i++) |
| __free_page(req->pages[i]); |
| |
| if (req->ff) |
| fuse_file_put(req->ff, false); |
| } |
| |
| static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| struct inode *inode = req->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info; |
| int i; |
| |
| list_del(&req->writepages_entry); |
| for (i = 0; i < req->num_pages; i++) { |
| dec_bdi_stat(bdi, BDI_WRITEBACK); |
| dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP); |
| bdi_writeout_inc(bdi); |
| } |
| wake_up(&fi->page_waitq); |
| } |
| |
| /* 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); |
| struct fuse_write_in *inarg = &req->misc.write.in; |
| __u64 data_size = req->num_pages * PAGE_CACHE_SIZE; |
| |
| if (!fc->connected) |
| goto out_free; |
| |
| if (inarg->offset + data_size <= size) { |
| inarg->size = data_size; |
| } else if (inarg->offset < size) { |
| inarg->size = size - inarg->offset; |
| } else { |
| /* Got truncated off completely */ |
| goto out_free; |
| } |
| |
| req->in.args[1].size = inarg->size; |
| fi->writectr++; |
| 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); |
| } |
| |
| /* |
| * If fi->writectr is positive (no truncate or fsync going on) send |
| * all queued writepage requests. |
| * |
| * 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); |
| struct fuse_req *req; |
| |
| while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) { |
| req = list_entry(fi->queued_writes.next, struct fuse_req, list); |
| list_del_init(&req->list); |
| fuse_send_writepage(fc, req); |
| } |
| } |
| |
| static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req) |
| { |
| struct inode *inode = req->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| mapping_set_error(inode->i_mapping, req->out.h.error); |
| spin_lock(&fc->lock); |
| while (req->misc.write.next) { |
| struct fuse_req *next = req->misc.write.next; |
| req->misc.write.next = next->misc.write.next; |
| next->misc.write.next = NULL; |
| list_add(&next->writepages_entry, &fi->writepages); |
| list_add_tail(&next->list, &fi->queued_writes); |
| fuse_flush_writepages(inode); |
| } |
| fi->writectr--; |
| fuse_writepage_finish(fc, req); |
| spin_unlock(&fc->lock); |
| fuse_writepage_free(fc, req); |
| } |
| |
| static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc, |
| struct fuse_inode *fi) |
| { |
| struct fuse_file *ff = NULL; |
| |
| spin_lock(&fc->lock); |
| if (!WARN_ON(list_empty(&fi->write_files))) { |
| ff = list_entry(fi->write_files.next, struct fuse_file, |
| write_entry); |
| fuse_file_get(ff); |
| } |
| spin_unlock(&fc->lock); |
| |
| return ff; |
| } |
| |
| static int fuse_writepage_locked(struct page *page) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_req *req; |
| struct page *tmp_page; |
| int error = -ENOMEM; |
| |
| set_page_writeback(page); |
| |
| req = fuse_request_alloc_nofs(1); |
| if (!req) |
| goto err; |
| |
| req->background = 1; /* writeback always goes to bg_queue */ |
| tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
| if (!tmp_page) |
| goto err_free; |
| |
| error = -EIO; |
| req->ff = fuse_write_file_get(fc, fi); |
| if (!req->ff) |
| goto err_free; |
| |
| fuse_write_fill(req, req->ff, page_offset(page), 0); |
| |
| copy_highpage(tmp_page, page); |
| req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; |
| req->misc.write.next = NULL; |
| req->in.argpages = 1; |
| req->num_pages = 1; |
| req->pages[0] = tmp_page; |
| req->page_descs[0].offset = 0; |
| req->page_descs[0].length = PAGE_SIZE; |
| req->end = fuse_writepage_end; |
| req->inode = inode; |
| |
| inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK); |
| inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP); |
| |
| spin_lock(&fc->lock); |
| list_add(&req->writepages_entry, &fi->writepages); |
| list_add_tail(&req->list, &fi->queued_writes); |
| fuse_flush_writepages(inode); |
| spin_unlock(&fc->lock); |
| |
| end_page_writeback(page); |
| |
| return 0; |
| |
| err_free: |
| fuse_request_free(req); |
| err: |
| end_page_writeback(page); |
| return error; |
| } |
| |
| static int fuse_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| int err; |
| |
| if (fuse_page_is_writeback(page->mapping->host, page->index)) { |
| /* |
| * ->writepages() should be called for sync() and friends. We |
| * should only get here on direct reclaim and then we are |
| * allowed to skip a page which is already in flight |
| */ |
| WARN_ON(wbc->sync_mode == WB_SYNC_ALL); |
| |
| redirty_page_for_writepage(wbc, page); |
| return 0; |
| } |
| |
| err = fuse_writepage_locked(page); |
| unlock_page(page); |
| |
| return err; |
| } |
| |
| struct fuse_fill_wb_data { |
| struct fuse_req *req; |
| struct fuse_file *ff; |
| struct inode *inode; |
| struct page **orig_pages; |
| }; |
| |
| static void fuse_writepages_send(struct fuse_fill_wb_data *data) |
| { |
| struct fuse_req *req = data->req; |
| struct inode *inode = data->inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| int num_pages = req->num_pages; |
| int i; |
| |
| req->ff = fuse_file_get(data->ff); |
| spin_lock(&fc->lock); |
| list_add_tail(&req->list, &fi->queued_writes); |
| fuse_flush_writepages(inode); |
| spin_unlock(&fc->lock); |
| |
| for (i = 0; i < num_pages; i++) |
| end_page_writeback(data->orig_pages[i]); |
| } |
| |
| static bool fuse_writepage_in_flight(struct fuse_req *new_req, |
| struct page *page) |
| { |
| struct fuse_conn *fc = get_fuse_conn(new_req->inode); |
| struct fuse_inode *fi = get_fuse_inode(new_req->inode); |
| struct fuse_req *tmp; |
| struct fuse_req *old_req; |
| bool found = false; |
| pgoff_t curr_index; |
| |
| BUG_ON(new_req->num_pages != 0); |
| |
| spin_lock(&fc->lock); |
| list_del(&new_req->writepages_entry); |
| new_req->num_pages = 1; |
| list_for_each_entry(old_req, &fi->writepages, writepages_entry) { |
| BUG_ON(old_req->inode != new_req->inode); |
| curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT; |
| if (curr_index <= page->index && |
| page->index < curr_index + old_req->num_pages) { |
| found = true; |
| break; |
| } |
| } |
| if (!found) |
| goto out_unlock; |
| |
| for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) { |
| BUG_ON(tmp->inode != new_req->inode); |
| curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT; |
| if (tmp->num_pages == 1 && |
| curr_index == page->index) { |
| old_req = tmp; |
| } |
| } |
| |
| if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT || |
| old_req->state == FUSE_REQ_PENDING)) { |
| copy_highpage(old_req->pages[0], page); |
| spin_unlock(&fc->lock); |
| |
| dec_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK); |
| dec_zone_page_state(page, NR_WRITEBACK_TEMP); |
| fuse_writepage_free(fc, new_req); |
| fuse_request_free(new_req); |
| goto out; |
| } else { |
| new_req->misc.write.next = old_req->misc.write.next; |
| old_req->misc.write.next = new_req; |
| } |
| out_unlock: |
| spin_unlock(&fc->lock); |
| out: |
| return found; |
| } |
| |
| static int fuse_writepages_fill(struct page *page, |
| struct writeback_control *wbc, void *_data) |
| { |
| struct fuse_fill_wb_data *data = _data; |
| struct fuse_req *req = data->req; |
| struct inode *inode = data->inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct page *tmp_page; |
| bool is_writeback; |
| int err; |
| |
| if (!data->ff) { |
| err = -EIO; |
| data->ff = fuse_write_file_get(fc, get_fuse_inode(inode)); |
| if (!data->ff) |
| goto out_unlock; |
| } |
| |
| /* |
| * Being under writeback is unlikely but possible. For example direct |
| * read to an mmaped fuse file will set the page dirty twice; once when |
| * the pages are faulted with get_user_pages(), and then after the read |
| * completed. |
| */ |
| is_writeback = fuse_page_is_writeback(inode, page->index); |
| |
| if (req && req->num_pages && |
| (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ || |
| (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write || |
| data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) { |
| fuse_writepages_send(data); |
| data->req = NULL; |
| } |
| err = -ENOMEM; |
| tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
| if (!tmp_page) |
| goto out_unlock; |
| |
| /* |
| * The page must not be redirtied until the writeout is completed |
| * (i.e. userspace has sent a reply to the write request). Otherwise |
| * there could be more than one temporary page instance for each real |
| * page. |
| * |
| * This is ensured by holding the page lock in page_mkwrite() while |
| * checking fuse_page_is_writeback(). We already hold the page lock |
| * since clear_page_dirty_for_io() and keep it held until we add the |
| * request to the fi->writepages list and increment req->num_pages. |
| * After this fuse_page_is_writeback() will indicate that the page is |
| * under writeback, so we can release the page lock. |
| */ |
| if (data->req == NULL) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| err = -ENOMEM; |
| req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ); |
| if (!req) { |
| __free_page(tmp_page); |
| goto out_unlock; |
| } |
| |
| fuse_write_fill(req, data->ff, page_offset(page), 0); |
| req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; |
| req->misc.write.next = NULL; |
| req->in.argpages = 1; |
| req->background = 1; |
| req->num_pages = 0; |
| req->end = fuse_writepage_end; |
| req->inode = inode; |
| |
| spin_lock(&fc->lock); |
| list_add(&req->writepages_entry, &fi->writepages); |
| spin_unlock(&fc->lock); |
| |
| data->req = req; |
| } |
| set_page_writeback(page); |
| |
| copy_highpage(tmp_page, page); |
| req->pages[req->num_pages] = tmp_page; |
| req->page_descs[req->num_pages].offset = 0; |
| req->page_descs[req->num_pages].length = PAGE_SIZE; |
| |
| inc_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK); |
| inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP); |
| |
| err = 0; |
| if (is_writeback && fuse_writepage_in_flight(req, page)) { |
| end_page_writeback(page); |
| data->req = NULL; |
| goto out_unlock; |
| } |
| data->orig_pages[req->num_pages] = page; |
| |
| /* |
| * Protected by fc->lock against concurrent access by |
| * fuse_page_is_writeback(). |
| */ |
| spin_lock(&fc->lock); |
| req->num_pages++; |
| spin_unlock(&fc->lock); |
| |
| out_unlock: |
| unlock_page(page); |
| |
| return err; |
| } |
| |
| static int fuse_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| struct inode *inode = mapping->host; |
| struct fuse_fill_wb_data data; |
| int err; |
| |
| err = -EIO; |
| if (is_bad_inode(inode)) |
| goto out; |
| |
| data.inode = inode; |
| data.req = NULL; |
| data.ff = NULL; |
| |
| err = -ENOMEM; |
| data.orig_pages = kzalloc(sizeof(struct page *) * |
| FUSE_MAX_PAGES_PER_REQ, |
| GFP_NOFS); |
| if (!data.orig_pages) |
| goto out; |
| |
| err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data); |
| if (data.req) { |
| /* Ignore errors if we can write at least one page */ |
| BUG_ON(!data.req->num_pages); |
| fuse_writepages_send(&data); |
| err = 0; |
| } |
| if (data.ff) |
| fuse_file_put(data.ff, false); |
| |
| kfree(data.orig_pages); |
| out: |
| return err; |
| } |
| |
| static int fuse_launder_page(struct page *page) |
| { |
| int err = 0; |
| if (clear_page_dirty_for_io(page)) { |
| struct inode *inode = page->mapping->host; |
| err = fuse_writepage_locked(page); |
| if (!err) |
| fuse_wait_on_page_writeback(inode, page->index); |
| } |
| return err; |
| } |
| |
| /* |
| * Write back dirty pages now, because there may not be any suitable |
| * open files later |
| */ |
| static void fuse_vma_close(struct vm_area_struct *vma) |
| { |
| filemap_write_and_wait(vma->vm_file->f_mapping); |
| } |
| |
| /* |
| * Wait for writeback against this page to complete before allowing it |
| * to be marked dirty again, and hence written back again, possibly |
| * before the previous writepage completed. |
| * |
| * Block here, instead of in ->writepage(), so that the userspace fs |
| * can only block processes actually operating on the filesystem. |
| * |
| * Otherwise unprivileged userspace fs would be able to block |
| * unrelated: |
| * |
| * - page migration |
| * - sync(2) |
| * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER |
| */ |
| static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct page *page = vmf->page; |
| struct inode *inode = file_inode(vma->vm_file); |
| |
| file_update_time(vma->vm_file); |
| lock_page(page); |
| if (page->mapping != inode->i_mapping) { |
| unlock_page(page); |
| return VM_FAULT_NOPAGE; |
| } |
| |
| fuse_wait_on_page_writeback(inode, page->index); |
| return VM_FAULT_LOCKED; |
| } |
| |
| static const struct vm_operations_struct fuse_file_vm_ops = { |
| .close = fuse_vma_close, |
| .fault = filemap_fault, |
| .page_mkwrite = fuse_page_mkwrite, |
| .remap_pages = generic_file_remap_pages, |
| }; |
| |
| static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_file *ff = file->private_data; |
| /* |
| * file may be written through mmap, so chain it onto the |
| * inodes's write_file list |
| */ |
| spin_lock(&fc->lock); |
| if (list_empty(&ff->write_entry)) |
| list_add(&ff->write_entry, &fi->write_files); |
| spin_unlock(&fc->lock); |
| } |
| file_accessed(file); |
| vma->vm_ops = &fuse_file_vm_ops; |
| return 0; |
| } |
| |
| static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| /* Can't provide the coherency needed for MAP_SHARED */ |
| if (vma->vm_flags & VM_MAYSHARE) |
| return -ENODEV; |
| |
| invalidate_inode_pages2(file->f_mapping); |
| |
| return generic_file_mmap(file, vma); |
| } |
| |
| static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, |
| struct file_lock *fl) |
| { |
| switch (ffl->type) { |
| case F_UNLCK: |
| break; |
| |
| case F_RDLCK: |
| case F_WRLCK: |
| if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX || |
| ffl->end < ffl->start) |
| return -EIO; |
| |
| fl->fl_start = ffl->start; |
| fl->fl_end = ffl->end; |
| fl->fl_pid = ffl->pid; |
| break; |
| |
| default: |
| return -EIO; |
| } |
| fl->fl_type = ffl->type; |
| return 0; |
| } |
| |
| static void fuse_lk_fill(struct fuse_req *req, struct file *file, |
| const struct file_lock *fl, int opcode, pid_t pid, |
| int flock) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| struct fuse_lk_in *arg = &req->misc.lk_in; |
| |
| arg->fh = ff->fh; |
| arg->owner = fuse_lock_owner_id(fc, fl->fl_owner); |
| arg->lk.start = fl->fl_start; |
| arg->lk.end = fl->fl_end; |
| arg->lk.type = fl->fl_type; |
| arg->lk.pid = pid; |
| if (flock) |
| arg->lk_flags |= FUSE_LK_FLOCK; |
| req->in.h.opcode = opcode; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(*arg); |
| req->in.args[0].value = arg; |
| } |
| |
| static int fuse_getlk(struct file *file, struct file_lock *fl) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| struct fuse_lk_out outarg; |
| int err; |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0); |
| 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) |
| err = convert_fuse_file_lock(&outarg.lk, fl); |
| |
| return err; |
| } |
| |
| static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK; |
| pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0; |
| int err; |
| |
| if (fl->fl_lmops && fl->fl_lmops->lm_grant) { |
| /* NLM needs asynchronous locks, which we don't support yet */ |
| return -ENOLCK; |
| } |
| |
| /* Unlock on close is handled by the flush method */ |
| if (fl->fl_flags & FL_CLOSE) |
| return 0; |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| fuse_lk_fill(req, file, fl, opcode, pid, flock); |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| /* locking is restartable */ |
| if (err == -EINTR) |
| err = -ERESTARTSYS; |
| fuse_put_request(fc, req); |
| return err; |
| } |
| |
| static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| int err; |
| |
| if (cmd == F_CANCELLK) { |
| err = 0; |
| } else if (cmd == F_GETLK) { |
| if (fc->no_lock) { |
| posix_test_lock(file, fl); |
| err = 0; |
| } else |
| err = fuse_getlk(file, fl); |
| } else { |
| if (fc->no_lock) |
| err = posix_lock_file(file, fl, NULL); |
| else |
| err = fuse_setlk(file, fl, 0); |
| } |
| return err; |
| } |
| |
| static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| int err; |
| |
| if (fc->no_flock) { |
| err = flock_lock_file_wait(file, fl); |
| } else { |
| struct fuse_file *ff = file->private_data; |
| |
| /* emulate flock with POSIX locks */ |
| fl->fl_owner = (fl_owner_t) file; |
| ff->flock = true; |
| err = fuse_setlk(file, fl, 1); |
| } |
| |
| return err; |
| } |
| |
| static sector_t fuse_bmap(struct address_space *mapping, sector_t block) |
| { |
| struct inode *inode = mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| struct fuse_bmap_in inarg; |
| struct fuse_bmap_out outarg; |
| int err; |
| |
| if (!inode->i_sb->s_bdev || fc->no_bmap) |
| return 0; |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) |
| return 0; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.block = block; |
| inarg.blocksize = inode->i_sb->s_blocksize; |
| req->in.h.opcode = FUSE_BMAP; |
| 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 == -ENOSYS) |
| fc->no_bmap = 1; |
| |
| return err ? 0 : outarg.block; |
| } |
| |
| static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) |
| { |
| loff_t retval; |
| struct inode *inode = file_inode(file); |
| |
| /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */ |
| if (whence == SEEK_CUR || whence == SEEK_SET) |
| return generic_file_llseek(file, offset, whence); |
| |
| mutex_lock(&inode->i_mutex); |
| retval = fuse_update_attributes(inode, NULL, file, NULL); |
| if (!retval) |
| retval = generic_file_llseek(file, offset, whence); |
| mutex_unlock(&inode->i_mutex); |
| |
| 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; |
| |
| kaddr = 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(page); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * CUSE servers compiled on 32bit broke on 64bit kernels because the |
| * ABI was defined to be 'struct iovec' which is different on 32bit |
| * and 64bit. Fortunately we can determine which structure the server |
| * used from the size of the reply. |
| */ |
| static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, |
| size_t transferred, unsigned count, |
| bool is_compat) |
| { |
| #ifdef CONFIG_COMPAT |
| if (count * sizeof(struct compat_iovec) == transferred) { |
| struct compat_iovec *ciov = src; |
| unsigned i; |
| |
| /* |
| * With this interface a 32bit server cannot support |
| * non-compat (i.e. ones coming from 64bit apps) ioctl |
| * requests |
| */ |
| if (!is_compat) |
| return -EINVAL; |
| |
| for (i = 0; i < count; i++) { |
| dst[i].iov_base = compat_ptr(ciov[i].iov_base); |
| dst[i].iov_len = ciov[i].iov_len; |
| } |
| return 0; |
| } |
| #endif |
| |
| if (count * sizeof(struct iovec) != transferred) |
| return -EIO; |
| |
| memcpy(dst, src, transferred); |
| return 0; |
| } |
| |
| /* Make sure iov_length() won't overflow */ |
| static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) |
| { |
| size_t n; |
| u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; |
| |
| for (n = 0; n < count; n++, iov++) { |
| if (iov->iov_len > (size_t) max) |
| return -ENOMEM; |
| max -= iov->iov_len; |
| } |
| return 0; |
| } |
| |
| static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, |
| void *src, size_t transferred, unsigned count, |
| bool is_compat) |
| { |
| unsigned i; |
| struct fuse_ioctl_iovec *fiov = src; |
| |
| if (fc->minor < 16) { |
| return fuse_copy_ioctl_iovec_old(dst, src, transferred, |
| count, is_compat); |
| } |
| |
| if (count * sizeof(struct fuse_ioctl_iovec) != transferred) |
| return -EIO; |
| |
| for (i = 0; i < count; i++) { |
| /* Did the server supply an inappropriate value? */ |
| if (fiov[i].base != (unsigned long) fiov[i].base || |
| fiov[i].len != (unsigned long) fiov[i].len) |
| return -EIO; |
| |
| dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; |
| dst[i].iov_len = (size_t) fiov[i].len; |
| |
| #ifdef CONFIG_COMPAT |
| if (is_compat && |
| (ptr_to_compat(dst[i].iov_base) != fiov[i].base || |
| (compat_size_t) dst[i].iov_len != fiov[i].len)) |
| return -EIO; |
| #endif |
| } |
| |
| 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. |
| */ |
| long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, |
| unsigned int flags) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| 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 iovec *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; |
| |
| #if BITS_PER_LONG == 32 |
| inarg.flags |= FUSE_IOCTL_32BIT; |
| #else |
| if (flags & FUSE_IOCTL_COMPAT) |
| inarg.flags |= FUSE_IOCTL_32BIT; |
| #endif |
| |
| /* assume all the iovs returned by client always fits in a page */ |
| BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); |
| |
| err = -ENOMEM; |
| pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL); |
| iov_page = (struct iovec *) __get_free_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 = 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, num_pages); |
| 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; |
| fuse_page_descs_length_init(req, 0, req->num_pages); |
| |
| /* okay, let's send it to the client */ |
| req->in.h.opcode = FUSE_IOCTL; |
| req->in.h.nodeid = ff->nodeid; |
| 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) { |
| void *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; |
| |
| vaddr = kmap_atomic(pages[0]); |
| err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr, |
| transferred, in_iovs + out_iovs, |
| (flags & FUSE_IOCTL_COMPAT) != 0); |
| kunmap_atomic(vaddr); |
| if (err) |
| goto out; |
| |
| in_iov = iov_page; |
| out_iov = in_iov + in_iovs; |
| |
| err = fuse_verify_ioctl_iov(in_iov, in_iovs); |
| if (err) |
| goto out; |
| |
| err = fuse_verify_ioctl_iov(out_iov, out_iovs); |
| if (err) |
| goto out; |
| |
| 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); |
| free_page((unsigned long) iov_page); |
| while (num_pages) |
| __free_page(pages[--num_pages]); |
| kfree(pages); |
| |
| return err ? err : outarg.result; |
| } |
| EXPORT_SYMBOL_GPL(fuse_do_ioctl); |
| |
| long fuse_ioctl_common(struct file *file, unsigned int cmd, |
| unsigned long arg, unsigned int flags) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (!fuse_allow_current_process(fc)) |
| return -EACCES; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| return fuse_do_ioctl(file, cmd, arg, flags); |
| } |
| |
| static long fuse_file_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return fuse_ioctl_common(file, cmd, arg, 0); |
| } |
| |
| static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return fuse_ioctl_common(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); |
| } |
| |
| unsigned fuse_file_poll(struct file *file, poll_table *wait) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| 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); |
| inarg.events = (__u32)poll_requested_events(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_nopages(fc); |
| if (IS_ERR(req)) |
| return POLLERR; |
| |
| req->in.h.opcode = FUSE_POLL; |
| req->in.h.nodeid = ff->nodeid; |
| 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; |
| } |
| EXPORT_SYMBOL_GPL(fuse_file_poll); |
| |
| /* |
| * 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 void fuse_do_truncate(struct file *file) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct iattr attr; |
| |
| attr.ia_valid = ATTR_SIZE; |
| attr.ia_size = i_size_read(inode); |
| |
| attr.ia_file = file; |
| attr.ia_valid |= ATTR_FILE; |
| |
| fuse_do_setattr(inode, &attr, file); |
| } |
| |
| static inline loff_t fuse_round_up(loff_t off) |
| { |
| return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); |
| } |
| |
| static ssize_t |
| fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, |
| loff_t offset, unsigned long nr_segs) |
| { |
| ssize_t ret = 0; |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| bool async_dio = ff->fc->async_dio; |
| loff_t pos = 0; |
| struct inode *inode; |
| loff_t i_size; |
| size_t count = iov_length(iov, nr_segs); |
| struct fuse_io_priv *io; |
| |
| pos = offset; |
| inode = file->f_mapping->host; |
| i_size = i_size_read(inode); |
| |
| /* optimization for short read */ |
| if (async_dio && rw != WRITE && offset + count > i_size) { |
| if (offset >= i_size) |
| return 0; |
| count = min_t(loff_t, count, fuse_round_up(i_size - offset)); |
| } |
| |
| io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL); |
| if (!io) |
| return -ENOMEM; |
| spin_lock_init(&io->lock); |
| io->reqs = 1; |
| io->bytes = -1; |
| io->size = 0; |
| io->offset = offset; |
| io->write = (rw == WRITE); |
| io->err = 0; |
| io->file = file; |
| /* |
| * By default, we want to optimize all I/Os with async request |
| * submission to the client filesystem if supported. |
| */ |
| io->async = async_dio; |
| io->iocb = iocb; |
| |
| /* |
| * We cannot asynchronously extend the size of a file. We have no method |
| * to wait on real async I/O requests, so we must submit this request |
| * synchronously. |
| */ |
| if (!is_sync_kiocb(iocb) && (offset + count > i_size) && rw == WRITE) |
| io->async = false; |
| |
| if (rw == WRITE) |
| ret = __fuse_direct_write(io, iov, nr_segs, &pos); |
| else |
| ret = __fuse_direct_read(io, iov, nr_segs, &pos, count); |
| |
| if (io->async) { |
| fuse_aio_complete(io, ret < 0 ? ret : 0, -1); |
| |
| /* we have a non-extending, async request, so return */ |
| if (!is_sync_kiocb(iocb)) |
| return -EIOCBQUEUED; |
| |
| ret = wait_on_sync_kiocb(iocb); |
| } else { |
| kfree(io); |
| } |
| |
| if (rw == WRITE) { |
| if (ret > 0) |
| fuse_write_update_size(inode, pos); |
| else if (ret < 0 && offset + count > i_size) |
| fuse_do_truncate(file); |
| } |
| |
| return ret; |
| } |
| |
| static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, |
| loff_t length) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct inode *inode = file->f_inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_req *req; |
| struct fuse_fallocate_in inarg = { |
| .fh = ff->fh, |
| .offset = offset, |
| .length = length, |
| .mode = mode |
| }; |
| int err; |
| bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) || |
| (mode & FALLOC_FL_PUNCH_HOLE); |
| |
| if (fc->no_fallocate) |
| return -EOPNOTSUPP; |
| |
| if (lock_inode) { |
| mutex_lock(&inode->i_mutex); |
| if (mode & FALLOC_FL_PUNCH_HOLE) { |
| loff_t endbyte = offset + length - 1; |
| err = filemap_write_and_wait_range(inode->i_mapping, |
| offset, endbyte); |
| if (err) |
| goto out; |
| |
| fuse_sync_writes(inode); |
| } |
| } |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| |
| req = fuse_get_req_nopages(fc); |
| if (IS_ERR(req)) { |
| err = PTR_ERR(req); |
| goto out; |
| } |
| |
| req->in.h.opcode = FUSE_FALLOCATE; |
| req->in.h.nodeid = ff->nodeid; |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(inarg); |
| req->in.args[0].value = &inarg; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| if (err == -ENOSYS) { |
| fc->no_fallocate = 1; |
| err = -EOPNOTSUPP; |
| } |
| fuse_put_request(fc, req); |
| |
| if (err) |
| goto out; |
| |
| /* we could have extended the file */ |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) |
| fuse_write_update_size(inode, offset + length); |
| |
| if (mode & FALLOC_FL_PUNCH_HOLE) |
| truncate_pagecache_range(inode, offset, offset + length - 1); |
| |
| fuse_invalidate_attr(inode); |
| |
| out: |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) |
| clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| |
| if (lock_inode) |
| mutex_unlock(&inode->i_mutex); |
| |
| return err; |
| } |
| |
| static const struct file_operations fuse_file_operations = { |
| .llseek = fuse_file_llseek, |
| .read = do_sync_read, |
| .aio_read = fuse_file_aio_read, |
| .write = do_sync_write, |
| .aio_write = fuse_file_aio_write, |
| .mmap = fuse_file_mmap, |
| .open = fuse_open, |
| .flush = fuse_flush, |
| .release = fuse_release, |
| .fsync = fuse_fsync, |
| .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, |
| .fallocate = fuse_file_fallocate, |
| }; |
| |
| static const struct file_operations fuse_direct_io_file_operations = { |
| .llseek = fuse_file_llseek, |
| .read = fuse_direct_read, |
| .write = fuse_direct_write, |
| .mmap = fuse_direct_mmap, |
| .open = fuse_open, |
| .flush = fuse_flush, |
| .release = fuse_release, |
| .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, |
| .fallocate = fuse_file_fallocate, |
| /* no splice_read */ |
| }; |
| |
| static const struct address_space_operations fuse_file_aops = { |
| .readpage = fuse_readpage, |
| .writepage = fuse_writepage, |
| .writepages = fuse_writepages, |
| .launder_page = fuse_launder_page, |
| .readpages = fuse_readpages, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .bmap = fuse_bmap, |
| .direct_IO = fuse_direct_IO, |
| }; |
| |
| void fuse_init_file_inode(struct inode *inode) |
| { |
| inode->i_fop = &fuse_file_operations; |
| inode->i_data.a_ops = &fuse_file_aops; |
| } |