| /* |
| 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/sched/signal.h> |
| #include <linux/module.h> |
| #include <linux/compat.h> |
| #include <linux/swap.h> |
| #include <linux/falloc.h> |
| #include <linux/uio.h> |
| #include <linux/fs.h> |
| |
| static struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags, |
| struct fuse_page_desc **desc) |
| { |
| struct page **pages; |
| |
| pages = kzalloc(npages * (sizeof(struct page *) + |
| sizeof(struct fuse_page_desc)), flags); |
| *desc = (void *) (pages + npages); |
| |
| return pages; |
| } |
| |
| 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; |
| FUSE_ARGS(args); |
| |
| 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; |
| args.opcode = opcode; |
| args.nodeid = nodeid; |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(*outargp); |
| args.out_args[0].value = outargp; |
| |
| return fuse_simple_request(fc, &args); |
| } |
| |
| struct fuse_release_args { |
| struct fuse_args args; |
| struct fuse_release_in inarg; |
| struct inode *inode; |
| }; |
| |
| struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) |
| { |
| struct fuse_file *ff; |
| |
| ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL_ACCOUNT); |
| if (unlikely(!ff)) |
| return NULL; |
| |
| ff->fc = fc; |
| ff->release_args = kzalloc(sizeof(*ff->release_args), |
| GFP_KERNEL_ACCOUNT); |
| if (!ff->release_args) { |
| kfree(ff); |
| return NULL; |
| } |
| |
| INIT_LIST_HEAD(&ff->write_entry); |
| mutex_init(&ff->readdir.lock); |
| refcount_set(&ff->count, 1); |
| RB_CLEAR_NODE(&ff->polled_node); |
| init_waitqueue_head(&ff->poll_wait); |
| |
| ff->kh = atomic64_inc_return(&fc->khctr); |
| |
| return ff; |
| } |
| |
| void fuse_file_free(struct fuse_file *ff) |
| { |
| kfree(ff->release_args); |
| mutex_destroy(&ff->readdir.lock); |
| kfree(ff); |
| } |
| |
| static struct fuse_file *fuse_file_get(struct fuse_file *ff) |
| { |
| refcount_inc(&ff->count); |
| return ff; |
| } |
| |
| static void fuse_release_end(struct fuse_conn *fc, struct fuse_args *args, |
| int error) |
| { |
| struct fuse_release_args *ra = container_of(args, typeof(*ra), args); |
| |
| iput(ra->inode); |
| kfree(ra); |
| } |
| |
| static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir) |
| { |
| if (refcount_dec_and_test(&ff->count)) { |
| struct fuse_args *args = &ff->release_args->args; |
| |
| if (isdir ? ff->fc->no_opendir : ff->fc->no_open) { |
| /* Do nothing when client does not implement 'open' */ |
| fuse_release_end(ff->fc, args, 0); |
| } else if (sync) { |
| fuse_simple_request(ff->fc, args); |
| fuse_release_end(ff->fc, args, 0); |
| } else { |
| args->end = fuse_release_end; |
| if (fuse_simple_background(ff->fc, args, |
| GFP_KERNEL | __GFP_NOFAIL)) |
| fuse_release_end(ff->fc, args, -ENOTCONN); |
| } |
| kfree(ff); |
| } |
| } |
| |
| int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, |
| bool isdir) |
| { |
| struct fuse_file *ff; |
| int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; |
| |
| ff = fuse_file_alloc(fc); |
| if (!ff) |
| return -ENOMEM; |
| |
| ff->fh = 0; |
| /* Default for no-open */ |
| ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0); |
| if (isdir ? !fc->no_opendir : !fc->no_open) { |
| struct fuse_open_out outarg; |
| int err; |
| |
| err = fuse_send_open(fc, nodeid, file, opcode, &outarg); |
| if (!err) { |
| ff->fh = outarg.fh; |
| ff->open_flags = outarg.open_flags; |
| |
| } else if (err != -ENOSYS) { |
| fuse_file_free(ff); |
| return err; |
| } else { |
| if (isdir) |
| fc->no_opendir = 1; |
| else |
| fc->no_open = 1; |
| } |
| } |
| |
| if (isdir) |
| ff->open_flags &= ~FOPEN_DIRECT_IO; |
| |
| ff->nodeid = nodeid; |
| file->private_data = ff; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(fuse_do_open); |
| |
| static void fuse_link_write_file(struct file *file) |
| { |
| struct inode *inode = file_inode(file); |
| 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(&fi->lock); |
| if (list_empty(&ff->write_entry)) |
| list_add(&ff->write_entry, &fi->write_files); |
| spin_unlock(&fi->lock); |
| } |
| |
| 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_KEEP_CACHE)) |
| invalidate_inode_pages2(inode->i_mapping); |
| if (ff->open_flags & FOPEN_STREAM) |
| stream_open(inode, file); |
| else 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(&fi->lock); |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| i_size_write(inode, 0); |
| spin_unlock(&fi->lock); |
| fuse_invalidate_attr(inode); |
| if (fc->writeback_cache) |
| file_update_time(file); |
| } |
| if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache) |
| fuse_link_write_file(file); |
| } |
| |
| int fuse_open_common(struct inode *inode, struct file *file, bool isdir) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| int err; |
| bool is_wb_truncate = (file->f_flags & O_TRUNC) && |
| fc->atomic_o_trunc && |
| fc->writeback_cache; |
| |
| err = generic_file_open(inode, file); |
| if (err) |
| return err; |
| |
| if (is_wb_truncate) { |
| inode_lock(inode); |
| fuse_set_nowrite(inode); |
| } |
| |
| err = fuse_do_open(fc, get_node_id(inode), file, isdir); |
| |
| if (!err) |
| fuse_finish_open(inode, file); |
| |
| if (is_wb_truncate) { |
| fuse_release_nowrite(inode); |
| inode_unlock(inode); |
| } |
| |
| return err; |
| } |
| |
| static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff, |
| int flags, int opcode) |
| { |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_release_args *ra = ff->release_args; |
| |
| /* Inode is NULL on error path of fuse_create_open() */ |
| if (likely(fi)) { |
| spin_lock(&fi->lock); |
| list_del(&ff->write_entry); |
| spin_unlock(&fi->lock); |
| } |
| spin_lock(&fc->lock); |
| 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); |
| |
| ra->inarg.fh = ff->fh; |
| ra->inarg.flags = flags; |
| ra->args.in_numargs = 1; |
| ra->args.in_args[0].size = sizeof(struct fuse_release_in); |
| ra->args.in_args[0].value = &ra->inarg; |
| ra->args.opcode = opcode; |
| ra->args.nodeid = ff->nodeid; |
| ra->args.force = true; |
| ra->args.nocreds = true; |
| } |
| |
| void fuse_release_common(struct file *file, bool isdir) |
| { |
| struct fuse_inode *fi = get_fuse_inode(file_inode(file)); |
| struct fuse_file *ff = file->private_data; |
| struct fuse_release_args *ra = ff->release_args; |
| int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE; |
| |
| fuse_prepare_release(fi, ff, file->f_flags, opcode); |
| |
| if (ff->flock) { |
| ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; |
| ra->inarg.lock_owner = fuse_lock_owner_id(ff->fc, |
| (fl_owner_t) file); |
| } |
| /* Hold inode until release is finished */ |
| ra->inode = igrab(file_inode(file)); |
| |
| /* |
| * 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, isdir); |
| } |
| |
| 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) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| /* see fuse_vma_close() for !writeback_cache case */ |
| if (fc->writeback_cache) |
| write_inode_now(inode, 1); |
| |
| fuse_release_common(file, false); |
| |
| /* return value is ignored by VFS */ |
| return 0; |
| } |
| |
| void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags) |
| { |
| WARN_ON(refcount_read(&ff->count) > 1); |
| fuse_prepare_release(fi, ff, flags, FUSE_RELEASE); |
| /* |
| * iput(NULL) is a no-op and since the refcount is 1 and everything's |
| * synchronous, we are fine with not doing igrab() here" |
| */ |
| fuse_file_put(ff, true, false); |
| } |
| 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); |
| } |
| |
| struct fuse_writepage_args { |
| struct fuse_io_args ia; |
| struct rb_node writepages_entry; |
| struct list_head queue_entry; |
| struct fuse_writepage_args *next; |
| struct inode *inode; |
| }; |
| |
| static struct fuse_writepage_args *fuse_find_writeback(struct fuse_inode *fi, |
| pgoff_t idx_from, pgoff_t idx_to) |
| { |
| struct rb_node *n; |
| |
| n = fi->writepages.rb_node; |
| |
| while (n) { |
| struct fuse_writepage_args *wpa; |
| pgoff_t curr_index; |
| |
| wpa = rb_entry(n, struct fuse_writepage_args, writepages_entry); |
| WARN_ON(get_fuse_inode(wpa->inode) != fi); |
| curr_index = wpa->ia.write.in.offset >> PAGE_SHIFT; |
| if (idx_from >= curr_index + wpa->ia.ap.num_pages) |
| n = n->rb_right; |
| else if (idx_to < curr_index) |
| n = n->rb_left; |
| else |
| return wpa; |
| } |
| return NULL; |
| } |
| |
| /* |
| * Check if any page in a range 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_range_is_writeback(struct inode *inode, pgoff_t idx_from, |
| pgoff_t idx_to) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| bool found; |
| |
| spin_lock(&fi->lock); |
| found = fuse_find_writeback(fi, idx_from, idx_to); |
| spin_unlock(&fi->lock); |
| |
| return found; |
| } |
| |
| static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) |
| { |
| return fuse_range_is_writeback(inode, index, index); |
| } |
| |
| /* |
| * 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 void 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)); |
| } |
| |
| /* |
| * 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); |
| } |
| |
| 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_flush_in inarg; |
| FUSE_ARGS(args); |
| int err; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| err = write_inode_now(inode, 1); |
| if (err) |
| return err; |
| |
| inode_lock(inode); |
| fuse_sync_writes(inode); |
| inode_unlock(inode); |
| |
| err = filemap_check_errors(file->f_mapping); |
| if (err) |
| return err; |
| |
| err = 0; |
| if (fc->no_flush) |
| goto inval_attr_out; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.fh = ff->fh; |
| inarg.lock_owner = fuse_lock_owner_id(fc, id); |
| args.opcode = FUSE_FLUSH; |
| args.nodeid = get_node_id(inode); |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.force = true; |
| |
| err = fuse_simple_request(fc, &args); |
| if (err == -ENOSYS) { |
| fc->no_flush = 1; |
| err = 0; |
| } |
| |
| inval_attr_out: |
| /* |
| * In memory i_blocks is not maintained by fuse, if writeback cache is |
| * enabled, i_blocks from cached attr may not be accurate. |
| */ |
| if (!err && fc->writeback_cache) |
| fuse_invalidate_attr(inode); |
| return err; |
| } |
| |
| int fuse_fsync_common(struct file *file, loff_t start, loff_t end, |
| int datasync, int opcode) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| FUSE_ARGS(args); |
| struct fuse_fsync_in inarg; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.fh = ff->fh; |
| inarg.fsync_flags = datasync ? FUSE_FSYNC_FDATASYNC : 0; |
| args.opcode = opcode; |
| args.nodeid = get_node_id(inode); |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| return fuse_simple_request(fc, &args); |
| } |
| |
| static int fuse_fsync(struct file *file, loff_t start, loff_t end, |
| int datasync) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| int err; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| inode_lock(inode); |
| |
| /* |
| * Start writeback against all dirty pages of the inode, then |
| * wait for all outstanding writes, before sending the FSYNC |
| * request. |
| */ |
| err = file_write_and_wait_range(file, start, end); |
| if (err) |
| goto out; |
| |
| fuse_sync_writes(inode); |
| |
| /* |
| * Due to implementation of fuse writeback |
| * file_write_and_wait_range() does not catch errors. |
| * We have to do this directly after fuse_sync_writes() |
| */ |
| err = file_check_and_advance_wb_err(file); |
| if (err) |
| goto out; |
| |
| err = sync_inode_metadata(inode, 1); |
| if (err) |
| goto out; |
| |
| if (fc->no_fsync) |
| goto out; |
| |
| err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNC); |
| if (err == -ENOSYS) { |
| fc->no_fsync = 1; |
| err = 0; |
| } |
| out: |
| inode_unlock(inode); |
| |
| return err; |
| } |
| |
| void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos, |
| size_t count, int opcode) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_args *args = &ia->ap.args; |
| |
| ia->read.in.fh = ff->fh; |
| ia->read.in.offset = pos; |
| ia->read.in.size = count; |
| ia->read.in.flags = file->f_flags; |
| args->opcode = opcode; |
| args->nodeid = ff->nodeid; |
| args->in_numargs = 1; |
| args->in_args[0].size = sizeof(ia->read.in); |
| args->in_args[0].value = &ia->read.in; |
| args->out_argvar = true; |
| args->out_numargs = 1; |
| args->out_args[0].size = count; |
| } |
| |
| static void fuse_release_user_pages(struct fuse_args_pages *ap, |
| bool should_dirty) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < ap->num_pages; i++) { |
| if (should_dirty) |
| set_page_dirty_lock(ap->pages[i]); |
| put_page(ap->pages[i]); |
| } |
| } |
| |
| static void fuse_io_release(struct kref *kref) |
| { |
| kfree(container_of(kref, struct fuse_io_priv, refcnt)); |
| } |
| |
| static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io) |
| { |
| if (io->err) |
| return io->err; |
| |
| if (io->bytes >= 0 && io->write) |
| return -EIO; |
| |
| return io->bytes < 0 ? io->size : io->bytes; |
| } |
| |
| /** |
| * 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; |
| if (!left && io->blocking) |
| complete(io->done); |
| spin_unlock(&io->lock); |
| |
| if (!left && !io->blocking) { |
| ssize_t res = fuse_get_res_by_io(io); |
| |
| if (res >= 0) { |
| 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(&fi->lock); |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| spin_unlock(&fi->lock); |
| } |
| |
| io->iocb->ki_complete(io->iocb, res, 0); |
| } |
| |
| kref_put(&io->refcnt, fuse_io_release); |
| } |
| |
| static struct fuse_io_args *fuse_io_alloc(struct fuse_io_priv *io, |
| unsigned int npages) |
| { |
| struct fuse_io_args *ia; |
| |
| ia = kzalloc(sizeof(*ia), GFP_KERNEL); |
| if (ia) { |
| ia->io = io; |
| ia->ap.pages = fuse_pages_alloc(npages, GFP_KERNEL, |
| &ia->ap.descs); |
| if (!ia->ap.pages) { |
| kfree(ia); |
| ia = NULL; |
| } |
| } |
| return ia; |
| } |
| |
| static void fuse_io_free(struct fuse_io_args *ia) |
| { |
| kfree(ia->ap.pages); |
| kfree(ia); |
| } |
| |
| static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_args *args, |
| int err) |
| { |
| struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args); |
| struct fuse_io_priv *io = ia->io; |
| ssize_t pos = -1; |
| |
| fuse_release_user_pages(&ia->ap, io->should_dirty); |
| |
| if (err) { |
| /* Nothing */ |
| } else if (io->write) { |
| if (ia->write.out.size > ia->write.in.size) { |
| err = -EIO; |
| } else if (ia->write.in.size != ia->write.out.size) { |
| pos = ia->write.in.offset - io->offset + |
| ia->write.out.size; |
| } |
| } else { |
| u32 outsize = args->out_args[0].size; |
| |
| if (ia->read.in.size != outsize) |
| pos = ia->read.in.offset - io->offset + outsize; |
| } |
| |
| fuse_aio_complete(io, err, pos); |
| fuse_io_free(ia); |
| } |
| |
| static ssize_t fuse_async_req_send(struct fuse_conn *fc, |
| struct fuse_io_args *ia, size_t num_bytes) |
| { |
| ssize_t err; |
| struct fuse_io_priv *io = ia->io; |
| |
| spin_lock(&io->lock); |
| kref_get(&io->refcnt); |
| io->size += num_bytes; |
| io->reqs++; |
| spin_unlock(&io->lock); |
| |
| ia->ap.args.end = fuse_aio_complete_req; |
| ia->ap.args.may_block = io->should_dirty; |
| err = fuse_simple_background(fc, &ia->ap.args, GFP_KERNEL); |
| if (err) |
| fuse_aio_complete_req(fc, &ia->ap.args, err); |
| |
| return num_bytes; |
| } |
| |
| static ssize_t fuse_send_read(struct fuse_io_args *ia, loff_t pos, size_t count, |
| fl_owner_t owner) |
| { |
| struct file *file = ia->io->iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| |
| fuse_read_args_fill(ia, file, pos, count, FUSE_READ); |
| if (owner != NULL) { |
| ia->read.in.read_flags |= FUSE_READ_LOCKOWNER; |
| ia->read.in.lock_owner = fuse_lock_owner_id(fc, owner); |
| } |
| |
| if (ia->io->async) |
| return fuse_async_req_send(fc, ia, count); |
| |
| return fuse_simple_request(fc, &ia->ap.args); |
| } |
| |
| 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(&fi->lock); |
| if (attr_ver == fi->attr_version && size < inode->i_size && |
| !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| i_size_write(inode, size); |
| } |
| spin_unlock(&fi->lock); |
| } |
| |
| static void fuse_short_read(struct inode *inode, u64 attr_ver, size_t num_read, |
| struct fuse_args_pages *ap) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (fc->writeback_cache) { |
| /* |
| * A hole in a file. Some data after the hole are in page cache, |
| * but have not reached the client fs yet. So, the hole is not |
| * present there. |
| */ |
| int i; |
| int start_idx = num_read >> PAGE_SHIFT; |
| size_t off = num_read & (PAGE_SIZE - 1); |
| |
| for (i = start_idx; i < ap->num_pages; i++) { |
| zero_user_segment(ap->pages[i], off, PAGE_SIZE); |
| off = 0; |
| } |
| } else { |
| loff_t pos = page_offset(ap->pages[0]) + num_read; |
| fuse_read_update_size(inode, pos, attr_ver); |
| } |
| } |
| |
| static int fuse_do_readpage(struct file *file, struct page *page) |
| { |
| struct inode *inode = page->mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| loff_t pos = page_offset(page); |
| struct fuse_page_desc desc = { .length = PAGE_SIZE }; |
| struct fuse_io_args ia = { |
| .ap.args.page_zeroing = true, |
| .ap.args.out_pages = true, |
| .ap.num_pages = 1, |
| .ap.pages = &page, |
| .ap.descs = &desc, |
| }; |
| ssize_t res; |
| u64 attr_ver; |
| |
| /* |
| * 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); |
| |
| attr_ver = fuse_get_attr_version(fc); |
| |
| /* Don't overflow end offset */ |
| if (pos + (desc.length - 1) == LLONG_MAX) |
| desc.length--; |
| |
| fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ); |
| res = fuse_simple_request(fc, &ia.ap.args); |
| if (res < 0) |
| return res; |
| /* |
| * Short read means EOF. If file size is larger, truncate it |
| */ |
| if (res < desc.length) |
| fuse_short_read(inode, attr_ver, res, &ia.ap); |
| |
| SetPageUptodate(page); |
| |
| return 0; |
| } |
| |
| static int fuse_readpage(struct file *file, struct page *page) |
| { |
| struct inode *inode = page->mapping->host; |
| int err; |
| |
| err = -EIO; |
| if (is_bad_inode(inode)) |
| goto out; |
| |
| err = fuse_do_readpage(file, page); |
| fuse_invalidate_atime(inode); |
| out: |
| unlock_page(page); |
| return err; |
| } |
| |
| static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_args *args, |
| int err) |
| { |
| int i; |
| struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args); |
| struct fuse_args_pages *ap = &ia->ap; |
| size_t count = ia->read.in.size; |
| size_t num_read = args->out_args[0].size; |
| struct address_space *mapping = NULL; |
| |
| for (i = 0; mapping == NULL && i < ap->num_pages; i++) |
| mapping = ap->pages[i]->mapping; |
| |
| if (mapping) { |
| struct inode *inode = mapping->host; |
| |
| /* |
| * Short read means EOF. If file size is larger, truncate it |
| */ |
| if (!err && num_read < count) |
| fuse_short_read(inode, ia->read.attr_ver, num_read, ap); |
| |
| fuse_invalidate_atime(inode); |
| } |
| |
| for (i = 0; i < ap->num_pages; i++) { |
| struct page *page = ap->pages[i]; |
| |
| if (!err) |
| SetPageUptodate(page); |
| else |
| SetPageError(page); |
| unlock_page(page); |
| put_page(page); |
| } |
| if (ia->ff) |
| fuse_file_put(ia->ff, false, false); |
| |
| fuse_io_free(ia); |
| } |
| |
| static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file) |
| { |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_args_pages *ap = &ia->ap; |
| loff_t pos = page_offset(ap->pages[0]); |
| size_t count = ap->num_pages << PAGE_SHIFT; |
| ssize_t res; |
| int err; |
| |
| ap->args.out_pages = true; |
| ap->args.page_zeroing = true; |
| ap->args.page_replace = true; |
| |
| /* Don't overflow end offset */ |
| if (pos + (count - 1) == LLONG_MAX) { |
| count--; |
| ap->descs[ap->num_pages - 1].length--; |
| } |
| WARN_ON((loff_t) (pos + count) < 0); |
| |
| fuse_read_args_fill(ia, file, pos, count, FUSE_READ); |
| ia->read.attr_ver = fuse_get_attr_version(fc); |
| if (fc->async_read) { |
| ia->ff = fuse_file_get(ff); |
| ap->args.end = fuse_readpages_end; |
| err = fuse_simple_background(fc, &ap->args, GFP_KERNEL); |
| if (!err) |
| return; |
| } else { |
| res = fuse_simple_request(fc, &ap->args); |
| err = res < 0 ? res : 0; |
| } |
| fuse_readpages_end(fc, &ap->args, err); |
| } |
| |
| static void fuse_readahead(struct readahead_control *rac) |
| { |
| struct inode *inode = rac->mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| unsigned int i, max_pages, nr_pages = 0; |
| |
| if (is_bad_inode(inode)) |
| return; |
| |
| max_pages = min_t(unsigned int, fc->max_pages, |
| fc->max_read / PAGE_SIZE); |
| |
| for (;;) { |
| struct fuse_io_args *ia; |
| struct fuse_args_pages *ap; |
| |
| nr_pages = readahead_count(rac) - nr_pages; |
| if (nr_pages > max_pages) |
| nr_pages = max_pages; |
| if (nr_pages == 0) |
| break; |
| ia = fuse_io_alloc(NULL, nr_pages); |
| if (!ia) |
| return; |
| ap = &ia->ap; |
| nr_pages = __readahead_batch(rac, ap->pages, nr_pages); |
| for (i = 0; i < nr_pages; i++) { |
| fuse_wait_on_page_writeback(inode, |
| readahead_index(rac) + i); |
| ap->descs[i].length = PAGE_SIZE; |
| } |
| ap->num_pages = nr_pages; |
| fuse_send_readpages(ia, rac->file); |
| } |
| } |
| |
| static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to) |
| { |
| 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 || |
| (iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) { |
| int err; |
| err = fuse_update_attributes(inode, iocb->ki_filp); |
| if (err) |
| return err; |
| } |
| |
| return generic_file_read_iter(iocb, to); |
| } |
| |
| static void fuse_write_args_fill(struct fuse_io_args *ia, struct fuse_file *ff, |
| loff_t pos, size_t count) |
| { |
| struct fuse_args *args = &ia->ap.args; |
| |
| ia->write.in.fh = ff->fh; |
| ia->write.in.offset = pos; |
| ia->write.in.size = count; |
| args->opcode = FUSE_WRITE; |
| args->nodeid = ff->nodeid; |
| args->in_numargs = 2; |
| if (ff->fc->minor < 9) |
| args->in_args[0].size = FUSE_COMPAT_WRITE_IN_SIZE; |
| else |
| args->in_args[0].size = sizeof(ia->write.in); |
| args->in_args[0].value = &ia->write.in; |
| args->in_args[1].size = count; |
| args->out_numargs = 1; |
| args->out_args[0].size = sizeof(ia->write.out); |
| args->out_args[0].value = &ia->write.out; |
| } |
| |
| static unsigned int fuse_write_flags(struct kiocb *iocb) |
| { |
| unsigned int flags = iocb->ki_filp->f_flags; |
| |
| if (iocb->ki_flags & IOCB_DSYNC) |
| flags |= O_DSYNC; |
| if (iocb->ki_flags & IOCB_SYNC) |
| flags |= O_SYNC; |
| |
| return flags; |
| } |
| |
| static ssize_t fuse_send_write(struct fuse_io_args *ia, loff_t pos, |
| size_t count, fl_owner_t owner) |
| { |
| struct kiocb *iocb = ia->io->iocb; |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| struct fuse_write_in *inarg = &ia->write.in; |
| ssize_t err; |
| |
| fuse_write_args_fill(ia, ff, pos, count); |
| inarg->flags = fuse_write_flags(iocb); |
| if (owner != NULL) { |
| inarg->write_flags |= FUSE_WRITE_LOCKOWNER; |
| inarg->lock_owner = fuse_lock_owner_id(fc, owner); |
| } |
| |
| if (ia->io->async) |
| return fuse_async_req_send(fc, ia, count); |
| |
| err = fuse_simple_request(fc, &ia->ap.args); |
| if (!err && ia->write.out.size > count) |
| err = -EIO; |
| |
| return err ?: ia->write.out.size; |
| } |
| |
| bool 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); |
| bool ret = false; |
| |
| spin_lock(&fi->lock); |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| if (pos > inode->i_size) { |
| i_size_write(inode, pos); |
| ret = true; |
| } |
| spin_unlock(&fi->lock); |
| |
| return ret; |
| } |
| |
| static ssize_t fuse_send_write_pages(struct fuse_io_args *ia, |
| struct kiocb *iocb, struct inode *inode, |
| loff_t pos, size_t count) |
| { |
| struct fuse_args_pages *ap = &ia->ap; |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| struct fuse_conn *fc = ff->fc; |
| unsigned int offset, i; |
| int err; |
| |
| for (i = 0; i < ap->num_pages; i++) |
| fuse_wait_on_page_writeback(inode, ap->pages[i]->index); |
| |
| fuse_write_args_fill(ia, ff, pos, count); |
| ia->write.in.flags = fuse_write_flags(iocb); |
| |
| err = fuse_simple_request(fc, &ap->args); |
| if (!err && ia->write.out.size > count) |
| err = -EIO; |
| |
| offset = ap->descs[0].offset; |
| count = ia->write.out.size; |
| for (i = 0; i < ap->num_pages; i++) { |
| struct page *page = ap->pages[i]; |
| |
| if (!err && !offset && count >= PAGE_SIZE) |
| SetPageUptodate(page); |
| |
| if (count > PAGE_SIZE - offset) |
| count -= PAGE_SIZE - offset; |
| else |
| count = 0; |
| offset = 0; |
| |
| unlock_page(page); |
| put_page(page); |
| } |
| |
| return err; |
| } |
| |
| static ssize_t fuse_fill_write_pages(struct fuse_args_pages *ap, |
| struct address_space *mapping, |
| struct iov_iter *ii, loff_t pos, |
| unsigned int max_pages) |
| { |
| struct fuse_conn *fc = get_fuse_conn(mapping->host); |
| unsigned offset = pos & (PAGE_SIZE - 1); |
| size_t count = 0; |
| int err; |
| |
| ap->args.in_pages = true; |
| ap->descs[0].offset = offset; |
| |
| do { |
| size_t tmp; |
| struct page *page; |
| pgoff_t index = pos >> PAGE_SHIFT; |
| size_t bytes = min_t(size_t, PAGE_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); |
| |
| tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); |
| flush_dcache_page(page); |
| |
| iov_iter_advance(ii, tmp); |
| if (!tmp) { |
| unlock_page(page); |
| put_page(page); |
| bytes = min(bytes, iov_iter_single_seg_count(ii)); |
| goto again; |
| } |
| |
| err = 0; |
| ap->pages[ap->num_pages] = page; |
| ap->descs[ap->num_pages].length = tmp; |
| ap->num_pages++; |
| |
| count += tmp; |
| pos += tmp; |
| offset += tmp; |
| if (offset == PAGE_SIZE) |
| offset = 0; |
| |
| if (!fc->big_writes) |
| break; |
| } while (iov_iter_count(ii) && count < fc->max_write && |
| ap->num_pages < max_pages && offset == 0); |
| |
| return count > 0 ? count : err; |
| } |
| |
| static inline unsigned int fuse_wr_pages(loff_t pos, size_t len, |
| unsigned int max_pages) |
| { |
| return min_t(unsigned int, |
| ((pos + len - 1) >> PAGE_SHIFT) - |
| (pos >> PAGE_SHIFT) + 1, |
| max_pages); |
| } |
| |
| static ssize_t fuse_perform_write(struct kiocb *iocb, |
| 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 (inode->i_size < pos + iov_iter_count(ii)) |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| |
| do { |
| ssize_t count; |
| struct fuse_io_args ia = {}; |
| struct fuse_args_pages *ap = &ia.ap; |
| unsigned int nr_pages = fuse_wr_pages(pos, iov_iter_count(ii), |
| fc->max_pages); |
| |
| ap->pages = fuse_pages_alloc(nr_pages, GFP_KERNEL, &ap->descs); |
| if (!ap->pages) { |
| err = -ENOMEM; |
| break; |
| } |
| |
| count = fuse_fill_write_pages(ap, mapping, ii, pos, nr_pages); |
| if (count <= 0) { |
| err = count; |
| } else { |
| err = fuse_send_write_pages(&ia, iocb, inode, |
| pos, count); |
| if (!err) { |
| size_t num_written = ia.write.out.size; |
| |
| res += num_written; |
| pos += num_written; |
| |
| /* break out of the loop on short write */ |
| if (num_written != count) |
| err = -EIO; |
| } |
| } |
| kfree(ap->pages); |
| } 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_cache_write_iter(struct kiocb *iocb, struct iov_iter *from) |
| { |
| struct file *file = iocb->ki_filp; |
| struct address_space *mapping = file->f_mapping; |
| ssize_t written = 0; |
| ssize_t written_buffered = 0; |
| struct inode *inode = mapping->host; |
| ssize_t err; |
| loff_t endbyte = 0; |
| |
| if (get_fuse_conn(inode)->writeback_cache) { |
| /* Update size (EOF optimization) and mode (SUID clearing) */ |
| err = fuse_update_attributes(mapping->host, file); |
| if (err) |
| return err; |
| |
| return generic_file_write_iter(iocb, from); |
| } |
| |
| inode_lock(inode); |
| |
| /* We can write back this queue in page reclaim */ |
| current->backing_dev_info = inode_to_bdi(inode); |
| |
| err = generic_write_checks(iocb, from); |
| if (err <= 0) |
| goto out; |
| |
| err = file_remove_privs(file); |
| if (err) |
| goto out; |
| |
| err = file_update_time(file); |
| if (err) |
| goto out; |
| |
| if (iocb->ki_flags & IOCB_DIRECT) { |
| loff_t pos = iocb->ki_pos; |
| written = generic_file_direct_write(iocb, from); |
| if (written < 0 || !iov_iter_count(from)) |
| goto out; |
| |
| pos += written; |
| |
| written_buffered = fuse_perform_write(iocb, mapping, from, 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_SHIFT, |
| endbyte >> PAGE_SHIFT); |
| |
| written += written_buffered; |
| iocb->ki_pos = pos + written_buffered; |
| } else { |
| written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos); |
| if (written >= 0) |
| iocb->ki_pos += written; |
| } |
| out: |
| current->backing_dev_info = NULL; |
| inode_unlock(inode); |
| if (written > 0) |
| written = generic_write_sync(iocb, written); |
| |
| return written ? written : err; |
| } |
| |
| static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs, |
| unsigned int index, |
| unsigned int nr_pages) |
| { |
| int i; |
| |
| for (i = index; i < index + nr_pages; i++) |
| descs[i].length = PAGE_SIZE - 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_args_pages *ap, struct iov_iter *ii, |
| size_t *nbytesp, int write, |
| unsigned int max_pages) |
| { |
| size_t nbytes = 0; /* # bytes already packed in req */ |
| ssize_t ret = 0; |
| |
| /* Special case for kernel I/O: can copy directly into the buffer */ |
| if (iov_iter_is_kvec(ii)) { |
| unsigned long user_addr = fuse_get_user_addr(ii); |
| size_t frag_size = fuse_get_frag_size(ii, *nbytesp); |
| |
| if (write) |
| ap->args.in_args[1].value = (void *) user_addr; |
| else |
| ap->args.out_args[0].value = (void *) user_addr; |
| |
| iov_iter_advance(ii, frag_size); |
| *nbytesp = frag_size; |
| return 0; |
| } |
| |
| while (nbytes < *nbytesp && ap->num_pages < max_pages) { |
| unsigned npages; |
| size_t start; |
| ret = iov_iter_get_pages(ii, &ap->pages[ap->num_pages], |
| *nbytesp - nbytes, |
| max_pages - ap->num_pages, |
| &start); |
| if (ret < 0) |
| break; |
| |
| iov_iter_advance(ii, ret); |
| nbytes += ret; |
| |
| ret += start; |
| npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE; |
| |
| ap->descs[ap->num_pages].offset = start; |
| fuse_page_descs_length_init(ap->descs, ap->num_pages, npages); |
| |
| ap->num_pages += npages; |
| ap->descs[ap->num_pages - 1].length -= |
| (PAGE_SIZE - ret) & (PAGE_SIZE - 1); |
| } |
| |
| if (write) |
| ap->args.in_pages = true; |
| else |
| ap->args.out_pages = true; |
| |
| *nbytesp = nbytes; |
| |
| return ret < 0 ? ret : 0; |
| } |
| |
| ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, |
| loff_t *ppos, int flags) |
| { |
| int write = flags & FUSE_DIO_WRITE; |
| int cuse = flags & FUSE_DIO_CUSE; |
| struct file *file = io->iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| 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; |
| size_t count = iov_iter_count(iter); |
| pgoff_t idx_from = pos >> PAGE_SHIFT; |
| pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT; |
| ssize_t res = 0; |
| int err = 0; |
| struct fuse_io_args *ia; |
| unsigned int max_pages; |
| |
| max_pages = iov_iter_npages(iter, fc->max_pages); |
| ia = fuse_io_alloc(io, max_pages); |
| if (!ia) |
| return -ENOMEM; |
| |
| ia->io = io; |
| if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) { |
| if (!write) |
| inode_lock(inode); |
| fuse_sync_writes(inode); |
| if (!write) |
| inode_unlock(inode); |
| } |
| |
| io->should_dirty = !write && iter_is_iovec(iter); |
| while (count) { |
| ssize_t nres; |
| fl_owner_t owner = current->files; |
| size_t nbytes = min(count, nmax); |
| |
| err = fuse_get_user_pages(&ia->ap, iter, &nbytes, write, |
| max_pages); |
| if (err && !nbytes) |
| break; |
| |
| if (write) { |
| if (!capable(CAP_FSETID)) |
| ia->write.in.write_flags |= FUSE_WRITE_KILL_PRIV; |
| |
| nres = fuse_send_write(ia, pos, nbytes, owner); |
| } else { |
| nres = fuse_send_read(ia, pos, nbytes, owner); |
| } |
| |
| if (!io->async || nres < 0) { |
| fuse_release_user_pages(&ia->ap, io->should_dirty); |
| fuse_io_free(ia); |
| } |
| ia = NULL; |
| if (nres < 0) { |
| iov_iter_revert(iter, nbytes); |
| err = nres; |
| break; |
| } |
| WARN_ON(nres > nbytes); |
| |
| count -= nres; |
| res += nres; |
| pos += nres; |
| if (nres != nbytes) { |
| iov_iter_revert(iter, nbytes - nres); |
| break; |
| } |
| if (count) { |
| max_pages = iov_iter_npages(iter, fc->max_pages); |
| ia = fuse_io_alloc(io, max_pages); |
| if (!ia) |
| break; |
| } |
| } |
| if (ia) |
| fuse_io_free(ia); |
| if (res > 0) |
| *ppos = pos; |
| |
| return res > 0 ? res : err; |
| } |
| EXPORT_SYMBOL_GPL(fuse_direct_io); |
| |
| static ssize_t __fuse_direct_read(struct fuse_io_priv *io, |
| struct iov_iter *iter, |
| loff_t *ppos) |
| { |
| ssize_t res; |
| struct inode *inode = file_inode(io->iocb->ki_filp); |
| |
| res = fuse_direct_io(io, iter, ppos, 0); |
| |
| fuse_invalidate_atime(inode); |
| |
| return res; |
| } |
| |
| static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter); |
| |
| static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to) |
| { |
| ssize_t res; |
| |
| if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) { |
| res = fuse_direct_IO(iocb, to); |
| } else { |
| struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb); |
| |
| res = __fuse_direct_read(&io, to, &iocb->ki_pos); |
| } |
| |
| return res; |
| } |
| |
| static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) |
| { |
| struct inode *inode = file_inode(iocb->ki_filp); |
| struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb); |
| ssize_t res; |
| |
| /* Don't allow parallel writes to the same file */ |
| inode_lock(inode); |
| res = generic_write_checks(iocb, from); |
| if (res > 0) { |
| if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) { |
| res = fuse_direct_IO(iocb, from); |
| } else { |
| res = fuse_direct_io(&io, from, &iocb->ki_pos, |
| FUSE_DIO_WRITE); |
| } |
| } |
| fuse_invalidate_attr(inode); |
| if (res > 0) |
| fuse_write_update_size(inode, iocb->ki_pos); |
| inode_unlock(inode); |
| |
| return res; |
| } |
| |
| static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
| { |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| |
| if (is_bad_inode(file_inode(file))) |
| return -EIO; |
| |
| if (!(ff->open_flags & FOPEN_DIRECT_IO)) |
| return fuse_cache_read_iter(iocb, to); |
| else |
| return fuse_direct_read_iter(iocb, to); |
| } |
| |
| static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
| { |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| |
| if (is_bad_inode(file_inode(file))) |
| return -EIO; |
| |
| if (!(ff->open_flags & FOPEN_DIRECT_IO)) |
| return fuse_cache_write_iter(iocb, from); |
| else |
| return fuse_direct_write_iter(iocb, from); |
| } |
| |
| static void fuse_writepage_free(struct fuse_writepage_args *wpa) |
| { |
| struct fuse_args_pages *ap = &wpa->ia.ap; |
| int i; |
| |
| for (i = 0; i < ap->num_pages; i++) |
| __free_page(ap->pages[i]); |
| |
| if (wpa->ia.ff) |
| fuse_file_put(wpa->ia.ff, false, false); |
| |
| kfree(ap->pages); |
| kfree(wpa); |
| } |
| |
| static void fuse_writepage_finish(struct fuse_conn *fc, |
| struct fuse_writepage_args *wpa) |
| { |
| struct fuse_args_pages *ap = &wpa->ia.ap; |
| struct inode *inode = wpa->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct backing_dev_info *bdi = inode_to_bdi(inode); |
| int i; |
| |
| for (i = 0; i < ap->num_pages; i++) { |
| dec_wb_stat(&bdi->wb, WB_WRITEBACK); |
| dec_node_page_state(ap->pages[i], NR_WRITEBACK_TEMP); |
| wb_writeout_inc(&bdi->wb); |
| } |
| wake_up(&fi->page_waitq); |
| } |
| |
| /* Called under fi->lock, may release and reacquire it */ |
| static void fuse_send_writepage(struct fuse_conn *fc, |
| struct fuse_writepage_args *wpa, loff_t size) |
| __releases(fi->lock) |
| __acquires(fi->lock) |
| { |
| struct fuse_writepage_args *aux, *next; |
| struct fuse_inode *fi = get_fuse_inode(wpa->inode); |
| struct fuse_write_in *inarg = &wpa->ia.write.in; |
| struct fuse_args *args = &wpa->ia.ap.args; |
| __u64 data_size = wpa->ia.ap.num_pages * PAGE_SIZE; |
| int err; |
| |
| fi->writectr++; |
| 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; |
| } |
| |
| args->in_args[1].size = inarg->size; |
| args->force = true; |
| args->nocreds = true; |
| |
| err = fuse_simple_background(fc, args, GFP_ATOMIC); |
| if (err == -ENOMEM) { |
| spin_unlock(&fi->lock); |
| err = fuse_simple_background(fc, args, GFP_NOFS | __GFP_NOFAIL); |
| spin_lock(&fi->lock); |
| } |
| |
| /* Fails on broken connection only */ |
| if (unlikely(err)) |
| goto out_free; |
| |
| return; |
| |
| out_free: |
| fi->writectr--; |
| rb_erase(&wpa->writepages_entry, &fi->writepages); |
| fuse_writepage_finish(fc, wpa); |
| spin_unlock(&fi->lock); |
| |
| /* After fuse_writepage_finish() aux request list is private */ |
| for (aux = wpa->next; aux; aux = next) { |
| next = aux->next; |
| aux->next = NULL; |
| fuse_writepage_free(aux); |
| } |
| |
| fuse_writepage_free(wpa); |
| spin_lock(&fi->lock); |
| } |
| |
| /* |
| * If fi->writectr is positive (no truncate or fsync going on) send |
| * all queued writepage requests. |
| * |
| * Called with fi->lock |
| */ |
| void fuse_flush_writepages(struct inode *inode) |
| __releases(fi->lock) |
| __acquires(fi->lock) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| loff_t crop = i_size_read(inode); |
| struct fuse_writepage_args *wpa; |
| |
| while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) { |
| wpa = list_entry(fi->queued_writes.next, |
| struct fuse_writepage_args, queue_entry); |
| list_del_init(&wpa->queue_entry); |
| fuse_send_writepage(fc, wpa, crop); |
| } |
| } |
| |
| static struct fuse_writepage_args *fuse_insert_writeback(struct rb_root *root, |
| struct fuse_writepage_args *wpa) |
| { |
| pgoff_t idx_from = wpa->ia.write.in.offset >> PAGE_SHIFT; |
| pgoff_t idx_to = idx_from + wpa->ia.ap.num_pages - 1; |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| |
| WARN_ON(!wpa->ia.ap.num_pages); |
| while (*p) { |
| struct fuse_writepage_args *curr; |
| pgoff_t curr_index; |
| |
| parent = *p; |
| curr = rb_entry(parent, struct fuse_writepage_args, |
| writepages_entry); |
| WARN_ON(curr->inode != wpa->inode); |
| curr_index = curr->ia.write.in.offset >> PAGE_SHIFT; |
| |
| if (idx_from >= curr_index + curr->ia.ap.num_pages) |
| p = &(*p)->rb_right; |
| else if (idx_to < curr_index) |
| p = &(*p)->rb_left; |
| else |
| return curr; |
| } |
| |
| rb_link_node(&wpa->writepages_entry, parent, p); |
| rb_insert_color(&wpa->writepages_entry, root); |
| return NULL; |
| } |
| |
| static void tree_insert(struct rb_root *root, struct fuse_writepage_args *wpa) |
| { |
| WARN_ON(fuse_insert_writeback(root, wpa)); |
| } |
| |
| static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_args *args, |
| int error) |
| { |
| struct fuse_writepage_args *wpa = |
| container_of(args, typeof(*wpa), ia.ap.args); |
| struct inode *inode = wpa->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| mapping_set_error(inode->i_mapping, error); |
| spin_lock(&fi->lock); |
| rb_erase(&wpa->writepages_entry, &fi->writepages); |
| while (wpa->next) { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_write_in *inarg = &wpa->ia.write.in; |
| struct fuse_writepage_args *next = wpa->next; |
| |
| wpa->next = next->next; |
| next->next = NULL; |
| next->ia.ff = fuse_file_get(wpa->ia.ff); |
| tree_insert(&fi->writepages, next); |
| |
| /* |
| * Skip fuse_flush_writepages() to make it easy to crop requests |
| * based on primary request size. |
| * |
| * 1st case (trivial): there are no concurrent activities using |
| * fuse_set/release_nowrite. Then we're on safe side because |
| * fuse_flush_writepages() would call fuse_send_writepage() |
| * anyway. |
| * |
| * 2nd case: someone called fuse_set_nowrite and it is waiting |
| * now for completion of all in-flight requests. This happens |
| * rarely and no more than once per page, so this should be |
| * okay. |
| * |
| * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle |
| * of fuse_set_nowrite..fuse_release_nowrite section. The fact |
| * that fuse_set_nowrite returned implies that all in-flight |
| * requests were completed along with all of their secondary |
| * requests. Further primary requests are blocked by negative |
| * writectr. Hence there cannot be any in-flight requests and |
| * no invocations of fuse_writepage_end() while we're in |
| * fuse_set_nowrite..fuse_release_nowrite section. |
| */ |
| fuse_send_writepage(fc, next, inarg->offset + inarg->size); |
| } |
| fi->writectr--; |
| fuse_writepage_finish(fc, wpa); |
| spin_unlock(&fi->lock); |
| fuse_writepage_free(wpa); |
| } |
| |
| static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc, |
| struct fuse_inode *fi) |
| { |
| struct fuse_file *ff = NULL; |
| |
| spin_lock(&fi->lock); |
| if (!list_empty(&fi->write_files)) { |
| ff = list_entry(fi->write_files.next, struct fuse_file, |
| write_entry); |
| fuse_file_get(ff); |
| } |
| spin_unlock(&fi->lock); |
| |
| return ff; |
| } |
| |
| static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc, |
| struct fuse_inode *fi) |
| { |
| struct fuse_file *ff = __fuse_write_file_get(fc, fi); |
| WARN_ON(!ff); |
| return ff; |
| } |
| |
| int fuse_write_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_file *ff; |
| int err; |
| |
| ff = __fuse_write_file_get(fc, fi); |
| err = fuse_flush_times(inode, ff); |
| if (ff) |
| fuse_file_put(ff, false, false); |
| |
| return err; |
| } |
| |
| static struct fuse_writepage_args *fuse_writepage_args_alloc(void) |
| { |
| struct fuse_writepage_args *wpa; |
| struct fuse_args_pages *ap; |
| |
| wpa = kzalloc(sizeof(*wpa), GFP_NOFS); |
| if (wpa) { |
| ap = &wpa->ia.ap; |
| ap->num_pages = 0; |
| ap->pages = fuse_pages_alloc(1, GFP_NOFS, &ap->descs); |
| if (!ap->pages) { |
| kfree(wpa); |
| wpa = NULL; |
| } |
| } |
| return wpa; |
| |
| } |
| |
| 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_writepage_args *wpa; |
| struct fuse_args_pages *ap; |
| struct page *tmp_page; |
| int error = -ENOMEM; |
| |
| set_page_writeback(page); |
| |
| wpa = fuse_writepage_args_alloc(); |
| if (!wpa) |
| goto err; |
| ap = &wpa->ia.ap; |
| |
| tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
| if (!tmp_page) |
| goto err_free; |
| |
| error = -EIO; |
| wpa->ia.ff = fuse_write_file_get(fc, fi); |
| if (!wpa->ia.ff) |
| goto err_nofile; |
| |
| fuse_write_args_fill(&wpa->ia, wpa->ia.ff, page_offset(page), 0); |
| |
| copy_highpage(tmp_page, page); |
| wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE; |
| wpa->next = NULL; |
| ap->args.in_pages = true; |
| ap->num_pages = 1; |
| ap->pages[0] = tmp_page; |
| ap->descs[0].offset = 0; |
| ap->descs[0].length = PAGE_SIZE; |
| ap->args.end = fuse_writepage_end; |
| wpa->inode = inode; |
| |
| inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK); |
| inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP); |
| |
| spin_lock(&fi->lock); |
| tree_insert(&fi->writepages, wpa); |
| list_add_tail(&wpa->queue_entry, &fi->queued_writes); |
| fuse_flush_writepages(inode); |
| spin_unlock(&fi->lock); |
| |
| end_page_writeback(page); |
| |
| return 0; |
| |
| err_nofile: |
| __free_page(tmp_page); |
| err_free: |
| kfree(wpa); |
| err: |
| mapping_set_error(page->mapping, error); |
| 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); |
| unlock_page(page); |
| return 0; |
| } |
| |
| err = fuse_writepage_locked(page); |
| unlock_page(page); |
| |
| return err; |
| } |
| |
| struct fuse_fill_wb_data { |
| struct fuse_writepage_args *wpa; |
| struct fuse_file *ff; |
| struct inode *inode; |
| struct page **orig_pages; |
| unsigned int max_pages; |
| }; |
| |
| static bool fuse_pages_realloc(struct fuse_fill_wb_data *data) |
| { |
| struct fuse_args_pages *ap = &data->wpa->ia.ap; |
| struct fuse_conn *fc = get_fuse_conn(data->inode); |
| struct page **pages; |
| struct fuse_page_desc *descs; |
| unsigned int npages = min_t(unsigned int, |
| max_t(unsigned int, data->max_pages * 2, |
| FUSE_DEFAULT_MAX_PAGES_PER_REQ), |
| fc->max_pages); |
| WARN_ON(npages <= data->max_pages); |
| |
| pages = fuse_pages_alloc(npages, GFP_NOFS, &descs); |
| if (!pages) |
| return false; |
| |
| memcpy(pages, ap->pages, sizeof(struct page *) * ap->num_pages); |
| memcpy(descs, ap->descs, sizeof(struct fuse_page_desc) * ap->num_pages); |
| kfree(ap->pages); |
| ap->pages = pages; |
| ap->descs = descs; |
| data->max_pages = npages; |
| |
| return true; |
| } |
| |
| static void fuse_writepages_send(struct fuse_fill_wb_data *data) |
| { |
| struct fuse_writepage_args *wpa = data->wpa; |
| struct inode *inode = data->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| int num_pages = wpa->ia.ap.num_pages; |
| int i; |
| |
| wpa->ia.ff = fuse_file_get(data->ff); |
| spin_lock(&fi->lock); |
| list_add_tail(&wpa->queue_entry, &fi->queued_writes); |
| fuse_flush_writepages(inode); |
| spin_unlock(&fi->lock); |
| |
| for (i = 0; i < num_pages; i++) |
| end_page_writeback(data->orig_pages[i]); |
| } |
| |
| /* |
| * Check under fi->lock if the page is under writeback, and insert it onto the |
| * rb_tree if not. Otherwise iterate auxiliary write requests, to see if there's |
| * one already added for a page at this offset. If there's none, then insert |
| * this new request onto the auxiliary list, otherwise reuse the existing one by |
| * swapping the new temp page with the old one. |
| */ |
| static bool fuse_writepage_add(struct fuse_writepage_args *new_wpa, |
| struct page *page) |
| { |
| struct fuse_inode *fi = get_fuse_inode(new_wpa->inode); |
| struct fuse_writepage_args *tmp; |
| struct fuse_writepage_args *old_wpa; |
| struct fuse_args_pages *new_ap = &new_wpa->ia.ap; |
| |
| WARN_ON(new_ap->num_pages != 0); |
| new_ap->num_pages = 1; |
| |
| spin_lock(&fi->lock); |
| old_wpa = fuse_insert_writeback(&fi->writepages, new_wpa); |
| if (!old_wpa) { |
| spin_unlock(&fi->lock); |
| return true; |
| } |
| |
| for (tmp = old_wpa->next; tmp; tmp = tmp->next) { |
| pgoff_t curr_index; |
| |
| WARN_ON(tmp->inode != new_wpa->inode); |
| curr_index = tmp->ia.write.in.offset >> PAGE_SHIFT; |
| if (curr_index == page->index) { |
| WARN_ON(tmp->ia.ap.num_pages != 1); |
| swap(tmp->ia.ap.pages[0], new_ap->pages[0]); |
| break; |
| } |
| } |
| |
| if (!tmp) { |
| new_wpa->next = old_wpa->next; |
| old_wpa->next = new_wpa; |
| } |
| |
| spin_unlock(&fi->lock); |
| |
| if (tmp) { |
| struct backing_dev_info *bdi = inode_to_bdi(new_wpa->inode); |
| |
| dec_wb_stat(&bdi->wb, WB_WRITEBACK); |
| dec_node_page_state(new_ap->pages[0], NR_WRITEBACK_TEMP); |
| wb_writeout_inc(&bdi->wb); |
| fuse_writepage_free(new_wpa); |
| } |
| |
| return false; |
| } |
| |
| static bool fuse_writepage_need_send(struct fuse_conn *fc, struct page *page, |
| struct fuse_args_pages *ap, |
| struct fuse_fill_wb_data *data) |
| { |
| WARN_ON(!ap->num_pages); |
| |
| /* |
| * 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. |
| */ |
| if (fuse_page_is_writeback(data->inode, page->index)) |
| return true; |
| |
| /* Reached max pages */ |
| if (ap->num_pages == fc->max_pages) |
| return true; |
| |
| /* Reached max write bytes */ |
| if ((ap->num_pages + 1) * PAGE_SIZE > fc->max_write) |
| return true; |
| |
| /* Discontinuity */ |
| if (data->orig_pages[ap->num_pages - 1]->index + 1 != page->index) |
| return true; |
| |
| /* Need to grow the pages array? If so, did the expansion fail? */ |
| if (ap->num_pages == data->max_pages && !fuse_pages_realloc(data)) |
| return true; |
| |
| return false; |
| } |
| |
| static int fuse_writepages_fill(struct page *page, |
| struct writeback_control *wbc, void *_data) |
| { |
| struct fuse_fill_wb_data *data = _data; |
| struct fuse_writepage_args *wpa = data->wpa; |
| struct fuse_args_pages *ap = &wpa->ia.ap; |
| struct inode *inode = data->inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct page *tmp_page; |
| int err; |
| |
| if (!data->ff) { |
| err = -EIO; |
| data->ff = fuse_write_file_get(fc, fi); |
| if (!data->ff) |
| goto out_unlock; |
| } |
| |
| if (wpa && fuse_writepage_need_send(fc, page, ap, data)) { |
| fuse_writepages_send(data); |
| data->wpa = 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 ap->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->wpa == NULL) { |
| err = -ENOMEM; |
| wpa = fuse_writepage_args_alloc(); |
| if (!wpa) { |
| __free_page(tmp_page); |
| goto out_unlock; |
| } |
| data->max_pages = 1; |
| |
| ap = &wpa->ia.ap; |
| fuse_write_args_fill(&wpa->ia, data->ff, page_offset(page), 0); |
| wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE; |
| wpa->next = NULL; |
| ap->args.in_pages = true; |
| ap->args.end = fuse_writepage_end; |
| ap->num_pages = 0; |
| wpa->inode = inode; |
| } |
| set_page_writeback(page); |
| |
| copy_highpage(tmp_page, page); |
| ap->pages[ap->num_pages] = tmp_page; |
| ap->descs[ap->num_pages].offset = 0; |
| ap->descs[ap->num_pages].length = PAGE_SIZE; |
| data->orig_pages[ap->num_pages] = page; |
| |
| inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK); |
| inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP); |
| |
| err = 0; |
| if (data->wpa) { |
| /* |
| * Protected by fi->lock against concurrent access by |
| * fuse_page_is_writeback(). |
| */ |
| spin_lock(&fi->lock); |
| ap->num_pages++; |
| spin_unlock(&fi->lock); |
| } else if (fuse_writepage_add(wpa, page)) { |
| data->wpa = wpa; |
| } else { |
| end_page_writeback(page); |
| } |
| 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_conn *fc = get_fuse_conn(inode); |
| struct fuse_fill_wb_data data; |
| int err; |
| |
| err = -EIO; |
| if (is_bad_inode(inode)) |
| goto out; |
| |
| data.inode = inode; |
| data.wpa = NULL; |
| data.ff = NULL; |
| |
| err = -ENOMEM; |
| data.orig_pages = kcalloc(fc->max_pages, |
| sizeof(struct page *), |
| GFP_NOFS); |
| if (!data.orig_pages) |
| goto out; |
| |
| err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data); |
| if (data.wpa) { |
| WARN_ON(!data.wpa->ia.ap.num_pages); |
| fuse_writepages_send(&data); |
| } |
| if (data.ff) |
| fuse_file_put(data.ff, false, false); |
| |
| kfree(data.orig_pages); |
| out: |
| return err; |
| } |
| |
| /* |
| * It's worthy to make sure that space is reserved on disk for the write, |
| * but how to implement it without killing performance need more thinking. |
| */ |
| static int fuse_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| pgoff_t index = pos >> PAGE_SHIFT; |
| struct fuse_conn *fc = get_fuse_conn(file_inode(file)); |
| struct page *page; |
| loff_t fsize; |
| int err = -ENOMEM; |
| |
| WARN_ON(!fc->writeback_cache); |
| |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) |
| goto error; |
| |
| fuse_wait_on_page_writeback(mapping->host, page->index); |
| |
| if (PageUptodate(page) || len == PAGE_SIZE) |
| goto success; |
| /* |
| * Check if the start this page comes after the end of file, in which |
| * case the readpage can be optimized away. |
| */ |
| fsize = i_size_read(mapping->host); |
| if (fsize <= (pos & PAGE_MASK)) { |
| size_t off = pos & ~PAGE_MASK; |
| if (off) |
| zero_user_segment(page, 0, off); |
| goto success; |
| } |
| err = fuse_do_readpage(file, page); |
| if (err) |
| goto cleanup; |
| success: |
| *pagep = page; |
| return 0; |
| |
| cleanup: |
| unlock_page(page); |
| put_page(page); |
| error: |
| return err; |
| } |
| |
| static int fuse_write_end(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| struct inode *inode = page->mapping->host; |
| |
| /* Haven't copied anything? Skip zeroing, size extending, dirtying. */ |
| if (!copied) |
| goto unlock; |
| |
| if (!PageUptodate(page)) { |
| /* Zero any unwritten bytes at the end of the page */ |
| size_t endoff = (pos + copied) & ~PAGE_MASK; |
| if (endoff) |
| zero_user_segment(page, endoff, PAGE_SIZE); |
| SetPageUptodate(page); |
| } |
| |
| fuse_write_update_size(inode, pos + copied); |
| set_page_dirty(page); |
| |
| unlock: |
| unlock_page(page); |
| put_page(page); |
| |
| return copied; |
| } |
| |
| 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 vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf) |
| { |
| struct page *page = vmf->page; |
| struct inode *inode = file_inode(vmf->vma->vm_file); |
| |
| file_update_time(vmf->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, |
| .map_pages = filemap_map_pages, |
| .page_mkwrite = fuse_page_mkwrite, |
| }; |
| |
| static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| struct fuse_file *ff = file->private_data; |
| |
| if (ff->open_flags & FOPEN_DIRECT_IO) { |
| /* 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); |
| } |
| |
| if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) |
| fuse_link_write_file(file); |
| |
| file_accessed(file); |
| vma->vm_ops = &fuse_file_vm_ops; |
| return 0; |
| } |
| |
| static int convert_fuse_file_lock(struct fuse_conn *fc, |
| 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; |
| |
| /* |
| * Convert pid into init's pid namespace. The locks API will |
| * translate it into the caller's pid namespace. |
| */ |
| rcu_read_lock(); |
| fl->fl_pid = pid_nr_ns(find_pid_ns(ffl->pid, fc->pid_ns), &init_pid_ns); |
| rcu_read_unlock(); |
| break; |
| |
| default: |
| return -EIO; |
| } |
| fl->fl_type = ffl->type; |
| return 0; |
| } |
| |
| static void fuse_lk_fill(struct fuse_args *args, struct file *file, |
| const struct file_lock *fl, int opcode, pid_t pid, |
| int flock, struct fuse_lk_in *inarg) |
| { |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| |
| memset(inarg, 0, sizeof(*inarg)); |
| inarg->fh = ff->fh; |
| inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner); |
| inarg->lk.start = fl->fl_start; |
| inarg->lk.end = fl->fl_end; |
| inarg->lk.type = fl->fl_type; |
| inarg->lk.pid = pid; |
| if (flock) |
| inarg->lk_flags |= FUSE_LK_FLOCK; |
| args->opcode = opcode; |
| args->nodeid = get_node_id(inode); |
| args->in_numargs = 1; |
| args->in_args[0].size = sizeof(*inarg); |
| args->in_args[0].value = inarg; |
| } |
| |
| 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); |
| FUSE_ARGS(args); |
| struct fuse_lk_in inarg; |
| struct fuse_lk_out outarg; |
| int err; |
| |
| fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg); |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| if (!err) |
| err = convert_fuse_file_lock(fc, &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); |
| FUSE_ARGS(args); |
| struct fuse_lk_in inarg; |
| int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK; |
| struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL; |
| pid_t pid_nr = pid_nr_ns(pid, fc->pid_ns); |
| 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_POSIX) == FL_CLOSE_POSIX) |
| return 0; |
| |
| fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg); |
| err = fuse_simple_request(fc, &args); |
| |
| /* locking is restartable */ |
| if (err == -EINTR) |
| err = -ERESTARTSYS; |
| |
| 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 = locks_lock_file_wait(file, fl); |
| } else { |
| struct fuse_file *ff = file->private_data; |
| |
| /* emulate flock with POSIX locks */ |
| 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); |
| FUSE_ARGS(args); |
| struct fuse_bmap_in inarg; |
| struct fuse_bmap_out outarg; |
| int err; |
| |
| if (!inode->i_sb->s_bdev || fc->no_bmap) |
| return 0; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.block = block; |
| inarg.blocksize = inode->i_sb->s_blocksize; |
| args.opcode = FUSE_BMAP; |
| args.nodeid = get_node_id(inode); |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| if (err == -ENOSYS) |
| fc->no_bmap = 1; |
| |
| return err ? 0 : outarg.block; |
| } |
| |
| static loff_t fuse_lseek(struct file *file, loff_t offset, int whence) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_file *ff = file->private_data; |
| FUSE_ARGS(args); |
| struct fuse_lseek_in inarg = { |
| .fh = ff->fh, |
| .offset = offset, |
| .whence = whence |
| }; |
| struct fuse_lseek_out outarg; |
| int err; |
| |
| if (fc->no_lseek) |
| goto fallback; |
| |
| args.opcode = FUSE_LSEEK; |
| args.nodeid = ff->nodeid; |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| if (err) { |
| if (err == -ENOSYS) { |
| fc->no_lseek = 1; |
| goto fallback; |
| } |
| return err; |
| } |
| |
| return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes); |
| |
| fallback: |
| err = fuse_update_attributes(inode, file); |
| if (!err) |
| return generic_file_llseek(file, offset, whence); |
| else |
| return err; |
| } |
| |
| static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) |
| { |
| loff_t retval; |
| struct inode *inode = file_inode(file); |
| |
| switch (whence) { |
| case SEEK_SET: |
| case SEEK_CUR: |
| /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */ |
| retval = generic_file_llseek(file, offset, whence); |
| break; |
| case SEEK_END: |
| inode_lock(inode); |
| retval = fuse_update_attributes(inode, file); |
| if (!retval) |
| retval = generic_file_llseek(file, offset, whence); |
| inode_unlock(inode); |
| break; |
| case SEEK_HOLE: |
| case SEEK_DATA: |
| inode_lock(inode); |
| retval = fuse_lseek(file, offset, whence); |
| inode_unlock(inode); |
| break; |
| default: |
| retval = -EINVAL; |
| } |
| |
| return retval; |
| } |
| |
| /* |
| * 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 fuse_conn *fc, struct iovec *iov, |
| size_t count) |
| { |
| size_t n; |
| u32 max = fc->max_pages << 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 iovec *iov_page = NULL; |
| struct iovec *in_iov = NULL, *out_iov = NULL; |
| unsigned int in_iovs = 0, out_iovs = 0, max_pages; |
| size_t in_size, out_size, c; |
| ssize_t transferred; |
| int err, i; |
| struct iov_iter ii; |
| struct fuse_args_pages ap = {}; |
| |
| #if BITS_PER_LONG == 32 |
| inarg.flags |= FUSE_IOCTL_32BIT; |
| #else |
| if (flags & FUSE_IOCTL_COMPAT) { |
| inarg.flags |= FUSE_IOCTL_32BIT; |
| #ifdef CONFIG_X86_X32 |
| if (in_x32_syscall()) |
| inarg.flags |= FUSE_IOCTL_COMPAT_X32; |
| #endif |
| } |
| #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; |
| ap.pages = fuse_pages_alloc(fc->max_pages, GFP_KERNEL, &ap.descs); |
| iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); |
| if (!ap.pages || !iov_page) |
| goto out; |
| |
| fuse_page_descs_length_init(ap.descs, 0, fc->max_pages); |
| |
| /* |
| * 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; |
| |
| switch (cmd) { |
| case FS_IOC_GETFLAGS: |
| case FS_IOC_SETFLAGS: |
| iov->iov_len = sizeof(int); |
| break; |
| default: |
| iov->iov_len = _IOC_SIZE(cmd); |
| break; |
| } |
| |
| 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 > fc->max_pages) |
| goto out; |
| while (ap.num_pages < max_pages) { |
| ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); |
| if (!ap.pages[ap.num_pages]) |
| goto out; |
| ap.num_pages++; |
| } |
| |
| |
| /* okay, let's send it to the client */ |
| ap.args.opcode = FUSE_IOCTL; |
| ap.args.nodeid = ff->nodeid; |
| ap.args.in_numargs = 1; |
| ap.args.in_args[0].size = sizeof(inarg); |
| ap.args.in_args[0].value = &inarg; |
| if (in_size) { |
| ap.args.in_numargs++; |
| ap.args.in_args[1].size = in_size; |
| ap.args.in_pages = true; |
| |
| err = -EFAULT; |
| iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size); |
| for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { |
| c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii); |
| if (c != PAGE_SIZE && iov_iter_count(&ii)) |
| goto out; |
| } |
| } |
| |
| ap.args.out_numargs = 2; |
| ap.args.out_args[0].size = sizeof(outarg); |
| ap.args.out_args[0].value = &outarg; |
| ap.args.out_args[1].size = out_size; |
| ap.args.out_pages = true; |
| ap.args.out_argvar = true; |
| |
| transferred = fuse_simple_request(fc, &ap.args); |
| err = transferred; |
| if (transferred < 0) |
| 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(ap.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(fc, in_iov, in_iovs); |
| if (err) |
| goto out; |
| |
| err = fuse_verify_ioctl_iov(fc, out_iov, out_iovs); |
| if (err) |
| goto out; |
| |
| goto retry; |
| } |
| |
| err = -EIO; |
| if (transferred > inarg.out_size) |
| goto out; |
| |
| err = -EFAULT; |
| iov_iter_init(&ii, READ, out_iov, out_iovs, transferred); |
| for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { |
| c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii); |
| if (c != PAGE_SIZE && iov_iter_count(&ii)) |
| goto out; |
| } |
| err = 0; |
| out: |
| free_page((unsigned long) iov_page); |
| while (ap.num_pages) |
| __free_page(ap.pages[--ap.num_pages]); |
| kfree(ap.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); |
| } |
| |
| __poll_t 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; |
| FUSE_ARGS(args); |
| int err; |
| |
| if (fc->no_poll) |
| return DEFAULT_POLLMASK; |
| |
| poll_wait(file, &ff->poll_wait, wait); |
| inarg.events = mangle_poll(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); |
| } |
| |
| args.opcode = FUSE_POLL; |
| args.nodeid = ff->nodeid; |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| |
| if (!err) |
| return demangle_poll(outarg.revents); |
| if (err == -ENOSYS) { |
| fc->no_poll = 1; |
| return DEFAULT_POLLMASK; |
| } |
| return EPOLLERR; |
| } |
| 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(file_dentry(file), &attr, file); |
| } |
| |
| static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off) |
| { |
| return round_up(off, fc->max_pages << PAGE_SHIFT); |
| } |
| |
| static ssize_t |
| fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
| { |
| DECLARE_COMPLETION_ONSTACK(wait); |
| ssize_t ret = 0; |
| struct file *file = iocb->ki_filp; |
| struct fuse_file *ff = file->private_data; |
| loff_t pos = 0; |
| struct inode *inode; |
| loff_t i_size; |
| size_t count = iov_iter_count(iter), shortened = 0; |
| loff_t offset = iocb->ki_pos; |
| struct fuse_io_priv *io; |
| |
| pos = offset; |
| inode = file->f_mapping->host; |
| i_size = i_size_read(inode); |
| |
| if ((iov_iter_rw(iter) == READ) && (offset >= i_size)) |
| return 0; |
| |
| io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL); |
| if (!io) |
| return -ENOMEM; |
| spin_lock_init(&io->lock); |
| kref_init(&io->refcnt); |
| io->reqs = 1; |
| io->bytes = -1; |
| io->size = 0; |
| io->offset = offset; |
| io->write = (iov_iter_rw(iter) == WRITE); |
| io->err = 0; |
| /* |
| * By default, we want to optimize all I/Os with async request |
| * submission to the client filesystem if supported. |
| */ |
| io->async = ff->fc->async_dio; |
| io->iocb = iocb; |
| io->blocking = is_sync_kiocb(iocb); |
| |
| /* optimization for short read */ |
| if (io->async && !io->write && offset + count > i_size) { |
| iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset)); |
| shortened = count - iov_iter_count(iter); |
| count -= shortened; |
| } |
| |
| /* |
| * We cannot asynchronously extend the size of a file. |
| * In such case the aio will behave exactly like sync io. |
| */ |
| if ((offset + count > i_size) && io->write) |
| io->blocking = true; |
| |
| if (io->async && io->blocking) { |
| /* |
| * Additional reference to keep io around after |
| * calling fuse_aio_complete() |
| */ |
| kref_get(&io->refcnt); |
| io->done = &wait; |
| } |
| |
| if (iov_iter_rw(iter) == WRITE) { |
| ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE); |
| fuse_invalidate_attr(inode); |
| } else { |
| ret = __fuse_direct_read(io, iter, &pos); |
| } |
| iov_iter_reexpand(iter, iov_iter_count(iter) + shortened); |
| |
| if (io->async) { |
| bool blocking = io->blocking; |
| |
| fuse_aio_complete(io, ret < 0 ? ret : 0, -1); |
| |
| /* we have a non-extending, async request, so return */ |
| if (!blocking) |
| return -EIOCBQUEUED; |
| |
| wait_for_completion(&wait); |
| ret = fuse_get_res_by_io(io); |
| } |
| |
| kref_put(&io->refcnt, fuse_io_release); |
| |
| if (iov_iter_rw(iter) == 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 int fuse_writeback_range(struct inode *inode, loff_t start, loff_t end) |
| { |
| int err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| |
| if (!err) |
| fuse_sync_writes(inode); |
| |
| return err; |
| } |
| |
| 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_inode(file); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_conn *fc = ff->fc; |
| FUSE_ARGS(args); |
| 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 (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| return -EOPNOTSUPP; |
| |
| if (fc->no_fallocate) |
| return -EOPNOTSUPP; |
| |
| if (lock_inode) { |
| inode_lock(inode); |
| if (mode & FALLOC_FL_PUNCH_HOLE) { |
| loff_t endbyte = offset + length - 1; |
| |
| err = fuse_writeback_range(inode, offset, endbyte); |
| if (err) |
| goto out; |
| } |
| } |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && |
| offset + length > i_size_read(inode)) { |
| err = inode_newsize_ok(inode, offset + length); |
| if (err) |
| goto out; |
| } |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| |
| args.opcode = FUSE_FALLOCATE; |
| args.nodeid = ff->nodeid; |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| err = fuse_simple_request(fc, &args); |
| if (err == -ENOSYS) { |
| fc->no_fallocate = 1; |
| err = -EOPNOTSUPP; |
| } |
| if (err) |
| goto out; |
| |
| /* we could have extended the file */ |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) { |
| bool changed = fuse_write_update_size(inode, offset + length); |
| |
| if (changed && fc->writeback_cache) |
| file_update_time(file); |
| } |
| |
| 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) |
| inode_unlock(inode); |
| |
| return err; |
| } |
| |
| static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in, |
| struct file *file_out, loff_t pos_out, |
| size_t len, unsigned int flags) |
| { |
| struct fuse_file *ff_in = file_in->private_data; |
| struct fuse_file *ff_out = file_out->private_data; |
| struct inode *inode_in = file_inode(file_in); |
| struct inode *inode_out = file_inode(file_out); |
| struct fuse_inode *fi_out = get_fuse_inode(inode_out); |
| struct fuse_conn *fc = ff_in->fc; |
| FUSE_ARGS(args); |
| struct fuse_copy_file_range_in inarg = { |
| .fh_in = ff_in->fh, |
| .off_in = pos_in, |
| .nodeid_out = ff_out->nodeid, |
| .fh_out = ff_out->fh, |
| .off_out = pos_out, |
| .len = len, |
| .flags = flags |
| }; |
| struct fuse_write_out outarg; |
| ssize_t err; |
| /* mark unstable when write-back is not used, and file_out gets |
| * extended */ |
| bool is_unstable = (!fc->writeback_cache) && |
| ((pos_out + len) > inode_out->i_size); |
| |
| if (fc->no_copy_file_range) |
| return -EOPNOTSUPP; |
| |
| if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) |
| return -EXDEV; |
| |
| inode_lock(inode_in); |
| err = fuse_writeback_range(inode_in, pos_in, pos_in + len - 1); |
| inode_unlock(inode_in); |
| if (err) |
| return err; |
| |
| inode_lock(inode_out); |
| |
| err = file_modified(file_out); |
| if (err) |
| goto out; |
| |
| /* |
| * Write out dirty pages in the destination file before sending the COPY |
| * request to userspace. After the request is completed, truncate off |
| * pages (including partial ones) from the cache that have been copied, |
| * since these contain stale data at that point. |
| * |
| * This should be mostly correct, but if the COPY writes to partial |
| * pages (at the start or end) and the parts not covered by the COPY are |
| * written through a memory map after calling fuse_writeback_range(), |
| * then these partial page modifications will be lost on truncation. |
| * |
| * It is unlikely that someone would rely on such mixed style |
| * modifications. Yet this does give less guarantees than if the |
| * copying was performed with write(2). |
| * |
| * To fix this a i_mmap_sem style lock could be used to prevent new |
| * faults while the copy is ongoing. |
| */ |
| err = fuse_writeback_range(inode_out, pos_out, pos_out + len - 1); |
| if (err) |
| goto out; |
| |
| if (is_unstable) |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state); |
| |
| args.opcode = FUSE_COPY_FILE_RANGE; |
| args.nodeid = ff_in->nodeid; |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| if (err == -ENOSYS) { |
| fc->no_copy_file_range = 1; |
| err = -EOPNOTSUPP; |
| } |
| if (err) |
| goto out; |
| |
| truncate_inode_pages_range(inode_out->i_mapping, |
| ALIGN_DOWN(pos_out, PAGE_SIZE), |
| ALIGN(pos_out + outarg.size, PAGE_SIZE) - 1); |
| |
| if (fc->writeback_cache) { |
| fuse_write_update_size(inode_out, pos_out + outarg.size); |
| file_update_time(file_out); |
| } |
| |
| fuse_invalidate_attr(inode_out); |
| |
| err = outarg.size; |
| out: |
| if (is_unstable) |
| clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state); |
| |
| inode_unlock(inode_out); |
| file_accessed(file_in); |
| |
| return err; |
| } |
| |
| static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off, |
| struct file *dst_file, loff_t dst_off, |
| size_t len, unsigned int flags) |
| { |
| ssize_t ret; |
| |
| ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off, |
| len, flags); |
| |
| if (ret == -EOPNOTSUPP || ret == -EXDEV) |
| ret = generic_copy_file_range(src_file, src_off, dst_file, |
| dst_off, len, flags); |
| return ret; |
| } |
| |
| static const struct file_operations fuse_file_operations = { |
| .llseek = fuse_file_llseek, |
| .read_iter = fuse_file_read_iter, |
| .write_iter = fuse_file_write_iter, |
| .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, |
| .splice_write = iter_file_splice_write, |
| .unlocked_ioctl = fuse_file_ioctl, |
| .compat_ioctl = fuse_file_compat_ioctl, |
| .poll = fuse_file_poll, |
| .fallocate = fuse_file_fallocate, |
| .copy_file_range = fuse_copy_file_range, |
| }; |
| |
| static const struct address_space_operations fuse_file_aops = { |
| .readpage = fuse_readpage, |
| .readahead = fuse_readahead, |
| .writepage = fuse_writepage, |
| .writepages = fuse_writepages, |
| .launder_page = fuse_launder_page, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .bmap = fuse_bmap, |
| .direct_IO = fuse_direct_IO, |
| .write_begin = fuse_write_begin, |
| .write_end = fuse_write_end, |
| }; |
| |
| void fuse_init_file_inode(struct inode *inode) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| inode->i_fop = &fuse_file_operations; |
| inode->i_data.a_ops = &fuse_file_aops; |
| |
| INIT_LIST_HEAD(&fi->write_files); |
| INIT_LIST_HEAD(&fi->queued_writes); |
| fi->writectr = 0; |
| init_waitqueue_head(&fi->page_waitq); |
| fi->writepages = RB_ROOT; |
| } |