--- /dev/null
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse_i.h"
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/compat.h>
+#include <linux/swap.h>
+#include <linux/falloc.h>
+#include <linux/uio.h>
+
+static const struct file_operations fuse_direct_io_file_operations;
+
+static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
+ int opcode, struct fuse_open_out *outargp)
+{
+ struct fuse_open_in inarg;
+ 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.in.h.opcode = opcode;
+ args.in.h.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_file *fuse_file_alloc(struct fuse_conn *fc)
+{
+ struct fuse_file *ff;
+
+ ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
+ if (unlikely(!ff))
+ return NULL;
+
+ ff->fc = fc;
+ ff->reserved_req = fuse_request_alloc(0);
+ if (unlikely(!ff->reserved_req)) {
+ kfree(ff);
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&ff->write_entry);
+ atomic_set(&ff->count, 0);
+ RB_CLEAR_NODE(&ff->polled_node);
+ init_waitqueue_head(&ff->poll_wait);
+
+ spin_lock(&fc->lock);
+ ff->kh = ++fc->khctr;
+ spin_unlock(&fc->lock);
+
+ return ff;
+}
+
+void fuse_file_free(struct fuse_file *ff)
+{
+ fuse_request_free(ff->reserved_req);
+ kfree(ff);
+}
+
+struct fuse_file *fuse_file_get(struct fuse_file *ff)
+{
+ atomic_inc(&ff->count);
+ return ff;
+}
+
+static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
+{
+ iput(req->misc.release.inode);
+}
+
+static void fuse_file_put(struct fuse_file *ff, bool sync)
+{
+ if (atomic_dec_and_test(&ff->count)) {
+ struct fuse_req *req = ff->reserved_req;
+
+ if (ff->fc->no_open) {
+ /*
+ * Drop the release request when client does not
+ * implement 'open'
+ */
+ req->background = 0;
+ iput(req->misc.release.inode);
+ fuse_put_request(ff->fc, req);
+ } else if (sync) {
+ req->background = 0;
+ fuse_request_send(ff->fc, req);
+ iput(req->misc.release.inode);
+ fuse_put_request(ff->fc, req);
+ } else {
+ req->end = fuse_release_end;
+ req->background = 1;
+ fuse_request_send_background(ff->fc, req);
+ }
+ kfree(ff);
+ }
+}
+
+int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
+ bool isdir)
+{
+ struct fuse_file *ff;
+ int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
+
+ ff = fuse_file_alloc(fc);
+ if (!ff)
+ return -ENOMEM;
+
+ ff->fh = 0;
+ ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */
+ if (!fc->no_open || isdir) {
+ 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 || isdir) {
+ fuse_file_free(ff);
+ return err;
+ } else {
+ fc->no_open = 1;
+ }
+ }
+
+ if (isdir)
+ ff->open_flags &= ~FOPEN_DIRECT_IO;
+
+ ff->nodeid = nodeid;
+ file->private_data = fuse_file_get(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_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ struct fuse_file *ff = file->private_data;
+ /*
+ * file may be written through mmap, so chain it onto the
+ * inodes's write_file list
+ */
+ spin_lock(&fc->lock);
+ if (list_empty(&ff->write_entry))
+ list_add(&ff->write_entry, &fi->write_files);
+ spin_unlock(&fc->lock);
+}
+
+void fuse_finish_open(struct inode *inode, struct file *file)
+{
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (ff->open_flags & FOPEN_DIRECT_IO)
+ file->f_op = &fuse_direct_io_file_operations;
+ if (!(ff->open_flags & FOPEN_KEEP_CACHE))
+ invalidate_inode_pages2(inode->i_mapping);
+ if (ff->open_flags & FOPEN_NONSEEKABLE)
+ nonseekable_open(inode, file);
+ if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ i_size_write(inode, 0);
+ spin_unlock(&fc->lock);
+ fuse_invalidate_attr(inode);
+ 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 lock_inode = (file->f_flags & O_TRUNC) &&
+ fc->atomic_o_trunc &&
+ fc->writeback_cache;
+
+ err = generic_file_open(inode, file);
+ if (err)
+ return err;
+
+ if (lock_inode)
+ mutex_lock(&inode->i_mutex);
+
+ err = fuse_do_open(fc, get_node_id(inode), file, isdir);
+
+ if (!err)
+ fuse_finish_open(inode, file);
+
+ if (lock_inode)
+ mutex_unlock(&inode->i_mutex);
+
+ return err;
+}
+
+static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
+{
+ struct fuse_conn *fc = ff->fc;
+ struct fuse_req *req = ff->reserved_req;
+ struct fuse_release_in *inarg = &req->misc.release.in;
+
+ spin_lock(&fc->lock);
+ list_del(&ff->write_entry);
+ if (!RB_EMPTY_NODE(&ff->polled_node))
+ rb_erase(&ff->polled_node, &fc->polled_files);
+ spin_unlock(&fc->lock);
+
+ wake_up_interruptible_all(&ff->poll_wait);
+
+ inarg->fh = ff->fh;
+ inarg->flags = flags;
+ req->in.h.opcode = opcode;
+ req->in.h.nodeid = ff->nodeid;
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(struct fuse_release_in);
+ req->in.args[0].value = inarg;
+}
+
+void fuse_release_common(struct file *file, int opcode)
+{
+ struct fuse_file *ff;
+ struct fuse_req *req;
+
+ ff = file->private_data;
+ if (unlikely(!ff))
+ return;
+
+ req = ff->reserved_req;
+ fuse_prepare_release(ff, file->f_flags, opcode);
+
+ if (ff->flock) {
+ struct fuse_release_in *inarg = &req->misc.release.in;
+ inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
+ inarg->lock_owner = fuse_lock_owner_id(ff->fc,
+ (fl_owner_t) file);
+ }
+ /* Hold inode until release is finished */
+ req->misc.release.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_req != NULL);
+}
+
+static int fuse_open(struct inode *inode, struct file *file)
+{
+ return fuse_open_common(inode, file, false);
+}
+
+static int fuse_release(struct inode *inode, struct file *file)
+{
+ 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, FUSE_RELEASE);
+
+ /* return value is ignored by VFS */
+ return 0;
+}
+
+void fuse_sync_release(struct fuse_file *ff, int flags)
+{
+ WARN_ON(atomic_read(&ff->count) > 1);
+ fuse_prepare_release(ff, flags, FUSE_RELEASE);
+ ff->reserved_req->force = 1;
+ ff->reserved_req->background = 0;
+ fuse_request_send(ff->fc, ff->reserved_req);
+ fuse_put_request(ff->fc, ff->reserved_req);
+ kfree(ff);
+}
+EXPORT_SYMBOL_GPL(fuse_sync_release);
+
+/*
+ * Scramble the ID space with XTEA, so that the value of the files_struct
+ * pointer is not exposed to userspace.
+ */
+u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
+{
+ u32 *k = fc->scramble_key;
+ u64 v = (unsigned long) id;
+ u32 v0 = v;
+ u32 v1 = v >> 32;
+ u32 sum = 0;
+ int i;
+
+ for (i = 0; i < 32; i++) {
+ v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
+ sum += 0x9E3779B9;
+ v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
+ }
+
+ return (u64) v0 + ((u64) v1 << 32);
+}
+
+/*
+ * Check if 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_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ struct fuse_req *req;
+ bool found = false;
+
+ spin_lock(&fc->lock);
+ list_for_each_entry(req, &fi->writepages, writepages_entry) {
+ pgoff_t curr_index;
+
+ BUG_ON(req->inode != inode);
+ curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+ if (idx_from < curr_index + req->num_pages &&
+ curr_index <= idx_to) {
+ found = true;
+ break;
+ }
+ }
+ spin_unlock(&fc->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 int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
+{
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
+ return 0;
+}
+
+/*
+ * 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_req *req;
+ struct fuse_flush_in inarg;
+ int err;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ if (fc->no_flush)
+ return 0;
+
+ err = write_inode_now(inode, 1);
+ if (err)
+ return err;
+
+ mutex_lock(&inode->i_mutex);
+ fuse_sync_writes(inode);
+ mutex_unlock(&inode->i_mutex);
+
+ req = fuse_get_req_nofail_nopages(fc, file);
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.fh = ff->fh;
+ inarg.lock_owner = fuse_lock_owner_id(fc, id);
+ req->in.h.opcode = FUSE_FLUSH;
+ req->in.h.nodeid = get_node_id(inode);
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(inarg);
+ req->in.args[0].value = &inarg;
+ req->force = 1;
+ fuse_request_send(fc, req);
+ err = req->out.h.error;
+ fuse_put_request(fc, req);
+ if (err == -ENOSYS) {
+ fc->no_flush = 1;
+ err = 0;
+ }
+ return err;
+}
+
+int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
+ int datasync, int isdir)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_file *ff = file->private_data;
+ FUSE_ARGS(args);
+ struct fuse_fsync_in inarg;
+ int err;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ mutex_lock(&inode->i_mutex);
+
+ /*
+ * Start writeback against all dirty pages of the inode, then
+ * wait for all outstanding writes, before sending the FSYNC
+ * request.
+ */
+ err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (err)
+ goto out;
+
+ fuse_sync_writes(inode);
+ err = sync_inode_metadata(inode, 1);
+ if (err)
+ goto out;
+
+ if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
+ goto out;
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.fh = ff->fh;
+ inarg.fsync_flags = datasync ? 1 : 0;
+ args.in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
+ args.in.h.nodeid = get_node_id(inode);
+ 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) {
+ if (isdir)
+ fc->no_fsyncdir = 1;
+ else
+ fc->no_fsync = 1;
+ err = 0;
+ }
+out:
+ mutex_unlock(&inode->i_mutex);
+ return err;
+}
+
+static int fuse_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ return fuse_fsync_common(file, start, end, datasync, 0);
+}
+
+void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
+ size_t count, int opcode)
+{
+ struct fuse_read_in *inarg = &req->misc.read.in;
+ struct fuse_file *ff = file->private_data;
+
+ inarg->fh = ff->fh;
+ inarg->offset = pos;
+ inarg->size = count;
+ inarg->flags = file->f_flags;
+ req->in.h.opcode = opcode;
+ req->in.h.nodeid = ff->nodeid;
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(struct fuse_read_in);
+ req->in.args[0].value = inarg;
+ req->out.argvar = 1;
+ req->out.numargs = 1;
+ req->out.args[0].size = count;
+}
+
+static void fuse_release_user_pages(struct fuse_req *req, int write)
+{
+ unsigned i;
+
+ for (i = 0; i < req->num_pages; i++) {
+ struct page *page = req->pages[i];
+ if (write)
+ set_page_dirty_lock(page);
+ put_page(page);
+ }
+}
+
+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)
+{
+ bool is_sync = is_sync_kiocb(io->iocb);
+ 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 && is_sync)
+ complete(io->done);
+ spin_unlock(&io->lock);
+
+ if (!left && !is_sync) {
+ 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(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ spin_unlock(&fc->lock);
+ }
+
+ io->iocb->ki_complete(io->iocb, res, 0);
+ kfree(io);
+ }
+}
+
+static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
+{
+ struct fuse_io_priv *io = req->io;
+ ssize_t pos = -1;
+
+ fuse_release_user_pages(req, !io->write);
+
+ if (io->write) {
+ if (req->misc.write.in.size != req->misc.write.out.size)
+ pos = req->misc.write.in.offset - io->offset +
+ req->misc.write.out.size;
+ } else {
+ if (req->misc.read.in.size != req->out.args[0].size)
+ pos = req->misc.read.in.offset - io->offset +
+ req->out.args[0].size;
+ }
+
+ fuse_aio_complete(io, req->out.h.error, pos);
+}
+
+static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
+ size_t num_bytes, struct fuse_io_priv *io)
+{
+ spin_lock(&io->lock);
+ io->size += num_bytes;
+ io->reqs++;
+ spin_unlock(&io->lock);
+
+ req->io = io;
+ req->end = fuse_aio_complete_req;
+
+ __fuse_get_request(req);
+ fuse_request_send_background(fc, req);
+
+ return num_bytes;
+}
+
+static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
+ loff_t pos, size_t count, fl_owner_t owner)
+{
+ struct file *file = io->file;
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = ff->fc;
+
+ fuse_read_fill(req, file, pos, count, FUSE_READ);
+ if (owner != NULL) {
+ struct fuse_read_in *inarg = &req->misc.read.in;
+
+ inarg->read_flags |= FUSE_READ_LOCKOWNER;
+ inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+ }
+
+ if (io->async)
+ return fuse_async_req_send(fc, req, count, io);
+
+ fuse_request_send(fc, req);
+ return req->out.args[0].size;
+}
+
+static void fuse_read_update_size(struct inode *inode, loff_t size,
+ u64 attr_ver)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ if (attr_ver == fi->attr_version && size < inode->i_size &&
+ !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
+ fi->attr_version = ++fc->attr_version;
+ i_size_write(inode, size);
+ }
+ spin_unlock(&fc->lock);
+}
+
+static void fuse_short_read(struct fuse_req *req, struct inode *inode,
+ u64 attr_ver)
+{
+ size_t num_read = req->out.args[0].size;
+ 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_CACHE_SHIFT;
+ size_t off = num_read & (PAGE_CACHE_SIZE - 1);
+
+ for (i = start_idx; i < req->num_pages; i++) {
+ zero_user_segment(req->pages[i], off, PAGE_CACHE_SIZE);
+ off = 0;
+ }
+ } else {
+ loff_t pos = page_offset(req->pages[0]) + num_read;
+ fuse_read_update_size(inode, pos, attr_ver);
+ }
+}
+
+static int fuse_do_readpage(struct file *file, struct page *page)
+{
+ struct fuse_io_priv io = { .async = 0, .file = file };
+ struct inode *inode = page->mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ size_t num_read;
+ loff_t pos = page_offset(page);
+ size_t count = PAGE_CACHE_SIZE;
+ u64 attr_ver;
+ int err;
+
+ /*
+ * Page writeback can extend beyond the lifetime of the
+ * page-cache page, so make sure we read a properly synced
+ * page.
+ */
+ fuse_wait_on_page_writeback(inode, page->index);
+
+ req = fuse_get_req(fc, 1);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ attr_ver = fuse_get_attr_version(fc);
+
+ req->out.page_zeroing = 1;
+ req->out.argpages = 1;
+ req->num_pages = 1;
+ req->pages[0] = page;
+ req->page_descs[0].length = count;
+ num_read = fuse_send_read(req, &io, pos, count, NULL);
+ err = req->out.h.error;
+
+ if (!err) {
+ /*
+ * Short read means EOF. If file size is larger, truncate it
+ */
+ if (num_read < count)
+ fuse_short_read(req, inode, attr_ver);
+
+ SetPageUptodate(page);
+ }
+
+ fuse_put_request(fc, req);
+
+ return err;
+}
+
+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_req *req)
+{
+ int i;
+ size_t count = req->misc.read.in.size;
+ size_t num_read = req->out.args[0].size;
+ struct address_space *mapping = NULL;
+
+ for (i = 0; mapping == NULL && i < req->num_pages; i++)
+ mapping = req->pages[i]->mapping;
+
+ if (mapping) {
+ struct inode *inode = mapping->host;
+
+ /*
+ * Short read means EOF. If file size is larger, truncate it
+ */
+ if (!req->out.h.error && num_read < count)
+ fuse_short_read(req, inode, req->misc.read.attr_ver);
+
+ fuse_invalidate_atime(inode);
+ }
+
+ for (i = 0; i < req->num_pages; i++) {
+ struct page *page = req->pages[i];
+ if (!req->out.h.error)
+ SetPageUptodate(page);
+ else
+ SetPageError(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ if (req->ff)
+ fuse_file_put(req->ff, false);
+}
+
+static void fuse_send_readpages(struct fuse_req *req, struct file *file)
+{
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = ff->fc;
+ loff_t pos = page_offset(req->pages[0]);
+ size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+
+ req->out.argpages = 1;
+ req->out.page_zeroing = 1;
+ req->out.page_replace = 1;
+ fuse_read_fill(req, file, pos, count, FUSE_READ);
+ req->misc.read.attr_ver = fuse_get_attr_version(fc);
+ if (fc->async_read) {
+ req->ff = fuse_file_get(ff);
+ req->end = fuse_readpages_end;
+ fuse_request_send_background(fc, req);
+ } else {
+ fuse_request_send(fc, req);
+ fuse_readpages_end(fc, req);
+ fuse_put_request(fc, req);
+ }
+}
+
+struct fuse_fill_data {
+ struct fuse_req *req;
+ struct file *file;
+ struct inode *inode;
+ unsigned nr_pages;
+};
+
+static int fuse_readpages_fill(void *_data, struct page *page)
+{
+ struct fuse_fill_data *data = _data;
+ struct fuse_req *req = data->req;
+ struct inode *inode = data->inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ fuse_wait_on_page_writeback(inode, page->index);
+
+ if (req->num_pages &&
+ (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
+ (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
+ req->pages[req->num_pages - 1]->index + 1 != page->index)) {
+ int nr_alloc = min_t(unsigned, data->nr_pages,
+ FUSE_MAX_PAGES_PER_REQ);
+ fuse_send_readpages(req, data->file);
+ if (fc->async_read)
+ req = fuse_get_req_for_background(fc, nr_alloc);
+ else
+ req = fuse_get_req(fc, nr_alloc);
+
+ data->req = req;
+ if (IS_ERR(req)) {
+ unlock_page(page);
+ return PTR_ERR(req);
+ }
+ }
+
+ if (WARN_ON(req->num_pages >= req->max_pages)) {
+ fuse_put_request(fc, req);
+ return -EIO;
+ }
+
+ page_cache_get(page);
+ req->pages[req->num_pages] = page;
+ req->page_descs[req->num_pages].length = PAGE_SIZE;
+ req->num_pages++;
+ data->nr_pages--;
+ return 0;
+}
+
+static int fuse_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct inode *inode = mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_fill_data data;
+ int err;
+ int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
+
+ err = -EIO;
+ if (is_bad_inode(inode))
+ goto out;
+
+ data.file = file;
+ data.inode = inode;
+ if (fc->async_read)
+ data.req = fuse_get_req_for_background(fc, nr_alloc);
+ else
+ data.req = fuse_get_req(fc, nr_alloc);
+ data.nr_pages = nr_pages;
+ err = PTR_ERR(data.req);
+ if (IS_ERR(data.req))
+ goto out;
+
+ err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
+ if (!err) {
+ if (data.req->num_pages)
+ fuse_send_readpages(data.req, file);
+ else
+ fuse_put_request(fc, data.req);
+ }
+out:
+ return err;
+}
+
+static ssize_t fuse_file_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, NULL, iocb->ki_filp, NULL);
+ if (err)
+ return err;
+ }
+
+ return generic_file_read_iter(iocb, to);
+}
+
+static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
+ loff_t pos, size_t count)
+{
+ struct fuse_write_in *inarg = &req->misc.write.in;
+ struct fuse_write_out *outarg = &req->misc.write.out;
+
+ inarg->fh = ff->fh;
+ inarg->offset = pos;
+ inarg->size = count;
+ req->in.h.opcode = FUSE_WRITE;
+ req->in.h.nodeid = ff->nodeid;
+ req->in.numargs = 2;
+ if (ff->fc->minor < 9)
+ req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
+ else
+ req->in.args[0].size = sizeof(struct fuse_write_in);
+ req->in.args[0].value = inarg;
+ req->in.args[1].size = count;
+ req->out.numargs = 1;
+ req->out.args[0].size = sizeof(struct fuse_write_out);
+ req->out.args[0].value = outarg;
+}
+
+static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
+ loff_t pos, size_t count, fl_owner_t owner)
+{
+ struct file *file = io->file;
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = ff->fc;
+ struct fuse_write_in *inarg = &req->misc.write.in;
+
+ fuse_write_fill(req, ff, pos, count);
+ inarg->flags = file->f_flags;
+ if (owner != NULL) {
+ inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
+ inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+ }
+
+ if (io->async)
+ return fuse_async_req_send(fc, req, count, io);
+
+ fuse_request_send(fc, req);
+ return req->misc.write.out.size;
+}
+
+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(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ if (pos > inode->i_size) {
+ i_size_write(inode, pos);
+ ret = true;
+ }
+ spin_unlock(&fc->lock);
+
+ return ret;
+}
+
+static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
+ struct inode *inode, loff_t pos,
+ size_t count)
+{
+ size_t res;
+ unsigned offset;
+ unsigned i;
+ struct fuse_io_priv io = { .async = 0, .file = file };
+
+ for (i = 0; i < req->num_pages; i++)
+ fuse_wait_on_page_writeback(inode, req->pages[i]->index);
+
+ res = fuse_send_write(req, &io, pos, count, NULL);
+
+ offset = req->page_descs[0].offset;
+ count = res;
+ for (i = 0; i < req->num_pages; i++) {
+ struct page *page = req->pages[i];
+
+ if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
+ SetPageUptodate(page);
+
+ if (count > PAGE_CACHE_SIZE - offset)
+ count -= PAGE_CACHE_SIZE - offset;
+ else
+ count = 0;
+ offset = 0;
+
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
+ return res;
+}
+
+static ssize_t fuse_fill_write_pages(struct fuse_req *req,
+ struct address_space *mapping,
+ struct iov_iter *ii, loff_t pos)
+{
+ struct fuse_conn *fc = get_fuse_conn(mapping->host);
+ unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+ size_t count = 0;
+ int err;
+
+ req->in.argpages = 1;
+ req->page_descs[0].offset = offset;
+
+ do {
+ size_t tmp;
+ struct page *page;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
+ iov_iter_count(ii));
+
+ bytes = min_t(size_t, bytes, fc->max_write - count);
+
+ again:
+ err = -EFAULT;
+ if (iov_iter_fault_in_readable(ii, bytes))
+ break;
+
+ err = -ENOMEM;
+ page = grab_cache_page_write_begin(mapping, index, 0);
+ if (!page)
+ break;
+
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_page(page);
+
+ tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
+ flush_dcache_page(page);
+
+ if (!tmp) {
+ unlock_page(page);
+ page_cache_release(page);
+ bytes = min(bytes, iov_iter_single_seg_count(ii));
+ goto again;
+ }
+
+ err = 0;
+ req->pages[req->num_pages] = page;
+ req->page_descs[req->num_pages].length = tmp;
+ req->num_pages++;
+
+ iov_iter_advance(ii, tmp);
+ count += tmp;
+ pos += tmp;
+ offset += tmp;
+ if (offset == PAGE_CACHE_SIZE)
+ offset = 0;
+
+ if (!fc->big_writes)
+ break;
+ } while (iov_iter_count(ii) && count < fc->max_write &&
+ req->num_pages < req->max_pages && offset == 0);
+
+ return count > 0 ? count : err;
+}
+
+static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
+{
+ return min_t(unsigned,
+ ((pos + len - 1) >> PAGE_CACHE_SHIFT) -
+ (pos >> PAGE_CACHE_SHIFT) + 1,
+ FUSE_MAX_PAGES_PER_REQ);
+}
+
+static ssize_t fuse_perform_write(struct file *file,
+ struct address_space *mapping,
+ struct iov_iter *ii, loff_t pos)
+{
+ struct inode *inode = mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ int err = 0;
+ ssize_t res = 0;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ if (inode->i_size < pos + iov_iter_count(ii))
+ set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+
+ do {
+ struct fuse_req *req;
+ ssize_t count;
+ unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
+
+ req = fuse_get_req(fc, nr_pages);
+ if (IS_ERR(req)) {
+ err = PTR_ERR(req);
+ break;
+ }
+
+ count = fuse_fill_write_pages(req, mapping, ii, pos);
+ if (count <= 0) {
+ err = count;
+ } else {
+ size_t num_written;
+
+ num_written = fuse_send_write_pages(req, file, inode,
+ pos, count);
+ err = req->out.h.error;
+ if (!err) {
+ res += num_written;
+ pos += num_written;
+
+ /* break out of the loop on short write */
+ if (num_written != count)
+ err = -EIO;
+ }
+ }
+ fuse_put_request(fc, req);
+ } while (!err && iov_iter_count(ii));
+
+ if (res > 0)
+ fuse_write_update_size(inode, pos);
+
+ clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+ fuse_invalidate_attr(inode);
+
+ return res > 0 ? res : err;
+}
+
+static ssize_t fuse_file_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, NULL, file, NULL);
+ if (err)
+ return err;
+
+ return generic_file_write_iter(iocb, from);
+ }
+
+ mutex_lock(&inode->i_mutex);
+
+ /* 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_suid(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, pos);
+ if (written < 0 || !iov_iter_count(from))
+ goto out;
+
+ pos += written;
+
+ written_buffered = fuse_perform_write(file, 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_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+
+ written += written_buffered;
+ iocb->ki_pos = pos + written_buffered;
+ } else {
+ written = fuse_perform_write(file, mapping, from, iocb->ki_pos);
+ if (written >= 0)
+ iocb->ki_pos += written;
+ }
+out:
+ current->backing_dev_info = NULL;
+ mutex_unlock(&inode->i_mutex);
+
+ return written ? written : err;
+}
+
+static inline void fuse_page_descs_length_init(struct fuse_req *req,
+ unsigned index, unsigned nr_pages)
+{
+ int i;
+
+ for (i = index; i < index + nr_pages; i++)
+ req->page_descs[i].length = PAGE_SIZE -
+ req->page_descs[i].offset;
+}
+
+static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
+{
+ return (unsigned long)ii->iov->iov_base + ii->iov_offset;
+}
+
+static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
+ size_t max_size)
+{
+ return min(iov_iter_single_seg_count(ii), max_size);
+}
+
+static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
+ size_t *nbytesp, int write)
+{
+ size_t nbytes = 0; /* # bytes already packed in req */
+
+ /* Special case for kernel I/O: can copy directly into the buffer */
+ if (ii->type & ITER_KVEC) {
+ unsigned long user_addr = fuse_get_user_addr(ii);
+ size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
+
+ if (write)
+ req->in.args[1].value = (void *) user_addr;
+ else
+ req->out.args[0].value = (void *) user_addr;
+
+ iov_iter_advance(ii, frag_size);
+ *nbytesp = frag_size;
+ return 0;
+ }
+
+ while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
+ unsigned npages;
+ size_t start;
+ ssize_t ret = iov_iter_get_pages(ii,
+ &req->pages[req->num_pages],
+ *nbytesp - nbytes,
+ req->max_pages - req->num_pages,
+ &start);
+ if (ret < 0)
+ return ret;
+
+ iov_iter_advance(ii, ret);
+ nbytes += ret;
+
+ ret += start;
+ npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
+
+ req->page_descs[req->num_pages].offset = start;
+ fuse_page_descs_length_init(req, req->num_pages, npages);
+
+ req->num_pages += npages;
+ req->page_descs[req->num_pages - 1].length -=
+ (PAGE_SIZE - ret) & (PAGE_SIZE - 1);
+ }
+
+ if (write)
+ req->in.argpages = 1;
+ else
+ req->out.argpages = 1;
+
+ *nbytesp = nbytes;
+
+ return 0;
+}
+
+static inline int fuse_iter_npages(const struct iov_iter *ii_p)
+{
+ return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ);
+}
+
+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->file;
+ 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_CACHE_SHIFT;
+ pgoff_t idx_to = (pos + count - 1) >> PAGE_CACHE_SHIFT;
+ ssize_t res = 0;
+ struct fuse_req *req;
+
+ if (io->async)
+ req = fuse_get_req_for_background(fc, fuse_iter_npages(iter));
+ else
+ req = fuse_get_req(fc, fuse_iter_npages(iter));
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
+ if (!write)
+ mutex_lock(&inode->i_mutex);
+ fuse_sync_writes(inode);
+ if (!write)
+ mutex_unlock(&inode->i_mutex);
+ }
+
+ while (count) {
+ size_t nres;
+ fl_owner_t owner = current->files;
+ size_t nbytes = min(count, nmax);
+ int err = fuse_get_user_pages(req, iter, &nbytes, write);
+ if (err) {
+ res = err;
+ break;
+ }
+
+ if (write)
+ nres = fuse_send_write(req, io, pos, nbytes, owner);
+ else
+ nres = fuse_send_read(req, io, pos, nbytes, owner);
+
+ if (!io->async)
+ fuse_release_user_pages(req, !write);
+ if (req->out.h.error) {
+ if (!res)
+ res = req->out.h.error;
+ break;
+ } else if (nres > nbytes) {
+ res = -EIO;
+ break;
+ }
+ count -= nres;
+ res += nres;
+ pos += nres;
+ if (nres != nbytes)
+ break;
+ if (count) {
+ fuse_put_request(fc, req);
+ if (io->async)
+ req = fuse_get_req_for_background(fc,
+ fuse_iter_npages(iter));
+ else
+ req = fuse_get_req(fc, fuse_iter_npages(iter));
+ if (IS_ERR(req))
+ break;
+ }
+ }
+ if (!IS_ERR(req))
+ fuse_put_request(fc, req);
+ if (res > 0)
+ *ppos = pos;
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(fuse_direct_io);
+
+static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
+ struct iov_iter *iter,
+ loff_t *ppos)
+{
+ ssize_t res;
+ struct file *file = io->file;
+ struct inode *inode = file_inode(file);
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ res = fuse_direct_io(io, iter, ppos, 0);
+
+ fuse_invalidate_attr(inode);
+
+ return res;
+}
+
+static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct fuse_io_priv io = { .async = 0, .file = iocb->ki_filp };
+ return __fuse_direct_read(&io, to, &iocb->ki_pos);
+}
+
+static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file);
+ struct fuse_io_priv io = { .async = 0, .file = file };
+ ssize_t res;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ /* Don't allow parallel writes to the same file */
+ mutex_lock(&inode->i_mutex);
+ res = generic_write_checks(iocb, from);
+ if (res > 0)
+ 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);
+ mutex_unlock(&inode->i_mutex);
+
+ return res;
+}
+
+static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
+{
+ int i;
+
+ for (i = 0; i < req->num_pages; i++)
+ __free_page(req->pages[i]);
+
+ if (req->ff)
+ fuse_file_put(req->ff, false);
+}
+
+static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
+{
+ struct inode *inode = req->inode;
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ struct backing_dev_info *bdi = inode_to_bdi(inode);
+ int i;
+
+ list_del(&req->writepages_entry);
+ for (i = 0; i < req->num_pages; i++) {
+ dec_bdi_stat(bdi, BDI_WRITEBACK);
+ dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
+ bdi_writeout_inc(bdi);
+ }
+ wake_up(&fi->page_waitq);
+}
+
+/* Called under fc->lock, may release and reacquire it */
+static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req,
+ loff_t size)
+__releases(fc->lock)
+__acquires(fc->lock)
+{
+ struct fuse_inode *fi = get_fuse_inode(req->inode);
+ struct fuse_write_in *inarg = &req->misc.write.in;
+ __u64 data_size = req->num_pages * PAGE_CACHE_SIZE;
+
+ if (!fc->connected)
+ goto out_free;
+
+ if (inarg->offset + data_size <= size) {
+ inarg->size = data_size;
+ } else if (inarg->offset < size) {
+ inarg->size = size - inarg->offset;
+ } else {
+ /* Got truncated off completely */
+ goto out_free;
+ }
+
+ req->in.args[1].size = inarg->size;
+ fi->writectr++;
+ fuse_request_send_background_locked(fc, req);
+ return;
+
+ out_free:
+ fuse_writepage_finish(fc, req);
+ spin_unlock(&fc->lock);
+ fuse_writepage_free(fc, req);
+ fuse_put_request(fc, req);
+ spin_lock(&fc->lock);
+}
+
+/*
+ * If fi->writectr is positive (no truncate or fsync going on) send
+ * all queued writepage requests.
+ *
+ * Called with fc->lock
+ */
+void fuse_flush_writepages(struct inode *inode)
+__releases(fc->lock)
+__acquires(fc->lock)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ size_t crop = i_size_read(inode);
+ struct fuse_req *req;
+
+ while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
+ req = list_entry(fi->queued_writes.next, struct fuse_req, list);
+ list_del_init(&req->list);
+ fuse_send_writepage(fc, req, crop);
+ }
+}
+
+static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
+{
+ struct inode *inode = req->inode;
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ mapping_set_error(inode->i_mapping, req->out.h.error);
+ spin_lock(&fc->lock);
+ while (req->misc.write.next) {
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_write_in *inarg = &req->misc.write.in;
+ struct fuse_req *next = req->misc.write.next;
+ req->misc.write.next = next->misc.write.next;
+ next->misc.write.next = NULL;
+ next->ff = fuse_file_get(req->ff);
+ list_add(&next->writepages_entry, &fi->writepages);
+
+ /*
+ * 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, req);
+ spin_unlock(&fc->lock);
+ fuse_writepage_free(fc, req);
+}
+
+static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc,
+ struct fuse_inode *fi)
+{
+ struct fuse_file *ff = NULL;
+
+ spin_lock(&fc->lock);
+ if (!list_empty(&fi->write_files)) {
+ ff = list_entry(fi->write_files.next, struct fuse_file,
+ write_entry);
+ fuse_file_get(ff);
+ }
+ spin_unlock(&fc->lock);
+
+ return ff;
+}
+
+static 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, 0);
+
+ return err;
+}
+
+static int fuse_writepage_locked(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ struct fuse_req *req;
+ struct page *tmp_page;
+ int error = -ENOMEM;
+
+ set_page_writeback(page);
+
+ req = fuse_request_alloc_nofs(1);
+ if (!req)
+ goto err;
+
+ req->background = 1; /* writeback always goes to bg_queue */
+ tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (!tmp_page)
+ goto err_free;
+
+ error = -EIO;
+ req->ff = fuse_write_file_get(fc, fi);
+ if (!req->ff)
+ goto err_nofile;
+
+ fuse_write_fill(req, req->ff, page_offset(page), 0);
+
+ copy_highpage(tmp_page, page);
+ req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
+ req->misc.write.next = NULL;
+ req->in.argpages = 1;
+ req->num_pages = 1;
+ req->pages[0] = tmp_page;
+ req->page_descs[0].offset = 0;
+ req->page_descs[0].length = PAGE_SIZE;
+ req->end = fuse_writepage_end;
+ req->inode = inode;
+
+ inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
+ inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
+
+ spin_lock(&fc->lock);
+ list_add(&req->writepages_entry, &fi->writepages);
+ list_add_tail(&req->list, &fi->queued_writes);
+ fuse_flush_writepages(inode);
+ spin_unlock(&fc->lock);
+
+ end_page_writeback(page);
+
+ return 0;
+
+err_nofile:
+ __free_page(tmp_page);
+err_free:
+ fuse_request_free(req);
+err:
+ end_page_writeback(page);
+ return error;
+}
+
+static int fuse_writepage(struct page *page, struct writeback_control *wbc)
+{
+ int err;
+
+ if (fuse_page_is_writeback(page->mapping->host, page->index)) {
+ /*
+ * ->writepages() should be called for sync() and friends. We
+ * should only get here on direct reclaim and then we are
+ * allowed to skip a page which is already in flight
+ */
+ WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
+
+ redirty_page_for_writepage(wbc, page);
+ return 0;
+ }
+
+ err = fuse_writepage_locked(page);
+ unlock_page(page);
+
+ return err;
+}
+
+struct fuse_fill_wb_data {
+ struct fuse_req *req;
+ struct fuse_file *ff;
+ struct inode *inode;
+ struct page **orig_pages;
+};
+
+static void fuse_writepages_send(struct fuse_fill_wb_data *data)
+{
+ struct fuse_req *req = data->req;
+ struct inode *inode = data->inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ int num_pages = req->num_pages;
+ int i;
+
+ req->ff = fuse_file_get(data->ff);
+ spin_lock(&fc->lock);
+ list_add_tail(&req->list, &fi->queued_writes);
+ fuse_flush_writepages(inode);
+ spin_unlock(&fc->lock);
+
+ for (i = 0; i < num_pages; i++)
+ end_page_writeback(data->orig_pages[i]);
+}
+
+static bool fuse_writepage_in_flight(struct fuse_req *new_req,
+ struct page *page)
+{
+ struct fuse_conn *fc = get_fuse_conn(new_req->inode);
+ struct fuse_inode *fi = get_fuse_inode(new_req->inode);
+ struct fuse_req *tmp;
+ struct fuse_req *old_req;
+ bool found = false;
+ pgoff_t curr_index;
+
+ BUG_ON(new_req->num_pages != 0);
+
+ spin_lock(&fc->lock);
+ list_del(&new_req->writepages_entry);
+ list_for_each_entry(old_req, &fi->writepages, writepages_entry) {
+ BUG_ON(old_req->inode != new_req->inode);
+ curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+ if (curr_index <= page->index &&
+ page->index < curr_index + old_req->num_pages) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ list_add(&new_req->writepages_entry, &fi->writepages);
+ goto out_unlock;
+ }
+
+ new_req->num_pages = 1;
+ for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) {
+ BUG_ON(tmp->inode != new_req->inode);
+ curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+ if (tmp->num_pages == 1 &&
+ curr_index == page->index) {
+ old_req = tmp;
+ }
+ }
+
+ if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT ||
+ old_req->state == FUSE_REQ_PENDING)) {
+ struct backing_dev_info *bdi = inode_to_bdi(page->mapping->host);
+
+ copy_highpage(old_req->pages[0], page);
+ spin_unlock(&fc->lock);
+
+ dec_bdi_stat(bdi, BDI_WRITEBACK);
+ dec_zone_page_state(page, NR_WRITEBACK_TEMP);
+ bdi_writeout_inc(bdi);
+ fuse_writepage_free(fc, new_req);
+ fuse_request_free(new_req);
+ goto out;
+ } else {
+ new_req->misc.write.next = old_req->misc.write.next;
+ old_req->misc.write.next = new_req;
+ }
+out_unlock:
+ spin_unlock(&fc->lock);
+out:
+ return found;
+}
+
+static int fuse_writepages_fill(struct page *page,
+ struct writeback_control *wbc, void *_data)
+{
+ struct fuse_fill_wb_data *data = _data;
+ struct fuse_req *req = data->req;
+ struct inode *inode = data->inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct page *tmp_page;
+ bool is_writeback;
+ int err;
+
+ if (!data->ff) {
+ err = -EIO;
+ data->ff = fuse_write_file_get(fc, get_fuse_inode(inode));
+ if (!data->ff)
+ goto out_unlock;
+ }
+
+ /*
+ * Being under writeback is unlikely but possible. For example direct
+ * read to an mmaped fuse file will set the page dirty twice; once when
+ * the pages are faulted with get_user_pages(), and then after the read
+ * completed.
+ */
+ is_writeback = fuse_page_is_writeback(inode, page->index);
+
+ if (req && req->num_pages &&
+ (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
+ (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write ||
+ data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
+ fuse_writepages_send(data);
+ data->req = NULL;
+ }
+ err = -ENOMEM;
+ tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (!tmp_page)
+ goto out_unlock;
+
+ /*
+ * The page must not be redirtied until the writeout is completed
+ * (i.e. userspace has sent a reply to the write request). Otherwise
+ * there could be more than one temporary page instance for each real
+ * page.
+ *
+ * This is ensured by holding the page lock in page_mkwrite() while
+ * checking fuse_page_is_writeback(). We already hold the page lock
+ * since clear_page_dirty_for_io() and keep it held until we add the
+ * request to the fi->writepages list and increment req->num_pages.
+ * After this fuse_page_is_writeback() will indicate that the page is
+ * under writeback, so we can release the page lock.
+ */
+ if (data->req == NULL) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ err = -ENOMEM;
+ req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ);
+ if (!req) {
+ __free_page(tmp_page);
+ goto out_unlock;
+ }
+
+ fuse_write_fill(req, data->ff, page_offset(page), 0);
+ req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
+ req->misc.write.next = NULL;
+ req->in.argpages = 1;
+ req->background = 1;
+ req->num_pages = 0;
+ req->end = fuse_writepage_end;
+ req->inode = inode;
+
+ spin_lock(&fc->lock);
+ list_add(&req->writepages_entry, &fi->writepages);
+ spin_unlock(&fc->lock);
+
+ data->req = req;
+ }
+ set_page_writeback(page);
+
+ copy_highpage(tmp_page, page);
+ req->pages[req->num_pages] = tmp_page;
+ req->page_descs[req->num_pages].offset = 0;
+ req->page_descs[req->num_pages].length = PAGE_SIZE;
+
+ inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
+ inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
+
+ err = 0;
+ if (is_writeback && fuse_writepage_in_flight(req, page)) {
+ end_page_writeback(page);
+ data->req = NULL;
+ goto out_unlock;
+ }
+ data->orig_pages[req->num_pages] = page;
+
+ /*
+ * Protected by fc->lock against concurrent access by
+ * fuse_page_is_writeback().
+ */
+ spin_lock(&fc->lock);
+ req->num_pages++;
+ spin_unlock(&fc->lock);
+
+out_unlock:
+ unlock_page(page);
+
+ return err;
+}
+
+static int fuse_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = mapping->host;
+ struct fuse_fill_wb_data data;
+ int err;
+
+ err = -EIO;
+ if (is_bad_inode(inode))
+ goto out;
+
+ data.inode = inode;
+ data.req = NULL;
+ data.ff = NULL;
+
+ err = -ENOMEM;
+ data.orig_pages = kcalloc(FUSE_MAX_PAGES_PER_REQ,
+ sizeof(struct page *),
+ GFP_NOFS);
+ if (!data.orig_pages)
+ goto out;
+
+ err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
+ if (data.req) {
+ /* Ignore errors if we can write at least one page */
+ BUG_ON(!data.req->num_pages);
+ fuse_writepages_send(&data);
+ err = 0;
+ }
+ if (data.ff)
+ fuse_file_put(data.ff, false);
+
+ kfree(data.orig_pages);
+out:
+ return err;
+}
+
+/*
+ * 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_CACHE_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_CACHE_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_CACHE_MASK)) {
+ size_t off = pos & ~PAGE_CACHE_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);
+ page_cache_release(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;
+
+ if (!PageUptodate(page)) {
+ /* Zero any unwritten bytes at the end of the page */
+ size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK;
+ if (endoff)
+ zero_user_segment(page, endoff, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ }
+
+ fuse_write_update_size(inode, pos + copied);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(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 int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct page *page = vmf->page;
+ struct inode *inode = file_inode(vma->vm_file);
+
+ file_update_time(vma->vm_file);
+ lock_page(page);
+ if (page->mapping != inode->i_mapping) {
+ unlock_page(page);
+ return VM_FAULT_NOPAGE;
+ }
+
+ fuse_wait_on_page_writeback(inode, page->index);
+ return VM_FAULT_LOCKED;
+}
+
+static const struct vm_operations_struct fuse_file_vm_ops = {
+ .close = fuse_vma_close,
+ .fault = filemap_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = fuse_page_mkwrite,
+};
+
+static int fuse_file_mmap(struct file *file, struct vm_area_struct *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 fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ /* Can't provide the coherency needed for MAP_SHARED */
+ if (vma->vm_flags & VM_MAYSHARE)
+ return -ENODEV;
+
+ invalidate_inode_pages2(file->f_mapping);
+
+ return generic_file_mmap(file, vma);
+}
+
+static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
+ struct file_lock *fl)
+{
+ switch (ffl->type) {
+ case F_UNLCK:
+ break;
+
+ case F_RDLCK:
+ case F_WRLCK:
+ if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
+ ffl->end < ffl->start)
+ return -EIO;
+
+ fl->fl_start = ffl->start;
+ fl->fl_end = ffl->end;
+ fl->fl_pid = ffl->pid;
+ break;
+
+ default:
+ return -EIO;
+ }
+ fl->fl_type = ffl->type;
+ return 0;
+}
+
+static void fuse_lk_fill(struct fuse_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->in.h.opcode = opcode;
+ args->in.h.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(&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;
+ pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
+ int err;
+
+ if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
+ /* NLM needs asynchronous locks, which we don't support yet */
+ return -ENOLCK;
+ }
+
+ /* Unlock on close is handled by the flush method */
+ if (fl->fl_flags & FL_CLOSE)
+ return 0;
+
+ fuse_lk_fill(&args, file, fl, opcode, pid, 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 = flock_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.in.h.opcode = FUSE_BMAP;
+ args.in.h.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_file_llseek(struct file *file, loff_t offset, int whence)
+{
+ loff_t retval;
+ struct inode *inode = file_inode(file);
+
+ /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
+ if (whence == SEEK_CUR || whence == SEEK_SET)
+ return generic_file_llseek(file, offset, whence);
+
+ mutex_lock(&inode->i_mutex);
+ retval = fuse_update_attributes(inode, NULL, file, NULL);
+ if (!retval)
+ retval = generic_file_llseek(file, offset, whence);
+ mutex_unlock(&inode->i_mutex);
+
+ return retval;
+}
+
+static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
+ unsigned int nr_segs, size_t bytes, bool to_user)
+{
+ struct iov_iter ii;
+ int page_idx = 0;
+
+ if (!bytes)
+ return 0;
+
+ iov_iter_init(&ii, to_user ? READ : WRITE, iov, nr_segs, bytes);
+
+ while (iov_iter_count(&ii)) {
+ struct page *page = pages[page_idx++];
+ size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
+ void *kaddr;
+
+ kaddr = kmap(page);
+
+ while (todo) {
+ char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
+ size_t iov_len = ii.iov->iov_len - ii.iov_offset;
+ size_t copy = min(todo, iov_len);
+ size_t left;
+
+ if (!to_user)
+ left = copy_from_user(kaddr, uaddr, copy);
+ else
+ left = copy_to_user(uaddr, kaddr, copy);
+
+ if (unlikely(left))
+ return -EFAULT;
+
+ iov_iter_advance(&ii, copy);
+ todo -= copy;
+ kaddr += copy;
+ }
+
+ kunmap(page);
+ }
+
+ return 0;
+}
+
+/*
+ * CUSE servers compiled on 32bit broke on 64bit kernels because the
+ * ABI was defined to be 'struct iovec' which is different on 32bit
+ * and 64bit. Fortunately we can determine which structure the server
+ * used from the size of the reply.
+ */
+static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
+ size_t transferred, unsigned count,
+ bool is_compat)
+{
+#ifdef CONFIG_COMPAT
+ if (count * sizeof(struct compat_iovec) == transferred) {
+ struct compat_iovec *ciov = src;
+ unsigned i;
+
+ /*
+ * With this interface a 32bit server cannot support
+ * non-compat (i.e. ones coming from 64bit apps) ioctl
+ * requests
+ */
+ if (!is_compat)
+ return -EINVAL;
+
+ for (i = 0; i < count; i++) {
+ dst[i].iov_base = compat_ptr(ciov[i].iov_base);
+ dst[i].iov_len = ciov[i].iov_len;
+ }
+ return 0;
+ }
+#endif
+
+ if (count * sizeof(struct iovec) != transferred)
+ return -EIO;
+
+ memcpy(dst, src, transferred);
+ return 0;
+}
+
+/* Make sure iov_length() won't overflow */
+static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
+{
+ size_t n;
+ u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
+
+ for (n = 0; n < count; n++, iov++) {
+ if (iov->iov_len > (size_t) max)
+ return -ENOMEM;
+ max -= iov->iov_len;
+ }
+ return 0;
+}
+
+static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
+ void *src, size_t transferred, unsigned count,
+ bool is_compat)
+{
+ unsigned i;
+ struct fuse_ioctl_iovec *fiov = src;
+
+ if (fc->minor < 16) {
+ return fuse_copy_ioctl_iovec_old(dst, src, transferred,
+ count, is_compat);
+ }
+
+ if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
+ return -EIO;
+
+ for (i = 0; i < count; i++) {
+ /* Did the server supply an inappropriate value? */
+ if (fiov[i].base != (unsigned long) fiov[i].base ||
+ fiov[i].len != (unsigned long) fiov[i].len)
+ return -EIO;
+
+ dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
+ dst[i].iov_len = (size_t) fiov[i].len;
+
+#ifdef CONFIG_COMPAT
+ if (is_compat &&
+ (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
+ (compat_size_t) dst[i].iov_len != fiov[i].len))
+ return -EIO;
+#endif
+ }
+
+ return 0;
+}
+
+
+/*
+ * For ioctls, there is no generic way to determine how much memory
+ * needs to be read and/or written. Furthermore, ioctls are allowed
+ * to dereference the passed pointer, so the parameter requires deep
+ * copying but FUSE has no idea whatsoever about what to copy in or
+ * out.
+ *
+ * This is solved by allowing FUSE server to retry ioctl with
+ * necessary in/out iovecs. Let's assume the ioctl implementation
+ * needs to read in the following structure.
+ *
+ * struct a {
+ * char *buf;
+ * size_t buflen;
+ * }
+ *
+ * On the first callout to FUSE server, inarg->in_size and
+ * inarg->out_size will be NULL; then, the server completes the ioctl
+ * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
+ * the actual iov array to
+ *
+ * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
+ *
+ * which tells FUSE to copy in the requested area and retry the ioctl.
+ * On the second round, the server has access to the structure and
+ * from that it can tell what to look for next, so on the invocation,
+ * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
+ *
+ * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
+ * { .iov_base = a.buf, .iov_len = a.buflen } }
+ *
+ * FUSE will copy both struct a and the pointed buffer from the
+ * process doing the ioctl and retry ioctl with both struct a and the
+ * buffer.
+ *
+ * This time, FUSE server has everything it needs and completes ioctl
+ * without FUSE_IOCTL_RETRY which finishes the ioctl call.
+ *
+ * Copying data out works the same way.
+ *
+ * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
+ * automatically initializes in and out iovs by decoding @cmd with
+ * _IOC_* macros and the server is not allowed to request RETRY. This
+ * limits ioctl data transfers to well-formed ioctls and is the forced
+ * behavior for all FUSE servers.
+ */
+long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
+ unsigned int flags)
+{
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = ff->fc;
+ struct fuse_ioctl_in inarg = {
+ .fh = ff->fh,
+ .cmd = cmd,
+ .arg = arg,
+ .flags = flags
+ };
+ struct fuse_ioctl_out outarg;
+ struct fuse_req *req = NULL;
+ struct page **pages = NULL;
+ struct iovec *iov_page = NULL;
+ struct iovec *in_iov = NULL, *out_iov = NULL;
+ unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
+ size_t in_size, out_size, transferred;
+ int err;
+
+#if BITS_PER_LONG == 32
+ inarg.flags |= FUSE_IOCTL_32BIT;
+#else
+ if (flags & FUSE_IOCTL_COMPAT)
+ inarg.flags |= FUSE_IOCTL_32BIT;
+#endif
+
+ /* assume all the iovs returned by client always fits in a page */
+ BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
+
+ err = -ENOMEM;
+ pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
+ iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
+ if (!pages || !iov_page)
+ goto out;
+
+ /*
+ * If restricted, initialize IO parameters as encoded in @cmd.
+ * RETRY from server is not allowed.
+ */
+ if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
+ struct iovec *iov = iov_page;
+
+ iov->iov_base = (void __user *)arg;
+ iov->iov_len = _IOC_SIZE(cmd);
+
+ if (_IOC_DIR(cmd) & _IOC_WRITE) {
+ in_iov = iov;
+ in_iovs = 1;
+ }
+
+ if (_IOC_DIR(cmd) & _IOC_READ) {
+ out_iov = iov;
+ out_iovs = 1;
+ }
+ }
+
+ retry:
+ inarg.in_size = in_size = iov_length(in_iov, in_iovs);
+ inarg.out_size = out_size = iov_length(out_iov, out_iovs);
+
+ /*
+ * Out data can be used either for actual out data or iovs,
+ * make sure there always is at least one page.
+ */
+ out_size = max_t(size_t, out_size, PAGE_SIZE);
+ max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
+
+ /* make sure there are enough buffer pages and init request with them */
+ err = -ENOMEM;
+ if (max_pages > FUSE_MAX_PAGES_PER_REQ)
+ goto out;
+ while (num_pages < max_pages) {
+ pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+ if (!pages[num_pages])
+ goto out;
+ num_pages++;
+ }
+
+ req = fuse_get_req(fc, num_pages);
+ if (IS_ERR(req)) {
+ err = PTR_ERR(req);
+ req = NULL;
+ goto out;
+ }
+ memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
+ req->num_pages = num_pages;
+ fuse_page_descs_length_init(req, 0, req->num_pages);
+
+ /* okay, let's send it to the client */
+ req->in.h.opcode = FUSE_IOCTL;
+ req->in.h.nodeid = ff->nodeid;
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(inarg);
+ req->in.args[0].value = &inarg;
+ if (in_size) {
+ req->in.numargs++;
+ req->in.args[1].size = in_size;
+ req->in.argpages = 1;
+
+ err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
+ false);
+ if (err)
+ goto out;
+ }
+
+ req->out.numargs = 2;
+ req->out.args[0].size = sizeof(outarg);
+ req->out.args[0].value = &outarg;
+ req->out.args[1].size = out_size;
+ req->out.argpages = 1;
+ req->out.argvar = 1;
+
+ fuse_request_send(fc, req);
+ err = req->out.h.error;
+ transferred = req->out.args[1].size;
+ fuse_put_request(fc, req);
+ req = NULL;
+ if (err)
+ goto out;
+
+ /* did it ask for retry? */
+ if (outarg.flags & FUSE_IOCTL_RETRY) {
+ void *vaddr;
+
+ /* no retry if in restricted mode */
+ err = -EIO;
+ if (!(flags & FUSE_IOCTL_UNRESTRICTED))
+ goto out;
+
+ in_iovs = outarg.in_iovs;
+ out_iovs = outarg.out_iovs;
+
+ /*
+ * Make sure things are in boundary, separate checks
+ * are to protect against overflow.
+ */
+ err = -ENOMEM;
+ if (in_iovs > FUSE_IOCTL_MAX_IOV ||
+ out_iovs > FUSE_IOCTL_MAX_IOV ||
+ in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
+ goto out;
+
+ vaddr = kmap_atomic(pages[0]);
+ err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
+ transferred, in_iovs + out_iovs,
+ (flags & FUSE_IOCTL_COMPAT) != 0);
+ kunmap_atomic(vaddr);
+ if (err)
+ goto out;
+
+ in_iov = iov_page;
+ out_iov = in_iov + in_iovs;
+
+ err = fuse_verify_ioctl_iov(in_iov, in_iovs);
+ if (err)
+ goto out;
+
+ err = fuse_verify_ioctl_iov(out_iov, out_iovs);
+ if (err)
+ goto out;
+
+ goto retry;
+ }
+
+ err = -EIO;
+ if (transferred > inarg.out_size)
+ goto out;
+
+ err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
+ out:
+ if (req)
+ fuse_put_request(fc, req);
+ free_page((unsigned long) iov_page);
+ while (num_pages)
+ __free_page(pages[--num_pages]);
+ kfree(pages);
+
+ return err ? err : outarg.result;
+}
+EXPORT_SYMBOL_GPL(fuse_do_ioctl);
+
+long fuse_ioctl_common(struct file *file, unsigned int cmd,
+ unsigned long arg, unsigned int flags)
+{
+ struct inode *inode = file_inode(file);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (!fuse_allow_current_process(fc))
+ return -EACCES;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ return fuse_do_ioctl(file, cmd, arg, flags);
+}
+
+static long fuse_file_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return fuse_ioctl_common(file, cmd, arg, 0);
+}
+
+static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
+}
+
+/*
+ * All files which have been polled are linked to RB tree
+ * fuse_conn->polled_files which is indexed by kh. Walk the tree and
+ * find the matching one.
+ */
+static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
+ struct rb_node **parent_out)
+{
+ struct rb_node **link = &fc->polled_files.rb_node;
+ struct rb_node *last = NULL;
+
+ while (*link) {
+ struct fuse_file *ff;
+
+ last = *link;
+ ff = rb_entry(last, struct fuse_file, polled_node);
+
+ if (kh < ff->kh)
+ link = &last->rb_left;
+ else if (kh > ff->kh)
+ link = &last->rb_right;
+ else
+ return link;
+ }
+
+ if (parent_out)
+ *parent_out = last;
+ return link;
+}
+
+/*
+ * The file is about to be polled. Make sure it's on the polled_files
+ * RB tree. Note that files once added to the polled_files tree are
+ * not removed before the file is released. This is because a file
+ * polled once is likely to be polled again.
+ */
+static void fuse_register_polled_file(struct fuse_conn *fc,
+ struct fuse_file *ff)
+{
+ spin_lock(&fc->lock);
+ if (RB_EMPTY_NODE(&ff->polled_node)) {
+ struct rb_node **link, *uninitialized_var(parent);
+
+ link = fuse_find_polled_node(fc, ff->kh, &parent);
+ BUG_ON(*link);
+ rb_link_node(&ff->polled_node, parent, link);
+ rb_insert_color(&ff->polled_node, &fc->polled_files);
+ }
+ spin_unlock(&fc->lock);
+}
+
+unsigned fuse_file_poll(struct file *file, poll_table *wait)
+{
+ struct fuse_file *ff = file->private_data;
+ struct fuse_conn *fc = ff->fc;
+ struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
+ struct fuse_poll_out outarg;
+ FUSE_ARGS(args);
+ int err;
+
+ if (fc->no_poll)
+ return DEFAULT_POLLMASK;
+
+ poll_wait(file, &ff->poll_wait, wait);
+ inarg.events = (__u32)poll_requested_events(wait);
+
+ /*
+ * Ask for notification iff there's someone waiting for it.
+ * The client may ignore the flag and always notify.
+ */
+ if (waitqueue_active(&ff->poll_wait)) {
+ inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
+ fuse_register_polled_file(fc, ff);
+ }
+
+ args.in.h.opcode = FUSE_POLL;
+ args.in.h.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 outarg.revents;
+ if (err == -ENOSYS) {
+ fc->no_poll = 1;
+ return DEFAULT_POLLMASK;
+ }
+ return POLLERR;
+}
+EXPORT_SYMBOL_GPL(fuse_file_poll);
+
+/*
+ * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
+ * wakes up the poll waiters.
+ */
+int fuse_notify_poll_wakeup(struct fuse_conn *fc,
+ struct fuse_notify_poll_wakeup_out *outarg)
+{
+ u64 kh = outarg->kh;
+ struct rb_node **link;
+
+ spin_lock(&fc->lock);
+
+ link = fuse_find_polled_node(fc, kh, NULL);
+ if (*link) {
+ struct fuse_file *ff;
+
+ ff = rb_entry(*link, struct fuse_file, polled_node);
+ wake_up_interruptible_sync(&ff->poll_wait);
+ }
+
+ spin_unlock(&fc->lock);
+ return 0;
+}
+
+static void fuse_do_truncate(struct file *file)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct iattr attr;
+
+ attr.ia_valid = ATTR_SIZE;
+ attr.ia_size = i_size_read(inode);
+
+ attr.ia_file = file;
+ attr.ia_valid |= ATTR_FILE;
+
+ fuse_do_setattr(inode, &attr, file);
+}
+
+static inline loff_t fuse_round_up(loff_t off)
+{
+ return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
+}
+
+static ssize_t
+fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ ssize_t ret = 0;
+ struct file *file = iocb->ki_filp;
+ struct fuse_file *ff = file->private_data;
+ bool async_dio = ff->fc->async_dio;
+ loff_t pos = 0;
+ struct inode *inode;
+ loff_t i_size;
+ size_t count = iov_iter_count(iter);
+ 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;
+
+ /* optimization for short read */
+ if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) {
+ if (offset >= i_size)
+ return 0;
+ iov_iter_truncate(iter, fuse_round_up(i_size - offset));
+ count = iov_iter_count(iter);
+ }
+
+ io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
+ if (!io)
+ return -ENOMEM;
+ spin_lock_init(&io->lock);
+ io->reqs = 1;
+ io->bytes = -1;
+ io->size = 0;
+ io->offset = offset;
+ io->write = (iov_iter_rw(iter) == WRITE);
+ io->err = 0;
+ io->file = file;
+ /*
+ * By default, we want to optimize all I/Os with async request
+ * submission to the client filesystem if supported.
+ */
+ io->async = async_dio;
+ io->iocb = iocb;
+
+ /*
+ * We cannot asynchronously extend the size of a file. We have no method
+ * to wait on real async I/O requests, so we must submit this request
+ * synchronously.
+ */
+ if (!is_sync_kiocb(iocb) && (offset + count > i_size) &&
+ iov_iter_rw(iter) == WRITE)
+ io->async = false;
+
+ if (io->async && is_sync_kiocb(iocb))
+ 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);
+ }
+
+ if (io->async) {
+ fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
+
+ /* we have a non-extending, async request, so return */
+ if (!is_sync_kiocb(iocb))
+ return -EIOCBQUEUED;
+
+ wait_for_completion(&wait);
+ ret = fuse_get_res_by_io(io);
+ }
+
+ kfree(io);
+
+ 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 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) {
+ mutex_lock(&inode->i_mutex);
+ if (mode & FALLOC_FL_PUNCH_HOLE) {
+ loff_t endbyte = offset + length - 1;
+ err = filemap_write_and_wait_range(inode->i_mapping,
+ offset, endbyte);
+ if (err)
+ goto out;
+
+ fuse_sync_writes(inode);
+ }
+ }
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE))
+ set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+
+ args.in.h.opcode = FUSE_FALLOCATE;
+ args.in.h.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)
+ mutex_unlock(&inode->i_mutex);
+
+ return err;
+}
+
+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,
+ .unlocked_ioctl = fuse_file_ioctl,
+ .compat_ioctl = fuse_file_compat_ioctl,
+ .poll = fuse_file_poll,
+ .fallocate = fuse_file_fallocate,
+};
+
+static const struct file_operations fuse_direct_io_file_operations = {
+ .llseek = fuse_file_llseek,
+ .read_iter = fuse_direct_read_iter,
+ .write_iter = fuse_direct_write_iter,
+ .mmap = fuse_direct_mmap,
+ .open = fuse_open,
+ .flush = fuse_flush,
+ .release = fuse_release,
+ .fsync = fuse_fsync,
+ .lock = fuse_file_lock,
+ .flock = fuse_file_flock,
+ .unlocked_ioctl = fuse_file_ioctl,
+ .compat_ioctl = fuse_file_compat_ioctl,
+ .poll = fuse_file_poll,
+ .fallocate = fuse_file_fallocate,
+ /* no splice_read */
+};
+
+static const struct address_space_operations fuse_file_aops = {
+ .readpage = fuse_readpage,
+ .writepage = fuse_writepage,
+ .writepages = fuse_writepages,
+ .launder_page = fuse_launder_page,
+ .readpages = fuse_readpages,
+ .set_page_dirty = __set_page_dirty_nobuffers,
+ .bmap = fuse_bmap,
+ .direct_IO = fuse_direct_IO,
+ .write_begin = fuse_write_begin,
+ .write_end = fuse_write_end,
+};
+
+void fuse_init_file_inode(struct inode *inode)
+{
+ inode->i_fop = &fuse_file_operations;
+ inode->i_data.a_ops = &fuse_file_aops;
+}
Code Review / kvmfornfv.git / blobdiff