X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Ffuse%2Ffile.c;h=0946861b10b7eabe917670c127ec922b69cc5688;hb=ce60a2f15764f296b0467960759351702c7d2986;hp=c4c59c7d0038cfc2ecfa50ca3d8d33f4cb6dbd94;hpb=93a8c3cd9e9834dc5f5c373336f3a0065521152d;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c4c59c7..0946861 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1,6 +1,6 @@
 /*
   FUSE: Filesystem in Userspace
-  Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
+  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
 
   This program can be distributed under the terms of the GNU GPL.
   See the file COPYING.
@@ -39,14 +39,14 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
 	req->out.numargs = 1;
 	req->out.args[0].size = sizeof(*outargp);
 	req->out.args[0].value = outargp;
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 
 	return err;
 }
 
-struct fuse_file *fuse_file_alloc(void)
+struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
 {
 	struct fuse_file *ff;
 	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
@@ -54,10 +54,16 @@ struct fuse_file *fuse_file_alloc(void)
 		ff->reserved_req = fuse_request_alloc();
 		if (!ff->reserved_req) {
 			kfree(ff);
-			ff = NULL;
+			return NULL;
+		} else {
+			INIT_LIST_HEAD(&ff->write_entry);
+			atomic_set(&ff->count, 0);
+			spin_lock(&fc->lock);
+			ff->kh = ++fc->khctr;
+			spin_unlock(&fc->lock);
 		}
-		INIT_LIST_HEAD(&ff->write_entry);
-		atomic_set(&ff->count, 0);
+		RB_CLEAR_NODE(&ff->polled_node);
+		init_waitqueue_head(&ff->poll_wait);
 	}
 	return ff;
 }
@@ -76,18 +82,18 @@ static struct fuse_file *fuse_file_get(struct fuse_file *ff)
 
 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
 {
-	dput(req->dentry);
-	mntput(req->vfsmount);
-	fuse_put_request(fc, req);
+	dput(req->misc.release.dentry);
+	mntput(req->misc.release.vfsmount);
 }
 
 static void fuse_file_put(struct fuse_file *ff)
 {
 	if (atomic_dec_and_test(&ff->count)) {
 		struct fuse_req *req = ff->reserved_req;
-		struct fuse_conn *fc = get_fuse_conn(req->dentry->d_inode);
+		struct inode *inode = req->misc.release.dentry->d_inode;
+		struct fuse_conn *fc = get_fuse_conn(inode);
 		req->end = fuse_release_end;
-		request_send_background(fc, req);
+		fuse_request_send_background(fc, req);
 		kfree(ff);
 	}
 }
@@ -99,12 +105,15 @@ void fuse_finish_open(struct inode *inode, struct file *file,
 		file->f_op = &fuse_direct_io_file_operations;
 	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
 		invalidate_inode_pages2(inode->i_mapping);
+	if (outarg->open_flags & FOPEN_NONSEEKABLE)
+		nonseekable_open(inode, file);
 	ff->fh = outarg->fh;
 	file->private_data = fuse_file_get(ff);
 }
 
 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 {
+	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_open_out outarg;
 	struct fuse_file *ff;
 	int err;
@@ -117,7 +126,7 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 	if (err)
 		return err;
 
-	ff = fuse_file_alloc();
+	ff = fuse_file_alloc(fc);
 	if (!ff)
 		return -ENOMEM;
 
@@ -136,7 +145,7 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
 {
 	struct fuse_req *req = ff->reserved_req;
-	struct fuse_release_in *inarg = &req->misc.release_in;
+	struct fuse_release_in *inarg = &req->misc.release.in;
 
 	inarg->fh = ff->fh;
 	inarg->flags = flags;
@@ -152,17 +161,22 @@ int fuse_release_common(struct inode *inode, struct file *file, int isdir)
 	struct fuse_file *ff = file->private_data;
 	if (ff) {
 		struct fuse_conn *fc = get_fuse_conn(inode);
+		struct fuse_req *req = ff->reserved_req;
 
 		fuse_release_fill(ff, get_node_id(inode), file->f_flags,
 				  isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
 
 		/* Hold vfsmount and dentry until release is finished */
-		ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
-		ff->reserved_req->dentry = dget(file->f_path.dentry);
+		req->misc.release.vfsmount = mntget(file->f_path.mnt);
+		req->misc.release.dentry = dget(file->f_path.dentry);
 
 		spin_lock(&fc->lock);
 		list_del(&ff->write_entry);
+		if (!RB_EMPTY_NODE(&ff->polled_node))
+			rb_erase(&ff->polled_node, &fc->polled_files);
 		spin_unlock(&fc->lock);
+
+		wake_up_interruptible_sync(&ff->poll_wait);
 		/*
 		 * Normally this will send the RELEASE request,
 		 * however if some asynchronous READ or WRITE requests
@@ -189,7 +203,7 @@ static int fuse_release(struct inode *inode, struct file *file)
  * Scramble the ID space with XTEA, so that the value of the files_struct
  * pointer is not exposed to userspace.
  */
-static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
+u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
 {
 	u32 *k = fc->scramble_key;
 	u64 v = (unsigned long) id;
@@ -207,6 +221,49 @@ static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
 	return (u64) v0 + ((u64) v1 << 32);
 }
 
+/*
+ * Check if page is under writeback
+ *
+ * This is currently done by walking the list of writepage requests
+ * for the inode, which can be pretty inefficient.
+ */
+static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_inode *fi = get_fuse_inode(inode);
+	struct fuse_req *req;
+	bool found = false;
+
+	spin_lock(&fc->lock);
+	list_for_each_entry(req, &fi->writepages, writepages_entry) {
+		pgoff_t curr_index;
+
+		BUG_ON(req->inode != inode);
+		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+		if (curr_index == index) {
+			found = true;
+			break;
+		}
+	}
+	spin_unlock(&fc->lock);
+
+	return found;
+}
+
+/*
+ * Wait for page writeback to be completed.
+ *
+ * Since fuse doesn't rely on the VM writeback tracking, this has to
+ * use some other means.
+ */
+static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
+{
+	struct fuse_inode *fi = get_fuse_inode(inode);
+
+	wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
+	return 0;
+}
+
 static int fuse_flush(struct file *file, fl_owner_t id)
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
@@ -232,7 +289,7 @@ static int fuse_flush(struct file *file, fl_owner_t id)
 	req->in.args[0].size = sizeof(inarg);
 	req->in.args[0].value = &inarg;
 	req->force = 1;
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (err == -ENOSYS) {
@@ -242,6 +299,21 @@ static int fuse_flush(struct file *file, fl_owner_t id)
 	return err;
 }
 
+/*
+ * Wait for all pending writepages on the inode to finish.
+ *
+ * This is currently done by blocking further writes with FUSE_NOWRITE
+ * and waiting for all sent writes to complete.
+ *
+ * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
+ * could conflict with truncation.
+ */
+static void fuse_sync_writes(struct inode *inode)
+{
+	fuse_set_nowrite(inode);
+	fuse_release_nowrite(inode);
+}
+
 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 		      int isdir)
 {
@@ -258,6 +330,17 @@ int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
 		return 0;
 
+	/*
+	 * Start writeback against all dirty pages of the inode, then
+	 * wait for all outstanding writes, before sending the FSYNC
+	 * request.
+	 */
+	err = write_inode_now(inode, 0);
+	if (err)
+		return err;
+
+	fuse_sync_writes(inode);
+
 	req = fuse_get_req(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -270,7 +353,7 @@ int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(inarg);
 	req->in.args[0].value = &inarg;
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (err == -ENOSYS) {
@@ -288,59 +371,104 @@ static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
 	return fuse_fsync_common(file, de, datasync, 0);
 }
 
-void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff,
+void fuse_read_fill(struct fuse_req *req, struct file *file,
 		    struct inode *inode, loff_t pos, size_t count, int opcode)
 {
-	struct fuse_read_in *inarg = &req->misc.read_in;
+	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 = get_node_id(inode);
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(struct fuse_read_in);
 	req->in.args[0].value = inarg;
-	req->out.argpages = 1;
 	req->out.argvar = 1;
 	req->out.numargs = 1;
 	req->out.args[0].size = count;
 }
 
 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
-			     struct inode *inode, loff_t pos, size_t count)
+			     struct inode *inode, loff_t pos, size_t count,
+			     fl_owner_t owner)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_file *ff = file->private_data;
-	fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
-	request_send(fc, req);
+
+	fuse_read_fill(req, file, inode, 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);
+	}
+	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) {
+		fi->attr_version = ++fc->attr_version;
+		i_size_write(inode, size);
+	}
+	spin_unlock(&fc->lock);
+}
+
 static int fuse_readpage(struct file *file, struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
+	size_t num_read;
+	loff_t pos = page_offset(page);
+	size_t count = PAGE_CACHE_SIZE;
+	u64 attr_ver;
 	int err;
 
 	err = -EIO;
 	if (is_bad_inode(inode))
 		goto out;
 
+	/*
+	 * Page writeback can extend beyond the liftime 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);
 	err = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out;
 
+	attr_ver = fuse_get_attr_version(fc);
+
 	req->out.page_zeroing = 1;
+	req->out.argpages = 1;
 	req->num_pages = 1;
 	req->pages[0] = page;
-	fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
+	num_read = fuse_send_read(req, file, inode, pos, count, NULL);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
-	if (!err)
+
+	if (!err) {
+		/*
+		 * Short read means EOF.  If file size is larger, truncate it
+		 */
+		if (num_read < count)
+			fuse_read_update_size(inode, pos + num_read, attr_ver);
+
 		SetPageUptodate(page);
+	}
+
 	fuse_invalidate_attr(inode); /* atime changed */
  out:
 	unlock_page(page);
@@ -350,8 +478,19 @@ static int fuse_readpage(struct file *file, struct page *page)
 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 inode *inode = req->pages[0]->mapping->host;
+
+	/*
+	 * Short read means EOF.  If file size is larger, truncate it
+	 */
+	if (!req->out.h.error && num_read < count) {
+		loff_t pos = page_offset(req->pages[0]) + num_read;
+		fuse_read_update_size(inode, pos, req->misc.read.attr_ver);
+	}
 
-	fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
+	fuse_invalidate_attr(inode); /* atime changed */
 
 	for (i = 0; i < req->num_pages; i++) {
 		struct page *page = req->pages[i];
@@ -363,30 +502,34 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
 	}
 	if (req->ff)
 		fuse_file_put(req->ff);
-	fuse_put_request(fc, req);
 }
 
-static void fuse_send_readpages(struct fuse_req *req, struct fuse_file *ff,
+static void fuse_send_readpages(struct fuse_req *req, struct file *file,
 				struct inode *inode)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	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;
-	fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
+	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
+	req->misc.read.attr_ver = fuse_get_attr_version(fc);
 	if (fc->async_read) {
+		struct fuse_file *ff = file->private_data;
 		req->ff = fuse_file_get(ff);
 		req->end = fuse_readpages_end;
-		request_send_background(fc, req);
+		fuse_request_send_background(fc, req);
 	} else {
-		request_send(fc, req);
+		fuse_request_send(fc, req);
 		fuse_readpages_end(fc, req);
+		fuse_put_request(fc, req);
 	}
 }
 
 struct fuse_fill_data {
 	struct fuse_req *req;
-	struct fuse_file *ff;
+	struct file *file;
 	struct inode *inode;
 };
 
@@ -397,11 +540,13 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 	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)) {
-		fuse_send_readpages(req, data->ff, inode);
+		fuse_send_readpages(req, data->file, inode);
 		data->req = req = fuse_get_req(fc);
 		if (IS_ERR(req)) {
 			unlock_page(page);
@@ -409,7 +554,7 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 		}
 	}
 	req->pages[req->num_pages] = page;
-	req->num_pages ++;
+	req->num_pages++;
 	return 0;
 }
 
@@ -425,7 +570,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
 	if (is_bad_inode(inode))
 		goto out;
 
-	data.ff = file->private_data;
+	data.file = file;
 	data.inode = inode;
 	data.req = fuse_get_req(fc);
 	err = PTR_ERR(data.req);
@@ -435,7 +580,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
 	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
 	if (!err) {
 		if (data.req->num_pages)
-			fuse_send_readpages(data.req, data.ff, inode);
+			fuse_send_readpages(data.req, file, inode);
 		else
 			fuse_put_request(fc, data.req);
 	}
@@ -443,30 +588,66 @@ out:
 	return err;
 }
 
-static size_t fuse_send_write(struct fuse_req *req, struct file *file,
-			      struct inode *inode, loff_t pos, size_t count)
+static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+				  unsigned long nr_segs, loff_t pos)
+{
+	struct inode *inode = iocb->ki_filp->f_mapping->host;
+
+	if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
+		int err;
+		/*
+		 * If trying to read past EOF, make sure the i_size
+		 * attribute is up-to-date.
+		 */
+		err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
+		if (err)
+			return err;
+	}
+
+	return generic_file_aio_read(iocb, iov, nr_segs, pos);
+}
+
+static void fuse_write_fill(struct fuse_req *req, struct file *file,
+			    struct fuse_file *ff, struct inode *inode,
+			    loff_t pos, size_t count, int writepage)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_file *ff = file->private_data;
-	struct fuse_write_in inarg;
-	struct fuse_write_out outarg;
+	struct fuse_write_in *inarg = &req->misc.write.in;
+	struct fuse_write_out *outarg = &req->misc.write.out;
 
-	memset(&inarg, 0, sizeof(struct fuse_write_in));
-	inarg.fh = ff->fh;
-	inarg.offset = pos;
-	inarg.size = count;
+	memset(inarg, 0, sizeof(struct fuse_write_in));
+	inarg->fh = ff->fh;
+	inarg->offset = pos;
+	inarg->size = count;
+	inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
+	inarg->flags = file ? file->f_flags : 0;
 	req->in.h.opcode = FUSE_WRITE;
 	req->in.h.nodeid = get_node_id(inode);
-	req->in.argpages = 1;
 	req->in.numargs = 2;
-	req->in.args[0].size = sizeof(struct fuse_write_in);
-	req->in.args[0].value = &inarg;
+	if (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;
-	request_send(fc, req);
-	return outarg.size;
+	req->out.args[0].value = outarg;
+}
+
+static size_t fuse_send_write(struct fuse_req *req, struct file *file,
+			      struct inode *inode, loff_t pos, size_t count,
+			      fl_owner_t owner)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	fuse_write_fill(req, file, file->private_data, inode, pos, count, 0);
+	if (owner != NULL) {
+		struct fuse_write_in *inarg = &req->misc.write.in;
+		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
+		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+	}
+	fuse_request_send(fc, req);
+	return req->misc.write.out.size;
 }
 
 static int fuse_write_begin(struct file *file, struct address_space *mapping,
@@ -475,45 +656,58 @@ static int fuse_write_begin(struct file *file, struct address_space *mapping,
 {
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 
-	*pagep = __grab_cache_page(mapping, index);
+	*pagep = grab_cache_page_write_begin(mapping, index, flags);
 	if (!*pagep)
 		return -ENOMEM;
 	return 0;
 }
 
+static void fuse_write_update_size(struct inode *inode, loff_t pos)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_inode *fi = get_fuse_inode(inode);
+
+	spin_lock(&fc->lock);
+	fi->attr_version = ++fc->attr_version;
+	if (pos > inode->i_size)
+		i_size_write(inode, pos);
+	spin_unlock(&fc->lock);
+}
+
 static int fuse_buffered_write(struct file *file, struct inode *inode,
 			       loff_t pos, unsigned count, struct page *page)
 {
 	int err;
 	size_t nres;
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_inode *fi = get_fuse_inode(inode);
 	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 	struct fuse_req *req;
 
 	if (is_bad_inode(inode))
 		return -EIO;
 
+	/*
+	 * Make sure writepages on the same page are not mixed up with
+	 * plain writes.
+	 */
+	fuse_wait_on_page_writeback(inode, page->index);
+
 	req = fuse_get_req(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
+	req->in.argpages = 1;
 	req->num_pages = 1;
 	req->pages[0] = page;
 	req->page_offset = offset;
-	nres = fuse_send_write(req, file, inode, pos, count);
+	nres = fuse_send_write(req, file, inode, pos, count, NULL);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (!err && !nres)
 		err = -EIO;
 	if (!err) {
 		pos += nres;
-		spin_lock(&fc->lock);
-		fi->attr_version = ++fc->attr_version;
-		if (pos > inode->i_size)
-			i_size_write(inode, pos);
-		spin_unlock(&fc->lock);
-
+		fuse_write_update_size(inode, pos);
 		if (count == PAGE_CACHE_SIZE)
 			SetPageUptodate(page);
 	}
@@ -536,6 +730,201 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
 	return res;
 }
 
+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;
+
+	for (i = 0; i < req->num_pages; i++)
+		fuse_wait_on_page_writeback(inode, req->pages[i]->index);
+
+	res = fuse_send_write(req, file, inode, pos, count, NULL);
+
+	offset = req->page_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_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;
+
+		pagefault_disable();
+		tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
+		pagefault_enable();
+		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->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 < FUSE_MAX_PAGES_PER_REQ && offset == 0);
+
+	return count > 0 ? count : err;
+}
+
+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);
+	int err = 0;
+	ssize_t res = 0;
+
+	if (is_bad_inode(inode))
+		return -EIO;
+
+	do {
+		struct fuse_req *req;
+		ssize_t count;
+
+		req = fuse_get_req(fc);
+		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);
+
+	fuse_invalidate_attr(inode);
+
+	return res > 0 ? res : err;
+}
+
+static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+				   unsigned long nr_segs, loff_t pos)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	size_t count = 0;
+	ssize_t written = 0;
+	struct inode *inode = mapping->host;
+	ssize_t err;
+	struct iov_iter i;
+
+	WARN_ON(iocb->ki_pos != pos);
+
+	err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
+	if (err)
+		return err;
+
+	mutex_lock(&inode->i_mutex);
+	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
+	/* We can write back this queue in page reclaim */
+	current->backing_dev_info = mapping->backing_dev_info;
+
+	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+	if (err)
+		goto out;
+
+	if (count == 0)
+		goto out;
+
+	err = file_remove_suid(file);
+	if (err)
+		goto out;
+
+	file_update_time(file);
+
+	iov_iter_init(&i, iov, nr_segs, count, 0);
+	written = fuse_perform_write(file, mapping, &i, pos);
+	if (written >= 0)
+		iocb->ki_pos = pos + written;
+
+out:
+	current->backing_dev_info = NULL;
+	mutex_unlock(&inode->i_mutex);
+
+	return written ? written : err;
+}
+
 static void fuse_release_user_pages(struct fuse_req *req, int write)
 {
 	unsigned i;
@@ -549,21 +938,28 @@ static void fuse_release_user_pages(struct fuse_req *req, int write)
 }
 
 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
-			       unsigned nbytes, int write)
+			       size_t *nbytesp, int write)
 {
+	size_t nbytes = *nbytesp;
 	unsigned long user_addr = (unsigned long) buf;
 	unsigned offset = user_addr & ~PAGE_MASK;
 	int npages;
 
-	/* This doesn't work with nfsd */
-	if (!current->mm)
-		return -EPERM;
+	/* Special case for kernel I/O: can copy directly into the buffer */
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		if (write)
+			req->in.args[1].value = (void *) user_addr;
+		else
+			req->out.args[0].value = (void *) user_addr;
 
-	nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
+		return 0;
+	}
+
+	nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
 	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
+	npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
 	down_read(&current->mm->mmap_sem);
-	npages = get_user_pages(current, current->mm, user_addr, npages, write,
+	npages = get_user_pages(current, current->mm, user_addr, npages, !write,
 				0, req->pages, NULL);
 	up_read(&current->mm->mmap_sem);
 	if (npages < 0)
@@ -571,6 +967,15 @@ static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
 
 	req->num_pages = npages;
 	req->page_offset = offset;
+
+	if (write)
+		req->in.argpages = 1;
+	else
+		req->out.argpages = 1;
+
+	nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
+	*nbytesp = min(*nbytesp, nbytes);
+
 	return 0;
 }
 
@@ -594,17 +999,18 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 	while (count) {
 		size_t nres;
 		size_t nbytes = min(count, nmax);
-		int err = fuse_get_user_pages(req, buf, nbytes, !write);
+		int err = fuse_get_user_pages(req, buf, &nbytes, write);
 		if (err) {
 			res = err;
 			break;
 		}
-		nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
-		nbytes = min(count, nbytes);
+
 		if (write)
-			nres = fuse_send_write(req, file, inode, pos, nbytes);
+			nres = fuse_send_write(req, file, inode, pos, nbytes,
+					       current->files);
 		else
-			nres = fuse_send_read(req, file, inode, pos, nbytes);
+			nres = fuse_send_read(req, file, inode, pos, nbytes,
+					      current->files);
 		fuse_release_user_pages(req, !write);
 		if (req->out.h.error) {
 			if (!res)
@@ -629,12 +1035,8 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 	}
 	fuse_put_request(fc, req);
 	if (res > 0) {
-		if (write) {
-			spin_lock(&fc->lock);
-			if (pos > inode->i_size)
-				i_size_write(inode, pos);
-			spin_unlock(&fc->lock);
-		}
+		if (write)
+			fuse_write_update_size(inode, pos);
 		*ppos = pos;
 	}
 	fuse_invalidate_attr(inode);
@@ -662,24 +1064,243 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 	return res;
 }
 
-static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
+static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
 {
-	if ((vma->vm_flags & VM_SHARED)) {
-		if ((vma->vm_flags & VM_WRITE))
-			return -ENODEV;
-		else
-			vma->vm_flags &= ~VM_MAYWRITE;
+	__free_page(req->pages[0]);
+	fuse_file_put(req->ff);
+}
+
+static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
+{
+	struct inode *inode = req->inode;
+	struct fuse_inode *fi = get_fuse_inode(inode);
+	struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
+
+	list_del(&req->writepages_entry);
+	dec_bdi_stat(bdi, BDI_WRITEBACK);
+	dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
+	bdi_writeout_inc(bdi);
+	wake_up(&fi->page_waitq);
+}
+
+/* Called under fc->lock, may release and reacquire it */
+static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
+__releases(&fc->lock)
+__acquires(&fc->lock)
+{
+	struct fuse_inode *fi = get_fuse_inode(req->inode);
+	loff_t size = i_size_read(req->inode);
+	struct fuse_write_in *inarg = &req->misc.write.in;
+
+	if (!fc->connected)
+		goto out_free;
+
+	if (inarg->offset + PAGE_CACHE_SIZE <= size) {
+		inarg->size = PAGE_CACHE_SIZE;
+	} else if (inarg->offset < size) {
+		inarg->size = size & (PAGE_CACHE_SIZE - 1);
+	} else {
+		/* Got truncated off completely */
+		goto out_free;
 	}
-	return generic_file_mmap(file, vma);
+
+	req->in.args[1].size = inarg->size;
+	fi->writectr++;
+	fuse_request_send_background_locked(fc, req);
+	return;
+
+ out_free:
+	fuse_writepage_finish(fc, req);
+	spin_unlock(&fc->lock);
+	fuse_writepage_free(fc, req);
+	fuse_put_request(fc, req);
+	spin_lock(&fc->lock);
+}
+
+/*
+ * If fi->writectr is positive (no truncate or fsync going on) send
+ * all queued writepage requests.
+ *
+ * Called with fc->lock
+ */
+void fuse_flush_writepages(struct inode *inode)
+__releases(&fc->lock)
+__acquires(&fc->lock)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_inode *fi = get_fuse_inode(inode);
+	struct fuse_req *req;
+
+	while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
+		req = list_entry(fi->queued_writes.next, struct fuse_req, list);
+		list_del_init(&req->list);
+		fuse_send_writepage(fc, req);
+	}
+}
+
+static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
+{
+	struct inode *inode = req->inode;
+	struct fuse_inode *fi = get_fuse_inode(inode);
+
+	mapping_set_error(inode->i_mapping, req->out.h.error);
+	spin_lock(&fc->lock);
+	fi->writectr--;
+	fuse_writepage_finish(fc, req);
+	spin_unlock(&fc->lock);
+	fuse_writepage_free(fc, req);
+}
+
+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 fuse_file *ff;
+	struct page *tmp_page;
+
+	set_page_writeback(page);
+
+	req = fuse_request_alloc_nofs();
+	if (!req)
+		goto err;
+
+	tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+	if (!tmp_page)
+		goto err_free;
+
+	spin_lock(&fc->lock);
+	BUG_ON(list_empty(&fi->write_files));
+	ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
+	req->ff = fuse_file_get(ff);
+	spin_unlock(&fc->lock);
+
+	fuse_write_fill(req, NULL, ff, inode, page_offset(page), 0, 1);
+
+	copy_highpage(tmp_page, page);
+	req->in.argpages = 1;
+	req->num_pages = 1;
+	req->pages[0] = tmp_page;
+	req->page_offset = 0;
+	req->end = fuse_writepage_end;
+	req->inode = inode;
+
+	inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
+	inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
+	end_page_writeback(page);
+
+	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);
+
+	return 0;
+
+err_free:
+	fuse_request_free(req);
+err:
+	end_page_writeback(page);
+	return -ENOMEM;
 }
 
-static int fuse_set_page_dirty(struct page *page)
+static int fuse_writepage(struct page *page, struct writeback_control *wbc)
 {
-	printk("fuse_set_page_dirty: should not happen\n");
-	dump_stack();
+	int err;
+
+	err = fuse_writepage_locked(page);
+	unlock_page(page);
+
+	return err;
+}
+
+static int fuse_launder_page(struct page *page)
+{
+	int err = 0;
+	if (clear_page_dirty_for_io(page)) {
+		struct inode *inode = page->mapping->host;
+		err = fuse_writepage_locked(page);
+		if (!err)
+			fuse_wait_on_page_writeback(inode, page->index);
+	}
+	return err;
+}
+
+/*
+ * Write back dirty pages now, because there may not be any suitable
+ * open files later
+ */
+static void fuse_vma_close(struct vm_area_struct *vma)
+{
+	filemap_write_and_wait(vma->vm_file->f_mapping);
+}
+
+/*
+ * Wait for writeback against this page to complete before allowing it
+ * to be marked dirty again, and hence written back again, possibly
+ * before the previous writepage completed.
+ *
+ * Block here, instead of in ->writepage(), so that the userspace fs
+ * can only block processes actually operating on the filesystem.
+ *
+ * Otherwise unprivileged userspace fs would be able to block
+ * unrelated:
+ *
+ * - page migration
+ * - sync(2)
+ * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
+ */
+static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	/*
+	 * Don't use page->mapping as it may become NULL from a
+	 * concurrent truncate.
+	 */
+	struct inode *inode = vma->vm_file->f_mapping->host;
+
+	fuse_wait_on_page_writeback(inode, page->index);
 	return 0;
 }
 
+static struct vm_operations_struct fuse_file_vm_ops = {
+	.close		= fuse_vma_close,
+	.fault		= filemap_fault,
+	.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)) {
+		struct inode *inode = file->f_dentry->d_inode;
+		struct fuse_conn *fc = get_fuse_conn(inode);
+		struct fuse_inode *fi = get_fuse_inode(inode);
+		struct fuse_file *ff = file->private_data;
+		/*
+		 * file may be written through mmap, so chain it onto the
+		 * inodes's write_file list
+		 */
+		spin_lock(&fc->lock);
+		if (list_empty(&ff->write_entry))
+			list_add(&ff->write_entry, &fi->write_files);
+		spin_unlock(&fc->lock);
+	}
+	file_accessed(file);
+	vma->vm_ops = &fuse_file_vm_ops;
+	return 0;
+}
+
+static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	/* Can't provide the coherency needed for MAP_SHARED */
+	if (vma->vm_flags & VM_MAYSHARE)
+		return -ENODEV;
+
+	return generic_file_mmap(file, vma);
+}
+
 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
 				  struct file_lock *fl)
 {
@@ -745,7 +1366,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
 	req->out.numargs = 1;
 	req->out.args[0].size = sizeof(outarg);
 	req->out.args[0].value = &outarg;
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (!err)
@@ -763,6 +1384,11 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 	pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
 	int err;
 
+	if (fl->fl_lmops && fl->fl_lmops->fl_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;
@@ -772,7 +1398,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 		return PTR_ERR(req);
 
 	fuse_lk_fill(req, file, fl, opcode, pid, flock);
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	/* locking is restartable */
 	if (err == -EINTR)
@@ -787,7 +1413,9 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	int err;
 
-	if (cmd == F_GETLK) {
+	if (cmd == F_CANCELLK) {
+		err = 0;
+	} else if (cmd == F_GETLK) {
 		if (fc->no_lock) {
 			posix_test_lock(file, fl);
 			err = 0;
@@ -795,7 +1423,7 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 			err = fuse_getlk(file, fl);
 	} else {
 		if (fc->no_lock)
-			err = posix_lock_file_wait(file, fl);
+			err = posix_lock_file(file, fl, NULL);
 		else
 			err = fuse_setlk(file, fl, 0);
 	}
@@ -846,7 +1474,7 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 	req->out.numargs = 1;
 	req->out.args[0].size = sizeof(outarg);
 	req->out.args[0].value = &outarg;
-	request_send(fc, req);
+	fuse_request_send(fc, req);
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (err == -ENOSYS)
@@ -855,12 +1483,441 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 	return err ? 0 : outarg.block;
 }
 
+static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
+{
+	loff_t retval;
+	struct inode *inode = file->f_path.dentry->d_inode;
+
+	mutex_lock(&inode->i_mutex);
+	switch (origin) {
+	case SEEK_END:
+		retval = fuse_update_attributes(inode, NULL, file, NULL);
+		if (retval)
+			goto exit;
+		offset += i_size_read(inode);
+		break;
+	case SEEK_CUR:
+		offset += file->f_pos;
+	}
+	retval = -EINVAL;
+	if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
+		if (offset != file->f_pos) {
+			file->f_pos = offset;
+			file->f_version = 0;
+		}
+		retval = offset;
+	}
+exit:
+	mutex_unlock(&inode->i_mutex);
+	return retval;
+}
+
+static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
+			unsigned int nr_segs, size_t bytes, bool to_user)
+{
+	struct iov_iter ii;
+	int page_idx = 0;
+
+	if (!bytes)
+		return 0;
+
+	iov_iter_init(&ii, iov, nr_segs, bytes, 0);
+
+	while (iov_iter_count(&ii)) {
+		struct page *page = pages[page_idx++];
+		size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
+		void *kaddr, *map;
+
+		kaddr = map = kmap(page);
+
+		while (todo) {
+			char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
+			size_t iov_len = ii.iov->iov_len - ii.iov_offset;
+			size_t copy = min(todo, iov_len);
+			size_t left;
+
+			if (!to_user)
+				left = copy_from_user(kaddr, uaddr, copy);
+			else
+				left = copy_to_user(uaddr, kaddr, copy);
+
+			if (unlikely(left))
+				return -EFAULT;
+
+			iov_iter_advance(&ii, copy);
+			todo -= copy;
+			kaddr += copy;
+		}
+
+		kunmap(map);
+	}
+
+	return 0;
+}
+
+/*
+ * For ioctls, there is no generic way to determine how much memory
+ * needs to be read and/or written.  Furthermore, ioctls are allowed
+ * to dereference the passed pointer, so the parameter requires deep
+ * copying but FUSE has no idea whatsoever about what to copy in or
+ * out.
+ *
+ * This is solved by allowing FUSE server to retry ioctl with
+ * necessary in/out iovecs.  Let's assume the ioctl implementation
+ * needs to read in the following structure.
+ *
+ * struct a {
+ *	char	*buf;
+ *	size_t	buflen;
+ * }
+ *
+ * On the first callout to FUSE server, inarg->in_size and
+ * inarg->out_size will be NULL; then, the server completes the ioctl
+ * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
+ * the actual iov array to
+ *
+ * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a) } }
+ *
+ * which tells FUSE to copy in the requested area and retry the ioctl.
+ * On the second round, the server has access to the structure and
+ * from that it can tell what to look for next, so on the invocation,
+ * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
+ *
+ * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a)	},
+ *   { .iov_base = a.buf,	.iov_len = a.buflen		} }
+ *
+ * FUSE will copy both struct a and the pointed buffer from the
+ * process doing the ioctl and retry ioctl with both struct a and the
+ * buffer.
+ *
+ * This time, FUSE server has everything it needs and completes ioctl
+ * without FUSE_IOCTL_RETRY which finishes the ioctl call.
+ *
+ * Copying data out works the same way.
+ *
+ * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
+ * automatically initializes in and out iovs by decoding @cmd with
+ * _IOC_* macros and the server is not allowed to request RETRY.  This
+ * limits ioctl data transfers to well-formed ioctls and is the forced
+ * behavior for all FUSE servers.
+ */
+static long fuse_file_do_ioctl(struct file *file, unsigned int cmd,
+			       unsigned long arg, unsigned int flags)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct fuse_file *ff = file->private_data;
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_ioctl_in inarg = {
+		.fh = ff->fh,
+		.cmd = cmd,
+		.arg = arg,
+		.flags = flags
+	};
+	struct fuse_ioctl_out outarg;
+	struct fuse_req *req = NULL;
+	struct page **pages = NULL;
+	struct page *iov_page = NULL;
+	struct iovec *in_iov = NULL, *out_iov = NULL;
+	unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
+	size_t in_size, out_size, transferred;
+	int err;
+
+	/* assume all the iovs returned by client always fits in a page */
+	BUILD_BUG_ON(sizeof(struct iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
+
+	if (!fuse_allow_task(fc, current))
+		return -EACCES;
+
+	err = -EIO;
+	if (is_bad_inode(inode))
+		goto out;
+
+	err = -ENOMEM;
+	pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL);
+	iov_page = alloc_page(GFP_KERNEL);
+	if (!pages || !iov_page)
+		goto out;
+
+	/*
+	 * If restricted, initialize IO parameters as encoded in @cmd.
+	 * RETRY from server is not allowed.
+	 */
+	if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
+		struct iovec *iov = page_address(iov_page);
+
+		iov->iov_base = (void __user *)arg;
+		iov->iov_len = _IOC_SIZE(cmd);
+
+		if (_IOC_DIR(cmd) & _IOC_WRITE) {
+			in_iov = iov;
+			in_iovs = 1;
+		}
+
+		if (_IOC_DIR(cmd) & _IOC_READ) {
+			out_iov = iov;
+			out_iovs = 1;
+		}
+	}
+
+ retry:
+	inarg.in_size = in_size = iov_length(in_iov, in_iovs);
+	inarg.out_size = out_size = iov_length(out_iov, out_iovs);
+
+	/*
+	 * Out data can be used either for actual out data or iovs,
+	 * make sure there always is at least one page.
+	 */
+	out_size = max_t(size_t, out_size, PAGE_SIZE);
+	max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
+
+	/* make sure there are enough buffer pages and init request with them */
+	err = -ENOMEM;
+	if (max_pages > FUSE_MAX_PAGES_PER_REQ)
+		goto out;
+	while (num_pages < max_pages) {
+		pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+		if (!pages[num_pages])
+			goto out;
+		num_pages++;
+	}
+
+	req = fuse_get_req(fc);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		req = NULL;
+		goto out;
+	}
+	memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
+	req->num_pages = num_pages;
+
+	/* okay, let's send it to the client */
+	req->in.h.opcode = FUSE_IOCTL;
+	req->in.h.nodeid = get_node_id(inode);
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(inarg);
+	req->in.args[0].value = &inarg;
+	if (in_size) {
+		req->in.numargs++;
+		req->in.args[1].size = in_size;
+		req->in.argpages = 1;
+
+		err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
+					   false);
+		if (err)
+			goto out;
+	}
+
+	req->out.numargs = 2;
+	req->out.args[0].size = sizeof(outarg);
+	req->out.args[0].value = &outarg;
+	req->out.args[1].size = out_size;
+	req->out.argpages = 1;
+	req->out.argvar = 1;
+
+	fuse_request_send(fc, req);
+	err = req->out.h.error;
+	transferred = req->out.args[1].size;
+	fuse_put_request(fc, req);
+	req = NULL;
+	if (err)
+		goto out;
+
+	/* did it ask for retry? */
+	if (outarg.flags & FUSE_IOCTL_RETRY) {
+		char *vaddr;
+
+		/* no retry if in restricted mode */
+		err = -EIO;
+		if (!(flags & FUSE_IOCTL_UNRESTRICTED))
+			goto out;
+
+		in_iovs = outarg.in_iovs;
+		out_iovs = outarg.out_iovs;
+
+		/*
+		 * Make sure things are in boundary, separate checks
+		 * are to protect against overflow.
+		 */
+		err = -ENOMEM;
+		if (in_iovs > FUSE_IOCTL_MAX_IOV ||
+		    out_iovs > FUSE_IOCTL_MAX_IOV ||
+		    in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
+			goto out;
+
+		err = -EIO;
+		if ((in_iovs + out_iovs) * sizeof(struct iovec) != transferred)
+			goto out;
+
+		/* okay, copy in iovs and retry */
+		vaddr = kmap_atomic(pages[0], KM_USER0);
+		memcpy(page_address(iov_page), vaddr, transferred);
+		kunmap_atomic(vaddr, KM_USER0);
+
+		in_iov = page_address(iov_page);
+		out_iov = in_iov + in_iovs;
+
+		goto retry;
+	}
+
+	err = -EIO;
+	if (transferred > inarg.out_size)
+		goto out;
+
+	err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
+ out:
+	if (req)
+		fuse_put_request(fc, req);
+	if (iov_page)
+		__free_page(iov_page);
+	while (num_pages)
+		__free_page(pages[--num_pages]);
+	kfree(pages);
+
+	return err ? err : outarg.result;
+}
+
+static long fuse_file_ioctl(struct file *file, unsigned int cmd,
+			    unsigned long arg)
+{
+	return fuse_file_do_ioctl(file, cmd, arg, 0);
+}
+
+static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
+				   unsigned long arg)
+{
+	return fuse_file_do_ioctl(file, cmd, arg, FUSE_IOCTL_COMPAT);
+}
+
+/*
+ * All files which have been polled are linked to RB tree
+ * fuse_conn->polled_files which is indexed by kh.  Walk the tree and
+ * find the matching one.
+ */
+static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
+					      struct rb_node **parent_out)
+{
+	struct rb_node **link = &fc->polled_files.rb_node;
+	struct rb_node *last = NULL;
+
+	while (*link) {
+		struct fuse_file *ff;
+
+		last = *link;
+		ff = rb_entry(last, struct fuse_file, polled_node);
+
+		if (kh < ff->kh)
+			link = &last->rb_left;
+		else if (kh > ff->kh)
+			link = &last->rb_right;
+		else
+			return link;
+	}
+
+	if (parent_out)
+		*parent_out = last;
+	return link;
+}
+
+/*
+ * The file is about to be polled.  Make sure it's on the polled_files
+ * RB tree.  Note that files once added to the polled_files tree are
+ * not removed before the file is released.  This is because a file
+ * polled once is likely to be polled again.
+ */
+static void fuse_register_polled_file(struct fuse_conn *fc,
+				      struct fuse_file *ff)
+{
+	spin_lock(&fc->lock);
+	if (RB_EMPTY_NODE(&ff->polled_node)) {
+		struct rb_node **link, *parent;
+
+		link = fuse_find_polled_node(fc, ff->kh, &parent);
+		BUG_ON(*link);
+		rb_link_node(&ff->polled_node, parent, link);
+		rb_insert_color(&ff->polled_node, &fc->polled_files);
+	}
+	spin_unlock(&fc->lock);
+}
+
+static unsigned fuse_file_poll(struct file *file, poll_table *wait)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct fuse_file *ff = file->private_data;
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
+	struct fuse_poll_out outarg;
+	struct fuse_req *req;
+	int err;
+
+	if (fc->no_poll)
+		return DEFAULT_POLLMASK;
+
+	poll_wait(file, &ff->poll_wait, wait);
+
+	/*
+	 * Ask for notification iff there's someone waiting for it.
+	 * The client may ignore the flag and always notify.
+	 */
+	if (waitqueue_active(&ff->poll_wait)) {
+		inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
+		fuse_register_polled_file(fc, ff);
+	}
+
+	req = fuse_get_req(fc);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	req->in.h.opcode = FUSE_POLL;
+	req->in.h.nodeid = get_node_id(inode);
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(inarg);
+	req->in.args[0].value = &inarg;
+	req->out.numargs = 1;
+	req->out.args[0].size = sizeof(outarg);
+	req->out.args[0].value = &outarg;
+	fuse_request_send(fc, req);
+	err = req->out.h.error;
+	fuse_put_request(fc, req);
+
+	if (!err)
+		return outarg.revents;
+	if (err == -ENOSYS) {
+		fc->no_poll = 1;
+		return DEFAULT_POLLMASK;
+	}
+	return POLLERR;
+}
+
+/*
+ * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
+ * wakes up the poll waiters.
+ */
+int fuse_notify_poll_wakeup(struct fuse_conn *fc,
+			    struct fuse_notify_poll_wakeup_out *outarg)
+{
+	u64 kh = outarg->kh;
+	struct rb_node **link;
+
+	spin_lock(&fc->lock);
+
+	link = fuse_find_polled_node(fc, kh, NULL);
+	if (*link) {
+		struct fuse_file *ff;
+
+		ff = rb_entry(*link, struct fuse_file, polled_node);
+		wake_up_interruptible_sync(&ff->poll_wait);
+	}
+
+	spin_unlock(&fc->lock);
+	return 0;
+}
+
 static const struct file_operations fuse_file_operations = {
-	.llseek		= generic_file_llseek,
+	.llseek		= fuse_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.aio_read	= fuse_file_aio_read,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.aio_write	= fuse_file_aio_write,
 	.mmap		= fuse_file_mmap,
 	.open		= fuse_open,
 	.flush		= fuse_flush,
@@ -869,27 +1926,36 @@ static const struct file_operations fuse_file_operations = {
 	.lock		= fuse_file_lock,
 	.flock		= fuse_file_flock,
 	.splice_read	= generic_file_splice_read,
+	.unlocked_ioctl	= fuse_file_ioctl,
+	.compat_ioctl	= fuse_file_compat_ioctl,
+	.poll		= fuse_file_poll,
 };
 
 static const struct file_operations fuse_direct_io_file_operations = {
-	.llseek		= generic_file_llseek,
+	.llseek		= fuse_file_llseek,
 	.read		= fuse_direct_read,
 	.write		= fuse_direct_write,
+	.mmap		= fuse_direct_mmap,
 	.open		= fuse_open,
 	.flush		= fuse_flush,
 	.release	= fuse_release,
 	.fsync		= fuse_fsync,
 	.lock		= fuse_file_lock,
 	.flock		= fuse_file_flock,
-	/* no mmap and splice_read */
+	.unlocked_ioctl	= fuse_file_ioctl,
+	.compat_ioctl	= fuse_file_compat_ioctl,
+	.poll		= fuse_file_poll,
+	/* no splice_read */
 };
 
 static const struct address_space_operations fuse_file_aops  = {
 	.readpage	= fuse_readpage,
+	.writepage	= fuse_writepage,
+	.launder_page	= fuse_launder_page,
 	.write_begin	= fuse_write_begin,
 	.write_end	= fuse_write_end,
 	.readpages	= fuse_readpages,
-	.set_page_dirty	= fuse_set_page_dirty,
+	.set_page_dirty	= __set_page_dirty_nobuffers,
 	.bmap		= fuse_bmap,
 };