[net-next-2.6.git] / fs / fuse / file.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2005  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>

static struct file_operations fuse_direct_io_file_operations;

static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
			  struct fuse_open_out *outargp)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_open_in inarg;
	struct fuse_req *req;
	int err;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	memset(&inarg, 0, sizeof(inarg));
	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = 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(*outargp);
	req->out.args[0].value = outargp;
	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 *ff;
	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	if (ff) {
		ff->release_req = fuse_request_alloc();
		if (!ff->release_req) {
			kfree(ff);
			ff = NULL;
		}
	}
	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
	fuse_request_free(ff->release_req);
	kfree(ff);
}

void fuse_finish_open(struct inode *inode, struct file *file,
		      struct fuse_file *ff, struct fuse_open_out *outarg)
{
	if (outarg->open_flags & FOPEN_DIRECT_IO)
		file->f_op = &fuse_direct_io_file_operations;
	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
		invalidate_inode_pages(inode->i_mapping);
	ff->fh = outarg->fh;
	file->private_data = ff;
}

int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;

	/* VFS checks this, but only _after_ ->open() */
	if (file->f_flags & O_DIRECT)
		return -EINVAL;

	err = generic_file_open(inode, file);
	if (err)
		return err;

	/* If opening the root node, no lookup has been performed on
	   it, so the attributes must be refreshed */
	if (get_node_id(inode) == FUSE_ROOT_ID) {
		err = fuse_do_getattr(inode);
		if (err)
		 	return err;
	}

	ff = fuse_file_alloc();
	if (!ff)
		return -ENOMEM;

	err = fuse_send_open(inode, file, isdir, &outarg);
	if (err)
		fuse_file_free(ff);
	else {
		if (isdir)
			outarg.open_flags &= ~FOPEN_DIRECT_IO;
		fuse_finish_open(inode, file, ff, &outarg);
	}

	return err;
}

void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
		       u64 nodeid, struct inode *inode, int flags, int isdir)
{
	struct fuse_req * req = ff->release_req;
	struct fuse_release_in *inarg = &req->misc.release_in;

	inarg->fh = ff->fh;
	inarg->flags = flags;
	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
	req->in.h.nodeid = nodeid;
	req->inode = inode;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
	request_send_background(fc, req);
	kfree(ff);
}

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);
		u64 nodeid = get_node_id(inode);
		fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
	}

	/* Return value is ignored by VFS */
	return 0;
}

static int fuse_open(struct inode *inode, struct file *file)
{
	return fuse_open_common(inode, file, 0);
}

static int fuse_release(struct inode *inode, struct file *file)
{
	return fuse_release_common(inode, file, 0);
}

static int fuse_flush(struct file *file)
{
	struct inode *inode = file->f_dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_flush_in inarg;
	int err;

	if (is_bad_inode(inode))
		return -EIO;

	if (fc->no_flush)
		return 0;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	req->in.h.opcode = FUSE_FLUSH;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	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, struct dentry *de, int datasync,
		      int isdir)
{
	struct inode *inode = de->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_fsync_in inarg;
	int err;

	if (is_bad_inode(inode))
		return -EIO;

	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
		return 0;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
		err = 0;
	}
	return err;
}

static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
	return fuse_fsync_common(file, de, datasync, 0);
}

size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
			     struct inode *inode, loff_t pos, size_t count,
			     int isdir)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_read_in inarg;

	memset(&inarg, 0, sizeof(struct fuse_read_in));
	inarg.fh = ff->fh;
	inarg.offset = pos;
	inarg.size = count;
	req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	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;
	request_send(fc, req);
	return req->out.args[0].size;
}

static inline size_t fuse_send_read(struct fuse_req *req, struct file *file,
				    struct inode *inode, loff_t pos,
				    size_t count)
{
	return fuse_send_read_common(req, file, inode, pos, count, 0);
}

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;
	int err;

	err = -EIO;
	if (is_bad_inode(inode))
		goto out;

	err = -EINTR;
	req = fuse_get_request(fc);
	if (!req)
		goto out;

	req->out.page_zeroing = 1;
	req->num_pages = 1;
	req->pages[0] = page;
	fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
		SetPageUptodate(page);
	fuse_invalidate_attr(inode); /* atime changed */
 out:
	unlock_page(page);
	return err;
}

static int fuse_send_readpages(struct fuse_req *req, struct file *file,
			       struct inode *inode)
{
	loff_t pos = page_offset(req->pages[0]);
	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
	unsigned i;
	req->out.page_zeroing = 1;
	fuse_send_read(req, file, inode, pos, count);
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
		unlock_page(page);
	}
	return req->out.h.error;
}

struct fuse_readpages_data {
	struct fuse_req *req;
	struct file *file;
	struct inode *inode;
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
	struct fuse_readpages_data *data = _data;
	struct fuse_req *req = data->req;
	struct inode *inode = data->inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

	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 err = fuse_send_readpages(req, data->file, inode);
		if (err) {
			unlock_page(page);
			return err;
		}
		fuse_reset_request(req);
	}
	req->pages[req->num_pages] = page;
	req->num_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_readpages_data data;
	int err;

	if (is_bad_inode(inode))
		return -EIO;

	data.file = file;
	data.inode = inode;
	data.req = fuse_get_request(fc);
	if (!data.req)
		return -EINTR;

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
	if (!err && data.req->num_pages)
		err = fuse_send_readpages(data.req, file, inode);
	fuse_put_request(fc, data.req);
	fuse_invalidate_attr(inode); /* atime changed */
	return err;
}

static size_t fuse_send_write(struct fuse_req *req, struct file *file,
			      struct inode *inode, loff_t pos, size_t count)
{
	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;

	memset(&inarg, 0, sizeof(struct fuse_write_in));
	inarg.fh = ff->fh;
	inarg.offset = pos;
	inarg.size = count;
	req->in.h.opcode = FUSE_WRITE;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.argpages = 1;
	req->in.numargs = 2;
	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;
}

static int fuse_prepare_write(struct file *file, struct page *page,
			      unsigned offset, unsigned to)
{
	/* No op */
	return 0;
}

static int fuse_commit_write(struct file *file, struct page *page,
			     unsigned offset, unsigned to)
{
	int err;
	size_t nres;
	unsigned count = to - offset;
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	loff_t pos = page_offset(page) + offset;
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	req->num_pages = 1;
	req->pages[0] = page;
	req->page_offset = offset;
	nres = fuse_send_write(req, file, inode, pos, count);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err && nres != count)
		err = -EIO;
	if (!err) {
		pos += count;
		if (pos > i_size_read(inode))
			i_size_write(inode, pos);

		if (offset == 0 && to == PAGE_CACHE_SIZE) {
			clear_page_dirty(page);
			SetPageUptodate(page);
		}
	}
	fuse_invalidate_attr(inode);
	return err;
}

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 int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
			       unsigned nbytes, int write)
{
	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;

	nbytes = min(nbytes, (unsigned) 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);
	down_read(&current->mm->mmap_sem);
	npages = get_user_pages(current, current->mm, user_addr, npages, write,
				0, req->pages, NULL);
	up_read(&current->mm->mmap_sem);
	if (npages < 0)
		return npages;

	req->num_pages = npages;
	req->page_offset = offset;
	return 0;
}

static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
			      size_t count, loff_t *ppos, int write)
{
	struct inode *inode = file->f_dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	size_t nmax = write ? fc->max_write : fc->max_read;
	loff_t pos = *ppos;
	ssize_t res = 0;
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	while (count) {
		size_t nres;
		size_t nbytes = min(count, nmax);
		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);
		else
			nres = fuse_send_read(req, file, inode, pos, nbytes);
		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;
		buf += nres;
		if (nres != nbytes)
			break;
		if (count)
			fuse_reset_request(req);
	}
	fuse_put_request(fc, req);
	if (res > 0) {
		if (write && pos > i_size_read(inode))
			i_size_write(inode, pos);
		*ppos = pos;
	}
	fuse_invalidate_attr(inode);

	return res;
}

static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
	return fuse_direct_io(file, buf, count, ppos, 0);
}

static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_dentry->d_inode;
	ssize_t res;
	/* Don't allow parallel writes to the same file */
	down(&inode->i_sem);
	res = fuse_direct_io(file, buf, count, ppos, 1);
	up(&inode->i_sem);
	return res;
}

static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if ((vma->vm_flags & VM_SHARED)) {
		if ((vma->vm_flags & VM_WRITE))
			return -ENODEV;
		else
			vma->vm_flags &= ~VM_MAYWRITE;
	}
	return generic_file_mmap(file, vma);
}

static int fuse_set_page_dirty(struct page *page)
{
	printk("fuse_set_page_dirty: should not happen\n");
	dump_stack();
	return 0;
}

static struct file_operations fuse_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_file_read,
	.write		= generic_file_write,
	.mmap		= fuse_file_mmap,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
	.sendfile	= generic_file_sendfile,
};

static struct file_operations fuse_direct_io_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= fuse_direct_read,
	.write		= fuse_direct_write,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
	/* no mmap and sendfile */
};

static struct address_space_operations fuse_file_aops  = {
	.readpage	= fuse_readpage,
	.prepare_write	= fuse_prepare_write,
	.commit_write	= fuse_commit_write,
	.readpages	= fuse_readpages,
	.set_page_dirty	= fuse_set_page_dirty,
};

void fuse_init_file_inode(struct inode *inode)
{
	inode->i_fop = &fuse_file_operations;
	inode->i_data.a_ops = &fuse_file_aops;
}
Commit	Line	Data
b6aeaded MS	1	/*
	2	FUSE: Filesystem in Userspace
	3	Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
	4
	5	This program can be distributed under the terms of the GNU GPL.
	6	See the file COPYING.
	7	*/
	8
	9	#include "fuse_i.h"
	10
	11	#include <linux/pagemap.h>
	12	#include <linux/slab.h>
	13	#include <linux/kernel.h>
	14
45323fb7 MS	15	static struct file_operations fuse_direct_io_file_operations;
45323fb7 MS	16
fd72faac MS	17	static int fuse_send_open(struct inode inode, struct file file, int isdir,
fd72faac MS	18	struct fuse_open_out *outargp)
b6aeaded MS	19	{
b6aeaded MS	20	struct fuse_conn *fc = get_fuse_conn(inode);
b6aeaded	21	struct fuse_open_in inarg;
fd72faac MS	22	struct fuse_req *req;
	23	int err;
	24
	25	req = fuse_get_request(fc);
	26	if (!req)
	27	return -EINTR;
	28
	29	memset(&inarg, 0, sizeof(inarg));
	30	inarg.flags = file->f_flags & ~(O_CREAT \| O_EXCL \| O_NOCTTY \| O_TRUNC);
	31	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
	32	req->in.h.nodeid = get_node_id(inode);
	33	req->inode = inode;
	34	req->in.numargs = 1;
	35	req->in.args[0].size = sizeof(inarg);
	36	req->in.args[0].value = &inarg;
	37	req->out.numargs = 1;
	38	req->out.args[0].size = sizeof(*outargp);
	39	req->out.args[0].value = outargp;
	40	request_send(fc, req);
	41	err = req->out.h.error;
	42	fuse_put_request(fc, req);
	43
	44	return err;
	45	}
	46
	47	struct fuse_file *fuse_file_alloc(void)
	48	{
	49	struct fuse_file *ff;
	50	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	51	if (ff) {
	52	ff->release_req = fuse_request_alloc();
	53	if (!ff->release_req) {
	54	kfree(ff);
	55	ff = NULL;
	56	}
	57	}
	58	return ff;
	59	}
	60
	61	void fuse_file_free(struct fuse_file *ff)
	62	{
	63	fuse_request_free(ff->release_req);
	64	kfree(ff);
	65	}
	66
	67	void fuse_finish_open(struct inode inode, struct file file,
	68	struct fuse_file ff, struct fuse_open_out outarg)
	69	{
	70	if (outarg->open_flags & FOPEN_DIRECT_IO)
	71	file->f_op = &fuse_direct_io_file_operations;
	72	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
	73	invalidate_inode_pages(inode->i_mapping);
	74	ff->fh = outarg->fh;
	75	file->private_data = ff;
	76	}
	77
	78	int fuse_open_common(struct inode inode, struct file file, int isdir)
	79	{
b6aeaded MS	80	struct fuse_open_out outarg;
	81	struct fuse_file *ff;
	82	int err;
b6aeaded	83
dd190d06 MS	84	/* VFS checks this, but only _after_ ->open() */
	85	if (file->f_flags & O_DIRECT)
	86	return -EINVAL;
	87
b6aeaded MS	88	err = generic_file_open(inode, file);
	89	if (err)
	90	return err;
	91
	92	/* If opening the root node, no lookup has been performed on
	93	it, so the attributes must be refreshed */
	94	if (get_node_id(inode) == FUSE_ROOT_ID) {
fd72faac	95	err = fuse_do_getattr(inode);
b6aeaded MS	96	if (err)
	97	return err;
	98	}
	99
fd72faac	100	ff = fuse_file_alloc();
b6aeaded	101	if (!ff)
fd72faac	102	return -ENOMEM;
b6aeaded	103
fd72faac MS	104	err = fuse_send_open(inode, file, isdir, &outarg);
	105	if (err)
	106	fuse_file_free(ff);
	107	else {
	108	if (isdir)
	109	outarg.open_flags &= ~FOPEN_DIRECT_IO;
	110	fuse_finish_open(inode, file, ff, &outarg);
b6aeaded MS	111	}
b6aeaded MS	112
b6aeaded MS	113	return err;
	114	}
	115
fd72faac MS	116	void fuse_send_release(struct fuse_conn fc, struct fuse_file ff,
fd72faac MS	117	u64 nodeid, struct inode *inode, int flags, int isdir)
b6aeaded	118	{
fd72faac	119	struct fuse_req * req = ff->release_req;
b6aeaded MS	120	struct fuse_release_in *inarg = &req->misc.release_in;
	121
	122	inarg->fh = ff->fh;
fd72faac	123	inarg->flags = flags;
04730fef	124	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
fd72faac	125	req->in.h.nodeid = nodeid;
b6aeaded MS	126	req->inode = inode;
	127	req->in.numargs = 1;
	128	req->in.args[0].size = sizeof(struct fuse_release_in);
	129	req->in.args[0].value = inarg;
	130	request_send_background(fc, req);
	131	kfree(ff);
fd72faac MS	132	}
	133
	134	int fuse_release_common(struct inode inode, struct file file, int isdir)
	135	{
	136	struct fuse_file *ff = file->private_data;
	137	if (ff) {
	138	struct fuse_conn *fc = get_fuse_conn(inode);
	139	u64 nodeid = get_node_id(inode);
	140	fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
	141	}
b6aeaded MS	142
	143	/* Return value is ignored by VFS */
	144	return 0;
	145	}
	146
04730fef MS	147	static int fuse_open(struct inode inode, struct file file)
	148	{
	149	return fuse_open_common(inode, file, 0);
	150	}
	151
	152	static int fuse_release(struct inode inode, struct file file)
	153	{
	154	return fuse_release_common(inode, file, 0);
	155	}
	156
b6aeaded MS	157	static int fuse_flush(struct file *file)
	158	{
	159	struct inode *inode = file->f_dentry->d_inode;
	160	struct fuse_conn *fc = get_fuse_conn(inode);
	161	struct fuse_file *ff = file->private_data;
	162	struct fuse_req *req;
	163	struct fuse_flush_in inarg;
	164	int err;
	165
248d86e8 MS	166	if (is_bad_inode(inode))
	167	return -EIO;
	168
b6aeaded MS	169	if (fc->no_flush)
	170	return 0;
	171
7c352bdf	172	req = fuse_get_request(fc);
b6aeaded MS	173	if (!req)
	174	return -EINTR;
	175
	176	memset(&inarg, 0, sizeof(inarg));
	177	inarg.fh = ff->fh;
	178	req->in.h.opcode = FUSE_FLUSH;
	179	req->in.h.nodeid = get_node_id(inode);
	180	req->inode = inode;
	181	req->file = file;
	182	req->in.numargs = 1;
	183	req->in.args[0].size = sizeof(inarg);
	184	req->in.args[0].value = &inarg;
7c352bdf	185	request_send(fc, req);
b6aeaded MS	186	err = req->out.h.error;
	187	fuse_put_request(fc, req);
	188	if (err == -ENOSYS) {
	189	fc->no_flush = 1;
	190	err = 0;
	191	}
	192	return err;
	193	}
	194
82547981 MS	195	int fuse_fsync_common(struct file file, struct dentry de, int datasync,
82547981 MS	196	int isdir)
b6aeaded MS	197	{
	198	struct inode *inode = de->d_inode;
	199	struct fuse_conn *fc = get_fuse_conn(inode);
	200	struct fuse_file *ff = file->private_data;
	201	struct fuse_req *req;
	202	struct fuse_fsync_in inarg;
	203	int err;
	204
248d86e8 MS	205	if (is_bad_inode(inode))
	206	return -EIO;
	207
82547981	208	if ((!isdir && fc->no_fsync) \|\| (isdir && fc->no_fsyncdir))
b6aeaded MS	209	return 0;
	210
	211	req = fuse_get_request(fc);
	212	if (!req)
7c352bdf	213	return -EINTR;
b6aeaded MS	214
	215	memset(&inarg, 0, sizeof(inarg));
	216	inarg.fh = ff->fh;
	217	inarg.fsync_flags = datasync ? 1 : 0;
82547981	218	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
b6aeaded MS	219	req->in.h.nodeid = get_node_id(inode);
	220	req->inode = inode;
	221	req->file = file;
	222	req->in.numargs = 1;
	223	req->in.args[0].size = sizeof(inarg);
	224	req->in.args[0].value = &inarg;
	225	request_send(fc, req);
	226	err = req->out.h.error;
	227	fuse_put_request(fc, req);
	228	if (err == -ENOSYS) {
82547981 MS	229	if (isdir)
	230	fc->no_fsyncdir = 1;
	231	else
	232	fc->no_fsync = 1;
b6aeaded MS	233	err = 0;
	234	}
	235	return err;
	236	}
	237
82547981 MS	238	static int fuse_fsync(struct file file, struct dentry de, int datasync)
	239	{
	240	return fuse_fsync_common(file, de, datasync, 0);
	241	}
	242
04730fef MS	243	size_t fuse_send_read_common(struct fuse_req req, struct file file,
	244	struct inode *inode, loff_t pos, size_t count,
	245	int isdir)
b6aeaded MS	246	{
	247	struct fuse_conn *fc = get_fuse_conn(inode);
	248	struct fuse_file *ff = file->private_data;
	249	struct fuse_read_in inarg;
	250
	251	memset(&inarg, 0, sizeof(struct fuse_read_in));
	252	inarg.fh = ff->fh;
	253	inarg.offset = pos;
	254	inarg.size = count;
04730fef	255	req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
b6aeaded MS	256	req->in.h.nodeid = get_node_id(inode);
	257	req->inode = inode;
	258	req->file = file;
	259	req->in.numargs = 1;
	260	req->in.args[0].size = sizeof(struct fuse_read_in);
	261	req->in.args[0].value = &inarg;
	262	req->out.argpages = 1;
	263	req->out.argvar = 1;
	264	req->out.numargs = 1;
	265	req->out.args[0].size = count;
7c352bdf	266	request_send(fc, req);
b6aeaded MS	267	return req->out.args[0].size;
	268	}
	269
04730fef MS	270	static inline size_t fuse_send_read(struct fuse_req req, struct file file,
	271	struct inode *inode, loff_t pos,
	272	size_t count)
	273	{
	274	return fuse_send_read_common(req, file, inode, pos, count, 0);
	275	}
	276
b6aeaded MS	277	static int fuse_readpage(struct file file, struct page page)
	278	{
	279	struct inode *inode = page->mapping->host;
	280	struct fuse_conn *fc = get_fuse_conn(inode);
248d86e8 MS	281	struct fuse_req *req;
	282	int err;
	283
	284	err = -EIO;
	285	if (is_bad_inode(inode))
	286	goto out;
	287
	288	err = -EINTR;
	289	req = fuse_get_request(fc);
b6aeaded MS	290	if (!req)
	291	goto out;
	292
	293	req->out.page_zeroing = 1;
	294	req->num_pages = 1;
	295	req->pages[0] = page;
4633a22e	296	fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
b6aeaded MS	297	err = req->out.h.error;
	298	fuse_put_request(fc, req);
	299	if (!err)
	300	SetPageUptodate(page);
b36c31ba	301	fuse_invalidate_attr(inode); /* atime changed */
b6aeaded MS	302	out:
	303	unlock_page(page);
	304	return err;
	305	}
	306
db50b96c MS	307	static int fuse_send_readpages(struct fuse_req req, struct file file,
	308	struct inode *inode)
	309	{
4633a22e	310	loff_t pos = page_offset(req->pages[0]);
db50b96c MS	311	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
	312	unsigned i;
	313	req->out.page_zeroing = 1;
	314	fuse_send_read(req, file, inode, pos, count);
	315	for (i = 0; i < req->num_pages; i++) {
	316	struct page *page = req->pages[i];
	317	if (!req->out.h.error)
	318	SetPageUptodate(page);
	319	unlock_page(page);
	320	}
	321	return req->out.h.error;
	322	}
	323
	324	struct fuse_readpages_data {
	325	struct fuse_req *req;
	326	struct file *file;
	327	struct inode *inode;
	328	};
	329
	330	static int fuse_readpages_fill(void _data, struct page page)
	331	{
	332	struct fuse_readpages_data *data = _data;
	333	struct fuse_req *req = data->req;
	334	struct inode *inode = data->inode;
	335	struct fuse_conn *fc = get_fuse_conn(inode);
	336
	337	if (req->num_pages &&
	338	(req->num_pages == FUSE_MAX_PAGES_PER_REQ \|\|
	339	(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read \|\|
	340	req->pages[req->num_pages - 1]->index + 1 != page->index)) {
	341	int err = fuse_send_readpages(req, data->file, inode);
	342	if (err) {
	343	unlock_page(page);
	344	return err;
	345	}
	346	fuse_reset_request(req);
	347	}
	348	req->pages[req->num_pages] = page;
	349	req->num_pages ++;
	350	return 0;
	351	}
	352
	353	static int fuse_readpages(struct file file, struct address_space mapping,
	354	struct list_head *pages, unsigned nr_pages)
	355	{
	356	struct inode *inode = mapping->host;
	357	struct fuse_conn *fc = get_fuse_conn(inode);
	358	struct fuse_readpages_data data;
	359	int err;
248d86e8 MS	360
	361	if (is_bad_inode(inode))
	362	return -EIO;
	363
db50b96c MS	364	data.file = file;
db50b96c MS	365	data.inode = inode;
7c352bdf	366	data.req = fuse_get_request(fc);
db50b96c MS	367	if (!data.req)
	368	return -EINTR;
	369
	370	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
	371	if (!err && data.req->num_pages)
	372	err = fuse_send_readpages(data.req, file, inode);
	373	fuse_put_request(fc, data.req);
b36c31ba	374	fuse_invalidate_attr(inode); /* atime changed */
db50b96c MS	375	return err;
	376	}
	377
04730fef MS	378	static size_t fuse_send_write(struct fuse_req req, struct file file,
04730fef MS	379	struct inode *inode, loff_t pos, size_t count)
b6aeaded MS	380	{
	381	struct fuse_conn *fc = get_fuse_conn(inode);
	382	struct fuse_file *ff = file->private_data;
	383	struct fuse_write_in inarg;
	384	struct fuse_write_out outarg;
	385
	386	memset(&inarg, 0, sizeof(struct fuse_write_in));
	387	inarg.fh = ff->fh;
	388	inarg.offset = pos;
	389	inarg.size = count;
	390	req->in.h.opcode = FUSE_WRITE;
	391	req->in.h.nodeid = get_node_id(inode);
	392	req->inode = inode;
	393	req->file = file;
	394	req->in.argpages = 1;
	395	req->in.numargs = 2;
	396	req->in.args[0].size = sizeof(struct fuse_write_in);
	397	req->in.args[0].value = &inarg;
	398	req->in.args[1].size = count;
	399	req->out.numargs = 1;
	400	req->out.args[0].size = sizeof(struct fuse_write_out);
	401	req->out.args[0].value = &outarg;
7c352bdf	402	request_send(fc, req);
b6aeaded MS	403	return outarg.size;
	404	}
	405
	406	static int fuse_prepare_write(struct file file, struct page page,
	407	unsigned offset, unsigned to)
	408	{
	409	/* No op */
	410	return 0;
	411	}
	412
	413	static int fuse_commit_write(struct file file, struct page page,
	414	unsigned offset, unsigned to)
	415	{
	416	int err;
04730fef	417	size_t nres;
b6aeaded MS	418	unsigned count = to - offset;
	419	struct inode *inode = page->mapping->host;
	420	struct fuse_conn *fc = get_fuse_conn(inode);
4633a22e	421	loff_t pos = page_offset(page) + offset;
248d86e8 MS	422	struct fuse_req *req;
	423
	424	if (is_bad_inode(inode))
	425	return -EIO;
	426
	427	req = fuse_get_request(fc);
b6aeaded MS	428	if (!req)
	429	return -EINTR;
	430
	431	req->num_pages = 1;
	432	req->pages[0] = page;
	433	req->page_offset = offset;
	434	nres = fuse_send_write(req, file, inode, pos, count);
	435	err = req->out.h.error;
	436	fuse_put_request(fc, req);
	437	if (!err && nres != count)
	438	err = -EIO;
	439	if (!err) {
	440	pos += count;
	441	if (pos > i_size_read(inode))
	442	i_size_write(inode, pos);
	443
	444	if (offset == 0 && to == PAGE_CACHE_SIZE) {
	445	clear_page_dirty(page);
	446	SetPageUptodate(page);
	447	}
b36c31ba MS	448	}
b36c31ba MS	449	fuse_invalidate_attr(inode);
b6aeaded MS	450	return err;
	451	}
	452
413ef8cb MS	453	static void fuse_release_user_pages(struct fuse_req *req, int write)
	454	{
	455	unsigned i;
	456
	457	for (i = 0; i < req->num_pages; i++) {
	458	struct page *page = req->pages[i];
	459	if (write)
	460	set_page_dirty_lock(page);
	461	put_page(page);
	462	}
	463	}
	464
	465	static int fuse_get_user_pages(struct fuse_req req, const char __user buf,
	466	unsigned nbytes, int write)
	467	{
	468	unsigned long user_addr = (unsigned long) buf;
	469	unsigned offset = user_addr & ~PAGE_MASK;
	470	int npages;
	471
	472	/* This doesn't work with nfsd */
	473	if (!current->mm)
	474	return -EPERM;
	475
	476	nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
	477	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
6ad84aca	478	npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
413ef8cb MS	479	down_read(&current->mm->mmap_sem);
	480	npages = get_user_pages(current, current->mm, user_addr, npages, write,
	481	0, req->pages, NULL);
	482	up_read(&current->mm->mmap_sem);
	483	if (npages < 0)
	484	return npages;
	485
	486	req->num_pages = npages;
	487	req->page_offset = offset;
	488	return 0;
	489	}
	490
	491	static ssize_t fuse_direct_io(struct file file, const char __user buf,
	492	size_t count, loff_t *ppos, int write)
	493	{
	494	struct inode *inode = file->f_dentry->d_inode;
	495	struct fuse_conn *fc = get_fuse_conn(inode);
	496	size_t nmax = write ? fc->max_write : fc->max_read;
	497	loff_t pos = *ppos;
	498	ssize_t res = 0;
248d86e8 MS	499	struct fuse_req *req;
	500
	501	if (is_bad_inode(inode))
	502	return -EIO;
	503
	504	req = fuse_get_request(fc);
413ef8cb	505	if (!req)
7c352bdf	506	return -EINTR;
413ef8cb MS	507
413ef8cb MS	508	while (count) {
413ef8cb MS	509	size_t nres;
	510	size_t nbytes = min(count, nmax);
	511	int err = fuse_get_user_pages(req, buf, nbytes, !write);
	512	if (err) {
	513	res = err;
	514	break;
	515	}
6ad84aca MS	516	nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
6ad84aca MS	517	nbytes = min(count, nbytes);
413ef8cb MS	518	if (write)
	519	nres = fuse_send_write(req, file, inode, pos, nbytes);
	520	else
	521	nres = fuse_send_read(req, file, inode, pos, nbytes);
	522	fuse_release_user_pages(req, !write);
	523	if (req->out.h.error) {
	524	if (!res)
	525	res = req->out.h.error;
	526	break;
	527	} else if (nres > nbytes) {
	528	res = -EIO;
	529	break;
	530	}
	531	count -= nres;
	532	res += nres;
	533	pos += nres;
	534	buf += nres;
	535	if (nres != nbytes)
	536	break;
	537	if (count)
	538	fuse_reset_request(req);
	539	}
	540	fuse_put_request(fc, req);
	541	if (res > 0) {
	542	if (write && pos > i_size_read(inode))
	543	i_size_write(inode, pos);
	544	*ppos = pos;
b36c31ba MS	545	}
b36c31ba MS	546	fuse_invalidate_attr(inode);
413ef8cb MS	547
	548	return res;
	549	}
	550
	551	static ssize_t fuse_direct_read(struct file file, char __user buf,
	552	size_t count, loff_t *ppos)
	553	{
	554	return fuse_direct_io(file, buf, count, ppos, 0);
	555	}
	556
	557	static ssize_t fuse_direct_write(struct file file, const char __user buf,
	558	size_t count, loff_t *ppos)
	559	{
	560	struct inode *inode = file->f_dentry->d_inode;
	561	ssize_t res;
	562	/* Don't allow parallel writes to the same file */
	563	down(&inode->i_sem);
	564	res = fuse_direct_io(file, buf, count, ppos, 1);
	565	up(&inode->i_sem);
	566	return res;
	567	}
	568
b6aeaded MS	569	static int fuse_file_mmap(struct file file, struct vm_area_struct vma)
	570	{
	571	if ((vma->vm_flags & VM_SHARED)) {
	572	if ((vma->vm_flags & VM_WRITE))
	573	return -ENODEV;
	574	else
	575	vma->vm_flags &= ~VM_MAYWRITE;
	576	}
	577	return generic_file_mmap(file, vma);
	578	}
	579
	580	static int fuse_set_page_dirty(struct page *page)
	581	{
	582	printk("fuse_set_page_dirty: should not happen\n");
	583	dump_stack();
	584	return 0;
	585	}
	586
	587	static struct file_operations fuse_file_operations = {
	588	.llseek = generic_file_llseek,
	589	.read = generic_file_read,
	590	.write = generic_file_write,
	591	.mmap = fuse_file_mmap,
	592	.open = fuse_open,
	593	.flush = fuse_flush,
	594	.release = fuse_release,
	595	.fsync = fuse_fsync,
	596	.sendfile = generic_file_sendfile,
	597	};
	598
413ef8cb MS	599	static struct file_operations fuse_direct_io_file_operations = {
	600	.llseek = generic_file_llseek,
	601	.read = fuse_direct_read,
	602	.write = fuse_direct_write,
	603	.open = fuse_open,
	604	.flush = fuse_flush,
	605	.release = fuse_release,
	606	.fsync = fuse_fsync,
	607	/* no mmap and sendfile */
	608	};
	609
b6aeaded MS	610	static struct address_space_operations fuse_file_aops = {
	611	.readpage = fuse_readpage,
	612	.prepare_write = fuse_prepare_write,
	613	.commit_write = fuse_commit_write,
db50b96c	614	.readpages = fuse_readpages,
b6aeaded MS	615	.set_page_dirty = fuse_set_page_dirty,
	616	};
	617
	618	void fuse_init_file_inode(struct inode *inode)
	619	{
45323fb7 MS	620	inode->i_fop = &fuse_file_operations;
45323fb7 MS	621	inode->i_data.a_ops = &fuse_file_aops;
b6aeaded	622	}