[GitHub/mt8127/android_kernel_alcatel_ttab.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;

int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_open_in inarg;
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;
	/* Restarting the syscall is not allowed if O_CREAT and O_EXCL
	   are both set, because creation will fail on the restart */
	int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL);

	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) {
		int err = fuse_do_getattr(inode);
		if (err)
		 	return err;
	}

	if (excl)
		req = fuse_get_request_nonint(fc);
	else
		req = fuse_get_request(fc);
	if (!req)
		return excl ? -EINTR : -ERESTARTSYS;

	err = -ENOMEM;
	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	if (!ff)
		goto out_put_request;

	ff->release_req = fuse_request_alloc();
	if (!ff->release_req) {
		kfree(ff);
		goto out_put_request;
	}

	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(outarg);
	req->out.args[0].value = &outarg;
	if (excl)
		request_send_nonint(fc, req);
	else
		request_send(fc, req);
	err = req->out.h.error;
	if (err) {
		fuse_request_free(ff->release_req);
		kfree(ff);
	} else {
		if (!isdir && (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;
	}

 out_put_request:
	fuse_put_request(fc, req);
	return err;
}

int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req = ff->release_req;
	struct fuse_release_in *inarg = &req->misc.release_in;

	inarg->fh = ff->fh;
	inarg->flags = file->f_flags & ~O_EXCL;
	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
	req->in.h.nodeid = get_node_id(inode);
	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);

	/* 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 (fc->no_flush)
		return 0;

	req = fuse_get_request_nonint(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_nonint(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_flush = 1;
		err = 0;
	}
	return err;
}

static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
	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 (fc->no_fsync)
		return 0;

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

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
	req->in.h.opcode = 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) {
		fc->no_fsync = 1;
		err = 0;
	}
	return err;
}

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_nonint(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);
	loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
	struct fuse_req *req = fuse_get_request_nonint(fc);
	int err = -EINTR;
	if (!req)
		goto out;

	req->out.page_zeroing = 1;
	req->num_pages = 1;
	req->pages[0] = page;
	fuse_send_read(req, file, inode, pos, 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 = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
	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;
	data.file = file;
	data.inode = inode;
	data.req = fuse_get_request_nonint(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_nonint(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 = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
	struct fuse_req *req = fuse_get_request_nonint(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(npages, 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 = fuse_get_request(fc);
	if (!req)
		return -ERESTARTSYS;

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