[deliverable/linux.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 int fuse_open(struct inode *inode, struct file *file)
{
	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 = 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 && !(fc->flags & FUSE_KERNEL_CACHE))
		invalidate_inode_pages(inode->i_mapping);
	if (err) {
		fuse_request_free(ff->release_req);
		kfree(ff);
	} else {
		ff->fh = outarg.fh;
		file->private_data = ff;
	}

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

static int fuse_release(struct inode *inode, struct file *file)
{
	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 = 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_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;
}

static ssize_t fuse_send_read(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_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 = 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 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);
 out:
	unlock_page(page);
	return err;
}

static ssize_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;
	ssize_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);
		}
	} else if (err == -EINTR || err == -EIO)
		fuse_invalidate_attr(inode);
	return err;
}

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 address_space_operations fuse_file_aops  = {
	.readpage	= fuse_readpage,
	.prepare_write	= fuse_prepare_write,
	.commit_write	= fuse_commit_write,
	.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
	15	static int fuse_open(struct inode inode, struct file file)
	16	{
	17	struct fuse_conn *fc = get_fuse_conn(inode);
	18	struct fuse_req *req;
	19	struct fuse_open_in inarg;
	20	struct fuse_open_out outarg;
	21	struct fuse_file *ff;
	22	int err;
	23	/* Restarting the syscall is not allowed if O_CREAT and O_EXCL
	24	are both set, because creation will fail on the restart */
	25	int excl = (file->f_flags & (O_CREAT\|O_EXCL)) == (O_CREAT\|O_EXCL);
	26
	27	err = generic_file_open(inode, file);
	28	if (err)
	29	return err;
	30
	31	/* If opening the root node, no lookup has been performed on
	32	it, so the attributes must be refreshed */
	33	if (get_node_id(inode) == FUSE_ROOT_ID) {
	34	int err = fuse_do_getattr(inode);
	35	if (err)
	36	return err;
	37	}
	38
	39	if (excl)
	40	req = fuse_get_request_nonint(fc);
	41	else
	42	req = fuse_get_request(fc);
	43	if (!req)
	44	return excl ? -EINTR : -ERESTARTSYS;
	45
	46	err = -ENOMEM;
	47	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	48	if (!ff)
	49	goto out_put_request;
	50
	51	ff->release_req = fuse_request_alloc();
	52	if (!ff->release_req) {
	53	kfree(ff);
	54	goto out_put_request;
	55	}
	56
	57	memset(&inarg, 0, sizeof(inarg));
	58	inarg.flags = file->f_flags & ~(O_CREAT \| O_EXCL \| O_NOCTTY \| O_TRUNC);
	59	req->in.h.opcode = FUSE_OPEN;
	60	req->in.h.nodeid = get_node_id(inode);
	61	req->inode = inode;
	62	req->in.numargs = 1;
	63	req->in.args[0].size = sizeof(inarg);
	64	req->in.args[0].value = &inarg;
65	req->out.numargs = 1;
66	req->out.args[0].size = sizeof(outarg);
67	req->out.args[0].value = &outarg;
68	if (excl)
69	request_send_nonint(fc, req);
70	else
71	request_send(fc, req);
72	err = req->out.h.error;
1e9a4ed9	73	if (!err && !(fc->flags & FUSE_KERNEL_CACHE))
b6aeaded MS	74	invalidate_inode_pages(inode->i_mapping);
	75	if (err) {
	76	fuse_request_free(ff->release_req);
	77	kfree(ff);
	78	} else {
	79	ff->fh = outarg.fh;
	80	file->private_data = ff;
	81	}
	82
	83	out_put_request:
	84	fuse_put_request(fc, req);
	85	return err;
	86	}
	87
	88	static int fuse_release(struct inode inode, struct file file)
	89	{
	90	struct fuse_conn *fc = get_fuse_conn(inode);
	91	struct fuse_file *ff = file->private_data;
	92	struct fuse_req *req = ff->release_req;
	93	struct fuse_release_in *inarg = &req->misc.release_in;
	94
	95	inarg->fh = ff->fh;
	96	inarg->flags = file->f_flags & ~O_EXCL;
	97	req->in.h.opcode = FUSE_RELEASE;
	98	req->in.h.nodeid = get_node_id(inode);
	99	req->inode = inode;
	100	req->in.numargs = 1;
	101	req->in.args[0].size = sizeof(struct fuse_release_in);
	102	req->in.args[0].value = inarg;
	103	request_send_background(fc, req);
	104	kfree(ff);
	105
	106	/* Return value is ignored by VFS */
	107	return 0;
	108	}
	109
	110	static int fuse_flush(struct file *file)
	111	{
	112	struct inode *inode = file->f_dentry->d_inode;
	113	struct fuse_conn *fc = get_fuse_conn(inode);
	114	struct fuse_file *ff = file->private_data;
	115	struct fuse_req *req;
	116	struct fuse_flush_in inarg;
	117	int err;
	118
	119	if (fc->no_flush)
	120	return 0;
	121
	122	req = fuse_get_request_nonint(fc);
	123	if (!req)
	124	return -EINTR;
	125
	126	memset(&inarg, 0, sizeof(inarg));
	127	inarg.fh = ff->fh;
	128	req->in.h.opcode = FUSE_FLUSH;
	129	req->in.h.nodeid = get_node_id(inode);
	130	req->inode = inode;
	131	req->file = file;
	132	req->in.numargs = 1;
	133	req->in.args[0].size = sizeof(inarg);
	134	req->in.args[0].value = &inarg;
	135	request_send_nonint(fc, req);
	136	err = req->out.h.error;
	137	fuse_put_request(fc, req);
138	if (err == -ENOSYS) {
139	fc->no_flush = 1;
140	err = 0;
141	}
142	return err;
143	}
144
145	static int fuse_fsync(struct file file, struct dentry de, int datasync)
146	{
147	struct inode *inode = de->d_inode;
148	struct fuse_conn *fc = get_fuse_conn(inode);
149	struct fuse_file *ff = file->private_data;
150	struct fuse_req *req;
151	struct fuse_fsync_in inarg;
152	int err;
153
154	if (fc->no_fsync)
155	return 0;
156
157	req = fuse_get_request(fc);
158	if (!req)
159	return -ERESTARTSYS;
160
161	memset(&inarg, 0, sizeof(inarg));
162	inarg.fh = ff->fh;
163	inarg.fsync_flags = datasync ? 1 : 0;
164	req->in.h.opcode = FUSE_FSYNC;
165	req->in.h.nodeid = get_node_id(inode);
166	req->inode = inode;
167	req->file = file;
168	req->in.numargs = 1;
169	req->in.args[0].size = sizeof(inarg);
170	req->in.args[0].value = &inarg;
171	request_send(fc, req);
172	err = req->out.h.error;
173	fuse_put_request(fc, req);
174	if (err == -ENOSYS) {
175	fc->no_fsync = 1;
176	err = 0;
177	}
178	return err;
179	}
180
181	static ssize_t fuse_send_read(struct fuse_req req, struct file file,
182	struct inode *inode, loff_t pos, size_t count)
183	{
184	struct fuse_conn *fc = get_fuse_conn(inode);
185	struct fuse_file *ff = file->private_data;
186	struct fuse_read_in inarg;
187
188	memset(&inarg, 0, sizeof(struct fuse_read_in));
189	inarg.fh = ff->fh;
190	inarg.offset = pos;
191	inarg.size = count;
192	req->in.h.opcode = FUSE_READ;
193	req->in.h.nodeid = get_node_id(inode);
194	req->inode = inode;
195	req->file = file;
196	req->in.numargs = 1;
197	req->in.args[0].size = sizeof(struct fuse_read_in);
198	req->in.args[0].value = &inarg;
199	req->out.argpages = 1;
200	req->out.argvar = 1;
201	req->out.numargs = 1;
202	req->out.args[0].size = count;
203	request_send_nonint(fc, req);
204	return req->out.args[0].size;
205	}
206
207	static int fuse_readpage(struct file file, struct page page)
208	{
209	struct inode *inode = page->mapping->host;
210	struct fuse_conn *fc = get_fuse_conn(inode);
211	loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
212	struct fuse_req *req = fuse_get_request_nonint(fc);
213	int err = -EINTR;
214	if (!req)
215	goto out;
216
217	req->out.page_zeroing = 1;
218	req->num_pages = 1;
219	req->pages[0] = page;
220	fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);
221	err = req->out.h.error;
222	fuse_put_request(fc, req);
223	if (!err)
224	SetPageUptodate(page);
225	out:
226	unlock_page(page);
227	return err;
228	}
229
230	static ssize_t fuse_send_write(struct fuse_req req, struct file file,
231	struct inode *inode, loff_t pos, size_t count)
232	{
233	struct fuse_conn *fc = get_fuse_conn(inode);
234	struct fuse_file *ff = file->private_data;
235	struct fuse_write_in inarg;
236	struct fuse_write_out outarg;
237
238	memset(&inarg, 0, sizeof(struct fuse_write_in));
239	inarg.fh = ff->fh;
240	inarg.offset = pos;
241	inarg.size = count;
242	req->in.h.opcode = FUSE_WRITE;
243	req->in.h.nodeid = get_node_id(inode);
244	req->inode = inode;
245	req->file = file;
246	req->in.argpages = 1;
247	req->in.numargs = 2;
248	req->in.args[0].size = sizeof(struct fuse_write_in);
249	req->in.args[0].value = &inarg;
250	req->in.args[1].size = count;
251	req->out.numargs = 1;
252	req->out.args[0].size = sizeof(struct fuse_write_out);
253	req->out.args[0].value = &outarg;
254	request_send_nonint(fc, req);
255	return outarg.size;
256	}
257
258	static int fuse_prepare_write(struct file file, struct page page,
259	unsigned offset, unsigned to)
260	{
261	/* No op */
262	return 0;
263	}
264
265	static int fuse_commit_write(struct file file, struct page page,
266	unsigned offset, unsigned to)
267	{
268	int err;
269	ssize_t nres;
270	unsigned count = to - offset;
271	struct inode *inode = page->mapping->host;
272	struct fuse_conn *fc = get_fuse_conn(inode);
273	loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
274	struct fuse_req *req = fuse_get_request_nonint(fc);
275	if (!req)
276	return -EINTR;
277
278	req->num_pages = 1;
279	req->pages[0] = page;
280	req->page_offset = offset;
281	nres = fuse_send_write(req, file, inode, pos, count);
282	err = req->out.h.error;
283	fuse_put_request(fc, req);
284	if (!err && nres != count)
285	err = -EIO;
286	if (!err) {
287	pos += count;
288	if (pos > i_size_read(inode))
289	i_size_write(inode, pos);
290
291	if (offset == 0 && to == PAGE_CACHE_SIZE) {
292	clear_page_dirty(page);
293	SetPageUptodate(page);
294	}
295	} else if (err == -EINTR \|\| err == -EIO)
296	fuse_invalidate_attr(inode);
297	return err;
298	}
299
300	static int fuse_file_mmap(struct file file, struct vm_area_struct vma)
301	{
302	if ((vma->vm_flags & VM_SHARED)) {
303	if ((vma->vm_flags & VM_WRITE))
304	return -ENODEV;
305	else
306	vma->vm_flags &= ~VM_MAYWRITE;
307	}
308	return generic_file_mmap(file, vma);
309	}
310
311	static int fuse_set_page_dirty(struct page *page)
312	{
313	printk("fuse_set_page_dirty: should not happen\n");
314	dump_stack();
315	return 0;
316	}
317
318	static struct file_operations fuse_file_operations = {
319	.llseek = generic_file_llseek,
320	.read = generic_file_read,
321	.write = generic_file_write,
322	.mmap = fuse_file_mmap,
323	.open = fuse_open,
324	.flush = fuse_flush,
325	.release = fuse_release,
326	.fsync = fuse_fsync,
327	.sendfile = generic_file_sendfile,
328	};
329
330	static struct address_space_operations fuse_file_aops = {
331	.readpage = fuse_readpage,
332	.prepare_write = fuse_prepare_write,
333	.commit_write = fuse_commit_write,
334	.set_page_dirty = fuse_set_page_dirty,
335	};
336
337	void fuse_init_file_inode(struct inode *inode)
338	{
339	inode->i_fop = &fuse_file_operations;
340	inode->i_data.a_ops = &fuse_file_aops;
341	}