[net-next-2.6.git] / fs / 9p / vfs_file.c

/*
 *  linux/fs/9p/vfs_file.c
 *
 * This file contians vfs file ops for 9P2000.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <asm/uaccess.h>
#include <linux/idr.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
#include "cache.h"

static const struct file_operations v9fs_cached_file_operations;

/**
 * v9fs_file_open - open a file (or directory)
 * @inode: inode to be opened
 * @file: file being opened
 *
 */

int v9fs_file_open(struct inode *inode, struct file *file)
{
	int err;
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	int omode;

	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
	v9ses = v9fs_inode2v9ses(inode);
	if (v9fs_proto_dotl(v9ses))
		omode = file->f_flags;
	else
		omode = v9fs_uflags2omode(file->f_flags,
					v9fs_proto_dotu(v9ses));
	fid = file->private_data;
	if (!fid) {
		fid = v9fs_fid_clone(file->f_path.dentry);
		if (IS_ERR(fid))
			return PTR_ERR(fid);

		err = p9_client_open(fid, omode);
		if (err < 0) {
			p9_client_clunk(fid);
			return err;
		}
		if (file->f_flags & O_TRUNC) {
			i_size_write(inode, 0);
			inode->i_blocks = 0;
		}
		if ((file->f_flags & O_APPEND) &&
			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
			generic_file_llseek(file, 0, SEEK_END);
	}

	file->private_data = fid;
	if ((fid->qid.version) && (v9ses->cache)) {
		P9_DPRINTK(P9_DEBUG_VFS, "cached");
		/* enable cached file options */
		if(file->f_op == &v9fs_file_operations)
			file->f_op = &v9fs_cached_file_operations;

#ifdef CONFIG_9P_FSCACHE
		v9fs_cache_inode_set_cookie(inode, file);
#endif
	}

	return 0;
}

/**
 * v9fs_file_lock - lock a file (or directory)
 * @filp: file to be locked
 * @cmd: lock command
 * @fl: file lock structure
 *
 * Bugs: this looks like a local only lock, we should extend into 9P
 *       by using open exclusive
 */

static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
{
	int res = 0;
	struct inode *inode = filp->f_path.dentry->d_inode;

	P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

	/* No mandatory locks */
	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
		return -ENOLCK;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
		filemap_write_and_wait(inode->i_mapping);
		invalidate_mapping_pages(&inode->i_data, 0, -1);
	}

	return res;
}

/**
 * v9fs_file_readn - read from a file
 * @filp: file pointer to read
 * @data: data buffer to read data into
 * @udata: user data buffer to read data into
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */

ssize_t
v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
	       u64 offset)
{
	int n, total, size;
	struct p9_fid *fid = filp->private_data;

	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
					(long long unsigned) offset, count);

	n = 0;
	total = 0;
	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
	do {
		n = p9_client_read(fid, data, udata, offset, count);
		if (n <= 0)
			break;

		if (data)
			data += n;
		if (udata)
			udata += n;

		offset += n;
		count -= n;
		total += n;
	} while (count > 0 && n == size);

	if (n < 0)
		total = n;

	return total;
}

/**
 * v9fs_file_read - read from a file
 * @filp: file pointer to read
 * @udata: user data buffer to read data into
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */

static ssize_t
v9fs_file_read(struct file *filp, char __user *udata, size_t count,
	       loff_t * offset)
{
	int ret;
	struct p9_fid *fid;
	size_t size;

	P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
	fid = filp->private_data;

	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
	if (count > size)
		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
	else
		ret = p9_client_read(fid, NULL, udata, *offset, count);

	if (ret > 0)
		*offset += ret;

	return ret;
}

/**
 * v9fs_file_write - write to a file
 * @filp: file pointer to write
 * @data: data buffer to write data from
 * @count: size of buffer
 * @offset: offset at which to write data
 *
 */

static ssize_t
v9fs_file_write(struct file *filp, const char __user * data,
		size_t count, loff_t * offset)
{
	int n, rsize, total = 0;
	struct p9_fid *fid;
	struct p9_client *clnt;
	struct inode *inode = filp->f_path.dentry->d_inode;
	loff_t origin = *offset;
	unsigned long pg_start, pg_end;

	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
		(int)count, (int)*offset);

	fid = filp->private_data;
	clnt = fid->clnt;

	rsize = fid->iounit ? fid->iounit : clnt->msize - P9_IOHDRSZ;

	do {
		if (count < rsize)
			rsize = count;

		n = p9_client_write(fid, NULL, data+total, origin+total,
									rsize);
		if (n <= 0)
			break;
		count -= n;
		total += n;
	} while (count > 0);

	if (total > 0) {
		pg_start = origin >> PAGE_CACHE_SHIFT;
		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
		if (inode->i_mapping && inode->i_mapping->nrpages)
			invalidate_inode_pages2_range(inode->i_mapping,
						      pg_start, pg_end);
		*offset += total;
		i_size_write(inode, i_size_read(inode) + total);
		inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
	}

	if (n < 0)
		return n;

	return total;
}

static int v9fs_file_fsync(struct file *filp, int datasync)
{
	struct p9_fid *fid;
	struct p9_wstat wstat;
	int retval;

	P9_DPRINTK(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);

	fid = filp->private_data;
	v9fs_blank_wstat(&wstat);

	retval = p9_client_wstat(fid, &wstat);
	return retval;
}

static const struct file_operations v9fs_cached_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.aio_read = generic_file_aio_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_readonly_mmap,
	.fsync = v9fs_file_fsync,
};

const struct file_operations v9fs_file_operations = {
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_readonly_mmap,
	.fsync = v9fs_file_fsync,
};

const struct file_operations v9fs_file_operations_dotl = {
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_readonly_mmap,
	.fsync = v9fs_file_fsync,
};
Commit	Line	Data
e69e7fe5 EVH	1	/*
	2	* linux/fs/9p/vfs_file.c
	3	*
	4	* This file contians vfs file ops for 9P2000.
	5	*
	6	* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
	7	* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
42e8c509 EVH	10	* it under the terms of the GNU General Public License version 2
42e8c509 EVH	11	* as published by the Free Software Foundation.
e69e7fe5 EVH	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to:
	20	* Free Software Foundation
	21	* 51 Franklin Street, Fifth Floor
	22	* Boston, MA 02111-1301 USA
	23	*
	24	*/
	25
	26	#include <linux/module.h>
	27	#include <linux/errno.h>
	28	#include <linux/fs.h>
914e2637	29	#include <linux/sched.h>
e69e7fe5 EVH	30	#include <linux/file.h>
	31	#include <linux/stat.h>
	32	#include <linux/string.h>
e69e7fe5	33	#include <linux/inet.h>
e69e7fe5	34	#include <linux/list.h>
637d020a	35	#include <linux/pagemap.h>
e69e7fe5 EVH	36	#include <asm/uaccess.h>
e69e7fe5 EVH	37	#include <linux/idr.h>
bd238fb4 LI	38	#include <net/9p/9p.h>
bd238fb4 LI	39	#include <net/9p/client.h>
e69e7fe5	40
e69e7fe5	41	#include "v9fs.h"
e69e7fe5 EVH	42	#include "v9fs_vfs.h"
e69e7fe5 EVH	43	#include "fid.h"
60e78d2c	44	#include "cache.h"
e69e7fe5	45
d32b687e AB	46	static const struct file_operations v9fs_cached_file_operations;
d32b687e AB	47
e69e7fe5 EVH	48	/**
	49	* v9fs_file_open - open a file (or directory)
	50	* @inode: inode to be opened
	51	* @file: file being opened
	52	*
	53	*/
	54
	55	int v9fs_file_open(struct inode inode, struct file file)
	56	{
6a3124a3	57	int err;
bd238fb4 LI	58	struct v9fs_session_info *v9ses;
	59	struct p9_fid *fid;
	60	int omode;
e69e7fe5	61
ef56547e	62	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
bd238fb4	63	v9ses = v9fs_inode2v9ses(inode);
ef56547e MK	64	if (v9fs_proto_dotl(v9ses))
	65	omode = file->f_flags;
	66	else
	67	omode = v9fs_uflags2omode(file->f_flags,
	68	v9fs_proto_dotu(v9ses));
bd238fb4 LI	69	fid = file->private_data;
	70	if (!fid) {
	71	fid = v9fs_fid_clone(file->f_path.dentry);
	72	if (IS_ERR(fid))
	73	return PTR_ERR(fid);
	74
	75	err = p9_client_open(fid, omode);
9523a841	76	if (err < 0) {
bd238fb4 LI	77	p9_client_clunk(fid);
	78	return err;
	79	}
ef56547e	80	if (file->f_flags & O_TRUNC) {
7549ae3e	81	i_size_write(inode, 0);
9523a841 EVH	82	inode->i_blocks = 0;
9523a841 EVH	83	}
ef56547e MK	84	if ((file->f_flags & O_APPEND) &&
ef56547e MK	85	(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
2e4bef41	86	generic_file_llseek(file, 0, SEEK_END);
6a3124a3	87	}
e69e7fe5	88
bd238fb4 LI	89	file->private_data = fid;
	90	if ((fid->qid.version) && (v9ses->cache)) {
	91	P9_DPRINTK(P9_DEBUG_VFS, "cached");
e03abc0c EVH	92	/* enable cached file options */
	93	if(file->f_op == &v9fs_file_operations)
	94	file->f_op = &v9fs_cached_file_operations;
60e78d2c AK	95
	96	#ifdef CONFIG_9P_FSCACHE
	97	v9fs_cache_inode_set_cookie(inode, file);
	98	#endif
e03abc0c EVH	99	}
e03abc0c EVH	100
6a3124a3	101	return 0;
e69e7fe5 EVH	102	}
	103
	104	/**
	105	* v9fs_file_lock - lock a file (or directory)
ee443996 EVH	106	* @filp: file to be locked
	107	* @cmd: lock command
	108	* @fl: file lock structure
e69e7fe5	109	*
ee443996	110	* Bugs: this looks like a local only lock, we should extend into 9P
e69e7fe5 EVH	111	* by using open exclusive
	112	*/
	113
	114	static int v9fs_file_lock(struct file filp, int cmd, struct file_lock fl)
	115	{
	116	int res = 0;
d6f787bc	117	struct inode *inode = filp->f_path.dentry->d_inode;
e69e7fe5	118
bd238fb4	119	P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
e69e7fe5 EVH	120
e69e7fe5 EVH	121	/* No mandatory locks */
f78233dd	122	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
e69e7fe5 EVH	123	return -ENOLCK;
	124
	125	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
28fd1298	126	filemap_write_and_wait(inode->i_mapping);
fc0ecff6	127	invalidate_mapping_pages(&inode->i_data, 0, -1);
e69e7fe5 EVH	128	}
	129
	130	return res;
	131	}
	132
	133	/**
fbedadc1	134	* v9fs_file_readn - read from a file
ee443996	135	* @filp: file pointer to read
e69e7fe5	136	* @data: data buffer to read data into
fbedadc1	137	* @udata: user data buffer to read data into
e69e7fe5 EVH	138	* @count: size of buffer
	139	* @offset: offset at which to read data
	140	*
	141	*/
fbedadc1 EVH	142
	143	ssize_t
	144	v9fs_file_readn(struct file filp, char data, char __user *udata, u32 count,
	145	u64 offset)
	146	{
97e8442b	147	int n, total, size;
fbedadc1 EVH	148	struct p9_fid *fid = filp->private_data;
fbedadc1 EVH	149
51a87c55	150	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
fbedadc1 EVH	151	(long long unsigned) offset, count);
	152
	153	n = 0;
	154	total = 0;
97e8442b	155	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
fbedadc1 EVH	156	do {
	157	n = p9_client_read(fid, data, udata, offset, count);
	158	if (n <= 0)
	159	break;
	160
	161	if (data)
	162	data += n;
	163	if (udata)
	164	udata += n;
	165
	166	offset += n;
	167	count -= n;
	168	total += n;
97e8442b	169	} while (count > 0 && n == size);
fbedadc1 EVH	170
	171	if (n < 0)
	172	total = n;
	173
	174	return total;
	175	}
	176
	177	/**
	178	* v9fs_file_read - read from a file
	179	* @filp: file pointer to read
	180	* @udata: user data buffer to read data into
	181	* @count: size of buffer
	182	* @offset: offset at which to read data
	183	*
	184	*/
	185
e69e7fe5	186	static ssize_t
fbedadc1	187	v9fs_file_read(struct file filp, char __user udata, size_t count,
19cba8ab	188	loff_t * offset)
e69e7fe5	189	{
bd238fb4 LI	190	int ret;
bd238fb4 LI	191	struct p9_fid *fid;
97e8442b	192	size_t size;
e69e7fe5	193
ea2e7996	194	P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
bd238fb4	195	fid = filp->private_data;
fbedadc1	196
97e8442b MK	197	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
97e8442b MK	198	if (count > size)
fbedadc1 EVH	199	ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
	200	else
	201	ret = p9_client_read(fid, NULL, udata, *offset, count);
	202
bd238fb4 LI	203	if (ret > 0)
bd238fb4 LI	204	*offset += ret;
e69e7fe5	205
bd238fb4	206	return ret;
e69e7fe5 EVH	207	}
	208
	209	/**
19cba8ab	210	* v9fs_file_write - write to a file
ee443996	211	* @filp: file pointer to write
e69e7fe5 EVH	212	* @data: data buffer to write data from
	213	* @count: size of buffer
	214	* @offset: offset at which to write data
	215	*
	216	*/
	217
	218	static ssize_t
19cba8ab LI	219	v9fs_file_write(struct file filp, const char __user data,
19cba8ab LI	220	size_t count, loff_t * offset)
e69e7fe5	221	{
dfb0ec2e	222	int n, rsize, total = 0;
bd238fb4	223	struct p9_fid *fid;
dfb0ec2e	224	struct p9_client *clnt;
9523a841	225	struct inode *inode = filp->f_path.dentry->d_inode;
fc0f2961	226	loff_t origin = *offset;
637d020a	227	unsigned long pg_start, pg_end;
e69e7fe5	228
bd238fb4 LI	229	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
bd238fb4 LI	230	(int)count, (int)*offset);
e69e7fe5	231
bd238fb4	232	fid = filp->private_data;
dfb0ec2e EVH	233	clnt = fid->clnt;
dfb0ec2e EVH	234
97e8442b	235	rsize = fid->iounit ? fid->iounit : clnt->msize - P9_IOHDRSZ;
dfb0ec2e EVH	236
	237	do {
	238	if (count < rsize)
	239	rsize = count;
	240
637d020a	241	n = p9_client_write(fid, NULL, data+total, origin+total,
dfb0ec2e EVH	242	rsize);
	243	if (n <= 0)
	244	break;
	245	count -= n;
	246	total += n;
	247	} while (count > 0);
	248
	249	if (total > 0) {
637d020a AK	250	pg_start = origin >> PAGE_CACHE_SHIFT;
637d020a AK	251	pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
60e78d2c AK	252	if (inode->i_mapping && inode->i_mapping->nrpages)
	253	invalidate_inode_pages2_range(inode->i_mapping,
	254	pg_start, pg_end);
dfb0ec2e	255	*offset += total;
637d020a	256	i_size_write(inode, i_size_read(inode) + total);
7549ae3e	257	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
9523a841 EVH	258	}
9523a841 EVH	259
dfb0ec2e EVH	260	if (n < 0)
	261	return n;
	262
	263	return total;
e69e7fe5 EVH	264	}
e69e7fe5 EVH	265
7ea80859	266	static int v9fs_file_fsync(struct file *filp, int datasync)
7a4439c4 MK	267	{
	268	struct p9_fid *fid;
	269	struct p9_wstat wstat;
	270	int retval;
	271
7ea80859	272	P9_DPRINTK(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
7a4439c4 MK	273
	274	fid = filp->private_data;
	275	v9fs_blank_wstat(&wstat);
	276
	277	retval = p9_client_wstat(fid, &wstat);
	278	return retval;
	279	}
	280
d32b687e	281	static const struct file_operations v9fs_cached_file_operations = {
e03abc0c EVH	282	.llseek = generic_file_llseek,
	283	.read = do_sync_read,
	284	.aio_read = generic_file_aio_read,
	285	.write = v9fs_file_write,
	286	.open = v9fs_file_open,
	287	.release = v9fs_dir_release,
	288	.lock = v9fs_file_lock,
14b8869f	289	.mmap = generic_file_readonly_mmap,
7a4439c4	290	.fsync = v9fs_file_fsync,
e03abc0c EVH	291	};
e03abc0c EVH	292
4b6f5d20	293	const struct file_operations v9fs_file_operations = {
e69e7fe5 EVH	294	.llseek = generic_file_llseek,
	295	.read = v9fs_file_read,
	296	.write = v9fs_file_write,
	297	.open = v9fs_file_open,
	298	.release = v9fs_dir_release,
	299	.lock = v9fs_file_lock,
14b8869f	300	.mmap = generic_file_readonly_mmap,
7a4439c4	301	.fsync = v9fs_file_fsync,
e69e7fe5	302	};
9b6533c9 SK	303
	304	const struct file_operations v9fs_file_operations_dotl = {
	305	.llseek = generic_file_llseek,
	306	.read = v9fs_file_read,
	307	.write = v9fs_file_write,
	308	.open = v9fs_file_open,
	309	.release = v9fs_dir_release,
	310	.lock = v9fs_file_lock,
	311	.mmap = generic_file_readonly_mmap,
	312	.fsync = v9fs_file_fsync,
	313	};