[deliverable/linux.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 as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <asm/uaccess.h>
#include <linux/idr.h>

#include "debug.h"
#include "v9fs.h"
#include "9p.h"
#include "v9fs_vfs.h"
#include "fid.h"

/**
 * 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)
{
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *v9fid, *fid;
	struct v9fs_fcall *fcall = NULL;
	int open_mode = 0;
	unsigned int iounit = 0;
	int newfid = -1;
	long result = -1;

	dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file);

	v9fid = v9fs_fid_get_created(file->f_dentry);
	if (!v9fid)
		v9fid = v9fs_fid_lookup(file->f_dentry);

	if (!v9fid) {
		dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n");
		return -EBADF;
	}

	if (!v9fid->fidcreate) {
		fid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
		if (fid == NULL) {
			dprintk(DEBUG_ERROR, "Out of Memory\n");
			return -ENOMEM;
		}

		fid->fidopen = 0;
		fid->fidcreate = 0;
		fid->fidclunked = 0;
		fid->iounit = 0;
		fid->v9ses = v9ses;

		newfid = v9fs_get_idpool(&v9ses->fidpool);
		if (newfid < 0) {
			eprintk(KERN_WARNING, "newfid fails!\n");
			return -ENOSPC;
		}

		result =
		    v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, NULL);

		if (result < 0) {
			v9fs_put_idpool(newfid, &v9ses->fidpool);
			dprintk(DEBUG_ERROR, "rewalk didn't work\n");
			return -EBADF;
		}

		fid->fid = newfid;
		v9fid = fid;
		/* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */
		/* translate open mode appropriately */
		open_mode = file->f_flags & 0x3;

		if (file->f_flags & O_EXCL)
			open_mode |= V9FS_OEXCL;

		if (v9ses->extended) {
			if (file->f_flags & O_TRUNC)
				open_mode |= V9FS_OTRUNC;

			if (file->f_flags & O_APPEND)
				open_mode |= V9FS_OAPPEND;
		}

		result = v9fs_t_open(v9ses, newfid, open_mode, &fcall);
		if (result < 0) {
			dprintk(DEBUG_ERROR,
				"open failed, open_mode 0x%x: %s\n", open_mode,
				FCALL_ERROR(fcall));
			kfree(fcall);
			return result;
		}

		iounit = fcall->params.ropen.iounit;
		kfree(fcall);
	} else {
		/* create case */
		newfid = v9fid->fid;
		iounit = v9fid->iounit;
		v9fid->fidcreate = 0;
	}

	file->private_data = v9fid;

	v9fid->rdir_pos = 0;
	v9fid->rdir_fcall = NULL;
	v9fid->fidopen = 1;
	v9fid->filp = file;
	v9fid->iounit = iounit;

	return 0;
}

/**
 * v9fs_file_lock - lock a file (or directory)
 * @inode: inode to be opened
 * @file: file being opened
 *
 * XXX - 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_dentry->d_inode;

	dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

	/* No mandatory locks */
	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
		return -ENOLCK;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
		filemap_fdatawrite(inode->i_mapping);
		filemap_fdatawait(inode->i_mapping);
		invalidate_inode_pages(&inode->i_data);
	}

	return res;
}

/**
 * v9fs_file_read - read from a file
 * @filep: file pointer to read
 * @data: 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 * data, size_t count,
	       loff_t * offset)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *v9f = filp->private_data;
	struct v9fs_fcall *fcall = NULL;
	int fid = v9f->fid;
	int rsize = 0;
	int result = 0;
	int total = 0;
	int n;

	dprintk(DEBUG_VFS, "\n");

	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	if (v9f->iounit != 0 && rsize > v9f->iounit)
		rsize = v9f->iounit;

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

		result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall);

		if (result < 0) {
			printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n",
			       result);

			kfree(fcall);
			return total;
		} else
			*offset += result;

		n = copy_to_user(data, fcall->params.rread.data, result);
		if (n) {
			dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n);
			kfree(fcall);
			return -EFAULT;
		}

		count -= result;
		data += result;
		total += result;

		kfree(fcall);

		if (result < rsize)
			break;
	} while (count);

	return total;
}

/**
 * v9fs_file_write - write to a file
 * @filep: 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)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *v9fid = filp->private_data;
	struct v9fs_fcall *fcall;
	int fid = v9fid->fid;
	int result = -EIO;
	int rsize = 0;
	int total = 0;
	char *buf;

	dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
		(int)*offset);
	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	if (v9fid->iounit != 0 && rsize > v9fid->iounit)
		rsize = v9fid->iounit;

	buf = kmalloc(v9ses->maxdata - V9FS_IOHDRSZ, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

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

		result = copy_from_user(buf, data, rsize);
		if (result) {
			dprintk(DEBUG_ERROR, "Problem copying from user\n");
			kfree(buf);
			return -EFAULT;
		}

		dump_data(buf, rsize);
		result = v9fs_t_write(v9ses, fid, *offset, rsize, buf, &fcall);
		if (result < 0) {
			eprintk(KERN_ERR, "error while writing: %s(%d)\n",
				FCALL_ERROR(fcall), result);
			kfree(fcall);
			kfree(buf);
			return result;
		} else
			*offset += result;

		kfree(fcall);
		fcall = NULL;

		if (result != rsize) {
			eprintk(KERN_ERR,
				"short write: v9fs_t_write returned %d\n",
				result);
			break;
		}

		count -= result;
		data += result;
		total += result;
	} while (count);

	kfree(buf);
	return total;
}

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,
};
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
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to:
	21	* Free Software Foundation
	22	* 51 Franklin Street, Fifth Floor
	23	* Boston, MA 02111-1301 USA
	24	*
	25	*/
	26
	27	#include <linux/module.h>
	28	#include <linux/errno.h>
	29	#include <linux/fs.h>
	30	#include <linux/file.h>
	31	#include <linux/stat.h>
	32	#include <linux/string.h>
	33	#include <linux/smp_lock.h>
	34	#include <linux/inet.h>
e69e7fe5 EVH	35	#include <linux/list.h>
	36	#include <asm/uaccess.h>
	37	#include <linux/idr.h>
	38
	39	#include "debug.h"
	40	#include "v9fs.h"
	41	#include "9p.h"
	42	#include "v9fs_vfs.h"
	43	#include "fid.h"
	44
	45	/**
	46	* v9fs_file_open - open a file (or directory)
	47	* @inode: inode to be opened
	48	* @file: file being opened
	49	*
	50	*/
	51
	52	int v9fs_file_open(struct inode inode, struct file file)
	53	{
	54	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
0b8dd177	55	struct v9fs_fid v9fid, fid;
e69e7fe5 EVH	56	struct v9fs_fcall *fcall = NULL;
	57	int open_mode = 0;
	58	unsigned int iounit = 0;
	59	int newfid = -1;
	60	long result = -1;
	61
0b8dd177 LI	62	dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file);
	63
	64	v9fid = v9fs_fid_get_created(file->f_dentry);
	65	if (!v9fid)
	66	v9fid = v9fs_fid_lookup(file->f_dentry);
e69e7fe5 EVH	67
e69e7fe5 EVH	68	if (!v9fid) {
e69e7fe5	69	dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n");
0b8dd177 LI	70	return -EBADF;
0b8dd177 LI	71	}
e69e7fe5	72
0b8dd177 LI	73	if (!v9fid->fidcreate) {
	74	fid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
	75	if (fid == NULL) {
	76	dprintk(DEBUG_ERROR, "Out of Memory\n");
	77	return -ENOMEM;
	78	}
e69e7fe5	79
0b8dd177 LI	80	fid->fidopen = 0;
	81	fid->fidcreate = 0;
	82	fid->fidclunked = 0;
	83	fid->iounit = 0;
	84	fid->v9ses = v9ses;
e69e7fe5 EVH	85
	86	newfid = v9fs_get_idpool(&v9ses->fidpool);
	87	if (newfid < 0) {
	88	eprintk(KERN_WARNING, "newfid fails!\n");
	89	return -ENOSPC;
	90	}
	91
	92	result =
0b8dd177 LI	93	v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, NULL);
0b8dd177 LI	94
e69e7fe5 EVH	95	if (result < 0) {
	96	v9fs_put_idpool(newfid, &v9ses->fidpool);
	97	dprintk(DEBUG_ERROR, "rewalk didn't work\n");
	98	return -EBADF;
	99	}
	100
0b8dd177 LI	101	fid->fid = newfid;
0b8dd177 LI	102	v9fid = fid;
e69e7fe5 EVH	103	/* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */
	104	/* translate open mode appropriately */
	105	open_mode = file->f_flags & 0x3;
	106
	107	if (file->f_flags & O_EXCL)
	108	open_mode \|= V9FS_OEXCL;
	109
	110	if (v9ses->extended) {
	111	if (file->f_flags & O_TRUNC)
	112	open_mode \|= V9FS_OTRUNC;
	113
	114	if (file->f_flags & O_APPEND)
	115	open_mode \|= V9FS_OAPPEND;
	116	}
	117
	118	result = v9fs_t_open(v9ses, newfid, open_mode, &fcall);
	119	if (result < 0) {
	120	dprintk(DEBUG_ERROR,
	121	"open failed, open_mode 0x%x: %s\n", open_mode,
	122	FCALL_ERROR(fcall));
	123	kfree(fcall);
	124	return result;
	125	}
	126
	127	iounit = fcall->params.ropen.iounit;
	128	kfree(fcall);
0b8dd177 LI	129	} else {
	130	/* create case */
	131	newfid = v9fid->fid;
	132	iounit = v9fid->iounit;
	133	v9fid->fidcreate = 0;
e69e7fe5 EVH	134	}
e69e7fe5 EVH	135
e69e7fe5 EVH	136	file->private_data = v9fid;
	137
	138	v9fid->rdir_pos = 0;
	139	v9fid->rdir_fcall = NULL;
	140	v9fid->fidopen = 1;
	141	v9fid->filp = file;
	142	v9fid->iounit = iounit;
	143
	144	return 0;
	145	}
	146
	147	/**
	148	* v9fs_file_lock - lock a file (or directory)
	149	* @inode: inode to be opened
	150	* @file: file being opened
	151	*
	152	* XXX - this looks like a local only lock, we should extend into 9P
	153	* by using open exclusive
	154	*/
	155
	156	static int v9fs_file_lock(struct file filp, int cmd, struct file_lock fl)
	157	{
	158	int res = 0;
	159	struct inode *inode = filp->f_dentry->d_inode;
	160
	161	dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
	162
	163	/* No mandatory locks */
	164	if ((inode->i_mode & (S_ISGID \| S_IXGRP)) == S_ISGID)
	165	return -ENOLCK;
	166
	167	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
	168	filemap_fdatawrite(inode->i_mapping);
	169	filemap_fdatawait(inode->i_mapping);
	170	invalidate_inode_pages(&inode->i_data);
	171	}
	172
	173	return res;
	174	}
	175
	176	/**
19cba8ab	177	* v9fs_file_read - read from a file
e69e7fe5 EVH	178	* @filep: file pointer to read
	179	* @data: data buffer to read data into
	180	* @count: size of buffer
	181	* @offset: offset at which to read data
	182	*
	183	*/
e69e7fe5	184	static ssize_t
19cba8ab LI	185	v9fs_file_read(struct file filp, char __user data, size_t count,
19cba8ab LI	186	loff_t * offset)
e69e7fe5 EVH	187	{
	188	struct inode *inode = filp->f_dentry->d_inode;
	189	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	190	struct v9fs_fid *v9f = filp->private_data;
	191	struct v9fs_fcall *fcall = NULL;
	192	int fid = v9f->fid;
	193	int rsize = 0;
	194	int result = 0;
	195	int total = 0;
19cba8ab	196	int n;
e69e7fe5 EVH	197
	198	dprintk(DEBUG_VFS, "\n");
	199
	200	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	201	if (v9f->iounit != 0 && rsize > v9f->iounit)
	202	rsize = v9f->iounit;
	203
	204	do {
	205	if (count < rsize)
	206	rsize = count;
	207
	208	result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall);
	209
	210	if (result < 0) {
	211	printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n",
	212	result);
	213
	214	kfree(fcall);
	215	return total;
	216	} else
	217	*offset += result;
	218
19cba8ab LI	219	n = copy_to_user(data, fcall->params.rread.data, result);
	220	if (n) {
	221	dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n);
	222	kfree(fcall);
	223	return -EFAULT;
	224	}
	225
e69e7fe5	226	count -= result;
19cba8ab	227	data += result;
e69e7fe5 EVH	228	total += result;
	229
	230	kfree(fcall);
	231
	232	if (result < rsize)
	233	break;
	234	} while (count);
	235
	236	return total;
	237	}
	238
	239	/**
19cba8ab	240	* v9fs_file_write - write to a file
e69e7fe5 EVH	241	* @filep: file pointer to write
	242	* @data: data buffer to write data from
	243	* @count: size of buffer
	244	* @offset: offset at which to write data
	245	*
	246	*/
	247
	248	static ssize_t
19cba8ab LI	249	v9fs_file_write(struct file filp, const char __user data,
19cba8ab LI	250	size_t count, loff_t * offset)
e69e7fe5 EVH	251	{
	252	struct inode *inode = filp->f_dentry->d_inode;
	253	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	254	struct v9fs_fid *v9fid = filp->private_data;
	255	struct v9fs_fcall *fcall;
	256	int fid = v9fid->fid;
	257	int result = -EIO;
	258	int rsize = 0;
	259	int total = 0;
19cba8ab	260	char *buf;
e69e7fe5	261
19cba8ab	262	dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
e69e7fe5 EVH	263	(int)*offset);
	264	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	265	if (v9fid->iounit != 0 && rsize > v9fid->iounit)
	266	rsize = v9fid->iounit;
	267
19cba8ab LI	268	buf = kmalloc(v9ses->maxdata - V9FS_IOHDRSZ, GFP_KERNEL);
	269	if (!buf)
	270	return -ENOMEM;
e69e7fe5 EVH	271
	272	do {
	273	if (count < rsize)
	274	rsize = count;
	275
19cba8ab LI	276	result = copy_from_user(buf, data, rsize);
	277	if (result) {
	278	dprintk(DEBUG_ERROR, "Problem copying from user\n");
	279	kfree(buf);
	280	return -EFAULT;
	281	}
	282
	283	dump_data(buf, rsize);
	284	result = v9fs_t_write(v9ses, fid, *offset, rsize, buf, &fcall);
e69e7fe5 EVH	285	if (result < 0) {
	286	eprintk(KERN_ERR, "error while writing: %s(%d)\n",
	287	FCALL_ERROR(fcall), result);
	288	kfree(fcall);
19cba8ab	289	kfree(buf);
e69e7fe5 EVH	290	return result;
	291	} else
	292	*offset += result;
	293
	294	kfree(fcall);
19cba8ab	295	fcall = NULL;
e69e7fe5 EVH	296
	297	if (result != rsize) {
	298	eprintk(KERN_ERR,
	299	"short write: v9fs_t_write returned %d\n",
	300	result);
	301	break;
	302	}
	303
	304	count -= result;
19cba8ab	305	data += result;
e69e7fe5 EVH	306	total += result;
	307	} while (count);
	308
19cba8ab	309	kfree(buf);
e69e7fe5 EVH	310	return total;
	311	}
	312
e69e7fe5 EVH	313	struct file_operations v9fs_file_operations = {
	314	.llseek = generic_file_llseek,
	315	.read = v9fs_file_read,
	316	.write = v9fs_file_write,
	317	.open = v9fs_file_open,
	318	.release = v9fs_dir_release,
	319	.lock = v9fs_file_lock,
	320	};