[linux-2.6-block.git] / fs / 9p / vfs_dir.c

/*
 * linux/fs/9p/vfs_dir.c
 *
 * This file contains vfs directory ops for the 9P2000 protocol.
 *
 *  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/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

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

/**
 * struct p9_rdir - readdir accounting
 * @mutex: mutex protecting readdir
 * @head: start offset of current dirread buffer
 * @tail: end offset of current dirread buffer
 * @buf: dirread buffer
 *
 * private structure for keeping track of readdir
 * allocated on demand
 */

struct p9_rdir {
	struct mutex mutex;
	int head;
	int tail;
	uint8_t *buf;
};

/**
 * dt_type - return file type
 * @mistat: mistat structure
 *
 */

static inline int dt_type(struct p9_wstat *mistat)
{
	unsigned long perm = mistat->mode;
	int rettype = DT_REG;

	if (perm & P9_DMDIR)
		rettype = DT_DIR;
	if (perm & P9_DMSYMLINK)
		rettype = DT_LNK;

	return rettype;
}

static void p9stat_init(struct p9_wstat *stbuf)
{
	stbuf->name  = NULL;
	stbuf->uid   = NULL;
	stbuf->gid   = NULL;
	stbuf->muid  = NULL;
	stbuf->extension = NULL;
}

/**
 * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
 * @filp: opened file structure
 * @buflen: Length in bytes of buffer to allocate
 *
 */

static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
{
	struct p9_rdir *rdir;
	struct p9_fid *fid;
	int err = 0;

	fid = filp->private_data;
	if (!fid->rdir) {
		rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);

		if (rdir == NULL) {
			err = -ENOMEM;
			goto exit;
		}
		spin_lock(&filp->f_dentry->d_lock);
		if (!fid->rdir) {
			rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
			mutex_init(&rdir->mutex);
			rdir->head = rdir->tail = 0;
			fid->rdir = (void *) rdir;
			rdir = NULL;
		}
		spin_unlock(&filp->f_dentry->d_lock);
		kfree(rdir);
	}
exit:
	return err;
}

/**
 * v9fs_dir_readdir - read a directory
 * @filp: opened file structure
 * @dirent: directory structure ???
 * @filldir: function to populate directory structure ???
 *
 */

static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	int over;
	struct p9_wstat st;
	int err = 0;
	struct p9_fid *fid;
	int buflen;
	int reclen = 0;
	struct p9_rdir *rdir;

	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	fid = filp->private_data;

	buflen = fid->clnt->msize - P9_IOHDRSZ;

	err = v9fs_alloc_rdir_buf(filp, buflen);
	if (err)
		goto exit;
	rdir = (struct p9_rdir *) fid->rdir;

	err = mutex_lock_interruptible(&rdir->mutex);
	if (err)
		return err;
	while (err == 0) {
		if (rdir->tail == rdir->head) {
			err = v9fs_file_readn(filp, rdir->buf, NULL,
							buflen, filp->f_pos);
			if (err <= 0)
				goto unlock_and_exit;

			rdir->head = 0;
			rdir->tail = err;
		}
		while (rdir->head < rdir->tail) {
			p9stat_init(&st);
			err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
					  rdir->tail - rdir->head, &st);
			if (err) {
				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
				err = -EIO;
				p9stat_free(&st);
				goto unlock_and_exit;
			}
			reclen = st.size+2;

			over = filldir(dirent, st.name, strlen(st.name),
			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));

			p9stat_free(&st);

			if (over) {
				err = 0;
				goto unlock_and_exit;
			}
			rdir->head += reclen;
			filp->f_pos += reclen;
		}
	}

unlock_and_exit:
	mutex_unlock(&rdir->mutex);
exit:
	return err;
}

/**
 * v9fs_dir_readdir_dotl - read a directory
 * @filp: opened file structure
 * @dirent: buffer to fill dirent structures
 * @filldir: function to populate dirent structures
 *
 */
static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
						filldir_t filldir)
{
	int over;
	int err = 0;
	struct p9_fid *fid;
	int buflen;
	struct p9_rdir *rdir;
	struct p9_dirent curdirent;
	u64 oldoffset = 0;

	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	fid = filp->private_data;

	buflen = fid->clnt->msize - P9_READDIRHDRSZ;

	err = v9fs_alloc_rdir_buf(filp, buflen);
	if (err)
		goto exit;
	rdir = (struct p9_rdir *) fid->rdir;

	err = mutex_lock_interruptible(&rdir->mutex);
	if (err)
		return err;

	while (err == 0) {
		if (rdir->tail == rdir->head) {
			err = p9_client_readdir(fid, rdir->buf, buflen,
						filp->f_pos);
			if (err <= 0)
				goto unlock_and_exit;

			rdir->head = 0;
			rdir->tail = err;
		}

		while (rdir->head < rdir->tail) {

			err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
					    rdir->tail - rdir->head,
					    &curdirent);
			if (err < 0) {
				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
				err = -EIO;
				goto unlock_and_exit;
			}

			/* d_off in dirent structure tracks the offset into
			 * the next dirent in the dir. However, filldir()
			 * expects offset into the current dirent. Hence
			 * while calling filldir send the offset from the
			 * previous dirent structure.
			 */
			over = filldir(dirent, curdirent.d_name,
					strlen(curdirent.d_name),
					oldoffset, v9fs_qid2ino(&curdirent.qid),
					curdirent.d_type);
			oldoffset = curdirent.d_off;

			if (over) {
				err = 0;
				goto unlock_and_exit;
			}

			filp->f_pos = curdirent.d_off;
			rdir->head += err;
		}
	}

unlock_and_exit:
	mutex_unlock(&rdir->mutex);
exit:
	return err;
}


/**
 * v9fs_dir_release - close a directory
 * @inode: inode of the directory
 * @filp: file pointer to a directory
 *
 */

int v9fs_dir_release(struct inode *inode, struct file *filp)
{
	struct p9_fid *fid;

	fid = filp->private_data;
	P9_DPRINTK(P9_DEBUG_VFS,
			"v9fs_dir_release: inode: %p filp: %p fid: %d\n",
			inode, filp, fid ? fid->fid : -1);
	if (fid)
		p9_client_clunk(fid);
	return 0;
}

const struct file_operations v9fs_dir_operations = {
	.read = generic_read_dir,
	.llseek = generic_file_llseek,
	.readdir = v9fs_dir_readdir,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
};

const struct file_operations v9fs_dir_operations_dotl = {
	.read = generic_read_dir,
	.llseek = generic_file_llseek,
	.readdir = v9fs_dir_readdir_dotl,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
        .fsync = v9fs_file_fsync_dotl,
};
Commit	Line	Data
e69e7fe5 EVH	1	/*
	2	* linux/fs/9p/vfs_dir.c
	3	*
	4	* This file contains vfs directory ops for the 9P2000 protocol.
	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>
	29	#include <linux/file.h>
	30	#include <linux/stat.h>
	31	#include <linux/string.h>
914e2637	32	#include <linux/sched.h>
e69e7fe5 EVH	33	#include <linux/inet.h>
e69e7fe5 EVH	34	#include <linux/idr.h>
5a0e3ad6	35	#include <linux/slab.h>
bd238fb4 LI	36	#include <net/9p/9p.h>
bd238fb4 LI	37	#include <net/9p/client.h>
e69e7fe5	38
e69e7fe5	39	#include "v9fs.h"
531b1094	40	#include "v9fs_vfs.h"
e69e7fe5 EVH	41	#include "fid.h"
e69e7fe5 EVH	42
3e2796a9 EVH	43	/**
	44	* struct p9_rdir - readdir accounting
	45	* @mutex: mutex protecting readdir
	46	* @head: start offset of current dirread buffer
	47	* @tail: end offset of current dirread buffer
	48	* @buf: dirread buffer
	49	*
	50	* private structure for keeping track of readdir
	51	* allocated on demand
	52	*/
	53
	54	struct p9_rdir {
	55	struct mutex mutex;
	56	int head;
	57	int tail;
	58	uint8_t *buf;
	59	};
	60
e69e7fe5 EVH	61	/**
	62	* dt_type - return file type
	63	* @mistat: mistat structure
	64	*
	65	*/
	66
02da398b	67	static inline int dt_type(struct p9_wstat *mistat)
e69e7fe5 EVH	68	{
	69	unsigned long perm = mistat->mode;
	70	int rettype = DT_REG;
	71
bd238fb4	72	if (perm & P9_DMDIR)
e69e7fe5	73	rettype = DT_DIR;
bd238fb4	74	if (perm & P9_DMSYMLINK)
e69e7fe5 EVH	75	rettype = DT_LNK;
	76
	77	return rettype;
	78	}
	79
fae4528b AK	80	static void p9stat_init(struct p9_wstat *stbuf)
	81	{
	82	stbuf->name = NULL;
	83	stbuf->uid = NULL;
	84	stbuf->gid = NULL;
	85	stbuf->muid = NULL;
	86	stbuf->extension = NULL;
	87	}
	88
e69e7fe5	89	/**
7751bdb3	90	* v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
ee443996	91	* @filp: opened file structure
7751bdb3	92	* @buflen: Length in bytes of buffer to allocate
e69e7fe5 EVH	93	*
	94	*/
	95
7751bdb3	96	static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
e69e7fe5	97	{
3e2796a9	98	struct p9_rdir *rdir;
7751bdb3 SK	99	struct p9_fid *fid;
7751bdb3 SK	100	int err = 0;
bd238fb4	101
bd238fb4	102	fid = filp->private_data;
3e2796a9 EVH	103	if (!fid->rdir) {
	104	rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
	105
	106	if (rdir == NULL) {
	107	err = -ENOMEM;
	108	goto exit;
	109	}
	110	spin_lock(&filp->f_dentry->d_lock);
	111	if (!fid->rdir) {
	112	rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
	113	mutex_init(&rdir->mutex);
	114	rdir->head = rdir->tail = 0;
	115	fid->rdir = (void *) rdir;
	116	rdir = NULL;
	117	}
	118	spin_unlock(&filp->f_dentry->d_lock);
	119	kfree(rdir);
	120	}
7751bdb3 SK	121	exit:
	122	return err;
	123	}
	124
	125	/**
	126	* v9fs_dir_readdir - read a directory
	127	* @filp: opened file structure
	128	* @dirent: directory structure ???
	129	* @filldir: function to populate directory structure ???
	130	*
	131	*/
	132
	133	static int v9fs_dir_readdir(struct file filp, void dirent, filldir_t filldir)
	134	{
	135	int over;
	136	struct p9_wstat st;
	137	int err = 0;
	138	struct p9_fid *fid;
	139	int buflen;
	140	int reclen = 0;
	141	struct p9_rdir *rdir;
	142
	143	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	144	fid = filp->private_data;
	145
	146	buflen = fid->clnt->msize - P9_IOHDRSZ;
	147
	148	err = v9fs_alloc_rdir_buf(filp, buflen);
	149	if (err)
	150	goto exit;
3e2796a9 EVH	151	rdir = (struct p9_rdir *) fid->rdir;
	152
	153	err = mutex_lock_interruptible(&rdir->mutex);
85a770a8 DC	154	if (err)
85a770a8 DC	155	return err;
3e2796a9 EVH	156	while (err == 0) {
	157	if (rdir->tail == rdir->head) {
	158	err = v9fs_file_readn(filp, rdir->buf, NULL,
	159	buflen, filp->f_pos);
	160	if (err <= 0)
	161	goto unlock_and_exit;
	162
	163	rdir->head = 0;
	164	rdir->tail = err;
	165	}
3e2796a9	166	while (rdir->head < rdir->tail) {
fae4528b	167	p9stat_init(&st);
348b5901 AK	168	err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
348b5901 AK	169	rdir->tail - rdir->head, &st);
02da398b EVH	170	if (err) {
02da398b EVH	171	P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
06b55b46	172	err = -EIO;
02da398b	173	p9stat_free(&st);
3e2796a9	174	goto unlock_and_exit;
06b55b46	175	}
3e2796a9	176	reclen = st.size+2;
06b55b46	177
02da398b	178	over = filldir(dirent, st.name, strlen(st.name),
06b55b46 EVH	179	filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
06b55b46 EVH	180
02da398b	181	p9stat_free(&st);
06b55b46 EVH	182
	183	if (over) {
	184	err = 0;
3e2796a9	185	goto unlock_and_exit;
06b55b46	186	}
3e2796a9 EVH	187	rdir->head += reclen;
3e2796a9 EVH	188	filp->f_pos += reclen;
06b55b46	189	}
e69e7fe5 EVH	190	}
e69e7fe5 EVH	191
3e2796a9 EVH	192	unlock_and_exit:
	193	mutex_unlock(&rdir->mutex);
	194	exit:
06b55b46	195	return err;
e69e7fe5 EVH	196	}
e69e7fe5 EVH	197
7751bdb3 SK	198	/**
	199	* v9fs_dir_readdir_dotl - read a directory
	200	* @filp: opened file structure
	201	* @dirent: buffer to fill dirent structures
	202	* @filldir: function to populate dirent structures
	203	*
	204	*/
	205	static int v9fs_dir_readdir_dotl(struct file filp, void dirent,
	206	filldir_t filldir)
	207	{
	208	int over;
	209	int err = 0;
	210	struct p9_fid *fid;
	211	int buflen;
	212	struct p9_rdir *rdir;
	213	struct p9_dirent curdirent;
	214	u64 oldoffset = 0;
	215
	216	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	217	fid = filp->private_data;
	218
	219	buflen = fid->clnt->msize - P9_READDIRHDRSZ;
	220
	221	err = v9fs_alloc_rdir_buf(filp, buflen);
	222	if (err)
	223	goto exit;
	224	rdir = (struct p9_rdir *) fid->rdir;
	225
	226	err = mutex_lock_interruptible(&rdir->mutex);
	227	if (err)
	228	return err;
	229
	230	while (err == 0) {
	231	if (rdir->tail == rdir->head) {
	232	err = p9_client_readdir(fid, rdir->buf, buflen,
abfa034e	233	filp->f_pos);
7751bdb3 SK	234	if (err <= 0)
	235	goto unlock_and_exit;
	236
	237	rdir->head = 0;
	238	rdir->tail = err;
	239	}
	240
	241	while (rdir->head < rdir->tail) {
	242
348b5901 AK	243	err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
	244	rdir->tail - rdir->head,
	245	&curdirent);
7751bdb3 SK	246	if (err < 0) {
	247	P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
	248	err = -EIO;
	249	goto unlock_and_exit;
	250	}
	251
	252	/* d_off in dirent structure tracks the offset into
	253	* the next dirent in the dir. However, filldir()
	254	* expects offset into the current dirent. Hence
	255	* while calling filldir send the offset from the
	256	* previous dirent structure.
	257	*/
	258	over = filldir(dirent, curdirent.d_name,
	259	strlen(curdirent.d_name),
	260	oldoffset, v9fs_qid2ino(&curdirent.qid),
	261	curdirent.d_type);
	262	oldoffset = curdirent.d_off;
	263
	264	if (over) {
	265	err = 0;
	266	goto unlock_and_exit;
	267	}
	268
	269	filp->f_pos = curdirent.d_off;
	270	rdir->head += err;
	271	}
	272	}
	273
	274	unlock_and_exit:
	275	mutex_unlock(&rdir->mutex);
	276	exit:
	277	return err;
	278	}
	279
bd238fb4	280
e69e7fe5 EVH	281	/**
	282	* v9fs_dir_release - close a directory
	283	* @inode: inode of the directory
	284	* @filp: file pointer to a directory
	285	*
	286	*/
	287
	288	int v9fs_dir_release(struct inode inode, struct file filp)
	289	{
bd238fb4	290	struct p9_fid *fid;
e69e7fe5	291
bd238fb4 LI	292	fid = filp->private_data;
bd238fb4 LI	293	P9_DPRINTK(P9_DEBUG_VFS,
62726a7a	294	"v9fs_dir_release: inode: %p filp: %p fid: %d\n",
62726a7a	295	inode, filp, fid ? fid->fid : -1);
62726a7a	296	if (fid)
62726a7a	297	p9_client_clunk(fid);
e69e7fe5 EVH	298	return 0;
	299	}
	300
4b6f5d20	301	const struct file_operations v9fs_dir_operations = {
e69e7fe5	302	.read = generic_read_dir,
59af1584	303	.llseek = generic_file_llseek,
e69e7fe5 EVH	304	.readdir = v9fs_dir_readdir,
	305	.open = v9fs_file_open,
	306	.release = v9fs_dir_release,
	307	};
9b6533c9 SK	308
	309	const struct file_operations v9fs_dir_operations_dotl = {
	310	.read = generic_read_dir,
	311	.llseek = generic_file_llseek,
7751bdb3	312	.readdir = v9fs_dir_readdir_dotl,
9b6533c9 SK	313	.open = v9fs_file_open,
9b6533c9 SK	314	.release = v9fs_dir_release,
b165d601	315	.fsync = v9fs_file_fsync_dotl,
9b6533c9	316	};