aboutsummaryrefslogtreecommitdiffstats
path: root/fs/9p/vfs_dir.c
blob: d61e3b28ce37a09caca5b5c40214b0e1ec109b22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
/*
 * 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_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;

	/* allocate rdir on demand */
	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);
	}
	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(rdir->buf + rdir->head,
						buflen - rdir->head, &st,
						fid->clnt->proto_version);
			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_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,
			"inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
	filemap_write_and_wait(inode->i_mapping);
	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,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
};

Privacy Policy