xref: /openbmc/linux/fs/9p/vfs_dir.c (revision 64c70b1c)
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
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
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>
32 #include <linux/sched.h>
33 #include <linux/inet.h>
34 #include <linux/idr.h>
35 
36 #include "debug.h"
37 #include "v9fs.h"
38 #include "9p.h"
39 #include "conv.h"
40 #include "v9fs_vfs.h"
41 #include "fid.h"
42 
43 /**
44  * dt_type - return file type
45  * @mistat: mistat structure
46  *
47  */
48 
49 static inline int dt_type(struct v9fs_stat *mistat)
50 {
51 	unsigned long perm = mistat->mode;
52 	int rettype = DT_REG;
53 
54 	if (perm & V9FS_DMDIR)
55 		rettype = DT_DIR;
56 	if (perm & V9FS_DMSYMLINK)
57 		rettype = DT_LNK;
58 
59 	return rettype;
60 }
61 
62 /**
63  * v9fs_dir_readdir - read a directory
64  * @filep: opened file structure
65  * @dirent: directory structure ???
66  * @filldir: function to populate directory structure ???
67  *
68  */
69 
70 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
71 {
72 	struct v9fs_fcall *fcall = NULL;
73 	struct inode *inode = filp->f_path.dentry->d_inode;
74 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
75 	struct v9fs_fid *file = filp->private_data;
76 	unsigned int i, n, s;
77 	int fid = -1;
78 	int ret = 0;
79 	struct v9fs_stat stat;
80 	int over = 0;
81 
82 	dprintk(DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
83 
84 	fid = file->fid;
85 
86 	if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) {
87 		kfree(file->rdir_fcall);
88 		file->rdir_fcall = NULL;
89 	}
90 
91 	if (file->rdir_fcall) {
92 		n = file->rdir_fcall->params.rread.count;
93 		i = file->rdir_fpos;
94 		while (i < n) {
95 			s = v9fs_deserialize_stat(
96 				file->rdir_fcall->params.rread.data + i,
97 				n - i, &stat, v9ses->extended);
98 
99 			if (s == 0) {
100 				dprintk(DEBUG_ERROR,
101 					"error while deserializing stat\n");
102 				ret = -EIO;
103 				goto FreeStructs;
104 			}
105 
106 			over = filldir(dirent, stat.name.str, stat.name.len,
107 				    filp->f_pos, v9fs_qid2ino(&stat.qid),
108 				    dt_type(&stat));
109 
110 			if (over) {
111 				file->rdir_fpos = i;
112 				file->rdir_pos = filp->f_pos;
113 				break;
114 			}
115 
116 			i += s;
117 			filp->f_pos += s;
118 		}
119 
120 		if (!over) {
121 			kfree(file->rdir_fcall);
122 			file->rdir_fcall = NULL;
123 		}
124 	}
125 
126 	while (!over) {
127 		ret = v9fs_t_read(v9ses, fid, filp->f_pos,
128 			v9ses->maxdata-V9FS_IOHDRSZ, &fcall);
129 		if (ret < 0) {
130 			dprintk(DEBUG_ERROR, "error while reading: %d: %p\n",
131 				ret, fcall);
132 			goto FreeStructs;
133 		} else if (ret == 0)
134 			break;
135 
136 		n = ret;
137 		i = 0;
138 		while (i < n) {
139 			s = v9fs_deserialize_stat(fcall->params.rread.data + i,
140 				n - i, &stat, v9ses->extended);
141 
142 			if (s == 0) {
143 				dprintk(DEBUG_ERROR,
144 					"error while deserializing stat\n");
145 				return -EIO;
146 			}
147 
148 			over = filldir(dirent, stat.name.str, stat.name.len,
149 				    filp->f_pos, v9fs_qid2ino(&stat.qid),
150 				    dt_type(&stat));
151 
152 			if (over) {
153 				file->rdir_fcall = fcall;
154 				file->rdir_fpos = i;
155 				file->rdir_pos = filp->f_pos;
156 				fcall = NULL;
157 				break;
158 			}
159 
160 			i += s;
161 			filp->f_pos += s;
162 		}
163 
164 		kfree(fcall);
165 	}
166 
167       FreeStructs:
168 	kfree(fcall);
169 	return ret;
170 }
171 
172 /**
173  * v9fs_dir_release - close a directory
174  * @inode: inode of the directory
175  * @filp: file pointer to a directory
176  *
177  */
178 
179 int v9fs_dir_release(struct inode *inode, struct file *filp)
180 {
181 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
182 	struct v9fs_fid *fid = filp->private_data;
183 	int fidnum = -1;
184 
185 	dprintk(DEBUG_VFS, "inode: %p filp: %p fid: %d\n", inode, filp,
186 		fid->fid);
187 	fidnum = fid->fid;
188 
189 	filemap_write_and_wait(inode->i_mapping);
190 
191 	if (fidnum >= 0) {
192 		dprintk(DEBUG_VFS, "fidopen: %d v9f->fid: %d\n", fid->fidopen,
193 			fid->fid);
194 
195 		if (v9fs_t_clunk(v9ses, fidnum))
196 			dprintk(DEBUG_ERROR, "clunk failed\n");
197 
198 		kfree(fid->rdir_fcall);
199 		kfree(fid);
200 
201 		filp->private_data = NULL;
202 	}
203 
204 	return 0;
205 }
206 
207 const struct file_operations v9fs_dir_operations = {
208 	.read = generic_read_dir,
209 	.readdir = v9fs_dir_readdir,
210 	.open = v9fs_file_open,
211 	.release = v9fs_dir_release,
212 };
213