xref: /openbmc/linux/fs/9p/vfs_dir.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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 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>
35 #include <linux/idr.h>
36 
37 #include "debug.h"
38 #include "v9fs.h"
39 #include "9p.h"
40 #include "v9fs_vfs.h"
41 #include "conv.h"
42 #include "fid.h"
43 
44 /**
45  * dt_type - return file type
46  * @mistat: mistat structure
47  *
48  */
49 
50 static inline int dt_type(struct v9fs_stat *mistat)
51 {
52 	unsigned long perm = mistat->mode;
53 	int rettype = DT_REG;
54 
55 	if (perm & V9FS_DMDIR)
56 		rettype = DT_DIR;
57 	if (perm & V9FS_DMSYMLINK)
58 		rettype = DT_LNK;
59 
60 	return rettype;
61 }
62 
63 /**
64  * v9fs_dir_readdir - read a directory
65  * @filep: opened file structure
66  * @dirent: directory structure ???
67  * @filldir: function to populate directory structure ???
68  *
69  */
70 
71 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
72 {
73 	struct v9fs_fcall *fcall = NULL;
74 	struct inode *inode = filp->f_dentry->d_inode;
75 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
76 	struct v9fs_fid *file = filp->private_data;
77 	unsigned int i, n;
78 	int fid = -1;
79 	int ret = 0;
80 	struct v9fs_stat *mi = NULL;
81 	int over = 0;
82 
83 	dprintk(DEBUG_VFS, "name %s\n", filp->f_dentry->d_name.name);
84 
85 	fid = file->fid;
86 
87 	mi = kmalloc(v9ses->maxdata, GFP_KERNEL);
88 	if (!mi)
89 		return -ENOMEM;
90 
91 	if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) {
92 		kfree(file->rdir_fcall);
93 		file->rdir_fcall = NULL;
94 	}
95 
96 	if (file->rdir_fcall) {
97 		n = file->rdir_fcall->params.rread.count;
98 		i = file->rdir_fpos;
99 		while (i < n) {
100 			int s = v9fs_deserialize_stat(v9ses,
101 				  file->rdir_fcall->params.rread.data + i,
102 			          n - i, mi, v9ses->maxdata);
103 
104 			if (s == 0) {
105 				dprintk(DEBUG_ERROR,
106 					"error while deserializing mistat\n");
107 				ret = -EIO;
108 				goto FreeStructs;
109 			}
110 
111 			over = filldir(dirent, mi->name, strlen(mi->name),
112 				    filp->f_pos, v9fs_qid2ino(&mi->qid),
113 				    dt_type(mi));
114 
115 			if (over) {
116 				file->rdir_fpos = i;
117 				file->rdir_pos = filp->f_pos;
118 				break;
119 			}
120 
121 			i += s;
122 			filp->f_pos += s;
123 		}
124 
125 		if (!over) {
126 			kfree(file->rdir_fcall);
127 			file->rdir_fcall = NULL;
128 		}
129 	}
130 
131 	while (!over) {
132 		ret = v9fs_t_read(v9ses, fid, filp->f_pos,
133 					    v9ses->maxdata-V9FS_IOHDRSZ, &fcall);
134 		if (ret < 0) {
135 			dprintk(DEBUG_ERROR, "error while reading: %d: %p\n",
136 				ret, fcall);
137 			goto FreeStructs;
138 		} else if (ret == 0)
139 			break;
140 
141 		n = ret;
142 		i = 0;
143 		while (i < n) {
144 			int s = v9fs_deserialize_stat(v9ses,
145 			          fcall->params.rread.data + i, n - i, mi,
146 			          v9ses->maxdata);
147 
148 			if (s == 0) {
149 				dprintk(DEBUG_ERROR,
150 					"error while deserializing mistat\n");
151 				return -EIO;
152 			}
153 
154 			over = filldir(dirent, mi->name, strlen(mi->name),
155 				    filp->f_pos, v9fs_qid2ino(&mi->qid),
156 				    dt_type(mi));
157 
158 			if (over) {
159 				file->rdir_fcall = fcall;
160 				file->rdir_fpos = i;
161 				file->rdir_pos = filp->f_pos;
162 				fcall = NULL;
163 				break;
164 			}
165 
166 			i += s;
167 			filp->f_pos += s;
168 		}
169 
170 		kfree(fcall);
171 	}
172 
173       FreeStructs:
174 	kfree(fcall);
175 	kfree(mi);
176 	return ret;
177 }
178 
179 /**
180  * v9fs_dir_release - close a directory
181  * @inode: inode of the directory
182  * @filp: file pointer to a directory
183  *
184  */
185 
186 int v9fs_dir_release(struct inode *inode, struct file *filp)
187 {
188 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
189 	struct v9fs_fid *fid = filp->private_data;
190 	int fidnum = -1;
191 
192 	dprintk(DEBUG_VFS, "inode: %p filp: %p fid: %d\n", inode, filp,
193 		fid->fid);
194 	fidnum = fid->fid;
195 
196 	filemap_fdatawrite(inode->i_mapping);
197 	filemap_fdatawait(inode->i_mapping);
198 
199 	if (fidnum >= 0) {
200 		dprintk(DEBUG_VFS, "fidopen: %d v9f->fid: %d\n", fid->fidopen,
201 			fid->fid);
202 
203 		if (v9fs_t_clunk(v9ses, fidnum, NULL))
204 			dprintk(DEBUG_ERROR, "clunk failed\n");
205 
206 		v9fs_put_idpool(fid->fid, &v9ses->fidpool);
207 
208 		kfree(fid->rdir_fcall);
209 		kfree(fid);
210 
211 		filp->private_data = NULL;
212 	}
213 
214 	d_drop(filp->f_dentry);
215 	return 0;
216 }
217 
218 struct file_operations v9fs_dir_operations = {
219 	.read = generic_read_dir,
220 	.readdir = v9fs_dir_readdir,
221 	.open = v9fs_file_open,
222 	.release = v9fs_dir_release,
223 };
224