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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * QNX4 file system, Linux implementation.
3 *
4 * Version : 0.2.1
5 *
6 * Using parts of the xiafs filesystem.
7 *
8 * History :
9 *
10 * 01-06-1998 by Richard Frowijn : first release.
11 * 21-06-1998 by Frank Denis : dcache support, fixed error codes.
12 * 04-07-1998 by Frank Denis : first step for rmdir/unlink.
13 */
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/time.h>
16#include <linux/fs.h>
17#include <linux/qnx4_fs.h>
18#include <linux/kernel.h>
19#include <linux/string.h>
20#include <linux/stat.h>
21#include <linux/fcntl.h>
22#include <linux/errno.h>
23#include <linux/smp_lock.h>
24#include <linux/buffer_head.h>
25
26
27/*
28 * check if the filename is correct. For some obscure reason, qnx writes a
29 * new file twice in the directory entry, first with all possible options at 0
30 * and for a second time the way it is, they want us not to access the qnx
31 * filesystem when whe are using linux.
32 */
33static int qnx4_match(int len, const char *name,
34 struct buffer_head *bh, unsigned long *offset)
35{
36 struct qnx4_inode_entry *de;
37 int namelen, thislen;
38
39 if (bh == NULL) {
40 printk("qnx4: matching unassigned buffer !\n");
41 return 0;
42 }
43 de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
44 *offset += QNX4_DIR_ENTRY_SIZE;
45 if ((de->di_status & QNX4_FILE_LINK) != 0) {
46 namelen = QNX4_NAME_MAX;
47 } else {
48 namelen = QNX4_SHORT_NAME_MAX;
49 }
50 /* "" means "." ---> so paths like "/usr/lib//libc.a" work */
51 if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) {
52 return 1;
53 }
54 thislen = strlen( de->di_fname );
55 if ( thislen > namelen )
56 thislen = namelen;
57 if (len != thislen) {
58 return 0;
59 }
60 if (strncmp(name, de->di_fname, len) == 0) {
61 if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
62 return 1;
63 }
64 }
65 return 0;
66}
67
68static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
69 const char *name, struct qnx4_inode_entry **res_dir, int *ino)
70{
71 unsigned long block, offset, blkofs;
72 struct buffer_head *bh;
73
74 *res_dir = NULL;
75 if (!dir->i_sb) {
76 printk("qnx4: no superblock on dir.\n");
77 return NULL;
78 }
79 bh = NULL;
80 block = offset = blkofs = 0;
81 while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
82 if (!bh) {
83 bh = qnx4_bread(dir, blkofs, 0);
84 if (!bh) {
85 blkofs++;
86 continue;
87 }
88 }
89 *res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
90 if (qnx4_match(len, name, bh, &offset)) {
91 block = qnx4_block_map( dir, blkofs );
92 *ino = block * QNX4_INODES_PER_BLOCK +
93 (offset / QNX4_DIR_ENTRY_SIZE) - 1;
94 return bh;
95 }
96 if (offset < bh->b_size) {
97 continue;
98 }
99 brelse(bh);
100 bh = NULL;
101 offset = 0;
102 blkofs++;
103 }
104 brelse(bh);
105 *res_dir = NULL;
106 return NULL;
107}
108
109struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
110{
111 int ino;
112 struct qnx4_inode_entry *de;
113 struct qnx4_link_info *lnk;
114 struct buffer_head *bh;
115 const char *name = dentry->d_name.name;
116 int len = dentry->d_name.len;
117 struct inode *foundinode = NULL;
118
119 lock_kernel();
120 if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
121 goto out;
122 /* The entry is linked, let's get the real info */
123 if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
124 lnk = (struct qnx4_link_info *) de;
125 ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
126 QNX4_INODES_PER_BLOCK +
127 lnk->dl_inode_ndx;
128 }
129 brelse(bh);
130
David Howells2b7e5bc2008-02-07 00:15:45 -0800131 foundinode = qnx4_iget(dir->i_sb, ino);
132 if (IS_ERR(foundinode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 unlock_kernel();
David Howells2b7e5bc2008-02-07 00:15:45 -0800134 QNX4DEBUG(("qnx4: lookup->iget -> error %ld\n",
135 PTR_ERR(foundinode)));
136 return ERR_CAST(foundinode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 }
138out:
139 unlock_kernel();
140 d_add(dentry, foundinode);
141
142 return NULL;
143}
144
145#ifdef CONFIG_QNX4FS_RW
146int qnx4_create(struct inode *dir, struct dentry *dentry, int mode,
147 struct nameidata *nd)
148{
149 QNX4DEBUG(("qnx4: qnx4_create\n"));
150 if (dir == NULL) {
151 return -ENOENT;
152 }
153 return -ENOSPC;
154}
155
156int qnx4_rmdir(struct inode *dir, struct dentry *dentry)
157{
158 struct buffer_head *bh;
159 struct qnx4_inode_entry *de;
160 struct inode *inode;
161 int retval;
162 int ino;
163
164 QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name));
165 lock_kernel();
166 bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
167 &de, &ino);
168 if (bh == NULL) {
169 unlock_kernel();
170 return -ENOENT;
171 }
172 inode = dentry->d_inode;
173 if (inode->i_ino != ino) {
174 retval = -EIO;
175 goto end_rmdir;
176 }
177#if 0
178 if (!empty_dir(inode)) {
179 retval = -ENOTEMPTY;
180 goto end_rmdir;
181 }
182#endif
183 if (inode->i_nlink != 2) {
184 QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink));
185 }
186 QNX4DEBUG(("qnx4: deleting directory\n"));
187 de->di_status = 0;
188 memset(de->di_fname, 0, sizeof de->di_fname);
189 de->di_mode = 0;
190 mark_buffer_dirty(bh);
Dave Hansence71ec32006-09-30 23:29:06 -0700191 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 mark_inode_dirty(inode);
193 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700194 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 retval = 0;
196
197 end_rmdir:
198 brelse(bh);
199
200 unlock_kernel();
201 return retval;
202}
203
204int qnx4_unlink(struct inode *dir, struct dentry *dentry)
205{
206 struct buffer_head *bh;
207 struct qnx4_inode_entry *de;
208 struct inode *inode;
209 int retval;
210 int ino;
211
212 QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name));
213 lock_kernel();
214 bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
215 &de, &ino);
216 if (bh == NULL) {
217 unlock_kernel();
218 return -ENOENT;
219 }
220 inode = dentry->d_inode;
221 if (inode->i_ino != ino) {
222 retval = -EIO;
223 goto end_unlink;
224 }
225 retval = -EPERM;
226 if (!inode->i_nlink) {
227 QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
228 inode->i_sb->s_id,
229 inode->i_ino, inode->i_nlink));
230 inode->i_nlink = 1;
231 }
232 de->di_status = 0;
233 memset(de->di_fname, 0, sizeof de->di_fname);
234 de->di_mode = 0;
235 mark_buffer_dirty(bh);
236 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
237 mark_inode_dirty(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 inode->i_ctime = dir->i_ctime;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700239 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 retval = 0;
241
242end_unlink:
243 unlock_kernel();
244 brelse(bh);
245
246 return retval;
247}
248#endif