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1/*
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
15#include <linux/buffer_head.h>
16#include "qnx4.h"
17
18
19/*
20 * check if the filename is correct. For some obscure reason, qnx writes a
21 * new file twice in the directory entry, first with all possible options at 0
22 * and for a second time the way it is, they want us not to access the qnx
23 * filesystem when whe are using linux.
24 */
25static int qnx4_match(int len, const char *name,
26 struct buffer_head *bh, unsigned long *offset)
27{
28 struct qnx4_inode_entry *de;
29 int namelen, thislen;
30
31 if (bh == NULL) {
32 printk(KERN_WARNING "qnx4: matching unassigned buffer !\n");
33 return 0;
34 }
35 de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
36 *offset += QNX4_DIR_ENTRY_SIZE;
37 if ((de->di_status & QNX4_FILE_LINK) != 0) {
38 namelen = QNX4_NAME_MAX;
39 } else {
40 namelen = QNX4_SHORT_NAME_MAX;
41 }
42 thislen = strlen( de->di_fname );
43 if ( thislen > namelen )
44 thislen = namelen;
45 if (len != thislen) {
46 return 0;
47 }
48 if (strncmp(name, de->di_fname, len) == 0) {
49 if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
50 return 1;
51 }
52 }
53 return 0;
54}
55
56static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
57 const char *name, struct qnx4_inode_entry **res_dir, int *ino)
58{
59 unsigned long block, offset, blkofs;
60 struct buffer_head *bh;
61
62 *res_dir = NULL;
63 bh = NULL;
64 block = offset = blkofs = 0;
65 while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
66 if (!bh) {
67 block = qnx4_block_map(dir, blkofs);
68 if (block)
69 bh = sb_bread(dir->i_sb, block);
70 if (!bh) {
71 blkofs++;
72 continue;
73 }
74 }
75 *res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
76 if (qnx4_match(len, name, bh, &offset)) {
77 *ino = block * QNX4_INODES_PER_BLOCK +
78 (offset / QNX4_DIR_ENTRY_SIZE) - 1;
79 return bh;
80 }
81 if (offset < bh->b_size) {
82 continue;
83 }
84 brelse(bh);
85 bh = NULL;
86 offset = 0;
87 blkofs++;
88 }
89 brelse(bh);
90 *res_dir = NULL;
91 return NULL;
92}
93
94struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
95{
96 int ino;
97 struct qnx4_inode_entry *de;
98 struct qnx4_link_info *lnk;
99 struct buffer_head *bh;
100 const char *name = dentry->d_name.name;
101 int len = dentry->d_name.len;
102 struct inode *foundinode = NULL;
103
104 if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
105 goto out;
106 /* The entry is linked, let's get the real info */
107 if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
108 lnk = (struct qnx4_link_info *) de;
109 ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
110 QNX4_INODES_PER_BLOCK +
111 lnk->dl_inode_ndx;
112 }
113 brelse(bh);
114
115 foundinode = qnx4_iget(dir->i_sb, ino);
116 if (IS_ERR(foundinode)) {
117 QNX4DEBUG((KERN_ERR "qnx4: lookup->iget -> error %ld\n",
118 PTR_ERR(foundinode)));
119 return ERR_CAST(foundinode);
120 }
121out:
122 d_add(dentry, foundinode);
123
124 return NULL;
125}
1/*
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
15#include <linux/buffer_head.h>
16#include "qnx4.h"
17
18
19/*
20 * check if the filename is correct. For some obscure reason, qnx writes a
21 * new file twice in the directory entry, first with all possible options at 0
22 * and for a second time the way it is, they want us not to access the qnx
23 * filesystem when whe are using linux.
24 */
25static int qnx4_match(int len, const char *name,
26 struct buffer_head *bh, unsigned long *offset)
27{
28 struct qnx4_inode_entry *de;
29 int namelen, thislen;
30
31 if (bh == NULL) {
32 printk(KERN_WARNING "qnx4: matching unassigned buffer !\n");
33 return 0;
34 }
35 de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
36 *offset += QNX4_DIR_ENTRY_SIZE;
37 if ((de->di_status & QNX4_FILE_LINK) != 0) {
38 namelen = QNX4_NAME_MAX;
39 } else {
40 namelen = QNX4_SHORT_NAME_MAX;
41 }
42 thislen = strlen( de->di_fname );
43 if ( thislen > namelen )
44 thislen = namelen;
45 if (len != thislen) {
46 return 0;
47 }
48 if (strncmp(name, de->di_fname, len) == 0) {
49 if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
50 return 1;
51 }
52 }
53 return 0;
54}
55
56static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
57 const char *name, struct qnx4_inode_entry **res_dir, int *ino)
58{
59 unsigned long block, offset, blkofs;
60 struct buffer_head *bh;
61
62 *res_dir = NULL;
63 if (!dir->i_sb) {
64 printk(KERN_WARNING "qnx4: no superblock on dir.\n");
65 return NULL;
66 }
67 bh = NULL;
68 block = offset = blkofs = 0;
69 while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
70 if (!bh) {
71 block = qnx4_block_map(dir, blkofs);
72 if (block)
73 bh = sb_bread(dir->i_sb, block);
74 if (!bh) {
75 blkofs++;
76 continue;
77 }
78 }
79 *res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
80 if (qnx4_match(len, name, bh, &offset)) {
81 *ino = block * QNX4_INODES_PER_BLOCK +
82 (offset / QNX4_DIR_ENTRY_SIZE) - 1;
83 return bh;
84 }
85 if (offset < bh->b_size) {
86 continue;
87 }
88 brelse(bh);
89 bh = NULL;
90 offset = 0;
91 blkofs++;
92 }
93 brelse(bh);
94 *res_dir = NULL;
95 return NULL;
96}
97
98struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
99{
100 int ino;
101 struct qnx4_inode_entry *de;
102 struct qnx4_link_info *lnk;
103 struct buffer_head *bh;
104 const char *name = dentry->d_name.name;
105 int len = dentry->d_name.len;
106 struct inode *foundinode = NULL;
107
108 if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
109 goto out;
110 /* The entry is linked, let's get the real info */
111 if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
112 lnk = (struct qnx4_link_info *) de;
113 ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
114 QNX4_INODES_PER_BLOCK +
115 lnk->dl_inode_ndx;
116 }
117 brelse(bh);
118
119 foundinode = qnx4_iget(dir->i_sb, ino);
120 if (IS_ERR(foundinode)) {
121 QNX4DEBUG((KERN_ERR "qnx4: lookup->iget -> error %ld\n",
122 PTR_ERR(foundinode)));
123 return ERR_CAST(foundinode);
124 }
125out:
126 d_add(dentry, foundinode);
127
128 return NULL;
129}