Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/isofs/namei.c |
| 3 | * |
| 4 | * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. |
| 5 | * |
| 6 | * (C) 1991 Linus Torvalds - minix filesystem |
| 7 | */ |
| 8 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/config.h> /* Joliet? */ |
| 10 | #include <linux/smp_lock.h> |
Al Viro | 94f2f71 | 2005-04-25 18:32:12 -0700 | [diff] [blame] | 11 | #include "isofs.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
| 13 | /* |
| 14 | * ok, we cannot use strncmp, as the name is not in our data space. |
| 15 | * Thus we'll have to use isofs_match. No big problem. Match also makes |
| 16 | * some sanity tests. |
| 17 | */ |
| 18 | static int |
| 19 | isofs_cmp(struct dentry * dentry, const char * compare, int dlen) |
| 20 | { |
| 21 | struct qstr qstr; |
| 22 | |
| 23 | if (!compare) |
| 24 | return 1; |
| 25 | |
| 26 | /* check special "." and ".." files */ |
| 27 | if (dlen == 1) { |
| 28 | /* "." */ |
| 29 | if (compare[0] == 0) { |
| 30 | if (!dentry->d_name.len) |
| 31 | return 0; |
| 32 | compare = "."; |
| 33 | } else if (compare[0] == 1) { |
| 34 | compare = ".."; |
| 35 | dlen = 2; |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | qstr.name = compare; |
| 40 | qstr.len = dlen; |
| 41 | return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr); |
| 42 | } |
| 43 | |
| 44 | /* |
| 45 | * isofs_find_entry() |
| 46 | * |
| 47 | * finds an entry in the specified directory with the wanted name. It |
| 48 | * returns the inode number of the found entry, or 0 on error. |
| 49 | */ |
| 50 | static unsigned long |
| 51 | isofs_find_entry(struct inode *dir, struct dentry *dentry, |
| 52 | unsigned long *block_rv, unsigned long* offset_rv, |
| 53 | char * tmpname, struct iso_directory_record * tmpde) |
| 54 | { |
| 55 | unsigned long bufsize = ISOFS_BUFFER_SIZE(dir); |
| 56 | unsigned char bufbits = ISOFS_BUFFER_BITS(dir); |
| 57 | unsigned long block, f_pos, offset, block_saved, offset_saved; |
| 58 | struct buffer_head * bh = NULL; |
| 59 | struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb); |
| 60 | |
| 61 | if (!ISOFS_I(dir)->i_first_extent) |
| 62 | return 0; |
| 63 | |
| 64 | f_pos = 0; |
| 65 | offset = 0; |
| 66 | block = 0; |
| 67 | |
| 68 | while (f_pos < dir->i_size) { |
| 69 | struct iso_directory_record * de; |
| 70 | int de_len, match, i, dlen; |
| 71 | char *dpnt; |
| 72 | |
| 73 | if (!bh) { |
| 74 | bh = isofs_bread(dir, block); |
| 75 | if (!bh) |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | de = (struct iso_directory_record *) (bh->b_data + offset); |
| 80 | |
| 81 | de_len = *(unsigned char *) de; |
| 82 | if (!de_len) { |
| 83 | brelse(bh); |
| 84 | bh = NULL; |
| 85 | f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); |
| 86 | block = f_pos >> bufbits; |
| 87 | offset = 0; |
| 88 | continue; |
| 89 | } |
| 90 | |
| 91 | block_saved = bh->b_blocknr; |
| 92 | offset_saved = offset; |
| 93 | offset += de_len; |
| 94 | f_pos += de_len; |
| 95 | |
| 96 | /* Make sure we have a full directory entry */ |
| 97 | if (offset >= bufsize) { |
| 98 | int slop = bufsize - offset + de_len; |
| 99 | memcpy(tmpde, de, slop); |
| 100 | offset &= bufsize - 1; |
| 101 | block++; |
| 102 | brelse(bh); |
| 103 | bh = NULL; |
| 104 | if (offset) { |
| 105 | bh = isofs_bread(dir, block); |
| 106 | if (!bh) |
| 107 | return 0; |
| 108 | memcpy((void *) tmpde + slop, bh->b_data, offset); |
| 109 | } |
| 110 | de = tmpde; |
| 111 | } |
| 112 | |
| 113 | dlen = de->name_len[0]; |
| 114 | dpnt = de->name; |
| 115 | |
| 116 | if (sbi->s_rock && |
| 117 | ((i = get_rock_ridge_filename(de, tmpname, dir)))) { |
| 118 | dlen = i; /* possibly -1 */ |
| 119 | dpnt = tmpname; |
| 120 | #ifdef CONFIG_JOLIET |
| 121 | } else if (sbi->s_joliet_level) { |
| 122 | dlen = get_joliet_filename(de, tmpname, dir); |
| 123 | dpnt = tmpname; |
| 124 | #endif |
| 125 | } else if (sbi->s_mapping == 'a') { |
| 126 | dlen = get_acorn_filename(de, tmpname, dir); |
| 127 | dpnt = tmpname; |
| 128 | } else if (sbi->s_mapping == 'n') { |
| 129 | dlen = isofs_name_translate(de, tmpname, dir); |
| 130 | dpnt = tmpname; |
| 131 | } |
| 132 | |
| 133 | /* |
Jeremy White | 9769f4e | 2005-06-21 17:16:53 -0700 | [diff] [blame] | 134 | * Skip hidden or associated files unless hide or showassoc, |
| 135 | * respectively, is set |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | */ |
| 137 | match = 0; |
| 138 | if (dlen > 0 && |
Jeremy White | 9769f4e | 2005-06-21 17:16:53 -0700 | [diff] [blame] | 139 | (sbi->s_hide =='n' || |
| 140 | (!(de->flags[-sbi->s_high_sierra] & 1))) && |
| 141 | (sbi->s_showassoc =='y' || |
| 142 | (!(de->flags[-sbi->s_high_sierra] & 4)))) { |
| 143 | match = (isofs_cmp(dentry, dpnt, dlen) == 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | } |
| 145 | if (match) { |
| 146 | isofs_normalize_block_and_offset(de, |
| 147 | &block_saved, |
| 148 | &offset_saved); |
| 149 | *block_rv = block_saved; |
| 150 | *offset_rv = offset_saved; |
Jeremy White | 9769f4e | 2005-06-21 17:16:53 -0700 | [diff] [blame] | 151 | brelse(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | return 1; |
| 153 | } |
| 154 | } |
Jeremy White | 9769f4e | 2005-06-21 17:16:53 -0700 | [diff] [blame] | 155 | brelse(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | return 0; |
| 157 | } |
| 158 | |
| 159 | struct dentry *isofs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) |
| 160 | { |
| 161 | int found; |
| 162 | unsigned long block, offset; |
| 163 | struct inode *inode; |
| 164 | struct page *page; |
| 165 | |
| 166 | dentry->d_op = dir->i_sb->s_root->d_op; |
| 167 | |
| 168 | page = alloc_page(GFP_USER); |
| 169 | if (!page) |
| 170 | return ERR_PTR(-ENOMEM); |
| 171 | |
| 172 | lock_kernel(); |
| 173 | found = isofs_find_entry(dir, dentry, |
| 174 | &block, &offset, |
| 175 | page_address(page), |
| 176 | 1024 + page_address(page)); |
| 177 | __free_page(page); |
| 178 | |
| 179 | inode = NULL; |
| 180 | if (found) { |
| 181 | inode = isofs_iget(dir->i_sb, block, offset); |
| 182 | if (!inode) { |
| 183 | unlock_kernel(); |
| 184 | return ERR_PTR(-EACCES); |
| 185 | } |
| 186 | } |
| 187 | unlock_kernel(); |
Pekka Enberg | 2ff6b1c | 2006-01-14 13:21:09 -0800 | [diff] [blame] | 188 | return d_splice_alias(inode, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | } |