Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * dir.c |
| 3 | * |
| 4 | * PURPOSE |
| 5 | * Directory handling routines for the OSTA-UDF(tm) filesystem. |
| 6 | * |
| 7 | * CONTACTS |
| 8 | * E-mail regarding any portion of the Linux UDF file system should be |
| 9 | * directed to the development team mailing list (run by majordomo): |
| 10 | * linux_udf@hpesjro.fc.hp.com |
| 11 | * |
| 12 | * COPYRIGHT |
| 13 | * This file is distributed under the terms of the GNU General Public |
| 14 | * License (GPL). Copies of the GPL can be obtained from: |
| 15 | * ftp://prep.ai.mit.edu/pub/gnu/GPL |
| 16 | * Each contributing author retains all rights to their own work. |
| 17 | * |
| 18 | * (C) 1998-2004 Ben Fennema |
| 19 | * |
| 20 | * HISTORY |
| 21 | * |
| 22 | * 10/05/98 dgb Split directory operations into its own file |
| 23 | * Implemented directory reads via do_udf_readdir |
| 24 | * 10/06/98 Made directory operations work! |
| 25 | * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG |
| 26 | * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading |
| 27 | * across blocks. |
| 28 | * 12/12/98 Split out the lookup code to namei.c. bulk of directory |
| 29 | * code now in directory.c:udf_fileident_read. |
| 30 | */ |
| 31 | |
| 32 | #include "udfdecl.h" |
| 33 | |
| 34 | #include <linux/string.h> |
| 35 | #include <linux/errno.h> |
| 36 | #include <linux/mm.h> |
| 37 | #include <linux/slab.h> |
| 38 | #include <linux/smp_lock.h> |
| 39 | #include <linux/buffer_head.h> |
| 40 | |
| 41 | #include "udf_i.h" |
| 42 | #include "udf_sb.h" |
| 43 | |
| 44 | /* Prototypes for file operations */ |
| 45 | static int udf_readdir(struct file *, void *, filldir_t); |
| 46 | static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *); |
| 47 | |
| 48 | /* readdir and lookup functions */ |
| 49 | |
| 50 | struct file_operations udf_dir_operations = { |
| 51 | .read = generic_read_dir, |
| 52 | .readdir = udf_readdir, |
| 53 | .ioctl = udf_ioctl, |
| 54 | .fsync = udf_fsync_file, |
| 55 | }; |
| 56 | |
| 57 | /* |
| 58 | * udf_readdir |
| 59 | * |
| 60 | * PURPOSE |
| 61 | * Read a directory entry. |
| 62 | * |
| 63 | * DESCRIPTION |
| 64 | * Optional - sys_getdents() will return -ENOTDIR if this routine is not |
| 65 | * available. |
| 66 | * |
| 67 | * Refer to sys_getdents() in fs/readdir.c |
| 68 | * sys_getdents() -> . |
| 69 | * |
| 70 | * PRE-CONDITIONS |
| 71 | * filp Pointer to directory file. |
| 72 | * buf Pointer to directory entry buffer. |
| 73 | * filldir Pointer to filldir function. |
| 74 | * |
| 75 | * POST-CONDITIONS |
| 76 | * <return> >=0 on success. |
| 77 | * |
| 78 | * HISTORY |
| 79 | * July 1, 1997 - Andrew E. Mileski |
| 80 | * Written, tested, and released. |
| 81 | */ |
| 82 | |
| 83 | int udf_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| 84 | { |
| 85 | struct inode *dir = filp->f_dentry->d_inode; |
| 86 | int result; |
| 87 | |
| 88 | lock_kernel(); |
| 89 | |
| 90 | if ( filp->f_pos == 0 ) |
| 91 | { |
| 92 | if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) |
| 93 | { |
| 94 | unlock_kernel(); |
| 95 | return 0; |
| 96 | } |
| 97 | filp->f_pos ++; |
| 98 | } |
| 99 | |
| 100 | result = do_udf_readdir(dir, filp, filldir, dirent); |
| 101 | unlock_kernel(); |
| 102 | return result; |
| 103 | } |
| 104 | |
| 105 | static int |
| 106 | do_udf_readdir(struct inode * dir, struct file *filp, filldir_t filldir, void *dirent) |
| 107 | { |
| 108 | struct udf_fileident_bh fibh; |
| 109 | struct fileIdentDesc *fi=NULL; |
| 110 | struct fileIdentDesc cfi; |
| 111 | int block, iblock; |
| 112 | loff_t nf_pos = filp->f_pos - 1; |
| 113 | int flen; |
| 114 | char fname[UDF_NAME_LEN]; |
| 115 | char *nameptr; |
| 116 | uint16_t liu; |
| 117 | uint8_t lfi; |
| 118 | loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2; |
| 119 | struct buffer_head * bh = NULL, * tmp, * bha[16]; |
| 120 | kernel_lb_addr bloc, eloc; |
| 121 | uint32_t extoffset, elen, offset; |
| 122 | int i, num; |
| 123 | unsigned int dt_type; |
| 124 | |
| 125 | if (nf_pos >= size) |
| 126 | return 0; |
| 127 | |
| 128 | if (nf_pos == 0) |
| 129 | nf_pos = (udf_ext0_offset(dir) >> 2); |
| 130 | |
| 131 | fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2; |
| 132 | if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) |
| 133 | fibh.sbh = fibh.ebh = NULL; |
| 134 | else if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2), |
| 135 | &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30)) |
| 136 | { |
| 137 | offset >>= dir->i_sb->s_blocksize_bits; |
| 138 | block = udf_get_lb_pblock(dir->i_sb, eloc, offset); |
| 139 | if ((++offset << dir->i_sb->s_blocksize_bits) < elen) |
| 140 | { |
| 141 | if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT) |
| 142 | extoffset -= sizeof(short_ad); |
| 143 | else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG) |
| 144 | extoffset -= sizeof(long_ad); |
| 145 | } |
| 146 | else |
| 147 | offset = 0; |
| 148 | |
| 149 | if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) |
| 150 | { |
| 151 | udf_release_data(bh); |
| 152 | return -EIO; |
| 153 | } |
| 154 | |
| 155 | if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9))-1))) |
| 156 | { |
| 157 | i = 16 >> (dir->i_sb->s_blocksize_bits - 9); |
| 158 | if (i+offset > (elen >> dir->i_sb->s_blocksize_bits)) |
| 159 | i = (elen >> dir->i_sb->s_blocksize_bits)-offset; |
| 160 | for (num=0; i>0; i--) |
| 161 | { |
| 162 | block = udf_get_lb_pblock(dir->i_sb, eloc, offset+i); |
| 163 | tmp = udf_tgetblk(dir->i_sb, block); |
| 164 | if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) |
| 165 | bha[num++] = tmp; |
| 166 | else |
| 167 | brelse(tmp); |
| 168 | } |
| 169 | if (num) |
| 170 | { |
| 171 | ll_rw_block(READA, num, bha); |
| 172 | for (i=0; i<num; i++) |
| 173 | brelse(bha[i]); |
| 174 | } |
| 175 | } |
| 176 | } |
| 177 | else |
| 178 | { |
| 179 | udf_release_data(bh); |
| 180 | return -ENOENT; |
| 181 | } |
| 182 | |
| 183 | while ( nf_pos < size ) |
| 184 | { |
| 185 | filp->f_pos = nf_pos + 1; |
| 186 | |
| 187 | fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh); |
| 188 | |
| 189 | if (!fi) |
| 190 | { |
| 191 | if (fibh.sbh != fibh.ebh) |
| 192 | udf_release_data(fibh.ebh); |
| 193 | udf_release_data(fibh.sbh); |
| 194 | udf_release_data(bh); |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | liu = le16_to_cpu(cfi.lengthOfImpUse); |
| 199 | lfi = cfi.lengthFileIdent; |
| 200 | |
| 201 | if (fibh.sbh == fibh.ebh) |
| 202 | nameptr = fi->fileIdent + liu; |
| 203 | else |
| 204 | { |
| 205 | int poffset; /* Unpaded ending offset */ |
| 206 | |
| 207 | poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; |
| 208 | |
| 209 | if (poffset >= lfi) |
| 210 | nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); |
| 211 | else |
| 212 | { |
| 213 | nameptr = fname; |
| 214 | memcpy(nameptr, fi->fileIdent + liu, lfi - poffset); |
| 215 | memcpy(nameptr + lfi - poffset, fibh.ebh->b_data, poffset); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | if ( (cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0 ) |
| 220 | { |
| 221 | if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE) ) |
| 222 | continue; |
| 223 | } |
| 224 | |
| 225 | if ( (cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0 ) |
| 226 | { |
| 227 | if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE) ) |
| 228 | continue; |
| 229 | } |
| 230 | |
| 231 | if ( cfi.fileCharacteristics & FID_FILE_CHAR_PARENT ) |
| 232 | { |
| 233 | iblock = parent_ino(filp->f_dentry); |
| 234 | flen = 2; |
| 235 | memcpy(fname, "..", flen); |
| 236 | dt_type = DT_DIR; |
| 237 | } |
| 238 | else |
| 239 | { |
| 240 | kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation); |
| 241 | |
| 242 | iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0); |
| 243 | flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi); |
| 244 | dt_type = DT_UNKNOWN; |
| 245 | } |
| 246 | |
| 247 | if (flen) |
| 248 | { |
| 249 | if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) |
| 250 | { |
| 251 | if (fibh.sbh != fibh.ebh) |
| 252 | udf_release_data(fibh.ebh); |
| 253 | udf_release_data(fibh.sbh); |
| 254 | udf_release_data(bh); |
| 255 | return 0; |
| 256 | } |
| 257 | } |
| 258 | } /* end while */ |
| 259 | |
| 260 | filp->f_pos = nf_pos + 1; |
| 261 | |
| 262 | if (fibh.sbh != fibh.ebh) |
| 263 | udf_release_data(fibh.ebh); |
| 264 | udf_release_data(fibh.sbh); |
| 265 | udf_release_data(bh); |
| 266 | |
| 267 | return 0; |
| 268 | } |