1 /* 2 * dir.c 3 * 4 * PURPOSE 5 * Directory handling routines for the OSTA-UDF(tm) filesystem. 6 * 7 * COPYRIGHT 8 * This file is distributed under the terms of the GNU General Public 9 * License (GPL). Copies of the GPL can be obtained from: 10 * ftp://prep.ai.mit.edu/pub/gnu/GPL 11 * Each contributing author retains all rights to their own work. 12 * 13 * (C) 1998-2004 Ben Fennema 14 * 15 * HISTORY 16 * 17 * 10/05/98 dgb Split directory operations into its own file 18 * Implemented directory reads via do_udf_readdir 19 * 10/06/98 Made directory operations work! 20 * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG 21 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading 22 * across blocks. 23 * 12/12/98 Split out the lookup code to namei.c. bulk of directory 24 * code now in directory.c:udf_fileident_read. 25 */ 26 27 #include "udfdecl.h" 28 29 #include <linux/string.h> 30 #include <linux/errno.h> 31 #include <linux/mm.h> 32 #include <linux/slab.h> 33 #include <linux/buffer_head.h> 34 35 #include "udf_i.h" 36 #include "udf_sb.h" 37 38 static int do_udf_readdir(struct inode *dir, struct file *filp, 39 filldir_t filldir, void *dirent) 40 { 41 struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL}; 42 struct fileIdentDesc *fi = NULL; 43 struct fileIdentDesc cfi; 44 int block, iblock; 45 loff_t nf_pos = (filp->f_pos - 1) << 2; 46 int flen; 47 unsigned char *fname = NULL; 48 unsigned char *nameptr; 49 uint16_t liu; 50 uint8_t lfi; 51 loff_t size = udf_ext0_offset(dir) + dir->i_size; 52 struct buffer_head *tmp, *bha[16]; 53 struct kernel_lb_addr eloc; 54 uint32_t elen; 55 sector_t offset; 56 int i, num, ret = 0; 57 unsigned int dt_type; 58 struct extent_position epos = { NULL, 0, {0, 0} }; 59 struct udf_inode_info *iinfo; 60 61 if (nf_pos >= size) 62 goto out; 63 64 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS); 65 if (!fname) { 66 ret = -ENOMEM; 67 goto out; 68 } 69 70 if (nf_pos == 0) 71 nf_pos = udf_ext0_offset(dir); 72 73 fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1); 74 iinfo = UDF_I(dir); 75 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { 76 if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits, 77 &epos, &eloc, &elen, &offset) 78 != (EXT_RECORDED_ALLOCATED >> 30)) { 79 ret = -ENOENT; 80 goto out; 81 } 82 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset); 83 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) { 84 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 85 epos.offset -= sizeof(struct short_ad); 86 else if (iinfo->i_alloc_type == 87 ICBTAG_FLAG_AD_LONG) 88 epos.offset -= sizeof(struct long_ad); 89 } else { 90 offset = 0; 91 } 92 93 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) { 94 ret = -EIO; 95 goto out; 96 } 97 98 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) { 99 i = 16 >> (dir->i_sb->s_blocksize_bits - 9); 100 if (i + offset > (elen >> dir->i_sb->s_blocksize_bits)) 101 i = (elen >> dir->i_sb->s_blocksize_bits) - offset; 102 for (num = 0; i > 0; i--) { 103 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset + i); 104 tmp = udf_tgetblk(dir->i_sb, block); 105 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 106 bha[num++] = tmp; 107 else 108 brelse(tmp); 109 } 110 if (num) { 111 ll_rw_block(READA, num, bha); 112 for (i = 0; i < num; i++) 113 brelse(bha[i]); 114 } 115 } 116 } 117 118 while (nf_pos < size) { 119 filp->f_pos = (nf_pos >> 2) + 1; 120 121 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 122 &elen, &offset); 123 if (!fi) 124 goto out; 125 126 liu = le16_to_cpu(cfi.lengthOfImpUse); 127 lfi = cfi.lengthFileIdent; 128 129 if (fibh.sbh == fibh.ebh) { 130 nameptr = fi->fileIdent + liu; 131 } else { 132 int poffset; /* Unpaded ending offset */ 133 134 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 135 136 if (poffset >= lfi) { 137 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 138 } else { 139 nameptr = fname; 140 memcpy(nameptr, fi->fileIdent + liu, 141 lfi - poffset); 142 memcpy(nameptr + lfi - poffset, 143 fibh.ebh->b_data, poffset); 144 } 145 } 146 147 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 148 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE)) 149 continue; 150 } 151 152 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 153 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE)) 154 continue; 155 } 156 157 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 158 iblock = parent_ino(filp->f_path.dentry); 159 flen = 2; 160 memcpy(fname, "..", flen); 161 dt_type = DT_DIR; 162 } else { 163 struct kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation); 164 165 iblock = udf_get_lb_pblock(dir->i_sb, &tloc, 0); 166 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi); 167 dt_type = DT_UNKNOWN; 168 } 169 170 if (flen && filldir(dirent, fname, flen, filp->f_pos, 171 iblock, dt_type) < 0) 172 goto out; 173 } /* end while */ 174 175 filp->f_pos = (nf_pos >> 2) + 1; 176 177 out: 178 if (fibh.sbh != fibh.ebh) 179 brelse(fibh.ebh); 180 brelse(fibh.sbh); 181 brelse(epos.bh); 182 kfree(fname); 183 184 return ret; 185 } 186 187 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir) 188 { 189 struct inode *dir = filp->f_path.dentry->d_inode; 190 int result; 191 192 if (filp->f_pos == 0) { 193 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) { 194 return 0; 195 } 196 filp->f_pos++; 197 } 198 199 result = do_udf_readdir(dir, filp, filldir, dirent); 200 return result; 201 } 202 203 /* readdir and lookup functions */ 204 const struct file_operations udf_dir_operations = { 205 .llseek = generic_file_llseek, 206 .read = generic_read_dir, 207 .readdir = udf_readdir, 208 .unlocked_ioctl = udf_ioctl, 209 .fsync = generic_file_fsync, 210 }; 211