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 34 #include "udf_i.h" 35 #include "udf_sb.h" 36 37 38 static int udf_readdir(struct file *file, struct dir_context *ctx) 39 { 40 struct inode *dir = file_inode(file); 41 struct udf_inode_info *iinfo = UDF_I(dir); 42 struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL}; 43 struct fileIdentDesc *fi = NULL; 44 struct fileIdentDesc cfi; 45 int block, iblock; 46 loff_t nf_pos; 47 int flen; 48 unsigned char *fname = NULL; 49 unsigned char *nameptr; 50 uint16_t liu; 51 uint8_t lfi; 52 loff_t size = udf_ext0_offset(dir) + dir->i_size; 53 struct buffer_head *tmp, *bha[16]; 54 struct kernel_lb_addr eloc; 55 uint32_t elen; 56 sector_t offset; 57 int i, num, ret = 0; 58 struct extent_position epos = { NULL, 0, {0, 0} }; 59 struct super_block *sb = dir->i_sb; 60 61 if (ctx->pos == 0) { 62 if (!dir_emit_dot(file, ctx)) 63 return 0; 64 ctx->pos = 1; 65 } 66 nf_pos = (ctx->pos - 1) << 2; 67 if (nf_pos >= size) 68 goto out; 69 70 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS); 71 if (!fname) { 72 ret = -ENOMEM; 73 goto out; 74 } 75 76 if (nf_pos == 0) 77 nf_pos = udf_ext0_offset(dir); 78 79 fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1); 80 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { 81 if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits, 82 &epos, &eloc, &elen, &offset) 83 != (EXT_RECORDED_ALLOCATED >> 30)) { 84 ret = -ENOENT; 85 goto out; 86 } 87 block = udf_get_lb_pblock(sb, &eloc, offset); 88 if ((++offset << sb->s_blocksize_bits) < elen) { 89 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 90 epos.offset -= sizeof(struct short_ad); 91 else if (iinfo->i_alloc_type == 92 ICBTAG_FLAG_AD_LONG) 93 epos.offset -= sizeof(struct long_ad); 94 } else { 95 offset = 0; 96 } 97 98 if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) { 99 ret = -EIO; 100 goto out; 101 } 102 103 if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) { 104 i = 16 >> (sb->s_blocksize_bits - 9); 105 if (i + offset > (elen >> sb->s_blocksize_bits)) 106 i = (elen >> sb->s_blocksize_bits) - offset; 107 for (num = 0; i > 0; i--) { 108 block = udf_get_lb_pblock(sb, &eloc, offset + i); 109 tmp = udf_tgetblk(sb, block); 110 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 111 bha[num++] = tmp; 112 else 113 brelse(tmp); 114 } 115 if (num) { 116 ll_rw_block(READA, num, bha); 117 for (i = 0; i < num; i++) 118 brelse(bha[i]); 119 } 120 } 121 } 122 123 while (nf_pos < size) { 124 struct kernel_lb_addr tloc; 125 126 ctx->pos = (nf_pos >> 2) + 1; 127 128 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 129 &elen, &offset); 130 if (!fi) 131 goto out; 132 133 liu = le16_to_cpu(cfi.lengthOfImpUse); 134 lfi = cfi.lengthFileIdent; 135 136 if (fibh.sbh == fibh.ebh) { 137 nameptr = fi->fileIdent + liu; 138 } else { 139 int poffset; /* Unpaded ending offset */ 140 141 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 142 143 if (poffset >= lfi) { 144 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 145 } else { 146 nameptr = fname; 147 memcpy(nameptr, fi->fileIdent + liu, 148 lfi - poffset); 149 memcpy(nameptr + lfi - poffset, 150 fibh.ebh->b_data, poffset); 151 } 152 } 153 154 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 155 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE)) 156 continue; 157 } 158 159 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 160 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE)) 161 continue; 162 } 163 164 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 165 if (!dir_emit_dotdot(file, ctx)) 166 goto out; 167 continue; 168 } 169 170 flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN); 171 if (!flen) 172 continue; 173 174 tloc = lelb_to_cpu(cfi.icb.extLocation); 175 iblock = udf_get_lb_pblock(sb, &tloc, 0); 176 if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN)) 177 goto out; 178 } /* end while */ 179 180 ctx->pos = (nf_pos >> 2) + 1; 181 182 out: 183 if (fibh.sbh != fibh.ebh) 184 brelse(fibh.ebh); 185 brelse(fibh.sbh); 186 brelse(epos.bh); 187 kfree(fname); 188 189 return ret; 190 } 191 192 /* readdir and lookup functions */ 193 const struct file_operations udf_dir_operations = { 194 .llseek = generic_file_llseek, 195 .read = generic_read_dir, 196 .iterate = udf_readdir, 197 .unlocked_ioctl = udf_ioctl, 198 .fsync = generic_file_fsync, 199 }; 200