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 39 static int udf_readdir(struct file *file, struct dir_context *ctx) 40 { 41 struct inode *dir = file_inode(file); 42 struct udf_inode_info *iinfo = UDF_I(dir); 43 struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL}; 44 struct fileIdentDesc *fi = NULL; 45 struct fileIdentDesc cfi; 46 int block, iblock; 47 loff_t nf_pos; 48 int flen; 49 unsigned char *fname = NULL; 50 unsigned char *nameptr; 51 uint16_t liu; 52 uint8_t lfi; 53 loff_t size = udf_ext0_offset(dir) + dir->i_size; 54 struct buffer_head *tmp, *bha[16]; 55 struct kernel_lb_addr eloc; 56 uint32_t elen; 57 sector_t offset; 58 int i, num, ret = 0; 59 struct extent_position epos = { NULL, 0, {0, 0} }; 60 struct super_block *sb = dir->i_sb; 61 62 if (ctx->pos == 0) { 63 if (!dir_emit_dot(file, ctx)) 64 return 0; 65 ctx->pos = 1; 66 } 67 nf_pos = (ctx->pos - 1) << 2; 68 if (nf_pos >= size) 69 goto out; 70 71 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS); 72 if (!fname) { 73 ret = -ENOMEM; 74 goto out; 75 } 76 77 if (nf_pos == 0) 78 nf_pos = udf_ext0_offset(dir); 79 80 fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1); 81 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { 82 if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits, 83 &epos, &eloc, &elen, &offset) 84 != (EXT_RECORDED_ALLOCATED >> 30)) { 85 ret = -ENOENT; 86 goto out; 87 } 88 block = udf_get_lb_pblock(sb, &eloc, offset); 89 if ((++offset << sb->s_blocksize_bits) < elen) { 90 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 91 epos.offset -= sizeof(struct short_ad); 92 else if (iinfo->i_alloc_type == 93 ICBTAG_FLAG_AD_LONG) 94 epos.offset -= sizeof(struct long_ad); 95 } else { 96 offset = 0; 97 } 98 99 if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) { 100 ret = -EIO; 101 goto out; 102 } 103 104 if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) { 105 i = 16 >> (sb->s_blocksize_bits - 9); 106 if (i + offset > (elen >> sb->s_blocksize_bits)) 107 i = (elen >> sb->s_blocksize_bits) - offset; 108 for (num = 0; i > 0; i--) { 109 block = udf_get_lb_pblock(sb, &eloc, offset + i); 110 tmp = udf_tgetblk(sb, block); 111 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 112 bha[num++] = tmp; 113 else 114 brelse(tmp); 115 } 116 if (num) { 117 ll_rw_block(READA, num, bha); 118 for (i = 0; i < num; i++) 119 brelse(bha[i]); 120 } 121 } 122 } 123 124 while (nf_pos < size) { 125 struct kernel_lb_addr tloc; 126 127 ctx->pos = (nf_pos >> 2) + 1; 128 129 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 130 &elen, &offset); 131 if (!fi) 132 goto out; 133 134 liu = le16_to_cpu(cfi.lengthOfImpUse); 135 lfi = cfi.lengthFileIdent; 136 137 if (fibh.sbh == fibh.ebh) { 138 nameptr = fi->fileIdent + liu; 139 } else { 140 int poffset; /* Unpaded ending offset */ 141 142 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 143 144 if (poffset >= lfi) { 145 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 146 } else { 147 nameptr = fname; 148 memcpy(nameptr, fi->fileIdent + liu, 149 lfi - poffset); 150 memcpy(nameptr + lfi - poffset, 151 fibh.ebh->b_data, poffset); 152 } 153 } 154 155 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 156 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE)) 157 continue; 158 } 159 160 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 161 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE)) 162 continue; 163 } 164 165 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 166 if (!dir_emit_dotdot(file, ctx)) 167 goto out; 168 continue; 169 } 170 171 flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN); 172 if (!flen) 173 continue; 174 175 tloc = lelb_to_cpu(cfi.icb.extLocation); 176 iblock = udf_get_lb_pblock(sb, &tloc, 0); 177 if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN)) 178 goto out; 179 } /* end while */ 180 181 ctx->pos = (nf_pos >> 2) + 1; 182 183 out: 184 if (fibh.sbh != fibh.ebh) 185 brelse(fibh.ebh); 186 brelse(fibh.sbh); 187 brelse(epos.bh); 188 kfree(fname); 189 190 return ret; 191 } 192 193 /* readdir and lookup functions */ 194 const struct file_operations udf_dir_operations = { 195 .llseek = generic_file_llseek, 196 .read = generic_read_dir, 197 .iterate = udf_readdir, 198 .unlocked_ioctl = udf_ioctl, 199 .fsync = generic_file_fsync, 200 }; 201