| 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 = file_inode(filp); |
| 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 | }; |