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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 | /* * linux/fs/ufs/ufs_dir.c * * Copyright (C) 1996 * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu) * Laboratory for Computer Science Research Computing Facility * Rutgers, The State University of New Jersey * * swab support by Francois-Rene Rideau <rideau@ens.fr> 19970406 * * 4.4BSD (FreeBSD) support added on February 1st 1998 by * Niels Kristian Bech Jensen <nkbj@image.dk> partially based * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>. */ #include <linux/fs.h> #include "ufs_swab.h" /* * This is blatantly stolen from ext2fs */ static int ufs_readdir (struct file * filp, void * dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; int error = 0; unsigned long offset, lblk, blk; int i, stored; struct buffer_head * bh; struct ufs_direct * de; struct super_block * sb; int de_reclen; __u32 flags; /* Isn't that already done in the upper layer??? * the VFS layer really needs some explicit documentation! */ if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF; sb = inode->i_sb; flags = sb->u.ufs_sb.s_flags; if (flags & UFS_DEBUG) { printk("ufs_readdir: ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos); ufs_print_inode(inode); } stored = 0; bh = NULL; offset = filp->f_pos & (sb->s_blocksize - 1); while (!error && !stored && filp->f_pos < inode->i_size) { lblk = (filp->f_pos) >> sb->s_blocksize_bits; /* XXX - ufs_bmap() call needs error checking */ blk = ufs_bmap(inode, lblk); bh = bread (sb->s_dev, blk, sb->s_blocksize); if (!bh) { /* XXX - error - skip to the next block */ printk("ufs_readdir: " "dir inode %lu has a hole at offset %lu\n", inode->i_ino, (unsigned long int)filp->f_pos); filp->f_pos += sb->s_blocksize - offset; continue; } revalidate: /* If the dir block has changed since the last call to * readdir(2), then we might be pointing to an invalid * dirent right now. Scan from the start of the block * to make sure. */ if (filp->f_version != inode->i_version) { for (i = 0; i < sb->s_blocksize && i < offset; ) { de = (struct ufs_direct *) (bh->b_data + i); /* It's too expensive to do a full * dirent test each time round this * loop, but we do have to test at * least that it is non-zero. A * failure will be detected in the * dirent test below. */ de_reclen = SWAB16(de->d_reclen); if (de_reclen < 1) break; i += de_reclen; } offset = i; filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) | offset; filp->f_version = inode->i_version; } while (!error && filp->f_pos < inode->i_size && offset < sb->s_blocksize) { de = (struct ufs_direct *) (bh->b_data + offset); /* XXX - put in a real ufs_check_dir_entry() */ if ((de->d_reclen == 0) || (NAMLEN(de) == 0)) { /* SWAB16() was unneeded -- compare to 0 */ filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1)) + sb->s_blocksize; brelse(bh); return stored; } #if 0 /* XXX */ if (!ext2_check_dir_entry ("ext2_readdir", inode, de, /* XXX - beware about de having to be swabped somehow */ bh, offset)) { /* On error, skip the f_pos to the next block. */ filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1)) + sb->s_blocksize; brelse (bh); return stored; } #endif /* XXX */ offset += SWAB16(de->d_reclen); if (de->d_ino) { /* SWAB16() was unneeded -- compare to 0 */ /* We might block in the next section * if the data destination is * currently swapped out. So, use a * version stamp to detect whether or * not the directory has been modified * during the copy operation. */ unsigned long version = inode->i_version; if (flags & UFS_DEBUG) { printk("ufs_readdir: filldir(%s,%u)\n", de->d_name, SWAB32(de->d_ino)); } error = filldir(dirent, de->d_name, NAMLEN(de), filp->f_pos, SWAB32(de->d_ino)); if (error) break; if (version != inode->i_version) goto revalidate; stored ++; } filp->f_pos += SWAB16(de->d_reclen); } offset = 0; brelse (bh); } #if 0 /* XXX */ if (!IS_RDONLY(inode)) { inode->i_atime = CURRENT_TIME; inode->i_dirt = 1; } #endif /* XXX */ return 0; } static struct file_operations ufs_dir_operations = { NULL, /* lseek */ NULL, /* read */ NULL, /* write */ ufs_readdir, /* readdir */ NULL, /* select */ NULL, /* ioctl */ NULL, /* mmap */ NULL, /* open */ NULL, /* release */ file_fsync, /* fsync */ NULL, /* fasync */ NULL, /* check_media_change */ NULL, /* revalidate */ }; struct inode_operations ufs_dir_inode_operations = { &ufs_dir_operations, /* default directory file operations */ NULL, /* create */ ufs_lookup, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL, /* permission */ NULL, /* smap */ }; |