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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 | /* * linux/fs/affs/dir.c * * (c) 1996 Hans-Joachim Widmaier - Rewritten * * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. * * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. * * (C) 1991 Linus Torvalds - minix filesystem * * affs directory handling functions * */ #define DEBUG 0 #include <asm/uaccess.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/affs_fs.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/amigaffs.h> static int affs_readdir(struct file *, void *, filldir_t); static ssize_t affs_dir_read(struct file *, char *, size_t, loff_t *); static struct file_operations affs_dir_operations = { NULL, /* lseek - default */ affs_dir_read, /* read */ NULL, /* write - bad */ affs_readdir, /* readdir */ NULL, /* poll - default */ NULL, /* ioctl - default */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* flush */ NULL, /* no special release code */ file_fsync /* default fsync */ }; /* * directories can handle most operations... */ struct inode_operations affs_dir_inode_operations = { &affs_dir_operations, /* default directory file-ops */ affs_create, /* create */ affs_lookup, /* lookup */ affs_link, /* link */ affs_unlink, /* unlink */ affs_symlink, /* symlink */ affs_mkdir, /* mkdir */ affs_rmdir, /* rmdir */ NULL, /* mknod */ affs_rename, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL, /* permissions */ NULL, /* smap */ NULL, /* updatepage */ NULL /* revalidate */ }; static ssize_t affs_dir_read(struct file *filp, char *buf, size_t count, loff_t *ppos) { return -EISDIR; } static int affs_readdir(struct file *filp, void *dirent, filldir_t filldir) { int j, namelen; s32 i; int hash_pos; int chain_pos; unsigned long ino; int stored; unsigned char *name; struct buffer_head *dir_bh; struct buffer_head *fh_bh; struct inode *dir; struct inode *inode = filp->f_dentry->d_inode; pr_debug("AFFS: readdir(ino=%lu,f_pos=%lu)\n",inode->i_ino,(unsigned long)filp->f_pos); if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF; stored = 0; dir_bh = NULL; fh_bh = NULL; dir = NULL; ino = inode->i_ino; if (filp->f_pos == 0) { filp->private_data = (void *)0; if (filldir(dirent,".",1,filp->f_pos,inode->i_ino) < 0) { return 0; } ++filp->f_pos; stored++; } if (filp->f_pos == 1) { if (filldir(dirent,"..",2,filp->f_pos,affs_parent_ino(inode)) < 0) { return stored; } filp->f_pos = 2; stored++; } chain_pos = (filp->f_pos - 2) & 0xffff; hash_pos = (filp->f_pos - 2) >> 16; if (chain_pos == 0xffff) { affs_warning(inode->i_sb,"readdir","More than 65535 entries in chain"); chain_pos = 0; hash_pos++; filp->f_pos = ((hash_pos << 16) | chain_pos) + 2; } if (!(dir_bh = affs_bread(inode->i_dev,inode->i_ino, AFFS_I2BSIZE(inode)))) goto readdir_done; while (1) { while (hash_pos < AFFS_I2HSIZE(inode) && !((struct dir_front *)dir_bh->b_data)->hashtable[hash_pos]) hash_pos++; if (hash_pos >= AFFS_I2HSIZE(inode)) break; i = be32_to_cpu(((struct dir_front *)dir_bh->b_data)->hashtable[hash_pos]); j = chain_pos; /* If the directory hasn't changed since the last call to readdir(), * we can jump directly to where we left off. */ if (filp->private_data && filp->f_version == inode->i_version) { i = (s32)filp->private_data; j = 0; pr_debug("AFFS: readdir() left off=%d\n",i); } filp->f_version = inode->i_version; pr_debug("AFFS: hash_pos=%d chain_pos=%d\n",hash_pos,chain_pos); while (i) { if (!(fh_bh = affs_bread(inode->i_dev,i,AFFS_I2BSIZE(inode)))) { affs_error(inode->i_sb,"readdir","Cannot read block %d",i); goto readdir_done; } ino = i; i = be32_to_cpu(FILE_END(fh_bh->b_data,inode)->hash_chain); if (j == 0) break; affs_brelse(fh_bh); fh_bh = NULL; j--; } if (fh_bh) { namelen = affs_get_file_name(AFFS_I2BSIZE(inode),fh_bh->b_data,&name); pr_debug("AFFS: readdir(): filldir(\"%.*s\",ino=%lu), i=%d\n", namelen,name,ino,i); filp->private_data = (void *)ino; if (filldir(dirent,name,namelen,filp->f_pos,ino) < 0) goto readdir_done; filp->private_data = (void *)i; affs_brelse(fh_bh); fh_bh = NULL; stored++; } if (i == 0) { hash_pos++; chain_pos = 0; } else chain_pos++; filp->f_pos = ((hash_pos << 16) | chain_pos) + 2; } readdir_done: affs_brelse(dir_bh); affs_brelse(fh_bh); pr_debug("AFFS: readdir()=%d\n",stored); return stored; } |