diff options
Diffstat (limited to 'fs/affs/dir.c')
| -rw-r--r-- | fs/affs/dir.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/fs/affs/dir.c b/fs/affs/dir.c new file mode 100644 index 0000000..548efd0 --- /dev/null +++ b/fs/affs/dir.c @@ -0,0 +1,155 @@ +/* + * 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 + * + */ + +#include "affs.h" + +static int affs_readdir(struct file *, void *, filldir_t); + +struct file_operations affs_dir_operations = { + .read = generic_read_dir, + .readdir = affs_readdir, + .fsync = file_fsync, +}; + +/* + * directories can handle most operations... + */ +struct inode_operations affs_dir_inode_operations = { + .create = affs_create, + .lookup = affs_lookup, + .link = affs_link, + .unlink = affs_unlink, + .symlink = affs_symlink, + .mkdir = affs_mkdir, + .rmdir = affs_rmdir, + .rename = affs_rename, + .setattr = affs_notify_change, +}; + +static int +affs_readdir(struct file *filp, void *dirent, filldir_t filldir) +{ + struct inode *inode = filp->f_dentry->d_inode; + struct super_block *sb = inode->i_sb; + struct buffer_head *dir_bh; + struct buffer_head *fh_bh; + unsigned char *name; + int namelen; + u32 i; + int hash_pos; + int chain_pos; + u32 f_pos; + u32 ino; + int stored; + int res; + + pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos); + + stored = 0; + res = -EIO; + dir_bh = NULL; + fh_bh = NULL; + f_pos = filp->f_pos; + + if (f_pos == 0) { + filp->private_data = (void *)0; + if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0) + return 0; + filp->f_pos = f_pos = 1; + stored++; + } + if (f_pos == 1) { + if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_dentry), DT_DIR) < 0) + return stored; + filp->f_pos = f_pos = 2; + stored++; + } + + affs_lock_dir(inode); + chain_pos = (f_pos - 2) & 0xffff; + hash_pos = (f_pos - 2) >> 16; + if (chain_pos == 0xffff) { + affs_warning(sb, "readdir", "More than 65535 entries in chain"); + chain_pos = 0; + hash_pos++; + filp->f_pos = ((hash_pos << 16) | chain_pos) + 2; + } + dir_bh = affs_bread(sb, inode->i_ino); + if (!dir_bh) + goto readdir_out; + + /* If the directory hasn't changed since the last call to readdir(), + * we can jump directly to where we left off. + */ + ino = (u32)(long)filp->private_data; + if (ino && filp->f_version == inode->i_version) { + pr_debug("AFFS: readdir() left off=%d\n", ino); + goto inside; + } + + ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); + for (i = 0; ino && i < chain_pos; i++) { + fh_bh = affs_bread(sb, ino); + if (!fh_bh) { + affs_error(sb, "readdir","Cannot read block %d", i); + goto readdir_out; + } + ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); + affs_brelse(fh_bh); + fh_bh = NULL; + } + if (ino) + goto inside; + hash_pos++; + + for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) { + ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); + if (!ino) + continue; + f_pos = (hash_pos << 16) + 2; +inside: + do { + fh_bh = affs_bread(sb, ino); + if (!fh_bh) { + affs_error(sb, "readdir","Cannot read block %d", ino); + goto readdir_done; + } + + namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30); + name = AFFS_TAIL(sb, fh_bh)->name + 1; + pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n", + namelen, name, ino, hash_pos, f_pos); + if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0) + goto readdir_done; + stored++; + f_pos++; + ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); + affs_brelse(fh_bh); + fh_bh = NULL; + } while (ino); + } +readdir_done: + filp->f_pos = f_pos; + filp->f_version = inode->i_version; + filp->private_data = (void *)(long)ino; + res = stored; + +readdir_out: + affs_brelse(dir_bh); + affs_brelse(fh_bh); + affs_unlock_dir(inode); + pr_debug("AFFS: readdir()=%d\n", stored); + return res; +} |
