/* * fs/bfs/dir.c * BFS directory operations. * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com> * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005 */ #include <linux/time.h> #include <linux/string.h> #include <linux/fs.h> #include <linux/smp_lock.h> #include <linux/buffer_head.h> #include <linux/sched.h> #include "bfs.h" #undef DEBUG #ifdef DEBUG #define dprintf(x...) printf(x) #else #define dprintf(x...) #endif static int bfs_add_entry(struct inode *dir, const unsigned char *name, int namelen, int ino); static struct buffer_head *bfs_find_entry(struct inode *dir, const unsigned char *name, int namelen, struct bfs_dirent **res_dir); static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir) { struct inode *dir = f->f_path.dentry->d_inode; struct buffer_head *bh; struct bfs_dirent *de; unsigned int offset; int block; lock_kernel(); if (f->f_pos & (BFS_DIRENT_SIZE - 1)) { printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos, dir->i_sb->s_id, dir->i_ino); unlock_kernel(); return -EBADF; } while (f->f_pos < dir->i_size) { offset = f->f_pos & (BFS_BSIZE - 1); block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS); bh = sb_bread(dir->i_sb, block); if (!bh) { f->f_pos += BFS_BSIZE - offset; continue; } do { de = (struct bfs_dirent *)(bh->b_data + offset); if (de->ino) { int size = strnlen(de->name, BFS_NAMELEN); if (filldir(dirent, de->name, size, f->f_pos, le16_to_cpu(de->ino), DT_UNKNOWN) < 0) { brelse(bh); unlock_kernel(); return 0; } } offset += BFS_DIRENT_SIZE; f->f_pos += BFS_DIRENT_SIZE; } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size)); brelse(bh); } unlock_kernel(); return 0; } const struct file_operations bfs_dir_operations = { .read = generic_read_dir, .readdir = bfs_readdir, .fsync = file_fsync, }; extern void dump_imap(const char *, struct super_block *); static int bfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { int err; struct inode *inode; struct super_block *s = dir->i_sb; struct bfs_sb_info *info = BFS_SB(s); unsigned long ino; inode = new_inode(s); if (!inode) return -ENOSPC; lock_kernel(); ino = find_first_zero_bit(info->si_imap, info->si_lasti); if (ino > info->si_lasti) { unlock_kernel(); iput(inode); return -ENOSPC; } set_bit(ino, info->si_imap); info->si_freei--; inode->i_uid = current->fsuid; inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; inode->i_blocks = 0; inode->i_op = &bfs_file_inops; inode->i_fop = &bfs_file_operations; inode->i_mapping->a_ops = &bfs_aops; inode->i_mode = mode; inode->i_ino = ino; BFS_I(inode)->i_dsk_ino = ino; BFS_I(inode)->i_sblock = 0; BFS_I(inode)->i_eblock = 0; insert_inode_hash(inode); mark_inode_dirty(inode); dump_imap("create", s); err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino); if (err) { inode_dec_link_count(inode); iput(inode); unlock_kernel(); return err; } unlock_kernel(); d_instantiate(dentry, inode); return 0; } static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct inode *inode = NULL; struct buffer_head *bh; struct bfs_dirent *de; if (dentry->d_name.len > BFS_NAMELEN) return ERR_PTR(-ENAMETOOLONG); lock_kernel(); bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); if (bh) { unsigned long ino = (unsigned long)le16_to_cpu(de->ino); brelse(bh); inode = iget(dir->i_sb, ino); if (!inode) { unlock_kernel(); return ERR_PTR(-EACCES); } } unlock_kernel(); d_add(dentry, inode); return NULL; } static int bfs_link(struct dentry *old, struct inode *dir, struct dentry *new) { struct inode *inode = old->d_inode; int err; lock_kernel(); err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino); if (err) { unlock_kernel(); return err; } inc_nlink(inode); inode->i_ctime = CURRENT_TIME_SEC; mark_inode_dirty(inode); atomic_inc(&inode->i_count); d_instantiate(new, inode); unlock_kernel(); return 0; } static int bfs_unlink(struct inode *dir, struct dentry *dentry) { int error = -ENOENT; struct inode *inode; struct buffer_head *bh; struct bfs_dirent *de; inode = dentry->d_inode; lock_kernel(); bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); if (!bh || (le16_to_cpu(de->ino) != inode->i_ino)) goto out_brelse; if (!inode->i_nlink) { printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id, inode->i_ino, inode->i_nlink); inode->i_nlink = 1; } de->ino = 0; mark_buffer_dirty(bh); dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; mark_inode_dirty(dir); inode->i_ctime = dir->i_ctime; inode_dec_link_count(inode); error = 0; out_brelse: brelse(bh); unlock_kernel(); return error; } static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct inode *old_inode, *new_inode; struct buffer_head *old_bh, *new_bh; struct bfs_dirent *old_de, *new_de; int error = -ENOENT; old_bh = new_bh = NULL; old_inode = old_dentry->d_inode; if (S_ISDIR(old_inode->i_mode)) return -EINVAL; lock_kernel(); old_bh = bfs_find_entry(old_dir, old_dentry->d_name.name, old_dentry->d_name.len, &old_de); if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino)) goto end_rename; error = -EPERM; new_inode = new_dentry->d_inode; new_bh = bfs_find_entry(new_dir, new_dentry->d_name.name, new_dentry->d_name.len, &new_de); if (new_bh && !new_inode) { brelse(new_bh); new_bh = NULL; } if (!new_bh) { error = bfs_add_entry(new_dir, new_dentry->d_name.name, new_dentry->d_name.len, old_inode->i_ino); if (error) goto end_rename; } old_de->ino = 0; old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC; mark_inode_dirty(old_dir); if (new_inode) { new_inode->i_ctime = CURRENT_TIME_SEC; inode_dec_link_count(new_inode); } mark_buffer_dirty(old_bh); error = 0; end_rename: unlock_kernel(); brelse(old_bh); brelse(new_bh); return error; } const struct inode_operations bfs_dir_inops = { .create = bfs_create, .lookup = bfs_lookup, .link = bfs_link, .unlink = bfs_unlink, .rename = bfs_rename, }; static int bfs_add_entry(struct inode *dir, const unsigned char *name, int namelen, int ino) { struct buffer_head *bh; struct bfs_dirent *de; int block, sblock, eblock, off, pos; int i; dprintf("name=%s, namelen=%d\n", name, namelen); if (!namelen) return -ENOENT; if (namelen > BFS_NAMELEN) return -ENAMETOOLONG; sblock = BFS_I(dir)->i_sblock; eblock = BFS_I(dir)->i_eblock; for (block = sblock; block <= eblock; block++) { bh = sb_bread(dir->i_sb, block); if (!bh) return -ENOSPC; for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) { de = (struct bfs_dirent *)(bh->b_data + off); if (!de->ino) { pos = (block - sblock) * BFS_BSIZE + off; if (pos >= dir->i_size) { dir->i_size += BFS_DIRENT_SIZE; dir->i_ctime = CURRENT_TIME_SEC; } dir->i_mtime = CURRENT_TIME_SEC; mark_inode_dirty(dir); de->ino = cpu_to_le16((u16)ino); for (i = 0; i < BFS_NAMELEN; i++) de->name[i] = (i < namelen) ? name[i] : 0; mark_buffer_dirty(bh); brelse(bh); return 0; } } brelse(bh); } return -ENOSPC; } static inline int bfs_namecmp(int len, const unsigned char *name, const char *buffer) { if ((len < BFS_NAMELEN) && buffer[len]) return 0; return !memcmp(name, buffer, len); } static struct buffer_head *bfs_find_entry(struct inode *dir, const unsigned char *name, int namelen, struct bfs_dirent **res_dir) { unsigned long block = 0, offset = 0; struct buffer_head *bh = NULL; struct bfs_dirent *de; *res_dir = NULL; if (namelen > BFS_NAMELEN) return NULL; while (block * BFS_BSIZE + offset < dir->i_size) { if (!bh) { bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block); if (!bh) { block++; continue; } } de = (struct bfs_dirent *)(bh->b_data + offset); offset += BFS_DIRENT_SIZE; if (le16_to_cpu(de->ino) && bfs_namecmp(namelen, name, de->name)) { *res_dir = de; return bh; } if (offset < bh->b_size) continue; brelse(bh); bh = NULL; offset = 0; block++; } brelse(bh); return NULL; }