1 files changed, 362 insertions, 0 deletions

diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
new file mode 100644
index 0000000..5a1e5ce
--- /dev/null
+++ b/fs/bfs/dir.c
@@ -0,0 +1,362 @@
+/*
+ *	fs/bfs/dir.c
+ *	BFS directory operations.
+ *	Copyright (C) 1999,2000  Tigran Aivazian <tigran@veritas.com>
+ */
+
+#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 char * name, int namelen, int ino);
+static struct buffer_head * bfs_find_entry(struct inode * dir, 
+	const 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_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, 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;	
+}
+
+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 = inode->i_blksize = 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->i_nlink--;
+		mark_inode_dirty(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 = le32_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;
+	}
+	inode->i_nlink++;
+	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 || 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_nlink--;
+	inode->i_ctime = dir->i_ctime;
+	mark_inode_dirty(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 || 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_nlink--;
+		new_inode->i_ctime = CURRENT_TIME_SEC;
+		mark_inode_dirty(new_inode);
+	}
+	mark_buffer_dirty(old_bh);
+	error = 0;
+
+end_rename:
+	unlock_kernel();
+	brelse(old_bh);
+	brelse(new_bh);
+	return error;
+}
+
+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 char * name, int namelen, int ino)
+{
+	struct buffer_head * bh;
+	struct bfs_dirent * de;
+	int block, sblock, eblock, off, eoff;
+	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;
+	eoff = dir->i_size % BFS_BSIZE;
+	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 (block==eblock && off>=eoff) {
+				/* Do not read/interpret the garbage in the end of eblock. */
+				de->ino = 0;
+			}
+			if (!de->ino) {
+				if ((block-sblock)*BFS_BSIZE + off >= 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 = 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 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 char * name, int namelen, struct bfs_dirent ** res_dir)
+{
+	unsigned long block, offset;
+	struct buffer_head * bh;
+	struct bfs_dirent * de;
+
+	*res_dir = NULL;
+	if (namelen > BFS_NAMELEN)
+		return NULL;
+	bh = NULL;
+	block = offset = 0;
+	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 (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;
+}