fs/bfs/dir.c - fp2-dev/kernel/msm - Gitiles

 /*
  *	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;
 }
	/*
	* 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;
	}