inode.c

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/*
 *  linux/fs/affs/inode.c
 *
 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
 *
 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
 *
 *  (C) 1992  Eric Youngdale Modified for ISO9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 */

#include <asm/div64.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/affs_fs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <linux/genhd.h>
#include <linux/amigaffs.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/module.h>

extern struct inode_operations affs_symlink_inode_operations;
extern struct timezone sys_tz;

void
affs_read_inode(struct inode *inode)
{
	struct super_block	*sb = inode->i_sb;
	struct buffer_head	*bh;
	struct affs_head	*head;
	struct affs_tail	*tail;
	u32			 block;
	u32			 size;
	u32			 prot;
	u16			 id;

	pr_debug("AFFS: read_inode(%lu)\n",inode->i_ino);

	block = inode->i_ino;
	bh = affs_bread(sb, block);
	if (!bh) {
		affs_warning(sb, "read_inode", "Cannot read block %d", block);
		goto bad_inode;
	}
	if (affs_checksum_block(sb, bh) || be32_to_cpu(AFFS_HEAD(bh)->ptype) != T_SHORT) {
		affs_warning(sb,"read_inode",
			   "Checksum or type (ptype=%d) error on inode %d",
			   AFFS_HEAD(bh)->ptype, block);
		goto bad_inode;
	}

	head = AFFS_HEAD(bh);
	tail = AFFS_TAIL(sb, bh);
	prot = be32_to_cpu(tail->protect);

	inode->i_size = 0;
	inode->i_nlink = 1;
	inode->i_mode = 0;
	memset(AFFS_INODE, 0, sizeof(*AFFS_INODE));
	init_MUTEX(&AFFS_INODE->i_link_lock);
	init_MUTEX(&AFFS_INODE->i_ext_lock);
	AFFS_INODE->i_extcnt = 1;
	AFFS_INODE->i_ext_last = ~1;
	AFFS_INODE->i_protect = prot;

	if (AFFS_SB->s_flags & SF_SETMODE)
		inode->i_mode = AFFS_SB->s_mode;
	else
		inode->i_mode = prot_to_mode(prot);

	id = be16_to_cpu(tail->uid);
	if (id == 0 || AFFS_SB->s_flags & SF_SETUID)
		inode->i_uid = AFFS_SB->s_uid;
	else if (id == 0xFFFF && AFFS_SB->s_flags & SF_MUFS)
		inode->i_uid = 0;
	else
		inode->i_uid = id;

	id = be16_to_cpu(tail->gid);
	if (id == 0 || AFFS_SB->s_flags & SF_SETGID)
		inode->i_gid = AFFS_SB->s_gid;
	else if (id == 0xFFFF && AFFS_SB->s_flags & SF_MUFS)
		inode->i_gid = 0;
	else
		inode->i_gid = id;

	switch (be32_to_cpu(tail->stype)) {
	case ST_ROOT:
		inode->i_uid = AFFS_SB->s_uid;
		inode->i_gid = AFFS_SB->s_gid;
		/* fall through */
	case ST_USERDIR:
		if (be32_to_cpu(tail->stype) == ST_USERDIR ||
		    AFFS_SB->s_flags & SF_SETMODE) {
			if (inode->i_mode & S_IRUSR)
				inode->i_mode |= S_IXUSR;
			if (inode->i_mode & S_IRGRP)
				inode->i_mode |= S_IXGRP;
			if (inode->i_mode & S_IROTH)
				inode->i_mode |= S_IXOTH;
			inode->i_mode |= S_IFDIR;
		} else
			inode->i_mode = S_IRUGO | S_IXUGO | S_IWUSR | S_IFDIR;
		if (tail->link_chain)
			inode->i_nlink = 2;
		/* Maybe it should be controlled by mount parameter? */
		//inode->i_mode |= S_ISVTX;
		inode->i_op = &affs_dir_inode_operations;
		inode->i_fop = &affs_dir_operations;
		break;
	case ST_LINKDIR:
#if 0
		affs_warning(sb, "read_inode", "inode is LINKDIR");
		goto bad_inode;
#else
		inode->i_mode |= S_IFDIR;
		inode->i_op = NULL;
		inode->i_fop = NULL;
		break;
#endif
	case ST_LINKFILE:
		affs_warning(sb, "read_inode", "inode is LINKFILE");
		goto bad_inode;
	case ST_FILE:
		size = be32_to_cpu(tail->size);
		inode->i_mode |= S_IFREG;
		AFFS_INODE->mmu_private = inode->i_size = size;
		if (inode->i_size) {
			AFFS_INODE->i_blkcnt = (size - 1) /
					       AFFS_SB->s_data_blksize + 1;
			AFFS_INODE->i_extcnt = (AFFS_INODE->i_blkcnt - 1) /
					       AFFS_SB->s_hashsize + 1;
		}
		if (tail->link_chain)
			inode->i_nlink = 2;
		inode->i_mapping->a_ops = (AFFS_SB->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
		inode->i_op = &affs_file_inode_operations;
		inode->i_fop = &affs_file_operations;
		break;
	case ST_SOFTLINK:
		inode->i_mode |= S_IFLNK;
		inode->i_op = &affs_symlink_inode_operations;
		inode->i_data.a_ops = &affs_symlink_aops;
		break;
	}

	inode->i_mtime = inode->i_atime = inode->i_ctime
		       = (be32_to_cpu(tail->change.days) * (24 * 60 * 60) +
		         be32_to_cpu(tail->change.mins) * 60 +
			 be32_to_cpu(tail->change.ticks) / 50 +
			 ((8 * 365 + 2) * 24 * 60 * 60)) +
			 sys_tz.tz_minuteswest * 60;
	affs_brelse(bh);
	return;

bad_inode:
	make_bad_inode(inode);
	affs_brelse(bh);
	return;
}

void
affs_write_inode(struct inode *inode, int unused)
{
	struct super_block	*sb = inode->i_sb;
	struct buffer_head	*bh;
	struct affs_tail	*tail;
	uid_t			 uid;
	gid_t			 gid;

	pr_debug("AFFS: write_inode(%lu)\n",inode->i_ino);

	if (!inode->i_nlink)
		// possibly free block
		return;
	lock_kernel();
	bh = affs_bread(sb, inode->i_ino);
	if (!bh) {
		affs_error(sb,"write_inode","Cannot read block %lu",inode->i_ino);
		unlock_kernel();
		return;
	}
	tail = AFFS_TAIL(sb, bh);
	if (tail->stype == be32_to_cpu(ST_ROOT)) {
		secs_to_datestamp(inode->i_mtime,&AFFS_ROOT_TAIL(sb, bh)->root_change);
	} else {
		tail->protect = cpu_to_be32(AFFS_INODE->i_protect);
		tail->size = cpu_to_be32(inode->i_size);
		secs_to_datestamp(inode->i_mtime,&tail->change);
		if (!(inode->i_ino == AFFS_SB->s_root_block)) {
			uid = inode->i_uid;
			gid = inode->i_gid;
			if (sb->u.affs_sb.s_flags & SF_MUFS) {
				if (inode->i_uid == 0 || inode->i_uid == 0xFFFF)
					uid = inode->i_uid ^ ~0;
				if (inode->i_gid == 0 || inode->i_gid == 0xFFFF)
					gid = inode->i_gid ^ ~0;
			}
			if (!(sb->u.affs_sb.s_flags & SF_SETUID))
				tail->uid = cpu_to_be16(uid);
			if (!(sb->u.affs_sb.s_flags & SF_SETGID))
				tail->gid = cpu_to_be16(gid);
		}
	}
	affs_fix_checksum(sb, bh);
	mark_buffer_dirty_inode(bh, inode);
	affs_brelse(bh);
	unlock_kernel();
}

int
affs_notify_change(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	int error;

	pr_debug("AFFS: notify_change(%lu,0x%x)\n",inode->i_ino,attr->ia_valid);

	error = inode_change_ok(inode,attr);
	if (error)
		goto out;

	if (((attr->ia_valid & ATTR_UID) && (inode->i_sb->u.affs_sb.s_flags & SF_SETUID)) ||
	    ((attr->ia_valid & ATTR_GID) && (inode->i_sb->u.affs_sb.s_flags & SF_SETGID)) ||
	    ((attr->ia_valid & ATTR_MODE) &&
	     (inode->i_sb->u.affs_sb.s_flags & (SF_SETMODE | SF_IMMUTABLE)))) {
		if (!(inode->i_sb->u.affs_sb.s_flags & SF_QUIET))
			error = -EPERM;
		goto out;
	}

	inode_setattr(inode, attr);
	if (!error && (attr->ia_valid & ATTR_MODE))
		mode_to_prot(inode);
out:
	return error;
}

void
affs_put_inode(struct inode *inode)
{
	pr_debug("AFFS: put_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
	lock_kernel();
	affs_free_prealloc(inode);
	if (atomic_read(&inode->i_count) == 1) {
		if (inode->i_size != AFFS_INODE->mmu_private)
			affs_truncate(inode);
		//if (inode->i_nlink)
		//	affs_clear_inode(inode);
	}
	unlock_kernel();
}

void
affs_delete_inode(struct inode *inode)
{
	pr_debug("AFFS: delete_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
	lock_kernel();
	inode->i_size = 0;
	if (S_ISREG(inode->i_mode))
		affs_truncate(inode);
	clear_inode(inode);
	affs_free_block(inode->i_sb, inode->i_ino);
	unlock_kernel();
}

void
affs_clear_inode(struct inode *inode)
{
	unsigned long cache_page = (unsigned long) inode->u.affs_i.i_lc;

	pr_debug("AFFS: clear_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
	if (cache_page) {
		pr_debug("AFFS: freeing ext cache\n");
		inode->u.affs_i.i_lc = NULL;
		inode->u.affs_i.i_ac = NULL;
		free_page(cache_page);
	}
	affs_brelse(AFFS_INODE->i_ext_bh);
	AFFS_INODE->i_ext_last = ~1;
	AFFS_INODE->i_ext_bh = NULL;
}

struct inode *
affs_new_inode(struct inode *dir)
{
	struct super_block	*sb = dir->i_sb;
	struct inode		*inode;
	u32			 block;
	struct buffer_head	*bh;

	if (!(inode = new_inode(sb)))
		goto err_inode;

	if (!(block = affs_alloc_block(dir, dir->i_ino)))
		goto err_block;

	bh = affs_getzeroblk(sb, block);
	if (!bh)
		goto err_bh;
	mark_buffer_dirty_inode(bh, inode);
	affs_brelse(bh);

	inode->i_uid     = current->fsuid;
	inode->i_gid     = current->fsgid;
	inode->i_ino     = block;
	inode->i_nlink   = 1;
	inode->i_mtime   = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	memset(AFFS_INODE, 0, sizeof(*AFFS_INODE));
	AFFS_INODE->i_extcnt = 1;
	AFFS_INODE->i_ext_last = ~1;
	init_MUTEX(&AFFS_INODE->i_link_lock);
	init_MUTEX(&AFFS_INODE->i_ext_lock);

	insert_inode_hash(inode);

	return inode;

err_bh:
	affs_free_block(sb, block);
err_block:
	iput(inode);
err_inode:
	return NULL;
}

/*
 * Add an entry to a directory. Create the header block
 * and insert it into the hash table.
 */

int
affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *inode_bh = NULL;
	struct buffer_head *bh = NULL;
	u32 block = 0;
	int retval;

	pr_debug("AFFS: add_entry(dir=%u, inode=%u, \"%*s\", type=%d)\n", (u32)dir->i_ino,
	         (u32)inode->i_ino, (int)dentry->d_name.len, dentry->d_name.name, type);

	retval = -EIO;
	bh = affs_bread(sb, inode->i_ino);
	if (!bh)
		goto done;

	affs_lock_link(inode);
	switch (type) {
	case ST_LINKFILE:
	case ST_LINKDIR:
		inode_bh = bh;
		retval = -ENOSPC;
		block = affs_alloc_block(dir, dir->i_ino);
		if (!block)
			goto err;
		retval = -EIO;
		bh = affs_getzeroblk(sb, block);
		if (!bh)
			goto err;
		break;
	default:
		break;
	}

	AFFS_HEAD(bh)->ptype = cpu_to_be32(T_SHORT);
	AFFS_HEAD(bh)->key = cpu_to_be32(bh->b_blocknr);
	affs_copy_name(AFFS_TAIL(sb, bh)->name, dentry);
	AFFS_TAIL(sb, bh)->stype = cpu_to_be32(type);
	AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);

	if (inode_bh) {
		u32 chain;
	       	chain = AFFS_TAIL(sb, inode_bh)->link_chain;
		AFFS_TAIL(sb, bh)->original = cpu_to_be32(inode->i_ino);
		AFFS_TAIL(sb, bh)->link_chain = chain;
		AFFS_TAIL(sb, inode_bh)->link_chain = cpu_to_be32(block);
		affs_adjust_checksum(inode_bh, block - be32_to_cpu(chain));
		mark_buffer_dirty_inode(inode_bh, inode);
		inode->i_nlink = 2;
		atomic_inc(&inode->i_count);
	}
	affs_fix_checksum(sb, bh);
	mark_buffer_dirty_inode(bh, inode);
	dentry->d_fsdata = (void *)bh->b_blocknr;

	affs_lock_dir(dir);
	retval = affs_insert_hash(dir, bh);
	mark_buffer_dirty_inode(bh, inode);
	affs_unlock_dir(dir);
	affs_unlock_link(inode);

	d_instantiate(dentry, inode);
done:
	affs_brelse(inode_bh);
	affs_brelse(bh);
	return retval;
err:
	if (block)
		affs_free_block(sb, block);
	affs_unlock_link(inode);
	goto done;
}
MODULE_LICENSE("GPL");