namei.c

linux 内核源代码

	struct inode *iplist[4];
	struct tblock *tblk;
	s64 new_size = 0;
	int commit_flag;


	jfs_info("jfs_rename: %s %s", old_dentry->d_name.name,
		 new_dentry->d_name.name);

	old_ip = old_dentry->d_inode;
	new_ip = new_dentry->d_inode;

	if ((rc = get_UCSname(&old_dname, old_dentry)))
		goto out1;

	if ((rc = get_UCSname(&new_dname, new_dentry)))
		goto out2;

	/*
	 * Make sure source inode number is what we think it is
	 */
	rc = dtSearch(old_dir, &old_dname, &ino, &btstack, JFS_LOOKUP);
	if (rc || (ino != old_ip->i_ino)) {
		rc = -ENOENT;
		goto out3;
	}

	/*
	 * Make sure dest inode number (if any) is what we think it is
	 */
	rc = dtSearch(new_dir, &new_dname, &ino, &btstack, JFS_LOOKUP);
	if (rc == 0) {
		if ((new_ip == 0) || (ino != new_ip->i_ino)) {
			rc = -ESTALE;
			goto out3;
		}
	} else if (rc != -ENOENT)
		goto out3;
	else if (new_ip) {
		/* no entry exists, but one was expected */
		rc = -ESTALE;
		goto out3;
	}

	if (S_ISDIR(old_ip->i_mode)) {
		if (new_ip) {
			if (!dtEmpty(new_ip)) {
				rc = -ENOTEMPTY;
				goto out3;
			}
		} else if ((new_dir != old_dir) &&
			   (new_dir->i_nlink == JFS_LINK_MAX)) {
			rc = -EMLINK;
			goto out3;
		}
	} else if (new_ip) {
		IWRITE_LOCK(new_ip, RDWRLOCK_NORMAL);
		/* Init inode for quota operations. */
		DQUOT_INIT(new_ip);
	}

	/*
	 * The real work starts here
	 */
	tid = txBegin(new_dir->i_sb, 0);

	/*
	 * How do we know the locking is safe from deadlocks?
	 * The vfs does the hard part for us.  Any time we are taking nested
	 * commit_mutexes, the vfs already has i_mutex held on the parent.
	 * Here, the vfs has already taken i_mutex on both old_dir and new_dir.
	 */
	mutex_lock_nested(&JFS_IP(new_dir)->commit_mutex, COMMIT_MUTEX_PARENT);
	mutex_lock_nested(&JFS_IP(old_ip)->commit_mutex, COMMIT_MUTEX_CHILD);
	if (old_dir != new_dir)
		mutex_lock_nested(&JFS_IP(old_dir)->commit_mutex,
				  COMMIT_MUTEX_SECOND_PARENT);

	if (new_ip) {
		mutex_lock_nested(&JFS_IP(new_ip)->commit_mutex,
				  COMMIT_MUTEX_VICTIM);
		/*
		 * Change existing directory entry to new inode number
		 */
		ino = new_ip->i_ino;
		rc = dtModify(tid, new_dir, &new_dname, &ino,
			      old_ip->i_ino, JFS_RENAME);
		if (rc)
			goto out4;
		drop_nlink(new_ip);
		if (S_ISDIR(new_ip->i_mode)) {
			drop_nlink(new_ip);
			if (new_ip->i_nlink) {
				mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
				if (old_dir != new_dir)
					mutex_unlock(&JFS_IP(old_dir)->commit_mutex);
				mutex_unlock(&JFS_IP(old_ip)->commit_mutex);
				mutex_unlock(&JFS_IP(new_dir)->commit_mutex);
				if (!S_ISDIR(old_ip->i_mode) && new_ip)
					IWRITE_UNLOCK(new_ip);
				jfs_error(new_ip->i_sb,
					  "jfs_rename: new_ip->i_nlink != 0");
				return -EIO;
			}
			tblk = tid_to_tblock(tid);
			tblk->xflag |= COMMIT_DELETE;
			tblk->u.ip = new_ip;
		} else if (new_ip->i_nlink == 0) {
			assert(!test_cflag(COMMIT_Nolink, new_ip));
			/* free block resources */
			if ((new_size = commitZeroLink(tid, new_ip)) < 0) {
				txAbort(tid, 1);	/* Marks FS Dirty */
				rc = new_size;
				goto out4;
			}
			tblk = tid_to_tblock(tid);
			tblk->xflag |= COMMIT_DELETE;
			tblk->u.ip = new_ip;
		} else {
			new_ip->i_ctime = CURRENT_TIME;
			mark_inode_dirty(new_ip);
		}
	} else {
		/*
		 * Add new directory entry
		 */
		rc = dtSearch(new_dir, &new_dname, &ino, &btstack,
			      JFS_CREATE);
		if (rc) {
			jfs_err("jfs_rename didn't expect dtSearch to fail "
				"w/rc = %d", rc);
			goto out4;
		}

		ino = old_ip->i_ino;
		rc = dtInsert(tid, new_dir, &new_dname, &ino, &btstack);
		if (rc) {
			if (rc == -EIO)
				jfs_err("jfs_rename: dtInsert returned -EIO");
			goto out4;
		}
		if (S_ISDIR(old_ip->i_mode))
			inc_nlink(new_dir);
	}
	/*
	 * Remove old directory entry
	 */

	ino = old_ip->i_ino;
	rc = dtDelete(tid, old_dir, &old_dname, &ino, JFS_REMOVE);
	if (rc) {
		jfs_err("jfs_rename did not expect dtDelete to return rc = %d",
			rc);
		txAbort(tid, 1);	/* Marks Filesystem dirty */
		goto out4;
	}
	if (S_ISDIR(old_ip->i_mode)) {
		drop_nlink(old_dir);
		if (old_dir != new_dir) {
			/*
			 * Change inode number of parent for moved directory
			 */

			JFS_IP(old_ip)->i_dtroot.header.idotdot =
				cpu_to_le32(new_dir->i_ino);

			/* Linelock header of dtree */
			tlck = txLock(tid, old_ip,
				    (struct metapage *) &JFS_IP(old_ip)->bxflag,
				      tlckDTREE | tlckBTROOT | tlckRELINK);
			dtlck = (struct dt_lock *) & tlck->lock;
			ASSERT(dtlck->index == 0);
			lv = & dtlck->lv[0];
			lv->offset = 0;
			lv->length = 1;
			dtlck->index++;
		}
	}

	/*
	 * Update ctime on changed/moved inodes & mark dirty
	 */
	old_ip->i_ctime = CURRENT_TIME;
	mark_inode_dirty(old_ip);

	new_dir->i_ctime = new_dir->i_mtime = current_fs_time(new_dir->i_sb);
	mark_inode_dirty(new_dir);

	/* Build list of inodes modified by this transaction */
	ipcount = 0;
	iplist[ipcount++] = old_ip;
	if (new_ip)
		iplist[ipcount++] = new_ip;
	iplist[ipcount++] = old_dir;

	if (old_dir != new_dir) {
		iplist[ipcount++] = new_dir;
		old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
		mark_inode_dirty(old_dir);
	}

	/*
	 * Incomplete truncate of file data can
	 * result in timing problems unless we synchronously commit the
	 * transaction.
	 */
	if (new_size)
		commit_flag = COMMIT_SYNC;
	else
		commit_flag = 0;

	rc = txCommit(tid, ipcount, iplist, commit_flag);

      out4:
	txEnd(tid);
	if (new_ip)
		mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
	if (old_dir != new_dir)
		mutex_unlock(&JFS_IP(old_dir)->commit_mutex);
	mutex_unlock(&JFS_IP(old_ip)->commit_mutex);
	mutex_unlock(&JFS_IP(new_dir)->commit_mutex);

	while (new_size && (rc == 0)) {
		tid = txBegin(new_ip->i_sb, 0);
		mutex_lock(&JFS_IP(new_ip)->commit_mutex);
		new_size = xtTruncate_pmap(tid, new_ip, new_size);
		if (new_size < 0) {
			txAbort(tid, 1);
			rc = new_size;
		} else
			rc = txCommit(tid, 1, &new_ip, COMMIT_SYNC);
		txEnd(tid);
		mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
	}
	if (new_ip && (new_ip->i_nlink == 0))
		set_cflag(COMMIT_Nolink, new_ip);
      out3:
	free_UCSname(&new_dname);
      out2:
	free_UCSname(&old_dname);
      out1:
	if (new_ip && !S_ISDIR(new_ip->i_mode))
		IWRITE_UNLOCK(new_ip);
	/*
	 * Truncating the directory index table is not guaranteed.  It
	 * may need to be done iteratively
	 */
	if (test_cflag(COMMIT_Stale, old_dir)) {
		if (old_dir->i_size > 1)
			jfs_truncate_nolock(old_dir, 0);

		clear_cflag(COMMIT_Stale, old_dir);
	}

	jfs_info("jfs_rename: returning %d", rc);
	return rc;
}


/*
 * NAME:	jfs_mknod
 *
 * FUNCTION:	Create a special file (device)
 */
static int jfs_mknod(struct inode *dir, struct dentry *dentry,
		int mode, dev_t rdev)
{
	struct jfs_inode_info *jfs_ip;
	struct btstack btstack;
	struct component_name dname;
	ino_t ino;
	struct inode *ip;
	struct inode *iplist[2];
	int rc;
	tid_t tid;
	struct tblock *tblk;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	jfs_info("jfs_mknod: %s", dentry->d_name.name);

	if ((rc = get_UCSname(&dname, dentry)))
		goto out;

	ip = ialloc(dir, mode);
	if (IS_ERR(ip)) {
		rc = PTR_ERR(ip);
		goto out1;
	}
	jfs_ip = JFS_IP(ip);

	tid = txBegin(dir->i_sb, 0);

	mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);
	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);

	rc = jfs_init_acl(tid, ip, dir);
	if (rc)
		goto out3;

	rc = jfs_init_security(tid, ip, dir);
	if (rc) {
		txAbort(tid, 0);
		goto out3;
	}

	if ((rc = dtSearch(dir, &dname, &ino, &btstack, JFS_CREATE))) {
		txAbort(tid, 0);
		goto out3;
	}

	tblk = tid_to_tblock(tid);
	tblk->xflag |= COMMIT_CREATE;
	tblk->ino = ip->i_ino;
	tblk->u.ixpxd = JFS_IP(ip)->ixpxd;

	ino = ip->i_ino;
	if ((rc = dtInsert(tid, dir, &dname, &ino, &btstack))) {
		txAbort(tid, 0);
		goto out3;
	}

	ip->i_op = &jfs_file_inode_operations;
	jfs_ip->dev = new_encode_dev(rdev);
	init_special_inode(ip, ip->i_mode, rdev);

	insert_inode_hash(ip);
	mark_inode_dirty(ip);

	dir->i_ctime = dir->i_mtime = CURRENT_TIME;

	mark_inode_dirty(dir);

	iplist[0] = dir;
	iplist[1] = ip;
	rc = txCommit(tid, 2, iplist, 0);

      out3:
	txEnd(tid);
	mutex_unlock(&JFS_IP(ip)->commit_mutex);
	mutex_unlock(&JFS_IP(dir)->commit_mutex);
	if (rc) {
		free_ea_wmap(ip);
		ip->i_nlink = 0;
		iput(ip);
	} else
		d_instantiate(dentry, ip);

      out1:
	free_UCSname(&dname);

      out:
	jfs_info("jfs_mknod: returning %d", rc);
	return rc;
}

static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd)
{
	struct btstack btstack;
	ino_t inum;
	struct inode *ip;
	struct component_name key;
	const char *name = dentry->d_name.name;
	int len = dentry->d_name.len;
	int rc;

	jfs_info("jfs_lookup: name = %s", name);

	if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
		dentry->d_op = &jfs_ci_dentry_operations;

	if ((name[0] == '.') && (len == 1))
		inum = dip->i_ino;
	else if (strcmp(name, "..") == 0)
		inum = PARENT(dip);
	else {
		if ((rc = get_UCSname(&key, dentry)))
			return ERR_PTR(rc);
		rc = dtSearch(dip, &key, &inum, &btstack, JFS_LOOKUP);
		free_UCSname(&key);
		if (rc == -ENOENT) {
			d_add(dentry, NULL);
			return ERR_PTR(0);
		} else if (rc) {
			jfs_err("jfs_lookup: dtSearch returned %d", rc);
			return ERR_PTR(rc);
		}
	}

	ip = iget(dip->i_sb, inum);
	if (ip == NULL || is_bad_inode(ip)) {
		jfs_err("jfs_lookup: iget failed on inum %d", (uint) inum);
		if (ip)
			iput(ip);
		return ERR_PTR(-EACCES);
	}

	dentry = d_splice_alias(ip, dentry);

	if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
		dentry->d_op = &jfs_ci_dentry_operations;

	return dentry;
}

static struct inode *jfs_nfs_get_inode(struct super_block *sb,
		u64 ino, u32 generation)
{
	struct inode *inode;

	if (ino == 0)
		return ERR_PTR(-ESTALE);
	inode = iget(sb, ino);
	if (inode == NULL)
		return ERR_PTR(-ENOMEM);

	if (is_bad_inode(inode) ||
	    (generation && inode->i_generation != generation)) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return inode;
}

struct dentry *jfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    jfs_nfs_get_inode);
}

struct dentry *jfs_fh_to_parent(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    jfs_nfs_get_inode);
}

struct dentry *jfs_get_parent(struct dentry *dentry)
{
	struct super_block *sb = dentry->d_inode->i_sb;
	struct dentry *parent = ERR_PTR(-ENOENT);
	struct inode *inode;
	unsigned long parent_ino;

	parent_ino =
		le32_to_cpu(JFS_IP(dentry->d_inode)->i_dtroot.header.idotdot);
	inode = iget(sb, parent_ino);
	if (inode) {
		if (is_bad_inode(inode)) {
			iput(inode);
			parent = ERR_PTR(-EACCES);
		} else {
			parent = d_alloc_anon(inode);
			if (!parent) {
				parent = ERR_PTR(-ENOMEM);
				iput(inode);
			}
		}
	}

	return parent;
}

const struct inode_operations jfs_dir_inode_operations = {
	.create		= jfs_create,
	.lookup		= jfs_lookup,
	.link		= jfs_link,
	.unlink		= jfs_unlink,
	.symlink	= jfs_symlink,
	.mkdir		= jfs_mkdir,
	.rmdir		= jfs_rmdir,
	.mknod		= jfs_mknod,
	.rename		= jfs_rename,
	.setxattr	= jfs_setxattr,
	.getxattr	= jfs_getxattr,
	.listxattr	= jfs_listxattr,
	.removexattr	= jfs_removexattr,
#ifdef CONFIG_JFS_POSIX_ACL
	.setattr	= jfs_setattr,
	.permission	= jfs_permission,
#endif
};

const struct file_operations jfs_dir_operations = {
	.read		= generic_read_dir,
	.readdir	= jfs_readdir,
	.fsync		= jfs_fsync,
	.ioctl		= jfs_ioctl,
};

static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
{
	unsigned long hash;
	int i;

	hash = init_name_hash();
	for (i=0; i < this->len; i++)
		hash = partial_name_hash(tolower(this->name[i]), hash);
	this->hash = end_name_hash(hash);

	return 0;
}

static int jfs_ci_compare(struct dentry *dir, struct qstr *a, struct qstr *b)
{
	int i, result = 1;

	if (a->len != b->len)
		goto out;
	for (i=0; i < a->len; i++) {
		if (tolower(a->name[i]) != tolower(b->name[i]))
			goto out;
	}
	result = 0;

	/*
	 * We want creates to preserve case.  A negative dentry, a, that
	 * has a different case than b may cause a new entry to be created
	 * with the wrong case.  Since we can't tell if a comes from a negative
	 * dentry, we blindly replace it with b.  This should be harmless if
	 * a is not a negative dentry.
	 */
	memcpy((unsigned char *)a->name, b->name, a->len);
out:
	return result;
}

struct dentry_operations jfs_ci_dentry_operations =
{
	.d_hash = jfs_ci_hash,
	.d_compare = jfs_ci_compare,
};