super.c

linux 内核源代码

#ifdef CONFIG_JFS_POSIX_ACL
	sb->s_flags |= MS_POSIXACL;
#endif

	if (newLVSize) {
		printk(KERN_ERR "resize option for remount only\n");
		return -EINVAL;
	}

	/*
	 * Initialize blocksize to 4K.
	 */
	sb_set_blocksize(sb, PSIZE);

	/*
	 * Set method vectors.
	 */
	sb->s_op = &jfs_super_operations;
	sb->s_export_op = &jfs_export_operations;

	/*
	 * Initialize direct-mapping inode/address-space
	 */
	inode = new_inode(sb);
	if (inode == NULL)
		goto out_kfree;
	inode->i_ino = 0;
	inode->i_nlink = 1;
	inode->i_size = sb->s_bdev->bd_inode->i_size;
	inode->i_mapping->a_ops = &jfs_metapage_aops;
	insert_inode_hash(inode);
	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);

	sbi->direct_inode = inode;

	rc = jfs_mount(sb);
	if (rc) {
		if (!silent) {
			jfs_err("jfs_mount failed w/return code = %d", rc);
		}
		goto out_mount_failed;
	}
	if (sb->s_flags & MS_RDONLY)
		sbi->log = NULL;
	else {
		rc = jfs_mount_rw(sb, 0);
		if (rc) {
			if (!silent) {
				jfs_err("jfs_mount_rw failed, return code = %d",
					rc);
			}
			goto out_no_rw;
		}
	}

	sb->s_magic = JFS_SUPER_MAGIC;

	inode = iget(sb, ROOT_I);
	if (!inode || is_bad_inode(inode))
		goto out_no_root;
	sb->s_root = d_alloc_root(inode);
	if (!sb->s_root)
		goto out_no_root;

	if (sbi->mntflag & JFS_OS2)
		sb->s_root->d_op = &jfs_ci_dentry_operations;

	/* logical blocks are represented by 40 bits in pxd_t, etc. */
	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
#if BITS_PER_LONG == 32
	/*
	 * Page cache is indexed by long.
	 * I would use MAX_LFS_FILESIZE, but it's only half as big
	 */
	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, sb->s_maxbytes);
#endif
	sb->s_time_gran = 1;
	return 0;

out_no_root:
	jfs_err("jfs_read_super: get root inode failed");
	if (inode)
		iput(inode);

out_no_rw:
	rc = jfs_umount(sb);
	if (rc) {
		jfs_err("jfs_umount failed with return code %d", rc);
	}
out_mount_failed:
	filemap_write_and_wait(sbi->direct_inode->i_mapping);
	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
	make_bad_inode(sbi->direct_inode);
	iput(sbi->direct_inode);
	sbi->direct_inode = NULL;
out_kfree:
	if (sbi->nls_tab)
		unload_nls(sbi->nls_tab);
	kfree(sbi);
	return -EINVAL;
}

static void jfs_write_super_lockfs(struct super_block *sb)
{
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	struct jfs_log *log = sbi->log;

	if (!(sb->s_flags & MS_RDONLY)) {
		txQuiesce(sb);
		lmLogShutdown(log);
		updateSuper(sb, FM_CLEAN);
	}
}

static void jfs_unlockfs(struct super_block *sb)
{
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	struct jfs_log *log = sbi->log;
	int rc = 0;

	if (!(sb->s_flags & MS_RDONLY)) {
		updateSuper(sb, FM_MOUNT);
		if ((rc = lmLogInit(log)))
			jfs_err("jfs_unlock failed with return code %d", rc);
		else
			txResume(sb);
	}
}

static int jfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
			   mnt);
}

static int jfs_sync_fs(struct super_block *sb, int wait)
{
	struct jfs_log *log = JFS_SBI(sb)->log;

	/* log == NULL indicates read-only mount */
	if (log) {
		jfs_flush_journal(log, wait);
		jfs_syncpt(log, 0);
	}

	return 0;
}

static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
	struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);

	if (sbi->uid != -1)
		seq_printf(seq, ",uid=%d", sbi->uid);
	if (sbi->gid != -1)
		seq_printf(seq, ",gid=%d", sbi->gid);
	if (sbi->umask != -1)
		seq_printf(seq, ",umask=%03o", sbi->umask);
	if (sbi->flag & JFS_NOINTEGRITY)
		seq_puts(seq, ",nointegrity");

#ifdef CONFIG_QUOTA
	if (sbi->flag & JFS_USRQUOTA)
		seq_puts(seq, ",usrquota");

	if (sbi->flag & JFS_GRPQUOTA)
		seq_puts(seq, ",grpquota");
#endif

	return 0;
}

#ifdef CONFIG_QUOTA

/* Read data from quotafile - avoid pagecache and such because we cannot afford
 * acquiring the locks... As quota files are never truncated and quota code
 * itself serializes the operations (and noone else should touch the files)
 * we don't have to be afraid of races */
static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
			      size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	sector_t blk = off >> sb->s_blocksize_bits;
	int err = 0;
	int offset = off & (sb->s_blocksize - 1);
	int tocopy;
	size_t toread;
	struct buffer_head tmp_bh;
	struct buffer_head *bh;
	loff_t i_size = i_size_read(inode);

	if (off > i_size)
		return 0;
	if (off+len > i_size)
		len = i_size-off;
	toread = len;
	while (toread > 0) {
		tocopy = sb->s_blocksize - offset < toread ?
				sb->s_blocksize - offset : toread;

		tmp_bh.b_state = 0;
		tmp_bh.b_size = 1 << inode->i_blkbits;
		err = jfs_get_block(inode, blk, &tmp_bh, 0);
		if (err)
			return err;
		if (!buffer_mapped(&tmp_bh))	/* A hole? */
			memset(data, 0, tocopy);
		else {
			bh = sb_bread(sb, tmp_bh.b_blocknr);
			if (!bh)
				return -EIO;
			memcpy(data, bh->b_data+offset, tocopy);
			brelse(bh);
		}
		offset = 0;
		toread -= tocopy;
		data += tocopy;
		blk++;
	}
	return len;
}

/* Write to quotafile */
static ssize_t jfs_quota_write(struct super_block *sb, int type,
			       const char *data, size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	sector_t blk = off >> sb->s_blocksize_bits;
	int err = 0;
	int offset = off & (sb->s_blocksize - 1);
	int tocopy;
	size_t towrite = len;
	struct buffer_head tmp_bh;
	struct buffer_head *bh;

	mutex_lock(&inode->i_mutex);
	while (towrite > 0) {
		tocopy = sb->s_blocksize - offset < towrite ?
				sb->s_blocksize - offset : towrite;

		tmp_bh.b_state = 0;
		tmp_bh.b_size = 1 << inode->i_blkbits;
		err = jfs_get_block(inode, blk, &tmp_bh, 1);
		if (err)
			goto out;
		if (offset || tocopy != sb->s_blocksize)
			bh = sb_bread(sb, tmp_bh.b_blocknr);
		else
			bh = sb_getblk(sb, tmp_bh.b_blocknr);
		if (!bh) {
			err = -EIO;
			goto out;
		}
		lock_buffer(bh);
		memcpy(bh->b_data+offset, data, tocopy);
		flush_dcache_page(bh->b_page);
		set_buffer_uptodate(bh);
		mark_buffer_dirty(bh);
		unlock_buffer(bh);
		brelse(bh);
		offset = 0;
		towrite -= tocopy;
		data += tocopy;
		blk++;
	}
out:
	if (len == towrite)
		return err;
	if (inode->i_size < off+len-towrite)
		i_size_write(inode, off+len-towrite);
	inode->i_version++;
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	mutex_unlock(&inode->i_mutex);
	return len - towrite;
}

#endif

static const struct super_operations jfs_super_operations = {
	.alloc_inode	= jfs_alloc_inode,
	.destroy_inode	= jfs_destroy_inode,
	.read_inode	= jfs_read_inode,
	.dirty_inode	= jfs_dirty_inode,
	.write_inode	= jfs_write_inode,
	.delete_inode	= jfs_delete_inode,
	.put_super	= jfs_put_super,
	.sync_fs	= jfs_sync_fs,
	.write_super_lockfs = jfs_write_super_lockfs,
	.unlockfs       = jfs_unlockfs,
	.statfs		= jfs_statfs,
	.remount_fs	= jfs_remount,
	.show_options	= jfs_show_options,
#ifdef CONFIG_QUOTA
	.quota_read	= jfs_quota_read,
	.quota_write	= jfs_quota_write,
#endif
};

static const struct export_operations jfs_export_operations = {
	.fh_to_dentry	= jfs_fh_to_dentry,
	.fh_to_parent	= jfs_fh_to_parent,
	.get_parent	= jfs_get_parent,
};

static struct file_system_type jfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "jfs",
	.get_sb		= jfs_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static void init_once(struct kmem_cache *cachep, void *foo)
{
	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;

	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
	init_rwsem(&jfs_ip->rdwrlock);
	mutex_init(&jfs_ip->commit_mutex);
	init_rwsem(&jfs_ip->xattr_sem);
	spin_lock_init(&jfs_ip->ag_lock);
	jfs_ip->active_ag = -1;
#ifdef CONFIG_JFS_POSIX_ACL
	jfs_ip->i_acl = JFS_ACL_NOT_CACHED;
	jfs_ip->i_default_acl = JFS_ACL_NOT_CACHED;
#endif
	inode_init_once(&jfs_ip->vfs_inode);
}

static int __init init_jfs_fs(void)
{
	int i;
	int rc;

	jfs_inode_cachep =
	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
			    init_once);
	if (jfs_inode_cachep == NULL)
		return -ENOMEM;

	/*
	 * Metapage initialization
	 */
	rc = metapage_init();
	if (rc) {
		jfs_err("metapage_init failed w/rc = %d", rc);
		goto free_slab;
	}

	/*
	 * Transaction Manager initialization
	 */
	rc = txInit();
	if (rc) {
		jfs_err("txInit failed w/rc = %d", rc);
		goto free_metapage;
	}

	/*
	 * I/O completion thread (endio)
	 */
	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
	if (IS_ERR(jfsIOthread)) {
		rc = PTR_ERR(jfsIOthread);
		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
		goto end_txmngr;
	}

	if (commit_threads < 1)
		commit_threads = num_online_cpus();
	if (commit_threads > MAX_COMMIT_THREADS)
		commit_threads = MAX_COMMIT_THREADS;

	for (i = 0; i < commit_threads; i++) {
		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
		if (IS_ERR(jfsCommitThread[i])) {
			rc = PTR_ERR(jfsCommitThread[i]);
			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
			commit_threads = i;
			goto kill_committask;
		}
	}

	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
	if (IS_ERR(jfsSyncThread)) {
		rc = PTR_ERR(jfsSyncThread);
		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
		goto kill_committask;
	}

#ifdef PROC_FS_JFS
	jfs_proc_init();
#endif

	return register_filesystem(&jfs_fs_type);

kill_committask:
	for (i = 0; i < commit_threads; i++)
		kthread_stop(jfsCommitThread[i]);
	kthread_stop(jfsIOthread);
end_txmngr:
	txExit();
free_metapage:
	metapage_exit();
free_slab:
	kmem_cache_destroy(jfs_inode_cachep);
	return rc;
}

static void __exit exit_jfs_fs(void)
{
	int i;

	jfs_info("exit_jfs_fs called");

	txExit();
	metapage_exit();

	kthread_stop(jfsIOthread);
	for (i = 0; i < commit_threads; i++)
		kthread_stop(jfsCommitThread[i]);
	kthread_stop(jfsSyncThread);
#ifdef PROC_FS_JFS
	jfs_proc_clean();
#endif
	unregister_filesystem(&jfs_fs_type);
	kmem_cache_destroy(jfs_inode_cachep);
}

module_init(init_jfs_fs)
module_exit(exit_jfs_fs)