ocfs2: fix a tiny race when running dirop_fileop_racer (f7a14f32) · Commits · 戴 / test

fs/ocfs2/namei.c

+94 −2

Original line number	Diff line number	Diff line
		@@ -991,6 +991,65 @@ leave:
		return status;
		}

		static int ocfs2_check_if_ancestor(struct ocfs2_super *osb,
		u64 src_inode_no, u64 dest_inode_no)
		{
		int ret = 0, i = 0;
		u64 parent_inode_no = 0;
		u64 child_inode_no = src_inode_no;
		struct inode *child_inode;

		#define MAX_LOOKUP_TIMES 32
		while (1) {
		child_inode = ocfs2_iget(osb, child_inode_no, 0, 0);
		if (IS_ERR(child_inode)) {
		ret = PTR_ERR(child_inode);
		break;
		}

		ret = ocfs2_inode_lock(child_inode, NULL, 0);
		if (ret < 0) {
		iput(child_inode);
		if (ret != -ENOENT)
		mlog_errno(ret);
		break;
		}

		ret = ocfs2_lookup_ino_from_name(child_inode, "..", 2,
		&parent_inode_no);
		ocfs2_inode_unlock(child_inode, 0);
		iput(child_inode);
		if (ret < 0) {
		ret = -ENOENT;
		break;
		}

		if (parent_inode_no == dest_inode_no) {
		ret = 1;
		break;
		}

		if (parent_inode_no == osb->root_inode->i_ino) {
		ret = 0;
		break;
		}

		child_inode_no = parent_inode_no;

		if (++i >= MAX_LOOKUP_TIMES) {
		mlog(ML_NOTICE, "max lookup times reached, filesystem "
		"may have nested directories, "
		"src inode: %llu, dest inode: %llu.\n",
		(unsigned long long)src_inode_no,
		(unsigned long long)dest_inode_no);
		ret = 0;
		break;
		}
		}

		return ret;
		}

		/*
		* The only place this should be used is rename!
		* if they have the same id, then the 1st one is the only one locked.
		@@ -1002,6 +1061,7 @@ static int ocfs2_double_lock(struct ocfs2_super *osb,
		struct inode *inode2)
		{
		int status;
		int inode1_is_ancestor, inode2_is_ancestor;
		struct ocfs2_inode_info *oi1 = OCFS2_I(inode1);
		struct ocfs2_inode_info *oi2 = OCFS2_I(inode2);
		struct buffer_head **tmpbh;
		@@ -1015,9 +1075,26 @@ static int ocfs2_double_lock(struct ocfs2_super *osb,
		if (*bh2)
		*bh2 = NULL;

		/* we always want to lock the one with the lower lockid first. */
		/* we always want to lock the one with the lower lockid first.
		* and if they are nested, we lock ancestor first */
		if (oi1->ip_blkno != oi2->ip_blkno) {
		if (oi1->ip_blkno < oi2->ip_blkno) {
		inode1_is_ancestor = ocfs2_check_if_ancestor(osb, oi2->ip_blkno,
		oi1->ip_blkno);
		if (inode1_is_ancestor < 0) {
		status = inode1_is_ancestor;
		goto bail;
		}

		inode2_is_ancestor = ocfs2_check_if_ancestor(osb, oi1->ip_blkno,
		oi2->ip_blkno);
		if (inode2_is_ancestor < 0) {
		status = inode2_is_ancestor;
		goto bail;
		}

		if ((inode1_is_ancestor == 1) \|\|
		(oi1->ip_blkno < oi2->ip_blkno &&
		inode2_is_ancestor == 0)) {
		/* switch id1 and id2 around */
		tmpbh = bh2;
		bh2 = bh1;
		@@ -1135,6 +1212,21 @@ static int ocfs2_rename(struct inode *old_dir,
		goto bail;
		}
		rename_lock = 1;

		/* here we cannot guarantee the inodes haven't just been
		* changed, so check if they are nested again */
		status = ocfs2_check_if_ancestor(osb, new_dir->i_ino,
		old_inode->i_ino);
		if (status < 0) {
		mlog_errno(status);
		goto bail;
		} else if (status == 1) {
		status = -EPERM;
		trace_ocfs2_rename_not_permitted(
		(unsigned long long)old_inode->i_ino,
		(unsigned long long)new_dir->i_ino);
		goto bail;
		}
		}

		/* if old and new are the same, this'll just do one lock. */

fs/ocfs2/ocfs2_trace.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -2292,6 +2292,8 @@ TRACE_EVENT(ocfs2_rename,
		__entry->new_len, __get_str(new_name))
		);

		DEFINE_OCFS2_ULL_ULL_EVENT(ocfs2_rename_not_permitted);

		TRACE_EVENT(ocfs2_rename_target_exists,
		TP_PROTO(int new_len, const char *new_name),
		TP_ARGS(new_len, new_name),

Admin message