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Commit 5441ae5e authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Eric Van Hensbergen
Browse files

fs/9p: Add fid before dentry instantiation 



d_instantiate marks the dentry positive. So a parallel lookup and mkdir of
the directory can find dentry that doesn't have fid attached. This can result
in both the code path doing v9fs_fid_add which results in v9fs_dentry leak.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent ddf28352

fs/9p/vfs_inode.c

+1 −3
Original line number Diff line number Diff line
@@ -645,13 +645,11 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 
		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);

		goto error;

	}

	d_instantiate(dentry, inode);

	err = v9fs_fid_add(dentry, fid);

	if (err < 0)

		goto error;



	d_instantiate(dentry, inode);

	return ofid;



error:

	if (ofid)

		p9_client_clunk(ofid);

fs/9p/vfs_inode_dotl.c

+4 −4
Original line number Diff line number Diff line
@@ -281,10 +281,10 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, 
		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);

		goto error;

	}

	d_instantiate(dentry, inode);

	err = v9fs_fid_add(dentry, fid);

	if (err < 0)

		goto error;

	d_instantiate(dentry, inode);



	/* Now set the ACL based on the default value */

	v9fs_set_create_acl(dentry, &dacl, &pacl);
@@ -403,10 +403,10 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir, 
				err);

			goto error;

		}

		d_instantiate(dentry, inode);

		err = v9fs_fid_add(dentry, fid);

		if (err < 0)

			goto error;

		d_instantiate(dentry, inode);

		fid = NULL;

	} else {

		/*
@@ -657,10 +657,10 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry, 
					err);

			goto error;

		}

		d_instantiate(dentry, inode);

		err = v9fs_fid_add(dentry, fid);

		if (err < 0)

			goto error;

		d_instantiate(dentry, inode);

		fid = NULL;

	} else {

		/* Not in cached mode. No need to populate inode with stat */
@@ -810,10 +810,10 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode, 
				err);

			goto error;

		}

		d_instantiate(dentry, inode);

		err = v9fs_fid_add(dentry, fid);

		if (err < 0)

			goto error;

		d_instantiate(dentry, inode);

		fid = NULL;

	} else {

		/*