Merge branch 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs inode type handling updates from Al Viro:
 "We should never change the type bits of ->i_mode or the method tables
  (->i_op and ->i_fop) of a live inode.

  Unfortunately, not all filesystems took care to prevent that"

* 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  spufs: fix bogosity in S_ISGID handling
  9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"
  openpromfs: don't do unlock_new_inode() until the new inode is set up
  hostfs_mknod(): don't bother with init_special_inode()
  cifs: have cifs_fattr_to_inode() refuse to change type on live inode
  cifs: have ->mkdir() handle race with another client sanely
  do_cifs_create(): don't set ->i_mode of something we had not created
  gfs2: be careful with inode refresh
  ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode
  orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap...
  vboxsf: don't allow to change the inode type
  afs: Fix updating of i_mode due to 3rd party change
  ceph: don't allow type or device number to change on non-I_NEW inodes
  ceph: fix up error handling with snapdirs
  new helper: inode_wrong_type()

1 files changed, 36 insertions, 5 deletions

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 156f849f5385..689e3ffd29d7 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -78,9 +78,21 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 	struct inode *inode = ceph_get_inode(parent->i_sb, vino);
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
-	BUG_ON(!S_ISDIR(parent->i_mode));
 	if (IS_ERR(inode))
 		return inode;
+
+	if (!S_ISDIR(parent->i_mode)) {
+		pr_warn_once("bad snapdir parent type (mode=0%o)\n",
+			     parent->i_mode);
+		return ERR_PTR(-ENOTDIR);
+	}
+
+	if (!(inode->i_state & I_NEW) && !S_ISDIR(inode->i_mode)) {
+		pr_warn_once("bad snapdir inode type (mode=0%o)\n",
+			     inode->i_mode);
+		return ERR_PTR(-ENOTDIR);
+	}
+
 	inode->i_mode = parent->i_mode;
 	inode->i_uid = parent->i_uid;
 	inode->i_gid = parent->i_gid;
@@ -757,11 +769,32 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 	bool queue_trunc = false;
 	bool new_version = false;
 	bool fill_inline = false;
+	umode_t mode = le32_to_cpu(info->mode);
+	dev_t rdev = le32_to_cpu(info->rdev);
 
 	dout("%s %p ino %llx.%llx v %llu had %llu\n", __func__,
 	     inode, ceph_vinop(inode), le64_to_cpu(info->version),
 	     ci->i_version);
 
+	/* Once I_NEW is cleared, we can't change type or dev numbers */
+	if (inode->i_state & I_NEW) {
+		inode->i_mode = mode;
+	} else {
+		if (inode_wrong_type(inode, mode)) {
+			pr_warn_once("inode type changed! (ino %llx.%llx is 0%o, mds says 0%o)\n",
+				     ceph_vinop(inode), inode->i_mode, mode);
+			return -ESTALE;
+		}
+
+		if ((S_ISCHR(mode) || S_ISBLK(mode)) && inode->i_rdev != rdev) {
+			pr_warn_once("dev inode rdev changed! (ino %llx.%llx is %u:%u, mds says %u:%u)\n",
+				     ceph_vinop(inode), MAJOR(inode->i_rdev),
+				     MINOR(inode->i_rdev), MAJOR(rdev),
+				     MINOR(rdev));
+			return -ESTALE;
+		}
+	}
+
 	info_caps = le32_to_cpu(info->cap.caps);
 
 	/* prealloc new cap struct */
@@ -815,8 +848,6 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 	issued |= __ceph_caps_dirty(ci);
 	new_issued = ~issued & info_caps;
 
-	/* update inode */
-	inode->i_rdev = le32_to_cpu(info->rdev);
 	/* directories have fl_stripe_unit set to zero */
 	if (le32_to_cpu(info->layout.fl_stripe_unit))
 		inode->i_blkbits =
@@ -828,7 +859,7 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 
 	if ((new_version || (new_issued & CEPH_CAP_AUTH_SHARED)) &&
 	    (issued & CEPH_CAP_AUTH_EXCL) == 0) {
-		inode->i_mode = le32_to_cpu(info->mode);
+		inode->i_mode = mode;
 		inode->i_uid = make_kuid(&init_user_ns, le32_to_cpu(info->uid));
 		inode->i_gid = make_kgid(&init_user_ns, le32_to_cpu(info->gid));
 		dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
@@ -926,7 +957,7 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 	case S_IFCHR:
 	case S_IFSOCK:
 		inode->i_blkbits = PAGE_SHIFT;
-		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+		init_special_inode(inode, inode->i_mode, rdev);
 		inode->i_op = &ceph_file_iops;
 		break;
 	case S_IFREG: