xfs: split new inode creation into two pieces

There are two parts to initializing a newly allocated inode: setting up
the incore structures, and initializing the new inode core based on the
parent inode and the current user's environment.  The initialization
code is not specific to the kernel, so we would like to share that with
userspace by hoisting it to libxfs.  Therefore, split xfs_icreate into
separate functions to prepare for the next few patches.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 14c81f227c5b..f8d5ed7aedde 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -1946,6 +1946,21 @@ retry:
 		}
 		return -ENOSPC;
 	}
+
+	/*
+	 * Protect against obviously corrupt allocation btree records. Later
+	 * xfs_iget checks will catch re-allocation of other active in-memory
+	 * and on-disk inodes. If we don't catch reallocating the parent inode
+	 * here we will deadlock in xfs_iget() so we have to do these checks
+	 * first.
+	 */
+	if (ino == parent || !xfs_verify_dir_ino(mp, ino)) {
+		xfs_alert(mp, "Allocated a known in-use inode 0x%llx!", ino);
+		xfs_agno_mark_sick(mp, XFS_INO_TO_AGNO(mp, ino),
+				XFS_SICK_AG_INOBT);
+		return -EFSCORRUPTED;
+	}
+
 	*new_ino = ino;
 	return 0;
 }