[12/26] libxfs: split new inode creation into two pieces

Commit Message

Darrick J. Wong Dec. 30, 2022, 10:19 p.m. UTC

From: Darrick J. Wong <[e-mail]>

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 <[e-mail]>
---
 libxfs/inode.c      |   42 ++++++++++++++++++++++++++----------------
 libxfs/xfs_ialloc.c |   20 ++++++++++++++++++--
 2 files changed, 44 insertions(+), 18 deletions(-)

Patch

diff --git a/libxfs/inode.c b/libxfs/inode.c
index 9835c708021..44d889f3f0f 100644
--- a/libxfs/inode.c
+++ b/libxfs/inode.c
@@ -73,28 +73,17 @@  xfs_inode_inherit_flags2(
 		ip->i_diflags2 |= XFS_DIFLAG2_DAX;
 }
 
-/*
- * Initialise a newly allocated inode and return the in-core inode to the
- * caller locked exclusively.
- */
-static int
-libxfs_icreate(
+/* Initialise an inode's attributes. */
+static void
+xfs_inode_init(
 	struct xfs_trans	*tp,
-	xfs_ino_t		ino,
 	const struct xfs_icreate_args *args,
-	struct xfs_inode	**ipp)
+	struct xfs_inode	*ip)
 {
 	struct xfs_inode	*pip = args->pip;
-	struct xfs_inode	*ip;
 	unsigned int		flags;
 	int			times = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG |
 					XFS_ICHGTIME_ACCESS;
-	int			error;
-
-	error = libxfs_iget(tp->t_mountp, tp, ino, 0, &ip);
-	if (error != 0)
-		return error;
-	ASSERT(ip != NULL);
 
 	VFS_I(ip)->i_mode = args->mode;
 	set_nlink(VFS_I(ip), args->nlink);
@@ -154,7 +143,28 @@  libxfs_icreate(
 	 */
 	xfs_trans_ijoin(tp, ip, 0);
 	xfs_trans_log_inode(tp, ip, flags);
-	*ipp = ip;
+}
+
+/*
+ * Initialise a newly allocated inode and return the in-core inode to the
+ * caller locked exclusively.
+ */
+static int
+libxfs_icreate(
+	struct xfs_trans	*tp,
+	xfs_ino_t		ino,
+	const struct xfs_icreate_args *args,
+	struct xfs_inode	**ipp)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	int			error;
+
+	error = libxfs_iget(mp, tp, ino, 0, ipp);
+	if (error)
+		return error;
+
+	ASSERT(*ipp != NULL);
+	xfs_inode_init(tp, args, *ipp);
 	return 0;
 }
 
diff --git a/libxfs/xfs_ialloc.c b/libxfs/xfs_ialloc.c
index 3d55f5d1f46..9ce36b2cd8d 100644
--- a/libxfs/xfs_ialloc.c
+++ b/libxfs/xfs_ialloc.c
@@ -1865,9 +1865,25 @@  xfs_dialloc(
 		}
 		xfs_perag_put(pag);
 	}
+	if (error)
+		goto out;
 
-	if (!error)
-		*new_ino = ino;
+	/*
+	 * 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_ag_mark_sick(pag, XFS_SICK_AG_INOBT);
+		error = -EFSCORRUPTED;
+		goto out;
+	}
+
+	*new_ino = ino;
+out:
 	xfs_perag_put(pag);
 	return error;
 }