diff mbox series

[01/18] xfsprogs: zero inode fork buffer at allocation

Message ID 20220518001227.1779324-2-allison.henderson@oracle.com (mailing list archive)
State Superseded
Headers show
Series xfsprogs: Port larp, enable injects and log print for attri/d | expand

Commit Message

Allison Henderson May 18, 2022, 12:12 a.m. UTC 
From: Dave Chinner <dchinner@redhat.com>

Source kernel commit: cb512c921639613ce03f87e62c5e93ed9fe8c84d

When we first allocate or resize an inline inode fork, we round up
the allocation to 4 byte alingment to make journal alignment
constraints. We don't clear the unused bytes, so we can copy up to
three uninitialised bytes into the journal. Zero those bytes so we
only ever copy zeros into the journal.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
 libxfs/xfs_inode_fork.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/libxfs/xfs_inode_fork.c b/libxfs/xfs_inode_fork.c
index d6ac13eea764..a2af6d71948e 100644
--- a/libxfs/xfs_inode_fork.c
+++ b/libxfs/xfs_inode_fork.c
@@ -48,8 +48,13 @@  xfs_init_local_fork(
 		mem_size++;
 
 	if (size) {
+		/*
+		 * As we round up the allocation here, we need to ensure the
+		 * bytes we don't copy data into are zeroed because the log
+		 * vectors still copy them into the journal.
+		 */
 		real_size = roundup(mem_size, 4);
-		ifp->if_u1.if_data = kmem_alloc(real_size, KM_NOFS);
+		ifp->if_u1.if_data = kmem_zalloc(real_size, KM_NOFS);
 		memcpy(ifp->if_u1.if_data, data, size);
 		if (zero_terminate)
 			ifp->if_u1.if_data[size] = '\0';
@@ -498,10 +503,11 @@  xfs_idata_realloc(
 	/*
 	 * For inline data, the underlying buffer must be a multiple of 4 bytes
 	 * in size so that it can be logged and stay on word boundaries.
-	 * We enforce that here.
+	 * We enforce that here, and use __GFP_ZERO to ensure that size
+	 * extensions always zero the unused roundup area.
 	 */
 	ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
-				      GFP_NOFS | __GFP_NOFAIL);
+				      GFP_NOFS | __GFP_NOFAIL | __GFP_ZERO);
 	ifp->if_bytes = new_size;
 }