From 567617a72703950def4737a4db91e42172a1c33c Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 25 Oct 2021 16:01:42 +0200
Subject: [PATCH] ocfs2: Fix data corruption on truncate
Patch-mainline: v5.16-rc1
Git-commit: 839b63860eb3835da165642923120d305925561d
References: bsc#1190795
ocfs2_truncate_file() did unmap invalidate page cache pages before
zeroing partial tail cluster and setting i_size. Thus some pages could
be left (and likely have left if the cluster zeroing happened) in the
page cache beyond i_size after truncate finished letting user possibly
see stale data once the file was extended again. Also the tail cluster
zeroing was not guaranteed to finish before truncate finished causing
possible stale data exposure. The problem started to be particularly
easy to hit after commit 6dbf7bb55598 "fs: Don't invalidate page buffers
in block_write_full_page()" stopped invalidation of pages beyond i_size
from page writeback path.
Fix these problems by unmapping and invalidating pages in the page cache
after the i_size is reduced and tail cluster is zeroed out.
CC: stable@vger.kernel.org
Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ocfs2/file.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 54d7843c0211..fc5f780fa235 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -476,10 +476,11 @@ int ocfs2_truncate_file(struct inode *inode,
* greater than page size, so we have to truncate them
* anyway.
*/
- unmap_mapping_range(inode->i_mapping, new_i_size + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(inode->i_mapping, new_i_size);
if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+ unmap_mapping_range(inode->i_mapping,
+ new_i_size + PAGE_SIZE - 1, 0, 1);
+ truncate_inode_pages(inode->i_mapping, new_i_size);
status = ocfs2_truncate_inline(inode, di_bh, new_i_size,
i_size_read(inode), 1);
if (status)
@@ -498,6 +499,9 @@ int ocfs2_truncate_file(struct inode *inode,
goto bail_unlock_sem;
}
+ unmap_mapping_range(inode->i_mapping, new_i_size + PAGE_SIZE - 1, 0, 1);
+ truncate_inode_pages(inode->i_mapping, new_i_size);
+
status = ocfs2_commit_truncate(osb, inode, di_bh);
if (status < 0) {
mlog_errno(status);
--
2.26.2