[Devel] [PATCH RHEL9 COMMIT] dm-ploop: make ploop_preallocate_cluster() return error on unexpected file size change

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-427.55.1.vz9.82.x-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh9-5.14.0-427.55.1.vz9.82.3
------>
commit 37be51378b4dcbe0c43ced0e069a132b4a498da9
Author: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
Date:   Mon Jul 7 15:07:02 2025 +0200

    dm-ploop: make ploop_preallocate_cluster() return error on unexpected file size change
    
    https://virtuozzo.atlassian.net/browse/VSTOR-108868
    Co-developed-by: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
    Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
    
    Feature: dm-ploop: ploop target driver
---
 drivers/md/dm-ploop-map.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index 0ddcb3d889b31..6c057ec92ee18 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -1194,12 +1194,16 @@ static int ploop_preallocate_cluster(struct ploop *ploop, struct file *file)
 		goto out;
 	}
 
-	/* here must be the only place to change file_size */
+	/*
+	 * Here must be the only place to change file_size.
+	 */
 	spin_lock_irqsave(&ploop->bat_lock, flags);
 	if (top->file_size < new_len) {
 		top->file_size = new_len;
 	} else {
 		PL_ERR("unexpected file size change\n");
+		ret = -EIO;
+		goto out;
 	}
 	if (ploop->prealloc_size)
 		goto prealloc_more;