It is possible to call fsync on a read-only handle (for example, fsck.ext2
does it when doing read-only check), and this call results in kernel
warning. This bug was introduced by the commit 721c7fc701c7 "block: fail
op_is_write() requests to read-only partitions".
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Fixes: 721c7fc701c7 ("block: fail op_is_write() requests to read-only partitions")
Cc: stable@xxxxxxxxxxxxxxx # 4.18
---
block/blk-core.c | 3 +++
drivers/md/dm-verity-target.c | 33 +++++++++++++++++----------------
2 files changed, 20 insertions(+), 16 deletions(-)
Index: linux-2.6/block/blk-core.c
===================================================================
--- linux-2.6.orig/block/blk-core.c 2018-08-15 16:47:18.930000000 +0200
+++ linux-2.6/block/blk-core.c 2018-08-22 16:37:19.680000000 +0200
@@ -2155,6 +2155,9 @@ static inline bool bio_check_ro(struct b
if (part->policy && op_is_write(bio_op(bio))) {
char b[BDEVNAME_SIZE];
+ if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
+ return false;
+
WARN_ONCE(1,
"generic_make_request: Trying to write "
"to read-only block-device %s (partno %d)\n",
