From: Andriy Skulysh <c17819@cray.com>
Date: Wed, 6 Oct 2021 10:25:12 +0000 (+0300)
Subject: LU-15119 tgt: BUG at tgt_brw_read+0x16bf/0x1d80
X-Git-Tag: 2.14.56~37
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=283f7f247b938d13e3f88567dd71869d99146208;p=fs%2Flustre-release.git

LU-15119 tgt: BUG at tgt_brw_read+0x16bf/0x1d80

struct tgt_thread_big_cache {
  local = {{
      lnb_file_offset = 0,
      lnb_page_offset = 0,
      lnb_len = 0,
      lnb_rc = 0,
      lnb_page = 0xffffddee74fae100,
so npages_read becomes 0

Change-Id: Ie2201c9fc6f0350b1c6dcb480cff52f44d5413db
HPE-bug-id: LUS-10510
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Reviewed-on: https://review.whamcloud.com/45273
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/target/tgt_handler.c b/lustre/target/tgt_handler.c
index 3f3a3b5..5e97949 100644
--- a/lustre/target/tgt_handler.c
+++ b/lustre/target/tgt_handler.c
@@ -1948,6 +1948,9 @@ static int check_read_checksum(struct niobuf_local *local_nb, int npages,
 	enum cksum_types cksum_type;
 	loff_t start, end;
 
+	if (unlikely(npages <= 0))
+		return 0;
+
 	/* unlikely to happen and only if resend does not occur due to cksum
 	 * control failure on Client */
 	if (unlikely(server_cksum == client_cksum)) {