[dm-devel] [PATCH 1/4] libmpathpersist: limit PRIN allocation length to 8192 bytes

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

Some targets (notably the qemu-pr-helper) don't support PERSISTENT
RESERVE IN  commands with more than 8192 bytes allocation length.
While I have found no explicit requirement in the SCSI specs that
the allocation lengh may not exceed 8k, an 8k limit is also enforced
by sg_persist(8), and actually by mpathpersist itself for the
--allocation-length option, but not for the auto-determined length.

Fix that.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmpathpersist/mpath_pr_ioctl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libmpathpersist/mpath_pr_ioctl.c b/libmpathpersist/mpath_pr_ioctl.c
index 74b26b0c..1a28cba7 100644
--- a/libmpathpersist/mpath_pr_ioctl.c
+++ b/libmpathpersist/mpath_pr_ioctl.c
@@ -543,5 +543,7 @@ int get_prin_length(int rq_servact)
 			mx_resp_len = 0;
 			break;
 	}
+	if (mx_resp_len > MPATH_MAX_PARAM_LEN)
+		mx_resp_len = MPATH_MAX_PARAM_LEN;
 	return mx_resp_len;
 }
-- 
2.25.1