[RFC for-next 1/3] block: reject unknown status tags in error injection rules

[Md Haris Iqbal <haris.iqbal@linux.dev>]

An unknown status tag leaves *status at BLK_STS_OK, which
error_inject_add() then rejects.  Fail in match_status() instead, so that
rejecting a bad tag does not rely on BLK_STS_OK being invalid for a rule.

For a single status= this does not change behaviour: an unknown tag still
fails the write with -EINVAL.  A repeated status= where an invalid tag
comes first is now rejected instead of being overridden by the later one.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Md Haris Iqbal <haris.iqbal@linux.dev>
---
 block/error-injection.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/block/error-injection.c b/block/error-injection.c
index e14bc4b723ef..47cdd8973adc 100644
--- a/block/error-injection.c
+++ b/block/error-injection.c
@@ -171,15 +171,18 @@ static int match_op(substring_t *args, enum req_op *op)
 static int match_status(substring_t *args, blk_status_t *status)
 {
 	const char *tag;
+	int ret = 0;
 
 	tag = match_strdup(args);
 	if (!tag)
 		return -ENOMEM;
 	*status = tag_to_blk_status(tag);
-	if (!*status)
+	if (!*status) {
 		pr_warn("invalid status '%s'\n", tag);
+		ret = -EINVAL;
+	}
 	kfree(tag);
-	return 0;
+	return ret;
 }
 
 static ssize_t blk_error_injection_parse_options(struct gendisk *disk,
-- 
2.53.0