[dm-devel] dm: impose configurable deadline for dm_request_fn's merge heuristic
Dan Carpenter
dan.carpenter at oracle.com
Mon Mar 2 16:31:44 UTC 2015
Hello Mike Snitzer,
The patch 6ee47d96b97d: "dm: impose configurable deadline for
dm_request_fn's merge heuristic" from Feb 26, 2015, leads to the
following static checker warning:
drivers/md/dm.c:1968 dm_attr_rq_based_queue_deadline_store()
warn: impossible condition '(deadline > ((~0 >> 1))) => (s32min-s32max > s32max)'
drivers/md/dm.c
1959 ssize_t dm_attr_rq_based_queue_deadline_store(struct mapped_device *md,
1960 const char *buf, size_t count)
1961 {
1962 int err, deadline;
1963
1964 if (!dm_request_based(md))
1965 return count;
1966
1967 err = kstrtoint(buf, 10, &deadline);
1968 if (err || deadline > INT_MAX)
^^^^^^^^^^^^^^^^^^
Impossible condition. But it might not hurt to test for negative
deadlines?
1969 return -EINVAL;
1970
1971 if (!deadline)
1972 deadline = DEF_QUEUE_DEADLINE;
1973 else if (deadline > MAX_QUEUE_DEADLINE)
1974 deadline = MAX_QUEUE_DEADLINE;
1975
1976 atomic_set(&md->rq_based_queue_deadline, deadline);
1977
1978 return count;
1979 }
regards,
dan carpenter
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