block: Fix writeback throttling W=1 compiler warnings

[ Upstream commit 1d200e9d6f635ae894993a7d0f1b9e0b6e522e3b ]

Fix the following compiler warnings:

In file included from ./include/linux/bitmap.h:9,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/x86/include/asm/cpumask.h:5,
                 from ./arch/x86/include/asm/msr.h:11,
                 from ./arch/x86/include/asm/processor.h:21,
                 from ./arch/x86/include/asm/cpufeature.h:5,
                 from ./arch/x86/include/asm/thread_info.h:53,
                 from ./include/linux/thread_info.h:38,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/mmzone.h:8,
                 from ./include/linux/gfp.h:6,
                 from ./include/linux/mm.h:10,
                 from ./include/linux/bvec.h:13,
                 from ./include/linux/blk_types.h:10,
                 from block/blk-wbt.c:23:
In function 'strncpy',
    inlined from 'perf_trace_wbt_stat' at ./include/trace/events/wbt.h:15:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'perf_trace_wbt_lat' at ./include/trace/events/wbt.h:58:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'perf_trace_wbt_step' at ./include/trace/events/wbt.h:87:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'perf_trace_wbt_timer' at ./include/trace/events/wbt.h:126:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'trace_event_raw_event_wbt_stat' at ./include/trace/events/wbt.h:15:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'trace_event_raw_event_wbt_lat' at ./include/trace/events/wbt.h:58:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'trace_event_raw_event_wbt_timer' at ./include/trace/events/wbt.h:126:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'trace_event_raw_event_wbt_step' at ./include/trace/events/wbt.h:87:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: e34cbd307477 ("blk-wbt: add general throttling mechanism"; v4.10).
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/trace/events/wbt.h b/include/trace/events/wbt.h
index b048694070e2c20c8a02dc99bc0070e20e02ad02..37342a13c9cb9372f849f2e3d3d5c75bf7c7eb6b 100644 (file)
--- a/include/trace/events/wbt.h
+++ b/include/trace/events/wbt.h
@@ -33,7 +33,8 @@ TRACE_EVENT(wbt_stat,
        ),
 
        TP_fast_assign(
-               strncpy(__entry->name, dev_name(bdi->dev), 32);
+               strlcpy(__entry->name, dev_name(bdi->dev),
+                       ARRAY_SIZE(__entry->name));
                __entry->rmean          = stat[0].mean;
                __entry->rmin           = stat[0].min;
                __entry->rmax           = stat[0].max;
@@ -67,7 +68,8 @@ TRACE_EVENT(wbt_lat,
        ),
 
        TP_fast_assign(
-               strncpy(__entry->name, dev_name(bdi->dev), 32);
+               strlcpy(__entry->name, dev_name(bdi->dev),
+                       ARRAY_SIZE(__entry->name));
                __entry->lat = div_u64(lat, 1000);
        ),
 
@@ -103,7 +105,8 @@ TRACE_EVENT(wbt_step,
        ),
 
        TP_fast_assign(
-               strncpy(__entry->name, dev_name(bdi->dev), 32);
+               strlcpy(__entry->name, dev_name(bdi->dev),
+                       ARRAY_SIZE(__entry->name));
                __entry->msg    = msg;
                __entry->step   = step;
                __entry->window = div_u64(window, 1000);
@@ -138,7 +141,8 @@ TRACE_EVENT(wbt_timer,
        ),
 
        TP_fast_assign(
-               strncpy(__entry->name, dev_name(bdi->dev), 32);
+               strlcpy(__entry->name, dev_name(bdi->dev),
+                       ARRAY_SIZE(__entry->name));
                __entry->status         = status;
                __entry->step           = step;
                __entry->inflight       = inflight;