From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org>
Checking the return code of every trace_seq_printf() operation and having
to return early if it overflowed makes the code messy.
Using the new trace_seq_has_overflowed() and trace_handle_return() functions
allows us to clean up the code.
In the future, trace_seq_printf() and friends will be turning into void
functions and not returning a value. The trace_seq_has_overflowed() is to
be used instead. This cleanup allows that change to take place.
Cc: Jens Axboe <ax...@fb.com>
Reviewed-by: Petr Mladek <pmla...@suse.cz>
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
kernel/trace/blktrace.c | 148 +++++++++++++++++++++---------------------------
1 file changed, 66 insertions(+), 82 deletions(-)
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c1bd4ada2a04..11b9cb36092b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1142,9 +1142,9 @@ static void get_pdu_remap(const struct trace_entry *ent,
r->sector_from = be64_to_cpu(sector_from);
}
-typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
+typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act);
-static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
+static void blk_log_action_classic(struct trace_iterator *iter, const char
*act)
{
char rwbs[RWBS_LEN];
unsigned long long ts = iter->ts;
@@ -1154,33 +1154,33 @@ static int blk_log_action_classic(struct trace_iterator
*iter, const char *act)
fill_rwbs(rwbs, t);
- return trace_seq_printf(&iter->seq,
- "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
- MAJOR(t->device), MINOR(t->device), iter->cpu,
- secs, nsec_rem, iter->ent->pid, act, rwbs);
+ trace_seq_printf(&iter->seq,
+ "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
+ MAJOR(t->device), MINOR(t->device), iter->cpu,
+ secs, nsec_rem, iter->ent->pid, act, rwbs);
}
-static int blk_log_action(struct trace_iterator *iter, const char *act)
+static void blk_log_action(struct trace_iterator *iter, const char *act)
{
char rwbs[RWBS_LEN];
const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
fill_rwbs(rwbs, t);
- return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
- MAJOR(t->device), MINOR(t->device), act, rwbs);
+ trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
+ MAJOR(t->device), MINOR(t->device), act, rwbs);
}
-static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry
*ent)
{
const unsigned char *pdu_buf;
int pdu_len;
- int i, end, ret;
+ int i, end;
pdu_buf = pdu_start(ent);
pdu_len = te_blk_io_trace(ent)->pdu_len;
if (!pdu_len)
- return 1;
+ return;
/* find the last zero that needs to be printed */
for (end = pdu_len - 1; end >= 0; end--)
@@ -1188,119 +1188,107 @@ static int blk_log_dump_pdu(struct trace_seq *s,
const struct trace_entry *ent)
break;
end++;
- if (!trace_seq_putc(s, '('))
- return 0;
+ trace_seq_putc(s, '(');
for (i = 0; i < pdu_len; i++) {
- ret = trace_seq_printf(s, "%s%02x",
- i == 0 ? "" : " ", pdu_buf[i]);
- if (!ret)
- return ret;
+ trace_seq_printf(s, "%s%02x",
+ i == 0 ? "" : " ", pdu_buf[i]);
/*
* stop when the rest is just zeroes and indicate so
* with a ".." appended
*/
- if (i == end && end != pdu_len - 1)
- return trace_seq_puts(s, " ..) ");
+ if (i == end && end != pdu_len - 1) {
+ trace_seq_puts(s, " ..) ");
+ return;
+ }
}
- return trace_seq_puts(s, ") ");
+ trace_seq_puts(s, ") ");
}
-static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
- int ret;
-
- ret = trace_seq_printf(s, "%u ", t_bytes(ent));
- if (!ret)
- return 0;
- ret = blk_log_dump_pdu(s, ent);
- if (!ret)
- return 0;
- return trace_seq_printf(s, "[%s]\n", cmd);
+ trace_seq_printf(s, "%u ", t_bytes(ent));
+ blk_log_dump_pdu(s, ent);
+ trace_seq_printf(s, "[%s]\n", cmd);
} else {
if (t_sec(ent))
- return trace_seq_printf(s, "%llu + %u [%s]\n",
+ trace_seq_printf(s, "%llu + %u [%s]\n",
t_sector(ent), t_sec(ent), cmd);
- return trace_seq_printf(s, "[%s]\n", cmd);
+ else
+ trace_seq_printf(s, "[%s]\n", cmd);
}
}
-static int blk_log_with_error(struct trace_seq *s,
+static void blk_log_with_error(struct trace_seq *s,
const struct trace_entry *ent)
{
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
- int ret;
-
- ret = blk_log_dump_pdu(s, ent);
- if (ret)
- return trace_seq_printf(s, "[%d]\n", t_error(ent));
- return 0;
+ blk_log_dump_pdu(s, ent);
+ trace_seq_printf(s, "[%d]\n", t_error(ent));
} else {
if (t_sec(ent))
- return trace_seq_printf(s, "%llu + %u [%d]\n",
- t_sector(ent),
- t_sec(ent), t_error(ent));
- return trace_seq_printf(s, "%llu [%d]\n",
- t_sector(ent), t_error(ent));
+ trace_seq_printf(s, "%llu + %u [%d]\n",
+ t_sector(ent),
+ t_sec(ent), t_error(ent));
+ else
+ trace_seq_printf(s, "%llu [%d]\n",
+ t_sector(ent), t_error(ent));
}
}
-static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
{
struct blk_io_trace_remap r = { .device_from = 0, };
get_pdu_remap(ent, &r);
- return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
- t_sector(ent), t_sec(ent),
- MAJOR(r.device_from), MINOR(r.device_from),
- (unsigned long long)r.sector_from);
+ trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
+ t_sector(ent), t_sec(ent),
+ MAJOR(r.device_from), MINOR(r.device_from),
+ (unsigned long long)r.sector_from);
}
-static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
- return trace_seq_printf(s, "[%s]\n", cmd);
+ trace_seq_printf(s, "[%s]\n", cmd);
}
-static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
- return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
+ trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
}
-static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
- return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
- get_pdu_int(ent), cmd);
+ trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
+ get_pdu_int(ent), cmd);
}
-static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
{
- int ret;
const struct blk_io_trace *t = te_blk_io_trace(ent);
- ret = trace_seq_putmem(s, t + 1, t->pdu_len);
- if (ret)
- return trace_seq_putc(s, '\n');
- return ret;
+ trace_seq_putmem(s, t + 1, t->pdu_len);
+ trace_seq_putc(s, '\n');
}
/*
@@ -1339,7 +1327,7 @@ static void blk_tracer_reset(struct trace_array *tr)
static const struct {
const char *act[2];
- int (*print)(struct trace_seq *s, const struct trace_entry *ent);
+ void (*print)(struct trace_seq *s, const struct trace_entry *ent);
} what2act[] = {
[__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
[__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
@@ -1364,7 +1352,6 @@ static enum print_line_t print_one_line(struct
trace_iterator *iter,
struct trace_seq *s = &iter->seq;
const struct blk_io_trace *t;
u16 what;
- int ret;
bool long_act;
blk_log_action_t *log_action;
@@ -1374,21 +1361,18 @@ static enum print_line_t print_one_line(struct
trace_iterator *iter,
log_action = classic ? &blk_log_action_classic : &blk_log_action;
if (t->action == BLK_TN_MESSAGE) {
- ret = log_action(iter, long_act ? "message" : "m");
- if (ret)
- ret = blk_log_msg(s, iter->ent);
- goto out;
+ log_action(iter, long_act ? "message" : "m");
+ blk_log_msg(s, iter->ent);
}
if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
- ret = trace_seq_printf(s, "Unknown action %x\n", what);
+ trace_seq_printf(s, "Unknown action %x\n", what);
else {
- ret = log_action(iter, what2act[what].act[long_act]);
- if (ret)
- ret = what2act[what].print(s, iter->ent);
+ log_action(iter, what2act[what].act[long_act]);
+ what2act[what].print(s, iter->ent);
}
-out:
- return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+
+ return trace_handle_return(s);
}
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
@@ -1397,7 +1381,7 @@ static enum print_line_t blk_trace_event_print(struct
trace_iterator *iter,
return print_one_line(iter, false);
}
-static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
+static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
@@ -1407,18 +1391,18 @@ static int blk_trace_synthesize_old_trace(struct
trace_iterator *iter)
.time = iter->ts,
};
- if (!trace_seq_putmem(s, &old, offset))
- return 0;
- return trace_seq_putmem(s, &t->sector,
- sizeof(old) - offset + t->pdu_len);
+ trace_seq_putmem(s, &old, offset);
+ trace_seq_putmem(s, &t->sector,
+ sizeof(old) - offset + t->pdu_len);
}
static enum print_line_t
blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
struct trace_event *event)
{
- return blk_trace_synthesize_old_trace(iter) ?
- TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+ blk_trace_synthesize_old_trace(iter);
+
+ return trace_handle_return(&iter->seq);
}
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
--
2.1.1
--
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