[patch V2 14/29] dm bufio: Simplify stack trace retrieval

Thomas Gleixner
2019-04-18T08:41:33Z

Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Cc: Mike Snitzer <snitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Alasdair Kergon <agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
drivers/md/dm-bufio.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -150,7 +150,7 @@ struct dm_buffer {
void (*end_io)(struct dm_buffer *, blk_status_t);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
#define MAX_STACK 10
- struct stack_trace stack_trace;
+ unsigned int stack_len;
unsigned long stack_entries[MAX_STACK];
#endif
};
@@ -232,11 +232,7 @@ static DEFINE_MUTEX(dm_bufio_clients_loc
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
static void buffer_record_stack(struct dm_buffer *b)
{
- b->stack_trace.nr_entries = 0;
- b->stack_trace.max_entries = MAX_STACK;
- b->stack_trace.entries = b->stack_entries;
- b->stack_trace.skip = 2;
- save_stack_trace(&b->stack_trace);
+ b->stack_len = stack_trace_save(b->stack_entries, MAX_STACK, 2);
}
#endif

@@ -438,7 +434,7 @@ static struct dm_buffer *alloc_buffer(st
adjust_total_allocated(b->data_mode, (long)c->block_size);

#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
- memset(&b->stack_trace, 0, sizeof(b->stack_trace));
+ b->stack_len = 0;
#endif
return b;
}
@@ -1520,8 +1516,9 @@ static void drop_buffers(struct dm_bufio
DMERR("leaked buffer %llx, hold count %u, list %d",
(unsigned long long)b->block, b->hold_count, i);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
- print_stack_trace(&b->stack_trace, 1);
- b->hold_count = 0; /* mark unclaimed to avoid BUG_ON below */
+ stack_trace_print(b->stack_entries, b->stack_len, 1);
+ /* mark unclaimed to avoid BUG_ON below */
+ b->hold_count = 0;
#endif
}