Commit 49c94af0 authored by Jeff Layton's avatar Jeff Layton Committed by Jakub Kicinski
Browse files

ref_tracker: have callers pass output function to pr_ostream() 



In a later patch, we'll be adding a 3rd mechanism for outputting
ref_tracker info via seq_file. Instead of a conditional, have the caller
set a pointer to an output function in struct ostream. As part of this,
the log prefix must be explicitly passed in, as it's too late for the
pr_fmt macro.

Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20250618-reftrack-dbgfs-v15-3-24fc37ead144@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e209f919

include/linux/ref_tracker.h

+2 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#include <linux/spinlock.h>

#include <linux/stackdepot.h>



#define __ostream_printf __printf(2, 3)



struct ref_tracker;



struct ref_tracker_dir {

lib/ref_tracker.c

+37 −15
Original line number Diff line number Diff line
@@ -63,21 +63,38 @@ ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit) 
}



struct ostream {

	void __ostream_printf (*func)(struct ostream *stream, char *fmt, ...);

	char *prefix;

	char *buf;

	int size, used;

};



static void __ostream_printf pr_ostream_log(struct ostream *stream, char *fmt, ...)

{

	va_list args;



	va_start(args, fmt);

	vprintk(fmt, args);

	va_end(args);

}



static void __ostream_printf pr_ostream_buf(struct ostream *stream, char *fmt, ...)

{

	int ret, len = stream->size - stream->used;

	va_list args;



	va_start(args, fmt);

	ret = vsnprintf(stream->buf + stream->used, len, fmt, args);

	va_end(args);

	if (ret > 0)

		stream->used += min(ret, len);

}



#define pr_ostream(stream, fmt, args...) \

({ \

	struct ostream *_s = (stream); \

\

	if (!_s->buf) { \

		pr_err(fmt, ##args); \

	} else { \

		int ret, len = _s->size - _s->used; \

		ret = snprintf(_s->buf + _s->used, len, pr_fmt(fmt), ##args); \

		_s->used += min(ret, len); \

	} \

	_s->func(_s, fmt, ##args); \

})



static void
@@ -96,8 +113,8 @@ __ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir, 


	stats = ref_tracker_get_stats(dir, display_limit);

	if (IS_ERR(stats)) {

		pr_ostream(s, "%s@%p: couldn't get stats, error %pe\n",

			   dir->name, dir, stats);

		pr_ostream(s, "%s%s@%p: couldn't get stats, error %pe\n",

			   s->prefix, dir->name, dir, stats);

		return;

	}
@@ -107,14 +124,15 @@ __ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir, 
		stack = stats->stacks[i].stack_handle;

		if (sbuf && !stack_depot_snprint(stack, sbuf, STACK_BUF_SIZE, 4))

			sbuf[0] = 0;

		pr_ostream(s, "%s@%p has %d/%d users at\n%s\n", dir->name, dir,

			   stats->stacks[i].count, stats->total, sbuf);

		pr_ostream(s, "%s%s@%p has %d/%d users at\n%s\n", s->prefix,

			   dir->name, dir, stats->stacks[i].count,

			   stats->total, sbuf);

		skipped -= stats->stacks[i].count;

	}



	if (skipped)

		pr_ostream(s, "%s@%p skipped reports about %d/%d users.\n",

			   dir->name, dir, skipped, stats->total);

		pr_ostream(s, "%s%s@%p skipped reports about %d/%d users.\n",

			   s->prefix, dir->name, dir, skipped, stats->total);



	kfree(sbuf);
@@ -124,7 +142,8 @@ __ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir, 
void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,

				  unsigned int display_limit)

{

	struct ostream os = {};

	struct ostream os = { .func = pr_ostream_log,

			      .prefix = "ref_tracker: " };



	__ref_tracker_dir_pr_ostream(dir, display_limit, &os);

}
@@ -143,7 +162,10 @@ EXPORT_SYMBOL(ref_tracker_dir_print); 


int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size)

{

	struct ostream os = { .buf = buf, .size = size };

	struct ostream os = { .func = pr_ostream_buf,

			      .prefix = "ref_tracker: ",

			      .buf = buf,

			      .size = size };

	unsigned long flags;



	spin_lock_irqsave(&dir->lock, flags);