diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h index 19a69e7809d6..8eac4f3d5254 100644 --- a/include/linux/ref_tracker.h +++ b/include/linux/ref_tracker.h @@ -46,6 +46,8 @@ void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, void ref_tracker_dir_print(struct ref_tracker_dir *dir, unsigned int display_limit); +int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size); + int ref_tracker_alloc(struct ref_tracker_dir *dir, struct ref_tracker **trackerp, gfp_t gfp); @@ -74,6 +76,12 @@ static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir, { } +static inline int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, + char *buf, size_t size) +{ + return 0; +} + static inline int ref_tracker_alloc(struct ref_tracker_dir *dir, struct ref_tracker **trackerp, gfp_t gfp) diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c index 2ffe79c90c17..cce4614b0794 100644 --- a/lib/ref_tracker.c +++ b/lib/ref_tracker.c @@ -62,8 +62,27 @@ ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit) return stats; } -void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, - unsigned int display_limit) +struct ostream { + char *buf; + int size, used; +}; + +#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); \ + } \ +}) + +static void +__ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir, + unsigned int display_limit, struct ostream *s) { struct ref_tracker_dir_stats *stats; unsigned int i = 0, skipped; @@ -77,8 +96,8 @@ void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, stats = ref_tracker_get_stats(dir, display_limit); if (IS_ERR(stats)) { - pr_err("%s@%pK: couldn't get stats, error %pe\n", - dir->name, dir, stats); + pr_ostream(s, "%s@%pK: couldn't get stats, error %pe\n", + dir->name, dir, stats); return; } @@ -88,19 +107,27 @@ void ref_tracker_dir_print_locked(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_err("%s@%pK has %d/%d users at\n%s\n", dir->name, dir, - stats->stacks[i].count, stats->total, sbuf); + pr_ostream(s, "%s@%pK has %d/%d users at\n%s\n", dir->name, dir, + stats->stacks[i].count, stats->total, sbuf); skipped -= stats->stacks[i].count; } if (skipped) - pr_err("%s@%pK skipped reports about %d/%d users.\n", - dir->name, dir, skipped, stats->total); + pr_ostream(s, "%s@%pK skipped reports about %d/%d users.\n", + dir->name, dir, skipped, stats->total); kfree(sbuf); kfree(stats); } + +void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + struct ostream os = {}; + + __ref_tracker_dir_pr_ostream(dir, display_limit, &os); +} EXPORT_SYMBOL(ref_tracker_dir_print_locked); void ref_tracker_dir_print(struct ref_tracker_dir *dir, @@ -114,6 +141,19 @@ void ref_tracker_dir_print(struct ref_tracker_dir *dir, } 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 }; + unsigned long flags; + + spin_lock_irqsave(&dir->lock, flags); + __ref_tracker_dir_pr_ostream(dir, 16, &os); + spin_unlock_irqrestore(&dir->lock, flags); + + return os.used; +} +EXPORT_SYMBOL(ref_tracker_dir_snprint); + void ref_tracker_dir_exit(struct ref_tracker_dir *dir) { struct ref_tracker *tracker, *n;