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blk-cgroup: refactor blkcg_print_stat

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Factor out a helper to deal with a single blkcg_gq to make the code a
little bit easier to follow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210810152623.1796144-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
2021-08-10 17:26:22 +02:00
committed by Jens Axboe
parent 3973e15fa5
commit 49cb5168a7
1 changed files with 76 additions and 76 deletions
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54
block/blk-cgroup.c
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@@ -870,36 +870,23 @@ static void blkcg_fill_root_iostats(void)
} }
} }
static int blkcg_print_stat(struct seq_file *sf, void *v) static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)
{ {
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
struct blkcg_gq *blkg;
if (!seq_css(sf)->parent)
blkcg_fill_root_iostats();
else
cgroup_rstat_flush(blkcg->css.cgroup);
rcu_read_lock();
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
struct blkg_iostat_set *bis = &blkg->iostat; struct blkg_iostat_set *bis = &blkg->iostat;
const char *dname;
char *buf;
u64 rbytes, wbytes, rios, wios, dbytes, dios; u64 rbytes, wbytes, rios, wios, dbytes, dios;
size_t size = seq_get_buf(sf, &buf), off = 0;
int i;
bool has_stats = false; bool has_stats = false;
const char *dname;
unsigned seq; unsigned seq;
char *buf;
spin_lock_irq(&blkg->q->queue_lock); size_t size = seq_get_buf(s, &buf), off = 0;
int i;
if (!blkg->online) if (!blkg->online)
goto skip; return;
dname = blkg_dev_name(blkg); dname = blkg_dev_name(blkg);
if (!dname) if (!dname)
goto skip; return;
/* /*
* Hooray string manipulation, count is the size written NOT * Hooray string manipulation, count is the size written NOT
@@ -930,10 +917,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) { if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) {
has_stats = true; has_stats = true;
off += scnprintf(buf+off, size-off, off += scnprintf(buf+off, size-off, " use_delay=%d delay_nsec=%llu",
" use_delay=%d delay_nsec=%llu",
atomic_read(&blkg->use_delay), atomic_read(&blkg->use_delay),
(unsigned long long)atomic64_read(&blkg->delay_nsec)); atomic64_read(&blkg->delay_nsec));
} }
for (i = 0; i < BLKCG_MAX_POLS; i++) { for (i = 0; i < BLKCG_MAX_POLS; i++) {
@@ -952,15 +938,29 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
if (has_stats) { if (has_stats) {
if (off < size - 1) { if (off < size - 1) {
off += scnprintf(buf+off, size-off, "\n"); off += scnprintf(buf+off, size-off, "\n");
seq_commit(sf, off); seq_commit(s, off);
} else { } else {
seq_commit(sf, -1); seq_commit(s, -1);
} }
} }
skip:
spin_unlock_irq(&blkg->q->queue_lock);
} }
static int blkcg_print_stat(struct seq_file *sf, void *v)
{
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
struct blkcg_gq *blkg;
if (!seq_css(sf)->parent)
blkcg_fill_root_iostats();
else
cgroup_rstat_flush(blkcg->css.cgroup);
rcu_read_lock();
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
spin_lock_irq(&blkg->q->queue_lock);
blkcg_print_one_stat(blkg, sf);
spin_unlock_irq(&blkg->q->queue_lock);
}
rcu_read_unlock(); rcu_read_unlock();
return 0; return 0;
} }