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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-13 12:12:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-13 12:12:44 -0700
commit3ad11d7ac8872b1c8da54494721fad8907ee41f7 (patch)
tree439d7cb75466978be936250c65a27ff05e82d9bc /lib
parent857d64485e7c920364688a8a6dd0ffe5774327b6 (diff)
parent8858e8d98d5457ba23bcd0d99ce23e272b8b09a1 (diff)
Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe: - Series of merge handling cleanups (Baolin, Christoph) - Series of blk-throttle fixes and cleanups (Baolin) - Series cleaning up BDI, seperating the block device from the backing_dev_info (Christoph) - Removal of bdget() as a generic API (Christoph) - Removal of blkdev_get() as a generic API (Christoph) - Cleanup of is-partition checks (Christoph) - Series reworking disk revalidation (Christoph) - Series cleaning up bio flags (Christoph) - bio crypt fixes (Eric) - IO stats inflight tweak (Gabriel) - blk-mq tags fixes (Hannes) - Buffer invalidation fixes (Jan) - Allow soft limits for zone append (Johannes) - Shared tag set improvements (John, Kashyap) - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel) - DM no-wait support (Mike, Konstantin) - Request allocation improvements (Ming) - Allow md/dm/bcache to use IO stat helpers (Song) - Series improving blk-iocost (Tejun) - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang, Xianting, Yang, Yufen, yangerkun) * tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits) block: fix uapi blkzoned.h comments blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue blk-mq: get rid of the dead flush handle code path block: get rid of unnecessary local variable block: fix comment and add lockdep assert blk-mq: use helper function to test hw stopped block: use helper function to test queue register block: remove redundant mq check block: invoke blk_mq_exit_sched no matter whether have .exit_sched percpu_ref: don't refer to ref->data if it isn't allocated block: ratelimit handle_bad_sector() message blk-throttle: Re-use the throtl_set_slice_end() blk-throttle: Open code __throtl_de/enqueue_tg() blk-throttle: Move service tree validation out of the throtl_rb_first() blk-throttle: Move the list operation after list validation blk-throttle: Fix IO hang for a corner case blk-throttle: Avoid tracking latency if low limit is invalid blk-throttle: Avoid getting the current time if tg->last_finish_time is 0 blk-throttle: Remove a meaningless parameter for throtl_downgrade_state() block: Remove redundant 'return' statement ...
Diffstat (limited to 'lib')
-rw-r--r--lib/percpu-refcount.c131
-rw-r--r--lib/vsprintf.c4
2 files changed, 100 insertions, 35 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 0ba686b8fe57..e59eda07305e 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -4,6 +4,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
+#include <linux/slab.h>
#include <linux/percpu-refcount.h>
/*
@@ -64,18 +65,25 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
size_t align = max_t(size_t, 1 << __PERCPU_REF_FLAG_BITS,
__alignof__(unsigned long));
unsigned long start_count = 0;
+ struct percpu_ref_data *data;
ref->percpu_count_ptr = (unsigned long)
__alloc_percpu_gfp(sizeof(unsigned long), align, gfp);
if (!ref->percpu_count_ptr)
return -ENOMEM;
- ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC;
- ref->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT;
+ data = kzalloc(sizeof(*ref->data), gfp);
+ if (!data) {
+ free_percpu((void __percpu *)ref->percpu_count_ptr);
+ return -ENOMEM;
+ }
+
+ data->force_atomic = flags & PERCPU_REF_INIT_ATOMIC;
+ data->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT;
if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) {
ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;
- ref->allow_reinit = true;
+ data->allow_reinit = true;
} else {
start_count += PERCPU_COUNT_BIAS;
}
@@ -85,14 +93,28 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
else
start_count++;
- atomic_long_set(&ref->count, start_count);
+ atomic_long_set(&data->count, start_count);
- ref->release = release;
- ref->confirm_switch = NULL;
+ data->release = release;
+ data->confirm_switch = NULL;
+ data->ref = ref;
+ ref->data = data;
return 0;
}
EXPORT_SYMBOL_GPL(percpu_ref_init);
+static void __percpu_ref_exit(struct percpu_ref *ref)
+{
+ unsigned long __percpu *percpu_count = percpu_count_ptr(ref);
+
+ if (percpu_count) {
+ /* non-NULL confirm_switch indicates switching in progress */
+ WARN_ON_ONCE(ref->data && ref->data->confirm_switch);
+ free_percpu(percpu_count);
+ ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;
+ }
+}
+
/**
* percpu_ref_exit - undo percpu_ref_init()
* @ref: percpu_ref to exit
@@ -105,27 +127,36 @@ EXPORT_SYMBOL_GPL(percpu_ref_init);
*/
void percpu_ref_exit(struct percpu_ref *ref)
{
- unsigned long __percpu *percpu_count = percpu_count_ptr(ref);
+ struct percpu_ref_data *data = ref->data;
+ unsigned long flags;
- if (percpu_count) {
- /* non-NULL confirm_switch indicates switching in progress */
- WARN_ON_ONCE(ref->confirm_switch);
- free_percpu(percpu_count);
- ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;
- }
+ __percpu_ref_exit(ref);
+
+ if (!data)
+ return;
+
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+ ref->percpu_count_ptr |= atomic_long_read(&ref->data->count) <<
+ __PERCPU_REF_FLAG_BITS;
+ ref->data = NULL;
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
+
+ kfree(data);
}
EXPORT_SYMBOL_GPL(percpu_ref_exit);
static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu)
{
- struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);
+ struct percpu_ref_data *data = container_of(rcu,
+ struct percpu_ref_data, rcu);
+ struct percpu_ref *ref = data->ref;
- ref->confirm_switch(ref);
- ref->confirm_switch = NULL;
+ data->confirm_switch(ref);
+ data->confirm_switch = NULL;
wake_up_all(&percpu_ref_switch_waitq);
- if (!ref->allow_reinit)
- percpu_ref_exit(ref);
+ if (!data->allow_reinit)
+ __percpu_ref_exit(ref);
/* drop ref from percpu_ref_switch_to_atomic() */
percpu_ref_put(ref);
@@ -133,7 +164,9 @@ static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu)
static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu)
{
- struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);
+ struct percpu_ref_data *data = container_of(rcu,
+ struct percpu_ref_data, rcu);
+ struct percpu_ref *ref = data->ref;
unsigned long __percpu *percpu_count = percpu_count_ptr(ref);
unsigned long count = 0;
int cpu;
@@ -142,7 +175,7 @@ static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu)
count += *per_cpu_ptr(percpu_count, cpu);
pr_debug("global %lu percpu %lu\n",
- atomic_long_read(&ref->count), count);
+ atomic_long_read(&data->count), count);
/*
* It's crucial that we sum the percpu counters _before_ adding the sum
@@ -156,11 +189,11 @@ static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu)
* reaching 0 before we add the percpu counts. But doing it at the same
* time is equivalent and saves us atomic operations:
*/
- atomic_long_add((long)count - PERCPU_COUNT_BIAS, &ref->count);
+ atomic_long_add((long)count - PERCPU_COUNT_BIAS, &data->count);
- WARN_ONCE(atomic_long_read(&ref->count) <= 0,
+ WARN_ONCE(atomic_long_read(&data->count) <= 0,
"percpu ref (%ps) <= 0 (%ld) after switching to atomic",
- ref->release, atomic_long_read(&ref->count));
+ data->release, atomic_long_read(&data->count));
/* @ref is viewed as dead on all CPUs, send out switch confirmation */
percpu_ref_call_confirm_rcu(rcu);
@@ -186,10 +219,11 @@ static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,
* Non-NULL ->confirm_switch is used to indicate that switching is
* in progress. Use noop one if unspecified.
*/
- ref->confirm_switch = confirm_switch ?: percpu_ref_noop_confirm_switch;
+ ref->data->confirm_switch = confirm_switch ?:
+ percpu_ref_noop_confirm_switch;
percpu_ref_get(ref); /* put after confirmation */
- call_rcu(&ref->rcu, percpu_ref_switch_to_atomic_rcu);
+ call_rcu(&ref->data->rcu, percpu_ref_switch_to_atomic_rcu);
}
static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
@@ -202,10 +236,10 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))
return;
- if (WARN_ON_ONCE(!ref->allow_reinit))
+ if (WARN_ON_ONCE(!ref->data->allow_reinit))
return;
- atomic_long_add(PERCPU_COUNT_BIAS, &ref->count);
+ atomic_long_add(PERCPU_COUNT_BIAS, &ref->data->count);
/*
* Restore per-cpu operation. smp_store_release() is paired
@@ -223,6 +257,8 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
static void __percpu_ref_switch_mode(struct percpu_ref *ref,
percpu_ref_func_t *confirm_switch)
{
+ struct percpu_ref_data *data = ref->data;
+
lockdep_assert_held(&percpu_ref_switch_lock);
/*
@@ -230,10 +266,10 @@ static void __percpu_ref_switch_mode(struct percpu_ref *ref,
* its completion. If the caller ensures that ATOMIC switching
* isn't in progress, this function can be called from any context.
*/
- wait_event_lock_irq(percpu_ref_switch_waitq, !ref->confirm_switch,
+ wait_event_lock_irq(percpu_ref_switch_waitq, !data->confirm_switch,
percpu_ref_switch_lock);
- if (ref->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))
+ if (data->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))
__percpu_ref_switch_to_atomic(ref, confirm_switch);
else
__percpu_ref_switch_to_percpu(ref);
@@ -266,7 +302,7 @@ void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
spin_lock_irqsave(&percpu_ref_switch_lock, flags);
- ref->force_atomic = true;
+ ref->data->force_atomic = true;
__percpu_ref_switch_mode(ref, confirm_switch);
spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
@@ -284,7 +320,7 @@ EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic);
void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref)
{
percpu_ref_switch_to_atomic(ref, NULL);
- wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);
+ wait_event(percpu_ref_switch_waitq, !ref->data->confirm_switch);
}
EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic_sync);
@@ -312,7 +348,7 @@ void percpu_ref_switch_to_percpu(struct percpu_ref *ref)
spin_lock_irqsave(&percpu_ref_switch_lock, flags);
- ref->force_atomic = false;
+ ref->data->force_atomic = false;
__percpu_ref_switch_mode(ref, NULL);
spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
@@ -344,7 +380,8 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
spin_lock_irqsave(&percpu_ref_switch_lock, flags);
WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,
- "%s called more than once on %ps!", __func__, ref->release);
+ "%s called more than once on %ps!", __func__,
+ ref->data->release);
ref->percpu_count_ptr |= __PERCPU_REF_DEAD;
__percpu_ref_switch_mode(ref, confirm_kill);
@@ -355,6 +392,34 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm);
/**
+ * percpu_ref_is_zero - test whether a percpu refcount reached zero
+ * @ref: percpu_ref to test
+ *
+ * Returns %true if @ref reached zero.
+ *
+ * This function is safe to call as long as @ref is between init and exit.
+ */
+bool percpu_ref_is_zero(struct percpu_ref *ref)
+{
+ unsigned long __percpu *percpu_count;
+ unsigned long count, flags;
+
+ if (__ref_is_percpu(ref, &percpu_count))
+ return false;
+
+ /* protect us from being destroyed */
+ spin_lock_irqsave(&percpu_ref_switch_lock, flags);
+ if (ref->data)
+ count = atomic_long_read(&ref->data->count);
+ else
+ count = ref->percpu_count_ptr >> __PERCPU_REF_FLAG_BITS;
+ spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
+
+ return count == 0;
+}
+EXPORT_SYMBOL_GPL(percpu_ref_is_zero);
+
+/**
* percpu_ref_reinit - re-initialize a percpu refcount
* @ref: perpcu_ref to re-initialize
*
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index afb9521ddf91..14c9a6af1b23 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -940,13 +940,13 @@ char *bdev_name(char *buf, char *end, struct block_device *bdev,
hd = bdev->bd_disk;
buf = string(buf, end, hd->disk_name, spec);
- if (bdev->bd_part->partno) {
+ if (bdev->bd_partno) {
if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
if (buf < end)
*buf = 'p';
buf++;
}
- buf = number(buf, end, bdev->bd_part->partno, spec);
+ buf = number(buf, end, bdev->bd_partno, spec);
}
return buf;
}