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Merge branch 'akpm' (patches from Andrew)

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Merge more fixes from Andrew Morton:
 "5 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  swap_readpage(): avoid blk_wake_io_task() if !synchronous
  devres: allow const resource arguments
  mm/vmscan.c: prevent useless kswapd loops
  fs/userfaultfd.c: disable irqs for fault_pending and event locks
  mm/page_alloc.c: fix regression with deferred struct page init
This commit is contained in:
Linus Torvalds 2019-07-05 11:39:56 +09:00
commit a5fff14a0c
6 changed files with 55 additions and 36 deletions
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42
fs/userfaultfd.c
View File

@ -40,6 +40,16 @@ enum userfaultfd_state {
/*
* Start with fault_pending_wqh and fault_wqh so they're more likely
* to be in the same cacheline.
*
* Locking order:
* fd_wqh.lock
* fault_pending_wqh.lock
* fault_wqh.lock
* event_wqh.lock
*
* To avoid deadlocks, IRQs must be disabled when taking any of the above locks,
* since fd_wqh.lock is taken by aio_poll() while it's holding a lock that's
* also taken in IRQ context.
*/
struct userfaultfd_ctx {
/* waitqueue head for the pending (i.e. not read) userfaults */
@ -458,7 +468,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
blocking_state = return_to_userland ? TASK_INTERRUPTIBLE :
TASK_KILLABLE;
spin_lock(&ctx->fault_pending_wqh.lock);
spin_lock_irq(&ctx->fault_pending_wqh.lock);
/*
* After the __add_wait_queue the uwq is visible to userland
* through poll/read().
@ -470,7 +480,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
* __add_wait_queue.
*/
set_current_state(blocking_state);
spin_unlock(&ctx->fault_pending_wqh.lock);
spin_unlock_irq(&ctx->fault_pending_wqh.lock);
if (!is_vm_hugetlb_page(vmf->vma))
must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags,
@ -552,13 +562,13 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
* kernel stack can be released after the list_del_init.
*/
if (!list_empty_careful(&uwq.wq.entry)) {
spin_lock(&ctx->fault_pending_wqh.lock);
spin_lock_irq(&ctx->fault_pending_wqh.lock);
/*
* No need of list_del_init(), the uwq on the stack
* will be freed shortly anyway.
*/
list_del(&uwq.wq.entry);
spin_unlock(&ctx->fault_pending_wqh.lock);
spin_unlock_irq(&ctx->fault_pending_wqh.lock);
}
/*
@ -583,7 +593,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
init_waitqueue_entry(&ewq->wq, current);
release_new_ctx = NULL;
spin_lock(&ctx->event_wqh.lock);
spin_lock_irq(&ctx->event_wqh.lock);
/*
* After the __add_wait_queue the uwq is visible to userland
* through poll/read().
@ -613,15 +623,15 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
break;
}
spin_unlock(&ctx->event_wqh.lock);
spin_unlock_irq(&ctx->event_wqh.lock);
wake_up_poll(&ctx->fd_wqh, EPOLLIN);
schedule();
spin_lock(&ctx->event_wqh.lock);
spin_lock_irq(&ctx->event_wqh.lock);
}
__set_current_state(TASK_RUNNING);
spin_unlock(&ctx->event_wqh.lock);
spin_unlock_irq(&ctx->event_wqh.lock);
if (release_new_ctx) {
struct vm_area_struct *vma;
@ -918,10 +928,10 @@ wakeup:
* the last page faults that may have been already waiting on
* the fault_*wqh.
*/
spin_lock(&ctx->fault_pending_wqh.lock);
spin_lock_irq(&ctx->fault_pending_wqh.lock);
__wake_up_locked_key(&ctx->fault_pending_wqh, TASK_NORMAL, &range);
__wake_up(&ctx->fault_wqh, TASK_NORMAL, 1, &range);
spin_unlock(&ctx->fault_pending_wqh.lock);
spin_unlock_irq(&ctx->fault_pending_wqh.lock);
/* Flush pending events that may still wait on event_wqh */
wake_up_all(&ctx->event_wqh);
@ -1134,7 +1144,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait,
if (!ret && msg->event == UFFD_EVENT_FORK) {
ret = resolve_userfault_fork(ctx, fork_nctx, msg);
spin_lock(&ctx->event_wqh.lock);
spin_lock_irq(&ctx->event_wqh.lock);
if (!list_empty(&fork_event)) {
/*
* The fork thread didn't abort, so we can
@ -1180,7 +1190,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait,
if (ret)
userfaultfd_ctx_put(fork_nctx);
}
spin_unlock(&ctx->event_wqh.lock);
spin_unlock_irq(&ctx->event_wqh.lock);
}
return ret;
@ -1219,14 +1229,14 @@ static ssize_t userfaultfd_read(struct file *file, char __user *buf,
static void __wake_userfault(struct userfaultfd_ctx *ctx,
struct userfaultfd_wake_range *range)
{
spin_lock(&ctx->fault_pending_wqh.lock);
spin_lock_irq(&ctx->fault_pending_wqh.lock);
/* wake all in the range and autoremove */
if (waitqueue_active(&ctx->fault_pending_wqh))
__wake_up_locked_key(&ctx->fault_pending_wqh, TASK_NORMAL,
range);
if (waitqueue_active(&ctx->fault_wqh))
__wake_up(&ctx->fault_wqh, TASK_NORMAL, 1, range);
spin_unlock(&ctx->fault_pending_wqh.lock);
spin_unlock_irq(&ctx->fault_pending_wqh.lock);
}
static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx,
@ -1881,7 +1891,7 @@ static void userfaultfd_show_fdinfo(struct seq_file *m, struct file *f)
wait_queue_entry_t *wq;
unsigned long pending = 0, total = 0;
spin_lock(&ctx->fault_pending_wqh.lock);
spin_lock_irq(&ctx->fault_pending_wqh.lock);
list_for_each_entry(wq, &ctx->fault_pending_wqh.head, entry) {
pending++;
total++;
@ -1889,7 +1899,7 @@ static void userfaultfd_show_fdinfo(struct seq_file *m, struct file *f)
list_for_each_entry(wq, &ctx->fault_wqh.head, entry) {
total++;
}
spin_unlock(&ctx->fault_pending_wqh.lock);
spin_unlock_irq(&ctx->fault_pending_wqh.lock);
/*
* If more protocols will be added, there will be all shown

3
include/linux/device.h
View File

@ -704,7 +704,8 @@ extern unsigned long devm_get_free_pages(struct device *dev,
gfp_t gfp_mask, unsigned int order);
extern void devm_free_pages(struct device *dev, unsigned long addr);
void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
void __iomem *devm_ioremap_resource(struct device *dev,
const struct resource *res);
void __iomem *devm_of_iomap(struct device *dev,
struct device_node *node, int index,

3
lib/devres.c
View File

@ -131,7 +131,8 @@ EXPORT_SYMBOL(devm_iounmap);
* if (IS_ERR(base))
* return PTR_ERR(base);
*/
void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
void __iomem *devm_ioremap_resource(struct device *dev,
const struct resource *res)
{
resource_size_t size;
void __iomem *dest_ptr;

3
mm/page_alloc.c
View File

@ -1826,7 +1826,8 @@ deferred_grow_zone(struct zone *zone, unsigned int order)
first_deferred_pfn)) {
pgdat->first_deferred_pfn = ULONG_MAX;
pgdat_resize_unlock(pgdat, &flags);
return true;
/* Retry only once. */
return first_deferred_pfn != ULONG_MAX;
}
/*

13
mm/page_io.c
View File

@ -137,8 +137,10 @@ out:
unlock_page(page);
WRITE_ONCE(bio->bi_private, NULL);
bio_put(bio);
blk_wake_io_task(waiter);
put_task_struct(waiter);
if (waiter) {
blk_wake_io_task(waiter);
put_task_struct(waiter);
}
}
int generic_swapfile_activate(struct swap_info_struct *sis,
@ -395,11 +397,12 @@ int swap_readpage(struct page *page, bool synchronous)
* Keep this task valid during swap readpage because the oom killer may
* attempt to access it in the page fault retry time check.
*/
get_task_struct(current);
bio->bi_private = current;
bio_set_op_attrs(bio, REQ_OP_READ, 0);
if (synchronous)
if (synchronous) {
bio->bi_opf |= REQ_HIPRI;
get_task_struct(current);
bio->bi_private = current;
}
count_vm_event(PSWPIN);
bio_get(bio);
qc = submit_bio(bio);

27
mm/vmscan.c
View File

@ -3644,19 +3644,18 @@ out:
}
/*
* pgdat->kswapd_classzone_idx is the highest zone index that a recent
* allocation request woke kswapd for. When kswapd has not woken recently,
* the value is MAX_NR_ZONES which is not a valid index. This compares a
* given classzone and returns it or the highest classzone index kswapd
* was recently woke for.
* The pgdat->kswapd_classzone_idx is used to pass the highest zone index to be
* reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is not
* a valid index then either kswapd runs for first time or kswapd couldn't sleep
* after previous reclaim attempt (node is still unbalanced). In that case
* return the zone index of the previous kswapd reclaim cycle.
*/
static enum zone_type kswapd_classzone_idx(pg_data_t *pgdat,
enum zone_type classzone_idx)
enum zone_type prev_classzone_idx)
{
if (pgdat->kswapd_classzone_idx == MAX_NR_ZONES)
return classzone_idx;
return max(pgdat->kswapd_classzone_idx, classzone_idx);
return prev_classzone_idx;
return pgdat->kswapd_classzone_idx;
}
static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_order,
@ -3797,7 +3796,7 @@ kswapd_try_sleep:
/* Read the new order and classzone_idx */
alloc_order = reclaim_order = pgdat->kswapd_order;
classzone_idx = kswapd_classzone_idx(pgdat, 0);
classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx);
pgdat->kswapd_order = 0;
pgdat->kswapd_classzone_idx = MAX_NR_ZONES;
@ -3851,8 +3850,12 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,
if (!cpuset_zone_allowed(zone, gfp_flags))
return;
pgdat = zone->zone_pgdat;
pgdat->kswapd_classzone_idx = kswapd_classzone_idx(pgdat,
classzone_idx);
if (pgdat->kswapd_classzone_idx == MAX_NR_ZONES)
pgdat->kswapd_classzone_idx = classzone_idx;
else
pgdat->kswapd_classzone_idx = max(pgdat->kswapd_classzone_idx,
classzone_idx);
pgdat->kswapd_order = max(pgdat->kswapd_order, order);
if (!waitqueue_active(&pgdat->kswapd_wait))
return;