[PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[zhong jiang]

The commit 391d4ee568b5 ("memfd: Fix locking when tagging pins")
introduces the following warning messages.

*WARNING: suspicious RCU usage in memfd_wait_for_pins*

It is because we still use radix_tree_deref_slot without read_rcu_lock.
We should use radix_tree_deref_slot_protected instead in the case.

Cc: stable@vger.kernel.org
Fixes: 391d4ee568b5 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 5b2cc9f9b1f1..e55aa460a2c0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2664,7 +2664,7 @@ static void shmem_tag_pins(struct address_space *mapping)
 
 	spin_lock_irq(&mapping->tree_lock);
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
-		page = radix_tree_deref_slot(slot);
+		page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
 		if (!page || radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
 				slot = radix_tree_iter_retry(&iter);
-- 
2.20.1

[PATCH 4.19] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[zhong jiang]

The commit 99b45e7a1ba1 ("memfd: Fix locking when tagging pins")
introduces the following warning messages.

*WARNING: suspicious RCU usage in memfd_wait_for_pins*

It is because we still use radix_tree_deref_slot without read_rcu_lock.
We should use radix_tree_deref_slot_protected instead in the case.

Cc: stable@vger.kernel.org
Fixes: 99b45e7a1ba1 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 mm/memfd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memfd.c b/mm/memfd.c
index 5859705dafe1..9e68a4320a0e 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -41,7 +41,7 @@ static void memfd_tag_pins(struct address_space *mapping)
 
 	xa_lock_irq(&mapping->i_pages);
 	radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
-		page = radix_tree_deref_slot(slot);
+		page = radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
 		if (!page || radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
 				slot = radix_tree_iter_retry(&iter);
-- 
2.20.1

[PATCH 4.4] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[zhong jiang]

The commit eb4058d8daf8 ("memfd: Fix locking when tagging pins")
introduces the following warning messages.

*WARNING: suspicious RCU usage in memfd_wait_for_pins*

It is because we still use radix_tree_deref_slot without read_rcu_lock.
We should use radix_tree_deref_slot_protected instead in the case.

Cc: stable@vger.kernel.org
Fixes: eb4058d8daf8 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 62668379623b..e40239bf6dfe 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1862,7 +1862,7 @@ static void shmem_tag_pins(struct address_space *mapping)
 	spin_lock_irq(&mapping->tree_lock);
 restart:
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
-		page = radix_tree_deref_slot(slot);
+		page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
 		if (!page || radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page))
 				goto restart;
-- 
2.20.1

[PATCH 4.9] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[zhong jiang]

The commit 3ce6b467b9b2 ("memfd: Fix locking when tagging pins")
introduces the following warning messages.

*WARNING: suspicious RCU usage in memfd_wait_for_pins*

It is because we still use radix_tree_deref_slot without read_rcu_lock.
We should use radix_tree_deref_slot_protected instead in the case.

Cc: stable@vger.kernel.org
Fixes: 3ce6b467b9b2 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index ac8a5fedc245..6266a7d1ba00 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2464,7 +2464,7 @@ static void shmem_tag_pins(struct address_space *mapping)
 
 	spin_lock_irq(&mapping->tree_lock);
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
-		page = radix_tree_deref_slot(slot);
+		page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
 		if (!page || radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
 				slot = radix_tree_iter_retry(&iter);
-- 
2.20.1

Re: [PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[Matthew Wilcox]

On Mon, Nov 18, 2019 at 11:26:07AM +0800, zhong jiang wrote:
> The commit 391d4ee568b5 ("memfd: Fix locking when tagging pins")
> introduces the following warning messages.
> 
> *WARNING: suspicious RCU usage in memfd_wait_for_pins*
> 
> It is because we still use radix_tree_deref_slot without read_rcu_lock.
> We should use radix_tree_deref_slot_protected instead in the case.
> 
> Cc: stable@vger.kernel.org
> Fixes: 391d4ee568b5 ("memfd: Fix locking when tagging pins")
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Re: [PATCH 4.19] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[Matthew Wilcox]

On Mon, Nov 18, 2019 at 11:26:08AM +0800, zhong jiang wrote:
> The commit 99b45e7a1ba1 ("memfd: Fix locking when tagging pins")
> introduces the following warning messages.
> 
> *WARNING: suspicious RCU usage in memfd_wait_for_pins*
> 
> It is because we still use radix_tree_deref_slot without read_rcu_lock.
> We should use radix_tree_deref_slot_protected instead in the case.
> 
> Cc: stable@vger.kernel.org
> Fixes: 99b45e7a1ba1 ("memfd: Fix locking when tagging pins")
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Re: [PATCH 4.4] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[Matthew Wilcox]

On Mon, Nov 18, 2019 at 11:26:09AM +0800, zhong jiang wrote:
> The commit eb4058d8daf8 ("memfd: Fix locking when tagging pins")
> introduces the following warning messages.
> 
> *WARNING: suspicious RCU usage in memfd_wait_for_pins*
> 
> It is because we still use radix_tree_deref_slot without read_rcu_lock.
> We should use radix_tree_deref_slot_protected instead in the case.
> 
> Cc: stable@vger.kernel.org
> Fixes: eb4058d8daf8 ("memfd: Fix locking when tagging pins")
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Re: [PATCH 4.9] memfd: Use radix_tree_deref_slot_protected to avoid the warning.

[Matthew Wilcox]

On Mon, Nov 18, 2019 at 11:26:10AM +0800, zhong jiang wrote:
> The commit 3ce6b467b9b2 ("memfd: Fix locking when tagging pins")
> introduces the following warning messages.
> 
> *WARNING: suspicious RCU usage in memfd_wait_for_pins*
> 
> It is because we still use radix_tree_deref_slot without read_rcu_lock.
> We should use radix_tree_deref_slot_protected instead in the case.
> 
> Cc: stable@vger.kernel.org
> Fixes: 3ce6b467b9b2 ("memfd: Fix locking when tagging pins")
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>