+ mm-mempool-do-not-allow-atomic-resizing.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm, mempool: do not allow atomic resizing
has been added to the -mm tree.  Its filename is
     mm-mempool-do-not-allow-atomic-resizing.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-mempool-do-not-allow-atomic-resizing.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempool-do-not-allow-atomic-resizing.patch

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------------------------------------------------------
From: David Rientjes <rientjes@google.com>
Subject: mm, mempool: do not allow atomic resizing

Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com>	[zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/s390/scsi/zfcp_erp.c |    4 ++--
 fs/cifs/connect.c            |    6 ++----
 include/linux/mempool.h      |    2 +-
 mm/mempool.c                 |    9 +++++----
 4 files changed, 10 insertions(+), 11 deletions(-)

diff -puN drivers/s390/scsi/zfcp_erp.c~mm-mempool-do-not-allow-atomic-resizing drivers/s390/scsi/zfcp_erp.c
--- a/drivers/s390/scsi/zfcp_erp.c~mm-mempool-do-not-allow-atomic-resizing
+++ a/drivers/s390/scsi/zfcp_erp.c
@@ -738,11 +738,11 @@ static int zfcp_erp_adapter_strategy_ope
 		return ZFCP_ERP_FAILED;
 
 	if (mempool_resize(act->adapter->pool.sr_data,
-			   act->adapter->stat_read_buf_num, GFP_KERNEL))
+			   act->adapter->stat_read_buf_num))
 		return ZFCP_ERP_FAILED;
 
 	if (mempool_resize(act->adapter->pool.status_read_req,
-			   act->adapter->stat_read_buf_num, GFP_KERNEL))
+			   act->adapter->stat_read_buf_num))
 		return ZFCP_ERP_FAILED;
 
 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
diff -puN fs/cifs/connect.c~mm-mempool-do-not-allow-atomic-resizing fs/cifs/connect.c
--- a/fs/cifs/connect.c~mm-mempool-do-not-allow-atomic-resizing
+++ a/fs/cifs/connect.c
@@ -773,8 +773,7 @@ static void clean_demultiplex_info(struc
 
 	length = atomic_dec_return(&tcpSesAllocCount);
 	if (length > 0)
-		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
-				GFP_KERNEL);
+		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 }
 
 static int
@@ -848,8 +847,7 @@ cifs_demultiplex_thread(void *p)
 
 	length = atomic_inc_return(&tcpSesAllocCount);
 	if (length > 1)
-		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
-				GFP_KERNEL);
+		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 
 	set_freezable();
 	while (server->tcpStatus != CifsExiting) {
diff -puN include/linux/mempool.h~mm-mempool-do-not-allow-atomic-resizing include/linux/mempool.h
--- a/include/linux/mempool.h~mm-mempool-do-not-allow-atomic-resizing
+++ a/include/linux/mempool.h
@@ -29,7 +29,7 @@ extern mempool_t *mempool_create_node(in
 			mempool_free_t *free_fn, void *pool_data,
 			gfp_t gfp_mask, int nid);
 
-extern int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask);
+extern int mempool_resize(mempool_t *pool, int new_min_nr);
 extern void mempool_destroy(mempool_t *pool);
 extern void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask);
 extern void mempool_free(void *element, mempool_t *pool);
diff -puN mm/mempool.c~mm-mempool-do-not-allow-atomic-resizing mm/mempool.c
--- a/mm/mempool.c~mm-mempool-do-not-allow-atomic-resizing
+++ a/mm/mempool.c
@@ -113,23 +113,24 @@ EXPORT_SYMBOL(mempool_create_node);
  *              mempool_create().
  * @new_min_nr: the new minimum number of elements guaranteed to be
  *              allocated for this pool.
- * @gfp_mask:   the usual allocation bitmask.
  *
  * This function shrinks/grows the pool. In the case of growing,
  * it cannot be guaranteed that the pool will be grown to the new
  * size immediately, but new mempool_free() calls will refill it.
+ * This function may sleep.
  *
  * Note, the caller must guarantee that no mempool_destroy is called
  * while this function is running. mempool_alloc() & mempool_free()
  * might be called (eg. from IRQ contexts) while this function executes.
  */
-int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
+int mempool_resize(mempool_t *pool, int new_min_nr)
 {
 	void *element;
 	void **new_elements;
 	unsigned long flags;
 
 	BUG_ON(new_min_nr <= 0);
+	might_sleep();
 
 	spin_lock_irqsave(&pool->lock, flags);
 	if (new_min_nr <= pool->min_nr) {
@@ -145,7 +146,7 @@ int mempool_resize(mempool_t *pool, int
 	spin_unlock_irqrestore(&pool->lock, flags);
 
 	/* Grow the pool */
-	new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
+	new_elements = kmalloc(new_min_nr * sizeof(*new_elements), GFP_KERNEL);
 	if (!new_elements)
 		return -ENOMEM;
 
@@ -164,7 +165,7 @@ int mempool_resize(mempool_t *pool, int
 
 	while (pool->curr_nr < pool->min_nr) {
 		spin_unlock_irqrestore(&pool->lock, flags);
-		element = pool->alloc(gfp_mask, pool->pool_data);
+		element = pool->alloc(GFP_KERNEL, pool->pool_data);
 		if (!element)
 			goto out;
 		spin_lock_irqsave(&pool->lock, flags);
_

Patches currently in -mm which might be from rientjes@google.com are

mm-hugetlb-close-race-when-setting-pagetail-for-gigantic-pages.patch
mm-fix-anon_vma-degree-underflow-in-anon_vma-endless-growing-prevention.patch
mm-fix-anon_vma-degree-underflow-in-anon_vma-endless-growing-prevention-v2.patch
mm-pagewalk-prevent-positive-return-value-of-walk_page_test-from-being-passed-to-callers.patch
cxgb4-drop-__gfp_nofail-allocation.patch
sh-dwarf-destroy-mempools-on-cleanup.patch
sh-dwarf-use-mempool_create_slab_pool.patch
jbd2-revert-must-not-fail-allocation-loops-back-to-gfp_nofail.patch
mm-slub-parse-slub_debug-o-option-in-switch-statement.patch
mm-rename-foll_mlock-to-foll_populate.patch
mm-rename-__mlock_vma_pages_range-to-populate_vma_page_range.patch
mm-move-gup-posix-mlock-error-conversion-out-of-__mm_populate.patch
mm-move-mm_populate-related-code-to-mm-gupc.patch
mm-hotplug-fix-concurrent-memory-hot-add-deadlock.patch
mm-cma-change-fallback-behaviour-for-cma-freepage.patch
mm-page_alloc-factor-out-fallback-freepage-checking.patch
mm-compaction-enhance-compaction-finish-condition.patch
mm-compaction-enhance-compaction-finish-condition-fix.patch
mm-incorporate-zero-pages-into-transparent-huge-pages.patch
mm-incorporate-zero-pages-into-transparent-huge-pages-fix.patch
mm-completely-remove-dumping-per-cpu-lists-from-show_mem.patch
mm-mempolicy-migrate_to_node-should-only-migrate-to-node.patch
mm-remove-gfp_thisnode.patch
mm-thp-really-limit-transparent-hugepage-allocation-to-local-node.patch
kernel-cpuset-remove-exception-for-__gfp_thisnode.patch
mm-clarify-__gfp_nofail-deprecation-status.patch
mm-clarify-__gfp_nofail-deprecation-status-checkpatch-fixes.patch
sparc-clarify-__gfp_nofail-allocation.patch
mm-mempool-do-not-allow-atomic-resizing.patch
mm-utilc-add-kstrimdup.patch