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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.

[akpm@linux-foundation.org: coding-style fixes]
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Rientjes 2015-04-14 15:48:21 -07:00 committed by Linus Torvalds
parent 2415b9f5cb
commit 11d8336045
4 changed files with 11 additions and 11 deletions
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4
drivers/s390/scsi/zfcp_erp.c
View File

@ -738,11 +738,11 @@ static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
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);

6
fs/cifs/connect.c
View File

@ -773,8 +773,7 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
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) {

2
include/linux/mempool.h
View File

@ -29,7 +29,7 @@ extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
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);

10
mm/mempool.c
View File

@ -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 +146,8 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
spin_unlock_irqrestore(&pool->lock, flags);
/* Grow the pool */
new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
new_elements = kmalloc_array(new_min_nr, sizeof(*new_elements),
GFP_KERNEL);
if (!new_elements)
return -ENOMEM;
@ -164,7 +166,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
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);