[PATCH 3/4] treewide: convert PF_MEMALLOC manipulations to new helpers

Vlastimil Babka
2017-04-05T07:46:59Z

We now have memalloc_noreclaim_{save,restore} helpers for robust setting and
clearing of PF_MEMALLOC. Let's convert the code which was using the generic
tsk_restore_flags(). No functional change.

Signed-off-by: Vlastimil Babka <vbabka-AlSwsSmVLrQ@public.gmane.org>
Cc: Josef Bacik <jbacik-b10kYP2dOMg@public.gmane.org>
Cc: Lee Duncan <lduncan-IBi9RG/b67k@public.gmane.org>
Cc: Chris Leech <cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: Eric Dumazet <edumazet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
drivers/block/nbd.c | 7 ++++---
drivers/scsi/iscsi_tcp.c | 7 ++++---
net/core/dev.c | 7 ++++---
net/core/sock.c | 7 ++++---
4 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 03ae72985c79..929fc548c7fb 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/fs.h>
#include <linux/bio.h>
#include <linux/stat.h>
@@ -210,7 +211,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,
struct socket *sock = nbd->socks[index]->sock;
int result;
struct msghdr msg;
- unsigned long pflags = current->flags;
+ unsigned int noreclaim_flag;

if (unlikely(!sock)) {
dev_err_ratelimited(disk_to_dev(nbd->disk),
@@ -221,7 +222,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,

msg.msg_iter = *iter;

- current->flags |= PF_MEMALLOC;
+ noreclaim_flag = memalloc_noreclaim_save();
do {
sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
msg.msg_name = NULL;
@@ -244,7 +245,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,
*sent += result;
} while (msg_data_left(&msg));

- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ memalloc_noreclaim_restore(noreclaim_flag);

return result;
}
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 4228aba1f654..4842fc0e809d 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -30,6 +30,7 @@
#include <linux/types.h>
#include <linux/inet.h>
#include <linux/slab.h>
+#include <linux/sched/mm.h>
#include <linux/file.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
@@ -371,10 +372,10 @@ static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
- unsigned long pflags = current->flags;
+ unsigned int noreclaim_flag;
int rc = 0;

- current->flags |= PF_MEMALLOC;
+ noreclaim_flag = memalloc_noreclaim_save();

while (iscsi_sw_tcp_xmit_qlen(conn)) {
rc = iscsi_sw_tcp_xmit(conn);
@@ -387,7 +388,7 @@ static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
rc = 0;
}

- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ memalloc_noreclaim_restore(noreclaim_flag);
return rc;
}

diff --git a/net/core/dev.c b/net/core/dev.c
index fde8b3f7136b..e0705a126b24 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -81,6 +81,7 @@
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/mm.h>
@@ -4227,7 +4228,7 @@ static int __netif_receive_skb(struct sk_buff *skb)
int ret;

if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
- unsigned long pflags = current->flags;
+ unsigned int noreclaim_flag;

/*
* PFMEMALLOC skbs are special, they should
@@ -4238,9 +4239,9 @@ static int __netif_receive_skb(struct sk_buff *skb)
* Use PF_MEMALLOC as this saves us from propagating the allocation
* context down to all allocation sites.
*/
- current->flags |= PF_MEMALLOC;
+ noreclaim_flag = memalloc_noreclaim_save();
ret = __netif_receive_skb_core(skb, true);
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ memalloc_noreclaim_restore(noreclaim_flag);
} else
ret = __netif_receive_skb_core(skb, false);

diff --git a/net/core/sock.c b/net/core/sock.c
index 392f9b6f96e2..0b2d06b4c308 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -102,6 +102,7 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
@@ -372,14 +373,14 @@ EXPORT_SYMBOL_GPL(sk_clear_memalloc);
int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
int ret;
- unsigned long pflags = current->flags;
+ unsigned int noreclaim_flag;

/* these should have been dropped before queueing */
BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));

- current->flags |= PF_MEMALLOC;
+ noreclaim_flag = memalloc_noreclaim_save();
ret = sk->sk_backlog_rcv(sk, skb);
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ memalloc_noreclaim_restore(noreclaim_flag);

return ret;
}
--
2.12.2

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