[PATCH v4 2/2] nfs: make TASK_KILLABLE sleeps attempt to freeze

Jeff Layton
2011-11-29T12:37:16Z

Wrap the TASK_KILLABLE sleeps in NFS layer in freezer_do_not_count and
freezer_count calls. This allows the freezer to skip these processes
when they are sleeping while looping on EJUKEBOX or NFS4ERR_DELAY sorts
of errors.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
fs/nfs/inode.c | 3 ++-
fs/nfs/nfs3proc.c | 3 ++-
fs/nfs/nfs4proc.c | 5 +++--
fs/nfs/proc.c | 3 ++-
include/linux/freezer.h | 21 +++++++++++++++++++++
5 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 50a15fa..bf3a57b 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -38,6 +38,7 @@
#include <linux/nfs_xdr.h>
#include <linux/slab.h>
#include <linux/compat.h>
+#include <linux/freezer.h>

#include <asm/system.h>
#include <asm/uaccess.h>
@@ -77,7 +78,7 @@ int nfs_wait_bit_killable(void *word)
{
if (fatal_signal_pending(current))
return -ERESTARTSYS;
- schedule();
+ freezable_schedule();
return 0;
}

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index d4bc9ed9..9194395 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -17,6 +17,7 @@
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
#include <linux/nfs_mount.h>
+#include <linux/freezer.h>

#include "iostat.h"
#include "internal.h"
@@ -32,7 +33,7 @@ nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
res = rpc_call_sync(clnt, msg, flags);
if (res != -EJUKEBOX && res != -EKEYEXPIRED)
break;
- schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
+ freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
} while (!fatal_signal_pending(current));
return res;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index be2bbac..b28bb19 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -53,6 +53,7 @@
#include <linux/sunrpc/bc_xprt.h>
#include <linux/xattr.h>
#include <linux/utsname.h>
+#include <linux/freezer.h>

#include "nfs4_fs.h"
#include "delegation.h"
@@ -241,7 +242,7 @@ static int nfs4_delay(struct rpc_clnt *clnt, long *timeout)
*timeout = NFS4_POLL_RETRY_MIN;
if (*timeout > NFS4_POLL_RETRY_MAX)
*timeout = NFS4_POLL_RETRY_MAX;
- schedule_timeout_killable(*timeout);
+ freezable_schedule_timeout_killable(*timeout);
if (fatal_signal_pending(current))
res = -ERESTARTSYS;
*timeout <<= 1;
@@ -3950,7 +3951,7 @@ int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4
static unsigned long
nfs4_set_lock_task_retry(unsigned long timeout)
{
- schedule_timeout_killable(timeout);
+ freezable_schedule_timeout_killable(timeout);
timeout <<= 1;
if (timeout > NFS4_LOCK_MAXTIMEOUT)
return NFS4_LOCK_MAXTIMEOUT;
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index f48125d..0c672588 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -41,6 +41,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
+#include <linux/freezer.h>
#include "internal.h"

#define NFSDBG_FACILITY NFSDBG_PROC
@@ -59,7 +60,7 @@ nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
res = rpc_call_sync(clnt, msg, flags);
if (res != -EKEYEXPIRED)
break;
- schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
+ freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
} while (!fatal_signal_pending(current));
return res;
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index fda3ac6..29b5877 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -154,6 +154,24 @@ static inline void set_freezable_with_signal(void)
})

/*
+ * Like schedule_timeout_killable(), but should not block the freezer. It may
+ * end up returning immediately if it ends up racing with the freezer. Callers
+ * must be able to deal with the loose wakeup timing that can occur when the
+ * freezer races in. When that occurs, this function will return the timeout
+ * value instead of 0.
+ */
+#define freezable_schedule_timeout_killable(timeout) \
+({ \
+ freezer_do_not_count(); \
+ if (try_to_freeze()) { \
+ freezer_count(); \
+ return timeout; \
+ } \
+ schedule_timeout_killable(timeout); \
+ freezer_count(); \
+})
+
+/*
* Freezer-friendly wrappers around wait_event_interruptible(),
* wait_event_killable() and wait_event_interruptible_timeout(), originally
* defined in <linux/wait.h>
@@ -215,6 +233,9 @@ static inline void set_freezable_with_signal(void) {}

#define freezable_schedule() schedule()

+#define freezable_schedule_timeout_killable(timeout) \
+ schedule_timeout_killable(timeout)
+
#define wait_event_freezable(wq, condition) \
wait_event_interruptible(wq, condition)

--
1.7.6.4