[4/6] NFS: Add an iocounter wait function for async RPC tasks
diff mbox

Message ID 0a6d92ce73dc1663f6700c3560df94685a63b125.1491015671.git.bcodding@redhat.com
State New
Headers show

Commit Message

Benjamin Coddington April 1, 2017, 3:16 a.m. UTC
By sleeping on a new NFS Unlock-On-Close waitqueue, rpc tasks may wait for
a lock context's iocounter to reach zero.  The rpc waitqueue is only woken
when the open_context has the NFS_CONTEXT_UNLOCK flag set in order to
mitigate spurious wake-ups for any iocounter reaching zero.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
 fs/nfs/client.c           |  1 +
 fs/nfs/pagelist.c         | 26 +++++++++++++++++++++++++-
 include/linux/nfs_fs.h    |  1 +
 include/linux/nfs_fs_sb.h |  1 +
 include/linux/nfs_page.h  |  1 +
 5 files changed, 29 insertions(+), 1 deletion(-)

Comments

kernel test robot April 2, 2017, 2:29 p.m. UTC | #1
Hi Benjamin,

[auto build test ERROR on nfs/linux-next]
[also build test ERROR on v4.11-rc4 next-20170331]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Benjamin-Coddington/Skipped-unlocks/20170402-195846
base:   git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next
config: cris-etrax-100lx_v2_defconfig (attached as .config)
compiler: cris-linux-gcc (GCC) 6.2.0
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=cris 

All errors (new ones prefixed by >>):

   fs/nfs/pagelist.c: In function 'nfs_async_iocounter_wait':
>> fs/nfs/pagelist.c:126:34: error: 'struct nfs_server' has no member named 'uoc_rpcwaitq'
      rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
                                     ^~
   fs/nfs/pagelist.c:131:45: error: 'struct nfs_server' has no member named 'uoc_rpcwaitq'
      rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
                                                ^~
   fs/nfs/pagelist.c: In function 'nfs_clear_request':
   fs/nfs/pagelist.c:425:50: error: 'struct nfs_server' has no member named 'uoc_rpcwaitq'
        rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
                                                     ^~

vim +126 fs/nfs/pagelist.c

   120	{
   121		struct nfs_lock_context *l_ctx = data;
   122		struct inode *inode = d_inode(l_ctx->open_context->dentry);
   123		bool ret = false;
   124	
   125		if (atomic_read(&l_ctx->io_count) > 0) {
 > 126			rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
   127			ret = true;
   128		}
   129	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Benjamin Coddington April 3, 2017, 9:42 a.m. UTC | #2
Ah, thanks robot.  I didn't notice the:

172 #if IS_ENABLED(CONFIG_NFS_V4)
173     u32         attr_bitmask[3];/* V4 bitmask representing the set
...
199     struct rpc_wait_queue   uoc_rpcwaitq;

I will re-post this one.

On 2 Apr 2017, at 10:29, kbuild test robot wrote:

> Hi Benjamin,
>
> [auto build test ERROR on nfs/linux-next]
> [also build test ERROR on v4.11-rc4 next-20170331]
> [if your patch is applied to the wrong git tree, please drop us a note 
> to help improve the system]
>
> url:    
> https://github.com/0day-ci/linux/commits/Benjamin-Coddington/Skipped-unlocks/20170402-195846
> base:   git://git.linux-nfs.org/projects/trondmy/linux-nfs.git 
> linux-next
> config: cris-etrax-100lx_v2_defconfig (attached as .config)
> compiler: cris-linux-gcc (GCC) 6.2.0
> reproduce:
>         wget 
> https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross 
> -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=cris
>
> All errors (new ones prefixed by >>):
>
>    fs/nfs/pagelist.c: In function 'nfs_async_iocounter_wait':
>>> fs/nfs/pagelist.c:126:34: error: 'struct nfs_server' has no member 
>>> named 'uoc_rpcwaitq'
>       rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
>                                      ^~
>    fs/nfs/pagelist.c:131:45: error: 'struct nfs_server' has no member 
> named 'uoc_rpcwaitq'
>       rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
>                                                 ^~
>    fs/nfs/pagelist.c: In function 'nfs_clear_request':
>    fs/nfs/pagelist.c:425:50: error: 'struct nfs_server' has no member 
> named 'uoc_rpcwaitq'
>         rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
>                                                      ^~
>
> vim +126 fs/nfs/pagelist.c
>
>    120	{
>    121		struct nfs_lock_context *l_ctx = data;
>    122		struct inode *inode = d_inode(l_ctx->open_context->dentry);
>    123		bool ret = false;
>    124	
>    125		if (atomic_read(&l_ctx->io_count) > 0) {
>> 126			rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
>    127			ret = true;
>    128		}
>    129	
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology 
> Center
> https://lists.01.org/pipermail/kbuild-all                   Intel 
> Corporation
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Patch
diff mbox

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 91a8d610ba0f..c335c6dce285 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -218,6 +218,7 @@  static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
 static void pnfs_init_server(struct nfs_server *server)
 {
 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
+	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
 }
 
 #else
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 6e629b856a00..d163819e4416 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -115,6 +115,27 @@  nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
 			TASK_KILLABLE);
 }
 
+bool
+nfs_async_iocounter_wait(struct rpc_task *task, void *data)
+{
+	struct nfs_lock_context *l_ctx = data;
+	struct inode *inode = d_inode(l_ctx->open_context->dentry);
+	bool ret = false;
+
+	if (atomic_read(&l_ctx->io_count) > 0) {
+		rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
+		ret = true;
+	}
+
+	if (atomic_read(&l_ctx->io_count) == 0) {
+		rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
+		ret = false;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
+
 /*
  * nfs_page_group_lock - lock the head of the page group
  * @req - request in group that is to be locked
@@ -398,8 +419,11 @@  static void nfs_clear_request(struct nfs_page *req)
 		req->wb_page = NULL;
 	}
 	if (l_ctx != NULL) {
-		if (atomic_dec_and_test(&l_ctx->io_count))
+		if (atomic_dec_and_test(&l_ctx->io_count)) {
 			wake_up_atomic_t(&l_ctx->io_count);
+			if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
+				rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
+		}
 		nfs_put_lock_context(l_ctx);
 		req->wb_lock_context = NULL;
 	}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index f1da8c8dd473..3ce3e42beead 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -76,6 +76,7 @@  struct nfs_open_context {
 #define NFS_CONTEXT_ERROR_WRITE		(0)
 #define NFS_CONTEXT_RESEND_WRITES	(1)
 #define NFS_CONTEXT_BAD			(2)
+#define NFS_CONTEXT_UNLOCK	(3)
 	int error;
 
 	struct list_head list;
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b34097c67848..a62cc2b0d30d 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -196,6 +196,7 @@  struct nfs_server {
 						   this filesystem */
 	struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
 	struct rpc_wait_queue	roc_rpcwaitq;
+	struct rpc_wait_queue	uoc_rpcwaitq;
 	void			*pnfs_ld_data;	/* per mount point data */
 
 	/* the following fields are protected by nfs_client->cl_lock */
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 957049f72290..d39ebcba52c8 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -141,6 +141,7 @@  extern int nfs_page_group_lock(struct nfs_page *, bool);
 extern void nfs_page_group_lock_wait(struct nfs_page *);
 extern void nfs_page_group_unlock(struct nfs_page *);
 extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
+extern bool nfs_async_iocounter_wait(struct rpc_task *, void *);
 
 /*
  * Lock the page of an asynchronous request