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@xxxxxxxxxx>
---
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(-)
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
--
2.9.3
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
