| Message ID | 3d2f98b9ff9b10b65c273b828cb46c5dabbd865a.1491917365.git.bcodding@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2017-04-11 at 12:50 -0400, Benjamin Coddington wrote: > 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 | 34 +++++++++++++++++++++++++++++++++- > include/linux/nfs_fs.h | 1 + > include/linux/nfs_fs_sb.h | 1 + > include/linux/nfs_page.h | 1 + > 5 files changed, 37 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..3487d215cee1 100644 > --- a/fs/nfs/pagelist.c > +++ b/fs/nfs/pagelist.c > @@ -115,6 +115,35 @@ nfs_iocounter_wait(struct nfs_lock_context *l_ctx) > TASK_KILLABLE); > } > > +/** > + * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O > + * to complete > + * @task: the rpc_task that should wait > + * @l_ctx: nfs_lock_context with io_counter to check > + * > + * Returns true if there is outstanding I/O to wait on and the > + * task has been put to sleep. > + */ > +bool > +nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx) > +{ > + 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 +427,11 @@ 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..2a70f34dffe8 100644 > --- a/include/linux/nfs_fs_sb.h > +++ b/include/linux/nfs_fs_sb.h > @@ -222,6 +222,7 @@ struct nfs_server { > u32 mountd_version; > unsigned short mountd_port; > unsigned short mountd_protocol; > + struct rpc_wait_queue uoc_rpcwaitq; > }; > > /* Server capabilities */ > diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h > index 957049f72290..81105e473750 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 *, struct nfs_lock_context *); > > /* > * Lock the page of an asynchronous request Reviewed-by: Jeff Layton <jlayton@redhat.com>
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..3487d215cee1 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -115,6 +115,35 @@ nfs_iocounter_wait(struct nfs_lock_context *l_ctx) TASK_KILLABLE); } +/** + * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O + * to complete + * @task: the rpc_task that should wait + * @l_ctx: nfs_lock_context with io_counter to check + * + * Returns true if there is outstanding I/O to wait on and the + * task has been put to sleep. + */ +bool +nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx) +{ + 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 +427,11 @@ 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..2a70f34dffe8 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -222,6 +222,7 @@ struct nfs_server { u32 mountd_version; unsigned short mountd_port; unsigned short mountd_protocol; + struct rpc_wait_queue uoc_rpcwaitq; }; /* Server capabilities */ diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 957049f72290..81105e473750 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 *, struct nfs_lock_context *); /* * Lock the page of an asynchronous request
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 | 34 +++++++++++++++++++++++++++++++++- include/linux/nfs_fs.h | 1 + include/linux/nfs_fs_sb.h | 1 + include/linux/nfs_page.h | 1 + 5 files changed, 37 insertions(+), 1 deletion(-)