+++ /dev/null
-From: Peter Zijlstra <a.p.zijlstra@chello.nl>
-Subject: nfs: enable swap on NFS
-Patch-mainline: No
-References: FATE#303834
-
-Implement all the new swapfile a_ops for NFS. This will set the NFS socket to
-SOCK_MEMALLOC and run socket reconnect under PF_MEMALLOC as well as reset
-SOCK_MEMALLOC before engaging the protocol ->connect() method.
-
-PF_MEMALLOC should allow the allocation of struct socket and related objects
-and the early (re)setting of SOCK_MEMALLOC should allow us to receive the
-packets required for the TCP connection buildup.
-
-(swapping continues over a server reset during heavy network traffic)
-
-Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
-Acked-by: Neil Brown <neilb@suse.de>
-Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
-
----
- fs/Kconfig | 17 ++++++++++
- fs/nfs/file.c | 18 ++++++++++
- fs/nfs/write.c | 22 +++++++++++++
- include/linux/nfs_fs.h | 2 +
- include/linux/sunrpc/xprt.h | 5 ++-
- net/sunrpc/sched.c | 9 ++++-
- net/sunrpc/xprtsock.c | 73 ++++++++++++++++++++++++++++++++++++++++++++
- 7 files changed, 143 insertions(+), 3 deletions(-)
-
---- a/fs/Kconfig
-+++ b/fs/Kconfig
-@@ -1748,6 +1748,18 @@ config ROOT_NFS
-
- Most people say N here.
-
-+config NFS_SWAP
-+ bool "Provide swap over NFS support"
-+ default n
-+ depends on NFS_FS
-+ select SUNRPC_SWAP
-+ help
-+ This option enables swapon to work on files located on NFS mounts.
-+
-+ For more details, see Documentation/network-swap.txt
-+
-+ If unsure, say N.
-+
- config NFSD
- tristate "NFS server support"
- depends on INET
-@@ -1869,6 +1881,11 @@ config SUNRPC_XPRT_RDMA
-
- If unsure, say N.
-
-+config SUNRPC_SWAP
-+ def_bool n
-+ depends on SUNRPC
-+ select NETVM
-+
- config RPCSEC_GSS_KRB5
- tristate "Secure RPC: Kerberos V mechanism (EXPERIMENTAL)"
- depends on SUNRPC && EXPERIMENTAL
---- a/fs/nfs/file.c
-+++ b/fs/nfs/file.c
-@@ -434,6 +434,18 @@ static int nfs_launder_page(struct page
- return nfs_wb_page(inode, page);
- }
-
-+#ifdef CONFIG_NFS_SWAP
-+static int nfs_swapon(struct file *file)
-+{
-+ return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 1);
-+}
-+
-+static int nfs_swapoff(struct file *file)
-+{
-+ return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 0);
-+}
-+#endif
-+
- const struct address_space_operations nfs_file_aops = {
- .readpage = nfs_readpage,
- .readpages = nfs_readpages,
-@@ -446,6 +458,12 @@ const struct address_space_operations nf
- .releasepage = nfs_release_page,
- .direct_IO = nfs_direct_IO,
- .launder_page = nfs_launder_page,
-+#ifdef CONFIG_NFS_SWAP
-+ .swapon = nfs_swapon,
-+ .swapoff = nfs_swapoff,
-+ .swap_out = nfs_swap_out,
-+ .swap_in = nfs_readpage,
-+#endif
- };
-
- static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
---- a/fs/nfs/write.c
-+++ b/fs/nfs/write.c
-@@ -338,6 +338,28 @@ int nfs_writepage(struct page *page, str
- return ret;
- }
-
-+static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
-+ unsigned int offset, unsigned int count);
-+
-+int nfs_swap_out(struct file *file, struct page *page,
-+ struct writeback_control *wbc)
-+{
-+ struct nfs_open_context *ctx = nfs_file_open_context(file);
-+ int status;
-+
-+ status = nfs_writepage_setup(ctx, page, 0, nfs_page_length(page));
-+ if (status < 0) {
-+ nfs_set_pageerror(page);
-+ goto out;
-+ }
-+
-+ status = nfs_writepage_locked(page, wbc);
-+
-+out:
-+ unlock_page(page);
-+ return status;
-+}
-+
- static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
- {
- int ret;
---- a/include/linux/nfs_fs.h
-+++ b/include/linux/nfs_fs.h
-@@ -465,6 +465,8 @@ extern int nfs_flush_incompatible(struc
- extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
- extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
- extern void nfs_writedata_release(void *);
-+extern int nfs_swap_out(struct file *file, struct page *page,
-+ struct writeback_control *wbc);
-
- /*
- * Try to write back everything synchronously (but check the
---- a/include/linux/sunrpc/xprt.h
-+++ b/include/linux/sunrpc/xprt.h
-@@ -147,7 +147,9 @@ struct rpc_xprt {
- unsigned int max_reqs; /* total slots */
- unsigned long state; /* transport state */
- unsigned char shutdown : 1, /* being shut down */
-- resvport : 1; /* use a reserved port */
-+ resvport : 1, /* use a reserved port */
-+ swapper : 1; /* we're swapping over this
-+ transport */
- unsigned int bind_index; /* bind function index */
-
- /*
-@@ -249,6 +251,7 @@ void xprt_release_rqst_cong(struct rpc
- void xprt_disconnect_done(struct rpc_xprt *xprt);
- void xprt_force_disconnect(struct rpc_xprt *xprt);
- void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
-+int xs_swapper(struct rpc_xprt *xprt, int enable);
-
- /*
- * Reserved bit positions in xprt->state
---- a/net/sunrpc/sched.c
-+++ b/net/sunrpc/sched.c
-@@ -729,7 +729,10 @@ struct rpc_buffer {
- void *rpc_malloc(struct rpc_task *task, size_t size)
- {
- struct rpc_buffer *buf;
-- gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
-+ gfp_t gfp = GFP_NOWAIT;
-+
-+ if (RPC_IS_SWAPPER(task))
-+ gfp |= __GFP_MEMALLOC;
-
- size += sizeof(struct rpc_buffer);
- if (size <= RPC_BUFFER_MAXSIZE)
-@@ -800,6 +803,8 @@ static void rpc_init_task(struct rpc_tas
- kref_get(&task->tk_client->cl_kref);
- if (task->tk_client->cl_softrtry)
- task->tk_flags |= RPC_TASK_SOFT;
-+ if (task->tk_client->cl_xprt->swapper)
-+ task->tk_flags |= RPC_TASK_SWAPPER;
- }
-
- if (task->tk_ops->rpc_call_prepare != NULL)
-@@ -825,7 +830,7 @@ static void rpc_init_task(struct rpc_tas
- static struct rpc_task *
- rpc_alloc_task(void)
- {
-- return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
-+ return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOIO);
- }
-
- /*
---- a/net/sunrpc/xprtsock.c
-+++ b/net/sunrpc/xprtsock.c
-@@ -1453,6 +1453,55 @@ static inline void xs_reclassify_socket6
- }
- #endif
-
-+#ifdef CONFIG_SUNRPC_SWAP
-+static void xs_set_memalloc(struct rpc_xprt *xprt)
-+{
-+ struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
-+
-+ if (xprt->swapper)
-+ sk_set_memalloc(transport->inet);
-+}
-+
-+#define RPC_BUF_RESERVE_PAGES \
-+ kmalloc_estimate_objs(sizeof(struct rpc_rqst), GFP_KERNEL, RPC_MAX_SLOT_TABLE)
-+#define RPC_RESERVE_PAGES (RPC_BUF_RESERVE_PAGES + TX_RESERVE_PAGES)
-+
-+/**
-+ * xs_swapper - Tag this transport as being used for swap.
-+ * @xprt: transport to tag
-+ * @enable: enable/disable
-+ *
-+ */
-+int xs_swapper(struct rpc_xprt *xprt, int enable)
-+{
-+ struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
-+ int err = 0;
-+
-+ if (enable) {
-+ /*
-+ * keep one extra sock reference so the reserve won't dip
-+ * when the socket gets reconnected.
-+ */
-+ err = sk_adjust_memalloc(1, RPC_RESERVE_PAGES);
-+ if (!err) {
-+ xprt->swapper = 1;
-+ xs_set_memalloc(xprt);
-+ }
-+ } else if (xprt->swapper) {
-+ xprt->swapper = 0;
-+ sk_clear_memalloc(transport->inet);
-+ sk_adjust_memalloc(-1, -RPC_RESERVE_PAGES);
-+ }
-+
-+ return err;
-+}
-+EXPORT_SYMBOL_GPL(xs_swapper);
-+#else
-+static void xs_set_memalloc(struct rpc_xprt *xprt)
-+{
-+}
-+#endif
-+
- static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
- {
- struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
-@@ -1477,6 +1526,8 @@ static void xs_udp_finish_connecting(str
- transport->sock = sock;
- transport->inet = sk;
-
-+ xs_set_memalloc(xprt);
-+
- write_unlock_bh(&sk->sk_callback_lock);
- }
- xs_udp_do_set_buffer_size(xprt);
-@@ -1494,11 +1545,15 @@ static void xs_udp_connect_worker4(struc
- container_of(work, struct sock_xprt, connect_worker.work);
- struct rpc_xprt *xprt = &transport->xprt;
- struct socket *sock = transport->sock;
-+ unsigned long pflags = current->flags;
- int err, status = -EIO;
-
- if (xprt->shutdown || !xprt_bound(xprt))
- goto out;
-
-+ if (xprt->swapper)
-+ current->flags |= PF_MEMALLOC;
-+
- /* Start by resetting any existing state */
- xs_close(xprt);
-
-@@ -1521,6 +1576,7 @@ static void xs_udp_connect_worker4(struc
- out:
- xprt_wake_pending_tasks(xprt, status);
- xprt_clear_connecting(xprt);
-+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
- }
-
- /**
-@@ -1535,11 +1591,15 @@ static void xs_udp_connect_worker6(struc
- container_of(work, struct sock_xprt, connect_worker.work);
- struct rpc_xprt *xprt = &transport->xprt;
- struct socket *sock = transport->sock;
-+ unsigned long pflags = current->flags;
- int err, status = -EIO;
-
- if (xprt->shutdown || !xprt_bound(xprt))
- goto out;
-
-+ if (xprt->swapper)
-+ current->flags |= PF_MEMALLOC;
-+
- /* Start by resetting any existing state */
- xs_close(xprt);
-
-@@ -1562,6 +1622,7 @@ static void xs_udp_connect_worker6(struc
- out:
- xprt_wake_pending_tasks(xprt, status);
- xprt_clear_connecting(xprt);
-+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
- }
-
- /*
-@@ -1621,6 +1682,8 @@ static int xs_tcp_finish_connecting(stru
- write_unlock_bh(&sk->sk_callback_lock);
- }
-
-+ xs_set_memalloc(xprt);
-+
- /* Tell the socket layer to start connecting... */
- xprt->stat.connect_count++;
- xprt->stat.connect_start = jiffies;
-@@ -1639,11 +1702,15 @@ static void xs_tcp_connect_worker4(struc
- container_of(work, struct sock_xprt, connect_worker.work);
- struct rpc_xprt *xprt = &transport->xprt;
- struct socket *sock = transport->sock;
-+ unsigned long pflags = current->flags;
- int err, status = -EIO;
-
- if (xprt->shutdown || !xprt_bound(xprt))
- goto out;
-
-+ if (xprt->swapper)
-+ current->flags |= PF_MEMALLOC;
-+
- if (!sock) {
- /* start from scratch */
- if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
-@@ -1685,6 +1752,7 @@ out:
- xprt_wake_pending_tasks(xprt, status);
- out_clear:
- xprt_clear_connecting(xprt);
-+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
- }
-
- /**
-@@ -1699,11 +1767,15 @@ static void xs_tcp_connect_worker6(struc
- container_of(work, struct sock_xprt, connect_worker.work);
- struct rpc_xprt *xprt = &transport->xprt;
- struct socket *sock = transport->sock;
-+ unsigned long pflags = current->flags;
- int err, status = -EIO;
-
- if (xprt->shutdown || !xprt_bound(xprt))
- goto out;
-
-+ if (xprt->swapper)
-+ current->flags |= PF_MEMALLOC;
-+
- if (!sock) {
- /* start from scratch */
- if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
-@@ -1744,6 +1816,7 @@ out:
- xprt_wake_pending_tasks(xprt, status);
- out_clear:
- xprt_clear_connecting(xprt);
-+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
- }
-
- /**
projects / people / pmueller / ipfire-2.x.git / blobdiff