From a564b8f0398636ba30b07c0eaebdef7ff7837249 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 31 Jul 2012 16:45:12 -0700 Subject: [PATCH] nfs: enable swap on NFS Implement the new swapfile a_ops for NFS and hook up ->direct_IO. 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. [jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases] [dfeng@redhat.com: Fix handling of multiple swap files] [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman Acked-by: Rik van Riel Cc: Christoph Hellwig Cc: David S. Miller Cc: Eric B Munson Cc: Eric Paris Cc: James Morris Cc: Mel Gorman Cc: Mike Christie Cc: Neil Brown Cc: Sebastian Andrzej Siewior Cc: Trond Myklebust Cc: Xiaotian Feng Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/Kconfig | 8 ++++ fs/nfs/direct.c | 82 ++++++++++++++++++++++++------------- fs/nfs/file.c | 22 +++++++++- include/linux/nfs_fs.h | 4 +- include/linux/sunrpc/xprt.h | 3 ++ net/sunrpc/Kconfig | 5 +++ net/sunrpc/clnt.c | 9 ++++ net/sunrpc/sched.c | 7 +++- net/sunrpc/xprtsock.c | 43 +++++++++++++++++++ 9 files changed, 149 insertions(+), 34 deletions(-) diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index 404c6a8ac394..6fd5f2cdcd1e 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -86,6 +86,14 @@ config NFS_V4 If unsure, say Y. +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. + config NFS_V4_1 bool "NFS client support for NFSv4.1 (EXPERIMENTAL)" depends on NFS_V4 && EXPERIMENTAL diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 42dce909ec70..bf9c8d0ec16a 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -115,17 +115,28 @@ static inline int put_dreq(struct nfs_direct_req *dreq) * @nr_segs: size of iovec array * * The presence of this routine in the address space ops vector means - * the NFS client supports direct I/O. However, we shunt off direct - * read and write requests before the VFS gets them, so this method - * should never be called. + * the NFS client supports direct I/O. However, for most direct IO, we + * shunt off direct read and write requests before the VFS gets them, + * so this method is only ever called for swap. */ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) { +#ifndef CONFIG_NFS_SWAP dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", iocb->ki_filp->f_path.dentry->d_name.name, (long long) pos, nr_segs); return -EINVAL; +#else + VM_BUG_ON(iocb->ki_left != PAGE_SIZE); + VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE); + + if (rw == READ || rw == KERNEL_READ) + return nfs_file_direct_read(iocb, iov, nr_segs, pos, + rw == READ ? true : false); + return nfs_file_direct_write(iocb, iov, nr_segs, pos, + rw == WRITE ? true : false); +#endif /* CONFIG_NFS_SWAP */ } static void nfs_direct_release_pages(struct page **pages, unsigned int npages) @@ -303,7 +314,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { */ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc, const struct iovec *iov, - loff_t pos) + loff_t pos, bool uio) { struct nfs_direct_req *dreq = desc->pg_dreq; struct nfs_open_context *ctx = dreq->ctx; @@ -331,12 +342,20 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de GFP_KERNEL); if (!pagevec) break; - down_read(¤t->mm->mmap_sem); - result = get_user_pages(current, current->mm, user_addr, + if (uio) { + down_read(¤t->mm->mmap_sem); + result = get_user_pages(current, current->mm, user_addr, npages, 1, 0, pagevec, NULL); - up_read(¤t->mm->mmap_sem); - if (result < 0) - break; + up_read(¤t->mm->mmap_sem); + if (result < 0) + break; + } else { + WARN_ON(npages != 1); + result = get_kernel_page(user_addr, 1, pagevec); + if (WARN_ON(result != 1)) + break; + } + if ((unsigned)result < npages) { bytes = result * PAGE_SIZE; if (bytes <= pgbase) { @@ -386,7 +405,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, const struct iovec *iov, unsigned long nr_segs, - loff_t pos) + loff_t pos, bool uio) { struct nfs_pageio_descriptor desc; ssize_t result = -EINVAL; @@ -400,7 +419,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, for (seg = 0; seg < nr_segs; seg++) { const struct iovec *vec = &iov[seg]; - result = nfs_direct_read_schedule_segment(&desc, vec, pos); + result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio); if (result < 0) break; requested_bytes += result; @@ -426,7 +445,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, } static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) + unsigned long nr_segs, loff_t pos, bool uio) { ssize_t result = -ENOMEM; struct inode *inode = iocb->ki_filp->f_mapping->host; @@ -444,7 +463,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, if (!is_sync_kiocb(iocb)) dreq->iocb = iocb; - result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos); + result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio); if (!result) result = nfs_direct_wait(dreq); NFS_I(inode)->read_io += result; @@ -610,7 +629,7 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode */ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc, const struct iovec *iov, - loff_t pos) + loff_t pos, bool uio) { struct nfs_direct_req *dreq = desc->pg_dreq; struct nfs_open_context *ctx = dreq->ctx; @@ -638,12 +657,19 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d if (!pagevec) break; - down_read(¤t->mm->mmap_sem); - result = get_user_pages(current, current->mm, user_addr, - npages, 0, 0, pagevec, NULL); - up_read(¤t->mm->mmap_sem); - if (result < 0) - break; + if (uio) { + down_read(¤t->mm->mmap_sem); + result = get_user_pages(current, current->mm, user_addr, + npages, 0, 0, pagevec, NULL); + up_read(¤t->mm->mmap_sem); + if (result < 0) + break; + } else { + WARN_ON(npages != 1); + result = get_kernel_page(user_addr, 0, pagevec); + if (WARN_ON(result != 1)) + break; + } if ((unsigned)result < npages) { bytes = result * PAGE_SIZE; @@ -774,7 +800,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = { static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, const struct iovec *iov, unsigned long nr_segs, - loff_t pos) + loff_t pos, bool uio) { struct nfs_pageio_descriptor desc; struct inode *inode = dreq->inode; @@ -790,7 +816,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, for (seg = 0; seg < nr_segs; seg++) { const struct iovec *vec = &iov[seg]; - result = nfs_direct_write_schedule_segment(&desc, vec, pos); + result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio); if (result < 0) break; requested_bytes += result; @@ -818,7 +844,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos, - size_t count) + size_t count, bool uio) { ssize_t result = -ENOMEM; struct inode *inode = iocb->ki_filp->f_mapping->host; @@ -836,7 +862,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, if (!is_sync_kiocb(iocb)) dreq->iocb = iocb; - result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos); + result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio); if (!result) result = nfs_direct_wait(dreq); out_release: @@ -867,7 +893,7 @@ out: * cache. */ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) + unsigned long nr_segs, loff_t pos, bool uio) { ssize_t retval = -EINVAL; struct file *file = iocb->ki_filp; @@ -892,7 +918,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, task_io_account_read(count); - retval = nfs_direct_read(iocb, iov, nr_segs, pos); + retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio); if (retval > 0) iocb->ki_pos = pos + retval; @@ -923,7 +949,7 @@ out: * is no atomic O_APPEND write facility in the NFS protocol. */ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) + unsigned long nr_segs, loff_t pos, bool uio) { ssize_t retval = -EINVAL; struct file *file = iocb->ki_filp; @@ -955,7 +981,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, task_io_account_write(count); - retval = nfs_direct_write(iocb, iov, nr_segs, pos, count); + retval = nfs_direct_write(iocb, iov, nr_segs, pos, count, uio); if (retval > 0) { struct inode *inode = mapping->host; diff --git a/fs/nfs/file.c b/fs/nfs/file.c index acd4e4cd2906..50fb83a88b1b 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -175,7 +175,7 @@ nfs_file_read(struct kiocb *iocb, const struct iovec *iov, ssize_t result; if (iocb->ki_filp->f_flags & O_DIRECT) - return nfs_file_direct_read(iocb, iov, nr_segs, pos); + return nfs_file_direct_read(iocb, iov, nr_segs, pos, true); dprintk("NFS: read(%s/%s, %lu@%lu)\n", dentry->d_parent->d_name.name, dentry->d_name.name, @@ -482,6 +482,20 @@ static int nfs_launder_page(struct page *page) return nfs_wb_page(inode, page); } +#ifdef CONFIG_NFS_SWAP +static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, + sector_t *span) +{ + *span = sis->pages; + return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 1); +} + +static void nfs_swap_deactivate(struct file *file) +{ + 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, @@ -496,6 +510,10 @@ const struct address_space_operations nfs_file_aops = { .migratepage = nfs_migrate_page, .launder_page = nfs_launder_page, .error_remove_page = generic_error_remove_page, +#ifdef CONFIG_NFS_SWAP + .swap_activate = nfs_swap_activate, + .swap_deactivate = nfs_swap_deactivate, +#endif }; /* @@ -570,7 +588,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, size_t count = iov_length(iov, nr_segs); if (iocb->ki_filp->f_flags & O_DIRECT) - return nfs_file_direct_write(iocb, iov, nr_segs, pos); + return nfs_file_direct_write(iocb, iov, nr_segs, pos, true); dprintk("NFS: write(%s/%s, %lu@%Ld)\n", dentry->d_parent->d_name.name, dentry->d_name.name, diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 4b6043c20f77..35994f975a7f 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -473,10 +473,10 @@ extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t, unsigned long); extern ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, - loff_t pos); + loff_t pos, bool uio); extern ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, - loff_t pos); + loff_t pos, bool uio); /* * linux/fs/nfs/dir.c diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 77d278defa70..cff40aa7db62 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -174,6 +174,8 @@ struct rpc_xprt { unsigned long state; /* transport state */ unsigned char shutdown : 1, /* being shut down */ resvport : 1; /* use a reserved port */ + unsigned int swapper; /* we're swapping over this + transport */ unsigned int bind_index; /* bind function index */ /* @@ -316,6 +318,7 @@ void xprt_release_rqst_cong(struct rpc_task *task); 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 diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig index 9fe8857d8d59..03d03e37a7d5 100644 --- a/net/sunrpc/Kconfig +++ b/net/sunrpc/Kconfig @@ -21,6 +21,11 @@ config SUNRPC_XPRT_RDMA If unsure, say N. +config SUNRPC_SWAP + bool + depends on SUNRPC + select NETVM + config RPCSEC_GSS_KRB5 tristate "Secure RPC: Kerberos V mechanism" depends on SUNRPC && CRYPTO diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index b05df36692ff..fa48c60aef23 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -717,6 +717,15 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt) atomic_inc(&clnt->cl_count); if (clnt->cl_softrtry) task->tk_flags |= RPC_TASK_SOFT; + if (sk_memalloc_socks()) { + struct rpc_xprt *xprt; + + rcu_read_lock(); + xprt = rcu_dereference(clnt->cl_xprt); + if (xprt->swapper) + task->tk_flags |= RPC_TASK_SWAPPER; + rcu_read_unlock(); + } /* Add to the client's list of all tasks */ spin_lock(&clnt->cl_lock); list_add_tail(&task->tk_task, &clnt->cl_tasks); diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 994cfea2bad6..83a4c43cee7f 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -812,7 +812,10 @@ static void rpc_async_schedule(struct work_struct *work) 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) @@ -886,7 +889,7 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta 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); } /* diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 62d0dac8f780..bd59d01f035b 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1927,6 +1927,45 @@ out: xprt_wake_pending_tasks(xprt, status); } +#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); +} + +/** + * 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) { + xprt->swapper++; + xs_set_memalloc(xprt); + } else if (xprt->swapper) { + xprt->swapper--; + sk_clear_memalloc(transport->inet); + } + + 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); @@ -1951,6 +1990,8 @@ static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock) transport->sock = sock; transport->inet = sk; + xs_set_memalloc(xprt); + write_unlock_bh(&sk->sk_callback_lock); } xs_udp_do_set_buffer_size(xprt); @@ -2075,6 +2116,8 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock) if (!xprt_bound(xprt)) goto out; + xs_set_memalloc(xprt); + /* Tell the socket layer to start connecting... */ xprt->stat.connect_count++; xprt->stat.connect_start = jiffies; -- 2.20.1