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. [dfeng@xxxxxxxxxx: Fix handling of multiple swap files] [a.p.zijlstra@xxxxxxxxx: Original patch] Signed-off-by: Mel Gorman <mgorman@xxxxxxx> --- fs/nfs/Kconfig | 8 ++++ fs/nfs/direct.c | 94 +++++++++++++++++++++++++++++-------------- 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 | 2 + net/sunrpc/sched.c | 7 +++- net/sunrpc/xprtsock.c | 53 ++++++++++++++++++++++++ 9 files changed, 161 insertions(+), 37 deletions(-) diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index 2a0e6c5..ff93d0c 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -75,6 +75,14 @@ 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_FS && NFS_V4 && EXPERIMENTAL diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 481be7f..2ef7395 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -111,17 +111,28 @@ 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_dirty_pages(struct page **pages, unsigned int pgbase, size_t count) @@ -278,7 +289,7 @@ static const struct rpc_call_ops nfs_read_direct_ops = { */ static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq, const struct iovec *iov, - loff_t pos) + loff_t pos, bool uio) { struct nfs_open_context *ctx = dreq->ctx; struct inode *inode = ctx->dentry->d_inode; @@ -312,13 +323,22 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq, if (unlikely(!data)) break; - down_read(¤t->mm->mmap_sem); - result = get_user_pages(current, current->mm, user_addr, - data->npages, 1, 0, data->pagevec, NULL); - up_read(¤t->mm->mmap_sem); - if (result < 0) { - nfs_readdata_free(data); - break; + if (uio) { + down_read(¤t->mm->mmap_sem); + result = get_user_pages(current, current->mm, user_addr, + data->npages, 1, 0, data->pagevec, NULL); + up_read(¤t->mm->mmap_sem); + if (result < 0) { + nfs_readdata_free(data); + break; + } + } else { + WARN_ON(data->npages != 1); + result = get_kernel_page(user_addr, 1, data->pagevec); + if (WARN_ON(result != 1)) { + nfs_readdata_free(data); + break; + } } if ((unsigned)result < data->npages) { bytes = result * PAGE_SIZE; @@ -386,7 +406,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq, 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) { ssize_t result = -EINVAL; size_t requested_bytes = 0; @@ -396,7 +416,7 @@ 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(dreq, vec, pos); + result = nfs_direct_read_schedule_segment(dreq, vec, pos, uio); if (result < 0) break; requested_bytes += result; @@ -420,7 +440,7 @@ 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; @@ -438,7 +458,7 @@ 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); out_release: @@ -705,7 +725,8 @@ static const struct rpc_call_ops nfs_write_direct_ops = { */ static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq, const struct iovec *iov, - loff_t pos, int sync) + loff_t pos, int sync, + bool uio) { struct nfs_open_context *ctx = dreq->ctx; struct inode *inode = ctx->dentry->d_inode; @@ -739,13 +760,22 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq, if (unlikely(!data)) break; - down_read(¤t->mm->mmap_sem); - result = get_user_pages(current, current->mm, user_addr, - data->npages, 0, 0, data->pagevec, NULL); - up_read(¤t->mm->mmap_sem); - if (result < 0) { - nfs_writedata_free(data); - break; + if (uio) { + down_read(¤t->mm->mmap_sem); + result = get_user_pages(current, current->mm, user_addr, + data->npages, 0, 0, data->pagevec, NULL); + up_read(¤t->mm->mmap_sem); + if (result < 0) { + nfs_writedata_free(data); + break; + } + } else { + WARN_ON(data->npages != 1); + result = get_kernel_page(user_addr, 0, data->pagevec); + if (WARN_ON(result != 1)) { + nfs_writedata_free(data); + break; + } } if ((unsigned)result < data->npages) { bytes = result * PAGE_SIZE; @@ -817,7 +847,8 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq, static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, const struct iovec *iov, unsigned long nr_segs, - loff_t pos, int sync) + loff_t pos, int sync, + bool uio) { ssize_t result = 0; size_t requested_bytes = 0; @@ -828,7 +859,7 @@ 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(dreq, vec, - pos, sync); + pos, sync, uio); if (result < 0) break; requested_bytes += result; @@ -853,7 +884,7 @@ 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; @@ -877,7 +908,8 @@ 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, sync); + result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, + sync, uio); if (!result) result = nfs_direct_wait(dreq); out_release: @@ -908,7 +940,7 @@ 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; @@ -933,7 +965,7 @@ 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; @@ -964,7 +996,7 @@ 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; @@ -996,7 +1028,7 @@ 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) iocb->ki_pos = pos + retval; diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 6ead5e3..0e330f2 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -187,7 +187,7 @@ 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, @@ -486,6 +486,20 @@ 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, @@ -500,6 +514,10 @@ 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 }; /* @@ -574,7 +592,7 @@ static 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 52a1bdb..1f4efab 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -481,10 +481,10 @@ 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 77d278d..cff40aa 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 9fe8857..03d03e3 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 adf2990..d6f4e623 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -719,6 +719,8 @@ 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 (task->tk_client->cl_xprt->swapper) + task->tk_flags |= RPC_TASK_SWAPPER; /* 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 994cfea..83a4c43 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 890b03f..b84df34 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1930,6 +1930,45 @@ 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); @@ -1954,6 +1993,8 @@ 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); @@ -1965,11 +2006,15 @@ static void xs_udp_setup_socket(struct work_struct *work) 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 status = -EIO; if (xprt->shutdown) goto out; + if (xprt->swapper) + current->flags |= PF_MEMALLOC; + /* Start by resetting any existing state */ xs_reset_transport(transport); sock = xs_create_sock(xprt, transport, @@ -1988,6 +2033,7 @@ static void xs_udp_setup_socket(struct work_struct *work) out: xprt_clear_connecting(xprt); xprt_wake_pending_tasks(xprt, status); + tsk_restore_flags(current, pflags, PF_MEMALLOC); } /* @@ -2078,6 +2124,8 @@ 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; @@ -2108,11 +2156,15 @@ static void xs_tcp_setup_socket(struct work_struct *work) container_of(work, struct sock_xprt, connect_worker.work); struct socket *sock = transport->sock; struct rpc_xprt *xprt = &transport->xprt; + unsigned long pflags = current->flags; int status = -EIO; if (xprt->shutdown) goto out; + if (xprt->swapper) + current->flags |= PF_MEMALLOC; + if (!sock) { clear_bit(XPRT_CONNECTION_ABORT, &xprt->state); sock = xs_create_sock(xprt, transport, @@ -2174,6 +2226,7 @@ out_eagain: out: xprt_clear_connecting(xprt); xprt_wake_pending_tasks(xprt, status); + tsk_restore_flags(current, pflags, PF_MEMALLOC); } /** -- 1.7.9.2 -- 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