From d56b4ddf7781ef8dd050542781cc7f55673af002 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 31 Jul 2012 16:45:06 -0700 Subject: nfs: teach the NFS client how to treat PG_swapcache pages Replace all relevant occurences of page->index and page->mapping in the NFS client with the new page_file_index() and page_file_mapping() functions. Signed-off-by: Peter Zijlstra 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/file.c | 6 +++--- fs/nfs/internal.h | 7 ++++--- fs/nfs/pagelist.c | 2 +- fs/nfs/read.c | 6 +++--- fs/nfs/write.c | 36 ++++++++++++++++++------------------ 5 files changed, 29 insertions(+), 28 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 70d124a..acd4e4c 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -430,7 +430,7 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset) if (offset != 0) return; /* Cancel any unstarted writes on this page */ - nfs_wb_page_cancel(page->mapping->host, page); + nfs_wb_page_cancel(page_file_mapping(page)->host, page); nfs_fscache_invalidate_page(page, page->mapping->host); } @@ -472,7 +472,7 @@ static int nfs_release_page(struct page *page, gfp_t gfp) */ static int nfs_launder_page(struct page *page) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_inode *nfsi = NFS_I(inode); dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n", @@ -521,7 +521,7 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page); lock_page(page); - mapping = page->mapping; + mapping = page_file_mapping(page); if (mapping != dentry->d_inode->i_mapping) goto out_unlock; diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index cfafd13..4be14b3 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -546,13 +546,14 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize) static inline unsigned int nfs_page_length(struct page *page) { - loff_t i_size = i_size_read(page->mapping->host); + loff_t i_size = i_size_read(page_file_mapping(page)->host); if (i_size > 0) { + pgoff_t page_index = page_file_index(page); pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; - if (page->index < end_index) + if (page_index < end_index) return PAGE_CACHE_SIZE; - if (page->index == end_index) + if (page_index == end_index) return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1; } return 0; diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index aed913c..9ef8b3c 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -117,7 +117,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode, * long write-back delay. This will be adjusted in * update_nfs_request below if the region is not locked. */ req->wb_page = page; - req->wb_index = page->index; + req->wb_index = page_file_index(page); page_cache_get(page); req->wb_offset = offset; req->wb_pgbase = offset; diff --git a/fs/nfs/read.c b/fs/nfs/read.c index 6267b87..7cb0207 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -522,11 +522,11 @@ static const struct rpc_call_ops nfs_read_common_ops = { int nfs_readpage(struct file *file, struct page *page) { struct nfs_open_context *ctx; - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; int error; dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", - page, PAGE_CACHE_SIZE, page->index); + page, PAGE_CACHE_SIZE, page_file_index(page)); nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); nfs_add_stats(inode, NFSIOS_READPAGES, 1); @@ -580,7 +580,7 @@ static int readpage_async_filler(void *data, struct page *page) { struct nfs_readdesc *desc = (struct nfs_readdesc *)data; - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_page *new; unsigned int len; int error; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index f312860..d0feca3 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -153,7 +153,7 @@ static struct nfs_page *nfs_page_find_request_locked(struct page *page) static struct nfs_page *nfs_page_find_request(struct page *page) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req = NULL; spin_lock(&inode->i_lock); @@ -165,16 +165,16 @@ static struct nfs_page *nfs_page_find_request(struct page *page) /* Adjust the file length if we're writing beyond the end */ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; loff_t end, i_size; pgoff_t end_index; spin_lock(&inode->i_lock); i_size = i_size_read(inode); end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; - if (i_size > 0 && page->index < end_index) + if (i_size > 0 && page_file_index(page) < end_index) goto out; - end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count); + end = page_file_offset(page) + ((loff_t)offset+count); if (i_size >= end) goto out; i_size_write(inode, end); @@ -187,7 +187,7 @@ out: static void nfs_set_pageerror(struct page *page) { SetPageError(page); - nfs_zap_mapping(page->mapping->host, page->mapping); + nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page)); } /* We can set the PG_uptodate flag if we see that a write request @@ -228,7 +228,7 @@ static int nfs_set_page_writeback(struct page *page) int ret = test_set_page_writeback(page); if (!ret) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_server *nfss = NFS_SERVER(inode); if (atomic_long_inc_return(&nfss->writeback) > @@ -242,7 +242,7 @@ static int nfs_set_page_writeback(struct page *page) static void nfs_end_page_writeback(struct page *page) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_server *nfss = NFS_SERVER(inode); end_page_writeback(page); @@ -252,7 +252,7 @@ static void nfs_end_page_writeback(struct page *page) static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req; int ret; @@ -313,13 +313,13 @@ out: static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; int ret; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); - nfs_pageio_cond_complete(pgio, page->index); + nfs_pageio_cond_complete(pgio, page_file_index(page)); ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); if (ret == -EAGAIN) { redirty_page_for_writepage(wbc, page); @@ -336,7 +336,7 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc struct nfs_pageio_descriptor pgio; int err; - NFS_PROTO(page->mapping->host)->write_pageio_init(&pgio, + NFS_PROTO(page_file_mapping(page)->host)->write_pageio_init(&pgio, page->mapping->host, wb_priority(wbc), &nfs_async_write_completion_ops); @@ -471,7 +471,7 @@ nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, spin_unlock(cinfo->lock); if (!cinfo->dreq) { inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); - inc_bdi_stat(req->wb_page->mapping->backing_dev_info, + inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, BDI_RECLAIMABLE); __mark_inode_dirty(req->wb_context->dentry->d_inode, I_DIRTY_DATASYNC); @@ -538,7 +538,7 @@ static void nfs_clear_page_commit(struct page *page) { dec_zone_page_state(page, NR_UNSTABLE_NFS); - dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE); + dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE); } static void @@ -789,7 +789,7 @@ out_err: static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, struct page *page, unsigned int offset, unsigned int bytes) { - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req; req = nfs_try_to_update_request(inode, page, offset, bytes); @@ -842,7 +842,7 @@ int nfs_flush_incompatible(struct file *file, struct page *page) nfs_release_request(req); if (!do_flush) return 0; - status = nfs_wb_page(page->mapping->host, page); + status = nfs_wb_page(page_file_mapping(page)->host, page); } while (status == 0); return status; } @@ -872,7 +872,7 @@ int nfs_updatepage(struct file *file, struct page *page, unsigned int offset, unsigned int count) { struct nfs_open_context *ctx = nfs_file_open_context(file); - struct inode *inode = page->mapping->host; + struct inode *inode = page_file_mapping(page)->host; int status = 0; nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); @@ -880,7 +880,7 @@ int nfs_updatepage(struct file *file, struct page *page, dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n", file->f_path.dentry->d_parent->d_name.name, file->f_path.dentry->d_name.name, count, - (long long)(page_offset(page) + offset)); + (long long)(page_file_offset(page) + offset)); /* If we're not using byte range locks, and we know the page * is up to date, it may be more efficient to extend the write @@ -1469,7 +1469,7 @@ void nfs_retry_commit(struct list_head *page_list, nfs_mark_request_commit(req, lseg, cinfo); if (!cinfo->dreq) { dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); - dec_bdi_stat(req->wb_page->mapping->backing_dev_info, + dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info, BDI_RECLAIMABLE); } nfs_unlock_and_release_request(req); -- cgit v1.1 From 29418aa4bd487c82016733ef5c6a06d656ed3c7d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 31 Jul 2012 16:45:10 -0700 Subject: nfs: disable data cache revalidation for swapfiles The VM does not like PG_private set on PG_swapcache pages. As suggested by Trond in http://lkml.org/lkml/2006/8/25/348, this patch disables NFS data cache revalidation on swap files. as it does not make sense to have other clients change the file while it is being used as swap. This avoids setting PG_private on swap pages, since there ought to be no further races with invalidate_inode_pages2() to deal with. Since we cannot set PG_private we cannot use page->private which is already used by PG_swapcache pages to store the nfs_page. Thus augment the new nfs_page_find_request logic. Signed-off-by: Peter Zijlstra 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/inode.c | 4 ++++ fs/nfs/write.c | 49 +++++++++++++++++++++++++++++++++++-------------- 2 files changed, 39 insertions(+), 14 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 35f7e4b..1d57fe9 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -882,6 +882,10 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping) struct nfs_inode *nfsi = NFS_I(inode); int ret = 0; + /* swapfiles are not supposed to be shared. */ + if (IS_SWAPFILE(inode)) + goto out; + if (nfs_mapping_need_revalidate_inode(inode)) { ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode); if (ret < 0) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index d0feca3..974e9c2 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -139,15 +139,28 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); } -static struct nfs_page *nfs_page_find_request_locked(struct page *page) +static struct nfs_page * +nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) { struct nfs_page *req = NULL; - if (PagePrivate(page)) { + if (PagePrivate(page)) req = (struct nfs_page *)page_private(page); - if (req != NULL) - kref_get(&req->wb_kref); + else if (unlikely(PageSwapCache(page))) { + struct nfs_page *freq, *t; + + /* Linearly search the commit list for the correct req */ + list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) { + if (freq->wb_page == page) { + req = freq; + break; + } + } } + + if (req) + kref_get(&req->wb_kref); + return req; } @@ -157,7 +170,7 @@ static struct nfs_page *nfs_page_find_request(struct page *page) struct nfs_page *req = NULL; spin_lock(&inode->i_lock); - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); spin_unlock(&inode->i_lock); return req; } @@ -258,7 +271,7 @@ static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblo spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) break; if (nfs_lock_request(req)) @@ -413,9 +426,15 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) spin_lock(&inode->i_lock); if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) inode->i_version++; - set_bit(PG_MAPPED, &req->wb_flags); - SetPagePrivate(req->wb_page); - set_page_private(req->wb_page, (unsigned long)req); + /* + * Swap-space should not get truncated. Hence no need to plug the race + * with invalidate/truncate. + */ + if (likely(!PageSwapCache(req->wb_page))) { + set_bit(PG_MAPPED, &req->wb_flags); + SetPagePrivate(req->wb_page); + set_page_private(req->wb_page, (unsigned long)req); + } nfsi->npages++; kref_get(&req->wb_kref); spin_unlock(&inode->i_lock); @@ -432,9 +451,11 @@ static void nfs_inode_remove_request(struct nfs_page *req) BUG_ON (!NFS_WBACK_BUSY(req)); spin_lock(&inode->i_lock); - set_page_private(req->wb_page, 0); - ClearPagePrivate(req->wb_page); - clear_bit(PG_MAPPED, &req->wb_flags); + if (likely(!PageSwapCache(req->wb_page))) { + set_page_private(req->wb_page, 0); + ClearPagePrivate(req->wb_page); + clear_bit(PG_MAPPED, &req->wb_flags); + } nfsi->npages--; spin_unlock(&inode->i_lock); nfs_release_request(req); @@ -730,7 +751,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) goto out_unlock; @@ -1744,7 +1765,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page) */ int nfs_wb_page(struct inode *inode, struct page *page) { - loff_t range_start = page_offset(page); + loff_t range_start = page_file_offset(page); loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, -- cgit v1.1 From a564b8f0398636ba30b07c0eaebdef7ff7837249 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 31 Jul 2012 16:45:12 -0700 Subject: 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 ++++++++++++++-- 3 files changed, 82 insertions(+), 30 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index 404c6a8..6fd5f2c 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 42dce909..bf9c8d0 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 acd4e4c..50fb83a8 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, -- cgit v1.1 From 192e501b0438bb0e1574179773537f84c4752e25 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 31 Jul 2012 16:45:16 -0700 Subject: nfs: prevent page allocator recursions with swap over NFS. GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO, just not of any filesystem data. The problem is that previously NOFS was correct because that avoids recursion into the NFS code. With swap-over-NFS, it is no longer correct as swap IO can lead to this recursion. Signed-off-by: Peter Zijlstra 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/pagelist.c | 2 +- fs/nfs/write.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 9ef8b3c..7de1646 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -70,7 +70,7 @@ void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) static inline struct nfs_page * nfs_page_alloc(void) { - struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL); + struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO); if (p) INIT_LIST_HEAD(&p->wb_list); return p; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 974e9c2..211ba65 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -52,7 +52,7 @@ static mempool_t *nfs_commit_mempool; struct nfs_commit_data *nfs_commitdata_alloc(void) { - struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); + struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); if (p) { memset(p, 0, sizeof(*p)); @@ -70,7 +70,7 @@ EXPORT_SYMBOL_GPL(nfs_commit_free); struct nfs_write_header *nfs_writehdr_alloc(void) { - struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); + struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO); if (p) { struct nfs_pgio_header *hdr = &p->header; -- cgit v1.1