From e2fecb215b321db0e4a5b2597349a63c07bec42f Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 6 Jan 2012 08:57:46 -0500 Subject: NFS: Remove pNFS bloat from the generic write path We have no business doing any this in the standard write release path. Get rid of it, and put it in the pNFS layer. Also, while we're at it, get rid of the completely bogus unlock/relock semantics that were present in nfs_writeback_release_full(). It is not only unnecessary, but actually dangerous to release the write lock just in order to take it again in nfs_page_async_flush(). Better just to open code the pgio operations in a pnfs helper. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 27 ++------------------------- 1 file changed, 2 insertions(+), 25 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 1dda78db6a73..0c3885255f97 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1052,7 +1052,7 @@ static const struct nfs_pageio_ops nfs_pageio_write_ops = { .pg_doio = nfs_generic_pg_writepages, }; -static void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio, +void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags) { nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, @@ -1166,13 +1166,7 @@ static void nfs_writeback_done_full(struct rpc_task *task, void *calldata) static void nfs_writeback_release_full(void *calldata) { struct nfs_write_data *data = calldata; - int ret, status = data->task.tk_status; - struct nfs_pageio_descriptor pgio; - - if (data->pnfs_error) { - nfs_pageio_init_write_mds(&pgio, data->inode, FLUSH_STABLE); - pgio.pg_recoalesce = 1; - } + int status = data->task.tk_status; /* Update attributes as result of writeback. */ while (!list_empty(&data->pages)) { @@ -1188,11 +1182,6 @@ static void nfs_writeback_release_full(void *calldata) req->wb_bytes, (long long)req_offset(req)); - if (data->pnfs_error) { - dprintk(", pnfs error = %d\n", data->pnfs_error); - goto next; - } - if (status < 0) { nfs_set_pageerror(page); nfs_context_set_write_error(req->wb_context, status); @@ -1212,19 +1201,7 @@ remove_request: next: nfs_clear_page_tag_locked(req); nfs_end_page_writeback(page); - if (data->pnfs_error) { - lock_page(page); - nfs_pageio_cond_complete(&pgio, page->index); - ret = nfs_page_async_flush(&pgio, page, 0); - if (ret) { - nfs_set_pageerror(page); - dprintk("rewrite to MDS error = %d\n", ret); - } - unlock_page(page); - } } - if (data->pnfs_error) - nfs_pageio_complete(&pgio); nfs_writedata_release(calldata); } -- cgit v1.2.3 From b969c4ab9f182a6e1b2a0848be349f99714947b0 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 12 Jan 2012 17:19:34 -0800 Subject: mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage Asynchronous compaction is used when allocating transparent hugepages to avoid blocking for long periods of time. Due to reports of stalling, there was a debate on disabling synchronous compaction but this severely impacted allocation success rates. Part of the reason was that many dirty pages are skipped in asynchronous compaction by the following check; if (PageDirty(page) && !sync && mapping->a_ops->migratepage != migrate_page) rc = -EBUSY; This skips over all mapping aops using buffer_migrate_page() even though it is possible to migrate some of these pages without blocking. This patch updates the ->migratepage callback with a "sync" parameter. It is the responsibility of the callback to fail gracefully if migration would block. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 0c3885255f97..889e98bc5a21 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1688,7 +1688,7 @@ out_error: #ifdef CONFIG_MIGRATION int nfs_migrate_page(struct address_space *mapping, struct page *newpage, - struct page *page) + struct page *page, bool sync) { /* * If PagePrivate is set, then the page is currently associated with @@ -1703,7 +1703,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage, nfs_fscache_release_page(page, GFP_KERNEL); - return migrate_page(mapping, newpage, page); + return migrate_page(mapping, newpage, page, sync); } #endif -- cgit v1.2.3 From a6bc32b899223a877f595ef9ddc1e89ead5072b8 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 12 Jan 2012 17:19:43 -0800 Subject: mm: compaction: introduce sync-light migration for use by compaction This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 889e98bc5a21..834f0fe96f89 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1688,7 +1688,7 @@ out_error: #ifdef CONFIG_MIGRATION int nfs_migrate_page(struct address_space *mapping, struct page *newpage, - struct page *page, bool sync) + struct page *page, enum migrate_mode mode) { /* * If PagePrivate is set, then the page is currently associated with @@ -1703,7 +1703,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage, nfs_fscache_release_page(page, GFP_KERNEL); - return migrate_page(mapping, newpage, page, sync); + return migrate_page(mapping, newpage, page, mode); } #endif -- cgit v1.2.3