From: Dan Magenheimer Subject: [PATCH V8 4/8] mm/fs: add hooks to support cleancache Date: Thu, 14 Apr 2011 14:17:32 -0700 Message-ID: <20110414211732.GA27761__21664.2285617583$1302815926$gmane$org@ca-server1.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: chris.mason@oracle.com, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, adilger.kernel@dilger.ca, tytso@mit.edu, mfasheh@suse.com, jlbec@evilplan.org, matthew@wil.cx, linux-btrfs@ Return-path: Received: from rcsinet10.oracle.com ([148.87.113.121]:22114 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753088Ab1DNVSV (ORCPT ); Thu, 14 Apr 2011 17:18:21 -0400 Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: [PATCH V8 4/8] mm/fs: add hooks to support cleancache This fourth patch of eight in this cleancache series provides the core hooks in VFS for: initializing cleancache per filesystem; capturing clean pages reclaimed by page cache; attempting to get pages from cleancache before filesystem read; and ensuring coherency between pagecache, disk, and cleancache. Note that the placement of these hooks was stable from 2.6.18 to 2.6.38; a minor semantic change was required due to a patchset in 2.6.39. All hooks become no-ops if CONFIG_CLEANCACHE is unset, or become a check of a boolean global if CONFIG_CLEANCACHE is set but no cleancache "backend" has claimed cleancache_ops. Details and a FAQ can be found in Documentation/vm/cleancache.txt [v8: minchan.kim@gmail.com: adapt to new remove_from_page_cache function] Signed-off-by: Chris Mason Signed-off-by: Dan Magenheimer Reviewed-by: Jeremy Fitzhardinge Reviewed-by: Konrad Rzeszutek Wilk Cc: Andrew Morton Cc: Al Viro Cc: Matthew Wilcox Cc: Nick Piggin Cc: Mel Gorman Cc: Rik Van Riel Cc: Jan Beulich Cc: Andreas Dilger Cc: Ted Ts'o Cc: Mark Fasheh Cc: Joel Becker Cc: Nitin Gupta --- Diffstat: fs/buffer.c | 5 +++++ fs/mpage.c | 7 +++++++ fs/super.c | 3 +++ mm/filemap.c | 11 +++++++++++ mm/truncate.c | 6 ++++++ 5 files changed, 32 insertions(+) --- linux-2.6.39-rc3/fs/super.c 2011-04-11 18:21:51.000000000 -0600 +++ linux-2.6.39-rc3-cleancache/fs/super.c 2011-04-13 17:08:09.175853426 -0600 @@ -31,6 +31,7 @@ #include #include #include +#include #include "internal.h" @@ -112,6 +113,7 @@ static struct super_block *alloc_super(s s->s_maxbytes = MAX_NON_LFS; s->s_op = &default_op; s->s_time_gran = 1000000000; + s->cleancache_poolid = -1; } out: return s; @@ -177,6 +179,7 @@ void deactivate_locked_super(struct supe { struct file_system_type *fs = s->s_type; if (atomic_dec_and_test(&s->s_active)) { + cleancache_flush_fs(s); fs->kill_sb(s); /* * We need to call rcu_barrier so all the delayed rcu free --- linux-2.6.39-rc3/fs/buffer.c 2011-04-11 18:21:51.000000000 -0600 +++ linux-2.6.39-rc3-cleancache/fs/buffer.c 2011-04-13 17:07:24.700917174 -0600 @@ -41,6 +41,7 @@ #include #include #include +#include static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); @@ -269,6 +270,10 @@ void invalidate_bdev(struct block_device invalidate_bh_lrus(); lru_add_drain_all(); /* make sure all lru add caches are flushed */ invalidate_mapping_pages(mapping, 0, -1); + /* 99% of the time, we don't need to flush the cleancache on the bdev. + * But, for the strange corners, lets be cautious + */ + cleancache_flush_inode(mapping); } EXPORT_SYMBOL(invalidate_bdev); --- linux-2.6.39-rc3/fs/mpage.c 2011-04-11 18:21:51.000000000 -0600 +++ linux-2.6.39-rc3-cleancache/fs/mpage.c 2011-04-13 17:07:24.706913410 -0600 @@ -27,6 +27,7 @@ #include #include #include +#include /* * I/O completion handler for multipage BIOs. @@ -271,6 +272,12 @@ do_mpage_readpage(struct bio *bio, struc SetPageMappedToDisk(page); } + if (fully_mapped && blocks_per_page == 1 && !PageUptodate(page) && + cleancache_get_page(page) == 0) { + SetPageUptodate(page); + goto confused; + } + /* * This page will go to BIO. Do we need to send this BIO off first? */ --- linux-2.6.39-rc3/mm/filemap.c 2011-04-11 18:21:51.000000000 -0600 +++ linux-2.6.39-rc3-cleancache/mm/filemap.c 2011-04-13 17:09:46.367852002 -0600 @@ -34,6 +34,7 @@ #include /* for BUG_ON(!in_atomic()) only */ #include #include /* for page_is_file_cache() */ +#include #include "internal.h" /* @@ -118,6 +119,16 @@ void __delete_from_page_cache(struct pag { struct address_space *mapping = page->mapping; + /* + * if we're uptodate, flush out into the cleancache, otherwise + * invalidate any existing cleancache entries. We can't leave + * stale data around in the cleancache once our page is gone + */ + if (PageUptodate(page) && PageMappedToDisk(page)) + cleancache_put_page(page); + else + cleancache_flush_page(mapping, page); + radix_tree_delete(&mapping->page_tree, page->index); page->mapping = NULL; mapping->nrpages--; --- linux-2.6.39-rc3/mm/truncate.c 2011-04-11 18:21:51.000000000 -0600 +++ linux-2.6.39-rc3-cleancache/mm/truncate.c 2011-04-13 17:07:24.710911759 -0600 @@ -19,6 +19,7 @@ #include #include /* grr. try_to_release_page, do_invalidatepage */ +#include #include "internal.h" @@ -51,6 +52,7 @@ void do_invalidatepage(struct page *page static inline void truncate_partial_page(struct page *page, unsigned partial) { zero_user_segment(page, partial, PAGE_CACHE_SIZE); + cleancache_flush_page(page->mapping, page); if (page_has_private(page)) do_invalidatepage(page, partial); } @@ -214,6 +216,7 @@ void truncate_inode_pages_range(struct a pgoff_t next; int i; + cleancache_flush_inode(mapping); if (mapping->nrpages == 0) return; @@ -291,6 +294,7 @@ void truncate_inode_pages_range(struct a pagevec_release(&pvec); mem_cgroup_uncharge_end(); } + cleancache_flush_inode(mapping); } EXPORT_SYMBOL(truncate_inode_pages_range); @@ -440,6 +444,7 @@ int invalidate_inode_pages2_range(struct int did_range_unmap = 0; int wrapped = 0; + cleancache_flush_inode(mapping); pagevec_init(&pvec, 0); next = start; while (next <= end && !wrapped && @@ -498,6 +503,7 @@ int invalidate_inode_pages2_range(struct mem_cgroup_uncharge_end(); cond_resched(); } + cleancache_flush_inode(mapping); return ret; } EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);