From mboxrd@z Thu Jan 1 00:00:00 1970 From: Minchan Kim Date: Fri, 15 Apr 2011 08:37:49 +0900 Subject: [Ocfs2-devel] [PATCH V8 4/8] mm/fs: add hooks to support cleancache In-Reply-To: <20110414211732.GA27761@ca-server1.us.oracle.com> References: <20110414211732.GA27761@ca-server1.us.oracle.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Magenheimer Cc: 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@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-mm@kvack.org, hch@infradead.org, ngupta@vflare.org, jeremy@goop.org, JBeulich@novell.com, kurt.hackel@oracle.com, npiggin@kernel.dk, dave.mccracken@oracle.com, riel@redhat.com, avi@redhat.com, konrad.wilk@oracle.com, mel@csn.ul.ie, yinghan@google.com, gthelen@google.com, torvalds@linux-foundation.org Hi Dan, On Fri, Apr 15, 2011 at 6:17 AM, Dan Magenheimer wrote: > [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 at 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); > + First of all, thanks for resolving conflict with my patch. Before I suggested a thing about cleancache_flush_page, cleancache_flush_inode. what's the meaning of flush's semantic? I thought it means invalidation. AFAIC, how about change flush with invalidate? -- Kind regards, Minchan Kim