From: Jeremy Fitzhardinge Subject: Re: [PATCH V4 4/8] Cleancache: VFS hooks for cleancache Date: Mon, 30 Aug 2010 15:51:33 -0700 Message-ID: <4C7C35F5.6040508@goop.org> References: <20100830223203.GA1296@ca-server1.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: chris.mason@oracle.com, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, adilger@sun.com, tytso@mit.edu, mfasheh@suse.com, joel.becker@oracle.com, 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, ngupta@vflare.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 To: Dan Magenheimer Return-path: In-Reply-To: <20100830223203.GA1296@ca-server1.us.oracle.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On 08/30/2010 03:32 PM, Dan Magenheimer wrote: > [PATCH V4 4/8] Cleancache: VFS hooks for cleancache > > Implement core hooks in VFS for: initializing cleancache > per filesystem; capturing clean pages evicted by page cache; > attempting to get pages from cleancache before filesystem > read; and ensuring coherency between pagecache, disk, > and cleancache. All hooks become no-ops if CONFIG_CLEANCACHE > is unset, or become compare-function-pointer-to-NULL if > CONFIG_CLEANCACHE is set but no cleancache "backend" has > claimed cleancache_ops. > > Signed-off-by: Chris Mason > Signed-off-by: Dan Magenheimer > > Diffstat: > fs/buffer.c | 5 +++++ > fs/mpage.c | 7 +++++++ > fs/super.c | 7 +++++++ > mm/filemap.c | 11 +++++++++++ > mm/truncate.c | 10 ++++++++++ > 5 files changed, 40 insertions(+) > > --- linux-2.6.36-rc3/fs/super.c 2010-08-29 09:36:04.000000000 -0600 > +++ linux-2.6.36-rc3-cleancache/fs/super.c 2010-08-30 09:20:43.000000000 -0600 > @@ -30,6 +30,7 @@ > #include > #include > #include > +#include > #include "internal.h" > > > @@ -110,6 +111,7 @@ 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; > @@ -176,6 +178,11 @@ void deactivate_locked_super(struct supe > struct file_system_type *fs = s->s_type; > if (atomic_dec_and_test(&s->s_active)) { > fs->kill_sb(s); > + if (s->cleancache_poolid >= 0) { > + int cleancache_poolid = s->cleancache_poolid; That's a lot of characters for a local in a 3-line scope. > + s->cleancache_poolid = -1; /* avoid races */ Races with what? Something else sneaking something into the pool after the flush? Is the filesystem dead at this stage or not? > + cleancache_flush_fs(cleancache_poolid); > + } > put_filesystem(fs); > put_super(s); > } else { > --- linux-2.6.36-rc3/fs/buffer.c 2010-08-29 09:36:04.000000000 -0600 > +++ linux-2.6.36-rc3-cleancache/fs/buffer.c 2010-08-30 09:20:42.000000000 -0600 > @@ -41,6 +41,7 @@ > #include > #include > #include > +#include > > static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); > > @@ -277,6 +278,10 @@ 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 > + */ This comment-style is... unconventional for the kernel. > + cleancache_flush_inode(mapping); > } > EXPORT_SYMBOL(invalidate_bdev); > > --- linux-2.6.36-rc3/fs/mpage.c 2010-08-29 09:36:04.000000000 -0600 > +++ linux-2.6.36-rc3-cleancache/fs/mpage.c 2010-08-30 09:20:43.000000000 -0600 > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > > /* > * I/O completion handler for multipage BIOs. > @@ -286,6 +287,12 @@ 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-2.6.36-rc3/mm/filemap.c 2010-08-29 09:36:04.000000000 -0600 > +++ linux-2.6.36-rc3-cleancache/mm/filemap.c 2010-08-30 09:20:43.000000000 -0600 > @@ -34,6 +34,7 @@ > #include /* for BUG_ON(!in_atomic()) only */ > #include > #include /* for page_is_file_cache() */ > +#include > #include "internal.h" > > /* > @@ -119,6 +120,16 @@ void __remove_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)) > + cleancache_put_page(page); > + else > + cleancache_flush_page(mapping, page); > + > radix_tree_delete(&mapping->page_tree, page->index); > page->mapping = NULL; > mapping->nrpages--; > --- linux-2.6.36-rc3/mm/truncate.c 2010-08-29 09:36:04.000000000 -0600 > +++ linux-2.6.36-rc3-cleancache/mm/truncate.c 2010-08-30 09:20:43.000000000 -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); > } > @@ -108,6 +110,10 @@ truncate_complete_page(struct address_sp > clear_page_mlock(page); > remove_from_page_cache(page); > ClearPageMappedToDisk(page); > + /* this must be after the remove_from_page_cache which > + * calls cleancache_put_page (and note page->mapping is now NULL) > + */ > + cleancache_flush_page(mapping, page); > page_cache_release(page); /* pagecache ref */ > return 0; > } > @@ -215,6 +221,7 @@ void truncate_inode_pages_range(struct a > pgoff_t next; > int i; > > + cleancache_flush_inode(mapping); > if (mapping->nrpages == 0) > return; > > @@ -290,6 +297,7 @@ void truncate_inode_pages_range(struct a > pagevec_release(&pvec); > mem_cgroup_uncharge_end(); > } > + cleancache_flush_inode(mapping); > } > EXPORT_SYMBOL(truncate_inode_pages_range); > > @@ -428,6 +436,7 @@ 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 && > @@ -486,6 +495,7 @@ 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); > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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