Commit c515e1fd authored by Dan Magenheimer's avatar Dan Magenheimer
Browse files

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: default avatarChris Mason <chris.mason@oracle.com>
Signed-off-by: default avatarDan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: default avatarJeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
parent 077b1f83

fs/buffer.c

+5 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/bitops.h>

#include <linux/mpage.h>

#include <linux/bit_spinlock.h>

#include <linux/cleancache.h>



static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
@@ -269,6 +270,10 @@ void invalidate_bdev(struct block_device *bdev) 
	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);

fs/mpage.c

+7 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/writeback.h>

#include <linux/backing-dev.h>

#include <linux/pagevec.h>

#include <linux/cleancache.h>



/*

 * I/O completion handler for multipage BIOs.
@@ -271,6 +272,12 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, 
		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?

	 */

fs/super.c

+3 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/mutex.h>

#include <linux/backing-dev.h>

#include <linux/rculist_bl.h>

#include <linux/cleancache.h>

#include "internal.h"
@@ -112,6 +113,7 @@ static struct super_block *alloc_super(struct file_system_type *type) 
		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 super_block *s) 
{

	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

mm/filemap.c

+11 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */

#include <linux/memcontrol.h>

#include <linux/mm_inline.h> /* for page_is_file_cache() */

#include <linux/cleancache.h>

#include "internal.h"



/*
@@ -118,6 +119,16 @@ void __delete_from_page_cache(struct page *page) 
{

	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--;

mm/truncate.c

+6 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/task_io_accounting_ops.h>

#include <linux/buffer_head.h>	/* grr. try_to_release_page,

				   do_invalidatepage */

#include <linux/cleancache.h>

#include "internal.h"
@@ -51,6 +52,7 @@ void do_invalidatepage(struct page *page, unsigned long offset) 
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 address_space *mapping, 
	pgoff_t next;

	int i;



	cleancache_flush_inode(mapping);

	if (mapping->nrpages == 0)

		return;
@@ -291,6 +294,7 @@ void truncate_inode_pages_range(struct address_space *mapping, 
		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 address_space *mapping, 
	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 address_space *mapping, 
		mem_cgroup_uncharge_end();

		cond_resched();

	}

	cleancache_flush_inode(mapping);

	return ret;

}

EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);

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