[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@xxxxxxxxx: adapt to new remove_from_page_cache function]
Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxx>
Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Reviewed-by: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Rik Van Riel <riel@xxxxxxxxxx>
Cc: Jan Beulich <JBeulich@xxxxxxxxxx>
Cc: Andreas Dilger <adilger@xxxxxxx>
Cc: Ted Ts'o <tytso@xxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Joel Becker <joel.becker@xxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
---
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 <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(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 <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
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 <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, 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 <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 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 <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
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);
--
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