Add extended attributes to ext2/3

RFC PATCH In review [email protected] 6 participants 11 messages Oct 8, 2002 – Oct 10, 2002

Subsystems (5)

Memory management VFS MM core MGLRU +1 more subsystems

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lore

[email protected]

author

2002-10-08 18:02 UTC #0 lore raw

RFC PATCH 1/4 Add extended attributes to ext2/3

This is the first of four patches which add extended attribute support to the ext2 and ext3 filesystems. It is a port of Andreas Gruenbacher's patches, which have been well tested and in a number of distributions (including RH 8, if I'm not mistaken) already. I just ported it to 2.5 (these patches are versus 2.5.40). As always, since I touched the code last, any problems in it are my fault. :-)

These patches are prerequisite for the port of the Andreas Gruenbacher's ACL patches to 2.5, which I'm currently working on. But given the short time-frame before feature freeze, I'd like to get these out for review ASAP. Please comment and bleed on them.

This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
#

# include/linux/cache_def.h |   15 +++++++++++++++
# kernel/ksyms.c            |    3 +++
# mm/vmscan.c               |   29 +++++++++++++++++++++++++++++
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/04	[email protected]	1.665
# Port of the 0.8.50 cache-def patch.
# --------------------------------------------
#
diff -Nru a/include/linux/cache_def.h b/include/linux/cache_def.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/linux/cache_def.h	Tue Oct  8 13:52:08 2002
@@ -0,0 +1,15 @@
+/*
+ * linux/cache_def.h
+ * Handling of caches defined in drivers, filesystems, ...
+ *
+ * Copyright (C) 2002 by Andreas Gruenbacher, <[email protected]>
+ */
+
+struct cache_definition {
+	const char *name;
+	void (*shrink)(int, unsigned int);
+	struct list_head link;
+};
+
+extern void register_cache(struct cache_definition *);
+extern void unregister_cache(struct cache_definition *);
diff -Nru a/kernel/ksyms.c b/kernel/ksyms.c
--- a/kernel/ksyms.c	Tue Oct  8 13:52:08 2002
+++ b/kernel/ksyms.c	Tue Oct  8 13:52:08 2002
@@ -31,6 +31,7 @@
 #include <linux/genhd.h>
 #include <linux/blkpg.h>
 #include <linux/swap.h>
+#include <linux/cache_def.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
 #include <linux/iobuf.h>
@@ -106,6 +107,8 @@
 EXPORT_SYMBOL(kmem_cache_alloc);
 EXPORT_SYMBOL(kmem_cache_free);
 EXPORT_SYMBOL(kmem_cache_size);
+EXPORT_SYMBOL(register_cache);
+EXPORT_SYMBOL(unregister_cache);
 EXPORT_SYMBOL(kmalloc);
 EXPORT_SYMBOL(kfree);
 EXPORT_SYMBOL(vfree);
diff -Nru a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c	Tue Oct  8 13:52:08 2002
+++ b/mm/vmscan.c	Tue Oct  8 13:52:08 2002
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/kernel_stat.h>
 #include <linux/swap.h>
+#include <linux/cache_def.h>
 #include <linux/pagemap.h>
 #include <linux/init.h>
 #include <linux/highmem.h>
@@ -76,6 +77,33 @@
 #define shrink_dqcache_memory(ratio, gfp_mask) do { } while (0)
 #endif

+static LIST_HEAD(cache_definitions);
+
+/* BKL must be held */
+void register_cache(struct cache_definition *cache) +{
+ list_add(&cache->link, &cache_definitions);
+}
+
+/* BLK must be held */
+void unregister_cache(struct cache_definition *cache) +{
+ list_del(&cache->link);
+}
+
+static void shrink_other_caches(int ratio, int gfp_mask) +{
+ struct list_head *p = cache_definitions.prev;
+
+ while (p != &cache_definitions) {
+ struct cache_definition *cache =
+ list_entry(p, struct cache_definition, link);
+
+ cache->shrink(ratio, gfp_mask); /* BLK held */
+ p = p->prev;
+ }
+}
+
/* Must be called with page's pte_chain_lock held. */ static inline int page_mapping_inuse(struct page * page) {
@@ -614,6 +642,7 @@
shrink_dcache_memory(ratio, gfp_mask); shrink_icache_memory(ratio, gfp_mask); shrink_dqcache_memory(ratio, gfp_mask);
+ shrink_other_caches(ratio, gfp_mask);
return nr_pages;
}

Christoph Hellwig

2002-10-08 18:13 UTC #1 lore raw

Quoted 5 lines · On Tue, Oct 08, 2002 at 02:08:11PM -0400, [email protected] wrote:

This is the first of four patches which add extended attribute support to the ext2 and ext3 filesystems. It is a port of Andreas Gruenbacher's patches, which have been well tested and in a number of distributions (including RH 8, if I'm not mistaken) already.

RH backed it out after the second or third beta due to bugginess..

Quoted 3 lines

This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.

I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.

Doing this outside slab is not a good idea (and XFS currently does it too - in it's own code which should be replaced with Ed's one)

Andrew Morton

2002-10-08 18:33 UTC #2 lore raw

Quoted 14 lines · Christoph Hellwig

Quoted 5 lines · On Tue, Oct 08, 2002 at 02:08:11PM -0400, [email protected] wrote:
This is the first of four patches which add extended attribute support to the ext2 and ext3 filesystems. It is a port of Andreas Gruenbacher's patches, which have been well tested and in a number of distributions (including RH 8, if I'm not mistaken) already.
RH backed it out after the second or third beta due to bugginess..
Quoted 3 lines
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.

Quoted 5 lines

I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.
Doing this outside slab is not a good idea (and XFS currently does it too - in it's own code which should be replaced with Ed's one)

Yup, although that's a fairly minor point in this context..

The shrinker callback code is not actually in Linus's kernel at present. I'm kind of sitting on it until I've had time to ponder the dirty great lock which Ed added ;)

Andreas Gruenbacher

2002-10-08 18:43 UTC #3 lore raw

Quoted 9 lines · Andrew Morton

[...]
Quoted 8 lines
Quoted 3 lines
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.

Quoted 8 lines

Quoted 2 lines
Doing this outside slab is not a good idea (and XFS currently does it too - in it's own code which should be replaced with Ed's one)
Yup, although that's a fairly minor point in this context..
The shrinker callback code is not actually in Linus's kernel at present. I'm kind of sitting on it until I've had time to ponder the dirty great lock which Ed added ;)

Switching to Ed's code once it's in the kernel may be worthwhile; until then the dumb shrinking approaah doesn't to do much harm IMHO.

--Andreas.

Rik van Riel

2002-10-08 19:12 UTC #4 lore raw

Quoted 2 lines · Andreas Gruenbacher

Switching to Ed's code once it's in the kernel may be worthwhile; until then the dumb shrinking approaah doesn't to do much harm IMHO.

Agreed.

Rik

Signature · 4 lines

A: No.
Q: Should I include quotations after my reply?

http://www.surriel.com/		http://distro.conectiva.com/

Andrew Morton

2002-10-10 06:51 UTC #5 lore raw

In reply to Andreas Gruenbacher

Quoted 3 lines · Andreas Gruenbacher

Switching to Ed's code once it's in the kernel may be worthwhile; until then the dumb shrinking approaah doesn't to do much harm IMHO.

I've done another round on Ed's registration and shrinking API. Here's what we have. The reiserfs team need the shrinker registration API as well.

(Some of the below code still has wet paint ;))

Quoted 1 line

From Ed Tomlinson, then mauled by yours truly.

The current shrinking of the dentry, inode and dquot caches seems to work OK, but it is slightly CPU-inefficient: we call the shrinking functions many times, for tiny numbers of objects.

So here, we just batch that up - shrinking happens at the same rate but we perform it in larger units of work.

To do this, we need a way of knowing how many objects are currently in use by individual caches. slab does not actually track this information, but the existing shrinkable caches do have this on hand. So rather than adding the counters to slab, we require that the shrinker callback functions keep their own count - we query that via the callback.

We add a simple registration API which is exported to modules. A subsystem may register its own callback function via set_shrinker().

set_shrinker() simply takes a function pointer. The function is called with

	int (*shrinker)(int nr_to_shrink, unsigned int gfp_mask);

The shrinker callback must scan nr_to_scan' objects and free all freeable scanned objects. Note: it doesn't have to *free* nr_to_scan' objects. It need only scan that many. Which is a fairly pedantic detail, really.

The shrinker callback must return the number of objects which are in its cache at the end of the scanning attempt. It will be called with nr_to_scan == 0 when we're just querying the cache size.

The set_shrinker() registration API is passed a hint as to how many disk seeks a single cache object is worth. Everything uses "2" at present.

- shrink_icache_memory() is no longer exported to modules.

- shrink_icache_memory() is now static to fs/inode.c

- prune_icache() is now static to fs/inode.c, and made inline (single caller)

- shrink_dcache_memory() is made static to fs/dcache.c

- prune_dcache() is no longer exported to modules

- prune_dcache() is made static to fs/dcache.c

- shrink_dqcache_memory() is made static to fs/dquot.c

- All the quota init code has been moved from fs/dcache.c into fs/dquot.c

- All modifications to inodes_stat.nr_inodes are now inside inode_lock - the dispose_list one was racy.

 fs/dcache.c            |   50 ++++++++------------
 fs/dquot.c             |   28 ++++++++---
 fs/inode.c             |   49 ++++++++++----------
 include/linux/dcache.h |   11 ----
 include/linux/mm.h     |   23 +++++++++
 kernel/ksyms.c         |    3 -
 mm/vmscan.c            |  119 ++++++++++++++++++++++++++++++++++++-------------
 7 files changed, 179 insertions(+), 104 deletions(-)

fs/dcache.c renamed from fs/dcache.c~batched-slab-asap +20 ~~-30~~

@@ -328,7 +328,7 @@ static inline void prune_one_dentry(stru
  * all the dentries are in use.
  */
  
-void prune_dcache(int count)
+static void prune_dcache(int count)
 {
 	spin_lock(&dcache_lock);
 	for (; count ; count--) {

@@ -572,25 +572,24 @@ void shrink_dcache_anon(struct list_head
  * This is called from kswapd when we think we need some
  * more memory. 
  */
-int shrink_dcache_memory(int ratio, unsigned int gfp_mask)
+static int shrink_dcache_memory(int nr, unsigned int gfp_mask)
 {
-	int entries = dentry_stat.nr_dentry / ratio + 1;
-	/*
-	 * Nasty deadlock avoidance.
-	 *
-	 * ext2_new_block->getblk->GFP->shrink_dcache_memory->prune_dcache->
-	 * prune_one_dentry->dput->dentry_iput->iput->inode->i_sb->s_op->
-	 * put_inode->ext2_discard_prealloc->ext2_free_blocks->lock_super->
-	 * DEADLOCK.
-	 *
-	 * We should make sure we don't hold the superblock lock over
-	 * block allocations, but for now:
-	 */
-	if (!(gfp_mask & __GFP_FS))
-		return 0;
-
-	prune_dcache(entries);
-	return entries;
+	if (nr) {
+		/*
+		 * Nasty deadlock avoidance.
+		 *
+	 	 * ext2_new_block->getblk->GFP->shrink_dcache_memory->
+		 * prune_dcache->prune_one_dentry->dput->dentry_iput->iput->
+		 * inode->i_sb->s_op->put_inode->ext2_discard_prealloc->
+		 * ext2_free_blocks->lock_super->DEADLOCK.
+	 	 *
+	 	 * We should make sure we don't hold the superblock lock over
+	 	 * block allocations, but for now:
+		 */
+		if (gfp_mask & __GFP_FS)
+			prune_dcache(nr);
+	}
+	return dentry_stat.nr_dentry;
 }
 
 #define NAME_ALLOC_LEN(len)	((len+16) & ~15)

@@ -1330,6 +1329,8 @@ static void __init dcache_init(unsigned 
 					 NULL, NULL);
 	if (!dentry_cache)
 		panic("Cannot create dentry cache");
+	
+	set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
 
 #if PAGE_SHIFT < 13
 	mempages >>= (13 - PAGE_SHIFT);

@@ -1375,9 +1376,6 @@ kmem_cache_t *names_cachep;
 /* SLAB cache for file structures */
 kmem_cache_t *filp_cachep;
 
-/* SLAB cache for dquot structures */
-kmem_cache_t *dquot_cachep;
-
 EXPORT_SYMBOL(d_genocide);
 
 extern void bdev_cache_init(void);

@@ -1397,14 +1395,6 @@ void __init vfs_caches_init(unsigned lon
 	if(!filp_cachep)
 		panic("Cannot create filp SLAB cache");
 
-#if defined (CONFIG_QUOTA)
-	dquot_cachep = kmem_cache_create("dquot", 
-			sizeof(struct dquot), sizeof(unsigned long) * 4,
-			SLAB_HWCACHE_ALIGN, NULL, NULL);
-	if (!dquot_cachep)
-		panic("Cannot create dquot SLAB cache");
-#endif
-
 	dcache_init(mempages);
 	inode_init(mempages);
 	files_init(mempages);

fs/dquot.c renamed from fs/dquot.c~batched-slab-asap +20 -8

@@ -55,6 +55,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
+#include <linux/mm.h>
 #include <linux/time.h>
 #include <linux/types.h>
 #include <linux/string.h>

@@ -481,14 +482,14 @@ static void prune_dqcache(int count)
  * more memory
  */
 
-int shrink_dqcache_memory(int ratio, unsigned int gfp_mask)
+static int shrink_dqcache_memory(int nr, unsigned int gfp_mask)
 {
-	int entries = dqstats.allocated_dquots / ratio + 1;
-
-	lock_kernel();
-	prune_dqcache(entries);
-	unlock_kernel();
-	return entries;
+	if (nr) {
+		lock_kernel();
+		prune_dqcache(nr);
+		unlock_kernel();
+	}
+	return dqstats.allocated_dquots;
 }
 
 /*

@@ -1490,6 +1491,9 @@ static ctl_table sys_table[] = {
 	{},
 };
 
+/* SLAB cache for dquot structures */
+kmem_cache_t *dquot_cachep;
+
 static int __init dquot_init(void)
 {
 	int i;

@@ -1499,9 +1503,17 @@ static int __init dquot_init(void)
 		INIT_LIST_HEAD(dquot_hash + i);
 	printk(KERN_NOTICE "VFS: Disk quotas v%s\n", __DQUOT_VERSION__);
 
+	dquot_cachep = kmem_cache_create("dquot", 
+			sizeof(struct dquot), sizeof(unsigned long) * 4,
+			SLAB_HWCACHE_ALIGN, NULL, NULL);
+	if (!dquot_cachep)
+		panic("Cannot create dquot SLAB cache");
+
+	set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
+
 	return 0;
 }
-__initcall(dquot_init);
+module_init(dquot_init);
 
 EXPORT_SYMBOL(register_quota_format);
 EXPORT_SYMBOL(unregister_quota_format);

fs/inode.c renamed from fs/inode.c~batched-slab-asap +25 ~~-24~~

81 lines not on this page · raw message

include/linux/mm.h renamed from include/linux/mm.h~batched-slab-asap +23 -0

@@ -392,6 +392,29 @@ extern	int free_hugepages(struct vm_area
 
 
 /*
+ * Prototype to add a shrinker callback for ageable caches.
+ * 
+ * These functions are passed a count `nr_to_scan' and a gfpmask.  They should
+ * scan `nr_to_scan' objects, attempting to free them.
+ *
+ * The callback must the number of objects which remain in the cache.
+ *
+ * The callback will be passes nr_to_scan == 0 when the VM is querying the
+ * cache size, so a fastpath for that case is appropriate.
+ */
+typedef int (*shrinker_t)(int nr_to_scan, unsigned int gfp_mask);
+
+/*
+ * Add an aging callback.  The int is the number of 'seeks' it takes
+ * to recreate one of the objects that these functions age.
+ */
+
+#define DEFAULT_SEEKS 2
+struct shrinker;
+extern struct shrinker *set_shrinker(int, shrinker_t);
+extern void remove_shrinker(struct shrinker *shrinker);
+
+/*
  * If the mapping doesn't provide a set_page_dirty a_op, then
  * just fall through and assume that it wants buffer_heads.
  * FIXME: make the method unconditional.

mm/vmscan.c renamed from mm/vmscan.c~batched-slab-asap +89 ~~-30~~

137 lines not on this page · raw message

kernel/ksyms.c renamed from kernel/ksyms.c~batched-slab-asap +2 -1

@@ -105,6 +105,8 @@ EXPORT_SYMBOL(kmem_cache_shrink);
 EXPORT_SYMBOL(kmem_cache_alloc);
 EXPORT_SYMBOL(kmem_cache_free);
 EXPORT_SYMBOL(kmem_cache_size);
+EXPORT_SYMBOL(set_shrinker);
+EXPORT_SYMBOL(remove_shrinker);
 EXPORT_SYMBOL(kmalloc);
 EXPORT_SYMBOL(kfree);
 EXPORT_SYMBOL(vfree);

@@ -248,7 +250,6 @@ EXPORT_SYMBOL(dput);
 EXPORT_SYMBOL(have_submounts);
 EXPORT_SYMBOL(d_find_alias);
 EXPORT_SYMBOL(d_prune_aliases);
-EXPORT_SYMBOL(prune_dcache);
 EXPORT_SYMBOL(shrink_dcache_sb);
 EXPORT_SYMBOL(shrink_dcache_parent);
 EXPORT_SYMBOL(shrink_dcache_anon);

include/linux/dcache.h renamed from include/linux/dcache.h~batched-slab-asap +0 ~~-11~~

@@ -180,17 +180,6 @@ extern void shrink_dcache_parent(struct 
 extern void shrink_dcache_anon(struct list_head *);
 extern int d_invalidate(struct dentry *);
 
-/* dcache memory management */
-extern int shrink_dcache_memory(int, unsigned int);
-extern void prune_dcache(int);
-
-/* icache memory management (defined in linux/fs/inode.c) */
-extern int shrink_icache_memory(int, unsigned int);
-extern void prune_icache(int);
-
-/* quota cache memory management (defined in linux/fs/dquot.c) */
-extern int shrink_dqcache_memory(int, unsigned int);
-
 /* only used at mount-time */
 extern struct dentry * d_alloc_root(struct inode *);

Theodore Ts'o

author

2002-10-08 18:35 UTC #6 lore raw

In reply to Christoph Hellwig

Quoted 6 lines · Christoph Hellwig

Quoted 3 lines
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.

Can you give me a pointer to his stuff? Thanks!

- Ted

Quoted 2 lines

Doing this outside slab is not a good idea (and XFS currently does it too - in it's own code which should be replaced with Ed's one)

Christoph Hellwig

2002-10-08 18:45 UTC #7 lore raw

Quoted 9 lines · Theodore Ts'o

Quoted 6 lines · Christoph Hellwig
Quoted 3 lines
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.
Can you give me a pointer to his stuff? Thanks!

It is/was in akpm's -mm tree (http://www.zip.com.au/~akpm/linux/patches/2.5/).
Ed, do you have a pointer to your most recent patch?

Ed Tomlinson

2002-10-08 22:36 UTC #8 lore raw

Quoted 10 lines · Christoph Hellwig

Quoted 9 lines · Theodore Ts'o
Quoted 7 lines · Christoph Hellwig
Quoted 3 lines
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
I'd suggest Ed Tomlinson's much saner interface that adds a third callbackj to kmem_cache_t (similar to the Solaris implementation) instead.

Quoted 5 lines

Quoted 1 line
Can you give me a pointer to his stuff? Thanks!
It is/was in akpm's -mm tree
(http://www.zip.com.au/~akpm/linux/patches/2.5/). Ed, do you have a pointer to your most recent patch?

Its in Andrew's tree.

Rik van Riel

2002-10-08 18:15 UTC #9 lore raw

In reply to [email protected]

Quoted 5 lines · On Tue, 8 Oct 2002 [email protected] wrote:

This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
+/* BKL must be held */

... but it isn't. Also, kswapd isn't holding the bkl while traversing the list.

Review

Quoted 4 lines

(quoted diff) +4 -0

+void register_cache(struct cache_definition *cache)
+{
+	list_add(&cache->link, &cache_definitions);
+}

I suspect you'll want a semaphore for the cache_definitions list.

cheers,

Rik

Signature · 4 lines

A: No.
Q: Should I include quotations after my reply?

http://www.surriel.com/		http://distro.conectiva.com/

Andreas Gruenbacher

2002-10-08 18:53 UTC #10 lore raw

Quoted 10 lines · Rik van Riel

Quoted 5 lines · On Tue, 8 Oct 2002 [email protected] wrote:
This first patch creates a generic interface for registering caches with the VM subsystem so that they can react appropriately to memory pressure.
+/* BKL must be held */
... but it isn't. Also, kswapd isn't holding the bkl while traversing the list.

Quoted 7 lines

Review
Quoted 4 lines
(quoted diff) +4 -0
+void register_cache(struct cache_definition *cache)
+{
+	list_add(&cache->link, &cache_definitions);
+}
I suspect you'll want a semaphore for the cache_definitions list.

My apologies. This has slipped me; I had in fact added a semaphore in a different branch. Here is a fixed version.

--Andreas.

include/linux/cache_def.h new file +15 -0

diff -Nru a/include/linux/cache_def.h b/include/linux/cache_def.h
@@ -0,0 +1,15 @@
+/*
+ * linux/cache_def.h
+ * Handling of caches defined in drivers, filesystems, ...
+ *
+ * Copyright (C) 2002 by Andreas Gruenbacher, <[email protected]>
+ */
+
+struct cache_definition {
+	const char *name;
+	void (*shrink)(int, unsigned int);
+	struct list_head link;
+};
+
+extern void register_cache(struct cache_definition *);
+extern void unregister_cache(struct cache_definition *);

kernel/ksyms.c +3 -0

@@ -31,6 +31,7 @@
 #include <linux/genhd.h>
 #include <linux/blkpg.h>
 #include <linux/swap.h>
+#include <linux/cache_def.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
 #include <linux/iobuf.h>

@@ -106,6 +107,8 @@
 EXPORT_SYMBOL(kmem_cache_alloc);
 EXPORT_SYMBOL(kmem_cache_free);
 EXPORT_SYMBOL(kmem_cache_size);
+EXPORT_SYMBOL(register_cache);
+EXPORT_SYMBOL(unregister_cache);
 EXPORT_SYMBOL(kmalloc);
 EXPORT_SYMBOL(kfree);
 EXPORT_SYMBOL(vfree);

mm/vmscan.c +35 -0

@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/kernel_stat.h>
 #include <linux/swap.h>
+#include <linux/cache_def.h>
 #include <linux/pagemap.h>
 #include <linux/init.h>
 #include <linux/highmem.h>

@@ -76,6 +77,39 @@
 #define shrink_dqcache_memory(ratio, gfp_mask) do { } while (0)
 #endif
 
+static DECLARE_MUTEX(other_caches_sem);
+static LIST_HEAD(cache_definitions);
+
+void register_cache(struct cache_definition *cache)
+{
+	down(&other_caches_sem);
+	list_add(&cache->link, &cache_definitions);
+	up(&other_caches_sem);
+}
+
+void unregister_cache(struct cache_definition *cache)
+{
+	down(&other_caches_sem);
+	list_del(&cache->link);
+	up(&other_caches_sem);
+}
+
+static void shrink_other_caches(int ratio, int gfp_mask)
+{
+	struct list_head *p;
+
+	down(&other_caches_sem);
+	p = cache_definitions.prev;
+	while (p != &cache_definitions) {
+		struct cache_definition *cache =
+			list_entry(p, struct cache_definition, link);
+
+		cache->shrink(ratio, gfp_mask);
+		p = p->prev;
+	}
+	up(&other_caches_sem);
+}
+
 /* Must be called with page's pte_chain_lock held. */
 static inline int page_mapping_inuse(struct page * page)
 {

@@ -614,6 +648,7 @@
 	shrink_dcache_memory(ratio, gfp_mask);
 	shrink_icache_memory(ratio, gfp_mask);
 	shrink_dqcache_memory(ratio, gfp_mask);
+	shrink_other_caches(ratio, gfp_mask);
 	return nr_pages;
 }