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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-06-07 22:38:48 +0300
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-08-02 19:34:03 +0300
commit68f2736a858324c3ec852f6c2cddd9d1c777357d (patch)
tree62c9573d493277ee9eb7edb13276570e395d8e8f /mm/zsmalloc.c
parent81218f80a70768589ee30e14a8889336f070a339 (diff)
downloadlinux-68f2736a858324c3ec852f6c2cddd9d1c777357d.tar.xz
mm: Convert all PageMovable users to movable_operations
These drivers are rather uncomfortably hammered into the address_space_operations hole. They aren't filesystems and don't behave like filesystems. They just need their own movable_operations structure, which we can point to directly from page->mapping. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'mm/zsmalloc.c')
-rw-r--r--mm/zsmalloc.c102
1 files changed, 22 insertions, 80 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 5d5fc04385b8..71d6edcbea48 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -41,7 +41,6 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
-#include <linux/magic.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/highmem.h>
@@ -59,8 +58,6 @@
#include <linux/debugfs.h>
#include <linux/zsmalloc.h>
#include <linux/zpool.h>
-#include <linux/mount.h>
-#include <linux/pseudo_fs.h>
#include <linux/migrate.h>
#include <linux/wait.h>
#include <linux/pagemap.h>
@@ -177,10 +174,6 @@ struct zs_size_stat {
static struct dentry *zs_stat_root;
#endif
-#ifdef CONFIG_COMPACTION
-static struct vfsmount *zsmalloc_mnt;
-#endif
-
/*
* We assign a page to ZS_ALMOST_EMPTY fullness group when:
* n <= N / f, where
@@ -252,7 +245,6 @@ struct zs_pool {
struct dentry *stat_dentry;
#endif
#ifdef CONFIG_COMPACTION
- struct inode *inode;
struct work_struct free_work;
#endif
/* protect page/zspage migration */
@@ -271,6 +263,7 @@ struct zspage {
unsigned int freeobj;
struct page *first_page;
struct list_head list; /* fullness list */
+ struct zs_pool *pool;
#ifdef CONFIG_COMPACTION
rwlock_t lock;
#endif
@@ -295,8 +288,6 @@ static bool ZsHugePage(struct zspage *zspage)
}
#ifdef CONFIG_COMPACTION
-static int zs_register_migration(struct zs_pool *pool);
-static void zs_unregister_migration(struct zs_pool *pool);
static void migrate_lock_init(struct zspage *zspage);
static void migrate_read_lock(struct zspage *zspage);
static void migrate_read_unlock(struct zspage *zspage);
@@ -307,10 +298,6 @@ static void kick_deferred_free(struct zs_pool *pool);
static void init_deferred_free(struct zs_pool *pool);
static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage);
#else
-static int zsmalloc_mount(void) { return 0; }
-static void zsmalloc_unmount(void) {}
-static int zs_register_migration(struct zs_pool *pool) { return 0; }
-static void zs_unregister_migration(struct zs_pool *pool) {}
static void migrate_lock_init(struct zspage *zspage) {}
static void migrate_read_lock(struct zspage *zspage) {}
static void migrate_read_unlock(struct zspage *zspage) {}
@@ -1083,6 +1070,7 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
create_page_chain(class, zspage, pages);
init_zspage(class, zspage);
+ zspage->pool = pool;
return zspage;
}
@@ -1754,33 +1742,6 @@ static void lock_zspage(struct zspage *zspage)
migrate_read_unlock(zspage);
}
-static int zs_init_fs_context(struct fs_context *fc)
-{
- return init_pseudo(fc, ZSMALLOC_MAGIC) ? 0 : -ENOMEM;
-}
-
-static struct file_system_type zsmalloc_fs = {
- .name = "zsmalloc",
- .init_fs_context = zs_init_fs_context,
- .kill_sb = kill_anon_super,
-};
-
-static int zsmalloc_mount(void)
-{
- int ret = 0;
-
- zsmalloc_mnt = kern_mount(&zsmalloc_fs);
- if (IS_ERR(zsmalloc_mnt))
- ret = PTR_ERR(zsmalloc_mnt);
-
- return ret;
-}
-
-static void zsmalloc_unmount(void)
-{
- kern_unmount(zsmalloc_mnt);
-}
-
static void migrate_lock_init(struct zspage *zspage)
{
rwlock_init(&zspage->lock);
@@ -1823,6 +1784,8 @@ static void dec_zspage_isolation(struct zspage *zspage)
zspage->isolated--;
}
+static const struct movable_operations zsmalloc_mops;
+
static void replace_sub_page(struct size_class *class, struct zspage *zspage,
struct page *newpage, struct page *oldpage)
{
@@ -1843,7 +1806,7 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage,
set_first_obj_offset(newpage, get_first_obj_offset(oldpage));
if (unlikely(ZsHugePage(zspage)))
newpage->index = oldpage->index;
- __SetPageMovable(newpage, page_mapping(oldpage));
+ __SetPageMovable(newpage, &zsmalloc_mops);
}
static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
@@ -1865,8 +1828,8 @@ static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
return true;
}
-static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
- struct page *page, enum migrate_mode mode)
+static int zs_page_migrate(struct page *newpage, struct page *page,
+ enum migrate_mode mode)
{
struct zs_pool *pool;
struct size_class *class;
@@ -1889,14 +1852,15 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
- pool = mapping->private_data;
+ /* The page is locked, so this pointer must remain valid */
+ zspage = get_zspage(page);
+ pool = zspage->pool;
/*
* The pool migrate_lock protects the race between zpage migration
* and zs_free.
*/
write_lock(&pool->migrate_lock);
- zspage = get_zspage(page);
class = zspage_class(pool, zspage);
/*
@@ -1964,31 +1928,12 @@ static void zs_page_putback(struct page *page)
migrate_write_unlock(zspage);
}
-static const struct address_space_operations zsmalloc_aops = {
+static const struct movable_operations zsmalloc_mops = {
.isolate_page = zs_page_isolate,
- .migratepage = zs_page_migrate,
+ .migrate_page = zs_page_migrate,
.putback_page = zs_page_putback,
};
-static int zs_register_migration(struct zs_pool *pool)
-{
- pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb);
- if (IS_ERR(pool->inode)) {
- pool->inode = NULL;
- return 1;
- }
-
- pool->inode->i_mapping->private_data = pool;
- pool->inode->i_mapping->a_ops = &zsmalloc_aops;
- return 0;
-}
-
-static void zs_unregister_migration(struct zs_pool *pool)
-{
- flush_work(&pool->free_work);
- iput(pool->inode);
-}
-
/*
* Caller should hold page_lock of all pages in the zspage
* In here, we cannot use zspage meta data.
@@ -2032,6 +1977,11 @@ static void kick_deferred_free(struct zs_pool *pool)
schedule_work(&pool->free_work);
}
+static void zs_flush_migration(struct zs_pool *pool)
+{
+ flush_work(&pool->free_work);
+}
+
static void init_deferred_free(struct zs_pool *pool)
{
INIT_WORK(&pool->free_work, async_free_zspage);
@@ -2043,10 +1993,12 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage)
do {
WARN_ON(!trylock_page(page));
- __SetPageMovable(page, pool->inode->i_mapping);
+ __SetPageMovable(page, &zsmalloc_mops);
unlock_page(page);
} while ((page = get_next_page(page)) != NULL);
}
+#else
+static inline void zs_flush_migration(struct zs_pool *pool) { }
#endif
/*
@@ -2324,9 +2276,6 @@ struct zs_pool *zs_create_pool(const char *name)
/* debug only, don't abort if it fails */
zs_pool_stat_create(pool, name);
- if (zs_register_migration(pool))
- goto err;
-
/*
* Not critical since shrinker is only used to trigger internal
* defragmentation of the pool which is pretty optional thing. If
@@ -2348,7 +2297,7 @@ void zs_destroy_pool(struct zs_pool *pool)
int i;
zs_unregister_shrinker(pool);
- zs_unregister_migration(pool);
+ zs_flush_migration(pool);
zs_pool_stat_destroy(pool);
for (i = 0; i < ZS_SIZE_CLASSES; i++) {
@@ -2380,14 +2329,10 @@ static int __init zs_init(void)
{
int ret;
- ret = zsmalloc_mount();
- if (ret)
- goto out;
-
ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare",
zs_cpu_prepare, zs_cpu_dead);
if (ret)
- goto hp_setup_fail;
+ goto out;
#ifdef CONFIG_ZPOOL
zpool_register_driver(&zs_zpool_driver);
@@ -2397,8 +2342,6 @@ static int __init zs_init(void)
return 0;
-hp_setup_fail:
- zsmalloc_unmount();
out:
return ret;
}
@@ -2408,7 +2351,6 @@ static void __exit zs_exit(void)
#ifdef CONFIG_ZPOOL
zpool_unregister_driver(&zs_zpool_driver);
#endif
- zsmalloc_unmount();
cpuhp_remove_state(CPUHP_MM_ZS_PREPARE);
zs_stat_exit();