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Diffstat (limited to 'include/linux/swap.h')
-rw-r--r--include/linux/swap.h71
1 files changed, 25 insertions, 46 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 38ca3df68716..62fc7499b408 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -224,13 +224,11 @@ enum {
#define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
/* Bit flag in swap_map */
-#define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
#define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */
/* Special value in first swap_map */
#define SWAP_MAP_MAX 0x3e /* Max count */
#define SWAP_MAP_BAD 0x3f /* Note page is bad */
-#define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */
/* Special value in each swap_map continuation */
#define SWAP_CONT_MAX 0x7f /* Max count */
@@ -453,16 +451,7 @@ static inline long get_nr_swap_pages(void)
}
extern void si_swapinfo(struct sysinfo *);
-int folio_alloc_swap(struct folio *folio);
-bool folio_free_swap(struct folio *folio);
-void put_swap_folio(struct folio *folio, swp_entry_t entry);
-extern swp_entry_t get_swap_page_of_type(int);
extern int add_swap_count_continuation(swp_entry_t, gfp_t);
-extern void swap_shmem_alloc(swp_entry_t, int);
-extern int swap_duplicate(swp_entry_t);
-extern int swapcache_prepare(swp_entry_t entry, int nr);
-extern void swap_free_nr(swp_entry_t entry, int nr_pages);
-extern void free_swap_and_cache_nr(swp_entry_t entry, int nr);
int swap_type_of(dev_t device, sector_t offset);
int find_first_swap(dev_t *device);
extern unsigned int count_swap_pages(int, int);
@@ -474,6 +463,29 @@ struct backing_dev_info;
extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
sector_t swap_folio_sector(struct folio *folio);
+/*
+ * If there is an existing swap slot reference (swap entry) and the caller
+ * guarantees that there is no race modification of it (e.g., PTL
+ * protecting the swap entry in page table; shmem's cmpxchg protects t
+ * he swap entry in shmem mapping), these two helpers below can be used
+ * to put/dup the entries directly.
+ *
+ * All entries must be allocated by folio_alloc_swap(). And they must have
+ * a swap count > 1. See comments of folio_*_swap helpers for more info.
+ */
+int swap_dup_entry_direct(swp_entry_t entry);
+void swap_put_entries_direct(swp_entry_t entry, int nr);
+
+/*
+ * folio_free_swap tries to free the swap entries pinned by a swap cache
+ * folio, it has to be here to be called by other components.
+ */
+bool folio_free_swap(struct folio *folio);
+
+/* Allocate / free (hibernation) exclusive entries */
+swp_entry_t swap_alloc_hibernation_slot(int type);
+void swap_free_hibernation_slot(swp_entry_t entry);
+
static inline void put_swap_device(struct swap_info_struct *si)
{
percpu_ref_put(&si->users);
@@ -501,10 +513,6 @@ static inline void put_swap_device(struct swap_info_struct *si)
#define free_pages_and_swap_cache(pages, nr) \
release_pages((pages), (nr));
-static inline void free_swap_and_cache_nr(swp_entry_t entry, int nr)
-{
-}
-
static inline void free_swap_cache(struct folio *folio)
{
}
@@ -514,25 +522,12 @@ static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
return 0;
}
-static inline void swap_shmem_alloc(swp_entry_t swp, int nr)
-{
-}
-
-static inline int swap_duplicate(swp_entry_t swp)
-{
- return 0;
-}
-
-static inline int swapcache_prepare(swp_entry_t swp, int nr)
+static inline int swap_dup_entry_direct(swp_entry_t ent)
{
return 0;
}
-static inline void swap_free_nr(swp_entry_t entry, int nr_pages)
-{
-}
-
-static inline void put_swap_folio(struct folio *folio, swp_entry_t swp)
+static inline void swap_put_entries_direct(swp_entry_t ent, int nr)
{
}
@@ -551,11 +546,6 @@ static inline int swp_swapcount(swp_entry_t entry)
return 0;
}
-static inline int folio_alloc_swap(struct folio *folio)
-{
- return -EINVAL;
-}
-
static inline bool folio_free_swap(struct folio *folio)
{
return false;
@@ -568,17 +558,6 @@ static inline int add_swap_extent(struct swap_info_struct *sis,
return -EINVAL;
}
#endif /* CONFIG_SWAP */
-
-static inline void free_swap_and_cache(swp_entry_t entry)
-{
- free_swap_and_cache_nr(entry, 1);
-}
-
-static inline void swap_free(swp_entry_t entry)
-{
- swap_free_nr(entry, 1);
-}
-
#ifdef CONFIG_MEMCG
static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
{