From: Johannes Weiner <jwei...@fb.com>
__read_swap_cache_async() has a misleading name. All it does is look
up or create a page in swapcache; it doesn't initiate any IO.
The swapcache has many parallels to the page cache, and shares naming
schemes with it elsewhere. Analogous to the cache lookup and creation
API, rename __read_swap_cache_async() find_or_create_swap_cache() and
lookup_swap_cache() to find_swap_cache().
Signed-off-by: Johannes Weiner <jwei...@fb.com>
Signed-off-by: Josef Bacik <jo...@toxicpanda.com>
---
include/linux/swap.h | 14 ++++++++------
mm/memory.c | 2 +-
mm/shmem.c | 2 +-
mm/swap_state.c | 43 ++++++++++++++++++++++---------------------
mm/zswap.c | 8 ++++----
5 files changed, 36 insertions(+), 33 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8e2c11e692ba..293a84c34448 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -412,15 +412,17 @@ extern void __delete_from_swap_cache(struct page *);
extern void delete_from_swap_cache(struct page *);
extern void free_page_and_swap_cache(struct page *);
extern void free_pages_and_swap_cache(struct page **, int);
-extern struct page *lookup_swap_cache(swp_entry_t entry,
- struct vm_area_struct *vma,
- unsigned long addr);
+extern struct page *find_swap_cache(swp_entry_t entry,
+ struct vm_area_struct *vma,
+ unsigned long addr);
+extern struct page *find_or_create_swap_cache(swp_entry_t entry,
+ gfp_t gfp_mask,
+ struct vm_area_struct *vma,
+ unsigned long addr,
+ bool *created);
extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
struct vm_area_struct *vma, unsigned long addr,
bool do_poll);
-extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t,
- struct vm_area_struct *vma, unsigned long addr,
- bool *new_page_allocated);
extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
diff --git a/mm/memory.c b/mm/memory.c
index 433075f722ea..6f8abde84986 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2935,7 +2935,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
delayacct_set_flag(DELAYACCT_PF_SWAPIN);
- page = lookup_swap_cache(entry, vma, vmf->address);
+ page = find_swap_cache(entry, vma, vmf->address);
swapcache = page;
if (!page) {
diff --git a/mm/shmem.c b/mm/shmem.c
index 0376c124b043..9854903ae92f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1679,7 +1679,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t
index,
if (swap.val) {
/* Look it up and read it in.. */
- page = lookup_swap_cache(swap, NULL, 0);
+ page = find_swap_cache(swap, NULL, 0);
if (!page) {
/* Or update major stats only when swapin succeeds?? */
if (fault_type) {
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ecee9c6c4cc1..bae758e19f7a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -330,8 +330,8 @@ static inline bool swap_use_vma_readahead(void)
* lock getting page table operations atomic even if we drop the page
* lock before returning.
*/
-struct page *lookup_swap_cache(swp_entry_t entry, struct vm_area_struct *vma,
- unsigned long addr)
+struct page *find_swap_cache(swp_entry_t entry, struct vm_area_struct *vma,
+ unsigned long addr)
{
struct page *page;
@@ -374,19 +374,20 @@ struct page *lookup_swap_cache(swp_entry_t entry, struct
vm_area_struct *vma,
return page;
}
-struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
+struct page *find_or_create_swap_cache(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma, unsigned long addr,
- bool *new_page_allocated)
+ bool *created)
{
struct page *found_page, *new_page = NULL;
struct address_space *swapper_space = swap_address_space(entry);
int err;
- *new_page_allocated = false;
+
+ *created = false;
do {
/*
* First check the swap cache. Since this is normally
- * called after lookup_swap_cache() failed, re-calling
+ * called after find_swap_cache() failed, re-calling
* that would confuse statistics.
*/
found_page = find_get_page(swapper_space, swp_offset(entry));
@@ -449,7 +450,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry,
gfp_t gfp_mask,
* Initiate read into locked page and return.
*/
lru_cache_add_anon(new_page);
- *new_page_allocated = true;
+ *created = true;
return new_page;
}
radix_tree_preload_end();
@@ -475,14 +476,14 @@ struct page *__read_swap_cache_async(swp_entry_t entry,
gfp_t gfp_mask,
struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma, unsigned long addr, bool do_poll)
{
- bool page_was_allocated;
- struct page *retpage = __read_swap_cache_async(entry, gfp_mask,
- vma, addr, &page_was_allocated);
+ struct page *page;
+ bool created;
- if (page_was_allocated)
- swap_readpage(retpage, do_poll);
+ page = find_or_create_swap_cache(entry, gfp_mask, vma, addr, &created);
+ if (created)
+ swap_readpage(page, do_poll);
- return retpage;
+ return page;
}
static unsigned int __swapin_nr_pages(unsigned long prev_offset,
@@ -573,7 +574,7 @@ struct page *swap_cluster_readahead(swp_entry_t entry,
gfp_t gfp_mask,
unsigned long mask;
struct swap_info_struct *si = swp_swap_info(entry);
struct blk_plug plug;
- bool do_poll = true, page_allocated;
+ bool do_poll = true, created;
struct vm_area_struct *vma = vmf->vma;
unsigned long addr = vmf->address;
@@ -593,12 +594,12 @@ struct page *swap_cluster_readahead(swp_entry_t entry,
gfp_t gfp_mask,
blk_start_plug(&plug);
for (offset = start_offset; offset <= end_offset ; offset++) {
/* Ok, do the async read-ahead now */
- page = __read_swap_cache_async(
+ page = find_or_create_swap_cache(
swp_entry(swp_type(entry), offset),
- gfp_mask, vma, addr, &page_allocated);
+ gfp_mask, vma, addr, &created);
if (!page)
continue;
- if (page_allocated) {
+ if (created) {
swap_readpage(page, false);
if (offset != entry_offset) {
SetPageReadahead(page);
@@ -738,7 +739,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry,
gfp_t gfp_mask,
pte_t *pte, pentry;
swp_entry_t entry;
unsigned int i;
- bool page_allocated;
+ bool created;
struct vma_swap_readahead ra_info = {0,};
swap_ra_info(vmf, &ra_info);
@@ -756,11 +757,11 @@ static struct page *swap_vma_readahead(swp_entry_t
fentry, gfp_t gfp_mask,
entry = pte_to_swp_entry(pentry);
if (unlikely(non_swap_entry(entry)))
continue;
- page = __read_swap_cache_async(entry, gfp_mask, vma,
- vmf->address, &page_allocated);
+ page = find_or_create_swap_cache(entry, gfp_mask, vma,
+ vmf->address, &created);
if (!page)
continue;
- if (page_allocated) {
+ if (created) {
swap_readpage(page, false);
if (i != ra_info.offset) {
SetPageReadahead(page);
diff --git a/mm/zswap.c b/mm/zswap.c
index cd91fd9d96b8..6f05faa75766 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -823,11 +823,11 @@ enum zswap_get_swap_ret {
static int zswap_get_swap_cache_page(swp_entry_t entry,
struct page **retpage)
{
- bool page_was_allocated;
+ bool created;
- *retpage = __read_swap_cache_async(entry, GFP_KERNEL,
- NULL, 0, &page_was_allocated);
- if (page_was_allocated)
+ *retpage = find_or_create_swap_cache(entry, GFP_KERNEL,
+ NULL, 0, &created);
+ if (created)
return ZSWAP_SWAPCACHE_NEW;
if (!*retpage)
return ZSWAP_SWAPCACHE_FAIL;
--
2.14.3
