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Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c118
1 files changed, 70 insertions, 48 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 10a171113273..7771871fa353 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -33,7 +33,6 @@
#include <linux/cpuset.h>
#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"
@@ -78,7 +77,7 @@
* ->i_mutex (generic_file_buffered_write)
* ->mmap_sem (fault_in_pages_readable->do_page_fault)
*
- * inode_wb_list_lock
+ * bdi->wb.list_lock
* sb_lock (fs/fs-writeback.c)
* ->mapping->tree_lock (__sync_single_inode)
*
@@ -96,9 +95,9 @@
* ->zone.lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->tree_lock (page_remove_rmap->set_page_dirty)
- * inode_wb_list_lock (page_remove_rmap->set_page_dirty)
+ * bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
* ->inode->i_lock (page_remove_rmap->set_page_dirty)
- * inode_wb_list_lock (zap_pte_range->set_page_dirty)
+ * bdi.wb->list_lock (zap_pte_range->set_page_dirty)
* ->inode->i_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
*
@@ -462,6 +461,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
int error;
VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageSwapBacked(page));
error = mem_cgroup_cache_charge(page, current->mm,
gfp_mask & GFP_RECLAIM_MASK);
@@ -479,8 +479,6 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
if (likely(!error)) {
mapping->nrpages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
- if (PageSwapBacked(page))
- __inc_zone_page_state(page, NR_SHMEM);
spin_unlock_irq(&mapping->tree_lock);
} else {
page->mapping = NULL;
@@ -502,22 +500,9 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
{
int ret;
- /*
- * Splice_read and readahead add shmem/tmpfs pages into the page cache
- * before shmem_readpage has a chance to mark them as SwapBacked: they
- * need to go on the anon lru below, and mem_cgroup_cache_charge
- * (called in add_to_page_cache) needs to know where they're going too.
- */
- if (mapping_cap_swap_backed(mapping))
- SetPageSwapBacked(page);
-
ret = add_to_page_cache(page, mapping, offset, gfp_mask);
- if (ret == 0) {
- if (page_is_file_cache(page))
- lru_cache_add_file(page);
- else
- lru_cache_add_anon(page);
- }
+ if (ret == 0)
+ lru_cache_add_file(page);
return ret;
}
EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
@@ -714,9 +699,16 @@ repeat:
page = radix_tree_deref_slot(pagep);
if (unlikely(!page))
goto out;
- if (radix_tree_deref_retry(page))
- goto repeat;
-
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page))
+ goto repeat;
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so return it without
+ * attempting to raise page count.
+ */
+ goto out;
+ }
if (!page_cache_get_speculative(page))
goto repeat;
@@ -753,7 +745,7 @@ struct page *find_lock_page(struct address_space *mapping, pgoff_t offset)
repeat:
page = find_get_page(mapping, offset);
- if (page) {
+ if (page && !radix_tree_exception(page)) {
lock_page(page);
/* Has the page been truncated? */
if (unlikely(page->mapping != mapping)) {
@@ -835,13 +827,14 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
{
unsigned int i;
unsigned int ret;
- unsigned int nr_found;
+ unsigned int nr_found, nr_skip;
rcu_read_lock();
restart:
nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree,
- (void ***)pages, start, nr_pages);
+ (void ***)pages, NULL, start, nr_pages);
ret = 0;
+ nr_skip = 0;
for (i = 0; i < nr_found; i++) {
struct page *page;
repeat:
@@ -849,13 +842,23 @@ repeat:
if (unlikely(!page))
continue;
- /*
- * This can only trigger when the entry at index 0 moves out
- * of or back to the root: none yet gotten, safe to restart.
- */
- if (radix_tree_deref_retry(page)) {
- WARN_ON(start | i);
- goto restart;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ WARN_ON(start | i);
+ goto restart;
+ }
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so skip over it -
+ * we only reach this from invalidate_mapping_pages().
+ */
+ nr_skip++;
+ continue;
}
if (!page_cache_get_speculative(page))
@@ -875,7 +878,7 @@ repeat:
* If all entries were removed before we could secure them,
* try again, because callers stop trying once 0 is returned.
*/
- if (unlikely(!ret && nr_found))
+ if (unlikely(!ret && nr_found > nr_skip))
goto restart;
rcu_read_unlock();
return ret;
@@ -903,7 +906,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
rcu_read_lock();
restart:
nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree,
- (void ***)pages, index, nr_pages);
+ (void ***)pages, NULL, index, nr_pages);
ret = 0;
for (i = 0; i < nr_found; i++) {
struct page *page;
@@ -912,12 +915,22 @@ repeat:
if (unlikely(!page))
continue;
- /*
- * This can only trigger when the entry at index 0 moves out
- * of or back to the root: none yet gotten, safe to restart.
- */
- if (radix_tree_deref_retry(page))
- goto restart;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ goto restart;
+ }
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so stop looking for
+ * contiguous pages.
+ */
+ break;
+ }
if (!page_cache_get_speculative(page))
goto repeat;
@@ -977,12 +990,21 @@ repeat:
if (unlikely(!page))
continue;
- /*
- * This can only trigger when the entry at index 0 moves out
- * of or back to the root: none yet gotten, safe to restart.
- */
- if (radix_tree_deref_retry(page))
- goto restart;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ goto restart;
+ }
+ /*
+ * This function is never used on a shmem/tmpfs
+ * mapping, so a swap entry won't be found here.
+ */
+ BUG();
+ }
if (!page_cache_get_speculative(page))
goto repeat;
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-15 16:09:55 +0300