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-rw-r--r--mm/filemap.c146
1 files changed, 88 insertions, 58 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index df2006ba0cfa..6dd9a2274c80 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -281,11 +281,11 @@ EXPORT_SYMBOL(delete_from_page_cache);
* @pvec: pagevec with pages to delete
*
* The function walks over mapping->i_pages and removes pages passed in @pvec
- * from the mapping. The function expects @pvec to be sorted by page index
- * and is optimised for it to be dense.
+ * from the mapping. The function expects @pvec to be sorted by page index.
* It tolerates holes in @pvec (mapping entries at those indices are not
* modified). The function expects only THP head pages to be present in the
- * @pvec.
+ * @pvec and takes care to delete all corresponding tail pages from the
+ * mapping as well.
*
* The function expects the i_pages lock to be held.
*/
@@ -294,44 +294,40 @@ static void page_cache_delete_batch(struct address_space *mapping,
{
XA_STATE(xas, &mapping->i_pages, pvec->pages[0]->index);
int total_pages = 0;
- int i = 0;
+ int i = 0, tail_pages = 0;
struct page *page;
mapping_set_update(&xas, mapping);
xas_for_each(&xas, page, ULONG_MAX) {
- if (i >= pagevec_count(pvec))
+ if (i >= pagevec_count(pvec) && !tail_pages)
break;
-
- /* A swap/dax/shadow entry got inserted? Skip it. */
if (xa_is_value(page))
continue;
- /*
- * A page got inserted in our range? Skip it. We have our
- * pages locked so they are protected from being removed.
- * If we see a page whose index is higher than ours, it
- * means our page has been removed, which shouldn't be
- * possible because we're holding the PageLock.
- */
- if (page != pvec->pages[i]) {
- VM_BUG_ON_PAGE(page->index > pvec->pages[i]->index,
- page);
- continue;
- }
-
- WARN_ON_ONCE(!PageLocked(page));
-
- if (page->index == xas.xa_index)
+ if (!tail_pages) {
+ /*
+ * Some page got inserted in our range? Skip it. We
+ * have our pages locked so they are protected from
+ * being removed.
+ */
+ if (page != pvec->pages[i]) {
+ VM_BUG_ON_PAGE(page->index >
+ pvec->pages[i]->index, page);
+ continue;
+ }
+ WARN_ON_ONCE(!PageLocked(page));
+ if (PageTransHuge(page) && !PageHuge(page))
+ tail_pages = HPAGE_PMD_NR - 1;
page->mapping = NULL;
- /* Leave page->index set: truncation lookup relies on it */
-
- /*
- * Move to the next page in the vector if this is a regular
- * page or the index is of the last sub-page of this compound
- * page.
- */
- if (page->index + (1UL << compound_order(page)) - 1 ==
- xas.xa_index)
+ /*
+ * Leave page->index set: truncation lookup relies
+ * upon it
+ */
i++;
+ } else {
+ VM_BUG_ON_PAGE(page->index + HPAGE_PMD_NR - tail_pages
+ != pvec->pages[i]->index, page);
+ tail_pages--;
+ }
xas_store(&xas, NULL);
total_pages++;
}
@@ -1498,7 +1494,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
{
XA_STATE(xas, &mapping->i_pages, offset);
- struct page *page;
+ struct page *head, *page;
rcu_read_lock();
repeat:
@@ -1513,19 +1509,25 @@ repeat:
if (!page || xa_is_value(page))
goto out;
- if (!page_cache_get_speculative(page))
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
+ goto repeat;
+
+ /* The page was split under us? */
+ if (compound_head(page) != head) {
+ put_page(head);
goto repeat;
+ }
/*
- * Has the page moved or been split?
+ * Has the page moved?
* This is part of the lockless pagecache protocol. See
* include/linux/pagemap.h for details.
*/
if (unlikely(page != xas_reload(&xas))) {
- put_page(page);
+ put_page(head);
goto repeat;
}
- page = find_subpage(page, offset);
out:
rcu_read_unlock();
@@ -1707,6 +1709,7 @@ unsigned find_get_entries(struct address_space *mapping,
rcu_read_lock();
xas_for_each(&xas, page, ULONG_MAX) {
+ struct page *head;
if (xas_retry(&xas, page))
continue;
/*
@@ -1717,13 +1720,17 @@ unsigned find_get_entries(struct address_space *mapping,
if (xa_is_value(page))
goto export;
- if (!page_cache_get_speculative(page))
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
goto retry;
- /* Has the page moved or been split? */
+ /* The page was split under us? */
+ if (compound_head(page) != head)
+ goto put_page;
+
+ /* Has the page moved? */
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- page = find_subpage(page, xas.xa_index);
export:
indices[ret] = xas.xa_index;
@@ -1732,7 +1739,7 @@ export:
break;
continue;
put_page:
- put_page(page);
+ put_page(head);
retry:
xas_reset(&xas);
}
@@ -1774,27 +1781,33 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
rcu_read_lock();
xas_for_each(&xas, page, end) {
+ struct page *head;
if (xas_retry(&xas, page))
continue;
/* Skip over shadow, swap and DAX entries */
if (xa_is_value(page))
continue;
- if (!page_cache_get_speculative(page))
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
goto retry;
- /* Has the page moved or been split? */
+ /* The page was split under us? */
+ if (compound_head(page) != head)
+ goto put_page;
+
+ /* Has the page moved? */
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- pages[ret] = find_subpage(page, xas.xa_index);
+ pages[ret] = page;
if (++ret == nr_pages) {
*start = xas.xa_index + 1;
goto out;
}
continue;
put_page:
- put_page(page);
+ put_page(head);
retry:
xas_reset(&xas);
}
@@ -1839,6 +1852,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
rcu_read_lock();
for (page = xas_load(&xas); page; page = xas_next(&xas)) {
+ struct page *head;
if (xas_retry(&xas, page))
continue;
/*
@@ -1848,19 +1862,24 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
if (xa_is_value(page))
break;
- if (!page_cache_get_speculative(page))
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
goto retry;
- /* Has the page moved or been split? */
+ /* The page was split under us? */
+ if (compound_head(page) != head)
+ goto put_page;
+
+ /* Has the page moved? */
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- pages[ret] = find_subpage(page, xas.xa_index);
+ pages[ret] = page;
if (++ret == nr_pages)
break;
continue;
put_page:
- put_page(page);
+ put_page(head);
retry:
xas_reset(&xas);
}
@@ -1896,6 +1915,7 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
rcu_read_lock();
xas_for_each_marked(&xas, page, end, tag) {
+ struct page *head;
if (xas_retry(&xas, page))
continue;
/*
@@ -1906,21 +1926,26 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
if (xa_is_value(page))
continue;
- if (!page_cache_get_speculative(page))
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
goto retry;
- /* Has the page moved or been split? */
+ /* The page was split under us? */
+ if (compound_head(page) != head)
+ goto put_page;
+
+ /* Has the page moved? */
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- pages[ret] = find_subpage(page, xas.xa_index);
+ pages[ret] = page;
if (++ret == nr_pages) {
*index = xas.xa_index + 1;
goto out;
}
continue;
put_page:
- put_page(page);
+ put_page(head);
retry:
xas_reset(&xas);
}
@@ -2603,7 +2628,7 @@ void filemap_map_pages(struct vm_fault *vmf,
pgoff_t last_pgoff = start_pgoff;
unsigned long max_idx;
XA_STATE(xas, &mapping->i_pages, start_pgoff);
- struct page *page;
+ struct page *head, *page;
rcu_read_lock();
xas_for_each(&xas, page, end_pgoff) {
@@ -2612,19 +2637,24 @@ void filemap_map_pages(struct vm_fault *vmf,
if (xa_is_value(page))
goto next;
+ head = compound_head(page);
+
/*
* Check for a locked page first, as a speculative
* reference may adversely influence page migration.
*/
- if (PageLocked(page))
+ if (PageLocked(head))
goto next;
- if (!page_cache_get_speculative(page))
+ if (!page_cache_get_speculative(head))
goto next;
- /* Has the page moved or been split? */
+ /* The page was split under us? */
+ if (compound_head(page) != head)
+ goto skip;
+
+ /* Has the page moved? */
if (unlikely(page != xas_reload(&xas)))
goto skip;
- page = find_subpage(page, xas.xa_index);
if (!PageUptodate(page) ||
PageReadahead(page) ||
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 13:40:34 +0100