Commit 309f9bf3 authored by Daniel Gomez's avatar Daniel Gomez Committed by Euler
Browse files

mm: shmem: return number of pages beeing freed in shmem_free_swap 

mainline inclusion
from mainline-v6.12-rc1
commit 6ea0d1ccb110387244e04637f28a1d2eda54e3fb
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IAOMRL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6ea0d1ccb110387244e04637f28a1d2eda54e3fb

--------------------------------

Both shmem_free_swap callers expect the number of pages being freed.  In
the large folios context, this needs to support larger values other than 0
(used as 1 page being freed) and -ENOENT (used as 0 pages being freed).
In preparation for large folios adoption, make shmem_free_swap routine
return the number of pages being freed.  So, returning 0 in this context,
means 0 pages being freed.

While we are at it, changing to use free_swap_and_cache_nr() to free large
order swap entry by Baolin Wang.

Link: https://lkml.kernel.org/r/9623e863c83d749d5ab407f6fdf0a8e5a3bdf052.1723434324.git.baolin.wang@linux.alibaba.com


Signed-off-by: default avatarDaniel Gomez <da.gomez@samsung.com>
Signed-off-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: default avatarMatthew Wilcox <willy@infradead.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarWang Lian <dev01404@linx-info.com>
---
parent c77ad41c

mm/shmem.c

+16 −9
Original line number Diff line number Diff line
@@ -843,18 +843,22 @@ static void shmem_delete_from_page_cache(struct folio *folio, void *radswap) 
}



/*

 * Remove swap entry from page cache, free the swap and its page cache.

 * Remove swap entry from page cache, free the swap and its page cache. Returns

 * the number of pages being freed. 0 means entry not found in XArray (0 pages

 * being freed).

 */

static int shmem_free_swap(struct address_space *mapping,

static long shmem_free_swap(struct address_space *mapping,

			    pgoff_t index, void *radswap)

{

	int order = xa_get_order(&mapping->i_pages, index);

	void *old;



	old = xa_cmpxchg_irq(&mapping->i_pages, index, radswap, NULL, 0);

	if (old != radswap)

		return -ENOENT;

	free_swap_and_cache(radix_to_swp_entry(radswap));

		return 0;

	free_swap_and_cache_nr(radix_to_swp_entry(radswap), 1 << order);



	return 1 << order;

}



/*
@@ -1006,7 +1010,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, 
			if (xa_is_value(folio)) {

				if (unfalloc)

					continue;

				nr_swaps_freed += !shmem_free_swap(mapping,

				nr_swaps_freed += shmem_free_swap(mapping,

							indices[i], folio);

				continue;

			}
@@ -1073,14 +1077,17 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, 
			folio = fbatch.folios[i];



			if (xa_is_value(folio)) {

				long swaps_freed;



				if (unfalloc)

					continue;

				if (shmem_free_swap(mapping, indices[i], folio)) {

				swaps_freed = shmem_free_swap(mapping, indices[i], folio);

				if (!swaps_freed) {

					/* Swap was replaced by page: retry */

					index = indices[i];

					break;

				}

				nr_swaps_freed++;

				nr_swaps_freed += swaps_freed;

				continue;

			}