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authorYang Shi <shy828301@gmail.com>2021-08-20 05:04:05 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-08-20 21:31:41 +0300
commitb1e1ef345433fb03742003677ddfb980d148092b (patch)
tree56e6fc8cd545758a03a749433d6cd3b07ff518d4 /mm/shmem.c
parent614cb2751d3150850d459bee596c397f344a7936 (diff)
downloadlinux-b1e1ef345433fb03742003677ddfb980d148092b.tar.xz
Revert "mm/shmem: fix shmem_swapin() race with swapoff"
Due to the change about how block layer detects congestion the justification of commit 8fd2e0b505d1 ("mm: swap: check if swap backing device is congested or not") doesn't stand anymore, so the commit could be just reverted in order to solve the race reported by commit 2efa33fc7f6e ("mm/shmem: fix shmem_swapin() race with swapoff"), so the fix commit could be just reverted as well. And that fix is also kind of buggy as discussed by [1] and [2]. [1] https://lore.kernel.org/linux-mm/24187e5e-069-9f3f-cefe-39ac70783753@google.com/ [2] https://lore.kernel.org/linux-mm/e82380b9-3ad4-4a52-be50-6d45c7f2b5da@google.com/ Link: https://lkml.kernel.org/r/20210810202936.2672-2-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c14
1 files changed, 1 insertions, 13 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 70d9ce294bb4..dacda7463d54 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1696,8 +1696,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index,
struct address_space *mapping = inode->i_mapping;
struct shmem_inode_info *info = SHMEM_I(inode);
struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL;
- struct swap_info_struct *si;
- struct page *page = NULL;
+ struct page *page;
swp_entry_t swap;
int error;
@@ -1705,12 +1704,6 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index,
swap = radix_to_swp_entry(*pagep);
*pagep = NULL;
- /* Prevent swapoff from happening to us. */
- si = get_swap_device(swap);
- if (!si) {
- error = EINVAL;
- goto failed;
- }
/* Look it up and read it in.. */
page = lookup_swap_cache(swap, NULL, 0);
if (!page) {
@@ -1772,8 +1765,6 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index,
swap_free(swap);
*pagep = page;
- if (si)
- put_swap_device(si);
return 0;
failed:
if (!shmem_confirm_swap(mapping, index, swap))
@@ -1784,9 +1775,6 @@ unlock:
put_page(page);
}
- if (si)
- put_swap_device(si);
-
return error;
}