Messages in this thread Patch in this message | | | From | Huang Ying <> | Subject | [PATCH -V2 4/5] swap: remove get/put_swap_device() in __swap_duplicate() | Date | Mon, 22 May 2023 15:09:04 +0800 |
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__swap_duplicate() is called by
- swap_shmem_alloc(): the page lock of the swap cache is held.
- copy_nonpresent_pte() -> swap_duplicate() and try_to_unmap_one() -> swap_duplicate(): the page table lock is held.
- __read_swap_cache_async() -> swapcache_prepare(): enclosed with get/put_swap_device() in __read_swap_cache_async() already.
So, it's safe to remove get/put_swap_device() in __swap_duplicate().
Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> --- mm/swapfile.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c index e9cce775fb25..4dbaea64635d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3264,9 +3264,7 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage) unsigned char has_cache; int err; - p = get_swap_device(entry); - if (!p) - return -EINVAL; + p = swp_swap_info(entry); offset = swp_offset(entry); ci = lock_cluster_or_swap_info(p, offset); @@ -3313,7 +3311,6 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage) unlock_out: unlock_cluster_or_swap_info(p, ci); - put_swap_device(p); return err; } -- 2.39.2
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