| Message ID | 20210810202936.2672-2-shy828301@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3,linux-next] Revert "mm,shmem: fix a typo in shmem_swapin_page()" | expand |
On Tue, Aug 10, 2021 at 1:29 PM Yang Shi <shy828301@gmail.com> wrote: > > 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. The updated commit log per the discussion with Hugh: 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/ > > Suggested-by: Hugh Dickins <hughd@google.com> > Cc: "Huang, Ying" <ying.huang@intel.com> > Cc: Miaohe Lin <linmiaohe@huawei.com> > Signed-off-by: Yang Shi <shy828301@gmail.com> > --- > mm/shmem.c | 14 +------------- > 1 file changed, 1 insertion(+), 13 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index dcc07d14162e..d5427de5bf02 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1699,8 +1699,7 @@ 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; > > @@ -1708,12 +1707,6 @@ 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) { > @@ -1775,8 +1768,6 @@ 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)) > @@ -1787,9 +1778,6 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, > put_page(page); > } > > - if (si) > - put_swap_device(si); > - > return error; > } > > -- > 2.26.2 >
diff --git a/mm/shmem.c b/mm/shmem.c index dcc07d14162e..d5427de5bf02 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1699,8 +1699,7 @@ 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; @@ -1708,12 +1707,6 @@ 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) { @@ -1775,8 +1768,6 @@ 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)) @@ -1787,9 +1778,6 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, put_page(page); } - if (si) - put_swap_device(si); - return error; }
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. Suggested-by: Hugh Dickins <hughd@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Yang Shi <shy828301@gmail.com> --- mm/shmem.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-)