| Message ID | 20250226-20250221-warning-in-shmem_writepage-v1-1-5ad19420e17e@igalia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: shmem: remove unnecessary warning in shmem_writepage() | expand |
On 2025/2/26 20:26, Ricardo Cañuelo Navarro wrote: > Although the scenario where shmem_writepage() is called with info->flags > & VM_LOCKED is unlikely to happen, it's still possible, as evidenced by > syzbot [1]. However, the warning in this case isn't necessary because > the situation is already handled correctly [2]. > > [2] https://lore.kernel.org/lkml/8afe1f7f-31a2-4fc0-1fbd-f9ba8a116fe3@google.com/ > > Reported-by: Pengfei Xu <pengfei.xu@intel.com> > Closes: https://lore.kernel.org/lkml/ZZ9PShXjKJkVelNm@xpf.sh.intel.com/ [1] > Suggested-by: Hugh Dickins <hughd@google.com> > Cc: Florent Revest <revest@chromium.org> > Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com> > Fixes: 9a976f0c847b ("shmem: skip page split if we're not reclaiming") > --- LGTM. Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> > mm/shmem.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 4ea6109a80431e5eeae15278064d5c86412f9fc9..a5eaad03038e8ca56a54d096159892e01c7a5bfe 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1548,7 +1548,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) > if (WARN_ON_ONCE(!wbc->for_reclaim)) > goto redirty; > > - if (WARN_ON_ONCE((info->flags & VM_LOCKED) || sbinfo->noswap)) > + if ((info->flags & VM_LOCKED) || sbinfo->noswap) > goto redirty; > > if (!total_swap_pages) > > --- > base-commit: ac9c34d1e45a4c25174ced4fc0cfc33ff3ed08c7 > change-id: 20250226-20250221-warning-in-shmem_writepage-e7f8f273317c > > Cheers, > Ricardo >
diff --git a/mm/shmem.c b/mm/shmem.c index 4ea6109a80431e5eeae15278064d5c86412f9fc9..a5eaad03038e8ca56a54d096159892e01c7a5bfe 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1548,7 +1548,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) if (WARN_ON_ONCE(!wbc->for_reclaim)) goto redirty; - if (WARN_ON_ONCE((info->flags & VM_LOCKED) || sbinfo->noswap)) + if ((info->flags & VM_LOCKED) || sbinfo->noswap) goto redirty; if (!total_swap_pages)
Although the scenario where shmem_writepage() is called with info->flags & VM_LOCKED is unlikely to happen, it's still possible, as evidenced by syzbot [1]. However, the warning in this case isn't necessary because the situation is already handled correctly [2]. [2] https://lore.kernel.org/lkml/8afe1f7f-31a2-4fc0-1fbd-f9ba8a116fe3@google.com/ Reported-by: Pengfei Xu <pengfei.xu@intel.com> Closes: https://lore.kernel.org/lkml/ZZ9PShXjKJkVelNm@xpf.sh.intel.com/ [1] Suggested-by: Hugh Dickins <hughd@google.com> Cc: Florent Revest <revest@chromium.org> Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com> Fixes: 9a976f0c847b ("shmem: skip page split if we're not reclaiming") --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: ac9c34d1e45a4c25174ced4fc0cfc33ff3ed08c7 change-id: 20250226-20250221-warning-in-shmem_writepage-e7f8f273317c Cheers, Ricardo