| Message ID | 20230118094329.9553-9-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/9] mm: don't look at xarray value entries in split_huge_pages_in_file | expand |
On Wed, Jan 18, 2023 at 10:43:28AM +0100, Christoph Hellwig wrote: > filemap_get_folio can return NULL, skip those cases. Hmm, I'm not sure that's true. We have one place that calls extent_range_redirty_for_io(), and it previously calls extent_range_clear_dirty_for_io() which has an explicit BUG_ON(!page); /* Pages should be in the extent_io_tree */ so I'm going to say this one can't happen either. I haven't delved far enough into btrfs to figure out why it can't happen. > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/btrfs/extent_io.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index d55e4531ffd212..a54d2cf74ba020 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -230,6 +230,8 @@ void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end) > > while (index <= end_index) { > folio = filemap_get_folio(mapping, index); > + if (!folio) > + continue; > filemap_dirty_folio(mapping, folio); > folio_account_redirty(folio); > index += folio_nr_pages(folio); > -- > 2.39.0 >
On Wed, Jan 18, 2023 at 04:08:57PM +0000, Matthew Wilcox wrote: > On Wed, Jan 18, 2023 at 10:43:28AM +0100, Christoph Hellwig wrote: > > filemap_get_folio can return NULL, skip those cases. > > Hmm, I'm not sure that's true. We have one place that calls > extent_range_redirty_for_io(), and it previously calls > extent_range_clear_dirty_for_io() which has an explicit > > BUG_ON(!page); /* Pages should be in the extent_io_tree */ > > so I'm going to say this one can't happen either. I haven't delved far > enough into btrfs to figure out why it can't happen. I'll drop this patch for now.
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d55e4531ffd212..a54d2cf74ba020 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -230,6 +230,8 @@ void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end) while (index <= end_index) { folio = filemap_get_folio(mapping, index); + if (!folio) + continue; filemap_dirty_folio(mapping, folio); folio_account_redirty(folio); index += folio_nr_pages(folio);
filemap_get_folio can return NULL, skip those cases. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/btrfs/extent_io.c | 2 ++ 1 file changed, 2 insertions(+)