| Message ID | cover.1743493507.git.wqu@suse.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | btrfs: two small and safe fixes for large folios | expand |
On Tue, Apr 01, 2025 at 06:20:27PM +1030, Qu Wenruo wrote: > [CHANGELOG] > v2: > - Fix a bug that page_pgoff() usage lacks left page shift > > Two small and simple fixes. > > The first one is that with large folios, we can have order 6 folios which > reached our current BITS_PER_LONG limit, triggering a previously > impossible ASSERT(), which is based on the fact that our largest page > size (64K) can not reach BITS_PER_LONG blocks per page. > > An easily fix by extending the ASSERT() condition to cover > blocks_per_folio == BITS_PER_LONG cases. > > The second one is a little more complex, that with large folios, if we > still go through the single page bio vec iteration, we can not call > page_offset(), as non-head pages of a large folio do not have their > page::index initialized properly. > > Fix that by going a helper using page_pgoff() to calculate the file > offset, which handles both head and non-head pages of a large folio. LGTM, thanks. Reviewed-by: Boris Burkov <boris@bur.io> > > Qu Wenruo (2): > btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP() > btrfs: fix the file offset calculation inside > btrfs_decompress_buf2page() > > fs/btrfs/compression.c | 18 +++++++++++++++++- > fs/btrfs/subpage.c | 2 +- > 2 files changed, 18 insertions(+), 2 deletions(-) > > -- > 2.49.0 >
On 4/1/25 3:50 AM, Qu Wenruo wrote: > [CHANGELOG] > v2: > - Fix a bug that page_pgoff() usage lacks left page shift > > Two small and simple fixes. > > The first one is that with large folios, we can have order 6 folios which > reached our current BITS_PER_LONG limit, triggering a previously > impossible ASSERT(), which is based on the fact that our largest page > size (64K) can not reach BITS_PER_LONG blocks per page. > > An easily fix by extending the ASSERT() condition to cover > blocks_per_folio == BITS_PER_LONG cases. > > The second one is a little more complex, that with large folios, if we > still go through the single page bio vec iteration, we can not call > page_offset(), as non-head pages of a large folio do not have their > page::index initialized properly. > > Fix that by going a helper using page_pgoff() to calculate the file > offset, which handles both head and non-head pages of a large folio. > > Qu Wenruo (2): > btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP() > btrfs: fix the file offset calculation inside > btrfs_decompress_buf2page() > > fs/btrfs/compression.c | 18 +++++++++++++++++- > fs/btrfs/subpage.c | 2 +- > 2 files changed, 18 insertions(+), 2 deletions(-) > Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
[CHANGELOG] v2: - Fix a bug that page_pgoff() usage lacks left page shift Two small and simple fixes. The first one is that with large folios, we can have order 6 folios which reached our current BITS_PER_LONG limit, triggering a previously impossible ASSERT(), which is based on the fact that our largest page size (64K) can not reach BITS_PER_LONG blocks per page. An easily fix by extending the ASSERT() condition to cover blocks_per_folio == BITS_PER_LONG cases. The second one is a little more complex, that with large folios, if we still go through the single page bio vec iteration, we can not call page_offset(), as non-head pages of a large folio do not have their page::index initialized properly. Fix that by going a helper using page_pgoff() to calculate the file offset, which handles both head and non-head pages of a large folio. Qu Wenruo (2): btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP() btrfs: fix the file offset calculation inside btrfs_decompress_buf2page() fs/btrfs/compression.c | 18 +++++++++++++++++- fs/btrfs/subpage.c | 2 +- 2 files changed, 18 insertions(+), 2 deletions(-)