* [PATCH v3 02/12] nilfs2: drop usage of page_index [not found] <20240429190500.30979-1-ryncsn@gmail.com> @ 2024-04-29 19:04 ` Kairui Song 2024-04-29 19:14 ` Matthew Wilcox 0 siblings, 1 reply; 7+ messages in thread From: Kairui Song @ 2024-04-29 19:04 UTC (permalink / raw) To: linux-mm Cc: Andrew Morton, Huang, Ying, Matthew Wilcox, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, Kairui Song, Ryusuke Konishi, linux-nilfs From: Kairui Song <kasong@tencent.com> page_index is only for mixed usage of page cache and swap cache, for pure page cache usage, the caller can just use page->index instead. It can't be a swap cache page here (being part of buffer head), so just drop it, also convert it to use folio. Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: linux-nilfs@vger.kernel.org --- fs/nilfs2/bmap.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c index 383f0afa2cea..f4e5df0cd720 100644 --- a/fs/nilfs2/bmap.c +++ b/fs/nilfs2/bmap.c @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, struct buffer_head *pbh; __u64 key; - key = page_index(bh->b_page) << (PAGE_SHIFT - - bmap->b_inode->i_blkbits); - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) key++; return key; -- 2.44.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 19:04 ` [PATCH v3 02/12] nilfs2: drop usage of page_index Kairui Song @ 2024-04-29 19:14 ` Matthew Wilcox 2024-04-29 19:22 ` Kairui Song 0 siblings, 1 reply; 7+ messages in thread From: Matthew Wilcox @ 2024-04-29 19:14 UTC (permalink / raw) To: Kairui Song Cc: linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, Ryusuke Konishi, linux-nilfs On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > From: Kairui Song <kasong@tencent.com> > > page_index is only for mixed usage of page cache and swap cache, for > pure page cache usage, the caller can just use page->index instead. > > It can't be a swap cache page here (being part of buffer head), > so just drop it, also convert it to use folio. > > Signed-off-by: Kairui Song <kasong@tencent.com> > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > Cc: linux-nilfs@vger.kernel.org > --- > fs/nilfs2/bmap.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > index 383f0afa2cea..f4e5df0cd720 100644 > --- a/fs/nilfs2/bmap.c > +++ b/fs/nilfs2/bmap.c > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > struct buffer_head *pbh; > __u64 key; > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > - bmap->b_inode->i_blkbits); > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > key++; > > return key; Why isn't this entire function simply: return bh->b_blocknr; ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 19:14 ` Matthew Wilcox @ 2024-04-29 19:22 ` Kairui Song 2024-04-29 19:28 ` Ryusuke Konishi 0 siblings, 1 reply; 7+ messages in thread From: Kairui Song @ 2024-04-29 19:22 UTC (permalink / raw) To: Matthew Wilcox Cc: linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, Ryusuke Konishi, linux-nilfs On Tue, Apr 30, 2024 at 3:14 AM Matthew Wilcox <willy@infradead.org> wrote: > > On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > > From: Kairui Song <kasong@tencent.com> > > > > page_index is only for mixed usage of page cache and swap cache, for > > pure page cache usage, the caller can just use page->index instead. > > > > It can't be a swap cache page here (being part of buffer head), > > so just drop it, also convert it to use folio. > > > > Signed-off-by: Kairui Song <kasong@tencent.com> > > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > > Cc: linux-nilfs@vger.kernel.org > > --- > > fs/nilfs2/bmap.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > > index 383f0afa2cea..f4e5df0cd720 100644 > > --- a/fs/nilfs2/bmap.c > > +++ b/fs/nilfs2/bmap.c > > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > > struct buffer_head *pbh; > > __u64 key; > > > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > > - bmap->b_inode->i_blkbits); > > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > > key++; > > > > return key; > > Why isn't this entire function simply: > > return bh->b_blocknr; > Nice idea, I didn't plan for extra clean up and test for fs code, but this might be OK to have, will check it. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 19:22 ` Kairui Song @ 2024-04-29 19:28 ` Ryusuke Konishi 2024-04-29 19:38 ` Matthew Wilcox 0 siblings, 1 reply; 7+ messages in thread From: Ryusuke Konishi @ 2024-04-29 19:28 UTC (permalink / raw) To: Kairui Song Cc: Matthew Wilcox, linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, linux-nilfs On Tue, Apr 30, 2024 at 4:22 AM Kairui Song <ryncsn@gmail.com> wrote: > > On Tue, Apr 30, 2024 at 3:14 AM Matthew Wilcox <willy@infradead.org> wrote: > > > > On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > > > From: Kairui Song <kasong@tencent.com> > > > > > > page_index is only for mixed usage of page cache and swap cache, for > > > pure page cache usage, the caller can just use page->index instead. > > > > > > It can't be a swap cache page here (being part of buffer head), > > > so just drop it, also convert it to use folio. > > > > > > Signed-off-by: Kairui Song <kasong@tencent.com> > > > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > > > Cc: linux-nilfs@vger.kernel.org > > > --- > > > fs/nilfs2/bmap.c | 5 ++--- > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > > > index 383f0afa2cea..f4e5df0cd720 100644 > > > --- a/fs/nilfs2/bmap.c > > > +++ b/fs/nilfs2/bmap.c > > > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > > > struct buffer_head *pbh; > > > __u64 key; > > > > > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > > > - bmap->b_inode->i_blkbits); > > > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > > > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > > > key++; > > > > > > return key; > > > > Why isn't this entire function simply: > > > > return bh->b_blocknr; > > > > Nice idea, I didn't plan for extra clean up and test for fs code, but > this might be OK to have, will check it. Wait a minute. This function returns a key that corresponds to the cache offset of the data block, not the disk block number. Why is returning to bh->b_blocknr an alternative ? Am I missing something? Ryusuke Konishi ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 19:28 ` Ryusuke Konishi @ 2024-04-29 19:38 ` Matthew Wilcox 2024-04-29 20:01 ` Ryusuke Konishi 0 siblings, 1 reply; 7+ messages in thread From: Matthew Wilcox @ 2024-04-29 19:38 UTC (permalink / raw) To: Ryusuke Konishi Cc: Kairui Song, linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, linux-nilfs On Tue, Apr 30, 2024 at 04:28:41AM +0900, Ryusuke Konishi wrote: > On Tue, Apr 30, 2024 at 4:22 AM Kairui Song <ryncsn@gmail.com> wrote: > > > > On Tue, Apr 30, 2024 at 3:14 AM Matthew Wilcox <willy@infradead.org> wrote: > > > > > > On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > > > > From: Kairui Song <kasong@tencent.com> > > > > > > > > page_index is only for mixed usage of page cache and swap cache, for > > > > pure page cache usage, the caller can just use page->index instead. > > > > > > > > It can't be a swap cache page here (being part of buffer head), > > > > so just drop it, also convert it to use folio. > > > > > > > > Signed-off-by: Kairui Song <kasong@tencent.com> > > > > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > > > > Cc: linux-nilfs@vger.kernel.org > > > > --- > > > > fs/nilfs2/bmap.c | 5 ++--- > > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > > > > index 383f0afa2cea..f4e5df0cd720 100644 > > > > --- a/fs/nilfs2/bmap.c > > > > +++ b/fs/nilfs2/bmap.c > > > > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > > > > struct buffer_head *pbh; > > > > __u64 key; > > > > > > > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > > > > - bmap->b_inode->i_blkbits); > > > > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > > > > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > > > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > > > > key++; > > > > > > > > return key; > > > > > > Why isn't this entire function simply: > > > > > > return bh->b_blocknr; > > > > > > > Nice idea, I didn't plan for extra clean up and test for fs code, but > > this might be OK to have, will check it. > > Wait a minute. > > This function returns a key that corresponds to the cache offset of > the data block, not the disk block number. > > Why is returning to bh->b_blocknr an alternative ? > Am I missing something? Sorry, I forgot how b_blocknr was used. What I meant was: u64 key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); return key + bh_offset(bh) >> bmap->b_inode->i_blkbits; The point is to get rid of the loop. We could simplify this (and make it ready for bs>PS) by doing: loff_t pos = folio_pos(bh->b_folio) + bh_offset(bh); return pos >> bmap->b_inode->i_blkbits; ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 19:38 ` Matthew Wilcox @ 2024-04-29 20:01 ` Ryusuke Konishi 2024-04-30 15:27 ` Kairui Song 0 siblings, 1 reply; 7+ messages in thread From: Ryusuke Konishi @ 2024-04-29 20:01 UTC (permalink / raw) To: Matthew Wilcox, Kairui Song Cc: linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, linux-nilfs On Tue, Apr 30, 2024 at 4:38 AM Matthew Wilcox wrote: > > On Tue, Apr 30, 2024 at 04:28:41AM +0900, Ryusuke Konishi wrote: > > On Tue, Apr 30, 2024 at 4:22 AM Kairui Song <ryncsn@gmail.com> wrote: > > > > > > On Tue, Apr 30, 2024 at 3:14 AM Matthew Wilcox <willy@infradead.org> wrote: > > > > > > > > On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > > > > > From: Kairui Song <kasong@tencent.com> > > > > > > > > > > page_index is only for mixed usage of page cache and swap cache, for > > > > > pure page cache usage, the caller can just use page->index instead. > > > > > > > > > > It can't be a swap cache page here (being part of buffer head), > > > > > so just drop it, also convert it to use folio. > > > > > > > > > > Signed-off-by: Kairui Song <kasong@tencent.com> > > > > > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > > > > > Cc: linux-nilfs@vger.kernel.org > > > > > --- > > > > > fs/nilfs2/bmap.c | 5 ++--- > > > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > > > > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > > > > > index 383f0afa2cea..f4e5df0cd720 100644 > > > > > --- a/fs/nilfs2/bmap.c > > > > > +++ b/fs/nilfs2/bmap.c > > > > > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > > > > > struct buffer_head *pbh; > > > > > __u64 key; > > > > > > > > > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > > > > > - bmap->b_inode->i_blkbits); > > > > > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > > > > > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > > > > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > > > > > key++; > > > > > > > > > > return key; > > > > > > > > Why isn't this entire function simply: > > > > > > > > return bh->b_blocknr; > > > > > > > > > > Nice idea, I didn't plan for extra clean up and test for fs code, but > > > this might be OK to have, will check it. > > > > Wait a minute. > > > > This function returns a key that corresponds to the cache offset of > > the data block, not the disk block number. > > > > Why is returning to bh->b_blocknr an alternative ? > > Am I missing something? > > Sorry, I forgot how b_blocknr was used. What I meant was: > > u64 key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > return key + bh_offset(bh) >> bmap->b_inode->i_blkbits; > > The point is to get rid of the loop. We could simplify this (and make > it ready for bs>PS) by doing: > > loff_t pos = folio_pos(bh->b_folio) + bh_offset(bh); > return pos >> bmap->b_inode->i_blkbits; I see, I understand the idea that it would be better to eliminate the loop. The above conversion looks fine. What are you going to do, Kairui ? Thanks, Ryusuke Konishi ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 02/12] nilfs2: drop usage of page_index 2024-04-29 20:01 ` Ryusuke Konishi @ 2024-04-30 15:27 ` Kairui Song 0 siblings, 0 replies; 7+ messages in thread From: Kairui Song @ 2024-04-30 15:27 UTC (permalink / raw) To: Ryusuke Konishi Cc: Matthew Wilcox, linux-mm, Andrew Morton, Huang, Ying, Chris Li, Barry Song, Ryan Roberts, Neil Brown, Minchan Kim, Hugh Dickins, David Hildenbrand, Yosry Ahmed, linux-fsdevel, linux-kernel, linux-nilfs On Tue, Apr 30, 2024 at 4:01 AM Ryusuke Konishi <konishi.ryusuke@gmail.com> wrote: > > On Tue, Apr 30, 2024 at 4:38 AM Matthew Wilcox wrote: > > > > On Tue, Apr 30, 2024 at 04:28:41AM +0900, Ryusuke Konishi wrote: > > > On Tue, Apr 30, 2024 at 4:22 AM Kairui Song <ryncsn@gmail.com> wrote: > > > > > > > > On Tue, Apr 30, 2024 at 3:14 AM Matthew Wilcox <willy@infradead.org> wrote: > > > > > > > > > > On Tue, Apr 30, 2024 at 03:04:50AM +0800, Kairui Song wrote: > > > > > > From: Kairui Song <kasong@tencent.com> > > > > > > > > > > > > page_index is only for mixed usage of page cache and swap cache, for > > > > > > pure page cache usage, the caller can just use page->index instead. > > > > > > > > > > > > It can't be a swap cache page here (being part of buffer head), > > > > > > so just drop it, also convert it to use folio. > > > > > > > > > > > > Signed-off-by: Kairui Song <kasong@tencent.com> > > > > > > Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> > > > > > > Cc: linux-nilfs@vger.kernel.org > > > > > > --- > > > > > > fs/nilfs2/bmap.c | 5 ++--- > > > > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > > > > > > > diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c > > > > > > index 383f0afa2cea..f4e5df0cd720 100644 > > > > > > --- a/fs/nilfs2/bmap.c > > > > > > +++ b/fs/nilfs2/bmap.c > > > > > > @@ -453,9 +453,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap, > > > > > > struct buffer_head *pbh; > > > > > > __u64 key; > > > > > > > > > > > > - key = page_index(bh->b_page) << (PAGE_SHIFT - > > > > > > - bmap->b_inode->i_blkbits); > > > > > > - for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page) > > > > > > + key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > > > > > + for (pbh = folio_buffers(bh->b_folio); pbh != bh; pbh = pbh->b_this_page) > > > > > > key++; > > > > > > > > > > > > return key; > > > > > > > > > > Why isn't this entire function simply: > > > > > > > > > > return bh->b_blocknr; > > > > > > > > > > > > > Nice idea, I didn't plan for extra clean up and test for fs code, but > > > > this might be OK to have, will check it. > > > > > > Wait a minute. > > > > > > This function returns a key that corresponds to the cache offset of > > > the data block, not the disk block number. > > > > > > Why is returning to bh->b_blocknr an alternative ? > > > Am I missing something? > > > > Sorry, I forgot how b_blocknr was used. What I meant was: > > > > u64 key = bh->b_folio->index << (PAGE_SHIFT - bmap->b_inode->i_blkbits); > > > > return key + bh_offset(bh) >> bmap->b_inode->i_blkbits; > > > > The point is to get rid of the loop. We could simplify this (and make > > it ready for bs>PS) by doing: > > > > loff_t pos = folio_pos(bh->b_folio) + bh_offset(bh); > > return pos >> bmap->b_inode->i_blkbits; > > I see, I understand the idea that it would be better to eliminate the loop. > > The above conversion looks fine. > What are you going to do, Kairui ? Hi, I'd like to remove the loop as Matthew suggested, that will make the code cleaner. I'm not very familiar with this part so I'll check related code first for double check, won't take long though. > Thanks, > Ryusuke Konishi ^ permalink raw reply [flat|nested] 7+ messages in thread
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[not found] <20240429190500.30979-1-ryncsn@gmail.com>
2024-04-29 19:04 ` [PATCH v3 02/12] nilfs2: drop usage of page_index Kairui Song
2024-04-29 19:14 ` Matthew Wilcox
2024-04-29 19:22 ` Kairui Song
2024-04-29 19:28 ` Ryusuke Konishi
2024-04-29 19:38 ` Matthew Wilcox
2024-04-29 20:01 ` Ryusuke Konishi
2024-04-30 15:27 ` Kairui Song
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