Re: [PATCH v14 101/138] iomap: Convert iomap_page_mkwrite to use a folio
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-07-15 21:41:08
Also in:
linux-fsdevel, linux-mm
On Thu, Jul 15, 2021 at 04:36:27AM +0100, Matthew Wilcox (Oracle) wrote:
quoted hunk ↗ jump to hunk
If we write to any page in a folio, we have to mark the entire folio as dirty, and potentially COW the entire folio, because it'll all get written back as one unit. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/iomap/buffered-io.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-)diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 7c702d6c2f64..a3fe0d36c739 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c@@ -951,23 +951,23 @@ iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, } EXPORT_SYMBOL_GPL(iomap_truncate_page); -static loff_t -iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length, - void *data, struct iomap *iomap, struct iomap *srcmap) +static loff_t iomap_folio_mkwrite_actor(struct inode *inode, loff_t pos, + loff_t length, void *data, struct iomap *iomap, + struct iomap *srcmap) { - struct page *page = data; - struct folio *folio = page_folio(page); + struct folio *folio = data; int ret; if (iomap->flags & IOMAP_F_BUFFER_HEAD) { - ret = __block_write_begin_int(page, pos, length, NULL, iomap); + ret = __block_write_begin_int(&folio->page, pos, length, NULL, + iomap); if (ret) return ret; - block_commit_write(page, 0, length); + block_commit_write(&folio->page, 0, length); } else { - WARN_ON_ONCE(!PageUptodate(page)); + WARN_ON_ONCE(!folio_test_uptodate(folio)); iomap_page_create(inode, folio); - set_page_dirty(page); + folio_mark_dirty(folio); } return length;@@ -975,33 +975,33 @@ iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length, vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops) { - struct page *page = vmf->page; + struct folio *folio = page_folio(vmf->page);
If before the page fault the folio was a compound 2M page, will the memory manager will have split it into 4k pages before passing it to us? That's a roundabout way of asking if we should expect folio_mkwrite at some point. ;) The conversion looks pretty straightforward though. Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
struct inode *inode = file_inode(vmf->vma->vm_file);
- unsigned long length;
- loff_t offset;
+ size_t length;
+ loff_t pos;
ssize_t ret;
- lock_page(page);
- ret = page_mkwrite_check_truncate(page, inode);
+ folio_lock(folio);
+ ret = folio_mkwrite_check_truncate(folio, inode);
if (ret < 0)
goto out_unlock;
length = ret;
- offset = page_offset(page);
+ pos = folio_pos(folio);
while (length > 0) {
- ret = iomap_apply(inode, offset, length,
- IOMAP_WRITE | IOMAP_FAULT, ops, page,
- iomap_page_mkwrite_actor);
+ ret = iomap_apply(inode, pos, length,
+ IOMAP_WRITE | IOMAP_FAULT, ops, folio,
+ iomap_folio_mkwrite_actor);
if (unlikely(ret <= 0))
goto out_unlock;
- offset += ret;
+ pos += ret;
length -= ret;
}
- wait_for_stable_page(page);
+ folio_wait_stable(folio);
return VM_FAULT_LOCKED;
out_unlock:
- unlock_page(page);
+ folio_unlock(folio);
return block_page_mkwrite_return(ret);
}
EXPORT_SYMBOL_GPL(iomap_page_mkwrite);
--
2.30.2