diff mbox series

[02/10] udf: Convert in-ICB files to use udf_writepages()

Message ID 20230124120628.24449-2-jack@suse.cz (mailing list archive)
State New, archived
Headers show
Series udf: Unify aops | expand

Commit Message

Jan Kara Jan. 24, 2023, 12:06 p.m. UTC 
Switching address_space_operations while a file is used is difficult to
do in a race-free way. To be able to use single address_space_operations
in UDF, make in-ICB files use udf_writepages().

Reported-by: syzbot+c27475eb921c46bbdc62@syzkaller.appspotmail.com
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/file.c    | 21 +--------------------
 fs/udf/inode.c   | 29 ++++++++++++++++++++++++++---
 fs/udf/udfdecl.h |  1 +
 3 files changed, 28 insertions(+), 23 deletions(-)

Comments

Christoph Hellwig Jan. 24, 2023, 1:25 p.m. UTC | #1 
As a pure mechanical move this looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

But some comments:

> +	struct inode *inode = page->mapping->host;
> +	char *kaddr;
> +	struct udf_inode_info *iinfo = UDF_I(inode);
> +
> +	BUG_ON(!PageLocked(page));
> +
> +	kaddr = kmap_atomic(page);
> +	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
> +	SetPageUptodate(page);
> +	kunmap_atomic(kaddr);
> +	unlock_page(page);

This really should be using memcpy_to_page.  And the SetPageUptodate
here in ->writepages loos a little odd as well.
Jan Kara Jan. 25, 2023, 9:28 a.m. UTC | #2 
On Tue 24-01-23 05:25:09, Christoph Hellwig wrote:
> As a pure mechanical move this looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks!

> But some comments:
> 
> > +	struct inode *inode = page->mapping->host;
> > +	char *kaddr;
> > +	struct udf_inode_info *iinfo = UDF_I(inode);
> > +
> > +	BUG_ON(!PageLocked(page));
> > +
> > +	kaddr = kmap_atomic(page);
> > +	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
> > +	SetPageUptodate(page);
> > +	kunmap_atomic(kaddr);
> > +	unlock_page(page);
> 
> This really should be using memcpy_to_page.  And the SetPageUptodate
> here in ->writepages loos a little odd as well.

Good points. Added a cleanup patch for this. And then one more to get rid
of the last remaining kmap_atomic() use in UDF (BTW that would benefit from
memcpy_to_page_page() helper as well).

								Honza
diff mbox series

Patch

diff --git a/fs/udf/file.c b/fs/udf/file.c
index 2666234a5204..7a8dbad86e41 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -57,25 +57,6 @@  void udf_adinicb_readpage(struct page *page)
 	kunmap_atomic(kaddr);
 }
 
-static int udf_adinicb_writepage(struct page *page,
-				 struct writeback_control *wbc)
-{
-	struct inode *inode = page->mapping->host;
-	char *kaddr;
-	struct udf_inode_info *iinfo = UDF_I(inode);
-
-	BUG_ON(!PageLocked(page));
-
-	kaddr = kmap_atomic(page);
-	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
-	SetPageUptodate(page);
-	kunmap_atomic(kaddr);
-	mark_inode_dirty(inode);
-	unlock_page(page);
-
-	return 0;
-}
-
 static int udf_adinicb_write_begin(struct file *file,
 			struct address_space *mapping, loff_t pos,
 			unsigned len, struct page **pagep,
@@ -119,7 +100,7 @@  const struct address_space_operations udf_adinicb_aops = {
 	.dirty_folio	= block_dirty_folio,
 	.invalidate_folio = block_invalidate_folio,
 	.read_folio	= udf_read_folio,
-	.writepage	= udf_adinicb_writepage,
+	.writepages	= udf_writepages,
 	.write_begin	= udf_adinicb_write_begin,
 	.write_end	= udf_adinicb_write_end,
 	.direct_IO	= udf_adinicb_direct_IO,
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 9ef56574e452..54e6127ebf55 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -185,10 +185,33 @@  static void udf_write_failed(struct address_space *mapping, loff_t to)
 	}
 }
 
-static int udf_writepages(struct address_space *mapping,
-			struct writeback_control *wbc)
+static int udf_adinicb_writepage(struct page *page,
+				 struct writeback_control *wbc, void *data)
 {
-	return mpage_writepages(mapping, wbc, udf_get_block_wb);
+	struct inode *inode = page->mapping->host;
+	char *kaddr;
+	struct udf_inode_info *iinfo = UDF_I(inode);
+
+	BUG_ON(!PageLocked(page));
+
+	kaddr = kmap_atomic(page);
+	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
+	SetPageUptodate(page);
+	kunmap_atomic(kaddr);
+	unlock_page(page);
+	mark_inode_dirty(inode);
+
+	return 0;
+}
+
+int udf_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+	struct inode *inode = mapping->host;
+	struct udf_inode_info *iinfo = UDF_I(inode);
+
+	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB)
+		return mpage_writepages(mapping, wbc, udf_get_block_wb);
+	return write_cache_pages(mapping, wbc, udf_adinicb_writepage, NULL);
 }
 
 int udf_read_folio(struct file *file, struct folio *folio)
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index 6b93b393cb46..48647eab26a6 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -160,6 +160,7 @@  extern int udf_setsize(struct inode *, loff_t);
 extern void udf_evict_inode(struct inode *);
 extern int udf_write_inode(struct inode *, struct writeback_control *wbc);
 int udf_read_folio(struct file *file, struct folio *folio);
+int udf_writepages(struct address_space *mapping, struct writeback_control *wbc);
 extern int8_t inode_bmap(struct inode *, sector_t, struct extent_position *,
 			 struct kernel_lb_addr *, uint32_t *, sector_t *);
 int udf_get_block(struct inode *, sector_t, struct buffer_head *, int);