| Message ID | 20200908075230.86856-11-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: add read-only support for subpage sector size | expand |
On 8.09.20 г. 10:52 ч., Qu Wenruo wrote: > When calling attach_extent_buffer_page(), either we're attaching > anonymous pages, called from btrfs_clone_extent_buffer(). > > Or we're attaching btree_inode pages, called from alloc_extent_buffer(). > > For the later case, we should have page->mapping->private_lock hold to > avoid race modifying page->private. > > Add assert_spin_locked() if we're calling from alloc_extent_buffer(). > > Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> but see one nit below. > --- > fs/btrfs/extent_io.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 1cb41dab7a1d..81e43d99feda 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -3096,6 +3096,9 @@ static int submit_extent_page(unsigned int opf, > static void attach_extent_buffer_page(struct extent_buffer *eb, > struct page *page) > { > + if (page->mapping) > + assert_spin_locked(&page->mapping->private_lock); nit: In addition to the changelog I'd rather have a comment explaining where the distinction we make : So something like: "Only pages allocated through alloc_extent_buffer will have their mapping set" > + > if (!PagePrivate(page)) > attach_page_private(page, eb); > else >
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 1cb41dab7a1d..81e43d99feda 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3096,6 +3096,9 @@ static int submit_extent_page(unsigned int opf, static void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page) { + if (page->mapping) + assert_spin_locked(&page->mapping->private_lock); + if (!PagePrivate(page)) attach_page_private(page, eb); else
When calling attach_extent_buffer_page(), either we're attaching anonymous pages, called from btrfs_clone_extent_buffer(). Or we're attaching btree_inode pages, called from alloc_extent_buffer(). For the later case, we should have page->mapping->private_lock hold to avoid race modifying page->private. Add assert_spin_locked() if we're calling from alloc_extent_buffer(). Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/extent_io.c | 3 +++ 1 file changed, 3 insertions(+)