| Message ID | 20210126083402.142577-8-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: add read-only support for subpage sector size | expand |
On 1/26/21 3:33 AM, Qu Wenruo wrote: > There are locations where we allocate dummy extent buffers for temporary > usage, like in tree_mod_log_rewind() or get_old_root(). > > These dummy extent buffers will be handled by the same eb accessors, and > if they don't have page::private subpage eb accessors could fail. > > To address such problems, make __alloc_dummy_extent_buffer() attach > page private for dummy extent buffers too. > > Signed-off-by: Qu Wenruo <wqu@suse.com> > Reviewed-by: David Sterba <dsterba@suse.com> > Signed-off-by: David Sterba <dsterba@suse.com> Yup I'm slow, Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 118874926179..7ee28d94bae9 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5183,9 +5183,14 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, num_pages = num_extent_pages(eb); for (i = 0; i < num_pages; i++) { + int ret; + eb->pages[i] = alloc_page(GFP_NOFS); if (!eb->pages[i]) goto err; + ret = attach_extent_buffer_page(eb, eb->pages[i], NULL); + if (ret < 0) + goto err; } set_extent_buffer_uptodate(eb); btrfs_set_header_nritems(eb, 0); @@ -5193,8 +5198,10 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, return eb; err: - for (; i > 0; i--) + for (; i > 0; i--) { + detach_extent_buffer_page(eb, eb->pages[i - 1]); __free_page(eb->pages[i - 1]); + } __free_extent_buffer(eb); return NULL; }