On Mon, Jul 11, 2016 at 10:39:07AM -0700, Liu Bo wrote:
> eb->io_pages is set in read_extent_buffer_pages().
>
> In case of readpage failure, for pages that have been added to bio,
> it calls bio_endio and later readpage_io_failed_hook() does the work.
>
> When this eb's page (couldn't be the 1st page) fails to add itself to bio
> due to failure in merge_bio(), it cannot decrease eb->io_pages via bio_endio,
> and ends up with a memory leak eventually.
>
> This lets __do_readpage propagate errors to callers and adds the
> 'atomic_dec(&eb->io_pages)'.
>
> Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
> if (!PageUptodate(page)) {
> + if (ret) {
> + atomic_dec(&eb->io_pages);
> + unlock_page(page);
> + continue;
> + }
This changes the behaviour to "fail early", which could be positive as a
sequence of unreadable blocks will not try to reread all of them with
the timeouts and retries.
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