From: Josef Bacik Date: Fri, 4 May 2012 19:16:06 +0000 (-0400) Subject: Btrfs: fix page leak when allocing extent buffers X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=17de39ac17bf99b8bf0d819d13668d5048836efc;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git Btrfs: fix page leak when allocing extent buffers If we happen to alloc a extent buffer and then alloc a page and notice that page is already attached to an extent buffer, we will only unlock it and free our existing eb. Any pages currently attached to that eb will be properly freed, but we don't do the page_cache_release() on the page where we noticed the other extent buffer which can cause us to leak pages and I hope cause the weird issues we've been seeing in this area. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0c23e57077c6..2fb52c26c677 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4120,6 +4120,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, if (atomic_inc_not_zero(&exists->refs)) { spin_unlock(&mapping->private_lock); unlock_page(p); + page_cache_release(p); mark_extent_buffer_accessed(exists); goto free_eb; } @@ -4199,8 +4200,7 @@ free_eb: unlock_page(eb->pages[i]); } - if (!atomic_dec_and_test(&eb->refs)) - return exists; + WARN_ON(!atomic_dec_and_test(&eb->refs)); btrfs_release_extent_buffer(eb); return exists; }