From: Theodore Ts'o Date: Thu, 28 Oct 2010 21:33:57 +0000 (-0400) Subject: ext4: BUG_ON fix: check if page has buffers before calling page_buffers() X-Git-Tag: v2.6.37-rc1~54^2 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=b1142e8fec6a594723e5054055a7b53379b90490;p=~emulex%2Finfiniband.git ext4: BUG_ON fix: check if page has buffers before calling page_buffers() We need to make check if a page does not have buffes by checking page_has_buffers(page) before calling page_buffers(page) in ext4_writepage(). Otherwise page_buffers() could throw a BUG_ON. Thanks also to Markus Trippelsdorf and Avinash Kurup who also reported the problem. Signed-off-by: "Theodore Ts'o" Reported-by: Sedat Dilek Tested-by: Sedat Dilek --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 2d6c6c8c036..19161647046 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2718,7 +2718,7 @@ static int ext4_writepage(struct page *page, * try to create them using __block_write_begin. If this * fails, redirty the page and move on. */ - if (!page_buffers(page)) { + if (!page_has_buffers(page)) { if (__block_write_begin(page, 0, len, noalloc_get_block_write)) { redirty_page: @@ -2732,12 +2732,10 @@ static int ext4_writepage(struct page *page, if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, ext4_bh_delay_or_unwritten)) { /* - * We don't want to do block allocation So redirty the - * page and return We may reach here when we do a - * journal commit via - * journal_submit_inode_data_buffers. If we don't - * have mapping block we just ignore them. We can also - * reach here via shrink_page_list + * We don't want to do block allocation, so redirty + * the page and return. We may reach here when we do + * a journal commit via journal_submit_inode_data_buffers. + * We can also reach here via shrink_page_list */ goto redirty_page; }