From af223eac15f659880c341bd8eab02da9821357c6 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 13 Jun 2017 16:20:25 +0200 Subject: [PATCH] udf: Fix deadlock between writeback and udf_setsize() udf_setsize() called truncate_setsize() with i_data_sem held. Thus truncate_pagecache() called from truncate_setsize() could lock a page under i_data_sem which can deadlock as page lock ranks below i_data_sem - e. g. writeback can hold page lock and try to acquire i_data_sem to map a block. Fix the problem by moving truncate_setsize() calls from under i_data_sem. It is safe for us to change i_size without holding i_data_sem as all the places that depend on i_size being stable already hold inode_lock. CC: stable@vger.kernel.org Fixes: 9788aff34d251e8231eca25f7dd79cfaa45d50d1 Signed-off-by: Jan Kara --- fs/udf/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 98c510e172032..18fdb9d90812a 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1222,8 +1222,8 @@ int udf_setsize(struct inode *inode, loff_t newsize) return err; } set_size: - truncate_setsize(inode, newsize); up_write(&iinfo->i_data_sem); + truncate_setsize(inode, newsize); } else { if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { down_write(&iinfo->i_data_sem); @@ -1240,9 +1240,9 @@ set_size: udf_get_block); if (err) return err; + truncate_setsize(inode, newsize); down_write(&iinfo->i_data_sem); udf_clear_extent_cache(inode); - truncate_setsize(inode, newsize); udf_truncate_extents(inode); up_write(&iinfo->i_data_sem); } -- 2.39.5