From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: [PATCH 2/2] f2fs: fix a deadlock for summary page lock vs. sentry_lock Date: Fri, 29 May 2015 11:04:38 -0700 Message-ID: <1432922678-22578-2-git-send-email-jaegeuk@kernel.org> References: <1432922678-22578-1-git-send-email-jaegeuk@kernel.org> Return-path: In-Reply-To: <1432922678-22578-1-git-send-email-jaegeuk@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim List-Id: linux-f2fs-devel.lists.sourceforge.net In f2fs_gc: In f2fs_replace_block: - lock_page(sum_page) - check_valid_map() - mutex_lock(sentry_lock) - mutex_lock(sentry_lock) - change_curseg() - lock_page(sum_page) This patch fixes the deadlock condition. Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 43354cb..e1e7361 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -750,6 +750,15 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, sum = page_address(sum_page); + /* + * this is to avoid deadlock: + * - lock_page(sum_page) - f2fs_replace_block + * - check_valid_map() - mutex_lock(sentry_lock) + * - mutex_lock(sentry_lock) - change_curseg() + * - lock_page(sum_page) + */ + unlock_page(sum_page); + switch (GET_SUM_TYPE((&sum->footer))) { case SUM_TYPE_NODE: gc_node_segment(sbi, sum->entries, segno, gc_type); @@ -763,7 +772,7 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type); stat_inc_call_count(sbi->stat_info); - f2fs_put_page(sum_page, 1); + f2fs_put_page(sum_page, 0); } int f2fs_gc(struct f2fs_sb_info *sbi) -- 2.1.1