From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFF5C220689 for ; Fri, 4 Apr 2025 19:55:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743796555; cv=none; b=OW62eVGf9/DRJjaIGMzqv37Ip5ih0I3dUXE6M9bW0XaavpewM21c0UNtqtDx2E/+vzuDpIccEa79ZNz8MZVhIIiWiPUmsZJVsS1t0IcAEasgt8tCFP8XHCqF0NEUvm5ChFKxgogtWYRC75AkP5OiosYlZlzXsw23R9cVky/4LUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743796555; c=relaxed/simple; bh=2kEGGwEpfW7hU23vb/09JvyfuhHSs2hXb2emfr4WRbA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eveZKjf8LfFNQOU5xu7kfLmhPPDs171+UKSK74slcy4++cEgv1PDkzcTM1CsPIbJfwo3esTu3HpFRdMupynvdTceTzKlP2bc4up/GkgwGeMTVVJZPR70Vf00PwiiUqMb27GhL189M+fO+PU2EXdTtwPpEnbC3xML2Pazp15l8Q0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C4NI6yjw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C4NI6yjw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06B14C4CEDD; Fri, 4 Apr 2025 19:55:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743796555; bh=2kEGGwEpfW7hU23vb/09JvyfuhHSs2hXb2emfr4WRbA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C4NI6yjwKYfqKhJM5ktdsD1ng6byy1XmmnH37NZ0AmhZARz7vJrDWz1gbPWWPnrUE YDMbv7aNTDsOlSXmtdHCOfiAYKJgcrk7pT44hjdKVY1fLV3GaYPAeT2GxHWqI9gu1N LWGRVS/hfBRSGR8UzwfoTgqaZgU4ZhC9owCXuOPqomTl+DPKFDDA+XcNRvLzI6MUE+ lPLtuXtFwwPb8qCotWIKC6tF6K7vvdgIXPaYIdDVt7Fby1fVJj9bGLs3QFzG/R9z0V 7QZIbm0kmgNC01bYGVQVKJz0FCFbV1otb33IBIWleK5HOvtzO3MGuZzzBNwpvDPsQ5 rMfdcTmBFzm+g== Date: Fri, 4 Apr 2025 19:55:53 +0000 From: Jaegeuk Kim To: "yohan.joung" Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, pilhyun.kim@sk.com Subject: Re: [PATCH v5] f2fs: prevent the current section from being selected as a victim during GC Message-ID: References: <20250403232107.2960-1-yohan.joung@sk.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250403232107.2960-1-yohan.joung@sk.com> Hi Yohan, I modified this patch after applying the clean up by https://lore.kernel.org/linux-f2fs-devel/20250404195442.413945-1-jaegeuk@kernel.org/T/#u --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -486,6 +486,11 @@ static inline void __set_test_and_free(struct f2fs_sb_info *sbi, free_i->free_sections++; + if (GET_SEC_FROM_SEG(sbi, sbi->next_victim_seg[BG_GC]) == secno) + sbi->next_victim_seg[BG_GC] = NULL_SEGNO; + if (GET_SEC_FROM_SEG(sbi, sbi->next_victim_seg[FG_GC]) == secno) + sbi->next_victim_seg[FG_GC] = NULL_SEGNO; + unlock_out: spin_unlock(&free_i->segmap_lock); } On 04/04, yohan.joung wrote: > When selecting a victim using next_victim_seg in a large section, the > selected section might already have been cleared and designated as the > new current section, making it actively in use. > This behavior causes inconsistency between the SIT and SSA. > > F2FS-fs (dm-54): Inconsistent segment (70961) type [0, 1] in SSA and SIT > Call trace: > dump_backtrace+0xe8/0x10c > show_stack+0x18/0x28 > dump_stack_lvl+0x50/0x6c > dump_stack+0x18/0x28 > f2fs_stop_checkpoint+0x1c/0x3c > do_garbage_collect+0x41c/0x271c > f2fs_gc+0x27c/0x828 > gc_thread_func+0x290/0x88c > kthread+0x11c/0x164 > ret_from_fork+0x10/0x20 > > issue scenario > segs_per_sec=2 > - seg#0 and seg#1 are all dirty > - all valid blocks are removed in seg#1 > - gc select this sec and next_victim_seg=seg#0 > - migrate seg#0, next_victim_seg=seg#1 > - checkpoint -> sec(seg#0, seg#1) becomes free > - allocator assigns sec(seg#0, seg#1) to curseg > - gc tries to migrate seg#1 > > Signed-off-by: yohan.joung > Signed-off-by: Chao Yu > --- > fs/f2fs/segment.h | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > index 0465dc00b349..0773283babfa 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -474,8 +474,15 @@ static inline void __set_test_and_free(struct f2fs_sb_info *sbi, > next = find_next_bit(free_i->free_segmap, > start_segno + SEGS_PER_SEC(sbi), start_segno); > if (next >= start_segno + usable_segs) { > - if (test_and_clear_bit(secno, free_i->free_secmap)) > + if (test_and_clear_bit(secno, free_i->free_secmap)) { > free_i->free_sections++; > + > + if (GET_SEC_FROM_SEG(sbi, sbi->next_victim_seg[BG_GC]) == secno) > + sbi->next_victim_seg[BG_GC] = NULL_SEGNO; > + > + if (GET_SEC_FROM_SEG(sbi, sbi->next_victim_seg[FG_GC]) == secno) > + sbi->next_victim_seg[FG_GC] = NULL_SEGNO; > + } > } > } > skip_free: > -- > 2.33.0