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Tue, 14 Apr 2020 09:59:01 +0000 (UTC) Received: from codeaurora.org (blr-c-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: stummala) by smtp.codeaurora.org (Postfix) with ESMTPSA id AB591C433F2; Tue, 14 Apr 2020 09:58:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AB591C433F2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=stummala@codeaurora.org Date: Tue, 14 Apr 2020 15:28:44 +0530 From: Sahitya Tummala To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, stummala@codeaurora.org Subject: Re: [f2fs-dev] [PATCH] f2fs: prevent meta updates while checkpoint is in progress Message-ID: <20200414095844.GE20234@codeaurora.org> References: <1585219019-24831-1-git-send-email-stummala@codeaurora.org> <20200331035419.GB79749@google.com> <20200331090608.GZ20234@codeaurora.org> <20200331184307.GA198665@google.com> <20200401050801.GA20234@codeaurora.org> <20200403171727.GB68460@google.com> <20200403172750.GD68460@google.com> <20200413174237.GC39092@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200413174237.GC39092@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 13, 2020 at 10:42:37AM -0700, Jaegeuk Kim wrote: > On 04/03, Jaegeuk Kim wrote: > > On 04/03, Jaegeuk Kim wrote: > > > On 04/01, Sahitya Tummala wrote: > > > > Hi Jaegeuk, > > > > > > > > Got it. > > > > The diff below looks good to me. > > > > Would you like me to test it and put a patch for this? > > > > > > Sahitya, Chao, > > > > > > Could you please take a look at this patch and test intensively? > > > > > > Thanks, > v3: > - fix gc_lock > > From d10c09dfedc7a10cef7dd34493ddbd7c27889033 Mon Sep 17 00:00:00 2001 > From: Jaegeuk Kim > Date: Tue, 31 Mar 2020 11:43:07 -0700 > Subject: [PATCH] f2fs: refactor resize_fs to avoid meta updates in progress > > Sahitya raised an issue: > - prevent meta updates while checkpoint is in progress > > allocate_segment_for_resize() can cause metapage updates if > it requires to change the current node/data segments for resizing. > Stop these meta updates when there is a checkpoint already > in progress to prevent inconsistent CP data. > > Signed-off-by: Sahitya Tummala > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/checkpoint.c | 6 ++- > fs/f2fs/f2fs.h | 2 +- > fs/f2fs/file.c | 5 +- > fs/f2fs/gc.c | 105 ++++++++++++++++++++---------------- > fs/f2fs/super.c | 1 - > include/trace/events/f2fs.h | 4 +- > 6 files changed, 67 insertions(+), 56 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 6be357c8e0020..dcb3a15574c99 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -1554,7 +1554,8 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > return 0; > f2fs_warn(sbi, "Start checkpoint disabled!"); > } > - mutex_lock(&sbi->cp_mutex); > + if (cpc->reason != CP_RESIZE) > + mutex_lock(&sbi->cp_mutex); > > if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) && > ((cpc->reason & CP_FASTBOOT) || (cpc->reason & CP_SYNC) || > @@ -1623,7 +1624,8 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > f2fs_update_time(sbi, CP_TIME); > trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint"); > out: > - mutex_unlock(&sbi->cp_mutex); > + if (cpc->reason != CP_RESIZE) > + mutex_unlock(&sbi->cp_mutex); > return err; > } > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 1241a397bf53c..e8e26ab723eba 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -194,6 +194,7 @@ enum { > #define CP_DISCARD 0x00000010 > #define CP_TRIMMED 0x00000020 > #define CP_PAUSE 0x00000040 > +#define CP_RESIZE 0x00000080 > > #define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi) > #define DEF_MAX_DISCARD_REQUEST 8 /* issue 8 discards per round */ > @@ -1422,7 +1423,6 @@ struct f2fs_sb_info { > unsigned int segs_per_sec; /* segments per section */ > unsigned int secs_per_zone; /* sections per zone */ > unsigned int total_sections; /* total section count */ > - struct mutex resize_mutex; /* for resize exclusion */ > unsigned int total_node_count; /* total node block count */ > unsigned int total_valid_node_count; /* valid node block count */ > loff_t max_file_blocks; /* max block index of file */ > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index f06b029c00d8d..0514fab8d2eb8 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -3313,7 +3313,6 @@ static int f2fs_ioc_resize_fs(struct file *filp, unsigned long arg) > { > struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp)); > __u64 block_count; > - int ret; > > if (!capable(CAP_SYS_ADMIN)) > return -EPERM; > @@ -3325,9 +3324,7 @@ static int f2fs_ioc_resize_fs(struct file *filp, unsigned long arg) > sizeof(block_count))) > return -EFAULT; > > - ret = f2fs_resize_fs(sbi, block_count); > - > - return ret; > + return f2fs_resize_fs(sbi, block_count); > } > > static int f2fs_ioc_enable_verity(struct file *filp, unsigned long arg) > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index 26248c8936db0..3d003397252b8 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -1399,12 +1399,29 @@ void f2fs_build_gc_manager(struct f2fs_sb_info *sbi) > GET_SEGNO(sbi, FDEV(0).end_blk) + 1; > } > > -static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start, > - unsigned int end) > +static int free_segment_range(struct f2fs_sb_info *sbi, > + unsigned int secs, bool gc_only) > { > - int type; > - unsigned int segno, next_inuse; > + unsigned int segno, next_inuse, start, end; > + struct cp_control cpc = { CP_RESIZE, 0, 0, 0 }; > + int gc_mode, gc_type; > int err = 0; > + int type; > + > + /* Force block allocation for GC */ > + MAIN_SECS(sbi) -= secs; > + start = MAIN_SECS(sbi) * sbi->segs_per_sec; > + end = MAIN_SEGS(sbi) - 1; > + > + mutex_lock(&DIRTY_I(sbi)->seglist_lock); > + for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++) > + if (SIT_I(sbi)->last_victim[gc_mode] >= start) > + SIT_I(sbi)->last_victim[gc_mode] = 0; > + > + for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++) > + if (sbi->next_victim_seg[gc_type] >= start) > + sbi->next_victim_seg[gc_type] = NULL_SEGNO; > + mutex_unlock(&DIRTY_I(sbi)->seglist_lock); > > /* Move out cursegs from the target range */ > for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) > @@ -1422,13 +1439,17 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start, > up_write(&sbi->gc_lock); > put_gc_inode(&gc_list); > > - if (get_valid_blocks(sbi, segno, true)) > - return -EAGAIN; > + if (!gc_only && get_valid_blocks(sbi, segno, true)) { > + err = -EAGAIN; > + goto out; > + } > } > + if (gc_only) > + goto out; > > - err = f2fs_sync_fs(sbi->sb, 1); > + err = f2fs_write_checkpoint(sbi, &cpc); > if (err) > - return err; > + goto out; > > next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start); > if (next_inuse <= end) { > @@ -1436,6 +1457,8 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start, > next_inuse); > f2fs_bug_on(sbi, 1); > } > +out: > + MAIN_SECS(sbi) -= secs; > return err; > } > > @@ -1481,6 +1504,7 @@ static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs) > > SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs; > MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs; > + MAIN_SECS(sbi) += secs; > FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs; > FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs; > F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks); > @@ -1502,8 +1526,8 @@ static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs) > int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) > { > __u64 old_block_count, shrunk_blocks; > + struct cp_control cpc = { CP_RESIZE, 0, 0, 0 }; > unsigned int secs; > - int gc_mode, gc_type; > int err = 0; > __u32 rem; > > @@ -1538,10 +1562,22 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) > return -EINVAL; > } > > - freeze_bdev(sbi->sb->s_bdev); > - > shrunk_blocks = old_block_count - block_count; > secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi)); > + > + /* protect MAIN_SEC in free_segment_range */ > + f2fs_lock_op(sbi); > + err = free_segment_range(sbi, secs, true); > + f2fs_unlock_op(sbi); > + if (err) > + return err; > + > + set_sbi_flag(sbi, SBI_IS_RESIZEFS); > + > + freeze_super(sbi->sb); > + down_write(&sbi->gc_lock); free_segment_range() tries to acquire the gc_lock before do_garbage_collect(). It can deadlock. Thanks, > + mutex_lock(&sbi->cp_mutex); > + > spin_lock(&sbi->stat_lock); > if (shrunk_blocks + valid_user_blocks(sbi) + > sbi->current_reserved_blocks + sbi->unusable_block_count + > @@ -1550,69 +1586,44 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) > else > sbi->user_block_count -= shrunk_blocks; > spin_unlock(&sbi->stat_lock); > - if (err) { > - thaw_bdev(sbi->sb->s_bdev, sbi->sb); > - return err; > - } > - > - mutex_lock(&sbi->resize_mutex); > - set_sbi_flag(sbi, SBI_IS_RESIZEFS); > - > - mutex_lock(&DIRTY_I(sbi)->seglist_lock); > - > - MAIN_SECS(sbi) -= secs; > - > - for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++) > - if (SIT_I(sbi)->last_victim[gc_mode] >= > - MAIN_SECS(sbi) * sbi->segs_per_sec) > - SIT_I(sbi)->last_victim[gc_mode] = 0; > - > - for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++) > - if (sbi->next_victim_seg[gc_type] >= > - MAIN_SECS(sbi) * sbi->segs_per_sec) > - sbi->next_victim_seg[gc_type] = NULL_SEGNO; > - > - mutex_unlock(&DIRTY_I(sbi)->seglist_lock); > + if (err) > + goto out_err; > > - err = free_segment_range(sbi, MAIN_SECS(sbi) * sbi->segs_per_sec, > - MAIN_SEGS(sbi) - 1); > + err = free_segment_range(sbi, secs, false); > if (err) > - goto out; > + goto recover_out; > > update_sb_metadata(sbi, -secs); > > err = f2fs_commit_super(sbi, false); > if (err) { > update_sb_metadata(sbi, secs); > - goto out; > + goto recover_out; > } > > - mutex_lock(&sbi->cp_mutex); > update_fs_metadata(sbi, -secs); > clear_sbi_flag(sbi, SBI_IS_RESIZEFS); > set_sbi_flag(sbi, SBI_IS_DIRTY); > - mutex_unlock(&sbi->cp_mutex); > > - err = f2fs_sync_fs(sbi->sb, 1); > + err = f2fs_write_checkpoint(sbi, &cpc); > if (err) { > - mutex_lock(&sbi->cp_mutex); > update_fs_metadata(sbi, secs); > - mutex_unlock(&sbi->cp_mutex); > update_sb_metadata(sbi, secs); > f2fs_commit_super(sbi, false); > } > -out: > +recover_out: > if (err) { > set_sbi_flag(sbi, SBI_NEED_FSCK); > f2fs_err(sbi, "resize_fs failed, should run fsck to repair!"); > > - MAIN_SECS(sbi) += secs; > spin_lock(&sbi->stat_lock); > sbi->user_block_count += shrunk_blocks; > spin_unlock(&sbi->stat_lock); > } > +out_err: > + mutex_unlock(&sbi->cp_mutex); > + up_write(&sbi->gc_lock); > + thaw_super(sbi->sb); > clear_sbi_flag(sbi, SBI_IS_RESIZEFS); > - mutex_unlock(&sbi->resize_mutex); > - thaw_bdev(sbi->sb->s_bdev, sbi->sb); > return err; > } > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index f2dfc21c6abb0..18b4a43a13438 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -3413,7 +3413,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) > init_rwsem(&sbi->gc_lock); > mutex_init(&sbi->writepages); > mutex_init(&sbi->cp_mutex); > - mutex_init(&sbi->resize_mutex); > init_rwsem(&sbi->node_write); > init_rwsem(&sbi->node_change); > > diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h > index e78c8696e2adc..e1ad392aae05a 100644 > --- a/include/trace/events/f2fs.h > +++ b/include/trace/events/f2fs.h > @@ -50,6 +50,7 @@ TRACE_DEFINE_ENUM(CP_RECOVERY); > TRACE_DEFINE_ENUM(CP_DISCARD); > TRACE_DEFINE_ENUM(CP_TRIMMED); > TRACE_DEFINE_ENUM(CP_PAUSE); > +TRACE_DEFINE_ENUM(CP_RESIZE); > > #define show_block_type(type) \ > __print_symbolic(type, \ > @@ -126,7 +127,8 @@ TRACE_DEFINE_ENUM(CP_PAUSE); > { CP_RECOVERY, "Recovery" }, \ > { CP_DISCARD, "Discard" }, \ > { CP_PAUSE, "Pause" }, \ > - { CP_TRIMMED, "Trimmed" }) > + { CP_TRIMMED, "Trimmed" }, \ > + { CP_RESIZE, "Resize" }) > > #define show_fsync_cpreason(type) \ > __print_symbolic(type, \ > -- > 2.26.0.110.g2183baf09c-goog > -- -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.