Messages in this thread | | | Date | Thu, 13 Jun 2019 19:46:55 -0700 | From | Jaegeuk Kim <> | Subject | Re: [f2fs-dev] [PATCH v3] f2fs: add a rw_sem to cover quota flag changes |
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On 06/11, Chao Yu wrote: > On 2019/6/5 2:36, Jaegeuk Kim wrote: > > Two paths to update quota and f2fs_lock_op: > > > > 1. > > - lock_op > > | - quota_update > > `- unlock_op > > > > 2. > > - quota_update > > - lock_op > > `- unlock_op > > > > But, we need to make a transaction on quota_update + lock_op in #2 case. > > So, this patch introduces: > > 1. lock_op > > 2. down_write > > 3. check __need_flush > > 4. up_write > > 5. if there is dirty quota entries, flush them > > 6. otherwise, good to go > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > > --- > > > > v3 from v2: > > - refactor to fix quota corruption issue > > : it seems that the previous scenario is not real and no deadlock case was > > encountered. > > - f2fs_dquot_commit > - down_read(&sbi->quota_sem) > - block_operation > - f2fs_lock_all > - need_flush_quota > - down_write(&sbi->quota_sem) > - f2fs_quota_write > - f2fs_lock_op > > Why can't this happen? > > Once more question, should we hold quota_sem during checkpoint to avoid further > quota update? f2fs_lock_op can do this job as well?
I couldn't find write_dquot() call to make this happen, and f2fs_lock_op was not enough to cover quota updates. Current stress & power-cut tests are running for several days without problem with this patch.
> > Thanks, > > > > > fs/f2fs/checkpoint.c | 41 +++++++++++++++++++---------------------- > > fs/f2fs/f2fs.h | 1 + > > fs/f2fs/super.c | 26 +++++++++++++++++++++----- > > 3 files changed, 41 insertions(+), 27 deletions(-) > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > index 89825261d474..43f65f0962e5 100644 > > --- a/fs/f2fs/checkpoint.c > > +++ b/fs/f2fs/checkpoint.c > > @@ -1131,17 +1131,24 @@ static void __prepare_cp_block(struct f2fs_sb_info *sbi) > > > > static bool __need_flush_quota(struct f2fs_sb_info *sbi) > > { > > + bool ret = false; > > + > > if (!is_journalled_quota(sbi)) > > return false; > > - if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH)) > > - return false; > > - if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)) > > - return false; > > - if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_FLUSH)) > > - return true; > > - if (get_pages(sbi, F2FS_DIRTY_QDATA)) > > - return true; > > - return false; > > + > > + down_write(&sbi->quota_sem); > > + if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH)) { > > + ret = false; > > + } else if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)) { > > + ret = false; > > + } else if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_FLUSH)) { > > + clear_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); > > + ret = true; > > + } else if (get_pages(sbi, F2FS_DIRTY_QDATA)) { > > + ret = true; > > + } > > + up_write(&sbi->quota_sem); > > + return ret; > > } > > > > /* > > @@ -1160,26 +1167,22 @@ static int block_operations(struct f2fs_sb_info *sbi) > > blk_start_plug(&plug); > > > > retry_flush_quotas: > > + f2fs_lock_all(sbi); > > if (__need_flush_quota(sbi)) { > > int locked; > > > > if (++cnt > DEFAULT_RETRY_QUOTA_FLUSH_COUNT) { > > set_sbi_flag(sbi, SBI_QUOTA_SKIP_FLUSH); > > - f2fs_lock_all(sbi); > > + set_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); > > goto retry_flush_dents; > > } > > - clear_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); > > + f2fs_unlock_all(sbi); > > > > /* only failed during mount/umount/freeze/quotactl */ > > locked = down_read_trylock(&sbi->sb->s_umount); > > f2fs_quota_sync(sbi->sb, -1); > > if (locked) > > up_read(&sbi->sb->s_umount); > > - } > > - > > - f2fs_lock_all(sbi); > > - if (__need_flush_quota(sbi)) { > > - f2fs_unlock_all(sbi); > > cond_resched(); > > goto retry_flush_quotas; > > } > > @@ -1201,12 +1204,6 @@ static int block_operations(struct f2fs_sb_info *sbi) > > */ > > down_write(&sbi->node_change); > > > > - if (__need_flush_quota(sbi)) { > > - up_write(&sbi->node_change); > > - f2fs_unlock_all(sbi); > > - goto retry_flush_quotas; > > - } > > - > > if (get_pages(sbi, F2FS_DIRTY_IMETA)) { > > up_write(&sbi->node_change); > > f2fs_unlock_all(sbi); > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index 9674a85154b2..9bd2bf0f559b 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -1253,6 +1253,7 @@ struct f2fs_sb_info { > > block_t unusable_block_count; /* # of blocks saved by last cp */ > > > > unsigned int nquota_files; /* # of quota sysfile */ > > + struct rw_semaphore quota_sem; /* blocking cp for flags */ > > > > /* # of pages, see count_type */ > > atomic_t nr_pages[NR_COUNT_TYPE]; > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > index 15d7e30bfc72..5a318399a2fa 100644 > > --- a/fs/f2fs/super.c > > +++ b/fs/f2fs/super.c > > @@ -1964,6 +1964,7 @@ int f2fs_quota_sync(struct super_block *sb, int type) > > int cnt; > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_writeback_dquots(sb, type); > > if (ret) > > goto out; > > @@ -2001,6 +2002,7 @@ int f2fs_quota_sync(struct super_block *sb, int type) > > out: > > if (ret) > > set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR); > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > @@ -2094,32 +2096,40 @@ static void f2fs_truncate_quota_inode_pages(struct super_block *sb) > > > > static int f2fs_dquot_commit(struct dquot *dquot) > > { > > + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_commit(dquot); > > if (ret < 0) > > - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); > > + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > static int f2fs_dquot_acquire(struct dquot *dquot) > > { > > + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_acquire(dquot); > > if (ret < 0) > > - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); > > - > > + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > static int f2fs_dquot_release(struct dquot *dquot) > > { > > + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_release(dquot); > > if (ret < 0) > > - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); > > + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > @@ -2129,22 +2139,27 @@ static int f2fs_dquot_mark_dquot_dirty(struct dquot *dquot) > > struct f2fs_sb_info *sbi = F2FS_SB(sb); > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_mark_dquot_dirty(dquot); > > > > /* if we are using journalled quota */ > > if (is_journalled_quota(sbi)) > > set_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); > > > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > static int f2fs_dquot_commit_info(struct super_block *sb, int type) > > { > > + struct f2fs_sb_info *sbi = F2FS_SB(sb); > > int ret; > > > > + down_read(&sbi->quota_sem); > > ret = dquot_commit_info(sb, type); > > if (ret < 0) > > - set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR); > > + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); > > + up_read(&sbi->quota_sem); > > return ret; > > } > > > > @@ -3253,6 +3268,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) > > } > > > > init_rwsem(&sbi->cp_rwsem); > > + init_rwsem(&sbi->quota_sem); > > init_waitqueue_head(&sbi->cp_wait); > > init_sb_info(sbi); > > > >
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