| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 12 Jan 2021 09:45:20 +0900
From: Daeho Jeong <daeho43@...il.com>
To: Jaegeuk Kim <jaegeuk@...nel.org>
Cc: linux-kernel@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net, kernel-team@...roid.com,
Sungjong Seo <sj1557.seo@...sung.com>,
Daeho Jeong <daehojeong@...gle.com>
Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: introduce checkpoint=merge mount option
Got it~ :)
2021년 1월 11일 (월) 오후 6:50, Jaegeuk Kim <jaegeuk@...nel.org>님이 작성:
>
> On 01/11, Daeho Jeong wrote:
> > From: Daeho Jeong <daehojeong@...gle.com>
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares, and The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> > "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> > done"
> > - thread B => gererating async. I/O
> > "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> > --filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> > "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> > fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/ patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong <daehojeong@...gle.com>
> > Signed-off-by: Sungjong Seo <sj1557.seo@...sung.com>
> > ---
> > Documentation/filesystems/f2fs.rst | 6 +
> > fs/f2fs/checkpoint.c | 176 +++++++++++++++++++++++++++++
> > fs/f2fs/debug.c | 6 +
> > fs/f2fs/f2fs.h | 24 ++++
> > fs/f2fs/super.c | 53 ++++++++-
> > 5 files changed, 261 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..bccc021bf31a 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "enabl
> > hide up to all remaining free space. The actual space that
> > would be unusable can be viewed at /sys/fs/f2fs/<disk>/unusable
> > This space is reclaimed once checkpoint=enable.
> > + Here is another option "merge", which creates a kernel daemon
> > + and makes it to merge concurrent checkpoint requests as much
> > + as possible to eliminate redundant checkpoint issues. Plus,
> > + we can eliminate the sluggish issue caused by slow checkpoint
> > + operation when the checkpoint is done in a process context in
> > + a cgroup having low i/o budget and cpu shares.
> > compress_algorithm=%s Control compress algorithm, currently f2fs supports "lzo",
> > "lz4", "zstd" and "lzo-rle" algorithm.
> > compress_log_size=%u Support configuring compress cluster size, the size will
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 897edb7c951a..11288f435dbe 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -13,6 +13,7 @@
> > #include <linux/f2fs_fs.h>
> > #include <linux/pagevec.h>
> > #include <linux/swap.h>
> > +#include <linux/kthread.h>
> >
> > #include "f2fs.h"
> > #include "node.h"
> > @@ -20,6 +21,8 @@
> > #include "trace.h"
> > #include <trace/events/f2fs.h>
> >
> > +#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
> > +
> > static struct kmem_cache *ino_entry_slab;
> > struct kmem_cache *f2fs_inode_entry_slab;
> >
> > @@ -1707,3 +1710,176 @@ void f2fs_destroy_checkpoint_caches(void)
> > kmem_cache_destroy(ino_entry_slab);
> > kmem_cache_destroy(f2fs_inode_entry_slab);
> > }
> > +
> > +static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
> > +{
> > + struct cp_control cpc = { .reason = CP_SYNC, };
> > + int err;
> > +
> > + down_write(&sbi->gc_lock);
> > + err = f2fs_write_checkpoint(sbi, &cpc);
> > + up_write(&sbi->gc_lock);
> > +
> > + return err;
> > +}
> > +
> > +static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
> > +{
> > + struct ckpt_req_control *cprc = sbi->cprc_info;
> > + struct ckpt_req *req, *next;
> > + struct llist_node *dispatch_list;
> > + int ret;
> > +
> > + dispatch_list = llist_del_all(&cprc->issue_list);
> > + if (!dispatch_list)
> > + return;
> > + dispatch_list = llist_reverse_order(dispatch_list);
> > +
> > + ret = __write_checkpoint_sync(sbi);
> > + atomic_inc(&cprc->issued_ckpt);
> > +
> > + llist_for_each_entry_safe(req, next, dispatch_list, llnode) {
> > + atomic_dec(&cprc->queued_ckpt);
> > + atomic_inc(&cprc->total_ckpt);
> > + req->complete_time = jiffies;
> > + req->ret = ret;
> > + complete(&req->wait);
> > + }
> > +}
> > +
> > +static int issue_checkpoint_thread(void *data)
> > +{
> > + struct f2fs_sb_info *sbi = data;
> > + struct ckpt_req_control *cprc = sbi->cprc_info;
> > + wait_queue_head_t *q = &cprc->ckpt_wait_queue;
> > +repeat:
> > + if (kthread_should_stop())
> > + return 0;
> > +
> > + sb_start_intwrite(sbi->sb);
> > +
> > + if (!llist_empty(&cprc->issue_list))
> > + __checkpoint_and_complete_reqs(sbi);
> > +
> > + sb_end_intwrite(sbi->sb);
> > +
> > + wait_event_interruptible(*q,
> > + kthread_should_stop() || !llist_empty(&cprc->issue_list));
> > + goto repeat;
> > +}
> > +
> > +static void flush_remained_ckpt_reqs(struct f2fs_sb_info *sbi,
> > + struct ckpt_req *wait_req)
> > +{
> > + struct ckpt_req_control *cprc = sbi->cprc_info;
> > +
> > + if (!llist_empty(&cprc->issue_list)) {
> > + __checkpoint_and_complete_reqs(sbi);
> > + } else {
> > + /* already dispatched by issue_checkpoint_thread */
> > + if (wait_req)
> > + wait_for_completion(&wait_req->wait);
> > + }
> > +}
> > +
> > +static void init_ckpt_req(struct ckpt_req *req)
> > +{
> > + memset(req, 0, sizeof(struct ckpt_req));
> > +
> > + req->owner = current;
> > + init_completion(&req->wait);
> > +}
> > +
> > +int f2fs_issue_checkpoint(struct f2fs_sb_info *sbi)
> > +{
> > + struct ckpt_req_control *cprc = sbi->cprc_info;
> > + struct ckpt_req req;
> > +
> > + if (!cprc || !cprc->f2fs_issue_ckpt)
> > + return __write_checkpoint_sync(sbi);
> > +
> > + init_ckpt_req(&req);
> > +
> > + req.queue_time = jiffies;
> > + llist_add(&req.llnode, &cprc->issue_list);
> > + atomic_inc(&cprc->queued_ckpt);
> > +
> > + /* update issue_list before we wake up issue_checkpoint thread */
> > + smp_mb();
> > +
> > + if (waitqueue_active(&cprc->ckpt_wait_queue))
> > + wake_up(&cprc->ckpt_wait_queue);
> > +
> > + if (cprc->f2fs_issue_ckpt)
> > + wait_for_completion(&req.wait);
> > + else
> > + flush_remained_ckpt_reqs(sbi, &req);
> > +
> > + return req.ret;
> > +}
> > +
> > +int f2fs_create_ckpt_req_control(struct f2fs_sb_info *sbi)
> > +{
> > + dev_t dev = sbi->sb->s_bdev->bd_dev;
> > + struct ckpt_req_control *cprc;
> > + bool need_free = true;
> > +
> > + if (sbi->cprc_info) {
> > + cprc = sbi->cprc_info;
> > + if (cprc->f2fs_issue_ckpt)
> > + return 0;
> > +
> > + need_free = false;
> > + goto init_thread;
> > + }
> > +
> > + cprc = f2fs_kzalloc(sbi, sizeof(struct ckpt_req_control), GFP_KERNEL);
> > + if (!cprc)
> > + return -ENOMEM;
> > + atomic_set(&cprc->issued_ckpt, 0);
> > + atomic_set(&cprc->total_ckpt, 0);
> > + atomic_set(&cprc->queued_ckpt, 0);
> > + init_waitqueue_head(&cprc->ckpt_wait_queue);
> > + init_llist_head(&cprc->issue_list);
> > + sbi->cprc_info = cprc;
> > +
> > +init_thread:
> > + if (!test_opt(sbi, MERGE_CHECKPOINT))
> > + return 0;
> > +
> > + cprc->f2fs_issue_ckpt = kthread_run(issue_checkpoint_thread, sbi,
> > + "f2fs_ckpt-%u:%u", MAJOR(dev), MINOR(dev));
> > + if (IS_ERR(cprc->f2fs_issue_ckpt)) {
> > + int err = PTR_ERR(cprc->f2fs_issue_ckpt);
> > +
> > + if (need_free) {
> > + kvfree(cprc);
> > + sbi->cprc_info = NULL;
> > + }
> > + return err;
> > + }
> > +
> > + set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
> > +
> > + return 0;
> > +}
> > +
> > +void f2fs_destroy_ckpt_req_control(struct f2fs_sb_info *sbi, bool free)
> > +{
> > + struct ckpt_req_control *cprc = sbi->cprc_info;
> > +
> > + if (cprc && cprc->f2fs_issue_ckpt) {
> > + struct task_struct *ckpt_task = cprc->f2fs_issue_ckpt;
> > +
> > + cprc->f2fs_issue_ckpt = NULL;
> > + kthread_stop(ckpt_task);
> > +
> > + flush_remained_ckpt_reqs(sbi, NULL);
> > + }
> > +
> > + if (free) {
> > + kvfree(cprc);
> > + sbi->cprc_info = NULL;
> > + }
> > +}
> > +
>
> Git complained an empty space.
>
> > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> > index 197c914119da..6ee81afae6b7 100644
> > --- a/fs/f2fs/debug.c
> > +++ b/fs/f2fs/debug.c
> > @@ -120,6 +120,9 @@ static void update_general_status(struct f2fs_sb_info *sbi)
> > atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
> > si->undiscard_blks = SM_I(sbi)->dcc_info->undiscard_blks;
> > }
> > + si->nr_issued_ckpt = atomic_read(&sbi->cprc_info->issued_ckpt);
> > + si->nr_total_ckpt = atomic_read(&sbi->cprc_info->total_ckpt);
> > + si->nr_queued_ckpt = atomic_read(&sbi->cprc_info->queued_ckpt);
>
> Here, we can get null cprc_info.
>
> > si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
> > si->rsvd_segs = reserved_segments(sbi);
> > si->overp_segs = overprovision_segments(sbi);
> > @@ -417,6 +420,9 @@ static int stat_show(struct seq_file *s, void *v)
> > si->meta_count[META_NAT]);
> > seq_printf(s, " - ssa blocks : %u\n",
> > si->meta_count[META_SSA]);
> > + seq_printf(s, "CP merge (Queued: %4d, Issued: %4d, Total: %4d)\n",
> > + si->nr_queued_ckpt, si->nr_issued_ckpt,
> > + si->nr_total_ckpt);
> > seq_printf(s, "GC calls: %d (BG: %d)\n",
> > si->call_count, si->bg_gc);
> > seq_printf(s, " - data segments : %d (%d)\n",
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index bb11759191dc..4de5285df17d 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -97,6 +97,7 @@ extern const char *f2fs_fault_name[FAULT_MAX];
> > #define F2FS_MOUNT_DISABLE_CHECKPOINT 0x02000000
> > #define F2FS_MOUNT_NORECOVERY 0x04000000
> > #define F2FS_MOUNT_ATGC 0x08000000
> > +#define F2FS_MOUNT_MERGE_CHECKPOINT 0x10000000
> >
> > #define F2FS_OPTION(sbi) ((sbi)->mount_opt)
> > #define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
> > @@ -266,6 +267,24 @@ struct fsync_node_entry {
> > unsigned int seq_id; /* sequence id */
> > };
> >
> > +struct ckpt_req {
> > + struct completion wait;
> > + struct llist_node llnode;
> > + int ret;
> > + struct task_struct *owner;
> > + unsigned long queue_time; /* request queued time in jiffies */
> > + unsigned long complete_time; /* request completed time in jiffies */
> > +};
> > +
> > +struct ckpt_req_control {
> > + struct task_struct *f2fs_issue_ckpt; /* checkpoint task */
> > + wait_queue_head_t ckpt_wait_queue; /* waiting queue for wake-up */
> > + atomic_t issued_ckpt; /* # of actually issued ckpts */
> > + atomic_t total_ckpt; /* # of total ckpts */
> > + atomic_t queued_ckpt; /* # of queued ckpts */
> > + struct llist_head issue_list; /* list for command issue */
> > +};
> > +
> > /* for the bitmap indicate blocks to be discarded */
> > struct discard_entry {
> > struct list_head list; /* list head */
> > @@ -1404,6 +1423,7 @@ struct f2fs_sb_info {
> > wait_queue_head_t cp_wait;
> > unsigned long last_time[MAX_TIME]; /* to store time in jiffies */
> > long interval_time[MAX_TIME]; /* to store thresholds */
> > + struct ckpt_req_control *cprc_info; /* for checkpoint request control */
> >
> > struct inode_management im[MAX_INO_ENTRY]; /* manage inode cache */
> >
> > @@ -3418,6 +3438,9 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc);
> > void f2fs_init_ino_entry_info(struct f2fs_sb_info *sbi);
> > int __init f2fs_create_checkpoint_caches(void);
> > void f2fs_destroy_checkpoint_caches(void);
> > +int f2fs_issue_checkpoint(struct f2fs_sb_info *sbi);
> > +int f2fs_create_ckpt_req_control(struct f2fs_sb_info *sbi);
> > +void f2fs_destroy_ckpt_req_control(struct f2fs_sb_info *sbi, bool free);
> >
> > /*
> > * data.c
> > @@ -3530,6 +3553,7 @@ struct f2fs_stat_info {
> > int nr_discarding, nr_discarded;
> > int nr_discard_cmd;
> > unsigned int undiscard_blks;
> > + int nr_issued_ckpt, nr_total_ckpt, nr_queued_ckpt;
> > int inline_xattr, inline_inode, inline_dir, append, update, orphans;
> > int compr_inode;
> > unsigned long long compr_blocks;
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index b4a07fe62d1a..5cd89c231223 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -143,6 +143,7 @@ enum {
> > Opt_checkpoint_disable_cap,
> > Opt_checkpoint_disable_cap_perc,
> > Opt_checkpoint_enable,
> > + Opt_checkpoint_merge,
> > Opt_compress_algorithm,
> > Opt_compress_log_size,
> > Opt_compress_extension,
> > @@ -213,6 +214,7 @@ static match_table_t f2fs_tokens = {
> > {Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
> > {Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
> > {Opt_checkpoint_enable, "checkpoint=enable"},
> > + {Opt_checkpoint_merge, "checkpoint=merge"},
> > {Opt_compress_algorithm, "compress_algorithm=%s"},
> > {Opt_compress_log_size, "compress_log_size=%u"},
> > {Opt_compress_extension, "compress_extension=%s"},
> > @@ -872,6 +874,9 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> > case Opt_checkpoint_enable:
> > clear_opt(sbi, DISABLE_CHECKPOINT);
> > break;
> > + case Opt_checkpoint_merge:
> > + set_opt(sbi, MERGE_CHECKPOINT);
> > + break;
> > #ifdef CONFIG_F2FS_FS_COMPRESSION
> > case Opt_compress_algorithm:
> > if (!f2fs_sb_has_compression(sbi)) {
> > @@ -1040,6 +1045,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> > return -EINVAL;
> > }
> >
> > + if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > + test_opt(sbi, MERGE_CHECKPOINT)) {
> > + f2fs_err(sbi, "checkpoint=merge cannot be used with checkpoint=disable\n");
> > + return -EINVAL;
> > + }
> > +
> > /* Not pass down write hints if the number of active logs is lesser
> > * than NR_CURSEG_PERSIST_TYPE.
> > */
> > @@ -1245,6 +1256,12 @@ static void f2fs_put_super(struct super_block *sb)
> > /* prevent remaining shrinker jobs */
> > mutex_lock(&sbi->umount_mutex);
> >
> > + /*
> > + * flush all issued checkpoints and destroy checkpoint request control.
> > + * after then, all checkpoints should be done by each process context.
> > + */
> > + f2fs_destroy_ckpt_req_control(sbi, true);
> > +
> > /*
> > * We don't need to do checkpoint when superblock is clean.
> > * But, the previous checkpoint was not done by umount, it needs to do
> > @@ -1347,10 +1364,13 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
> > struct cp_control cpc;
> >
> > cpc.reason = __get_cp_reason(sbi);
> > -
> > - down_write(&sbi->gc_lock);
> > - err = f2fs_write_checkpoint(sbi, &cpc);
> > - up_write(&sbi->gc_lock);
> > + if (test_opt(sbi, MERGE_CHECKPOINT) && cpc.reason == CP_SYNC) {
> > + err = f2fs_issue_checkpoint(sbi);
> > + } else {
> > + down_write(&sbi->gc_lock);
> > + err = f2fs_write_checkpoint(sbi, &cpc);
> > + up_write(&sbi->gc_lock);
> > + }
> > }
> > f2fs_trace_ios(NULL, 1);
> >
> > @@ -1674,6 +1694,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> > if (test_opt(sbi, DISABLE_CHECKPOINT))
> > seq_printf(seq, ",checkpoint=disable:%u",
> > F2FS_OPTION(sbi).unusable_cap);
> > + if (test_opt(sbi, MERGE_CHECKPOINT))
> > + seq_puts(seq, ",checkpoint=merge");
> > if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
> > seq_printf(seq, ",fsync_mode=%s", "posix");
> > else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
> > @@ -1954,6 +1976,18 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> > }
> > }
> >
> > + if (!test_opt(sbi, MERGE_CHECKPOINT)) {
> > + f2fs_destroy_ckpt_req_control(sbi, false);
> > + } else {
> > + err = f2fs_create_ckpt_req_control(sbi);
> > + if (err) {
> > + f2fs_err(sbi,
> > + "Failed to initialize F2FS issue_checkpoint_thread (%d)",
> > + err);
> > + goto restore_gc;
> > + }
> > + }
> > +
> > /*
> > * We stop issue flush thread if FS is mounted as RO
> > * or if flush_merge is not passed in mount option.
> > @@ -3701,6 +3735,15 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >
> > f2fs_init_fsync_node_info(sbi);
> >
> > + /* setup checkpoint request control */
> > + err = f2fs_create_ckpt_req_control(sbi);
> > + if (err) {
> > + f2fs_err(sbi,
> > + "Failed to initialize F2FS checkpoint request control (%d)",
> > + err);
> > + goto free_cprc;
> > + }
> > +
> > /* setup f2fs internal modules */
> > err = f2fs_build_segment_manager(sbi);
> > if (err) {
> > @@ -3910,6 +3953,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > free_sm:
> > f2fs_destroy_segment_manager(sbi);
> > f2fs_destroy_post_read_wq(sbi);
> > +free_cprc:
> > + f2fs_destroy_ckpt_req_control(sbi, true);
> > free_devices:
> > destroy_device_list(sbi);
> > kvfree(sbi->ckpt);
> > --
> > 2.30.0.284.gd98b1dd5eaa7-goog
> >
> >
> >
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@...ts.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Powered by blists - more mailing lists