Re: [f2fs-dev] [PATCH v4] f2fs: introduce discard_granularity sysfs entry
From: Ju Hyung Park
Date: Tue Oct 03 2017 - 14:15:00 EST
Hi Chao.
Yep, that patch seems to have fixed it.
Doing "while true; do fstrim -v /; done" while "rm -rf"ing a 2GB
kbuild directory
(with lots of small .o files and stuff) ended flawlessly.
I hope to see this patch merged with next 4.14 merge cycle.
Thanks :)
On Tue, Oct 3, 2017 at 12:59 AM, Chao Yu <chao@xxxxxxxxxx> wrote:
> Hi Park,
>
> Thanks for the report, could have a try with below patch:
>
> From 5fa30e8cdcb93f210e25142c48a884be383c6121 Mon Sep 17 00:00:00 2001
> From: Chao Yu <yuchao0@xxxxxxxxxx>
> Date: Mon, 2 Oct 2017 02:50:16 +0800
> Subject: [PATCH] f2fs: fix potential panic during fstrim
>
> As Ju Hyung Park reported:
>
> "When 'fstrim' is called for manual trim, a BUG() can be triggered
> randomly with this patch.
>
> I'm seeing this issue on both x86 Desktop and arm64 Android phone.
>
> On x86 Desktop, this was caused during Ubuntu boot-up. I have a
> cronjob installed which calls 'fstrim -v /' during boot. On arm64
> Android, this was caused during GC looping with 1ms gc_min_sleep_time
> & gc_max_sleep_time."
>
> Root cause of this issue is that f2fs_wait_discard_bios can only be
> used by f2fs_put_super, because during put_super there must be no
> other referrers, so it can ignore discard entry's reference count
> when removing the entry, otherwise in other caller we will hit bug_on
> in __remove_discard_cmd as there may be other issuer added reference
> count in discard entry.
>
> Thread A Thread B
> - issue_discard_thread
> - f2fs_ioc_fitrim
> - f2fs_trim_fs
> - f2fs_wait_discard_bios
> - __issue_discard_cmd
> - __submit_discard_cmd
> - __wait_discard_cmd
> - dc->ref++
> - __wait_one_discard_bio
> - __wait_discard_cmd
> - __remove_discard_cmd
> - f2fs_bug_on(sbi, dc->ref)
>
> Fixes: 969d1b180d987c2be02de890d0fff0f66a0e80de
> Reported-by: Ju Hyung Park <qkrwngud825@xxxxxxxxx>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> fs/f2fs/f2fs.h | 2 +-
> fs/f2fs/segment.c | 6 +++---
> fs/f2fs/super.c | 2 +-
> 3 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 9a7c90386947..4b4a72f392be 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2525,7 +2525,7 @@ void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr);
> bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr);
> void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new);
> void stop_discard_thread(struct f2fs_sb_info *sbi);
> -void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
> +void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi, bool umount);
> void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc);
> void release_discard_addrs(struct f2fs_sb_info *sbi);
> int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index dedf0209d820..e28245b7e44e 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1210,11 +1210,11 @@ void stop_discard_thread(struct f2fs_sb_info *sbi)
> }
>
> /* This comes from f2fs_put_super and f2fs_trim_fs */
> -void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
> +void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi, bool umount)
> {
> __issue_discard_cmd(sbi, false);
> __drop_discard_cmd(sbi);
> - __wait_discard_cmd(sbi, false);
> + __wait_discard_cmd(sbi, !umount);
> }
>
> static void mark_discard_range_all(struct f2fs_sb_info *sbi)
> @@ -2244,7 +2244,7 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
> }
> /* It's time to issue all the filed discards */
> mark_discard_range_all(sbi);
> - f2fs_wait_discard_bios(sbi);
> + f2fs_wait_discard_bios(sbi, false);
> out:
> range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
> return err;
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 89f61eb3d167..933c3d529e65 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -801,7 +801,7 @@ static void f2fs_put_super(struct super_block *sb)
> }
>
> /* be sure to wait for any on-going discard commands */
> - f2fs_wait_discard_bios(sbi);
> + f2fs_wait_discard_bios(sbi, true);
>
> if (f2fs_discard_en(sbi) && !sbi->discard_blks) {
> struct cp_control cpc = {
> --
> 2.14.1.145.gb3622a4ee
>
> On 2017/10/2 3:29, Ju Hyung Park wrote:
>> When 'fstrim' is called for manual trim, a BUG() can be triggered
>> randomly with this patch.
>>
>> I'm seeing this issue on both x86 Desktop and arm64 Android phone.
>>
>> On x86 Desktop, this was caused during Ubuntu boot-up. I have a
>> cronjob installed
>> which calls 'fstrim -v /' during boot.
>> On arm64 Android, this was caused during GC looping with
>> 1ms gc_min_sleep_time & gc_max_sleep_time.
>>
>> Thanks.
>>
>> [26671.666421] ------------[ cut here ]------------
>> [26671.666426] WARNING: CPU: 8 PID: 103479 at fs/f2fs/segment.c:797
>> __remove_discard_cmd+0xb9/0xd0
>> [26671.666427] Modules linked in: ftdi_sio usbserial uas usb_storage
>> vmnet(O) vmw_vsock_vmci_transport vsock vmw_vmci vmmon(O) rfcomm
>> xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4
>> iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4
>> xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge
>> stp llc bnep ebtable_filter ebtables ip6table_filter ip6_tables
>> xt_multiport iptable_filter binfmt_misc snd_hda_codec_hdmi eeepc_wmi
>> asus_wmi sparse_keymap video wmi_bmof mxm_wmi nls_iso8859_1 btusb
>> btrtl joydev btbcm btintel input_leds bluetooth edac_mce_amd
>> snd_hda_codec_realtek snd_hda_codec_generic kvm_amd kvm irqbypass
>> snd_seq_dummy snd_hda_intel snd_hda_codec snd_seq_oss snd_seq_midi
>> snd_hda_core snd_seq_midi_event snd_hwdep snd_pcm snd_rawmidi snd_seq
>> snd_seq_device
>> [26671.666450] snd_timer snd soundcore k10temp i2c_piix4
>> nvidia_uvm(PO) shpchp wmi 8250_dw mac_hid parport_pc ppdev nfsd lp
>> auth_rpcgss parport oid_registry nfs_acl lockd grace sunrpc ip_tables
>> x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy
>> async_pq async_xor async_tx raid1 multipath linear hid_generic
>> hid_apple usbhid nvidia_drm(PO) nvidia_modeset(PO) nvidia(PO)
>> drm_kms_helper syscopyarea sysfillrect sysimgblt igb fb_sys_fops dca
>> ptp drm pps_core i2c_algo_bit ahci libahci gpio_amdpt gpio_generic
>> [26671.666471] CPU: 8 PID: 103479 Comm: fstrim Tainted: P O
>> 4.13.4-zen+ #1
>> [26671.666472] Hardware name: System manufacturer System Product
>> Name/PRIME X399-A, BIOS 0318 08/11/2017
>> [26671.666472] task: ffff8804ad535800 task.stack: ffff88047ee38000
>> [26671.666474] RIP: 0010:__remove_discard_cmd+0xb9/0xd0
>> [26671.666474] RSP: 0018:ffff88047ee3bd00 EFLAGS: 00010202
>> [26671.666475] RAX: ffff88081801a500 RBX: ffff88047eeaed00 RCX: ffff88047eeaedf8
>> [26671.666475] RDX: 0000000000000001 RSI: ffff88047eeaed00 RDI: ffff880802555800
>> [26671.666476] RBP: ffff8808134d0000 R08: ffff8804ad535800 R09: 0000000000000001
>> [26671.666476] R10: ffff88047ee3bd18 R11: 0000000000000000 R12: ffff880802555800
>> [26671.666476] R13: 0000000000000000 R14: ffff88047eeaedd0 R15: ffff8808134d0000
>> [26671.666477] FS: 00007f44cddad2c0(0000) GS:ffff88081ca00000(0000)
>> knlGS:0000000000000000
>> [26671.666478] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [26671.666478] CR2: 00007f88f5776328 CR3: 000000058ce4a000 CR4: 00000000003406e0
>> [26671.666479] Call Trace:
>> [26671.666481] ? __wait_discard_cmd+0x7a/0xc0
>> [26671.666482] ? f2fs_trim_fs+0x1c1/0x210
>> [26671.666484] ? f2fs_ioctl+0x75a/0x2320
>> [26671.666486] ? do_filp_open+0x99/0xe0
>> [26671.666487] ? cp_new_stat+0x138/0x150
>> [26671.666489] ? do_vfs_ioctl+0x88/0x5c0
>> [26671.666490] ? SyS_newfstat+0x29/0x40
>> [26671.666491] ? SyS_ioctl+0x6f/0x80
>> [26671.666493] ? entry_SYSCALL_64_fastpath+0x1e/0xa9
>> [26671.666493] Code: 48 89 de 8b 43 1c 48 8b 3d 4d 8c 31 01 29 85 74
>> 22 00 00 e8 fa 01 d5 ff f0 ff 8d 80 22 00 00 5b 5d c3 c7 43 64 00 00
>> 00 00 eb 92 <0f> ff f0 80 4f 20 04 e9 53 ff ff ff 90 66 2e 0f 1f 84 00
>> 00 00
>> [26671.666506] ---[ end trace 613553f7a4728b5a ]---
>> [26672.553742] general protection fault: 0000 [#1] PREEMPT SMP
>> [26672.553746] Modules linked in: ftdi_sio usbserial uas usb_storage
>> vmnet(O) vmw_vsock_vmci_transport vsock vmw_vmci vmmon(O) rfcomm
>> xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4
>> iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4
>> xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge
>> stp llc bnep ebtable_filter ebtables ip6table_filter ip6_tables
>> xt_multiport iptable_filter binfmt_misc snd_hda_codec_hdmi eeepc_wmi
>> asus_wmi sparse_keymap video wmi_bmof mxm_wmi nls_iso8859_1 btusb
>> btrtl joydev btbcm btintel input_leds bluetooth edac_mce_amd
>> snd_hda_codec_realtek snd_hda_codec_generic kvm_amd kvm irqbypass
>> snd_seq_dummy snd_hda_intel snd_hda_codec snd_seq_oss snd_seq_midi
>> snd_hda_core snd_seq_midi_event snd_hwdep snd_pcm snd_rawmidi snd_seq
>> snd_seq_device
>> [26672.553771] snd_timer snd soundcore k10temp i2c_piix4
>> nvidia_uvm(PO) shpchp wmi 8250_dw mac_hid parport_pc ppdev nfsd lp
>> auth_rpcgss parport oid_registry nfs_acl lockd grace sunrpc ip_tables
>> x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy
>> async_pq async_xor async_tx raid1 multipath linear hid_generic
>> hid_apple usbhid nvidia_drm(PO) nvidia_modeset(PO) nvidia(PO)
>> drm_kms_helper syscopyarea sysfillrect sysimgblt igb fb_sys_fops dca
>> ptp drm pps_core i2c_algo_bit ahci libahci gpio_amdpt gpio_generic
>> [26672.553792] CPU: 10 PID: 1287 Comm: f2fs_discard-25 Tainted: P
>> W O 4.13.4-zen+ #1
>> [26672.553793] Hardware name: System manufacturer System Product
>> Name/PRIME X399-A, BIOS 0318 08/11/2017
>> [26672.553794] task: ffff8808159c1600 task.stack: ffff880813304000
>> [26672.553798] RIP: 0010:__remove_discard_cmd+0x6a/0xd0
>> [26672.553799] RSP: 0018:ffff880813307e20 EFLAGS: 00010296
>> [26672.553800] RAX: dead000000000200 RBX: ffff88047eeaed00 RCX: ffff8808159c1601
>> [26672.553801] RDX: dead000000000100 RSI: ffff8808134d2288 RDI: ffff88047eeaed00
>> [26672.553801] RBP: ffff8808134d0000 R08: 0000184230172c00 R09: 0000000000000006
>> [26672.553802] R10: ffff880813307e38 R11: 0000000000000023 R12: ffff880802555800
>> [26672.553803] R13: 0000000000000001 R14: ffff88047eeaed00 R15: ffff8808134d0000
>> [26672.553804] FS: 0000000000000000(0000) GS:ffff88081ca80000(0000)
>> knlGS:0000000000000000
>> [26672.553805] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [26672.553805] CR2: 00007f88f2f71328 CR3: 000000048be79000 CR4: 00000000003406e0
>> [26672.553806] Call Trace:
>> [26672.553808] ? __wait_one_discard_bio+0x41/0x60
>> [26672.553809] ? __wait_discard_cmd+0xbb/0xc0
>> [26672.553811] ? issue_discard_thread+0x196/0x200
>> [26672.553813] ? wait_woken+0x80/0x80
>> [26672.553814] ? mark_discard_range_all.isra.11+0x40/0x40
>> [26672.553816] ? kthread+0x112/0x130
>> [26672.553817] ? kthread_create_on_node+0x40/0x40
>> [26672.553818] ? do_group_exit+0x2e/0xa0
>> [26672.553820] ? ret_from_fork+0x25/0x30
>> [26672.553821] Code: 8b 43 20 48 8b 3f e8 56 6c fe ff 58 80 7b 62 02
>> 75 07 f0 ff 8d 7c 22 00 00 48 8b 53 28 48 8b 43 30 48 8d b5 88 22 00
>> 00 48 89 df <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89
>> 43 28
>> [26672.553835] RIP: __remove_discard_cmd+0x6a/0xd0 RSP: ffff880813307e20
>> [26672.553836] ---[ end trace 613553f7a4728b5b ]---
>>
>> On Tue, Aug 22, 2017 at 5:42 AM, Jaegeuk Kim <jaegeuk@xxxxxxxxxx> wrote:
>>> On 08/18, Chao Yu wrote:
>>>> Hi Jaegeuk,
>>>>
>>>> Sorry for the delay, the modification looks good to me. ;)
>>>
>>> We must avoid waking up discard thread caused by # of pending commands
>>> which are never issued.
>>>
>>> From a73f8807248c2f42328a2204eab16a3b8d32c83e Mon Sep 17 00:00:00 2001
>>> From: Chao Yu <yuchao0@xxxxxxxxxx>
>>> Date: Mon, 7 Aug 2017 23:09:56 +0800
>>> Subject: [PATCH] f2fs: introduce discard_granularity sysfs entry
>>>
>>> Commit d618ebaf0aa8 ("f2fs: enable small discard by default") enables
>>> f2fs to issue 4K size discard in real-time discard mode. However, issuing
>>> smaller discard may cost more lifetime but releasing less free space in
>>> flash device. Since f2fs has ability of separating hot/cold data and
>>> garbage collection, we can expect that small-sized invalid region would
>>> expand soon with OPU, deletion or garbage collection on valid datas, so
>>> it's better to delay or skip issuing smaller size discards, it could help
>>> to reduce overmuch consumption of IO bandwidth and lifetime of flash
>>> storage.
>>>
>>> This patch makes f2fs selectng 64K size as its default minimal
>>> granularity, and issue discard with the size which is not smaller than
>>> minimal granularity. Also it exposes discard granularity as sysfs entry
>>> for configuration in different scenario.
>>>
>>> Jaegeuk Kim:
>>> We must issue all the accumulated discard commands when fstrim is called.
>>> So, I've added pend_list_tag[] to indicate whether we should issue the
>>> commands or not. If tag sets P_ACTIVE or P_TRIM, we have to issue them.
>>> P_TRIM is set once at a time, given fstrim trigger.
>>> In addition, issue_discard_thread is calling too much due to the number of
>>> discard commands remaining in the pending list. I added a timer to control
>>> it likewise gc_thread.
>>>
>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
>>> ---
>>> Documentation/ABI/testing/sysfs-fs-f2fs | 9 ++++
>>> fs/f2fs/f2fs.h | 12 +++++
>>> fs/f2fs/segment.c | 91 ++++++++++++++++++++++++++++-----
>>> fs/f2fs/sysfs.c | 23 +++++++++
>>> 4 files changed, 121 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
>>> index 621da3fc56c5..11b7f4ebea7c 100644
>>> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
>>> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
>>> @@ -57,6 +57,15 @@ Contact: "Jaegeuk Kim" <jaegeuk.kim@xxxxxxxxxxx>
>>> Description:
>>> Controls the issue rate of small discard commands.
>>>
>>> +What: /sys/fs/f2fs/<disk>/discard_granularity
>>> +Date: July 2017
>>> +Contact: "Chao Yu" <yuchao0@xxxxxxxxxx>
>>> +Description:
>>> + Controls discard granularity of inner discard thread, inner thread
>>> + will not issue discards with size that is smaller than granularity.
>>> + The unit size is one block, now only support configuring in range
>>> + of [1, 512].
>>> +
>>> What: /sys/fs/f2fs/<disk>/max_victim_search
>>> Date: January 2014
>>> Contact: "Jaegeuk Kim" <jaegeuk.kim@xxxxxxxxxxx>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index e252e5bf9791..4b993961d81d 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -148,6 +148,8 @@ enum {
>>> (BATCHED_TRIM_SEGMENTS(sbi) << (sbi)->log_blocks_per_seg)
>>> #define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi)
>>> #define DISCARD_ISSUE_RATE 8
>>> +#define DEF_MIN_DISCARD_ISSUE_TIME 50 /* 50 ms, if exists */
>>> +#define DEF_MAX_DISCARD_ISSUE_TIME 60000 /* 60 s, if no candidates */
>>> #define DEF_CP_INTERVAL 60 /* 60 secs */
>>> #define DEF_IDLE_INTERVAL 5 /* 5 secs */
>>>
>>> @@ -196,11 +198,18 @@ struct discard_entry {
>>> unsigned char discard_map[SIT_VBLOCK_MAP_SIZE]; /* segment discard bitmap */
>>> };
>>>
>>> +/* default discard granularity of inner discard thread, unit: block count */
>>> +#define DEFAULT_DISCARD_GRANULARITY 16
>>> +
>>> /* max discard pend list number */
>>> #define MAX_PLIST_NUM 512
>>> #define plist_idx(blk_num) ((blk_num) >= MAX_PLIST_NUM ? \
>>> (MAX_PLIST_NUM - 1) : (blk_num - 1))
>>>
>>> +#define P_ACTIVE 0x01
>>> +#define P_TRIM 0x02
>>> +#define plist_issue(tag) (((tag) & P_ACTIVE) || ((tag) & P_TRIM))
>>> +
>>> enum {
>>> D_PREP,
>>> D_SUBMIT,
>>> @@ -236,11 +245,14 @@ struct discard_cmd_control {
>>> struct task_struct *f2fs_issue_discard; /* discard thread */
>>> struct list_head entry_list; /* 4KB discard entry list */
>>> struct list_head pend_list[MAX_PLIST_NUM];/* store pending entries */
>>> + unsigned char pend_list_tag[MAX_PLIST_NUM];/* tag for pending entries */
>>> struct list_head wait_list; /* store on-flushing entries */
>>> wait_queue_head_t discard_wait_queue; /* waiting queue for wake-up */
>>> + unsigned int discard_wake; /* to wake up discard thread */
>>> struct mutex cmd_lock;
>>> unsigned int nr_discards; /* # of discards in the list */
>>> unsigned int max_discards; /* max. discards to be issued */
>>> + unsigned int discard_granularity; /* discard granularity */
>>> unsigned int undiscard_blks; /* # of undiscard blocks */
>>> atomic_t issued_discard; /* # of issued discard */
>>> atomic_t issing_discard; /* # of issing discard */
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 05144b3a7f62..1387925a0d83 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -1016,32 +1016,65 @@ static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
>>> return 0;
>>> }
>>>
>>> -static void __issue_discard_cmd(struct f2fs_sb_info *sbi, bool issue_cond)
>>> +static int __issue_discard_cmd(struct f2fs_sb_info *sbi, bool issue_cond)
>>> {
>>> struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> struct list_head *pend_list;
>>> struct discard_cmd *dc, *tmp;
>>> struct blk_plug plug;
>>> - int i, iter = 0;
>>> + int iter = 0, issued = 0;
>>> + int i;
>>>
>>> mutex_lock(&dcc->cmd_lock);
>>> f2fs_bug_on(sbi,
>>> !__check_rb_tree_consistence(sbi, &dcc->root));
>>> blk_start_plug(&plug);
>>> - for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
>>> + for (i = MAX_PLIST_NUM - 1;
>>> + i >= 0 && plist_issue(dcc->pend_list_tag[i]); i--) {
>>> pend_list = &dcc->pend_list[i];
>>> list_for_each_entry_safe(dc, tmp, pend_list, list) {
>>> f2fs_bug_on(sbi, dc->state != D_PREP);
>>>
>>> - if (!issue_cond || is_idle(sbi))
>>> + /* Hurry up to finish fstrim */
>>> + if (dcc->pend_list_tag[i] & P_TRIM) {
>>> + __submit_discard_cmd(sbi, dc);
>>> + issued++;
>>> + continue;
>>> + }
>>> +
>>> + if (!issue_cond || is_idle(sbi)) {
>>> + issued++;
>>> __submit_discard_cmd(sbi, dc);
>>> + }
>>> if (issue_cond && iter++ > DISCARD_ISSUE_RATE)
>>> goto out;
>>> }
>>> + if (list_empty(pend_list) && dcc->pend_list_tag[i] & P_TRIM)
>>> + dcc->pend_list_tag[i] &= (~P_TRIM);
>>> }
>>> out:
>>> blk_finish_plug(&plug);
>>> mutex_unlock(&dcc->cmd_lock);
>>> +
>>> + return issued;
>>> +}
>>> +
>>> +static void __drop_discard_cmd(struct f2fs_sb_info *sbi)
>>> +{
>>> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> + struct list_head *pend_list;
>>> + struct discard_cmd *dc, *tmp;
>>> + int i;
>>> +
>>> + mutex_lock(&dcc->cmd_lock);
>>> + for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
>>> + pend_list = &dcc->pend_list[i];
>>> + list_for_each_entry_safe(dc, tmp, pend_list, list) {
>>> + f2fs_bug_on(sbi, dc->state != D_PREP);
>>> + __remove_discard_cmd(sbi, dc);
>>> + }
>>> + }
>>> + mutex_unlock(&dcc->cmd_lock);
>>> }
>>>
>>> static void __wait_one_discard_bio(struct f2fs_sb_info *sbi,
>>> @@ -1126,34 +1159,56 @@ void stop_discard_thread(struct f2fs_sb_info *sbi)
>>> void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
>>> {
>>> __issue_discard_cmd(sbi, false);
>>> + __drop_discard_cmd(sbi);
>>> __wait_discard_cmd(sbi, false);
>>> }
>>>
>>> +static void mark_discard_range_all(struct f2fs_sb_info *sbi)
>>> +{
>>> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> + int i;
>>> +
>>> + mutex_lock(&dcc->cmd_lock);
>>> + for (i = 0; i < MAX_PLIST_NUM; i++)
>>> + dcc->pend_list_tag[i] |= P_TRIM;
>>> + mutex_unlock(&dcc->cmd_lock);
>>> +}
>>> +
>>> static int issue_discard_thread(void *data)
>>> {
>>> struct f2fs_sb_info *sbi = data;
>>> struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> wait_queue_head_t *q = &dcc->discard_wait_queue;
>>> + unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME;
>>> + int issued;
>>>
>>> set_freezable();
>>>
>>> do {
>>> - wait_event_interruptible(*q, kthread_should_stop() ||
>>> - freezing(current) ||
>>> - atomic_read(&dcc->discard_cmd_cnt));
>>> + wait_event_interruptible_timeout(*q,
>>> + kthread_should_stop() || freezing(current) ||
>>> + dcc->discard_wake,
>>> + msecs_to_jiffies(wait_ms));
>>> if (try_to_freeze())
>>> continue;
>>> if (kthread_should_stop())
>>> return 0;
>>>
>>> + if (dcc->discard_wake)
>>> + dcc->discard_wake = 0;
>>> +
>>> sb_start_intwrite(sbi->sb);
>>>
>>> - __issue_discard_cmd(sbi, true);
>>> - __wait_discard_cmd(sbi, true);
>>> + issued = __issue_discard_cmd(sbi, true);
>>> + if (issued) {
>>> + __wait_discard_cmd(sbi, true);
>>> + wait_ms = DEF_MIN_DISCARD_ISSUE_TIME;
>>> + } else {
>>> + wait_ms = DEF_MAX_DISCARD_ISSUE_TIME;
>>> + }
>>>
>>> sb_end_intwrite(sbi->sb);
>>>
>>> - congestion_wait(BLK_RW_SYNC, HZ/50);
>>> } while (!kthread_should_stop());
>>> return 0;
>>> }
>>> @@ -1344,7 +1399,8 @@ static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
>>>
>>> void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>>> {
>>> - struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
>>> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> + struct list_head *head = &dcc->entry_list;
>>> struct discard_entry *entry, *this;
>>> struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
>>> unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
>>> @@ -1426,11 +1482,12 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>>> goto find_next;
>>>
>>> list_del(&entry->list);
>>> - SM_I(sbi)->dcc_info->nr_discards -= total_len;
>>> + dcc->nr_discards -= total_len;
>>> kmem_cache_free(discard_entry_slab, entry);
>>> }
>>>
>>> - wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
>>> + dcc->discard_wake = 1;
>>> + wake_up_interruptible_all(&dcc->discard_wait_queue);
>>> }
>>>
>>> static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
>>> @@ -1448,9 +1505,13 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
>>> if (!dcc)
>>> return -ENOMEM;
>>>
>>> + dcc->discard_granularity = DEFAULT_DISCARD_GRANULARITY;
>>> INIT_LIST_HEAD(&dcc->entry_list);
>>> - for (i = 0; i < MAX_PLIST_NUM; i++)
>>> + for (i = 0; i < MAX_PLIST_NUM; i++) {
>>> INIT_LIST_HEAD(&dcc->pend_list[i]);
>>> + if (i >= dcc->discard_granularity - 1)
>>> + dcc->pend_list_tag[i] |= P_ACTIVE;
>>> + }
>>> INIT_LIST_HEAD(&dcc->wait_list);
>>> mutex_init(&dcc->cmd_lock);
>>> atomic_set(&dcc->issued_discard, 0);
>>> @@ -2127,6 +2188,8 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
>>>
>>> schedule();
>>> }
>>> + /* It's time to issue all the filed discards */
>>> + mark_discard_range_all(sbi);
>>> out:
>>> range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
>>> return err;
>>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>>> index c40e5d24df9f..4bcaa9059026 100644
>>> --- a/fs/f2fs/sysfs.c
>>> +++ b/fs/f2fs/sysfs.c
>>> @@ -152,6 +152,27 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
>>> spin_unlock(&sbi->stat_lock);
>>> return count;
>>> }
>>> +
>>> + if (!strcmp(a->attr.name, "discard_granularity")) {
>>> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>> + int i;
>>> +
>>> + if (t == 0 || t > MAX_PLIST_NUM)
>>> + return -EINVAL;
>>> + if (t == *ui)
>>> + return count;
>>> +
>>> + mutex_lock(&dcc->cmd_lock);
>>> + for (i = 0; i < MAX_PLIST_NUM; i++) {
>>> + if (i >= t - 1)
>>> + dcc->pend_list_tag[i] |= P_ACTIVE;
>>> + else
>>> + dcc->pend_list_tag[i] &= (~P_ACTIVE);
>>> + }
>>> + mutex_unlock(&dcc->cmd_lock);
>>> + return count;
>>> + }
>>> +
>>> *ui = t;
>>>
>>> if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
>>> @@ -248,6 +269,7 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
>>> F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent, gc_urgent);
>>> F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
>>> F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
>>> +F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
>>> F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
>>> F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
>>> F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
>>> @@ -290,6 +312,7 @@ static struct attribute *f2fs_attrs[] = {
>>> ATTR_LIST(gc_urgent),
>>> ATTR_LIST(reclaim_segments),
>>> ATTR_LIST(max_small_discards),
>>> + ATTR_LIST(discard_granularity),
>>> ATTR_LIST(batched_trim_sections),
>>> ATTR_LIST(ipu_policy),
>>> ATTR_LIST(min_ipu_util),
>>> --
>>> 2.14.0.rc1.383.gd1ce394fe2-goog
>>>
>>>
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>>> _______________________________________________
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>>> Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
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