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Commit | Line | Data |
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5da6072d AM |
1 | From: Shaohua Li <shli@fb.com> |
2 | ||
3 | Basically this is a copy of commit 001e4a8775f6(ext4: implement cgroup | |
4 | writeback support). Tested with a fio test, verified writeback is | |
5 | throttled against cgroup io.max write bandwidth, also verified moving | |
6 | the fio test to another cgroup and the writeback is throttled against | |
7 | new cgroup setting. | |
8 | ||
9 | Cc: Tejun Heo <tj@kernel.org> | |
10 | Signed-off-by: Shaohua Li <shli@fb.com> | |
11 | --- | |
12 | fs/xfs/xfs_aops.c | 2 ++ | |
13 | fs/xfs/xfs_super.c | 1 + | |
14 | 2 files changed, 3 insertions(+) | |
15 | ||
679d237f AM |
16 | --- linux-4.19/fs/xfs/xfs_aops.c.org 2018-11-21 10:31:12.348955352 +0100 |
17 | +++ linux-4.19/fs/xfs/xfs_aops.c 2018-11-21 10:34:35.241764742 +0100 | |
5da6072d AM |
18 | @@ -613,8 +613,10 @@ xfs_add_to_ioend( |
19 | list_add(&wpc->ioend->io_list, iolist); | |
20 | wpc->ioend = xfs_alloc_ioend(inode, wpc->io_type, offset, | |
21 | bdev, sector); | |
22 | + wbc_init_bio(wbc, wpc->ioend->io_bio); | |
23 | } | |
24 | ||
679d237f | 25 | + wbc_account_io(wbc, page, len); |
5da6072d AM |
26 | if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff)) { |
27 | if (iop) | |
28 | atomic_inc(&iop->write_count); | |
29 | diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c | |
30 | index 584cf2d..aea3bc2 100644 | |
31 | --- a/fs/xfs/xfs_super.c | |
32 | +++ b/fs/xfs/xfs_super.c | |
33 | @@ -1634,6 +1634,7 @@ xfs_fs_fill_super( | |
34 | sb->s_max_links = XFS_MAXLINK; | |
35 | sb->s_time_gran = 1; | |
36 | set_posix_acl_flag(sb); | |
37 | + sb->s_iflags |= SB_I_CGROUPWB; | |
38 | ||
39 | /* version 5 superblocks support inode version counters. */ | |
40 | if (XFS_SB_VERSION_NUM(&mp->m_sb) == XFS_SB_VERSION_5) | |
8b5fc054 AM |
41 | From e820d55cb99dd93ac2dc949cf486bb187e5cd70d Mon Sep 17 00:00:00 2001 |
42 | From: Guoqing Jiang <gqjiang@suse.com> | |
43 | Date: Wed, 19 Dec 2018 14:19:25 +0800 | |
44 | Subject: md: fix raid10 hang issue caused by barrier | |
45 | MIME-Version: 1.0 | |
46 | Content-Type: text/plain; charset=UTF-8 | |
47 | Content-Transfer-Encoding: 8bit | |
48 | ||
49 | When both regular IO and resync IO happen at the same time, | |
50 | and if we also need to split regular. Then we can see tasks | |
51 | hang due to barrier. | |
52 | ||
53 | 1. resync thread | |
54 | [ 1463.757205] INFO: task md1_resync:5215 blocked for more than 480 seconds. | |
55 | [ 1463.757207] Not tainted 4.19.5-1-default #1 | |
56 | [ 1463.757209] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. | |
57 | [ 1463.757212] md1_resync D 0 5215 2 0x80000000 | |
58 | [ 1463.757216] Call Trace: | |
59 | [ 1463.757223] ? __schedule+0x29a/0x880 | |
60 | [ 1463.757231] ? raise_barrier+0x8d/0x140 [raid10] | |
61 | [ 1463.757236] schedule+0x78/0x110 | |
62 | [ 1463.757243] raise_barrier+0x8d/0x140 [raid10] | |
63 | [ 1463.757248] ? wait_woken+0x80/0x80 | |
64 | [ 1463.757257] raid10_sync_request+0x1f6/0x1e30 [raid10] | |
65 | [ 1463.757265] ? _raw_spin_unlock_irq+0x22/0x40 | |
66 | [ 1463.757284] ? is_mddev_idle+0x125/0x137 [md_mod] | |
67 | [ 1463.757302] md_do_sync.cold.78+0x404/0x969 [md_mod] | |
68 | [ 1463.757311] ? wait_woken+0x80/0x80 | |
69 | [ 1463.757336] ? md_rdev_init+0xb0/0xb0 [md_mod] | |
70 | [ 1463.757351] md_thread+0xe9/0x140 [md_mod] | |
71 | [ 1463.757358] ? _raw_spin_unlock_irqrestore+0x2e/0x60 | |
72 | [ 1463.757364] ? __kthread_parkme+0x4c/0x70 | |
73 | [ 1463.757369] kthread+0x112/0x130 | |
74 | [ 1463.757374] ? kthread_create_worker_on_cpu+0x40/0x40 | |
75 | [ 1463.757380] ret_from_fork+0x3a/0x50 | |
76 | ||
77 | 2. regular IO | |
78 | [ 1463.760679] INFO: task kworker/0:8:5367 blocked for more than 480 seconds. | |
79 | [ 1463.760683] Not tainted 4.19.5-1-default #1 | |
80 | [ 1463.760684] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. | |
81 | [ 1463.760687] kworker/0:8 D 0 5367 2 0x80000000 | |
82 | [ 1463.760718] Workqueue: md submit_flushes [md_mod] | |
83 | [ 1463.760721] Call Trace: | |
84 | [ 1463.760731] ? __schedule+0x29a/0x880 | |
85 | [ 1463.760741] ? wait_barrier+0xdd/0x170 [raid10] | |
86 | [ 1463.760746] schedule+0x78/0x110 | |
87 | [ 1463.760753] wait_barrier+0xdd/0x170 [raid10] | |
88 | [ 1463.760761] ? wait_woken+0x80/0x80 | |
89 | [ 1463.760768] raid10_write_request+0xf2/0x900 [raid10] | |
90 | [ 1463.760774] ? wait_woken+0x80/0x80 | |
91 | [ 1463.760778] ? mempool_alloc+0x55/0x160 | |
92 | [ 1463.760795] ? md_write_start+0xa9/0x270 [md_mod] | |
93 | [ 1463.760801] ? try_to_wake_up+0x44/0x470 | |
94 | [ 1463.760810] raid10_make_request+0xc1/0x120 [raid10] | |
95 | [ 1463.760816] ? wait_woken+0x80/0x80 | |
96 | [ 1463.760831] md_handle_request+0x121/0x190 [md_mod] | |
97 | [ 1463.760851] md_make_request+0x78/0x190 [md_mod] | |
98 | [ 1463.760860] generic_make_request+0x1c6/0x470 | |
99 | [ 1463.760870] raid10_write_request+0x77a/0x900 [raid10] | |
100 | [ 1463.760875] ? wait_woken+0x80/0x80 | |
101 | [ 1463.760879] ? mempool_alloc+0x55/0x160 | |
102 | [ 1463.760895] ? md_write_start+0xa9/0x270 [md_mod] | |
103 | [ 1463.760904] raid10_make_request+0xc1/0x120 [raid10] | |
104 | [ 1463.760910] ? wait_woken+0x80/0x80 | |
105 | [ 1463.760926] md_handle_request+0x121/0x190 [md_mod] | |
106 | [ 1463.760931] ? _raw_spin_unlock_irq+0x22/0x40 | |
107 | [ 1463.760936] ? finish_task_switch+0x74/0x260 | |
108 | [ 1463.760954] submit_flushes+0x21/0x40 [md_mod] | |
109 | ||
110 | So resync io is waiting for regular write io to complete to | |
111 | decrease nr_pending (conf->barrier++ is called before waiting). | |
112 | The regular write io splits another bio after call wait_barrier | |
113 | which call nr_pending++, then the splitted bio would continue | |
114 | with raid10_write_request -> wait_barrier, so the splitted bio | |
115 | has to wait for barrier to be zero, then deadlock happens as | |
116 | follows. | |
117 | ||
118 | resync io regular io | |
119 | ||
120 | raise_barrier | |
121 | wait_barrier | |
122 | generic_make_request | |
123 | wait_barrier | |
124 | ||
125 | To resolve the issue, we need to call allow_barrier to decrease | |
126 | nr_pending before generic_make_request since regular IO is not | |
127 | issued to underlying devices, and wait_barrier is called again | |
128 | to ensure no internal IO happening. | |
129 | ||
130 | Fixes: fc9977dd069e ("md/raid10: simplify the splitting of requests.") | |
131 | Reported-and-tested-by: Siniša Bandin <sinisa@4net.rs> | |
132 | Signed-off-by: Guoqing Jiang <gqjiang@suse.com> | |
133 | Signed-off-by: Shaohua Li <shli@fb.com> | |
134 | --- | |
135 | drivers/md/raid10.c | 4 ++++ | |
136 | 1 file changed, 4 insertions(+) | |
137 | ||
138 | diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c | |
139 | index 76c92e31afc0..abb5d382f64d 100644 | |
140 | --- a/drivers/md/raid10.c | |
141 | +++ b/drivers/md/raid10.c | |
142 | @@ -1209,7 +1209,9 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, | |
143 | struct bio *split = bio_split(bio, max_sectors, | |
144 | gfp, &conf->bio_split); | |
145 | bio_chain(split, bio); | |
146 | + allow_barrier(conf); | |
147 | generic_make_request(bio); | |
148 | + wait_barrier(conf); | |
149 | bio = split; | |
150 | r10_bio->master_bio = bio; | |
151 | r10_bio->sectors = max_sectors; | |
152 | @@ -1492,7 +1494,9 @@ retry_write: | |
153 | struct bio *split = bio_split(bio, r10_bio->sectors, | |
154 | GFP_NOIO, &conf->bio_split); | |
155 | bio_chain(split, bio); | |
156 | + allow_barrier(conf); | |
157 | generic_make_request(bio); | |
158 | + wait_barrier(conf); | |
159 | bio = split; | |
160 | r10_bio->master_bio = bio; | |
161 | } | |
162 | -- | |
163 | cgit 1.2-0.3.lf.el7 | |
164 | ||
18976fa6 | 165 |