From: <gregkh@linuxfoundation.org>
To: <wenqing.lz@taobao.com>
Cc: <stable@vger.kernel.org>, <stable-commits@vger.kernel.org>
Subject: Patch "bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device" has been added to the 3.14-stable tree
Date: Tue, 01 Mar 2016 05:38:58 +0000 [thread overview]
Message-ID: <145681073884246@kroah.com> (raw)
This is a note to let you know that I've just added the patch titled
bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bcache-clear-bcache_dev_unlink_done-flag-when-attaching-a-backing-device.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From fecaee6f20ee122ad75402c53d8278f9bb142ddc Mon Sep 17 00:00:00 2001
From: Zheng Liu <wenqing.lz@taobao.com>
Date: Sun, 29 Nov 2015 17:19:32 -0800
Subject: bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device
From: Zheng Liu <wenqing.lz@taobao.com>
commit fecaee6f20ee122ad75402c53d8278f9bb142ddc upstream.
This bug can be reproduced by the following script:
#!/bin/bash
bcache_sysfs="/sys/fs/bcache"
function clear_cache()
{
if [ ! -e $bcache_sysfs ]; then
echo "no bcache sysfs"
exit
fi
cset_uuid=$(ls -l $bcache_sysfs|head -n 2|tail -n 1|awk '{print $9}')
sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/detach"
sleep 5
sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/attach"
}
for ((i=0;i<10;i++)); do
clear_cache
done
The warning messages look like below:
[ 275.948611] ------------[ cut here ]------------
[ 275.963840] WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xb8/0xd0() (Tainted: P W
--------------- )
[ 275.979253] Hardware name: Tecal RH2285
[ 275.994106] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:09.0/0000:08:00.0/host4/target4:2:1/4:2:1:0/block/sdb/sdb1/bcache/cache'
[ 276.024105] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler
bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801
i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas
pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan]
[ 276.072643] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1
[ 276.089315] Call Trace:
[ 276.105801] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0
[ 276.122650] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50
[ 276.139361] [<ffffffff81205c08>] ? sysfs_add_one+0xb8/0xd0
[ 276.156012] [<ffffffff8120609b>] ? sysfs_do_create_link+0x12b/0x170
[ 276.172682] [<ffffffff81206113>] ? sysfs_create_link+0x13/0x20
[ 276.189282] [<ffffffffa03bda21>] ? bcache_device_link+0xc1/0x110 [bcache]
[ 276.205993] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[ 276.222794] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache]
[ 276.239680] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110
[ 276.256594] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170
[ 276.273364] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0
[ 276.290133] [<ffffffff811890b1>] ? sys_write+0x51/0x90
[ 276.306368] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b
[ 276.322301] ---[ end trace 9f5d4fcdd0c3edfb ]---
[ 276.338241] ------------[ cut here ]------------
[ 276.354109] WARNING: at /home/wenqing.lz/bcache/bcache/super.c:720
bcache_device_link+0xdf/0x110 [bcache]() (Tainted: P W --------------- )
[ 276.386017] Hardware name: Tecal RH2285
[ 276.401430] Couldn't create device <-> cache set symlinks
[ 276.401759] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler
bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801
i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas
pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan]
[ 276.465477] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1
[ 276.482169] Call Trace:
[ 276.498610] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0
[ 276.515405] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50
[ 276.532059] [<ffffffffa03bda3f>] ? bcache_device_link+0xdf/0x110 [bcache]
[ 276.548808] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[ 276.565569] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache]
[ 276.582418] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110
[ 276.599341] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170
[ 276.616142] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0
[ 276.632607] [<ffffffff811890b1>] ? sys_write+0x51/0x90
[ 276.648671] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b
[ 276.664756] ---[ end trace 9f5d4fcdd0c3edfc ]---
We forget to clear BCACHE_DEV_UNLINK_DONE flag in bcache_device_attach()
function when we attach a backing device first time. After detaching this
backing device, this flag will be true and sysfs_remove_link() isn't called in
bcache_device_unlink(). Then when we attach this backing device again,
sysfs_create_link() will return EEXIST error in bcache_device_link().
So the fix is trival and we clear this flag in bcache_device_link().
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Tested-by: Joshua Schmid <jschmid@suse.com>
Tested-by: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/bcache/super.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -712,6 +712,8 @@ static void bcache_device_link(struct bc
WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
sysfs_create_link(&c->kobj, &d->kobj, d->name),
"Couldn't create device <-> cache set symlinks");
+
+ clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
}
static void bcache_device_detach(struct bcache_device *d)
Patches currently in stable-queue which might be from wenqing.lz@taobao.com are
queue-3.14/bcache-clear-bcache_dev_unlink_done-flag-when-attaching-a-backing-device.patch
queue-3.14/bcache-fix-a-livelock-when-we-cause-a-huge-number-of-cache-misses.patch
queue-3.14/bcache-unregister-reboot-notifier-if-bcache-fails-to-unregister-device.patch
reply other threads:[~2016-03-01 5:39 UTC|newest]
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