Subject:
Re: [PATCH] scsi: target: Fix data corruption under concurrent target
configuration
From:
Grzegorz Uriasz <gorbak25@xxxxxxxxx>
Date:
22/05/2023, 13:27
To:
Dmitry Bogdanov <d.bogdanov@xxxxxxxxx>
CC:
"Martin K. Petersen" <martin.petersen@xxxxxxxxxx>,
linux-scsi@xxxxxxxxxxxxxxx, target-devel@xxxxxxxxxxxxxxx,
linux-kernel@xxxxxxxxxxxxxxx, dutkahugo@xxxxxxxxx
Hi Dmitry,
I've added a debug printk call to see whether the devices are enabled
concurrently:
---
drivers/target/target_core_device.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/target/target_core_device.c
b/drivers/target/target_core_device.c
index 5054b647dd0b..f594ee86a986 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -910,6 +910,8 @@ int target_configure_device(struct se_device *dev)
return -EEXIST;
}
+ pr_err("Configuring %p device", dev);
+
/*
* Add early so modules like tcmu can use during its
* configuration.
--
2.40.0
It turns out that even when the flags are set atomically it seems that
there is either no mutex protecting the setup or concurrent kzalloc
calls returned the same address:
[ 3179.785908] kobject: 'maps' (000000000fdf10fd): calling ktype release
[ 3179.785910] kobject: (000000000fdf10fd): dynamic_kobj_release
[ 3179.785912] kobject: 'maps': free name
[ 3179.785953] tcmu nl cmd 2/0 completion could not find device with
dev id 87.
[ 3179.786015] kobject: 'uio8' (000000001b25d2de): kobject_uevent_env
[ 3179.786315] kobject: 'uio8' (000000001b25d2de): fill_kobj_path:
path = '/devices/tcm_user/uio/uio8'
[ 3179.786315] tcmu nl cmd 2/0 completion could not find device with
dev id 87.
[ 3179.786322] tcmu nl cmd 2/0 completion could not find device with
dev id 87.
[ 3179.786557] kobject: 'uio8' (000000001b25d2de): kobject_cleanup,
parent 0000000000000000
[ 3179.786902] kobject: 'uio8' (000000001b25d2de): calling ktype release
[ 3179.786904] kobject: 'uio8': free name
[ 3179.786906] tcmu nl cmd 2/0 completion could not find device with
dev id 87.
[ 3179.787226] tcmu nl cmd 2/0 completion could not find device with
dev id 87.
[ 3179.809906] kobject: 'map0' (000000003fa04166): kobject_cleanup,
parent 00000000e5849eec
[ 3179.809914] kobject: 'map0' (000000003fa04166): auto cleanup
kobject_del
[ 3179.809930] tcmu nl cmd 2/0 completion could not find device with
dev id 89.
[ 3179.809936] kobject: 'map0' (000000003fa04166): calling ktype release
[ 3179.810216] kobject: 'map0': free name
[ 3179.810218] tcmu nl cmd 2/0 completion could not find device with
dev id 89.
[ 3179.810219] kobject: 'maps' (00000000e5849eec): kobject_cleanup,
parent 00000000345aab09
[ 3179.810226] tcmu nl cmd 2/0 completion could not find device with
dev id 89.
[ 3179.810535] kobject: 'maps' (00000000e5849eec): auto cleanup
kobject_del
[ 3179.810890] tcmu nl cmd 2/0 completion could not find device with
dev id 89.
[ 3179.810890] kobject: 'maps' (00000000e5849eec): calling ktype release
[ 3179.811171] kobject: (00000000e5849eec): dynamic_kobj_release
[ 3179.811174] kobject: 'maps': free name
[ 3179.811195] tcmu nl cmd 2/0 completion could not find device with
dev id 89.
[ 3179.811292] kobject: 'uio9' (00000000345aab09): kobject_uevent_env
[ 3179.811546] kobject: 'uio9' (00000000345aab09): fill_kobj_path:
path = '/devices/tcm_user/uio/uio9'
[ 3179.811576] kobject: 'uio9' (00000000345aab09): kobject_cleanup,
parent 0000000000000000
[ 3179.811578] kobject: 'uio9' (00000000345aab09): calling ktype release
[ 3179.811581] kobject: 'uio9': free name
[ 3179.829730] kobject: '0' (00000000981718a9): kobject_cleanup,
parent 0000000000000000
[ 3179.829736] kobject: '0' (00000000981718a9): calling ktype release
[ 3179.829740] kobject: '0': free name
[ 3179.829743] kobject: 'cpu0' (00000000155d52b3): kobject_cleanup,
parent 0000000000000000
[ 3179.829744] kobject: 'cpu0' (00000000155d52b3): calling ktype release
[ 3179.829746] kobject: 'cpu0': free name
[ 3179.829751] kobject: 'cpu1' (0000000050648bc7): kobject_cleanup,
parent 0000000000000000
[ 3179.829753] kobject: 'cpu1' (0000000050648bc7): calling ktype release
[ 3179.829754] kobject: 'cpu1': free name
[ 3179.829755] kobject: 'cpu2' (00000000f0e72c5c): kobject_cleanup,
parent 0000000000000000
[ 3179.829757] kobject: 'cpu2' (00000000f0e72c5c): calling ktype release
[ 3179.829758] kobject: 'cpu2': free name
[ 3179.829759] kobject: 'cpu3' (000000000b256e81): kobject_cleanup,
parent 0000000000000000
[ 3179.829760] kobject: 'cpu3' (000000000b256e81): calling ktype release
[ 3179.829761] kobject: 'cpu3': free name
[ 3179.829762] kobject: 'cpu4' (000000008d489b4f): kobject_cleanup,
parent 0000000000000000
[ 3179.829764] kobject: 'cpu4' (000000008d489b4f): calling ktype release
[ 3179.829765] kobject: 'cpu4': free name
[ 3179.829766] kobject: 'cpu5' (00000000f2e35ad0): kobject_cleanup,
parent 0000000000000000
[ 3179.829767] kobject: 'cpu5' (00000000f2e35ad0): calling ktype release
[ 3179.829768] kobject: 'cpu5': free name
[ 3179.829769] kobject: 'cpu6' (00000000ecbd8737): kobject_cleanup,
parent 0000000000000000
[ 3179.829771] kobject: 'cpu6' (00000000ecbd8737): calling ktype release
[ 3179.829772] kobject: 'cpu6': free name
[ 3179.829773] kobject: 'cpu7' (00000000813ca063): kobject_cleanup,
parent 0000000000000000
[ 3179.829774] kobject: 'cpu7' (00000000813ca063): calling ktype release
[ 3179.829775] kobject: 'cpu7': free name
[ 3179.829776] kobject: 'mq' (0000000062154d34): kobject_cleanup,
parent 0000000000000000
[ 3179.829778] kobject: 'mq' (0000000062154d34): calling ktype release
[ 3179.829781] kobject: 'mq': free name
[ 3179.937204] tcmu daemon: command reply support 1.
[ 3180.242175] Configuring 0000000048576d33 device
[ 3180.242191] Configuring 00000000a24b9f12 device
[ 3180.243085] Configuring 0000000048576d33 device
[ 3180.243097] Configuring 0000000048576d33 device
[ 3180.243195] kobject: 'uio8' (00000000d48cde09):
kobject_add_internal: parent: 'uio', set: 'devices'
[ 3180.243293] kobject: 'uio8' (00000000d48cde09): kobject_uevent_env
[ 3180.243325] kobject: 'uio9' (0000000025c5cb20):
kobject_add_internal: parent: 'uio', set: 'devices'
[ 3180.243388] kobject: 'uio9' (0000000025c5cb20): kobject_uevent_env
[ 3180.243392] kobject: 'uio9' (0000000025c5cb20): fill_kobj_path:
path = '/devices/tcm_user/uio/uio9'
[ 3180.243419] kobject: 'maps' (000000007f057cf5):
kobject_add_internal: parent: 'uio9', set: '<NULL>'
[ 3180.243424] kobject: 'map0' (00000000f663b250):
kobject_add_internal: parent: 'maps', set: '<NULL>'
[ 3180.243432] kobject: 'map0' (00000000f663b250): kobject_uevent_env
[ 3180.243433] kobject: 'map0' (00000000f663b250): kobject_uevent_env:
filter function caused the event to drop!
[ 3180.243565] Configuring 0000000048576d33 device
[ 3180.243598] tcmu nl cmd 1/-2 completion could not find device with
dev id 91.
[ 3180.243606] tcmu nl cmd 1/-2 completion could not find device with
dev id 91.
[ 3180.243618] kobject: 'uio8' (00000000d48cde09): fill_kobj_path:
path = '/devices/tcm_user/uio/uio8'
[ 3180.243622] tcmu nl cmd 1/-2 completion could not find device with
dev id 91.
[ 3180.243640] kobject: 'maps' (00000000592a7aac):
kobject_add_internal: parent: 'uio8', set: '<NULL>'
[ 3180.243646] kobject: 'map0' (0000000009bdede6):
kobject_add_internal: parent: 'maps', set: '<NULL>'
[ 3180.243656] kobject: 'map0' (0000000009bdede6): kobject_uevent_env
[ 3180.243658] kobject: 'map0' (0000000009bdede6): kobject_uevent_env:
filter function caused the event to drop!
[ 3180.243726] se_dev->se_dev_ptr already set for storage object
[ 3180.243731] se_dev->se_dev_ptr already set for storage object
[ 3180.243735] se_dev->se_dev_ptr already set for storage object
[ 3180.243738] se_dev->se_dev_ptr already set for storage object
[ 3180.243742] se_dev->se_dev_ptr already set for storage object
[ 3180.243746] se_dev->se_dev_ptr already set for storage object
[ 3180.243749] se_dev->se_dev_ptr already set for storage object
[ 3180.243760] se_dev->se_dev_ptr already set for storage object
[ 3180.243763] se_dev->se_dev_ptr already set for storage object
[ 3180.243767] se_dev->se_dev_ptr already set for storage object
[ 3180.243777] se_dev->se_dev_ptr already set for storage object
[ 3180.243780] se_dev->se_dev_ptr already set for storage object
[ 3180.243784] se_dev->se_dev_ptr already set for storage object
[ 3180.243788] se_dev->se_dev_ptr already set for storage object
[ 3180.244302] kobject: 'uio10' (000000001e7fdf06):
kobject_add_internal: parent: 'uio', set: 'devices'
[ 3180.244472] tcmu nl cmd 1/-2 completion could not find device with
dev id 93.
[ 3180.244628] kobject: 'uio11' (00000000a5f1af78):
kobject_add_internal: parent: 'uio', set: 'devices'
[ 3180.244738] kobject: 'uio11' (00000000a5f1af78): kobject_uevent_env
[ 3180.244746] kobject: 'uio10' (000000001e7fdf06): kobject_uevent_env
[ 3180.244753] kobject: 'uio10' (000000001e7fdf06): fill_kobj_path:
path = '/devices/tcm_user/uio/uio10'
[ 3180.244781] kobject: 'maps' (00000000def336c9):
kobject_add_internal: parent: 'uio10', set: '<NULL>'
[ 3180.244787] kobject: 'map0' (0000000026045935):
kobject_add_internal: parent: 'maps', set: '<NULL>'
[ 3180.244797] kobject: 'map0' (0000000026045935): kobject_uevent_env
[ 3180.244798] kobject: 'map0' (0000000026045935): kobject_uevent_env:
filter function caused the event to drop!
[ 3180.244820] kobject: 'uio12' (00000000768952da):
kobject_add_internal: parent: 'uio', set: 'devices'
[ 3180.244837] list_add double add: new=ffff888017480000,
prev=ffffffff82e35ba0, next=ffff888017480000.
[ 3180.244855] tcmu nl cmd 1/-2 completion could not find device with
dev id 93.
[ 3180.244883] kobject: 'uio12' (00000000768952da): kobject_uevent_env
[ 3180.244888] kobject: 'uio12' (00000000768952da): fill_kobj_path:
path = '/devices/tcm_user/uio/uio12'
[ 3180.244894] ------------[ cut here ]------------
[ 3180.244897] kernel BUG at lib/list_debug.c:33!
[ 3180.244901] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 3180.244902] kobject: 'maps' (000000008b3ebaee):
kobject_add_internal: parent: 'uio12', set: '<NULL>'
[ 3180.244903] CPU: 5 PID: 240588 Comm: node Not tainted
6.4.0-rc2hocus-00247-g02bf964976ef-dirty #11
1a56ed25763fc52a0220ba3bab2f1b70cacabece
[ 3180.244905] kobject: 'map0' (0000000012d7aa89):
kobject_add_internal: parent: 'maps', set: '<NULL>'
[ 3180.244908] kobject: 'map0' (0000000012d7aa89): kobject_uevent_env
[ 3180.244909] kobject: 'map0' (0000000012d7aa89): kobject_uevent_env:
filter function caused the event to drop!
[ 3180.244906] RIP: 0010:__list_add_valid+0x94/0xa0
[ 3180.244917] Code: d1 48 89 c6 4c 89 c2 48 c7 c7 38 e1 4b 82 e8 63
25 b3 ff 0f 0b 48 89 f2 48 89 c1 48 89 fe 48 c7 c7 90 e1 4b 82 e8 4c
25 b3 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90
90 90
[ 3180.244918] RSP: 0018:ffffc90002e7fd68 EFLAGS: 00010246
[ 3180.244919] RAX: 0000000000000058 RBX: ffff888017480018 RCX:
0000000000000000
[ 3180.244919] RDX: 0000000000000000 RSI: ffffffff824440d9 RDI:
00000000ffffffff
[ 3180.244920] RBP: ffffc90002e7fd68 R08: 0000000000000001 R09:
0000000000000001
[ 3180.244921] R10: 000000001b629664 R11: 0000000000000005 R12:
0000000000000000
[ 3180.244921] R13: ffff888017480000 R14: ffff888017480000 R15:
ffff888017480010
[ 3180.244924] FS: 00007f26e5a526c0(0000) GS:ffff88841fc80000(0000)
knlGS:0000000000000000
[ 3180.244924] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3180.244925] CR2: 00007f0104208440 CR3: 000000032af22000 CR4:
00000000003506a0
[ 3180.244926] Call Trace:
[ 3180.244926] <TASK>
[ 3180.244927] tcmu_configure_device+0x29f/0x3a0
[ 3180.244933] target_configure_device+0x8c/0x2f0
[ 3180.244936] target_dev_enable_store+0x32/0x60
[ 3180.244940] configfs_write_iter+0xd5/0x140
[ 3180.244944] vfs_write+0x1ed/0x4f0
[ 3180.244948] ksys_write+0x70/0xf0
[ 3180.244949] __x64_sys_write+0x18/0x20
[ 3180.244950] do_syscall_64+0x3e/0x90
[ 3180.244956] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 3180.244962] RIP: 0033:0x7f26e875611f
[ 3180.244963] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 d5
f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00
00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 8c d5 f8
ff 48
[ 3180.244963] RSP: 002b:00007f26e5a51cf0 EFLAGS: 00000293 ORIG_RAX:
0000000000000001
[ 3180.244966] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
00007f26e875611f
[ 3180.244966] RDX: 0000000000000001 RSI: 00007f26be6549f0 RDI:
0000000000000030
[ 3180.244967] RBP: 00007f26e5a51e20 R08: 0000000000000000 R09:
00000000ffffffff
[ 3180.244967] R10: 0000000000000000 R11: 0000000000000293 R12:
00007f26e5a525c0
[ 3180.244968] R13: 00007f26e5cab8a8 R14: 0000000000000001 R15:
0000000000000400
[ 3180.244968] </TASK>
[ 3180.244969] ---[ end trace 0000000000000000 ]---
[ 3180.244970] RIP: 0010:__list_add_valid+0x94/0xa0
[ 3180.244971] Code: d1 48 89 c6 4c 89 c2 48 c7 c7 38 e1 4b 82 e8 63
25 b3 ff 0f 0b 48 89 f2 48 89 c1 48 89 fe 48 c7 c7 90 e1 4b 82 e8 4c
25 b3 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90
90 90
[ 3180.244972] RSP: 0018:ffffc90002e7fd68 EFLAGS: 00010246
[ 3180.244973] RAX: 0000000000000058 RBX: ffff888017480018 RCX:
0000000000000000
[ 3180.244973] RDX: 0000000000000000 RSI: ffffffff824440d9 RDI:
00000000ffffffff
[ 3180.244974] RBP: ffffc90002e7fd68 R08: 0000000000000001 R09:
0000000000000001
[ 3180.244974] R10: 000000001b629664 R11: 0000000000000005 R12:
0000000000000000
[ 3180.244975] R13: ffff888017480000 R14: ffff888017480000 R15:
ffff888017480010
[ 3180.244977] FS: 00007f26e5a526c0(0000) GS:ffff88841fc80000(0000)
knlGS:0000000000000000
[ 3180.244977] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3180.244978] CR2: 00007f0104208440 CR3: 000000032af22000 CR4:
00000000003506a0
[ 3180.245068] se_dev->se_dev_ptr already set for storage object
[ 3180.245087] kobject: 'uio11' (00000000a5f1af78): fill_kobj_path:
path = '/devices/tcm_user/uio/uio11'
[ 3180.245265] tcmu nl cmd 1/-2 completion could not find device with
dev id 91.
[ 3180.245491] kobject: 'maps' (000000009b2a87fb):
kobject_add_internal: parent: 'uio11', set: '<NULL>'
[ 3180.245749] tcmu nl cmd 1/-2 completion could not find device with
dev id 94.
[ 3180.245966] kobject: 'map0' (00000000d832f7b9):
kobject_add_internal: parent: 'maps', set: '<NULL>'
[ 3180.246150] tcmu nl cmd 1/-2 completion could not find device with
dev id 94.
[ 3180.246349] kobject: 'map0' (00000000d832f7b9): kobject_uevent_env
[ 3180.246523] tcmu nl cmd 1/-2 completion could not find device with
dev id 93.
[ 3180.246691] kobject: 'map0' (00000000d832f7b9): kobject_uevent_env:
filter function caused the event to drop!
[ 3180.246878] tcmu nl cmd 1/0 completion could not find device with
dev id 91.
[ 3180.263756] tcmu nl cmd 1/-2 completion could not find device with
dev id 93.
Best regards,
Grzegorz Uriasz
On 21/05/2023 13:28, Grzegorz Uriasz wrote:
Hi Dmitry,
Thank you for your feedback 😄
On 20/05/2023 10:46, Dmitry Bogdanov wrote:
Hi Grzegorz,
On Sat, May 20, 2023 at 02:26:14AM +0200, Grzegorz Uriasz wrote:
This fixes data corruptions arising from concurrent enabling of a
target
devices. When multiple enable calls are made concurrently then it is
possible for the target device to be set up twice which results in a
kernel BUG.
Introduces a per target device mutex for serializing enable requests.
Device enable call is already secured by configfs per-file mutex. That
is actually per device. So Enable procedures are already not executed
simulteniously.
True, I've checked the code in configfs and indeed there is a per
file/subsystem mutex.
Look like you wrongly identified the root cause of double list_add.
If you have an evidence that dev->dev_flags could have no DF_CONFIGURED
bit, then it meeans that it (dev_flags) is raced in other
configuration actions (udev_path, vpd_unit_serial, alias).
Bits in dev->dev_flags are written not atomically and if you writes to
enable, alias, udev_path,unit_serial files simulteniously, then some
bits could be lost.
IHMO the best solution is to make dev_flags changes be atomical.
I've tried that using the following patch:
---
drivers/target/target_core_configfs.c | 12 ++++++------
drivers/target/target_core_device.c | 2 +-
drivers/target/target_core_iblock.c | 2 +-
drivers/target/target_core_pscsi.c | 4 ++--
drivers/target/target_core_spc.c | 8 ++++----
drivers/target/target_core_tpg.c | 2 +-
include/target/target_core_backend.h | 2 +-
include/target/target_core_base.h | 4 ++--
8 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/drivers/target/target_core_configfs.c
b/drivers/target/target_core_configfs.c
index 74b67c346dfe..bdc06f654aa8 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1621,7 +1621,7 @@ static ssize_t
target_wwn_vpd_unit_serial_store(struct config_item *item,
* it is doing 'the right thing' wrt a world wide unique
* VPD Unit Serial Number that OS dependent multipath can depend
on.
*/
- if (dev->dev_flags & DF_FIRMWARE_VPD_UNIT_SERIAL) {
+ if (atomic_read(&dev->dev_flags) & DF_FIRMWARE_VPD_UNIT_SERIAL) {
pr_err("Underlying SCSI device firmware provided VPD"
" Unit Serial, ignoring request\n");
return -EOPNOTSUPP;
@@ -1654,7 +1654,7 @@ static ssize_t
target_wwn_vpd_unit_serial_store(struct config_item *item,
snprintf(buf, INQUIRY_VPD_SERIAL_LEN, "%s", page);
snprintf(dev->t10_wwn.unit_serial, INQUIRY_VPD_SERIAL_LEN,
"%s", strstrip(buf));
- dev->dev_flags |= DF_EMULATED_VPD_UNIT_SERIAL;
+ atomic_or(DF_EMULATED_VPD_UNIT_SERIAL, &dev->dev_flags);
pr_debug("Target_Core_ConfigFS: Set emulated VPD Unit Serial:"
" %s\n", dev->t10_wwn.unit_serial);
@@ -2263,7 +2263,7 @@ static ssize_t target_dev_alias_show(struct
config_item *item, char *page)
{
struct se_device *dev = to_device(item);
- if (!(dev->dev_flags & DF_USING_ALIAS))
+ if (!(atomic_read(&dev->dev_flags) & DF_USING_ALIAS))
return 0;
return snprintf(page, PAGE_SIZE, "%s\n", dev->dev_alias);
@@ -2289,7 +2289,7 @@ static ssize_t target_dev_alias_store(struct
config_item *item,
if (dev->dev_alias[read_bytes - 1] == '\n')
dev->dev_alias[read_bytes - 1] = '\0';
- dev->dev_flags |= DF_USING_ALIAS;
+ atomic_or(DF_USING_ALIAS, &dev->dev_flags);
pr_debug("Target_Core_ConfigFS: %s/%s set alias: %s\n",
config_item_name(&hba->hba_group.cg_item),
@@ -2303,7 +2303,7 @@ static ssize_t target_dev_udev_path_show(struct
config_item *item, char *page)
{
struct se_device *dev = to_device(item);
- if (!(dev->dev_flags & DF_USING_UDEV_PATH))
+ if (!(atomic_read(&dev->dev_flags) & DF_USING_UDEV_PATH))
return 0;
return snprintf(page, PAGE_SIZE, "%s\n", dev->udev_path);
@@ -2330,7 +2330,7 @@ static ssize_t
target_dev_udev_path_store(struct config_item *item,
if (dev->udev_path[read_bytes - 1] == '\n')
dev->udev_path[read_bytes - 1] = '\0';
- dev->dev_flags |= DF_USING_UDEV_PATH;
+ atomic_or(DF_USING_UDEV_PATH, &dev->dev_flags);
pr_debug("Target_Core_ConfigFS: %s/%s set udev_path: %s\n",
config_item_name(&hba->hba_group.cg_item),
diff --git a/drivers/target/target_core_device.c
b/drivers/target/target_core_device.c
index 90f3f4926172..5054b647dd0b 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -967,7 +967,7 @@ int target_configure_device(struct se_device *dev)
hba->dev_count++;
spin_unlock(&hba->device_lock);
- dev->dev_flags |= DF_CONFIGURED;
+ atomic_or(DF_CONFIGURED, &dev->dev_flags);
return 0;
diff --git a/drivers/target/target_core_iblock.c
b/drivers/target/target_core_iblock.c
index cc838ffd1294..38d0d104661d 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -112,7 +112,7 @@ static int iblock_configure_device(struct
se_device *dev)
if (!ib_dev->ibd_readonly)
mode |= FMODE_WRITE;
else
- dev->dev_flags |= DF_READ_ONLY;
+ atomic_or(DF_READ_ONLY, &dev->dev_flags);
bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
if (IS_ERR(bd)) {
diff --git a/drivers/target/target_core_pscsi.c
b/drivers/target/target_core_pscsi.c
index e7425549e39c..36a1ac519f0b 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -201,7 +201,7 @@ pscsi_get_inquiry_vpd_serial(struct scsi_device
*sdev, struct t10_wwn *wwn)
snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s",
&buf[4]);
- wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
+ atomic_or(DF_FIRMWARE_VPD_UNIT_SERIAL, &wwn->t10_dev->dev_flags);
kfree(buf);
return 0;
@@ -450,7 +450,7 @@ static int pscsi_configure_device(struct
se_device *dev)
* For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
* reference, we enforce that udev_path has been set
*/
- if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
+ if (!(atomic_read(&dev->dev_flags) & DF_USING_UDEV_PATH)) {
pr_err("pSCSI: udev_path attribute has not"
" been set before ENABLE=1\n");
return -EINVAL;
diff --git a/drivers/target/target_core_spc.c
b/drivers/target/target_core_spc.c
index 89c0d56294cc..d380d08a2df0 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -159,7 +159,7 @@ spc_emulate_evpd_80(struct se_cmd *cmd, unsigned
char *buf)
struct se_device *dev = cmd->se_dev;
u16 len;
- if (dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL) {
+ if (atomic_read(&dev->dev_flags) & DF_EMULATED_VPD_UNIT_SERIAL) {
len = sprintf(&buf[4], "%s", dev->t10_wwn.unit_serial);
len++; /* Extra Byte for NULL Terminator */
buf[3] = len;
@@ -239,7 +239,7 @@ spc_emulate_evpd_83(struct se_cmd *cmd, unsigned
char *buf)
* /sys/kernel/config/target/core/$HBA/$DEV/wwn/vpd_unit_serial
* value in order to return the NAA id.
*/
- if (!(dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL))
+ if (!(atomic_read(&dev->dev_flags) & DF_EMULATED_VPD_UNIT_SERIAL))
goto check_t10_vend_desc;
/* CODE SET == Binary */
@@ -267,7 +267,7 @@ spc_emulate_evpd_83(struct se_cmd *cmd, unsigned
char *buf)
*/
id_len = 8; /* For Vendor field */
- if (dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL)
+ if (atomic_read(&dev->dev_flags) & DF_EMULATED_VPD_UNIT_SERIAL)
id_len += sprintf(&buf[off+12], "%s:%s", prod,
&dev->t10_wwn.unit_serial[0]);
buf[off] = 0x2; /* ASCII */
@@ -720,7 +720,7 @@ spc_emulate_evpd_00(struct se_cmd *cmd, unsigned
char *buf)
* Registered Extended LUN WWN has been set via ConfigFS
* during device creation/restart.
*/
- if (cmd->se_dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL) {
+ if (atomic_read(&cmd->se_dev->dev_flags) &
DF_EMULATED_VPD_UNIT_SERIAL) {
buf[3] = ARRAY_SIZE(evpd_handlers);
for (p = 0; p < ARRAY_SIZE(evpd_handlers); ++p)
buf[p + 4] = evpd_handlers[p].page;
diff --git a/drivers/target/target_core_tpg.c
b/drivers/target/target_core_tpg.c
index c0e429e5ef31..c88dc36db6de 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -656,7 +656,7 @@ int core_tpg_add_lun(
list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
spin_unlock(&dev->se_port_lock);
- if (dev->dev_flags & DF_READ_ONLY)
+ if (atomic_read(&dev->dev_flags) & DF_READ_ONLY)
lun->lun_access_ro = true;
else
lun->lun_access_ro = lun_access_ro;
diff --git a/include/target/target_core_backend.h
b/include/target/target_core_backend.h
index a3c193df25b3..27c70a69e088 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -122,7 +122,7 @@ bool target_configure_unmap_from_queue(struct
se_dev_attrib *attrib,
static inline bool target_dev_configured(struct se_device *se_dev)
{
- return !!(se_dev->dev_flags & DF_CONFIGURED);
+ return !!(atomic_read(&se_dev->dev_flags) & DF_CONFIGURED);
}
#endif /* TARGET_CORE_BACKEND_H */
diff --git a/include/target/target_core_base.h
b/include/target/target_core_base.h
index 5f8e96f1516f..5794b2360c47 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -792,8 +792,8 @@ struct se_device_queue {
struct se_device {
/* Used for SAM Task Attribute ordering */
- u32 dev_cur_ordered_id;
- u32 dev_flags;
+ u32 dev_cur_ordered_id;
+ atomic_t dev_flags;
#define DF_CONFIGURED 0x00000001
#define DF_FIRMWARE_VPD_UNIT_SERIAL 0x00000002
#define DF_EMULATED_VPD_UNIT_SERIAL 0x00000004
