Fix a bdi reregistration race, v3
PATCH 1/1 Fix a bdi reregistration race, v3
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
WARNING: CPU: 7 PID: 203 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x80() sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:32' Workqueue: events_unbound async_run_entry_fn Call Trace: [<ffffffff814ff5a4>] dump_stack+0x4c/0x65 [<ffffffff810746ba>] warn_slowpath_common+0x8a/0xc0 [<ffffffff81074736>] warn_slowpath_fmt+0x46/0x50 [<ffffffff81237ca8>] sysfs_warn_dup+0x68/0x80 [<ffffffff81237d8e>] sysfs_create_dir_ns+0x7e/0x90 [<ffffffff81291f58>] kobject_add_internal+0xa8/0x320 [<ffffffff812923a0>] kobject_add+0x60/0xb0 [<ffffffff8138c937>] device_add+0x107/0x5e0 [<ffffffff8138d018>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8138d05c>] device_create_vargs+0x1c/0x20 [<ffffffff8117f233>] bdi_register+0x63/0x2a0 [<ffffffff8117f497>] bdi_register_dev+0x27/0x30 [<ffffffff81281549>] add_disk+0x1a9/0x4e0 [<ffffffffa00c5739>] sd_probe_async+0x119/0x1d0 [sd_mod] [<ffffffff8109a81a>] async_run_entry_fn+0x4a/0x140 [<ffffffff81091078>] process_one_work+0x1d8/0x7c0 [<ffffffff81091774>] worker_thread+0x114/0x460 [<ffffffff81097878>] kthread+0xf8/0x110 [<ffffffff8150801f>] ret_from_fork+0x3f/0x70
Signed-off-by Bart Van Assche <[email protected]>
Cc Christoph Hellwig <[email protected]>
Cc Hannes Reinecke <[email protected]>
Cc <[email protected]>
--- drivers/scsi/scsi_sysfs.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-)
drivers/scsi/scsi_sysfs.c +29 -1
@@ -1272,9 +1272,26 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)return error; } +static int scsi_return_dev (struct device *dev,void *data) +{ +struct device **childp = data; + + *childp = dev; +return 0 ; +} + +/* Caller must call put_device() if this function does not return NULL. */ +static struct device *scsi_get_child_dev (struct device *dev) +{ +struct device *child =NULL ; + +device_for_each_child (dev, &child, scsi_return_dev); +return get_device (child); +} +void __scsi_remove_device (struct scsi_device *sdev) { -struct device *dev = &sdev->sdev_gendev; +struct device *dev = &sdev->sdev_gendev, *sdkp =NULL ;/* * This cleanup path is not reentrant and while it is impossible
@@ -1289,6 +1306,7 @@ void __scsi_remove_device(struct scsi_device *sdev)return ;bsg_unregister_queue (sdev->request_queue); + sdkp =scsi_get_child_dev (dev);device_unregister (&sdev->sdev_dev);transport_remove_device (dev);scsi_dh_remove_device (sdev);
@@ -1305,6 +1323,16 @@ void __scsi_remove_device(struct scsi_device *sdev)blk_cleanup_queue (sdev->request_queue);cancel_work_sync (&sdev->requeue_work); +/* +* blk_cleanup_queue() unregisters the BDI device. The name of the +* BDI device is derived from the dev_t of the /dev/sd<n> device. +* Keep a reference to the /dev/sd<n> device until the BDI device +* has been unregistered to avoid that a BDI device with the same +* name gets registered before blk_cleanup_queue() has finished. +*/ +if (sdkp) +put_device (sdkp); +if (sdev->host->hostt->slave_destroy) sdev->host->hostt->slave_destroy (sdev);transport_destroy_device (dev);
Signature · 1 line
2.7.3
Quoted 5 lines · Bart Van Assche
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
[ ... ]
(replying to my own e-mail)
If anyone could review this patch that would be very welcome.
Thanks,
Bart.
Quoted 10 lines · Bart Van Assche
Quoted 5 lines · Bart Van Assche
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
[ ... ]
(replying to my own e-mail)
If anyone could review this patch that would be very welcome.
Hi Bart,
I *think* I may be hitting this same problem running some tests here at Stratus -- I've got slub_debugging and other kernel debugging turned on while repeatedly hotplugging controllers at various timings during probe. It takes hours to hit, but I've seen it twice in the past week. I've got some other testing on my plate at the moment, but when I get a chance I can give your v3 a spin.
Here's an example (sorry for the wide width) ...
------------[ cut here ]------------ WARNING: CPU: 5 PID: 30702 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80 sysfs: cannot create duplicate filename '/devices/virtual/bdi/65:0' Modules linked in: btrfs xor raid6_pq msdos ext4 jbd2 mbcache matroxfb(OE) ccmod(POE) ftmod(OE) videosw(OE) ipmi_devintf fuse xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack bonding ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter vfat fat x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper lrw gf128mul ablk_helper cryptd dm_service_time pcspkr ses enclosure sg wmi nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c raid1 sr_mod cdrom crc32c_intel qla2xxx(OE) scsi_transport_fc ixgbe(OE) mdio igb(OE) ptp pps_core mpt3sas(OE) raid_class i2c_algo_bit sra_sense(OE) i2c_core sd_mod(OE) scsi_transport_sas dca scsi_hbas(OE) fjes ipmi_msghandler usb_storage dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ipmi_devintf] CPU: 5 PID: 30702 Comm: kworker/u97:7 Tainted: P W OE 4.6.0-rc6+ #37 Hardware name: Stratus ftServer 6800/G7LYY, BIOS BIOS Version 8.1:64 02/03/2016 Workqueue: events_unbound async_run_entry_fn 0000000000000286 00000000e136f6f8 ffff88038ae03a50 ffffffff8134359f ffff88038ae03aa0 0000000000000000 ffff88038ae03a90 ffffffff8108af31 0000001f5bdb0398 ffff880067e0e7e8 ffff88058f92def0 ffff88084bd2c008 Call Trace: [<ffffffff8134359f>] dump_stack+0x63/0x84 [<ffffffff8108af31>] __warn+0xd1/0xf0 [<ffffffff8108afaf>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff81297604>] sysfs_warn_dup+0x64/0x80 [<ffffffff812976ee>] sysfs_create_dir_ns+0x7e/0x90 [<ffffffff8134653a>] kobject_add_internal+0xaa/0x320 [<ffffffff8146bf93>] ? device_private_init+0x23/0x70 [<ffffffff813469e5>] kobject_add+0x75/0xd0 [<ffffffff816a9cd2>] ? mutex_lock+0x12/0x2f [<ffffffff8146c105>] device_add+0x125/0x610 [<ffffffff8146c7e8>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8146c82c>] device_create_vargs+0x1c/0x20 [<ffffffff811b209c>] bdi_register+0x8c/0x180 [<ffffffff811b21b7>] bdi_register_dev+0x27/0x30 [<ffffffff81327e7f>] add_disk+0x17f/0x4a0 [<ffffffff8147b955>] ? update_autosuspend+0x55/0x60 [<ffffffff8147ba14>] ? __pm_runtime_use_autosuspend+0x54/0x70 [<ffffffffa00a1a25>] sd_probe_async+0x115/0x1d0 [sd_mod] [<ffffffff810ad80a>] async_run_entry_fn+0x4a/0x140 [<ffffffff810a464e>] process_one_work+0x16e/0x420 [<ffffffff810a4f45>] worker_thread+0x125/0x4b0 [<ffffffff816a780d>] ? __schedule+0x2ad/0x8a0 [<ffffffff810a4e20>] ? rescuer_thread+0x380/0x380 [<ffffffff810aa9b8>] kthread+0xd8/0xf0 [<ffffffff816abb42>] ret_from_fork+0x22/0x40 [<ffffffff810aa8e0>] ? kthread_park+0x60/0x60 ---[ end trace 353add4e78cb2a75 ]--- ------------[ cut here ]------------ WARNING: CPU: 5 PID: 30702 at lib/kobject.c:240 kobject_add_internal+0x262/0x320 kobject_add_internal failed for 65:0 with -EEXIST, don't try to register things with the same name in the same directory. Modules linked in: btrfs xor raid6_pq msdos ext4 jbd2 mbcache matroxfb(OE) ccmod(POE) ftmod(OE) videosw(OE) ipmi_devintf fuse xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack bonding ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter vfat fat x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper lrw gf128mul ablk_helper cryptd dm_service_time pcspkr ses enclosure sg wmi nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c raid1 sr_mod cdrom crc32c_intel qla2xxx(OE) scsi_transport_fc ixgbe(OE) mdio igb(OE) ptp pps_core mpt3sas(OE) raid_class i2c_algo_bit sra_sense(OE) i2c_core sd_mod(OE) scsi_transport_sas dca scsi_hbas(OE) fjes ipmi_msghandler usb_storage dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ipmi_devintf] CPU: 5 PID: 30702 Comm: kworker/u97:7 Tainted: P W OE 4.6.0-rc6+ #37 Hardware name: Stratus ftServer 6800/G7LYY, BIOS BIOS Version 8.1:64 02/03/2016 Workqueue: events_unbound async_run_entry_fn 0000000000000286 00000000e136f6f8 ffff88038ae03aa0 ffffffff8134359f ffff88038ae03af0 0000000000000000 ffff88038ae03ae0 ffffffff8108af31 000000f08129760c ffff880853a4f4f8 ffff88003b529e68 00000000ffffffef Call Trace: [<ffffffff8134359f>] dump_stack+0x63/0x84 [<ffffffff8108af31>] __warn+0xd1/0xf0 [<ffffffff8108afaf>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff813466f2>] kobject_add_internal+0x262/0x320 [<ffffffff8146bf93>] ? device_private_init+0x23/0x70 [<ffffffff813469e5>] kobject_add+0x75/0xd0 [<ffffffff816a9cd2>] ? mutex_lock+0x12/0x2f [<ffffffff8146c105>] device_add+0x125/0x610 [<ffffffff8146c7e8>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8146c82c>] device_create_vargs+0x1c/0x20 [<ffffffff811b209c>] bdi_register+0x8c/0x180 [<ffffffff811b21b7>] bdi_register_dev+0x27/0x30 [<ffffffff81327e7f>] add_disk+0x17f/0x4a0 [<ffffffff8147b955>] ? update_autosuspend+0x55/0x60 [<ffffffff8147ba14>] ? __pm_runtime_use_autosuspend+0x54/0x70 [<ffffffffa00a1a25>] sd_probe_async+0x115/0x1d0 [sd_mod] [<ffffffff810ad80a>] async_run_entry_fn+0x4a/0x140 [<ffffffff810a464e>] process_one_work+0x16e/0x420 [<ffffffff810a4f45>] worker_thread+0x125/0x4b0 [<ffffffff816a780d>] ? __schedule+0x2ad/0x8a0 [<ffffffff810a4e20>] ? rescuer_thread+0x380/0x380 [<ffffffff810aa9b8>] kthread+0xd8/0xf0 [<ffffffff816abb42>] ret_from_fork+0x22/0x40 [<ffffffff810aa8e0>] ? kthread_park+0x60/0x60 ---[ end trace 353add4e78cb2a76 ]--- BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: [<ffffffff81297924>] sysfs_do_create_link_sd.isra.2+0x34/0xb0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: btrfs xor raid6_pq msdos ext4 jbd2 mbcache matroxfb(OE) ccmod(POE) ftmod(OE) videosw(OE) ipmi_devintf fuse xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack bonding ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter vfat fat x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper lrw gf128mul ablk_helper cryptd dm_service_time pcspkr ses enclosure sg wmi nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c raid1 sr_mod cdrom crc32c_intel qla2xxx(OE) scsi_transport_fc ixgbe(OE) mdio igb(OE) ptp pps_core mpt3sas(OE) raid_class i2c_algo_bit sra_sense(OE) i2c_core sd_mod(OE) scsi_transport_sas dca scsi_hbas(OE) fjes ipmi_msghandler usb_storage dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ipmi_devintf] CPU: 5 PID: 30702 Comm: kworker/u97:7 Tainted: P W OE 4.6.0-rc6+ #37 Hardware name: Stratus ftServer 6800/G7LYY, BIOS BIOS Version 8.1:64 02/03/2016 Workqueue: events_unbound async_run_entry_fn task: ffff88038adfda40 ti: ffff88038ae00000 task.ti: ffff88038ae00000 RIP: 0010:[<ffffffff81297924>] [<ffffffff81297924>] sysfs_do_create_link_sd.isra.2+0x34/0xb0 RSP: 0018:ffff88038ae03d08 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000040 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000040 RDI: ffffffff8221adf0 RBP: ffff88038ae03d30 R08: ffff88084d4b91f0 R09: 0000000000000000 R10: ffff8801f1832608 R11: ffff8801f1832f88 R12: ffffffff81a2034e R13: ffff8808580bae58 R14: 0000000000000001 R15: ffff8804ac9c7038 FS: 0000000000000000(0000) GS:ffff88085f940000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 0000001054486000 CR4: 00000000001406e0 Stack: ffff8804ac9c6fc8 ffff8804ac9c7048 ffff8808352a0a58 ffff8804ac9c6fd4 ffff8804ac9c7038 ffff88038ae03d40 ffffffff812979c5 ffff88038ae03da8 ffffffff81327f15 ffff8804ac9c6fc8 041000008ae03d68 ffff8804ac9c6fc8 Call Trace: [<ffffffff812979c5>] sysfs_create_link+0x25/0x40 [<ffffffff81327f15>] add_disk+0x215/0x4a0 [<ffffffffa00a1a25>] sd_probe_async+0x115/0x1d0 [sd_mod] [<ffffffff810ad80a>] async_run_entry_fn+0x4a/0x140 [<ffffffff810a464e>] process_one_work+0x16e/0x420 [<ffffffff810a4f45>] worker_thread+0x125/0x4b0 [<ffffffff816a780d>] ? __schedule+0x2ad/0x8a0 [<ffffffff810a4e20>] ? rescuer_thread+0x380/0x380 [<ffffffff810aa9b8>] kthread+0xd8/0xf0 [<ffffffff816abb42>] ret_from_fork+0x22/0x40 [<ffffffff810aa8e0>] ? kthread_park+0x60/0x60 Code: 48 89 e5 41 57 41 56 41 55 41 54 49 89 d4 53 74 73 48 85 ff 49 89 fd 74 6b 48 89 f3 48 c7 c7 f0 ad 21 82 41 89 ce e8 ac 3d 41 00 <48> 8b 1b 48 85 db 74 08 48 89 df e8 ac c1 ff ff 48 c7 c7 f0 ad RIP [<ffffffff81297924>] sysfs_do_create_link_sd.isra.2+0x34/0xb0 RSP <ffff88038ae03d08>
CR2: 0000000000000040
sd 1:0:0:2: [sds] Read Capacity(16) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK sd 1:0:0:2: [sds] Sense not available.
sd 1:0:0:2: [sds] Read Capacity(10) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK sd 1:0:0:2: [sds] Sense not available.
sd 1:0:0:2: [sds] Write Protect is off
sd 1:0:0:2: [sds] Mode Sense: 00 00 00 60
sd 1:0:0:2: [sds] Asking for cache data failed
sd 1:0:0:2: [sds] Assuming drive cache: write through
Regards,
-- Joe
Quoted 8 lines · Joe Lawrence
Quoted 7 lines · Bart Van Assche
Quoted 5 lines · Bart Van Assche
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
[ ... ]
Quoted 8 lines
Quoted 3 lines
(replying to my own e-mail)
If anyone could review this patch that would be very welcome.
Hi Bart,
I *think* I may be hitting this same problem running some tests here at Stratus ... snip...
Hi Bart,
Good news = With your v3 patch, I didn't see the "sysfs: cannot create duplicate filename '/devices/virtual/bdi/65:0'" warning during my weekend testing (573 surprise disk HBA removals).
Bad news = I still crashed in add_disk > sysfs_create_link > sysfs_do_create_link_sd on a NULL target_kobj->sd ... unfortunately I don't have kdump working, so all I have is a serial console output to work with for now.
Regards,
-- Joe
Quoted 16 lines · Joe Lawrence
Quoted 6 lines · Joe Lawrence
Quoted 5 lines · Bart Van Assche
Quoted 4 lines · Bart Van Assche
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
Quoted 8 lines
Quoted 5 lines
Quoted 1 line
[ ... ]
(replying to my own e-mail)
If anyone could review this patch that would be very welcome.
I *think* I may be hitting this same problem running some tests here at Stratus ... snip...
Quoted 8 lines
Good news = With your v3 patch, I didn't see the "sysfs: cannot create duplicate filename '/devices/virtual/bdi/65:0'" warning during my weekend testing (573 surprise disk HBA removals).
Bad news = I still crashed in
add_disk>sysfs_create_link>sysfs_do_create_link_sdon a NULLtarget_kobj->sd... unfortunately I don't have kdump working, so all I have is a serial console output to work with for now.
(replying to an e-mail of one month ago)
Hello Joe,
Earlier today I discovered a subtle bug in v3 of this patch. It would be appreciated if you could give v4 a try. The only substantial difference between v3 and v4 is that a "if (dev->class != &sdev_class)" test has been added.
Thanks,
Bart.
[PATCH] Fix a bdi reregistration race, v4
Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning gets triggered:
WARNING: CPU: 7 PID: 203 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x80() sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:32' Workqueue: events_unbound async_run_entry_fn Call Trace: [<ffffffff814ff5a4>] dump_stack+0x4c/0x65 [<ffffffff810746ba>] warn_slowpath_common+0x8a/0xc0 [<ffffffff81074736>] warn_slowpath_fmt+0x46/0x50 [<ffffffff81237ca8>] sysfs_warn_dup+0x68/0x80 [<ffffffff81237d8e>] sysfs_create_dir_ns+0x7e/0x90 [<ffffffff81291f58>] kobject_add_internal+0xa8/0x320 [<ffffffff812923a0>] kobject_add+0x60/0xb0 [<ffffffff8138c937>] device_add+0x107/0x5e0 [<ffffffff8138d018>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8138d05c>] device_create_vargs+0x1c/0x20 [<ffffffff8117f233>] bdi_register+0x63/0x2a0 [<ffffffff8117f497>] bdi_register_dev+0x27/0x30 [<ffffffff81281549>] add_disk+0x1a9/0x4e0 [<ffffffffa00c5739>] sd_probe_async+0x119/0x1d0 [sd_mod] [<ffffffff8109a81a>] async_run_entry_fn+0x4a/0x140 [<ffffffff81091078>] process_one_work+0x1d8/0x7c0 [<ffffffff81091774>] worker_thread+0x114/0x460 [<ffffffff81097878>] kthread+0xf8/0x110 [<ffffffff8150801f>] ret_from_fork+0x3f/0x70
Signed-off-by Bart Van Assche <[email protected]>
Cc Christoph Hellwig <[email protected]>
Cc Hannes Reinecke <[email protected]>
Cc <[email protected]>
--- drivers/scsi/scsi_sysfs.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-)
drivers/scsi/scsi_sysfs.c +38 -1
@@ -1273,9 +1273,35 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)return error; } +/** +* scsi_filter_sd - Look up the device structure embedded in a disk structure +* @dev: A sdev_gendev device +* @data: A struct device pointer +* +* sdev_gendev devices have two children - the sdev_dev device and for SCSI +* disks, the device embedded in a scsi_disk. +*/ +static int scsi_filter_sd (struct device *dev,void *data) +{ +struct device **childp = data; + +if (dev->class != &sdev_class) + *childp = dev; +return 0 ; +} + +/* Caller must call put_device() if this function does not return NULL. */ +static struct device *scsi_get_sd (struct device *dev) +{ +struct device *child =NULL ; + +device_for_each_child (dev, &child, scsi_filter_sd); +return get_device (child); +} +void __scsi_remove_device (struct scsi_device *sdev) { -struct device *dev = &sdev->sdev_gendev; +struct device *dev = &sdev->sdev_gendev, *sdp =NULL ;/* * This cleanup path is not reentrant and while it is impossible
@@ -1290,6 +1316,7 @@ void __scsi_remove_device(struct scsi_device *sdev)return ;bsg_unregister_queue (sdev->request_queue); + sdp =scsi_get_sd (dev);device_unregister (&sdev->sdev_dev);transport_remove_device (dev);scsi_dh_remove_device (sdev);
@@ -1306,6 +1333,16 @@ void __scsi_remove_device(struct scsi_device *sdev)blk_cleanup_queue (sdev->request_queue);cancel_work_sync (&sdev->requeue_work); +/* +* blk_cleanup_queue() unregisters the BDI device. The name of the +* BDI device is derived from the dev_t of the /dev/sd<n> device. +* Keep a reference to the /dev/sd<n> device until the BDI device +* has been unregistered to avoid that a BDI device with the same +* name gets registered before blk_cleanup_queue() has finished. +*/ +if (sdp) +put_device (sdp); +if (sdev->host->hostt->slave_destroy) sdev->host->hostt->slave_destroy (sdev);transport_destroy_device (dev);
Signature · 1 line
2.8.3
Quoted 4 lines · Bart Van Assche
Earlier today I discovered a subtle bug in v3 of this patch. It would be appreciated if you could give v4 a try. The only substantial difference between v3 and v4 is that a "if (
dev->class!=&sdev_class)" test has been added.
(again replying to my own e-mail)
Sorry but even v4 was not perfect. Will post v5 later today.
Bart.