** Description changed: [Impact] When a SATA device, attached to a SAS controller, begins generating errors (e.g. device failing, or someone yanked it), the SAS error handling will complete, but may leave zombie ATA commands that never get properly processed/freed. This can cause some ugly messages on the console, and eventually leads to a system hang-up. - WARNING: CPU: 0 PID: 28512 at drivers/ata/libata-eh.c:4037 - ata_eh_finish+0xb4/0xcc - CPU: 0 PID: 28512 Comm: kworker/u32:2 Tainted: G W OE 4.14.0#1 - ...... - Call trace: - [<ffff0000088b7bd0>] ata_eh_finish+0xb4/0xcc - [<ffff0000088b8420>] ata_do_eh+0xc4/0xd8 - [<ffff0000088b8478>] ata_std_error_handler+0x44/0x8c - [<ffff0000088b8068>] ata_scsi_port_error_handler+0x480/0x694 - [<ffff000008875fc4>] async_sas_ata_eh+0x4c/0x80 - [<ffff0000080f6be8>] async_run_entry_fn+0x4c/0x170 - [<ffff0000080ebd70>] process_one_work+0x144/0x390 - [<ffff0000080ec100>] worker_thread+0x144/0x418 - [<ffff0000080f2c98>] kthread+0x10c/0x138 - [<ffff0000080855dc>] ret_from_fork+0x10/0x18 + WARNING: CPU: 0 PID: 28512 at drivers/ata/libata-eh.c:4037 + ata_eh_finish+0xb4/0xcc + CPU: 0 PID: 28512 Comm: kworker/u32:2 Tainted: G W OE 4.14.0#1 + ...... + Call trace: + [<ffff0000088b7bd0>] ata_eh_finish+0xb4/0xcc + [<ffff0000088b8420>] ata_do_eh+0xc4/0xd8 + [<ffff0000088b8478>] ata_std_error_handler+0x44/0x8c + [<ffff0000088b8068>] ata_scsi_port_error_handler+0x480/0x694 + [<ffff000008875fc4>] async_sas_ata_eh+0x4c/0x80 + [<ffff0000080f6be8>] async_run_entry_fn+0x4c/0x170 + [<ffff0000080ebd70>] process_one_work+0x144/0x390 + [<ffff0000080ec100>] worker_thread+0x144/0x418 + [<ffff0000080f2c98>] kthread+0x10c/0x138 + [<ffff0000080855dc>] ret_from_fork+0x10/0x18 [Test Case] I don't have a reliable reproducer for this, but one possible test is to yank an active/hotpluggable SATA disk from its controller and see if the above symptoms occur. + [Fix] + The solution here is to call into libata to have it process the remaining commands, allowing us to free up the zombie commands, preventing the leak and eventual starvation. + [Regression Risk] This is a clean cherry-pick from upstream, so any regressions should have upstream support. As of this writing, there are no changesets in linux-next marked as Fixing this commit, implying that upstream has not yet found/fixed any bugs related to it.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1768971 Title: Warnings/hang during error handling of SATA disks on SAS controller Status in linux package in Ubuntu: In Progress Status in linux source package in Bionic: In Progress Bug description: [Impact] When a SATA device, attached to a SAS controller, begins generating errors (e.g. device failing, or someone yanked it), the SAS error handling will complete, but may leave zombie ATA commands that never get properly processed/freed. This can cause some ugly messages on the console, and eventually leads to a system hang-up. WARNING: CPU: 0 PID: 28512 at drivers/ata/libata-eh.c:4037 ata_eh_finish+0xb4/0xcc CPU: 0 PID: 28512 Comm: kworker/u32:2 Tainted: G W OE 4.14.0#1 ...... Call trace: [<ffff0000088b7bd0>] ata_eh_finish+0xb4/0xcc [<ffff0000088b8420>] ata_do_eh+0xc4/0xd8 [<ffff0000088b8478>] ata_std_error_handler+0x44/0x8c [<ffff0000088b8068>] ata_scsi_port_error_handler+0x480/0x694 [<ffff000008875fc4>] async_sas_ata_eh+0x4c/0x80 [<ffff0000080f6be8>] async_run_entry_fn+0x4c/0x170 [<ffff0000080ebd70>] process_one_work+0x144/0x390 [<ffff0000080ec100>] worker_thread+0x144/0x418 [<ffff0000080f2c98>] kthread+0x10c/0x138 [<ffff0000080855dc>] ret_from_fork+0x10/0x18 [Test Case] I don't have a reliable reproducer for this, but one possible test is to yank an active/hotpluggable SATA disk from its controller and see if the above symptoms occur. [Fix] The solution here is to call into libata to have it process the remaining commands, allowing us to free up the zombie commands, preventing the leak and eventual starvation. [Regression Risk] This is a clean cherry-pick from upstream, so any regressions should have upstream support. As of this writing, there are no changesets in linux-next marked as Fixing this commit, implying that upstream has not yet found/fixed any bugs related to it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768971/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
