fb00cc2353
This warning was reported recently: WARNING: at drivers/scsi/libfc/fc_exch.c:478 fc_seq_send+0x14f/0x160 [libfc]() (Not tainted) Hardware name: ProLiant DL120 G7 Modules linked in: tcm_fc target_core_iblock target_core_file target_core_pscsi target_core_mod configfs dm_round_robin dm_multipath 8021q garp stp llc bnx2fc cnic uio fcoe libfcoe libfc scsi_transport_fc scsi_tgt autofs4 sunrpc pcc_cpufreq ipv6 hpilo hpwdt e1000e microcode iTCO_wdt iTCO_vendor_support serio_raw shpchp ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif pata_acpi ata_generic ata_piix hpsa dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 5464, comm: target_completi Not tainted 2.6.32-272.el6.x86_64 #1 Call Trace: [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0 [<ffffffff8106b79a>] ? warn_slowpath_null+0x1a/0x20 [<ffffffffa025f7df>] ? fc_seq_send+0x14f/0x160 [libfc] [<ffffffffa035cbce>] ? ft_queue_status+0x16e/0x210 [tcm_fc] [<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod] [<ffffffffa030a766>] ? target_complete_ok_work+0x106/0x4b0 [target_core_mod] [<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod] [<ffffffff8108c760>] ? worker_thread+0x170/0x2a0 [<ffffffff810920d0>] ? autoremove_wake_function+0x0/0x40 [<ffffffff8108c5f0>] ? worker_thread+0x0/0x2a0 [<ffffffff81091d66>] ? kthread+0x96/0xa0 [<ffffffff8100c14a>] ? child_rip+0xa/0x20 [<ffffffff81091cd0>] ? kthread+0x0/0xa0 [<ffffffff8100c140>] ? child_rip+0x0/0x20 It occurs because fc_seq_send can have multiple contexts executing within it at the same time, and fc_seq_send doesn't consistently use the ep->ex_lock that protects this structure. Because of that, its possible for one context to clear the INIT bit in the ep->esb_state field while another checks it, leading to the above stack trace generated by the WARN_ON in the function. We should probably undertake the effort to convert access to the fc_exch structures to use rcu, but that a larger work item. To just fix this specific issue, we can just extend the ex_lock protection through the entire fc_seq_send path Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Gris Ge <fge@redhat.com> CC: Robert Love <robert.w.love@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> |
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| .. | ||
| fc_disc.c | ||
| fc_elsct.c | ||
| fc_exch.c | ||
| fc_fcp.c | ||
| fc_frame.c | ||
| fc_libfc.c | ||
| fc_libfc.h | ||
| fc_lport.c | ||
| fc_npiv.c | ||
| fc_rport.c | ||
| Makefile | ||