From 3b493f9f06d19056669fe94b0933aaea06f3fee6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 11 Jan 2016 21:31:09 -0800 Subject: target: Fix LUN_RESET active I/O handling for ACK_KREF commit febe562c20dfa8f33bee7d419c6b517986a5aa33 upstream. This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active se_cmd I/O, that can be triggered during se_cmd descriptor shutdown + release via core_tmr_drain_state_list() code. To address this bug, add common __target_check_io_state() helper for ABORT_TASK + LUN_RESET w/ CMD_T_COMPLETE checking, and set CMD_T_ABORTED + obtain ->cmd_kref for both cases ahead of last target_put_sess_cmd() after TFO->aborted_task() -> transport_cmd_finish_abort() callback has completed. It also introduces SCF_ACK_KREF to determine when transport_cmd_finish_abort() needs to drop the second extra reference, ahead of calling target_put_sess_cmd() for the final kref_put(&se_cmd->cmd_kref). It also updates transport_cmd_check_stop() to avoid holding se_cmd->t_state_lock while dropping se_cmd device state via target_remove_from_state_list(), now that core_tmr_drain_state_list() is holding the se_device lock while checking se_cmd state from within TMR logic. Finally, move transport_put_cmd() release of SGL + TMR + extended CDB memory into target_free_cmd_mem() in order to avoid potential resource leaks in TMR ABORT_TASK + LUN_RESET code-paths. Also update target_release_cmd_kref() accordingly. Reviewed-by: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- include/target/target_core_base.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/target') diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index aabf0aca0171..02a4d02d881d 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -138,6 +138,7 @@ enum se_cmd_flags_table { SCF_COMPARE_AND_WRITE = 0x00080000, SCF_COMPARE_AND_WRITE_POST = 0x00100000, SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC = 0x00200000, + SCF_ACK_KREF = 0x00400000, }; /* struct se_dev_entry->lun_flags and struct se_lun->lun_access */ -- cgit v1.2.3