This patch causes a regression when using the iscsi initiator over TCP for me. When mounting a newly created ext4 filesystem I get the following BUG: [ 31.611803] BUG: unable to handle kernel NULL pointer dereference at 000000000000000c [ 31.613563] IP: [<ffffffff8197b38d>] iscsi_tcp_segment_done+0x2bd/0x380 [ 31.613563] PGD 7a3e4067 PUD 7a45f067 PMD 0 [ 31.613563] Oops: 0000 [#1] SMP [ 31.613563] Modules linked in: [ 31.613563] CPU: 3 PID: 3739 Comm: kworker/u8:5 Not tainted 3.16.0-rc2 #187 [ 31.613563] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 31.613563] Workqueue: iscsi_q_2 iscsi_xmitworker [ 31.613563] task: ffff88007b33cf10 ti: ffff88007ad94000 task.ti: ffff88007ad94000 [ 31.613563] RIP: 0010:[<ffffffff8197b38d>] [<ffffffff8197b38d>] iscsi_tcp_segment_done+0x2bd/0x380 [ 31.613563] RSP: 0018:ffff88007ad97b38 EFLAGS: 00010246 [ 31.613563] RAX: 0000000000000000 RBX: ffff88007cd67910 RCX: 0000000000000200 [ 31.613563] RDX: 0000000000002000 RSI: 0000000000000000 RDI: ffff88007cd67910 [ 31.613563] RBP: ffff88007ad97b98 R08: 0000000000000200 R09: 0000000000000000 [ 31.613563] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 31.613563] R13: ffff88007cd67780 R14: 0000000000000000 R15: 0000000000000000 [ 31.613563] FS: 0000000000000000(0000) GS:ffff88007fd80000(0000) knlGS:0000000000000000 [ 31.613563] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 31.613563] CR2: 000000000000000c CR3: 000000007afd9000 CR4: 00000000000006e0 [ 31.613563] Stack: [ 31.613563] ffff88007ad97b98 ffffffff81c68fd6 ffffffff81c68f20 ffff88007c8e37c8 [ 31.613563] 000000007b33d728 ffff88007dc805b0 ffff88007ad97c58 0000000000000200 [ 31.613563] ffff88007cd67780 ffff880000c00040 ffff88007ad97c00 ffff88007cd67910 [ 31.613563] Call Trace: [ 31.613563] [<ffffffff81c68fd6>] ? inet_sendpage+0xb6/0x130 [ 31.613563] [<ffffffff81c68f20>] ? inet_dgram_connect+0x80/0x80 [ 31.613563] [<ffffffff8197bd95>] iscsi_sw_tcp_pdu_xmit+0xe5/0x2e0 [ 31.613563] [<ffffffff8197badf>] ? iscsi_sw_tcp_pdu_init+0x1bf/0x390 [ 31.613563] [<ffffffff81979b82>] iscsi_tcp_task_xmit+0xa2/0x2b0 [ 31.613563] [<ffffffff81974815>] ? iscsi_xmit_task+0x45/0xd0 [ 31.613563] [<ffffffff810fbb8d>] ? trace_hardirqs_on+0xd/0x10 [ 31.613563] [<ffffffff810b54a0>] ? __local_bh_enable_ip+0x70/0xd0 [ 31.613563] [<ffffffff81974829>] iscsi_xmit_task+0x59/0xd0 [ 31.613563] [<ffffffff81978468>] iscsi_xmitworker+0x288/0x330 [ 31.613563] [<ffffffff810cc847>] process_one_work+0x1c7/0x490 [ 31.613563] [<ffffffff810cc7dd>] ? process_one_work+0x15d/0x490 [ 31.613563] [<ffffffff810cd539>] worker_thread+0x119/0x4f0 [ 31.613563] [<ffffffff810fbb8d>] ? trace_hardirqs_on+0xd/0x10 [ 31.613563] [<ffffffff810cd420>] ? init_pwq+0x190/0x190 [ 31.613563] [<ffffffff810d3c3f>] kthread+0xdf/0x100 [ 31.613563] [<ffffffff810d3b60>] ? __init_kthread_worker+0x70/0x70 [ 31.613563] [<ffffffff81d904bc>] ret_from_fork+0x7c/0xb0 [ 31.613563] [<ffffffff810d3b60>] ? __init_kthread_worker+0x70/0x70 [ 31.613563] Code: 89 03 31 c0 e9 cc fe ff ff 0f 1f 44 00 00 48 8b 7b 30 e8 17 74 de ff 8b 53 10 c7 43 40 00 00 00 00 48 89 43 30 44 89 f6 48 89 df <8b> 40 0c 48 c7 03 00 00 00 00 2b 53 14 39 c2 0f 47 d0 89 53 08 (gdb) l *(iscsi_tcp_segment_done+0x2bd) 0xffffffff8197b38d is in iscsi_tcp_segment_done (../drivers/scsi/libiscsi_tcp.c:102). 97 iscsi_tcp_segment_init_sg(struct iscsi_segment *segment, 98 struct scatterlist *sg, unsigned int offset) 99 { 100 segment->sg = sg; 101 segment->sg_offset = offset; 102 segment->size = min(sg->length - offset, 103 segment->total_size - segment->total_copied); 104 segment->data = NULL; 105 } 106 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html