target/file: walk properly over sg list
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Mon, 28 Nov 2011 11:33:10 +0000 (12:33 +0100)
committerNicholas Bellinger <nab@linux-iscsi.org>
Tue, 6 Dec 2011 06:00:57 +0000 (06:00 +0000)
commit9649fa1b8764f64c8cc4293e197e14cd46fe7205
treec22257cf450c45ae663db66604ee09e230939e4d
parent5c73b678f729ea087ef57b59a5d7b5dd3a97042b
target/file: walk properly over sg list

This patch changes fileio to use for_each_sg() when walking se_task->task_sg
memory passed into from loopback LLD struct scsi_cmnd scatterlist memory.

This addresses an issue where FILEIO backends with loopback where hitting the
following OOPs with mkfs.ext2:

|kernel BUG at include/linux/scatterlist.h:97!
|invalid opcode: 0000 [#1] PREEMPT SMP
|Modules linked in: sd_mod tcm_loop target_core_stgt scsi_tgt target_core_pscsi target_core_file target_core_iblock target_core_mod configfs scsi_mod
|
|Pid: 671, comm: LIO_fileio Not tainted 3.1.0-rc10+ #139 Bochs Bochs
|EIP: 0060:[<e0afd746>] EFLAGS: 00010202 CPU: 0
|EIP is at fd_do_task+0x396/0x420 [target_core_file]
| [<e0aa7884>] __transport_execute_tasks+0xd4/0x190 [target_core_mod]
| [<e0aa797c>] transport_execute_tasks+0x3c/0xf0 [target_core_mod]
|EIP: [<e0afd746>] fd_do_task+0x396/0x420 [target_core_file] SS:ESP 0068:dea47e90

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
drivers/target/target_core_file.c