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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-05-19 20:19:09 -0700 |
|---|---|---|
| committer | James Bottomley <jbottomley@parallels.com> | 2011-05-24 12:56:58 -0400 |
| commit | 97868c8905a1537153d406c4a3aa39a503a5c299 (patch) | |
| tree | 3814892385b463a3ba14d81bf4101285855300f6 /drivers/target | |
| parent | 3eef6257de48ff84a5d98ca533685df8a3beaeb8 (diff) | |
| download | linux-97868c8905a1537153d406c4a3aa39a503a5c299.tar.bz2 | |
[SCSI] target: Fix multi task->task_sg[] chaining logic bug
This patch fixes a bug in transport_do_task_sg_chain() used by HW target
mode modules with sg_chain() to provide a single sg_next() walkable memory
layout for use with pci_map_sg() and friends. This patch addresses an
issue with mapping multiple small block max_sector tasks across multiple
struct se_task->task_sg[] mappings for HW target mode operation.
This was causing OOPs with (cmd->t_task->t_tasks_no > 1) I/O traffic for
HW target drivers using transport_do_task_sg_chain(), and has been tested
so far with tcm_fc(openfcoe), tcm_qla2xxx, and ib_srpt fabrics with
t_tasks_no > 1 IBLOCK backends using a smaller max_sectors to trigger the
original issue.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: Kiran Patil <kiran.patil@intel.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_transport.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index b9d3501bdd91..833060e0de5e 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -4776,18 +4776,20 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) sg_end_cur->page_link &= ~0x02; sg_chain(sg_head, task_sg_num, sg_head_cur); - sg_count += (task->task_sg_num + 1); - } else sg_count += task->task_sg_num; + task_sg_num = (task->task_sg_num + 1); + } else { + sg_chain(sg_head, task_sg_num, sg_head_cur); + sg_count += task->task_sg_num; + task_sg_num = task->task_sg_num; + } sg_head = sg_head_cur; sg_link = sg_link_cur; - task_sg_num = task->task_sg_num; continue; } sg_head = sg_first = &task->task_sg[0]; sg_link = &task->task_sg[task->task_sg_num]; - task_sg_num = task->task_sg_num; /* * Check for single task.. */ @@ -4798,9 +4800,12 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) */ sg_end = &task->task_sg[task->task_sg_num - 1]; sg_end->page_link &= ~0x02; - sg_count += (task->task_sg_num + 1); - } else sg_count += task->task_sg_num; + task_sg_num = (task->task_sg_num + 1); + } else { + sg_count += task->task_sg_num; + task_sg_num = task->task_sg_num; + } } /* * Setup the starting pointer and total t_tasks_sg_linked_no including @@ -4809,21 +4814,20 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) T_TASK(cmd)->t_tasks_sg_chained = sg_first; T_TASK(cmd)->t_tasks_sg_chained_no = sg_count; - DEBUG_CMD_M("Setup T_TASK(cmd)->t_tasks_sg_chained: %p and" - " t_tasks_sg_chained_no: %u\n", T_TASK(cmd)->t_tasks_sg_chained, + DEBUG_CMD_M("Setup cmd: %p T_TASK(cmd)->t_tasks_sg_chained: %p and" + " t_tasks_sg_chained_no: %u\n", cmd, T_TASK(cmd)->t_tasks_sg_chained, T_TASK(cmd)->t_tasks_sg_chained_no); for_each_sg(T_TASK(cmd)->t_tasks_sg_chained, sg, T_TASK(cmd)->t_tasks_sg_chained_no, i) { - DEBUG_CMD_M("SG: %p page: %p length: %d offset: %d\n", - sg, sg_page(sg), sg->length, sg->offset); + DEBUG_CMD_M("SG[%d]: %p page: %p length: %d offset: %d, magic: 0x%08x\n", + i, sg, sg_page(sg), sg->length, sg->offset, sg->sg_magic); if (sg_is_chain(sg)) DEBUG_CMD_M("SG: %p sg_is_chain=1\n", sg); if (sg_is_last(sg)) DEBUG_CMD_M("SG: %p sg_is_last=1\n", sg); } - } EXPORT_SYMBOL(transport_do_task_sg_chain); |