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authorChristoph Hellwig <hch@lst.de>2015-04-23 09:48:49 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-13 05:15:42 -0700
commit7332f3217887bf622efd06ef39e59dbae60d63e3 (patch)
tree9fdee091a02d977133c71d7dcf44529da889da3d
parentea5f56ae530677ac4a671c6aff9f0c270b1b12ad (diff)
3w-sas: fix command completion race
commit 579d69bc1fd56d5af5761969aa529d1d1c188300 upstream. The 3w-sas driver needs to tear down the dma mappings before returning the command to the midlayer, as there is no guarantee the sglist and count are valid after that point. Also remove the dma mapping helpers which have another inherent race due to the request_id index. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Torsten Luettgert <ml-lkml@enda.eu> Tested-by: Bernd Kardatzki <Bernd.Kardatzki@med.uni-tuebingen.de> Acked-by: Adam Radford <aradford@gmail.com> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/scsi/3w-sas.c50
-rw-r--r--drivers/scsi/3w-sas.h4
2 files changed, 10 insertions, 44 deletions
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 4de346017e9f..61702ac00d42 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -303,26 +303,6 @@ static int twl_post_command_packet(TW_Device_Extension *tw_dev, int request_id)
return 0;
} /* End twl_post_command_packet() */
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twl_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
- int use_sg;
- struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
- use_sg = scsi_dma_map(cmd);
- if (!use_sg)
- return 0;
- else if (use_sg < 0) {
- TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1, "Failed to map scatter gather list");
- return 0;
- }
-
- cmd->SCp.phase = TW_PHASE_SGLIST;
- cmd->SCp.have_data_in = use_sg;
-
- return use_sg;
-} /* End twl_map_scsi_sg_data() */
-
/* This function hands scsi cdb's to the firmware */
static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry_ISO *sglistarg)
{
@@ -370,8 +350,8 @@ static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
if (!sglistarg) {
/* Map sglist from scsi layer to cmd packet */
if (scsi_sg_count(srb)) {
- sg_count = twl_map_scsi_sg_data(tw_dev, request_id);
- if (sg_count == 0)
+ sg_count = scsi_dma_map(srb);
+ if (sg_count <= 0)
goto out;
scsi_for_each_sg(srb, sg, sg_count, i) {
@@ -1116,15 +1096,6 @@ out:
return retval;
} /* End twl_initialize_device_extension() */
-/* This function will perform a pci-dma unmap */
-static void twl_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
- struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
- if (cmd->SCp.phase == TW_PHASE_SGLIST)
- scsi_dma_unmap(cmd);
-} /* End twl_unmap_scsi_data() */
-
/* This function will handle attention interrupts */
static int twl_handle_attention_interrupt(TW_Device_Extension *tw_dev)
{
@@ -1265,11 +1236,11 @@ static irqreturn_t twl_interrupt(int irq, void *dev_instance)
}
/* Now complete the io */
+ scsi_dma_unmap(cmd);
+ cmd->scsi_done(cmd);
tw_dev->state[request_id] = TW_S_COMPLETED;
twl_free_request_id(tw_dev, request_id);
tw_dev->posted_request_count--;
- tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
- twl_unmap_scsi_data(tw_dev, request_id);
}
/* Check for another response interrupt */
@@ -1414,10 +1385,12 @@ static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_res
if ((tw_dev->state[i] != TW_S_FINISHED) &&
(tw_dev->state[i] != TW_S_INITIAL) &&
(tw_dev->state[i] != TW_S_COMPLETED)) {
- if (tw_dev->srb[i]) {
- tw_dev->srb[i]->result = (DID_RESET << 16);
- tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
- twl_unmap_scsi_data(tw_dev, i);
+ struct scsi_cmnd *cmd = tw_dev->srb[i];
+
+ if (cmd) {
+ cmd->result = (DID_RESET << 16);
+ scsi_dma_unmap(cmd);
+ cmd->scsi_done(cmd);
}
}
}
@@ -1521,9 +1494,6 @@ static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
/* Save the scsi command for use by the ISR */
tw_dev->srb[request_id] = SCpnt;
- /* Initialize phase to zero */
- SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
retval = twl_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
if (retval) {
tw_dev->state[request_id] = TW_S_COMPLETED;
diff --git a/drivers/scsi/3w-sas.h b/drivers/scsi/3w-sas.h
index d474892701d4..fec6449c7595 100644
--- a/drivers/scsi/3w-sas.h
+++ b/drivers/scsi/3w-sas.h
@@ -103,10 +103,6 @@ static char *twl_aen_severity_table[] =
#define TW_CURRENT_DRIVER_BUILD 0
#define TW_CURRENT_DRIVER_BRANCH 0
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SGLIST 2
-
/* Misc defines */
#define TW_SECTOR_SIZE 512
#define TW_MAX_UNITS 32