The failure to map user-space pages leads to scsi command leak. It can
happens mostly because of user-space daemon bugs (or OOM). This patch
makes tgt just notify a LLD of the failure with sense when
blk_rq_map_user() fails.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/scsi_tgt_lib.c | 23 ++++++++++++++++++++---
1 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index dc8781a..c05dff9 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -459,6 +459,16 @@ static struct request *tgt_cmd_hash_look
return rq;
}
+static void scsi_tgt_build_sense(unsigned char *sense_buffer, unsigned char key,
+ unsigned char asc, unsigned char asq)
+{
+ sense_buffer[0] = 0x70;
+ sense_buffer[2] = key;
+ sense_buffer[7] = 0xa;
+ sense_buffer[12] = asc;
+ sense_buffer[13] = asq;
+}
+
int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,
unsigned long uaddr, u32 len, unsigned long sense_uaddr,
u32 sense_len, u8 rw)
@@ -514,9 +524,16 @@ int scsi_tgt_kspace_exec(int host_no, in
if (len) {
err = scsi_map_user_pages(rq->end_io_data, cmd, uaddr, len, rw);
if (err) {
- eprintk("%p %d\n", cmd, err);
- err = -EAGAIN;
- goto done;
+ /*
+ * user-space daemon bugs or OOM
+ * TODO: we can do better for OOM.
+ */
+ eprintk("cmd %p ret %d uaddr %lx len %d rw %d\n",
+ cmd, err, uaddr, len, rw);
+ cmd->result = SAM_STAT_CHECK_CONDITION;
+ memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+ scsi_tgt_build_sense(cmd->sense_buffer,
+ HARDWARE_ERROR, 0, 0);
}
}
err = scsi_tgt_transfer_response(cmd);
--
1.4.3.2
-
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