Jan Beulich
2012-Feb-14 11:32 UTC
[PATCH] linux-2.6.18/blkfront: properly fail packet requests
c/s 1036:f5635e334aa5 ("blkfront: forward unknown IOCTLs to
scsi_cmd_ioctl() for /dev/sdX") uncovered a problem in blkfront''s
request handling: blk_pc_request()-s, among other sources resulting
from the handling of the SG_IO ioctl in scsi_cmd_ioctl(), must not be
passed to end_request() without prior adjustment: Neither is their
->hard_cur_sectors necessarily correct (potentially resulting in an
infinite loop), nor is ->errors ever getting set properly to reflect
the failure (sg_io() intentionally ignores the return value from
blk_execute_rq()).
As blktap2''s internally created devices have the same deficiency, fix
this there too.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/drivers/xen/blkfront/blkfront.c
+++ b/drivers/xen/blkfront/blkfront.c
@@ -709,6 +709,12 @@ void do_blkif_request(request_queue_t *r
while ((req = elv_next_request(rq)) != NULL) {
info = req->rq_disk->private_data;
if (!blk_fs_request(req)) {
+ if (blk_pc_request(req)) {
+ req->errors = (DID_ERROR << 16)
+ | (DRIVER_INVALID << 24);
+ req->hard_cur_sectors = (req->data_len
+ + 511) >> 9;
+ }
end_request(req, 0);
continue;
}
--- a/drivers/xen/blktap2/device.c
+++ b/drivers/xen/blktap2/device.c
@@ -3,6 +3,7 @@
#include <linux/cdrom.h>
#include <linux/hdreg.h>
#include <linux/module.h>
+#include <scsi/scsi.h>
#include <asm/tlbflush.h>
#include <scsi/scsi.h>
@@ -825,6 +826,12 @@ blktap_device_run_queue(struct blktap *t
while ((req = elv_next_request(rq)) != NULL) {
if (!blk_fs_request(req)) {
+ if (blk_pc_request(req)) {
+ req->errors = (DID_ERROR << 16)
+ | (DRIVER_INVALID << 24);
+ req->hard_cur_sectors = (req->data_len
+ + 511) >> 9;
+ }
end_request(req, 0);
continue;
}
@@ -912,9 +919,16 @@ blktap_device_do_request(request_queue_t
fail:
while ((req = elv_next_request(rq))) {
- BTERR("device closed: failing secs %llu - %llu\n",
- (unsigned long long)req->sector,
- (unsigned long long)req->sector + req->nr_sectors);
+ if (blk_fs_request(req)) {
+ unsigned long long sec = req->sector;
+
+ BTERR("device closed: failing secs %#Lx-%#Lx\n",
+ sec, sec + req->nr_sectors - 1);
+ } else if (blk_pc_request(req)) {
+ req->errors = (DID_ERROR << 16)
+ | (DRIVER_INVALID << 24);
+ req->hard_cur_sectors = (req->data_len + 511) >> 9;
+ }
end_request(req, 0);
}
}
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