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| author | Tony Battersby <tonyb@cybernetics.com> | 2018-07-13 01:09:21 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2018-07-13 06:08:13 +0300 |
| commit | 8e4a4189ce02fe53b6f3ffcc1ac5a3a9967f2611 (patch) | |
| tree | 3f6b5889459eeb41e8b16a3b84f0edbdb6b84f2d /drivers | |
| parent | c170e5a8d222537e98aa8d4fddb667ff7a2ee114 (diff) | |
| download | linux-8e4a4189ce02fe53b6f3ffcc1ac5a3a9967f2611.tar.xz | |
scsi: sg: update comment for blk_get_request()
The calling convention of blk_get_request() has changed in lk 4.18; update
the comment in sg.c to match.
Fixes: ff005a066240 ("block: sanitize blk_get_request calling conventions")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/sg.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 2962a38c5068..ba9ba0e04f42 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1741,15 +1741,11 @@ sg_start_req(Sg_request *srp, unsigned char *cmd) * * With scsi-mq enabled, there are a fixed number of preallocated * requests equal in number to shost->can_queue. If all of the - * preallocated requests are already in use, then using GFP_ATOMIC with - * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL - * will cause blk_get_request() to sleep until an active command - * completes, freeing up a request. Neither option is ideal, but - * GFP_KERNEL is the better choice to prevent userspace from getting an - * unexpected EWOULDBLOCK. - * - * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually - * does not sleep except under memory pressure. + * preallocated requests are already in use, then blk_get_request() + * will sleep until an active command completes, freeing up a request. + * Although waiting in an asynchronous interface is less than ideal, we + * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might + * not expect an EWOULDBLOCK from this condition. */ rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0); |