diff options
| author | Douglas Gilbert <dgilbert@interlog.com> | 2014-10-19 00:11:21 +0400 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-11-12 13:15:54 +0300 |
| commit | 26cf591e6dfc0d07495b7bcf20a557b316811f00 (patch) | |
| tree | aaebbfe8c9764f981f2fa540b6ae20c79dce55af /include/scsi | |
| parent | 678e27573237a0b065defdf99e5070c9b0c403c3 (diff) | |
| download | linux-26cf591e6dfc0d07495b7bcf20a557b316811f00.tar.xz | |
scsi: add SG_SCSI_RESET_NO_ESCALATE flag to SG_SCSI_RESET ioctl
Further to a January 2013 thread titled: "[PATCH] SG_SCSI_RESET ioctl
should only perform requested operation" by Jeremy Linton a patch (v3)
is presented that expands the existing ioctl to include "no_escalate"
versions to the existing resets. This requires no changes to SCSI low
level drivers (LLDs); it adds several more finely tuned reset options
to the user space. For example:
/* This call remains the same, with the same escalating semantics
* if the device (LU) reset fail. That is: on failure to try a
* target reset and if that fails, try a bus reset, and if that fails
* try a host (i.e. LLD) reset. */
val = SG_SCSI_RESET_DEVICE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);
/* What follows is a new option introduced by this patch series. Only
* a device reset is attempted. If that fails then an appropriate
* error code is provided. N.B. There is no reset escalation. */
val = SG_SCSI_RESET_DEVICE | SG_SCSI_RESET_NO_ESCALATE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Jeremy Linton <jlinton@tributary.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/scsi')
| -rw-r--r-- | include/scsi/scsi_eh.h | 5 | ||||
| -rw-r--r-- | include/scsi/sg.h | 5 |
2 files changed, 9 insertions, 1 deletions
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h index 06a8790893ef..49af14ad5288 100644 --- a/include/scsi/scsi_eh.h +++ b/include/scsi/scsi_eh.h @@ -62,11 +62,16 @@ extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq); /* * Reset request from external source + * Note: if SCSI_TRY_RESET_DEVICE fails then it will escalate to + * SCSI_TRY_RESET_TARGET which if it fails will escalate to + * SCSI_TRY_RESET_BUS which if it fails will escalate to SCSI_TRY_RESET_HOST. + * To prevent escalation OR with SCSI_TRY_RESET_NO_ESCALATE. */ #define SCSI_TRY_RESET_DEVICE 1 #define SCSI_TRY_RESET_BUS 2 #define SCSI_TRY_RESET_HOST 3 #define SCSI_TRY_RESET_TARGET 4 +#define SCSI_TRY_RESET_NO_ESCALATE 0x100 /* OR-ed to prior defines */ extern int scsi_reset_provider(struct scsi_device *, int); diff --git a/include/scsi/sg.h b/include/scsi/sg.h index 750e5db7c6bf..3afec7032448 100644 --- a/include/scsi/sg.h +++ b/include/scsi/sg.h @@ -164,12 +164,15 @@ typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */ /* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */ #define SG_SCSI_RESET 0x2284 -/* Associated values that can be given to SG_SCSI_RESET follow */ +/* Associated values that can be given to SG_SCSI_RESET follow. + * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS + * or _HOST reset value so only that action is attempted. */ #define SG_SCSI_RESET_NOTHING 0 #define SG_SCSI_RESET_DEVICE 1 #define SG_SCSI_RESET_BUS 2 #define SG_SCSI_RESET_HOST 3 #define SG_SCSI_RESET_TARGET 4 +#define SG_SCSI_RESET_NO_ESCALATE 0x100 /* synchronous SCSI command ioctl, (only in version 3 interface) */ #define SG_IO 0x2285 /* similar effect as write() followed by read() */ |