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authorDouglas Gilbert <dgilbert@interlog.com>2014-10-19 00:11:21 +0400
committerChristoph Hellwig <hch@lst.de>2014-11-12 13:15:54 +0300
commit26cf591e6dfc0d07495b7bcf20a557b316811f00 (patch)
treeaaebbfe8c9764f981f2fa540b6ae20c79dce55af /include/scsi/scsi_eh.h
parent678e27573237a0b065defdf99e5070c9b0c403c3 (diff)
downloadlinux-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/scsi_eh.h')
-rw-r--r--include/scsi/scsi_eh.h5
1 files changed, 5 insertions, 0 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);