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| author | Douglas Gilbert <dgilbert@interlog.com> | 2014-10-18 22:11:21 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-11-12 11:15:54 +0100 |
| commit | 26cf591e6dfc0d07495b7bcf20a557b316811f00 (patch) | |
| tree | aaebbfe8c9764f981f2fa540b6ae20c79dce55af /drivers/scsi/scsi_ioctl.c | |
| parent | scsi: PC partition tables are little endian (diff) | |
| download | linux-26cf591e6dfc0d07495b7bcf20a557b316811f00.tar.xz linux-26cf591e6dfc0d07495b7bcf20a557b316811f00.zip | |
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 'drivers/scsi/scsi_ioctl.c')
| -rw-r--r-- | drivers/scsi/scsi_ioctl.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c index 1aaaf43c6803..12fe676d1343 100644 --- a/drivers/scsi/scsi_ioctl.c +++ b/drivers/scsi/scsi_ioctl.c @@ -285,13 +285,14 @@ EXPORT_SYMBOL(scsi_ioctl); * scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET * @sdev: scsi device receiving ioctl * @cmd: Must be SC_SCSI_RESET - * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,BUS,HOST} + * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,TARGET,BUS,HOST} + * possibly OR-ed with SG_SCSI_RESET_NO_ESCALATE * @ndelay: file mode O_NDELAY flag */ int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd, void __user *arg, int ndelay) { - int val, result; + int val, val2, result; /* The first set of iocts may be executed even if we're doing * error processing, as long as the device was opened @@ -307,27 +308,32 @@ int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd, result = get_user(val, (int __user *)arg); if (result) return result; + if (val & SG_SCSI_RESET_NO_ESCALATE) { + val &= ~SG_SCSI_RESET_NO_ESCALATE; + val2 = SCSI_TRY_RESET_NO_ESCALATE; + } else + val2 = 0; if (val == SG_SCSI_RESET_NOTHING) return 0; switch (val) { case SG_SCSI_RESET_DEVICE: - val = SCSI_TRY_RESET_DEVICE; + val2 |= SCSI_TRY_RESET_DEVICE; break; case SG_SCSI_RESET_TARGET: - val = SCSI_TRY_RESET_TARGET; + val2 |= SCSI_TRY_RESET_TARGET; break; case SG_SCSI_RESET_BUS: - val = SCSI_TRY_RESET_BUS; + val2 |= SCSI_TRY_RESET_BUS; break; case SG_SCSI_RESET_HOST: - val = SCSI_TRY_RESET_HOST; + val2 |= SCSI_TRY_RESET_HOST; break; default: return -EINVAL; } if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; - return (scsi_reset_provider(sdev, val) == + return (scsi_reset_provider(sdev, val2) == SUCCESS) ? 0 : -EIO; } return -ENODEV; |