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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH LDI_OPEN_BY_DEV 9F "September 22, 2020" .SH NAME ldi_open_by_dev, ldi_open_by_name, ldi_open_by_devid, ldi_close \- open and close devices .SH SYNOPSIS .nf #include \fBint\fR \fBldi_open_by_dev\fR(\fBdev_t *\fR\fIdevp\fR, \fBint\fR \fIotyp\fR, \fBint\fR \fIflag\fR, \fBcred_t *\fR\fIcr\fR, \fBldi_handle_t *\fR\fIlhp\fR, \fBldi_ident_t\fR \fIli\fR); .fi .LP .nf \fBint\fR \fBldi_open_by_name\fR(\fBchar *\fR\fIpathname\fR, \fBint\fR \fIflag\fR, \fBcred_t *\fR\fIcr\fR, \fBldi_handle_t *\fR\fIlhp\fR, \fBldi_ident_t\fR \fIli\fR); .fi .LP .nf \fBint\fR \fBldi_open_by_devid\fR(\fBddi_devid_t\fR \fIdevid\fR, \fBchar *\fR\fIminor_name\fR, \fBint\fR \fIflag\fR, \fBcred_t *\fR\fIcr\fR, \fBldi_handle_t *\fR\fIlhp\fR, \fBldi_ident_t\fR \fIli\fR); .fi .LP .nf \fBint\fR \fBldi_close\fR(\fBldi_handle_t\fR \fIlh\fR, \fBint\fR \fIflag\fR, \fBcred_t *\fR\fIcr\fR); .fi .SH PARAMETERS .ne 2 .na \fB\fIlh\fR\fR .ad .RS 14n Layered handle .RE .sp .ne 2 .na \fB\fIlhp\fR\fR .ad .RS 14n Pointer to a layered handle that is returned upon a successful open. .RE .sp .ne 2 .na \fB\fIli\fR\fR .ad .RS 14n LDI identifier. .RE .sp .ne 2 .na \fB\fIcr\fR\fR .ad .RS 14n Pointer to the credential structure used to open a device. .RE .sp .ne 2 .na \fB\fIdevp\fR\fR .ad .RS 14n Pointer to a device number. .RE .sp .ne 2 .na \fB\fIpathname\fR\fR .ad .RS 14n Pathname to a device. .RE .sp .ne 2 .na \fB\fIdevid\fR\fR .ad .RS 14n Device ID. .RE .sp .ne 2 .na \fB\fIminor_name\fR\fR .ad .RS 14n Minor device node name. .RE .sp .ne 2 .na \fB\fIotyp\fR\fR .ad .RS 14n Flag passed to the driver indicating which interface is open. Valid settings are: .sp .ne 2 .na \fBOTYP_BLK\fR .ad .RS 12n Open the device block interface. .RE .sp .ne 2 .na \fBOTYP_CHR\fR .ad .RS 12n Open the device character interface. .RE Only one OTYP flag can be specified. To open streams devices, specify \fBOTYP_CHR\fR. .RE .sp .ne 2 .na \fB\fIflag\fR\fR .ad .RS 14n Bit field that instructs the driver on how to open the device. Valid settings are: .sp .ne 2 .na \fBFEXCL\fR .ad .RS 11n Open the device with exclusive access; fail all other attempts to open the device. .RE .sp .ne 2 .na \fBFNDELAY\fR .ad .RS 11n Open the device and return immediately. Do not block the open even if something is wrong. .RE .sp .ne 2 .na \fBFREAD\fR .ad .RS 11n Open the device with read-only permission. (If ORed with \fBFWRITE\fR, allow both read and write access). .RE .sp .ne 2 .na \fBFWRITE\fR .ad .RS 11n Open a device with write-only permission (if ORed with \fBFREAD\fR, then allow both read and write access). .RE .sp .ne 2 .na \fBFNOCTTY\fR .ad .RS 11n Open the device. If the device is a tty, do not attempt to open it as a session-controlling tty. .RE .RE .SH DESCRIPTION The \fBldi_open_by_dev()\fR, \fBldi_open_by_name()\fR and \fBldi_open_by_devid()\fR functions allow a caller to open a block, character, or streams device. Upon a successful open, a layered handle to the device is returned via the layered handle pointed to by \fIlhp\fR. The ldi identifier passed to these functions is previously allocated with \fBldi_ident_from_stream\fR(9F), \fBldi_ident_from_dev\fR(9F), and \fBldi_ident_from_dip\fR(9F). .sp .LP The \fBldi_open_by_dev()\fR function opens a device specified by the dev_t pointed to by devp. Upon successful open, the caller should check the value of the dev_t to see if it has changed. (Cloning devices will change this value during opens.) When opening a streams device, otyp must be OTYP_CHR. .sp .LP The \fBldi_open_by_devid()\fR function opens a device by devid. The caller must specify the minor node name to open. .sp .LP The \fBldi_open_by_name()\fR function opens a device by pathname. Pathname is a null terminated string in the kernel address space. Pathname must be an absolute path, meaning that it must begin with '/'. The format of the pathname supplied to this function is either a \fB/devices\fR path or any other filesystem path to a device node. Opens utilizing \fB/devices\fR paths are supported before root is mounted. Opens utilizing other filesystem paths to device nodes are supported only if root is already mounted. .sp .LP The \fBldi_close()\fR function closes a layered handle that was obtained with either \fBldi_open_by_dev()\fR, \fBldi_open_by_name()\fR, or \fBldi_open_by_devid()\fR. After \fBldi_close()\fR returns the layered handle, the \fIlh\fR that was previously passed in is no longer valid. .SH RETURN VALUES The \fBldi_close()\fR function returns \fB0\fR for success. \fBEINVAL\fR is returned for invalid input parameters. Otherwise, any other error number may be returned by the device. .sp .LP The \fBldi_open_by_dev()\fR and \fBldi_open_by_devid()\fR functions return \fB0\fR upon success. If a failure occurs before the device is open, possible return values are shown below. Otherwise any other error number may be returned by the device. .sp .ne 2 .na \fBEINVAL\fR .ad .RS 10n Invalid input parameters. .RE .sp .ne 2 .na \fBENODEV\fR .ad .RS 10n Requested device does not exist. .RE .sp .ne 2 .na \fBENXIO\fR .ad .RS 10n Unsupported device operation or access mode. .RE .sp .LP The \fBldi_open_by_name()\fR function returns \fB0\fR upon success. If a failure occurs before the device is open, possible return values are shown below. Otherwise any other error number may be returned by the device. .sp .ne 2 .na \fBEINVAL\fR .ad .RS 10n Invalid input parameters. .RE .sp .ne 2 .na \fBENODEV\fR .ad .RS 10n Requested device path does not exist. .RE .sp .ne 2 .na \fBEACCES\fR .ad .RS 10n Search permission is denied on a component of the path prefix, or the file exists and the permissions specified by \fIcr\fR are denied. .RE .sp .ne 2 .na \fBENXIO\fR .ad .RS 10n Unsupported device operation or access mode. .RE .SH CONTEXT These functions may be called from user or kernel context. .sp .LP These functions should not be called from a device's attach, detach, or power entry point. This could result in a system crash or deadlock. .SH SEE ALSO .BR scsi_vhci (4D), .BR ldi_ident_from_dev (9F), .BR ldi_ident_from_dip (9F), .BR ldi_ident_from_stream (9F) .SH NOTES Use only OTYP_CHR or OTYP_BLK options when you use the \fBldi_open_by_dev()\fR and \fBldi_open_by_devid()\fR functions to open a device. Other flags, including OTYP_LYR, have been deprecated and should not be used with these interfaces. .sp .LP The caller should be aware of cases when multiple paths to a single device may exist. (This can occur for scsi disk devices if \fBscsi_vhci\fR(4D)) is disabled or a disk is connected to multiple controllers not supported by scsi_vhci(4D). .sp .LP In these cases, \fBldi_open_by_devid()\fR returns a device handle that corresponds to a particular path to a target device. This path may not be the same across multiple calls to \fBldi_open_by_devid()\fR. Device handles associated with the same device but different access paths should have different filesystem device paths and dev_t values. .sp .LP In the cases where multiple paths to a device exist and access to the device has not been virtualized via MPXIO (as with scsi disk devices not accessed via \fBscsi_vhci\fR(4D)), the LDI does not provide any path fail-over capabilities. If the caller wishes to do their own path management and failover they should open all available paths to a device via \fBldi_open_by_name()\fR.