[SCSI] Add Documentation and integrate into docbook build
Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update lots of kerneldoc comments in drivers/scsi/*. Updated with comments from Stefan Richter, Stephen M. Cameron, James Bottomley and Randy Dunlap. Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
这个提交包含在:
@@ -122,6 +122,11 @@ static const char *const scsi_device_types[] = {
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"Automation/Drive ",
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};
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/**
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* scsi_device_type - Return 17 char string indicating device type.
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* @type: type number to look up
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*/
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const char * scsi_device_type(unsigned type)
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{
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if (type == 0x1e)
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@@ -156,6 +161,14 @@ static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
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static DEFINE_MUTEX(host_cmd_pool_mutex);
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/**
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* __scsi_get_command - Allocate a struct scsi_cmnd
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* @shost: host to transmit command
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* @gfp_mask: allocation mask
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*
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* Description: allocate a struct scsi_cmd from host's slab, recycling from the
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* host's free_list if necessary.
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*/
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struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
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{
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struct scsi_cmnd *cmd;
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@@ -179,13 +192,10 @@ struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
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}
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EXPORT_SYMBOL_GPL(__scsi_get_command);
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/*
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* Function: scsi_get_command()
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*
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* Purpose: Allocate and setup a scsi command block
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*
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* Arguments: dev - parent scsi device
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* gfp_mask- allocator flags
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/**
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* scsi_get_command - Allocate and setup a scsi command block
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* @dev: parent scsi device
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* @gfp_mask: allocator flags
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*
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* Returns: The allocated scsi command structure.
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*/
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@@ -217,6 +227,12 @@ struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
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}
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EXPORT_SYMBOL(scsi_get_command);
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/**
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* __scsi_put_command - Free a struct scsi_cmnd
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* @shost: dev->host
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* @cmd: Command to free
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* @dev: parent scsi device
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*/
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void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
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struct device *dev)
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{
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@@ -237,12 +253,9 @@ void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
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}
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EXPORT_SYMBOL(__scsi_put_command);
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/*
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* Function: scsi_put_command()
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*
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* Purpose: Free a scsi command block
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*
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* Arguments: cmd - command block to free
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/**
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* scsi_put_command - Free a scsi command block
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* @cmd: command block to free
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*
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* Returns: Nothing.
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*
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@@ -263,12 +276,13 @@ void scsi_put_command(struct scsi_cmnd *cmd)
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}
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EXPORT_SYMBOL(scsi_put_command);
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/*
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* Function: scsi_setup_command_freelist()
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/**
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* scsi_setup_command_freelist - Setup the command freelist for a scsi host.
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* @shost: host to allocate the freelist for.
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*
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* Purpose: Setup the command freelist for a scsi host.
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*
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* Arguments: shost - host to allocate the freelist for.
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* Description: The command freelist protects against system-wide out of memory
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* deadlock by preallocating one SCSI command structure for each host, so the
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* system can always write to a swap file on a device associated with that host.
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*
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* Returns: Nothing.
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*/
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@@ -282,7 +296,7 @@ int scsi_setup_command_freelist(struct Scsi_Host *shost)
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/*
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* Select a command slab for this host and create it if not
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* yet existant.
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* yet existent.
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*/
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mutex_lock(&host_cmd_pool_mutex);
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pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool);
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@@ -318,12 +332,9 @@ int scsi_setup_command_freelist(struct Scsi_Host *shost)
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}
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/*
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* Function: scsi_destroy_command_freelist()
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*
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* Purpose: Release the command freelist for a scsi host.
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*
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* Arguments: shost - host that's freelist is going to be destroyed
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/**
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* scsi_destroy_command_freelist - Release the command freelist for a scsi host.
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* @shost: host whose freelist is going to be destroyed
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*/
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void scsi_destroy_command_freelist(struct Scsi_Host *shost)
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{
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@@ -441,8 +452,12 @@ void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
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}
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#endif
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/*
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* Assign a serial number to the request for error recovery
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/**
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* scsi_cmd_get_serial - Assign a serial number to a command
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* @host: the scsi host
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* @cmd: command to assign serial number to
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*
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* Description: a serial number identifies a request for error recovery
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* and debugging purposes. Protected by the Host_Lock of host.
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*/
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static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
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@@ -452,14 +467,12 @@ static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd
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cmd->serial_number = host->cmd_serial_number++;
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}
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/*
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* Function: scsi_dispatch_command
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/**
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* scsi_dispatch_command - Dispatch a command to the low-level driver.
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* @cmd: command block we are dispatching.
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*
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* Purpose: Dispatch a command to the low-level driver.
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*
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* Arguments: cmd - command block we are dispatching.
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*
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* Notes:
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* Return: nonzero return request was rejected and device's queue needs to be
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* plugged.
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*/
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int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
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{
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@@ -585,7 +598,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
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/**
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* scsi_req_abort_cmd -- Request command recovery for the specified command
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* cmd: pointer to the SCSI command of interest
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* @cmd: pointer to the SCSI command of interest
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*
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* This function requests that SCSI Core start recovery for the
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* command by deleting the timer and adding the command to the eh
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@@ -606,9 +619,9 @@ EXPORT_SYMBOL(scsi_req_abort_cmd);
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* @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
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* ownership back to SCSI Core -- i.e. the LLDD has finished with it.
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*
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* This function is the mid-level's (SCSI Core) interrupt routine, which
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* regains ownership of the SCSI command (de facto) from a LLDD, and enqueues
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* the command to the done queue for further processing.
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* Description: This function is the mid-level's (SCSI Core) interrupt routine,
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* which regains ownership of the SCSI command (de facto) from a LLDD, and
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* enqueues the command to the done queue for further processing.
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*
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* This is the producer of the done queue who enqueues at the tail.
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*
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@@ -617,7 +630,7 @@ EXPORT_SYMBOL(scsi_req_abort_cmd);
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static void scsi_done(struct scsi_cmnd *cmd)
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{
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/*
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* We don't have to worry about this one timing out any more.
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* We don't have to worry about this one timing out anymore.
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* If we are unable to remove the timer, then the command
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* has already timed out. In which case, we have no choice but to
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* let the timeout function run, as we have no idea where in fact
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@@ -660,10 +673,11 @@ static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
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return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
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}
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/*
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* Function: scsi_finish_command
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/**
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* scsi_finish_command - cleanup and pass command back to upper layer
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* @cmd: the command
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*
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* Purpose: Pass command off to upper layer for finishing of I/O
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* Description: Pass command off to upper layer for finishing of I/O
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* request, waking processes that are waiting on results,
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* etc.
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*/
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@@ -708,18 +722,14 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
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}
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EXPORT_SYMBOL(scsi_finish_command);
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/*
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* Function: scsi_adjust_queue_depth()
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*
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* Purpose: Allow low level drivers to tell us to change the queue depth
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* on a specific SCSI device
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*
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* Arguments: sdev - SCSI Device in question
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* tagged - Do we use tagged queueing (non-0) or do we treat
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* this device as an untagged device (0)
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* tags - Number of tags allowed if tagged queueing enabled,
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* or number of commands the low level driver can
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* queue up in non-tagged mode (as per cmd_per_lun).
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/**
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* scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
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* @sdev: SCSI Device in question
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* @tagged: Do we use tagged queueing (non-0) or do we treat
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* this device as an untagged device (0)
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* @tags: Number of tags allowed if tagged queueing enabled,
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* or number of commands the low level driver can
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* queue up in non-tagged mode (as per cmd_per_lun).
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*
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* Returns: Nothing
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*
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@@ -742,8 +752,8 @@ void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
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spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
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/* Check to see if the queue is managed by the block layer
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* if it is, and we fail to adjust the depth, exit */
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/* Check to see if the queue is managed by the block layer.
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* If it is, and we fail to adjust the depth, exit. */
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if (blk_queue_tagged(sdev->request_queue) &&
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blk_queue_resize_tags(sdev->request_queue, tags) != 0)
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goto out;
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@@ -772,20 +782,17 @@ void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
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}
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EXPORT_SYMBOL(scsi_adjust_queue_depth);
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/*
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* Function: scsi_track_queue_full()
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/**
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* scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
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* @sdev: SCSI Device in question
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* @depth: Current number of outstanding SCSI commands on this device,
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* not counting the one returned as QUEUE_FULL.
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*
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* Purpose: This function will track successive QUEUE_FULL events on a
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* Description: This function will track successive QUEUE_FULL events on a
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* specific SCSI device to determine if and when there is a
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* need to adjust the queue depth on the device.
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*
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* Arguments: sdev - SCSI Device in question
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* depth - Current number of outstanding SCSI commands on
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* this device, not counting the one returned as
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* QUEUE_FULL.
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*
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* Returns: 0 - No change needed
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* >0 - Adjust queue depth to this new depth
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* Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
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* -1 - Drop back to untagged operation using host->cmd_per_lun
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* as the untagged command depth
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*
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@@ -824,10 +831,10 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
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EXPORT_SYMBOL(scsi_track_queue_full);
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/**
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* scsi_device_get - get an addition reference to a scsi_device
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* scsi_device_get - get an additional reference to a scsi_device
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* @sdev: device to get a reference to
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*
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* Gets a reference to the scsi_device and increments the use count
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* Description: Gets a reference to the scsi_device and increments the use count
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* of the underlying LLDD module. You must hold host_lock of the
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* parent Scsi_Host or already have a reference when calling this.
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*/
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@@ -849,8 +856,8 @@ EXPORT_SYMBOL(scsi_device_get);
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* scsi_device_put - release a reference to a scsi_device
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* @sdev: device to release a reference on.
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*
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* Release a reference to the scsi_device and decrements the use count
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* of the underlying LLDD module. The device is freed once the last
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* Description: Release a reference to the scsi_device and decrements the use
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* count of the underlying LLDD module. The device is freed once the last
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* user vanishes.
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*/
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void scsi_device_put(struct scsi_device *sdev)
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@@ -867,7 +874,7 @@ void scsi_device_put(struct scsi_device *sdev)
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}
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EXPORT_SYMBOL(scsi_device_put);
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/* helper for shost_for_each_device, thus not documented */
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/* helper for shost_for_each_device, see that for documentation */
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struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
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struct scsi_device *prev)
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{
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@@ -895,6 +902,8 @@ EXPORT_SYMBOL(__scsi_iterate_devices);
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/**
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* starget_for_each_device - helper to walk all devices of a target
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* @starget: target whose devices we want to iterate over.
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* @data: Opaque passed to each function call.
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* @fn: Function to call on each device
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*
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* This traverses over each device of @starget. The devices have
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* a reference that must be released by scsi_host_put when breaking
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@@ -946,13 +955,13 @@ EXPORT_SYMBOL(__starget_for_each_device);
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* @starget: SCSI target pointer
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* @lun: SCSI Logical Unit Number
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*
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* Looks up the scsi_device with the specified @lun for a give
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* @starget. The returned scsi_device does not have an additional
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* Description: Looks up the scsi_device with the specified @lun for a given
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* @starget. The returned scsi_device does not have an additional
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* reference. You must hold the host's host_lock over this call and
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* any access to the returned scsi_device.
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*
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* Note: The only reason why drivers would want to use this is because
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* they're need to access the device list in irq context. Otherwise you
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* they need to access the device list in irq context. Otherwise you
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* really want to use scsi_device_lookup_by_target instead.
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**/
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struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
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@@ -974,9 +983,9 @@ EXPORT_SYMBOL(__scsi_device_lookup_by_target);
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* @starget: SCSI target pointer
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* @lun: SCSI Logical Unit Number
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*
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* Looks up the scsi_device with the specified @channel, @id, @lun for a
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* give host. The returned scsi_device has an additional reference that
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* needs to be release with scsi_host_put once you're done with it.
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* Description: Looks up the scsi_device with the specified @channel, @id, @lun
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* for a given host. The returned scsi_device has an additional reference that
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* needs to be released with scsi_device_put once you're done with it.
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**/
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struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
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uint lun)
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@@ -996,19 +1005,19 @@ struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
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EXPORT_SYMBOL(scsi_device_lookup_by_target);
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/**
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* scsi_device_lookup - find a device given the host (UNLOCKED)
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* __scsi_device_lookup - find a device given the host (UNLOCKED)
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* @shost: SCSI host pointer
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* @channel: SCSI channel (zero if only one channel)
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* @pun: SCSI target number (physical unit number)
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* @id: SCSI target number (physical unit number)
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* @lun: SCSI Logical Unit Number
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*
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* Looks up the scsi_device with the specified @channel, @id, @lun for a
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* give host. The returned scsi_device does not have an additional reference.
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* You must hold the host's host_lock over this call and any access to the
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* returned scsi_device.
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* Description: Looks up the scsi_device with the specified @channel, @id, @lun
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* for a given host. The returned scsi_device does not have an additional
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* reference. You must hold the host's host_lock over this call and any access
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* to the returned scsi_device.
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*
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* Note: The only reason why drivers would want to use this is because
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* they're need to access the device list in irq context. Otherwise you
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* they need to access the device list in irq context. Otherwise you
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* really want to use scsi_device_lookup instead.
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**/
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struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
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@@ -1033,9 +1042,9 @@ EXPORT_SYMBOL(__scsi_device_lookup);
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* @id: SCSI target number (physical unit number)
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* @lun: SCSI Logical Unit Number
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*
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* Looks up the scsi_device with the specified @channel, @id, @lun for a
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* give host. The returned scsi_device has an additional reference that
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* needs to be release with scsi_host_put once you're done with it.
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* Description: Looks up the scsi_device with the specified @channel, @id, @lun
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* for a given host. The returned scsi_device has an additional reference that
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* needs to be released with scsi_device_put once you're done with it.
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**/
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struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
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uint channel, uint id, uint lun)
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|
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