Commit 56b4f06c authored by Damien Le Moal's avatar Damien Le Moal Committed by Jens Axboe
Browse files

libata: simplify ata_scsi_rbuf_fill() 



Sparse complains about context imbalance in ata_scsi_rbuf_get() and
ata_scsi_rbuf_put() due to these functions respectively only taking
and releasing the ata_scsi_rbuf_lock spinlock. Since these functions are
only called from ata_scsi_rbuf_fill() with ata_scsi_rbuf_get() being
called with a copy_in argument always false, the code can be simplified
and ata_scsi_rbuf_{get|put} removed. This change both simplifies the
code and fixes the sparse warning.

Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210816014456.2191776-4-damien.lemoal@wdc.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 355a8031

drivers/ata/libata-scsi.c

+9 −51
Original line number Diff line number Diff line
@@ -1765,53 +1765,6 @@ struct ata_scsi_args { 
	struct scsi_cmnd	*cmd;

};



/**

 *	ata_scsi_rbuf_get - Map response buffer.

 *	@cmd: SCSI command containing buffer to be mapped.

 *	@flags: unsigned long variable to store irq enable status

 *	@copy_in: copy in from user buffer

 *

 *	Prepare buffer for simulated SCSI commands.

 *

 *	LOCKING:

 *	spin_lock_irqsave(ata_scsi_rbuf_lock) on success

 *

 *	RETURNS:

 *	Pointer to response buffer.

 */

static void *ata_scsi_rbuf_get(struct scsi_cmnd *cmd, bool copy_in,

			       unsigned long *flags)

{

	spin_lock_irqsave(&ata_scsi_rbuf_lock, *flags);



	memset(ata_scsi_rbuf, 0, ATA_SCSI_RBUF_SIZE);

	if (copy_in)

		sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),

				  ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);

	return ata_scsi_rbuf;

}



/**

 *	ata_scsi_rbuf_put - Unmap response buffer.

 *	@cmd: SCSI command containing buffer to be unmapped.

 *	@copy_out: copy out result

 *	@flags: @flags passed to ata_scsi_rbuf_get()

 *

 *	Returns rbuf buffer.  The result is copied to @cmd's buffer if

 *	@copy_back is true.

 *

 *	LOCKING:

 *	Unlocks ata_scsi_rbuf_lock.

 */

static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, bool copy_out,

				     unsigned long *flags)

{

	if (copy_out)

		sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),

				    ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);

	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, *flags);

}



/**

 *	ata_scsi_rbuf_fill - wrapper for SCSI command simulators

 *	@args: device IDENTIFY data / SCSI command of interest.
@@ -1830,14 +1783,19 @@ static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, bool copy_out, 
static void ata_scsi_rbuf_fill(struct ata_scsi_args *args,

		unsigned int (*actor)(struct ata_scsi_args *args, u8 *rbuf))

{

	u8 *rbuf;

	unsigned int rc;

	struct scsi_cmnd *cmd = args->cmd;

	unsigned long flags;



	rbuf = ata_scsi_rbuf_get(cmd, false, &flags);

	rc = actor(args, rbuf);

	ata_scsi_rbuf_put(cmd, rc == 0, &flags);

	spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);



	memset(ata_scsi_rbuf, 0, ATA_SCSI_RBUF_SIZE);

	rc = actor(args, ata_scsi_rbuf);

	if (rc == 0)

		sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),

				    ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);



	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);



	if (rc == 0)

		cmd->result = SAM_STAT_GOOD;