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: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210816014456.2191776-4-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b9588c5..0b7b462 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -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;