scsi: Implement per-cpu logging buffer

Implement a per-cpu buffer for formatting messages to avoid line breaks
up under high load.  This patch implements scmd_printk() and
sdev_prefix_printk() using the per-cpu buffer and makes sdev_printk() a
wrapper for sdev_prefix_printk().

Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 8 insertions, 13 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 3a4edd1f7dbb..d1aad4d04334 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -230,9 +230,6 @@ struct scsi_dh_data {
 #define transport_class_to_sdev(class_dev) \
         to_scsi_device(class_dev->parent)
 
-#define sdev_printk(prefix, sdev, fmt, a...)    \
-        dev_printk(prefix, &(sdev)->sdev_gendev, fmt, ##a)
-
 #define sdev_dbg(sdev, fmt, a...) \
         dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
 
@@ -240,16 +237,14 @@ struct scsi_dh_data {
  * like scmd_printk, but the device name is passed in
  * as a string pointer
  */
-#define sdev_prefix_printk(l, sdev, p, fmt, a...)                       \
-        (p) ?                                                           \
-        sdev_printk(l, sdev, "[%s] " fmt, p, ##a) :                     \
-        sdev_printk(l, sdev, fmt, ##a)
-
-#define scmd_printk(prefix, scmd, fmt, a...)                            \
-        (scmd)->request->rq_disk ?                                      \
-        sdev_printk(prefix, (scmd)->device, "[%s] " fmt,                \
-                    (scmd)->request->rq_disk->disk_name, ##a) :         \
-        sdev_printk(prefix, (scmd)->device, fmt, ##a)
+extern int sdev_prefix_printk(const char *, const struct scsi_device *,
+                              const char *, const char *, ...);
+
+#define sdev_printk(l, sdev, fmt, a...)                         \
+        sdev_prefix_printk(l, sdev, NULL, fmt, ##a)
+
+extern int scmd_printk(const char *, const struct scsi_cmnd *,
+                       const char *, ...);
 
 #define scmd_dbg(scmd, fmt, a...)                                          \
         do {                                                               \