rbd: define and use rbd_warn()

Define a new function rbd_warn() that produces a boilerplate warning
message, identifying in the resulting message the affected rbd
device in the best way available.  Use it in a few places that now
use pr_warning().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index d97611e2b4ee319c1431f8e57d41c007f3537e6b..635b81d0ebdb51dff242f1832e51005d299d3789 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -294,6 +294,33 @@ static struct device rbd_root_dev = {
        .release =      rbd_root_dev_release,
 };
 
+static __printf(2, 3)
+void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
+{
+       struct va_format vaf;
+       va_list args;
+
+       va_start(args, fmt);
+       vaf.fmt = fmt;
+       vaf.va = &args;
+
+       if (!rbd_dev)
+               printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
+       else if (rbd_dev->disk)
+               printk(KERN_WARNING "%s: %s: %pV\n",
+                       RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
+       else if (rbd_dev->spec && rbd_dev->spec->image_name)
+               printk(KERN_WARNING "%s: image %s: %pV\n",
+                       RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
+       else if (rbd_dev->spec && rbd_dev->spec->image_id)
+               printk(KERN_WARNING "%s: id %s: %pV\n",
+                       RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
+       else    /* punt */
+               printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
+                       RBD_DRV_NAME, rbd_dev, &vaf);
+       va_end(args);
+}
+
 #ifdef RBD_DEBUG
 #define rbd_assert(expr)                                               \
                if (unlikely(!(expr))) {                                \
@@ -1403,8 +1430,8 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
                (unsigned int) opcode);
        rc = rbd_dev_refresh(rbd_dev, &hver);
        if (rc)
-               pr_warning(RBD_DRV_NAME "%d got notification but failed to "
-                          " update snaps: %d\n", rbd_dev->major, rc);
+               rbd_warn(rbd_dev, "got notification but failed to "
+                          " update snaps: %d\n", rc);
 
        rbd_req_sync_notify_ack(rbd_dev, hver, notify_id);
 }
@@ -1767,15 +1794,13 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev, u64 *version)
                        goto out_err;
                if (WARN_ON((size_t) ret < size)) {
                        ret = -ENXIO;
-                       pr_warning("short header read for image %s"
-                                       " (want %zd got %d)\n",
-                               rbd_dev->spec->image_name, size, ret);
+                       rbd_warn(rbd_dev, "short header read (want %zd got %d)",
+                               size, ret);
                        goto out_err;
                }
                if (!rbd_dev_ondisk_valid(ondisk)) {
                        ret = -ENXIO;
-                       pr_warning("invalid header for image %s\n",
-                               rbd_dev->spec->image_name);
+                       rbd_warn(rbd_dev, "invalid header");
                        goto out_err;
                }
 
@@ -2630,9 +2655,7 @@ static int rbd_dev_probe_update_spec(struct rbd_device *rbd_dev)
        if (name)
                rbd_dev->spec->image_name = (char *) name;
        else
-               pr_warning(RBD_DRV_NAME "%d "
-                       "unable to get image name for image id %s\n",
-                       rbd_dev->major, rbd_dev->spec->image_id);
+               rbd_warn(rbd_dev, "unable to get image name");
 
        /* Look up the snapshot name. */