Btrfs: Include the device in most error printk()s

With more than one btrfs volume mounted, it can be very difficult to find
out which volume is hitting an error. btrfs_error() will print this, but
it is currently rigged as more of a fatal error handler, while many of
the printk()s are currently for debugging and yet-unhandled cases.

This patch just changes the functions where the device information is
already available. Some cases remain where the root or fs_info is not
passed to the function emitting the error.

This may introduce some confusion with volumes backed by multiple devices
emitting errors referring to the primary device in the set instead of the
one on which the error occurred.

Use btrfs_printk(fs_info, format, ...) rather than writing the device
string every time, and introduce macro wrappers ala XFS for brevity.
Since the function already cannot be used for continuations, print a
newline as part of the btrfs_printk() message rather than at each caller.

Signed-off-by: Simon Kirby <sim@hostway.ca>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index efb2feb..5060990 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3643,14 +3643,31 @@
 
 #ifdef CONFIG_PRINTK
 __printf(2, 3)
-void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...);
+void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
 #else
 static inline __printf(2, 3)
-void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
+void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 {
 }
 #endif
 
+#define btrfs_emerg(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_EMERG fmt, ##args)
+#define btrfs_alert(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_ALERT fmt, ##args)
+#define btrfs_crit(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_CRIT fmt, ##args)
+#define btrfs_err(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_ERR fmt, ##args)
+#define btrfs_warn(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_WARNING fmt, ##args)
+#define btrfs_notice(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_NOTICE fmt, ##args)
+#define btrfs_info(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_INFO fmt, ##args)
+#define btrfs_debug(fs_info, fmt, args...) \
+	btrfs_printk(fs_info, KERN_DEBUG fmt, ##args)
+
 __printf(5, 6)
 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 		     unsigned int line, int errno, const char *fmt, ...);