udf: Promote some debugging messages to udf_error

commit 7e273e3b upstream.

If there is a problem with a scratched disc or loader, it's valuable to know
which error occurred.

Convert some debug messages to udf_error, neaten those messages too.
Add the calculated tag checksum and the read checksum to error message.
Make udf_error a public function and move the logging prototypes together.
Original-patch-by: NamJae Jeon <linkinjeon@gmail.com>
Reviewed-by: NamJae Jeon <linkinjeon@gmail.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jan Kara <jack@suse.cz>
[wt: this one is only here to export udf_error() for next commit]
Signed-off-by: Willy Tarreau <w@1wt.eu>

fs/udf/misc.c

@@ -204,6 +204,7 @@ struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
 {
 	struct tag *tag_p;
 	struct buffer_head *bh = NULL;
+	u8 checksum;
 
 	/* Read the block */
 	if (block == 0xFFFFFFFF)
@@ -211,7 +212,7 @@ struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
 
 	bh = udf_tread(sb, block);
 	if (!bh) {
-		udf_debug("block=%d, location=%d: read failed\n",
+		udf_error(sb, __func__, "read failed, block=%u, location=%d\n",
 			  block, location);
 		return NULL;
 	}
@@ -227,15 +228,19 @@ struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
 	}
 
 	/* Verify the tag checksum */
-	if (udf_tag_checksum(tag_p) != tag_p->tagChecksum) {
-		printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
+	checksum = udf_tag_checksum(tag_p);
+	if (checksum != tag_p->tagChecksum) {
+		udf_error(sb, __func__,
+			  "tag checksum failed, block %u: 0x%02x != 0x%02x\n",
+			  block, checksum, tag_p->tagChecksum);
 		goto error_out;
 	}
 
 	/* Verify the tag version */
 	if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
 	    tag_p->descVersion != cpu_to_le16(0x0003U)) {
-		udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n",
+		udf_error(sb, __func__,
+			  "tag version 0x%04x != 0x0002 || 0x0003, block %u\n",
 			  le16_to_cpu(tag_p->descVersion), block);
 		goto error_out;
 	}

fs/udf/super.c

@@ -94,8 +94,6 @@ static void udf_close_lvid(struct super_block *);
 static unsigned int udf_count_free(struct super_block *);
 static int udf_statfs(struct dentry *, struct kstatfs *);
 static int udf_show_options(struct seq_file *, struct vfsmount *);
-static void udf_error(struct super_block *sb, const char *function,
-		      const char *fmt, ...);
 
 struct logicalVolIntegrityDescImpUse *udf_sb_lvidiu(struct udf_sb_info *sbi)
 {
@@ -2098,8 +2096,8 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
 	return -EINVAL;
 }
 
-static void udf_error(struct super_block *sb, const char *function,
-		      const char *fmt, ...)
+void udf_error(struct super_block *sb, const char *function,
+	       const char *fmt, ...)
 {
 	va_list args;
 

fs/udf/udfdecl.h

@@ -29,6 +29,13 @@ do { \
 #define udf_debug(f, a...) /**/
 #endif
 
+__attribute__((format(printf, 3, 4)))
+extern void udf_warning(struct super_block *, const char *, const char *, ...);
+
+__attribute__((format(printf, 3, 4)))
+extern void udf_error(struct super_block *sb, const char *function,
+		      const char *fmt, ...);
+
 #define udf_info(f, a...) \
 	printk(KERN_INFO "UDF-fs INFO " f, ##a);
 
@@ -110,7 +117,6 @@ struct extent_position {
 };
 
 /* super.c */
-extern void udf_warning(struct super_block *, const char *, const char *, ...);
 static inline void udf_updated_lvid(struct super_block *sb)
 {
 	struct buffer_head *bh = UDF_SB(sb)->s_lvid_bh;