btrfs: add varargs to btrfs_error

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1a649dc47f78e8a8796a5bbb81225b2f0692cbcc..e9929828fc42f99eccf8d8c1da7c5732095a86b3 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2763,8 +2763,9 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 /* super.c */
 int btrfs_parse_options(struct btrfs_root *root, char *options);
 int btrfs_sync_fs(struct super_block *sb, int wait);
+void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...);
 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
-                    unsigned int line, int errno);
+                    unsigned int line, int errno, const char *fmt, ...);
 
 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root, const char *function,
@@ -2779,7 +2780,14 @@ do {                                                             \
 #define btrfs_std_error(fs_info, errno)                                \
 do {                                                           \
        if ((errno))                                            \
-               __btrfs_std_error((fs_info), __func__, __LINE__, (errno));\
+               __btrfs_std_error((fs_info), __func__,          \
+                                  __LINE__, (errno), NULL);    \
+} while (0)
+
+#define btrfs_error(fs_info, errno, fmt, args...)              \
+do {                                                           \
+       __btrfs_std_error((fs_info), __func__, __LINE__,        \
+                         (errno), fmt, ##args);                \
 } while (0)
 
 /* acl.c */

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a7d68c385b3db8523600ee73b0d85132db65f360..c63f35098f28078f801e9e7c75a1a8918b2df208 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -127,25 +127,74 @@ static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
  * invokes the approciate error response.
  */
 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
-                    unsigned int line, int errno)
+                      unsigned int line, int errno, const char *fmt, ...)
 {
        struct super_block *sb = fs_info->sb;
        char nbuf[16];
        const char *errstr;
+       va_list args;
+       va_start(args, fmt);
 
        /*
         * Special case: if the error is EROFS, and we're already
         * under MS_RDONLY, then it is safe here.
         */
        if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
-               return;
+               return;
+
+       errstr = btrfs_decode_error(fs_info, errno, nbuf);
+       if (fmt) {
+               struct va_format vaf = {
+                       .fmt = fmt,
+                       .va = &args,
+               };
 
-       errstr = btrfs_decode_error(fs_info, errno, nbuf);
-       printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
-               sb->s_id, function, line, errstr);
-       save_error_info(fs_info);
+               printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n",
+                       sb->s_id, function, line, errstr, &vaf);
+       } else {
+               printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
+                       sb->s_id, function, line, errstr);
+       }
 
-       btrfs_handle_error(fs_info);
+       /* Don't go through full error handling during mount */
+       if (sb->s_flags & MS_BORN) {
+               save_error_info(fs_info);
+               btrfs_handle_error(fs_info);
+       }
+       va_end(args);
+}
+
+const char *logtypes[] = {
+       "emergency",
+       "alert",
+       "critical",
+       "error",
+       "warning",
+       "notice",
+       "info",
+       "debug",
+};
+
+void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
+{
+       struct super_block *sb = fs_info->sb;
+       char lvl[4];
+       struct va_format vaf;
+       va_list args;
+       const char *type = logtypes[4];
+
+       va_start(args, fmt);
+
+       if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') {
+               strncpy(lvl, fmt, 3);
+               fmt += 3;
+               type = logtypes[fmt[1] - '0'];
+       } else
+               *lvl = '\0';
+
+       vaf.fmt = fmt;
+       vaf.va = &args;
+       printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf);
 }
 
 /*