@@ -2552,6 +2552,14 @@ 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_std_error(struct btrfs_fs_info *fs_info, const char *function,
+ unsigned int line, int errno);
+
+#define btrfs_std_error(fs_info, errno) \
+do { \
+ if ((errno)) \
+ __btrfs_std_error((fs_info), __func__, __LINE__, (errno));\
+} while (0)
/* acl.c */
#ifdef CONFIG_BTRFS_FS_POSIX_ACL
@@ -54,6 +54,94 @@
static const struct super_operations btrfs_super_ops;
+static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
+ char nbuf[16])
+{
+ char *errstr = NULL;
+
+ switch (errno) {
+ case -EIO:
+ errstr = "IO failure";
+ break;
+ case -ENOMEM:
+ errstr = "Out of memory";
+ break;
+ case -EROFS:
+ errstr = "Readonly filesystem";
+ break;
+ default:
+ if (nbuf) {
+ if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
+ errstr = nbuf;
+ }
+ break;
+ }
+
+ return errstr;
+}
+
+static void __save_error_info(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_super_block *disk_super = &fs_info->super_copy;
+
+ fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
+ disk_super->flags |= cpu_to_le64(BTRFS_SUPER_FLAG_ERROR);
+
+ mutex_lock(&fs_info->trans_mutex);
+ memcpy(&fs_info->super_for_commit, disk_super,
+ sizeof(fs_info->super_for_commit));
+ mutex_unlock(&fs_info->trans_mutex);
+}
+
+/* NOTE:
+ * We move write_super stuff at umount in order to avoid deadlock
+ * for umount hold all lock.
+ */
+static void save_error_info(struct btrfs_fs_info *fs_info)
+{
+ __save_error_info(fs_info);
+}
+
+/* btrfs handle error by forcing the filesystem readonly */
+static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
+{
+ struct super_block *sb = fs_info->sb;
+
+ if (sb->s_flags & MS_RDONLY)
+ return;
+
+ if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ sb->s_flags |= MS_RDONLY;
+ printk(KERN_INFO "btrfs is forced readonly\n");
+ }
+}
+
+/*
+ * __btrfs_std_error decodes expected errors from the caller and
+ * invokes the approciate error response.
+ */
+void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
+ unsigned int line, int errno)
+{
+ struct super_block *sb = fs_info->sb;
+ char nbuf[16];
+ const char *errstr;
+
+ /*
+ * 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;
+
+ 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);
+
+ btrfs_handle_error(fs_info);
+}
+
static void btrfs_put_super(struct super_block *sb)
{
struct btrfs_root *root = btrfs_sb(sb);