1 files changed, 171 insertions, 19 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3ce97b217cbe..9db64165123a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -76,6 +76,9 @@ static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
         case -EROFS:
                 errstr = "Readonly filesystem";
                 break;
+        case -EEXIST:
+                errstr = "Object already exists";
+                break;
         default:
                 if (nbuf) {
                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
@@ -116,6 +119,8 @@ static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
                 sb->s_flags |= MS_RDONLY;
                 printk(KERN_INFO "btrfs is forced readonly\n");
+                __btrfs_scrub_cancel(fs_info);
+//              WARN_ON(1);
         }
 }
 
@@ -124,25 +129,132 @@ 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;
+
+        errstr = btrfs_decode_error(fs_info, errno, nbuf);
+        if (fmt) {
+                struct va_format vaf = {
+                        .fmt = fmt,
+                        .va = &args,
+                };
+
+                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);
+        }
+
+        /* 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);
+}
+
+/*
+ * We only mark the transaction aborted and then set the file system read-only.
+ * This will prevent new transactions from starting or trying to join this
+ * one.
+ *
+ * This means that error recovery at the call site is limited to freeing
+ * any local memory allocations and passing the error code up without
+ * further cleanup. The transaction should complete as it normally would
+ * in the call path but will return -EIO.
+ *
+ * We'll complete the cleanup in btrfs_end_transaction and
+ * btrfs_commit_transaction.
+ */
+void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root, const char *function,
+                               unsigned int line, int errno)
+{
+        WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted");
+        trans->aborted = errno;
+        /* Nothing used. The other threads that have joined this
+         * transaction may be able to continue. */
+        if (!trans->blocks_used) {
+                btrfs_printk(root->fs_info, "Aborting unused transaction.\n");
                 return;
+        }
+        trans->transaction->aborted = errno;
+        __btrfs_std_error(root->fs_info, function, line, errno, NULL);
+}
+/*
+ * __btrfs_panic decodes unexpected, fatal errors from the caller,
+ * issues an alert, and either panics or BUGs, depending on mount options.
+ */
+void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
+                   unsigned int line, int errno, const char *fmt, ...)
+{
+        char nbuf[16];
+        char *s_id = "<unknown>";
+        const char *errstr;
+        struct va_format vaf = { .fmt = fmt };
+        va_list 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);
+        if (fs_info)
+                s_id = fs_info->sb->s_id;
+
+        va_start(args, fmt);
+        vaf.va = &args;
 
-        btrfs_handle_error(fs_info);
+        errstr = btrfs_decode_error(fs_info, errno, nbuf);
+        if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)
+                panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
+                        s_id, function, line, &vaf, errstr);
+
+        printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
+               s_id, function, line, &vaf, errstr);
+        va_end(args);
+        /* Caller calls BUG() */
 }
 
 static void btrfs_put_super(struct super_block *sb)
@@ -166,7 +278,7 @@ enum {
         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
         Opt_check_integrity, Opt_check_integrity_including_extent_data,
-        Opt_check_integrity_print_mask,
+        Opt_check_integrity_print_mask, Opt_fatal_errors,
         Opt_err,
 };
 
@@ -206,12 +318,14 @@ static match_table_t tokens = {
         {Opt_check_integrity, "check_int"},
         {Opt_check_integrity_including_extent_data, "check_int_data"},
         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
+        {Opt_fatal_errors, "fatal_errors=%s"},
         {Opt_err, NULL},
 };
 
 /*
  * Regular mount options parser.  Everything that is needed only when
  * reading in a new superblock is parsed here.
+ * XXX JDM: This needs to be cleaned up for remount.
  */
 int btrfs_parse_options(struct btrfs_root *root, char *options)
 {
@@ -438,6 +552,18 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         ret = -EINVAL;
                         goto out;
 #endif
+                case Opt_fatal_errors:
+                        if (strcmp(args[0].from, "panic") == 0)
+                                btrfs_set_opt(info->mount_opt,
+                                              PANIC_ON_FATAL_ERROR);
+                        else if (strcmp(args[0].from, "bug") == 0)
+                                btrfs_clear_opt(info->mount_opt,
+                                              PANIC_ON_FATAL_ERROR);
+                        else {
+                                ret = -EINVAL;
+                                goto out;
+                        }
+                        break;
                 case Opt_err:
                         printk(KERN_INFO "btrfs: unrecognized mount option "
                                "'%s'\n", p);
@@ -766,6 +892,8 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
                 seq_puts(seq, ",inode_cache");
         if (btrfs_test_opt(root, SKIP_BALANCE))
                 seq_puts(seq, ",skip_balance");
+        if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
+                seq_puts(seq, ",fatal_errors=panic");
         return 0;
 }
 
@@ -999,11 +1127,20 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 {
         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
         struct btrfs_root *root = fs_info->tree_root;
+        unsigned old_flags = sb->s_flags;
+        unsigned long old_opts = fs_info->mount_opt;
+        unsigned long old_compress_type = fs_info->compress_type;
+        u64 old_max_inline = fs_info->max_inline;
+        u64 old_alloc_start = fs_info->alloc_start;
+        int old_thread_pool_size = fs_info->thread_pool_size;
+        unsigned int old_metadata_ratio = fs_info->metadata_ratio;
         int ret;
 
         ret = btrfs_parse_options(root, data);
-        if (ret)
-                return -EINVAL;
+        if (ret) {
+                ret = -EINVAL;
+                goto restore;
+        }
 
         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
                 return 0;
@@ -1011,26 +1148,44 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
         if (*flags & MS_RDONLY) {
                 sb->s_flags |= MS_RDONLY;
 
-                ret =  btrfs_commit_super(root);
-                WARN_ON(ret);
+                ret = btrfs_commit_super(root);
+                if (ret)
+                        goto restore;
         } else {
                 if (fs_info->fs_devices->rw_devices == 0)
-                        return -EACCES;
+                        ret = -EACCES;
+                        goto restore;
 
                 if (btrfs_super_log_root(fs_info->super_copy) != 0)
-                        return -EINVAL;
+                        ret = -EINVAL;
+                        goto restore;
 
                 ret = btrfs_cleanup_fs_roots(fs_info);
-                WARN_ON(ret);
+                if (ret)
+                        goto restore;
 
                 /* recover relocation */
                 ret = btrfs_recover_relocation(root);
-                WARN_ON(ret);
+                if (ret)
+                        goto restore;
 
                 sb->s_flags &= ~MS_RDONLY;
         }
 
         return 0;
+
+restore:
+        /* We've hit an error - don't reset MS_RDONLY */
+        if (sb->s_flags & MS_RDONLY)
+                old_flags |= MS_RDONLY;
+        sb->s_flags = old_flags;
+        fs_info->mount_opt = old_opts;
+        fs_info->compress_type = old_compress_type;
+        fs_info->max_inline = old_max_inline;
+        fs_info->alloc_start = old_alloc_start;
+        fs_info->thread_pool_size = old_thread_pool_size;
+        fs_info->metadata_ratio = old_metadata_ratio;
+        return ret;
 }
 
 /* Used to sort the devices by max_avail(descending sort) */
@@ -1360,9 +1515,7 @@ static int __init init_btrfs_fs(void)
         if (err)
                 return err;
 
-        err = btrfs_init_compress();
-        if (err)
-                goto free_sysfs;
+        btrfs_init_compress();
 
         err = btrfs_init_cachep();
         if (err)
@@ -1403,7 +1556,6 @@ free_cachep:
         btrfs_destroy_cachep();
 free_compress:
         btrfs_exit_compress();
-free_sysfs:
         btrfs_exit_sysfs();
         return err;
 }