6 files changed, 142 insertions, 19 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 50dcd0f..1630be8 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1468,6 +1468,8 @@ struct btrfs_fs_info {
 
 	/* next backup root to be overwritten */
 	int backup_root_index;
+
+	int num_tolerated_disk_barrier_failures;
 };
 
 /*
@@ -3361,6 +3363,9 @@ void btrfs_inherit_iflags(struct inode *inode, struct inode *dir);
 int btrfs_defrag_file(struct inode *inode, struct file *file,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_pages);
+void btrfs_get_block_group_info(struct list_head *groups_list,
+				struct btrfs_ioctl_space_info *space);
+
 /* file.c */
 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
 			   struct inode *inode);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c699955..8355236 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2505,6 +2505,8 @@ retry_root_backup:
 		printk(KERN_ERR "Failed to read block groups: %d\n", ret);
 		goto fail_block_groups;
 	}
+	fs_info->num_tolerated_disk_barrier_failures =
+		btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
 
 	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
 					       "btrfs-cleaner");
@@ -2888,12 +2890,10 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
 			printk_in_rcu("btrfs: disabling barriers on dev %s\n",
 				      rcu_str_deref(device->name));
 			device->nobarriers = 1;
-		}
-		if (!bio_flagged(bio, BIO_UPTODATE)) {
+		} else if (!bio_flagged(bio, BIO_UPTODATE)) {
 			ret = -EIO;
-			if (!bio_flagged(bio, BIO_EOPNOTSUPP))
-				btrfs_dev_stat_inc_and_print(device,
-					BTRFS_DEV_STAT_FLUSH_ERRS);
+			btrfs_dev_stat_inc_and_print(device,
+				BTRFS_DEV_STAT_FLUSH_ERRS);
 		}
 
 		/* drop the reference from the wait == 0 run */
@@ -2932,14 +2932,15 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 {
 	struct list_head *head;
 	struct btrfs_device *dev;
-	int errors = 0;
+	int errors_send = 0;
+	int errors_wait = 0;
 	int ret;
 
 	/* send down all the barriers */
 	head = &info->fs_devices->devices;
 	list_for_each_entry_rcu(dev, head, dev_list) {
 		if (!dev->bdev) {
-			errors++;
+			errors_send++;
 			continue;
 		}
 		if (!dev->in_fs_metadata || !dev->writeable)
@@ -2947,13 +2948,13 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 
 		ret = write_dev_flush(dev, 0);
 		if (ret)
-			errors++;
+			errors_send++;
 	}
 
 	/* wait for all the barriers */
 	list_for_each_entry_rcu(dev, head, dev_list) {
 		if (!dev->bdev) {
-			errors++;
+			errors_wait++;
 			continue;
 		}
 		if (!dev->in_fs_metadata || !dev->writeable)
@@ -2961,13 +2962,87 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 
 		ret = write_dev_flush(dev, 1);
 		if (ret)
-			errors++;
+			errors_wait++;
 	}
-	if (errors)
+	if (errors_send > info->num_tolerated_disk_barrier_failures ||
+	    errors_wait > info->num_tolerated_disk_barrier_failures)
 		return -EIO;
 	return 0;
 }
 
+int btrfs_calc_num_tolerated_disk_barrier_failures(
+	struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_ioctl_space_info space;
+	struct btrfs_space_info *sinfo;
+	u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
+		       BTRFS_BLOCK_GROUP_SYSTEM,
+		       BTRFS_BLOCK_GROUP_METADATA,
+		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
+	int num_types = 4;
+	int i;
+	int c;
+	int num_tolerated_disk_barrier_failures =
+		(int)fs_info->fs_devices->num_devices;
+
+	for (i = 0; i < num_types; i++) {
+		struct btrfs_space_info *tmp;
+
+		sinfo = NULL;
+		rcu_read_lock();
+		list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
+			if (tmp->flags == types[i]) {
+				sinfo = tmp;
+				break;
+			}
+		}
+		rcu_read_unlock();
+
+		if (!sinfo)
+			continue;
+
+		down_read(&sinfo->groups_sem);
+		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
+			if (!list_empty(&sinfo->block_groups[c])) {
+				u64 flags;
+
+				btrfs_get_block_group_info(
+					&sinfo->block_groups[c], &space);
+				if (space.total_bytes == 0 ||
+				    space.used_bytes == 0)
+					continue;
+				flags = space.flags;
+				/*
+				 * return
+				 * 0: if dup, single or RAID0 is configured for
+				 *    any of metadata, system or data, else
+				 * 1: if RAID5 is configured, or if RAID1 or
+				 *    RAID10 is configured and only two mirrors
+				 *    are used, else
+				 * 2: if RAID6 is configured, else
+				 * num_mirrors - 1: if RAID1 or RAID10 is
+				 *                  configured and more than
+				 *                  2 mirrors are used.
+				 */
+				if (num_tolerated_disk_barrier_failures > 0 &&
+				    ((flags & (BTRFS_BLOCK_GROUP_DUP |
+					       BTRFS_BLOCK_GROUP_RAID0)) ||
+				     ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
+				      == 0)))
+					num_tolerated_disk_barrier_failures = 0;
+				else if (num_tolerated_disk_barrier_failures > 1
+					 &&
+					 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+						   BTRFS_BLOCK_GROUP_RAID10)))
+					num_tolerated_disk_barrier_failures = 1;
+			}
+		}
+		up_read(&sinfo->groups_sem);
+	}
+
+	return num_tolerated_disk_barrier_failures;
+}
+
 int write_all_supers(struct btrfs_root *root, int max_mirrors)
 {
 	struct list_head *head;
@@ -2990,8 +3065,16 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
 	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 	head = &root->fs_info->fs_devices->devices;
 
-	if (do_barriers)
-		barrier_all_devices(root->fs_info);
+	if (do_barriers) {
+		ret = barrier_all_devices(root->fs_info);
+		if (ret) {
+			mutex_unlock(
+				&root->fs_info->fs_devices->device_list_mutex);
+			btrfs_error(root->fs_info, ret,
+				    "errors while submitting device barriers.");
+			return ret;
+		}
+	}
 
 	list_for_each_entry_rcu(dev, head, dev_list) {
 		if (!dev->bdev) {
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index c5b00a7..2025a91 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -95,6 +95,8 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     u64 objectid);
 int btree_lock_page_hook(struct page *page, void *data,
 				void (*flush_fn)(void *));
+int btrfs_calc_num_tolerated_disk_barrier_failures(
+	struct btrfs_fs_info *fs_info);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void btrfs_init_lockdep(void);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d6836af6..f5a2e6c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2875,8 +2875,8 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	return 0;
 }
 
-static void get_block_group_info(struct list_head *groups_list,
-				 struct btrfs_ioctl_space_info *space)
+void btrfs_get_block_group_info(struct list_head *groups_list,
+				struct btrfs_ioctl_space_info *space)
 {
 	struct btrfs_block_group_cache *block_group;
 
@@ -2984,8 +2984,8 @@ long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 		down_read(&info->groups_sem);
 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
 			if (!list_empty(&info->block_groups[c])) {
-				get_block_group_info(&info->block_groups[c],
-						     &space);
+				btrfs_get_block_group_info(
+					&info->block_groups[c], &space);
 				memcpy(dest, &space, sizeof(space));
 				dest++;
 				space_args.total_spaces++;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 47911fd..67eab2d 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2425,9 +2425,12 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	 * in and cause problems either.
 	 */
 	btrfs_scrub_pause_super(root);
-	write_ctree_super(trans, root->fs_info->tree_root, 1);
+	ret = write_ctree_super(trans, root->fs_info->tree_root, 1);
 	btrfs_scrub_continue_super(root);
-	ret = 0;
+	if (ret) {
+		btrfs_abort_transaction(trans, root, ret);
+		goto out_wake_log_root;
+	}
 
 	mutex_lock(&root->log_mutex);
 	if (root->last_log_commit < log_transid)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dfe5e3a..029b903 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1475,6 +1475,9 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 		free_fs_devices(cur_devices);
 	}
 
+	root->fs_info->num_tolerated_disk_barrier_failures =
+		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
+
 	/*
 	 * at this point, the device is zero sized.  We want to
 	 * remove it from the devices list and zero out the old super
@@ -1799,6 +1802,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	btrfs_clear_space_info_full(root->fs_info);
 
 	unlock_chunks(root);
+	root->fs_info->num_tolerated_disk_barrier_failures =
+		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
 	ret = btrfs_commit_transaction(trans, root);
 
 	if (seeding_dev) {
@@ -2809,6 +2814,26 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		}
 	}
 
+	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		int num_tolerated_disk_barrier_failures;
+		u64 target = bctl->sys.target;
+
+		num_tolerated_disk_barrier_failures =
+			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
+		if (num_tolerated_disk_barrier_failures > 0 &&
+		    (target &
+		     (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
+		      BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
+			num_tolerated_disk_barrier_failures = 0;
+		else if (num_tolerated_disk_barrier_failures > 1 &&
+			 (target &
+			  (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
+			num_tolerated_disk_barrier_failures = 1;
+
+		fs_info->num_tolerated_disk_barrier_failures =
+			num_tolerated_disk_barrier_failures;
+	}
+
 	ret = insert_balance_item(fs_info->tree_root, bctl);
 	if (ret && ret != -EEXIST)
 		goto out;
@@ -2841,6 +2866,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		__cancel_balance(fs_info);
 	}
 
+	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		fs_info->num_tolerated_disk_barrier_failures =
+			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
+	}
+
 	wake_up(&fs_info->balance_wait_q);
 
 	return ret;