X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fsuper.c;h=6f49b2872a6454330bac0ef912be3d0152e2ef4f;hb=a53f4f8e9c8ebe6c9ee3b34c368913aae9876e22;hp=a2b97ef10317081aebaa09aedeaddf4dec71a492;hpb=14d4cc08832efb724e58944ba2ac22e2ca3143dc;p=cascardo%2Flinux.git

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a2b97ef10317..6f49b2872a64 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -262,7 +262,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 	trans->aborted = errno;
 	/* Nothing used. The other threads that have joined this
 	 * transaction may be able to continue. */
-	if (!trans->blocks_used) {
+	if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
 		const char *errstr;
 
 		errstr = btrfs_decode_error(errno);
@@ -642,11 +642,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 					     "disabling disk space caching");
 			break;
 		case Opt_inode_cache:
-			btrfs_set_and_info(root, CHANGE_INODE_CACHE,
+			btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
 					   "enabling inode map caching");
 			break;
 		case Opt_noinode_cache:
-			btrfs_clear_and_info(root, CHANGE_INODE_CACHE,
+			btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
 					     "disabling inode map caching");
 			break;
 		case Opt_clear_cache:
@@ -993,9 +993,27 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 	trans = btrfs_attach_transaction_barrier(root);
 	if (IS_ERR(trans)) {
 		/* no transaction, don't bother */
-		if (PTR_ERR(trans) == -ENOENT)
-			return 0;
-		return PTR_ERR(trans);
+		if (PTR_ERR(trans) == -ENOENT) {
+			/*
+			 * Exit unless we have some pending changes
+			 * that need to go through commit
+			 */
+			if (fs_info->pending_changes == 0)
+				return 0;
+			/*
+			 * A non-blocking test if the fs is frozen. We must not
+			 * start a new transaction here otherwise a deadlock
+			 * happens. The pending operations are delayed to the
+			 * next commit after thawing.
+			 */
+			if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
+				__sb_end_write(sb, SB_FREEZE_WRITE);
+			else
+				return 0;
+			trans = btrfs_start_transaction(root, 0);
+		}
+		if (IS_ERR(trans))
+			return PTR_ERR(trans);
 	}
 	return btrfs_commit_transaction(trans, root);
 }
@@ -1644,8 +1662,20 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
 	int i = 0, nr_devices;
 	int ret;
 
+	/*
+	 * We aren't under the device list lock, so this is racey-ish, but good
+	 * enough for our purposes.
+	 */
 	nr_devices = fs_info->fs_devices->open_devices;
-	BUG_ON(!nr_devices);
+	if (!nr_devices) {
+		smp_mb();
+		nr_devices = fs_info->fs_devices->open_devices;
+		ASSERT(nr_devices);
+		if (!nr_devices) {
+			*free_bytes = 0;
+			return 0;
+		}
+	}
 
 	devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
 			       GFP_NOFS);
@@ -1670,11 +1700,17 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
 	else
 		min_stripe_size = BTRFS_STRIPE_LEN;
 
-	list_for_each_entry(device, &fs_devices->devices, dev_list) {
+	if (fs_info->alloc_start)
+		mutex_lock(&fs_devices->device_list_mutex);
+	rcu_read_lock();
+	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
 		if (!device->in_fs_metadata || !device->bdev ||
 		    device->is_tgtdev_for_dev_replace)
 			continue;
 
+		if (i >= nr_devices)
+			break;
+
 		avail_space = device->total_bytes - device->bytes_used;
 
 		/* align with stripe_len */
@@ -1689,24 +1725,32 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
 		skip_space = 1024 * 1024;
 
 		/* user can set the offset in fs_info->alloc_start. */
-		if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
-		    device->total_bytes)
+		if (fs_info->alloc_start &&
+		    fs_info->alloc_start + BTRFS_STRIPE_LEN <=
+		    device->total_bytes) {
+			rcu_read_unlock();
 			skip_space = max(fs_info->alloc_start, skip_space);
 
-		/*
-		 * btrfs can not use the free space in [0, skip_space - 1],
-		 * we must subtract it from the total. In order to implement
-		 * it, we account the used space in this range first.
-		 */
-		ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
-						     &used_space);
-		if (ret) {
-			kfree(devices_info);
-			return ret;
-		}
+			/*
+			 * btrfs can not use the free space in
+			 * [0, skip_space - 1], we must subtract it from the
+			 * total. In order to implement it, we account the used
+			 * space in this range first.
+			 */
+			ret = btrfs_account_dev_extents_size(device, 0,
+							     skip_space - 1,
+							     &used_space);
+			if (ret) {
+				kfree(devices_info);
+				mutex_unlock(&fs_devices->device_list_mutex);
+				return ret;
+			}
+
+			rcu_read_lock();
 
-		/* calc the free space in [0, skip_space - 1] */
-		skip_space -= used_space;
+			/* calc the free space in [0, skip_space - 1] */
+			skip_space -= used_space;
+		}
 
 		/*
 		 * we can use the free space in [0, skip_space - 1], subtract
@@ -1725,6 +1769,9 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
 
 		i++;
 	}
+	rcu_read_unlock();
+	if (fs_info->alloc_start)
+		mutex_unlock(&fs_devices->device_list_mutex);
 
 	nr_devices = i;
 
@@ -1787,8 +1834,6 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	 * holding chunk_muext to avoid allocating new chunks, holding
 	 * device_list_mutex to avoid the device being removed
 	 */
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	mutex_lock(&fs_info->chunk_mutex);
 	rcu_read_lock();
 	list_for_each_entry_rcu(found, head, list) {
 		if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
@@ -1824,17 +1869,12 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bfree -= block_rsv->size >> bits;
 	spin_unlock(&block_rsv->lock);
 
-	buf->f_bavail = total_free_data;
+	buf->f_bavail = div_u64(total_free_data, factor);
 	ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
-	if (ret) {
-		mutex_unlock(&fs_info->chunk_mutex);
-		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+	if (ret)
 		return ret;
-	}
 	buf->f_bavail += div_u64(total_free_data, factor);
 	buf->f_bavail = buf->f_bavail >> bits;
-	mutex_unlock(&fs_info->chunk_mutex);
-	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 
 	buf->f_type = BTRFS_SUPER_MAGIC;
 	buf->f_bsize = dentry->d_sb->s_blocksize;
@@ -2151,6 +2191,7 @@ static void __exit exit_btrfs_fs(void)
 	extent_map_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
+	btrfs_end_io_wq_exit();
 	unregister_filesystem(&btrfs_fs_type);
 	btrfs_exit_sysfs();
 	btrfs_cleanup_fs_uuids();