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Commit de98ced9 authored by Miao Xie's avatar Miao Xie Committed by Josef Bacik
Browse files

Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits 



There is no lock to protect
  fs_info->avail_{data, metadata, system}_alloc_bits,
it may introduce some problem, such as the wrong profile
information, so we add a seqlock to protect them.

Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent df0af1a5

fs/btrfs/ctree.h

+2 −0
Original line number Diff line number Diff line
@@ -1483,6 +1483,8 @@ struct btrfs_fs_info { 
	struct rb_root defrag_inodes;

	atomic_t defrag_running;



	/* Used to protect avail_{data, metadata, system}_alloc_bits */

	seqlock_t profiles_lock;

	/*

	 * these three are in extended format (availability of single

	 * chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other

fs/btrfs/disk-io.c

+1 −0
Original line number Diff line number Diff line
@@ -2040,6 +2040,7 @@ int open_ctree(struct super_block *sb, 
	spin_lock_init(&fs_info->tree_mod_seq_lock);

	rwlock_init(&fs_info->tree_mod_log_lock);

	mutex_init(&fs_info->reloc_mutex);

	seqlock_init(&fs_info->profiles_lock);



	init_completion(&fs_info->kobj_unregister);

	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);

fs/btrfs/extent-tree.c

+16 −6
Original line number Diff line number Diff line
@@ -3227,12 +3227,14 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) 
	u64 extra_flags = chunk_to_extended(flags) &

				BTRFS_EXTENDED_PROFILE_MASK;



	write_seqlock(&fs_info->profiles_lock);

	if (flags & BTRFS_BLOCK_GROUP_DATA)

		fs_info->avail_data_alloc_bits |= extra_flags;

	if (flags & BTRFS_BLOCK_GROUP_METADATA)

		fs_info->avail_metadata_alloc_bits |= extra_flags;

	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)

		fs_info->avail_system_alloc_bits |= extra_flags;

	write_sequnlock(&fs_info->profiles_lock);

}



/*
@@ -3324,12 +3326,18 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) 


static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)

{

	unsigned seq;



	do {

		seq = read_seqbegin(&root->fs_info->profiles_lock);



		if (flags & BTRFS_BLOCK_GROUP_DATA)

			flags |= root->fs_info->avail_data_alloc_bits;

		else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)

			flags |= root->fs_info->avail_system_alloc_bits;

		else if (flags & BTRFS_BLOCK_GROUP_METADATA)

			flags |= root->fs_info->avail_metadata_alloc_bits;

	} while (read_seqretry(&root->fs_info->profiles_lock, seq));



	return btrfs_reduce_alloc_profile(root, flags);

}
@@ -7967,12 +7975,14 @@ static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) 
	u64 extra_flags = chunk_to_extended(flags) &

				BTRFS_EXTENDED_PROFILE_MASK;



	write_seqlock(&fs_info->profiles_lock);

	if (flags & BTRFS_BLOCK_GROUP_DATA)

		fs_info->avail_data_alloc_bits &= ~extra_flags;

	if (flags & BTRFS_BLOCK_GROUP_METADATA)

		fs_info->avail_metadata_alloc_bits &= ~extra_flags;

	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)

		fs_info->avail_system_alloc_bits &= ~extra_flags;

	write_sequnlock(&fs_info->profiles_lock);

}



int btrfs_remove_block_group(struct btrfs_trans_handle *trans,

fs/btrfs/volumes.c

+30 −26
Original line number Diff line number Diff line
@@ -1430,14 +1430,19 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 
	u64 devid;

	u64 num_devices;

	u8 *dev_uuid;

	unsigned seq;

	int ret = 0;

	bool clear_super = false;



	mutex_lock(&uuid_mutex);



	do {

		seq = read_seqbegin(&root->fs_info->profiles_lock);



		all_avail = root->fs_info->avail_data_alloc_bits |

			    root->fs_info->avail_system_alloc_bits |

			    root->fs_info->avail_metadata_alloc_bits;

	} while (read_seqretry(&root->fs_info->profiles_lock, seq));



	num_devices = root->fs_info->fs_devices->num_devices;

	btrfs_dev_replace_lock(&root->fs_info->dev_replace);
@@ -3043,6 +3048,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl, 
	int mixed = 0;

	int ret;

	u64 num_devices;

	unsigned seq;



	if (btrfs_fs_closing(fs_info) ||

	    atomic_read(&fs_info->balance_pause_req) ||
@@ -3126,6 +3132,9 @@ int btrfs_balance(struct btrfs_balance_control *bctl, 
	/* allow to reduce meta or sys integrity only if force set */

	allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |

			BTRFS_BLOCK_GROUP_RAID10;

	do {

		seq = read_seqbegin(&fs_info->profiles_lock);



		if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&

		     (fs_info->avail_system_alloc_bits & allowed) &&

		     !(bctl->sys.target & allowed)) ||
@@ -3142,6 +3151,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl, 
				goto out;

			}

		}

	} while (read_seqretry(&fs_info->profiles_lock, seq));



	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {

		int num_tolerated_disk_barrier_failures;
@@ -3980,10 +3990,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans, 
	if (ret)

		return ret;



	alloc_profile = BTRFS_BLOCK_GROUP_METADATA |

				fs_info->avail_metadata_alloc_bits;

	alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);



	alloc_profile = btrfs_get_alloc_profile(extent_root, 0);

	ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,

				  &stripe_size, chunk_offset, alloc_profile);

	if (ret)
@@ -3991,10 +3998,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans, 


	sys_chunk_offset = chunk_offset + chunk_size;



	alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |

				fs_info->avail_system_alloc_bits;

	alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);



	alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);

	ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,

				  &sys_chunk_size, &sys_stripe_size,

				  sys_chunk_offset, alloc_profile);