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: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1ce581d..8c9ea4c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1430,14 +1430,19 @@
u64 devid;
u64 num_devices;
u8 *dev_uuid;
+ unsigned seq;
int ret = 0;
bool clear_super = false;
mutex_lock(&uuid_mutex);
- all_avail = root->fs_info->avail_data_alloc_bits |
- root->fs_info->avail_system_alloc_bits |
- root->fs_info->avail_metadata_alloc_bits;
+ 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 mixed = 0;
int ret;
u64 num_devices;
+ unsigned seq;
if (btrfs_fs_closing(fs_info) ||
atomic_read(&fs_info->balance_pause_req) ||
@@ -3126,22 +3132,26 @@
/* allow to reduce meta or sys integrity only if force set */
allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10;
- if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
- (fs_info->avail_system_alloc_bits & allowed) &&
- !(bctl->sys.target & allowed)) ||
- ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
- (fs_info->avail_metadata_alloc_bits & allowed) &&
- !(bctl->meta.target & allowed))) {
- if (bctl->flags & BTRFS_BALANCE_FORCE) {
- printk(KERN_INFO "btrfs: force reducing metadata "
- "integrity\n");
- } else {
- printk(KERN_ERR "btrfs: balance will reduce metadata "
- "integrity, use force if you want this\n");
- ret = -EINVAL;
- goto out;
+ 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)) ||
+ ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_metadata_alloc_bits & allowed) &&
+ !(bctl->meta.target & allowed))) {
+ if (bctl->flags & BTRFS_BALANCE_FORCE) {
+ printk(KERN_INFO "btrfs: force reducing metadata "
+ "integrity\n");
+ } else {
+ printk(KERN_ERR "btrfs: balance will reduce metadata "
+ "integrity, use force if you want this\n");
+ ret = -EINVAL;
+ 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 @@
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 @@
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);