btrfs: Convert fs_info->free_chunk_space to atomic64_t
The ->free_chunk_space variable is used to track the unallocated space
and access to it is protected by a spinlock, which is not used for
anything else. Make the code a bit self-explanatory by switching the
variable to an atomic64_t type and kill the spinlock.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ not a performance critical code, use of atomic type is ok ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 017b67d..e37f959 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2417,9 +2417,7 @@
fs_info->fs_devices->total_devices++;
fs_info->fs_devices->total_rw_bytes += device->total_bytes;
- spin_lock(&fs_info->free_chunk_lock);
- fs_info->free_chunk_space += device->total_bytes;
- spin_unlock(&fs_info->free_chunk_lock);
+ atomic64_add(device->total_bytes, &fs_info->free_chunk_space);
if (!blk_queue_nonrot(q))
fs_info->fs_devices->rotating = 1;
@@ -2874,9 +2872,7 @@
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_bytes_used(device,
device->bytes_used - dev_extent_len);
- spin_lock(&fs_info->free_chunk_lock);
- fs_info->free_chunk_space += dev_extent_len;
- spin_unlock(&fs_info->free_chunk_lock);
+ atomic64_add(dev_extent_len, &fs_info->free_chunk_space);
btrfs_clear_space_info_full(fs_info);
mutex_unlock(&fs_info->chunk_mutex);
}
@@ -4409,9 +4405,7 @@
btrfs_device_set_total_bytes(device, new_size);
if (device->writeable) {
device->fs_devices->total_rw_bytes -= diff;
- spin_lock(&fs_info->free_chunk_lock);
- fs_info->free_chunk_space -= diff;
- spin_unlock(&fs_info->free_chunk_lock);
+ atomic64_sub(diff, &fs_info->free_chunk_space);
}
mutex_unlock(&fs_info->chunk_mutex);
@@ -4535,9 +4529,7 @@
btrfs_device_set_total_bytes(device, old_size);
if (device->writeable)
device->fs_devices->total_rw_bytes += diff;
- spin_lock(&fs_info->free_chunk_lock);
- fs_info->free_chunk_space += diff;
- spin_unlock(&fs_info->free_chunk_lock);
+ atomic64_add(diff, &fs_info->free_chunk_space);
mutex_unlock(&fs_info->chunk_mutex);
}
return ret;
@@ -4882,9 +4874,7 @@
btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
}
- spin_lock(&info->free_chunk_lock);
- info->free_chunk_space -= (stripe_size * map->num_stripes);
- spin_unlock(&info->free_chunk_lock);
+ atomic64_sub(stripe_size * map->num_stripes, &info->free_chunk_space);
free_extent_map(em);
check_raid56_incompat_flag(info, type);
@@ -6684,10 +6674,8 @@
device->in_fs_metadata = 1;
if (device->writeable && !device->is_tgtdev_for_dev_replace) {
device->fs_devices->total_rw_bytes += device->total_bytes;
- spin_lock(&fs_info->free_chunk_lock);
- fs_info->free_chunk_space += device->total_bytes -
- device->bytes_used;
- spin_unlock(&fs_info->free_chunk_lock);
+ atomic64_add(device->total_bytes - device->bytes_used,
+ &fs_info->free_chunk_space);
}
ret = 0;
return ret;