btrfs: factor out gather_device_info()

Factor out gather_device_info() from __btrfs_alloc_chunk(). This
function iterates over devices list and gather information about
devices. This commit also introduces "max_avail" and
"dev_extent_min" to fold the same calculation to one variable.
This commit has no functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Naohiro Aota 2020-02-25 12:56:12 +09:00 committed by David Sterba
parent 27c314d5ca
commit 560156cb25
1 changed files with 83 additions and 70 deletions

View File

@ -4865,22 +4865,97 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
}
}
static int gather_device_info(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = fs_devices->fs_info;
struct btrfs_device *device;
u64 total_avail;
u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes;
u64 dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
int ret;
int ndevs = 0;
u64 max_avail;
u64 dev_offset;
/*
* in the first pass through the devices list, we gather information
* about the available holes on each device.
*/
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
WARN(1, KERN_ERR
"BTRFS: read-only device in alloc_list\n");
continue;
}
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
continue;
if (device->total_bytes > device->bytes_used)
total_avail = device->total_bytes - device->bytes_used;
else
total_avail = 0;
/* If there is no space on this device, skip it. */
if (total_avail == 0)
continue;
ret = find_free_dev_extent(device, dev_extent_want, &dev_offset,
&max_avail);
if (ret && ret != -ENOSPC)
return ret;
if (ret == 0)
max_avail = dev_extent_want;
if (max_avail < dev_extent_min) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info,
"%s: devid %llu has no free space, have=%llu want=%llu",
__func__, device->devid, max_avail,
dev_extent_min);
continue;
}
if (ndevs == fs_devices->rw_devices) {
WARN(1, "%s: found more than %llu devices\n",
__func__, fs_devices->rw_devices);
break;
}
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
}
ctl->ndevs = ndevs;
/*
* now sort the devices by hole size / available space
*/
sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
btrfs_cmp_device_info, NULL);
return 0;
}
static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
u64 start, u64 type)
{
struct btrfs_fs_info *info = trans->fs_info;
struct btrfs_fs_devices *fs_devices = info->fs_devices;
struct btrfs_device *device;
struct map_lookup *map = NULL;
struct extent_map_tree *em_tree;
struct extent_map *em;
struct btrfs_device_info *devices_info = NULL;
struct alloc_chunk_ctl ctl;
u64 total_avail;
int data_stripes; /* number of stripes that count for
block group size */
/* Number of stripes that count for block group size */
int data_stripes;
int ret;
int ndevs;
int i;
int j;
@ -4910,71 +4985,9 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
if (!devices_info)
return -ENOMEM;
/*
* in the first pass through the devices list, we gather information
* about the available holes on each device.
*/
ndevs = 0;
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
u64 max_avail;
u64 dev_offset;
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
WARN(1, KERN_ERR
"BTRFS: read-only device in alloc_list\n");
continue;
}
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
continue;
if (device->total_bytes > device->bytes_used)
total_avail = device->total_bytes - device->bytes_used;
else
total_avail = 0;
/* If there is no space on this device, skip it. */
if (total_avail == 0)
continue;
ret = find_free_dev_extent(
device, ctl.max_stripe_size * ctl.dev_stripes,
&dev_offset, &max_avail);
if (ret && ret != -ENOSPC)
goto error;
if (ret == 0)
max_avail = ctl.max_stripe_size * ctl.dev_stripes;
if (max_avail < BTRFS_STRIPE_LEN * ctl.dev_stripes) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info,
"%s: devid %llu has no free space, have=%llu want=%u",
__func__, device->devid, max_avail,
BTRFS_STRIPE_LEN * ctl.dev_stripes);
continue;
}
if (ndevs == fs_devices->rw_devices) {
WARN(1, "%s: found more than %llu devices\n",
__func__, fs_devices->rw_devices);
break;
}
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
}
ctl.ndevs = ndevs;
/*
* now sort the devices by hole size / available space
*/
sort(devices_info, ctl.ndevs, sizeof(struct btrfs_device_info),
btrfs_cmp_device_info, NULL);
ret = gather_device_info(fs_devices, &ctl, devices_info);
if (ret < 0)
goto error;
/*
* Round down to number of usable stripes, devs_increment can be any