[RFC PATCH 05/12] btrfs-progs: load and check zone information

From: Naohiro Aota
Date: Thu Aug 09 2018 - 14:11:24 EST


This patch checks if a device added to btrfs is a zoned block device. If it
is, load zones information and the zone size for the device.

For a btrfs volume composed of multiple zoned block devices, all devices
must have the same zone size.

Signed-off-by: Naohiro Aota <naota@xxxxxxxxx>
---
utils.c | 10 ++++++++++
volumes.c | 18 ++++++++++++++++++
volumes.h | 3 +++
3 files changed, 31 insertions(+)

diff --git a/utils.c b/utils.c
index 71fc044a..a2172a82 100644
--- a/utils.c
+++ b/utils.c
@@ -250,6 +250,16 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
goto out;
}

+ ret = btrfs_get_zone_info(fd, path, fs_info->fs_devices->hmzoned,
+ &device->zinfo);
+ if (ret)
+ goto out;
+ if (device->zinfo.zone_size != fs_info->fs_devices->zone_size) {
+ error("Device zone size differ\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
disk_super = (struct btrfs_super_block *)buf;
dev_item = &disk_super->dev_item;

diff --git a/volumes.c b/volumes.c
index d81b348e..2ec27cd7 100644
--- a/volumes.c
+++ b/volumes.c
@@ -160,6 +160,8 @@ static int device_list_add(const char *path,
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices;
u64 found_transid = btrfs_super_generation(disk_super);
+ int hmzoned = btrfs_super_incompat_flags(disk_super) &
+ BTRFS_FEATURE_INCOMPAT_HMZONED;

fs_devices = find_fsid(disk_super->fsid);
if (!fs_devices) {
@@ -237,6 +239,8 @@ static int device_list_add(const char *path,
if (fs_devices->lowest_devid > devid) {
fs_devices->lowest_devid = devid;
}
+ if (hmzoned)
+ fs_devices->hmzoned = 1;
*fs_devices_ret = fs_devices;
return 0;
}
@@ -307,6 +311,8 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
struct btrfs_device *device;
int ret;

+ fs_devices->zone_size = 0;
+
list_for_each_entry(device, &fs_devices->devices, dev_list) {
if (!device->name) {
printk("no name for device %llu, skip it now\n", device->devid);
@@ -330,6 +336,18 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
device->fd = fd;
if (flags & O_RDWR)
device->writeable = 1;
+
+ ret = btrfs_get_zone_info(fd, device->name, fs_devices->hmzoned,
+ &device->zinfo);
+ if (ret != 0)
+ goto fail;
+ if (!fs_devices->zone_size) {
+ fs_devices->zone_size = device->zinfo.zone_size;
+ } else if (device->zinfo.zone_size != fs_devices->zone_size) {
+ fprintf(stderr, "Device zone size differ\n");
+ ret = -EINVAL;
+ goto fail;
+ }
}
return 0;
fail:
diff --git a/volumes.h b/volumes.h
index bad688e5..36a6f44b 100644
--- a/volumes.h
+++ b/volumes.h
@@ -111,6 +111,9 @@ struct btrfs_fs_devices {

int seeding;
struct btrfs_fs_devices *seed;
+
+ u64 zone_size;
+ unsigned int hmzoned:1;
};

struct btrfs_bio_stripe {
--
2.18.0