This is a preparation patch to implement zone emulation on a regular
device.
To emulate a zoned filesystem on a regular (non-zoned) device, we need to
decide an emulated zone size. Instead of making it a compile-time static
value, we'll make it configurable at mkfs time. Since we have one zone ==
one device extent restriction, we can determine the emulated zone size
from the size of a device extent. We can extend btrfs_get_dev_zone_info()
to show a regular device filled with conventional zones once the zone size
is decided.
The current call site of btrfs_get_dev_zone_info() during the mount process
is earlier than loading the file system trees so that we don't know the
size of a device extent at this point. Thus we can't slice a regular device
to conventional zones.
This patch introduces btrfs_get_dev_zone_info_all_devices to load the zone
info for all the devices. And, it places this function in open_ctree()
after loading the trees.
Reviewed-by: Anand Jain <anand.j...@oracle.com>
Reviewed-by: Josef Bacik <jo...@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com>
---
fs/btrfs/disk-io.c | 13 +++++++++++++
fs/btrfs/volumes.c | 4 ----
fs/btrfs/zoned.c | 25 +++++++++++++++++++++++++
fs/btrfs/zoned.h | 6 ++++++
4 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 71fab77873a5..2b6a3df765cd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3333,6 +3333,19 @@ int __cold open_ctree(struct super_block *sb, struct
btrfs_fs_devices *fs_device
if (ret)
goto fail_tree_roots;
+ /*
+ * Get zone type information of zoned block devices. This will also
+ * handle emulation of a zoned filesystem if a regular device has the
+ * zoned incompat feature flag set.
+ */
+ ret = btrfs_get_dev_zone_info_all_devices(fs_info);
+ if (ret) {
+ btrfs_err(fs_info,
+ "zoned: failed to read device zone info: %d",
+ ret);
+ goto fail_block_groups;
+ }
+
/*
* If we have a uuid root and we're not being told to rescan we need to
* check the generation here so we can set the
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3948f5b50d11..07cd4742c123 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -669,10 +669,6 @@ static int btrfs_open_one_device(struct btrfs_fs_devices
*fs_devices,
clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
device->mode = flags;
- ret = btrfs_get_dev_zone_info(device);
- if (ret != 0)
- goto error_free_page;
-
fs_devices->open_devices++;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
device->devid != BTRFS_DEV_REPLACE_DEVID) {
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 41d27fefd306..0b1b1f38a196 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -143,6 +143,31 @@ static int btrfs_get_dev_zones(struct btrfs_device
*device, u64 pos,
return 0;
}
+int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *device;
+ int ret = 0;
+
+ /* fs_info->zone_size might not set yet. Use the incomapt flag here. */
+ if (!btrfs_fs_incompat(fs_info, ZONED))
+ return 0;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ /* We can skip reading of zone info for missing devices */
+ if (!device->bdev)
+ continue;
+
+ ret = btrfs_get_dev_zone_info(device);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ return ret;
+}
+
int btrfs_get_dev_zone_info(struct btrfs_device *device)
{
struct btrfs_zoned_device_info *zone_info = NULL;
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 8abe2f83272b..eb47b7ad9ab1 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -25,6 +25,7 @@ struct btrfs_zoned_device_info {
#ifdef CONFIG_BLK_DEV_ZONED
int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
struct blk_zone *zone);
+int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info);
int btrfs_get_dev_zone_info(struct btrfs_device *device);
void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
@@ -42,6 +43,11 @@ static inline int btrfs_get_dev_zone(struct btrfs_device
*device, u64 pos,
return 0;
}
+static inline int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info
*fs_info)
+{
+ return 0;
+}
+
static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
{
return 0;
--
2.30.0
