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