On 2019/08/15 22:46, Anand Jain wrote:
> On 8/8/19 5:30 PM, Naohiro Aota wrote:
>> HMZONED mode cannot be used together with the RAID5/6 profile for now.
>> Introduce the function btrfs_check_hmzoned_mode() to check this. This
>> function will also check if HMZONED flag is enabled on the file system and
>> if the file system consists of zoned devices with equal zone size.
>>
>> Additionally, as updates to the space cache are in-place, the space cache
>> cannot be located over sequential zones and there is no guarantees that the
>> device will have enough conventional zones to store this cache. Resolve
>> this problem by disabling completely the space cache. This does not
>> introduces any problems with sequential block groups: all the free space is
>> located after the allocation pointer and no free space before the pointer.
>> There is no need to have such cache.
>>
>> For the same reason, NODATACOW is also disabled.
>>
>> Also INODE_MAP_CACHE is also disabled to avoid preallocation in the
>> INODE_MAP_CACHE inode.
>
> A list of incompatibility features with zoned devices. This need better
> documentation, may be a table and its reason is better.
Are you referring to the format of the commit message itself ? Or would you like
to see a documentation added to Documentation/filesystems/btrfs.txt ?
>
>
>> Signed-off-by: Damien Le Moal <damien.lem...@wdc.com>
>> Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com>
>> ---
>> fs/btrfs/ctree.h | 3 ++
>> fs/btrfs/dev-replace.c | 8 +++++
>> fs/btrfs/disk-io.c | 8 +++++
>> fs/btrfs/hmzoned.c | 67 ++++++++++++++++++++++++++++++++++++++++++
>> fs/btrfs/hmzoned.h | 18 ++++++++++++
>> fs/btrfs/super.c | 1 +
>> fs/btrfs/volumes.c | 5 ++++
>> 7 files changed, 110 insertions(+)
>>
>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>> index 299e11e6c554..a00ce8c4d678 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -713,6 +713,9 @@ struct btrfs_fs_info {
>> struct btrfs_root *uuid_root;
>> struct btrfs_root *free_space_root;
>>
>> + /* Zone size when in HMZONED mode */
>> + u64 zone_size;
>> +
>> /* the log root tree is a directory of all the other log roots */
>> struct btrfs_root *log_root_tree;
>>
>> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
>> index 6b2e9aa83ffa..2cc3ac4d101d 100644
>> --- a/fs/btrfs/dev-replace.c
>> +++ b/fs/btrfs/dev-replace.c
>> @@ -20,6 +20,7 @@
>> #include "rcu-string.h"
>> #include "dev-replace.h"
>> #include "sysfs.h"
>> +#include "hmzoned.h"
>>
>> static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
>> int scrub_ret);
>> @@ -201,6 +202,13 @@ static int btrfs_init_dev_replace_tgtdev(struct
>> btrfs_fs_info *fs_info,
>> return PTR_ERR(bdev);
>> }
>>
>> + if (!btrfs_check_device_zone_type(fs_info, bdev)) {
>> + btrfs_err(fs_info,
>> + "zone type of target device mismatch with the
>> filesystem!");
>> + ret = -EINVAL;
>> + goto error;
>> + }
>> +
>> sync_blockdev(bdev);
>>
>> devices = &fs_info->fs_devices->devices;
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> index 5f7ee70b3d1a..8854ff2e5fa5 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -40,6 +40,7 @@
>> #include "compression.h"
>> #include "tree-checker.h"
>> #include "ref-verify.h"
>> +#include "hmzoned.h"
>>
>> #define BTRFS_SUPER_FLAG_SUPP (BTRFS_HEADER_FLAG_WRITTEN |\
>> BTRFS_HEADER_FLAG_RELOC |\
>> @@ -3123,6 +3124,13 @@ int open_ctree(struct super_block *sb,
>>
>> btrfs_free_extra_devids(fs_devices, 1);
>>
>> + ret = btrfs_check_hmzoned_mode(fs_info);
>> + if (ret) {
>> + btrfs_err(fs_info, "failed to init hmzoned mode: %d",
>> + ret);
>> + goto fail_block_groups;
>> + }
>> +
>> ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
>> if (ret) {
>> btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
>> diff --git a/fs/btrfs/hmzoned.c b/fs/btrfs/hmzoned.c
>> index bfd04792dd62..512674d8f488 100644
>> --- a/fs/btrfs/hmzoned.c
>> +++ b/fs/btrfs/hmzoned.c
>> @@ -160,3 +160,70 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64
>> pos,
>>
>> return 0;
>> }
>> +
>> +int btrfs_check_hmzoned_mode(struct btrfs_fs_info *fs_info)
>> +{
>> + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
>> + struct btrfs_device *device;
>> + u64 hmzoned_devices = 0;
>> + u64 nr_devices = 0;
>> + u64 zone_size = 0;
>> + int incompat_hmzoned = btrfs_fs_incompat(fs_info, HMZONED);
>> + int ret = 0;
>> +
>> + /* Count zoned devices */
>> + list_for_each_entry(device, &fs_devices->devices, dev_list) {
>> + if (!device->bdev)
>> + continue;
>> + if (bdev_zoned_model(device->bdev) == BLK_ZONED_HM ||
>> + (bdev_zoned_model(device->bdev) == BLK_ZONED_HA &&
>> + incompat_hmzoned)) {
>> + hmzoned_devices++;
>> + if (!zone_size) {
>> + zone_size = device->zone_info->zone_size;
>> + } else if (device->zone_info->zone_size != zone_size) {
>> + btrfs_err(fs_info,
>> + "Zoned block devices must have equal
>> zone sizes");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + }
>> + nr_devices++;
>> + }
>> +
>> + if (!hmzoned_devices && incompat_hmzoned) {
>> + /* No zoned block device found on HMZONED FS */
>> + btrfs_err(fs_info, "HMZONED enabled file system should have
>> zoned devices");
>> + ret = -EINVAL;
>> + goto out;
>
>
> When does the HMZONED gets enabled? I presume during mkfs. Where are
> the related btrfs-progs patches? Searching for the related btrfs-progs
> patches doesn't show up anything in the ML. Looks like I am missing
> something, nor the cover letter said anything about the progs part.
>
> Thanks, Anand
>
>> + }
>> +
>> + if (!hmzoned_devices && !incompat_hmzoned)
>> + goto out;
>> +
>> + fs_info->zone_size = zone_size;
>> +
>> + if (hmzoned_devices != nr_devices) {
>> + btrfs_err(fs_info,
>> + "zoned devices cannot be mixed with regular devices");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + /*
>> + * stripe_size is always aligned to BTRFS_STRIPE_LEN in
>> + * __btrfs_alloc_chunk(). Since we want stripe_len == zone_size,
>> + * check the alignment here.
>> + */
>> + if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
>> + btrfs_err(fs_info,
>> + "zone size is not aligned to BTRFS_STRIPE_LEN");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + btrfs_info(fs_info, "HMZONED mode enabled, zone size %llu B",
>> + fs_info->zone_size);
>> +out:
>> + return ret;
>> +}
>> diff --git a/fs/btrfs/hmzoned.h b/fs/btrfs/hmzoned.h
>> index ffc70842135e..29cfdcabff2f 100644
>> --- a/fs/btrfs/hmzoned.h
>> +++ b/fs/btrfs/hmzoned.h
>> @@ -9,6 +9,8 @@
>> #ifndef BTRFS_HMZONED_H
>> #define BTRFS_HMZONED_H
>>
>> +#include <linux/blkdev.h>
>> +
>> struct btrfs_zoned_device_info {
>> /*
>> * Number of zones, zone size and types of zones if bdev is a
>> @@ -25,6 +27,7 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64
>> pos,
>> struct blk_zone *zone, gfp_t gfp_mask);
>> int btrfs_get_dev_zone_info(struct btrfs_device *device);
>> void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
>> +int btrfs_check_hmzoned_mode(struct btrfs_fs_info *fs_info);
>>
>> static inline bool btrfs_dev_is_sequential(struct btrfs_device *device,
>> u64 pos)
>> {
>> @@ -76,4 +79,19 @@ static inline void btrfs_dev_clear_zone_empty(struct
>> btrfs_device *device,
>> btrfs_dev_set_empty_zone_bit(device, pos, false);
>> }
>>
>> +static inline bool btrfs_check_device_zone_type(struct btrfs_fs_info
>> *fs_info,
>> + struct block_device *bdev)
>> +{
>> + u64 zone_size;
>> +
>> + if (btrfs_fs_incompat(fs_info, HMZONED)) {
>> + zone_size = (u64)bdev_zone_sectors(bdev) << SECTOR_SHIFT;
>> + /* Do not allow non-zoned device */
>> + return bdev_is_zoned(bdev) && fs_info->zone_size == zone_size;
>> + }
>> +
>> + /* Do not allow Host Manged zoned device */
>> + return bdev_zoned_model(bdev) != BLK_ZONED_HM;
>> +}
>> +
>> #endif
>> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
>> index 78de9d5d80c6..d7879a5a2536 100644
>> --- a/fs/btrfs/super.c
>> +++ b/fs/btrfs/super.c
>> @@ -43,6 +43,7 @@
>> #include "free-space-cache.h"
>> #include "backref.h"
>> #include "space-info.h"
>> +#include "hmzoned.h"
>> #include "tests/btrfs-tests.h"
>>
>> #include "qgroup.h"
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index 8e5a894e7bde..755b2ec1e0de 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -2572,6 +2572,11 @@ int btrfs_init_new_device(struct btrfs_fs_info
>> *fs_info, const char *device_path
>> if (IS_ERR(bdev))
>> return PTR_ERR(bdev);
>>
>> + if (!btrfs_check_device_zone_type(fs_info, bdev)) {
>> + ret = -EINVAL;
>> + goto error;
>> + }
>> +
>> if (fs_devices->seeding) {
>> seeding_dev = 1;
>> down_write(&sb->s_umount);
>>
>
>
--
Damien Le Moal
Western Digital Research
