From 60b52539b055332086a7e7da9da9cc1f4909f55a Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Sun, 24 Oct 2021 17:31:04 +0200 Subject: [PATCH 1/4] btrfs: add flags to give an hint to the chunk allocator Add the following flags to give an hint about which chunk should be allocated in which a disk. The following flags are created: - BTRFS_DEV_ALLOCATION_PREFERRED_DATA preferred data chunk, but metadata chunk allowed - BTRFS_DEV_ALLOCATION_PREFERRED_METADATA preferred metadata chunk, but data chunk allowed - BTRFS_DEV_ALLOCATION_METADATA_ONLY only metadata chunk allowed - BTRFS_DEV_ALLOCATION_DATA_ONLY only data chunk allowed Signed-off-by: Goffredo Baroncelli --- include/uapi/linux/btrfs_tree.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index e1c4c732aabac2..a8e32ff44ab8b3 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -384,6 +384,20 @@ struct btrfs_key { __u64 offset; } __attribute__ ((__packed__)); +/* dev_item.type */ + +/* btrfs chunk allocation hints */ +#define BTRFS_DEV_ALLOCATION_MASK_BIT_COUNT 3 +/* preferred data chunk, but metadata chunk allowed */ +#define BTRFS_DEV_ALLOCATION_PREFERRED_DATA (0ULL) +/* preferred metadata chunk, but data chunk allowed */ +#define BTRFS_DEV_ALLOCATION_PREFERRED_METADATA (1ULL) +/* only metadata chunk are allowed */ +#define BTRFS_DEV_ALLOCATION_METADATA_ONLY (2ULL) +/* only data chunk allowed */ +#define BTRFS_DEV_ALLOCATION_DATA_ONLY (3ULL) +/* 5..7 are unused values */ + struct btrfs_dev_item { /* the internal btrfs device id */ __le64 devid; From ea05f0db64e8713b509a3ba18a47842080a7ed6a Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Sun, 24 Oct 2021 17:31:05 +0200 Subject: [PATCH 2/4] btrfs: export dev_item.type in /sys/fs/btrfs//devinfo//type Signed-off-by: Goffredo Baroncelli --- fs/btrfs/sysfs.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 25a6f587852be2..207675930c1158 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1570,6 +1570,16 @@ static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj, } BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show); +static ssize_t btrfs_devinfo_type_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_device *device = container_of(kobj, struct btrfs_device, + devid_kobj); + + return scnprintf(buf, PAGE_SIZE, "0x%08llx\n", device->type); +} +BTRFS_ATTR(devid, type, btrfs_devinfo_type_show); + /* * Information about one device. * @@ -1582,6 +1592,7 @@ static struct attribute *devid_attrs[] = { BTRFS_ATTR_PTR(devid, replace_target), BTRFS_ATTR_PTR(devid, scrub_speed_max), BTRFS_ATTR_PTR(devid, writeable), + BTRFS_ATTR_PTR(devid, type), NULL }; ATTRIBUTE_GROUPS(devid); From 5af82dfcafa8ed103e29315436adf1eb3fa6044f Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Sun, 24 Oct 2021 17:31:06 +0200 Subject: [PATCH 3/4] btrfs: change the DEV_ITEM 'type' field via sysfs Signed-off-by: Kai Krakow --- fs/btrfs/sysfs.c | 56 +++++++++++++++++++++++++++++++++++++++++++++- fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 3 ++- 3 files changed, 58 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 207675930c1158..722bf99cb0236a 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1578,7 +1578,61 @@ static ssize_t btrfs_devinfo_type_show(struct kobject *kobj, return scnprintf(buf, PAGE_SIZE, "0x%08llx\n", device->type); } -BTRFS_ATTR(devid, type, btrfs_devinfo_type_show); + +static ssize_t btrfs_devinfo_type_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_root *root; + struct btrfs_device *device; + int ret; + struct btrfs_trans_handle *trans; + + u64 type, prev_type; + + device = container_of(kobj, struct btrfs_device, devid_kobj); + fs_info = device->fs_info; + if (!fs_info) + return -EPERM; + + root = fs_info->chunk_root; + if (sb_rdonly(fs_info->sb)) + return -EROFS; + + ret = kstrtou64(buf, 0, &type); + if (ret < 0) + return -EINVAL; + + /* for now, allow to touch only the 'allocation hint' bits */ + if (type & ~((1 << BTRFS_DEV_ALLOCATION_MASK_BIT_COUNT) - 1)) + return -EINVAL; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + prev_type = device->type; + device->type = type; + + ret = btrfs_update_device(trans, device); + + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + goto abort; + } + + ret = btrfs_commit_transaction(trans); + if (ret < 0) + goto abort; + + return len; +abort: + device->type = prev_type; + return ret; +} +BTRFS_ATTR_RW(devid, type, btrfs_devinfo_type_show, btrfs_devinfo_type_store); /* * Information about one device. diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 2ec3b8ac8fa357..f00cdedbbd11d8 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2773,7 +2773,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path return ret; } -static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, +noinline int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device) { int ret; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 2183361db614da..5b6861ae468900 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -581,5 +581,6 @@ int btrfs_bg_type_to_factor(u64 flags); const char *btrfs_bg_type_to_raid_name(u64 flags); int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info); int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical); - +int btrfs_update_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device); #endif From 14a694d039fd11e59dd90aa7cbca4af1df54c146 Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Sun, 24 Oct 2021 17:31:07 +0200 Subject: [PATCH 4/4] btrfs: add allocator_hint mode When this mode is enabled, the chunk allocation policy is modified as follow. Each disk may have a different tag: - BTRFS_DEV_ALLOCATION_PREFERRED_METADATA - BTRFS_DEV_ALLOCATION_METADATA_ONLY - BTRFS_DEV_ALLOCATION_DATA_ONLY - BTRFS_DEV_ALLOCATION_PREFERRED_DATA (default) Where: - ALLOCATION_PREFERRED_X means that it is preferred to use this disk for the X chunk type (the other type may be allowed when the space is low) - ALLOCATION_X_ONLY means that it is used *only* for the X chunk type. This means also that it is a preferred choice. Each time the allocator allocates a chunk of type X , first it takes the disks tagged as ALLOCATION_X_ONLY or ALLOCATION_PREFERRED_X; if the space is not enough, it uses also the disks tagged as ALLOCATION_METADATA_ONLY; if the space is not enough, it uses also the other disks, with the exception of the one marked as ALLOCATION_PREFERRED_Y, where Y the other type of chunk (i.e. not X). Signed-off-by: Goffredo Baroncelli --- fs/btrfs/volumes.c | 97 +++++++++++++++++++++++++++++++++++++++++++++- fs/btrfs/volumes.h | 1 + 2 files changed, 97 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index f00cdedbbd11d8..e74f2126cdf992 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -179,6 +179,19 @@ enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */ } +#define BTRFS_DEV_ALLOCATION_MASK ((1ULL << \ + BTRFS_DEV_ALLOCATION_MASK_BIT_COUNT) - 1) +#define BTRFS_DEV_ALLOCATION_MASK_COUNT (1ULL << \ + BTRFS_DEV_ALLOCATION_MASK_BIT_COUNT) + +static const char alloc_hint_map[BTRFS_DEV_ALLOCATION_MASK_COUNT] = { + [BTRFS_DEV_ALLOCATION_DATA_ONLY] = -1, + [BTRFS_DEV_ALLOCATION_PREFERRED_DATA] = 0, + [BTRFS_DEV_ALLOCATION_PREFERRED_METADATA] = 1, + [BTRFS_DEV_ALLOCATION_METADATA_ONLY] = 2, + /* the other values are set to 0 */ +}; + const char *btrfs_bg_type_to_raid_name(u64 flags) { const int index = btrfs_bg_flags_to_raid_index(flags); @@ -4938,13 +4951,18 @@ static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info, } /* - * sort the devices in descending order by max_avail, total_avail + * sort the devices in descending order by alloc_hint, + * max_avail, total_avail */ static int btrfs_cmp_device_info(const void *a, const void *b) { const struct btrfs_device_info *di_a = a; const struct btrfs_device_info *di_b = b; + if (di_a->alloc_hint > di_b->alloc_hint) + return -1; + if (di_a->alloc_hint < di_b->alloc_hint) + return 1; if (di_a->max_avail > di_b->max_avail) return -1; if (di_a->max_avail < di_b->max_avail) @@ -5107,6 +5125,8 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices, int ndevs = 0; u64 max_avail; u64 dev_offset; + int hint; + int i; /* * in the first pass through the devices list, we gather information @@ -5159,16 +5179,91 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices, devices_info[ndevs].max_avail = max_avail; devices_info[ndevs].total_avail = total_avail; devices_info[ndevs].dev = device; + + if ((ctl->type & BTRFS_BLOCK_GROUP_DATA) && + (ctl->type & BTRFS_BLOCK_GROUP_METADATA)) { + /* + * if mixed bg set all the alloc_hint + * fields to the same value, so the sorting + * is not affected + */ + devices_info[ndevs].alloc_hint = 0; + } else if (ctl->type & BTRFS_BLOCK_GROUP_DATA) { + hint = device->type & BTRFS_DEV_ALLOCATION_MASK; + + /* + * skip BTRFS_DEV_METADATA_ONLY disks + */ + if (hint == BTRFS_DEV_ALLOCATION_METADATA_ONLY) + continue; + /* + * if a data chunk must be allocated, + * sort also by hint (data disk + * higher priority) + */ + devices_info[ndevs].alloc_hint = -alloc_hint_map[hint]; + } else { /* BTRFS_BLOCK_GROUP_METADATA */ + hint = device->type & BTRFS_DEV_ALLOCATION_MASK; + + /* + * skip BTRFS_DEV_DATA_ONLY disks + */ + if (hint == BTRFS_DEV_ALLOCATION_DATA_ONLY) + continue; + /* + * if a data chunk must be allocated, + * sort also by hint (metadata hint + * higher priority) + */ + devices_info[ndevs].alloc_hint = alloc_hint_map[hint]; + } + ++ndevs; } ctl->ndevs = ndevs; + /* + * no devices available + */ + if (!ndevs) + return 0; + /* * now sort the devices by hole size / available space */ sort(devices_info, ndevs, sizeof(struct btrfs_device_info), btrfs_cmp_device_info, NULL); + /* + * select the minimum set of disks grouped by hint that + * can host the chunk + */ + ndevs = 0; + while (ndevs < ctl->ndevs) { + hint = devices_info[ndevs++].alloc_hint; + while (ndevs < ctl->ndevs && + devices_info[ndevs].alloc_hint == hint) + ndevs++; + if (ndevs >= ctl->devs_min) + break; + } + + BUG_ON(ndevs > ctl->ndevs); + ctl->ndevs = ndevs; + + /* + * the next layers require the devices_info ordered by + * max_avail. If we are returing two (or more) different + * group of alloc_hint, this is not always true. So sort + * these gain. + */ + + for (i = 0 ; i < ndevs ; i++) + devices_info[i].alloc_hint = 0; + + sort(devices_info, ndevs, sizeof(struct btrfs_device_info), + btrfs_cmp_device_info, NULL); + return 0; } diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 5b6861ae468900..1644d7c428a215 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -369,6 +369,7 @@ struct btrfs_device_info { u64 dev_offset; u64 max_avail; u64 total_avail; + int alloc_hint; }; struct btrfs_raid_attr {