diff options
Diffstat (limited to 'fs/btrfs/space-info.c')
| -rw-r--r-- | fs/btrfs/space-info.c | 1915 |
1 files changed, 1395 insertions, 520 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 41ee88633769..6babbe333741 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/spinlock.h> +#include <linux/minmax.h> #include "misc.h" #include "ctree.h" #include "space-info.h" @@ -9,6 +11,11 @@ #include "ordered-data.h" #include "transaction.h" #include "block-group.h" +#include "fs.h" +#include "accessors.h" +#include "extent-tree.h" +#include "zoned.h" +#include "delayed-inode.h" /* * HOW DOES SPACE RESERVATION WORK @@ -44,11 +51,11 @@ * num_bytes we want to reserve. * * ->reserve - * space_info->bytes_may_reserve += num_bytes + * space_info->bytes_may_use += num_bytes * * ->extent allocation * Call btrfs_add_reserved_bytes() which does - * space_info->bytes_may_reserve -= num_bytes + * space_info->bytes_may_use -= num_bytes * space_info->bytes_reserved += extent_bytes * * ->insert reference @@ -61,7 +68,7 @@ * Assume we are unable to simply make the reservation because we do not have * enough space * - * -> __reserve_bytes + * -> reserve_bytes * create a reserve_ticket with ->bytes set to our reservation, add it to * the tail of space_info->tickets, kick async flush thread * @@ -122,6 +129,14 @@ * churn a lot and we can avoid making some extent tree modifications if we * are able to delay for as long as possible. * + * RESET_ZONES + * This state works only for the zoned mode. On the zoned mode, we cannot + * reuse once allocated then freed region until we reset the zone, due to + * the sequential write zone requirement. The RESET_ZONES state resets the + * zones of an unused block group and let us reuse the space. The reusing + * is faster than removing the block group and allocating another block + * group on the zones. + * * ALLOC_CHUNK * We will skip this the first time through space reservation, because of * overcommit and we don't want to have a lot of useless metadata space when @@ -133,12 +148,13 @@ * operations, however they won't be usable until the transaction commits. * * COMMIT_TRANS - * may_commit_transaction() is the ultimate arbiter on whether we commit the - * transaction or not. In order to avoid constantly churning we do all the - * above flushing first and then commit the transaction as the last resort. - * However we need to take into account things like pinned space that would - * be freed, plus any delayed work we may not have gotten rid of in the case - * of metadata. + * This will commit the transaction. Historically we had a lot of logic + * surrounding whether or not we'd commit the transaction, but this waits born + * out of a pre-tickets era where we could end up committing the transaction + * thousands of times in a row without making progress. Now thanks to our + * ticketing system we know if we're not making progress and can error + * everybody out after a few commits rather than burning the disk hoping for + * a different answer. * * OVERCOMMIT * @@ -157,14 +173,14 @@ * thing with or without extra unallocated space. */ -u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info, - bool may_use_included) -{ - ASSERT(s_info); - return s_info->bytes_used + s_info->bytes_reserved + - s_info->bytes_pinned + s_info->bytes_readonly + - (may_use_included ? s_info->bytes_may_use : 0); -} +struct reserve_ticket { + u64 bytes; + int error; + bool steal; + struct list_head list; + wait_queue_head_t wait; + spinlock_t lock; +}; /* * after adding space to the filesystem, we need to clear the full flags @@ -175,31 +191,54 @@ void btrfs_clear_space_info_full(struct btrfs_fs_info *info) struct list_head *head = &info->space_info; struct btrfs_space_info *found; - rcu_read_lock(); - list_for_each_entry_rcu(found, head, list) - found->full = 0; - rcu_read_unlock(); + list_for_each_entry(found, head, list) + found->full = false; } -static int create_space_info(struct btrfs_fs_info *info, u64 flags) +/* + * Block groups with more than this value (percents) of unusable space will be + * scheduled for background reclaim. + */ +#define BTRFS_DEFAULT_ZONED_RECLAIM_THRESH (75) + +#define BTRFS_UNALLOC_BLOCK_GROUP_TARGET (10ULL) + +/* + * Calculate chunk size depending on volume type (regular or zoned). + */ +static u64 calc_chunk_size(const struct btrfs_fs_info *fs_info, u64 flags) { + if (btrfs_is_zoned(fs_info)) + return fs_info->zone_size; - struct btrfs_space_info *space_info; - int i; - int ret; + ASSERT(flags & BTRFS_BLOCK_GROUP_TYPE_MASK, "flags=%llu", flags); - space_info = kzalloc(sizeof(*space_info), GFP_NOFS); - if (!space_info) - return -ENOMEM; + if (flags & BTRFS_BLOCK_GROUP_DATA) + return BTRFS_MAX_DATA_CHUNK_SIZE; + else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + return SZ_32M; - ret = percpu_counter_init(&space_info->total_bytes_pinned, 0, - GFP_KERNEL); - if (ret) { - kfree(space_info); - return ret; - } + /* Handle BTRFS_BLOCK_GROUP_METADATA */ + if (fs_info->fs_devices->total_rw_bytes > 50ULL * SZ_1G) + return SZ_1G; + + return SZ_256M; +} + +/* + * Update default chunk size. + */ +void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info, + u64 chunk_size) +{ + WRITE_ONCE(space_info->chunk_size, chunk_size); +} - for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) +static void init_space_info(struct btrfs_fs_info *info, + struct btrfs_space_info *space_info, u64 flags) +{ + space_info->fs_info = info; + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) INIT_LIST_HEAD(&space_info->block_groups[i]); init_rwsem(&space_info->groups_sem); spin_lock_init(&space_info->lock); @@ -208,12 +247,73 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags) INIT_LIST_HEAD(&space_info->ro_bgs); INIT_LIST_HEAD(&space_info->tickets); INIT_LIST_HEAD(&space_info->priority_tickets); + space_info->clamp = 1; + btrfs_update_space_info_chunk_size(space_info, calc_chunk_size(info, flags)); + space_info->subgroup_id = BTRFS_SUB_GROUP_PRIMARY; - ret = btrfs_sysfs_add_space_info_type(info, space_info); + if (btrfs_is_zoned(info)) + space_info->bg_reclaim_threshold = BTRFS_DEFAULT_ZONED_RECLAIM_THRESH; +} + +static int create_space_info_sub_group(struct btrfs_space_info *parent, u64 flags, + enum btrfs_space_info_sub_group id, int index) +{ + struct btrfs_fs_info *fs_info = parent->fs_info; + struct btrfs_space_info *sub_group; + int ret; + + ASSERT(parent->subgroup_id == BTRFS_SUB_GROUP_PRIMARY, + "parent->subgroup_id=%d", parent->subgroup_id); + ASSERT(id != BTRFS_SUB_GROUP_PRIMARY, "id=%d", id); + + sub_group = kzalloc(sizeof(*sub_group), GFP_NOFS); + if (!sub_group) + return -ENOMEM; + + init_space_info(fs_info, sub_group, flags); + parent->sub_group[index] = sub_group; + sub_group->parent = parent; + sub_group->subgroup_id = id; + + ret = btrfs_sysfs_add_space_info_type(sub_group); + if (ret) { + kfree(sub_group); + parent->sub_group[index] = NULL; + } + return ret; +} + +static int create_space_info(struct btrfs_fs_info *info, u64 flags) +{ + + struct btrfs_space_info *space_info; + int ret = 0; + + space_info = kzalloc(sizeof(*space_info), GFP_NOFS); + if (!space_info) + return -ENOMEM; + + init_space_info(info, space_info, flags); + + if (btrfs_is_zoned(info)) { + if (flags & BTRFS_BLOCK_GROUP_DATA) + ret = create_space_info_sub_group(space_info, flags, + BTRFS_SUB_GROUP_DATA_RELOC, + 0); + else if (flags & BTRFS_BLOCK_GROUP_METADATA) + ret = create_space_info_sub_group(space_info, flags, + BTRFS_SUB_GROUP_TREELOG, + 0); + + if (ret) + return ret; + } + + ret = btrfs_sysfs_add_space_info_type(space_info); if (ret) return ret; - list_add_rcu(&space_info->list, &info->space_info); + list_add(&space_info->list, &info->space_info); if (flags & BTRFS_BLOCK_GROUP_DATA) info->data_sinfo = space_info; @@ -257,29 +357,32 @@ out: return ret; } -void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags, - u64 total_bytes, u64 bytes_used, - u64 bytes_readonly, - struct btrfs_space_info **space_info) +void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info, + struct btrfs_block_group *block_group) { - struct btrfs_space_info *found; - int factor; + struct btrfs_space_info *space_info = block_group->space_info; + int factor, index; + + factor = btrfs_bg_type_to_factor(block_group->flags); + + spin_lock(&space_info->lock); + space_info->total_bytes += block_group->length; + space_info->disk_total += block_group->length * factor; + space_info->bytes_used += block_group->used; + space_info->disk_used += block_group->used * factor; + space_info->bytes_readonly += block_group->bytes_super; + btrfs_space_info_update_bytes_zone_unusable(space_info, block_group->zone_unusable); + if (block_group->length > 0) + space_info->full = false; + btrfs_try_granting_tickets(space_info); + spin_unlock(&space_info->lock); + + block_group->space_info = space_info; - factor = btrfs_bg_type_to_factor(flags); - - found = btrfs_find_space_info(info, flags); - ASSERT(found); - spin_lock(&found->lock); - found->total_bytes += total_bytes; - found->disk_total += total_bytes * factor; - found->bytes_used += bytes_used; - found->disk_used += bytes_used * factor; - found->bytes_readonly += bytes_readonly; - if (total_bytes > 0) - found->full = 0; - btrfs_try_granting_tickets(info, found); - spin_unlock(&found->lock); - *space_info = found; + index = btrfs_bg_flags_to_raid_index(block_group->flags); + down_write(&space_info->groups_sem); + list_add_tail(&block_group->list, &space_info->block_groups[index]); + up_write(&space_info->groups_sem); } struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, @@ -290,28 +393,42 @@ struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, flags &= BTRFS_BLOCK_GROUP_TYPE_MASK; - rcu_read_lock(); - list_for_each_entry_rcu(found, head, list) { - if (found->flags & flags) { - rcu_read_unlock(); + list_for_each_entry(found, head, list) { + if (found->flags & flags) return found; - } } - rcu_read_unlock(); return NULL; } -static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) +static u64 calc_effective_data_chunk_size(struct btrfs_fs_info *fs_info) { - return (global->size << 1); + struct btrfs_space_info *data_sinfo; + u64 data_chunk_size; + + /* + * Calculate the data_chunk_size, space_info->chunk_size is the + * "optimal" chunk size based on the fs size. However when we actually + * allocate the chunk we will strip this down further, making it no + * more than 10% of the disk or 1G, whichever is smaller. + * + * On the zoned mode, we need to use zone_size (= data_sinfo->chunk_size) + * as it is. + */ + data_sinfo = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA); + if (btrfs_is_zoned(fs_info)) + return data_sinfo->chunk_size; + data_chunk_size = min(data_sinfo->chunk_size, + mult_perc(fs_info->fs_devices->total_rw_bytes, 10)); + return min_t(u64, data_chunk_size, SZ_1G); } -static u64 calc_available_free_space(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, - enum btrfs_reserve_flush_enum flush) +static u64 calc_available_free_space(const struct btrfs_space_info *space_info, + enum btrfs_reserve_flush_enum flush) { + struct btrfs_fs_info *fs_info = space_info->fs_info; u64 profile; u64 avail; + u64 data_chunk_size; int factor; if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) @@ -329,6 +446,27 @@ static u64 calc_available_free_space(struct btrfs_fs_info *fs_info, */ factor = btrfs_bg_type_to_factor(profile); avail = div_u64(avail, factor); + if (avail == 0) + return 0; + + data_chunk_size = calc_effective_data_chunk_size(fs_info); + + /* + * Since data allocations immediately use block groups as part of the + * reservation, because we assume that data reservations will == actual + * usage, we could potentially overcommit and then immediately have that + * available space used by a data allocation, which could put us in a + * bind when we get close to filling the file system. + * + * To handle this simply remove the data_chunk_size from the available + * space. If we are relatively empty this won't affect our ability to + * overcommit much, and if we're very close to full it'll keep us from + * getting into a position where we've given ourselves very little + * metadata wiggle room. + */ + if (avail <= data_chunk_size) + return 0; + avail -= data_chunk_size; /* * If we aren't flushing all things, let us overcommit up to @@ -339,47 +477,91 @@ static u64 calc_available_free_space(struct btrfs_fs_info *fs_info, avail >>= 3; else avail >>= 1; + + /* + * On the zoned mode, we always allocate one zone as one chunk. + * Returning non-zone size aligned bytes here will result in + * less pressure for the async metadata reclaim process, and it + * will over-commit too much leading to ENOSPC. Align down to the + * zone size to avoid that. + */ + if (btrfs_is_zoned(fs_info)) + avail = ALIGN_DOWN(avail, fs_info->zone_size); + return avail; } -int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, u64 bytes, - enum btrfs_reserve_flush_enum flush) +static inline bool check_can_overcommit(const struct btrfs_space_info *space_info, + u64 space_info_used_bytes, u64 bytes, + enum btrfs_reserve_flush_enum flush) +{ + const u64 avail = calc_available_free_space(space_info, flush); + + return (space_info_used_bytes + bytes < space_info->total_bytes + avail); +} + +static inline bool can_overcommit(const struct btrfs_space_info *space_info, + u64 space_info_used_bytes, u64 bytes, + enum btrfs_reserve_flush_enum flush) +{ + /* Don't overcommit when in mixed mode. */ + if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) + return false; + + return check_can_overcommit(space_info, space_info_used_bytes, bytes, flush); +} + +bool btrfs_can_overcommit(const struct btrfs_space_info *space_info, u64 bytes, + enum btrfs_reserve_flush_enum flush) { - u64 avail; u64 used; /* Don't overcommit when in mixed mode */ if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) - return 0; + return false; used = btrfs_space_info_used(space_info, true); - avail = calc_available_free_space(fs_info, space_info, flush); - if (used + bytes < space_info->total_bytes + avail) - return 1; - return 0; + return check_can_overcommit(space_info, used, bytes, flush); } static void remove_ticket(struct btrfs_space_info *space_info, - struct reserve_ticket *ticket) + struct reserve_ticket *ticket, int error) { + lockdep_assert_held(&space_info->lock); + if (!list_empty(&ticket->list)) { list_del_init(&ticket->list); - ASSERT(space_info->reclaim_size >= ticket->bytes); + ASSERT(space_info->reclaim_size >= ticket->bytes, + "space_info->reclaim_size=%llu ticket->bytes=%llu", + space_info->reclaim_size, ticket->bytes); space_info->reclaim_size -= ticket->bytes; } + + spin_lock(&ticket->lock); + /* + * If we are called from a task waiting on the ticket, it may happen + * that before it sets an error on the ticket, a reclaim task was able + * to satisfy the ticket. In that case ignore the error. + */ + if (error && ticket->bytes > 0) + ticket->error = error; + else + ticket->bytes = 0; + + wake_up(&ticket->wait); + spin_unlock(&ticket->lock); } /* * This is for space we already have accounted in space_info->bytes_may_use, so * basically when we're returning space from block_rsv's. */ -void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info) +void btrfs_try_granting_tickets(struct btrfs_space_info *space_info) { struct list_head *head; enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH; + u64 used = btrfs_space_info_used(space_info, true); lockdep_assert_held(&space_info->lock); @@ -387,21 +569,18 @@ void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, again: while (!list_empty(head)) { struct reserve_ticket *ticket; - u64 used = btrfs_space_info_used(space_info, true); + u64 used_after; ticket = list_first_entry(head, struct reserve_ticket, list); + used_after = used + ticket->bytes; - /* Check and see if our ticket can be satisified now. */ - if ((used + ticket->bytes <= space_info->total_bytes) || - btrfs_can_overcommit(fs_info, space_info, ticket->bytes, - flush)) { - btrfs_space_info_update_bytes_may_use(fs_info, - space_info, - ticket->bytes); - remove_ticket(space_info, ticket); - ticket->bytes = 0; + /* Check and see if our ticket can be satisfied now. */ + if (used_after <= space_info->total_bytes || + can_overcommit(space_info, used, ticket->bytes, flush)) { + btrfs_space_info_update_bytes_may_use(space_info, ticket->bytes); + remove_ticket(space_info, ticket, 0); space_info->tickets_id++; - wake_up(&ticket->wait); + used = used_after; } else { break; } @@ -423,38 +602,61 @@ do { \ spin_unlock(&__rsv->lock); \ } while (0) -static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *info) +static const char *space_info_flag_to_str(const struct btrfs_space_info *space_info) { - lockdep_assert_held(&info->lock); - - btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull", - info->flags, - info->total_bytes - btrfs_space_info_used(info, true), - info->full ? "" : "not "); - btrfs_info(fs_info, - "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu", - info->total_bytes, info->bytes_used, info->bytes_pinned, - info->bytes_reserved, info->bytes_may_use, - info->bytes_readonly); + switch (space_info->flags) { + case BTRFS_BLOCK_GROUP_SYSTEM: + return "SYSTEM"; + case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA: + return "DATA+METADATA"; + case BTRFS_BLOCK_GROUP_DATA: + return "DATA"; + case BTRFS_BLOCK_GROUP_METADATA: + return "METADATA"; + default: + return "UNKNOWN"; + } +} +static void dump_global_block_rsv(struct btrfs_fs_info *fs_info) +{ DUMP_BLOCK_RSV(fs_info, global_block_rsv); DUMP_BLOCK_RSV(fs_info, trans_block_rsv); DUMP_BLOCK_RSV(fs_info, chunk_block_rsv); DUMP_BLOCK_RSV(fs_info, delayed_block_rsv); DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv); +} +static void __btrfs_dump_space_info(const struct btrfs_space_info *info) +{ + const struct btrfs_fs_info *fs_info = info->fs_info; + const char *flag_str = space_info_flag_to_str(info); + lockdep_assert_held(&info->lock); + + /* The free space could be negative in case of overcommit */ + btrfs_info(fs_info, + "space_info %s (sub-group id %d) has %lld free, is %sfull", + flag_str, info->subgroup_id, + (s64)(info->total_bytes - btrfs_space_info_used(info, true)), + info->full ? "" : "not "); + btrfs_info(fs_info, +"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu zone_unusable=%llu", + info->total_bytes, info->bytes_used, info->bytes_pinned, + info->bytes_reserved, info->bytes_may_use, + info->bytes_readonly, info->bytes_zone_unusable); } -void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *info, u64 bytes, - int dump_block_groups) +void btrfs_dump_space_info(struct btrfs_space_info *info, u64 bytes, + bool dump_block_groups) { + struct btrfs_fs_info *fs_info = info->fs_info; struct btrfs_block_group *cache; + u64 total_avail = 0; int index = 0; spin_lock(&info->lock); - __btrfs_dump_space_info(fs_info, info); + __btrfs_dump_space_info(info); + dump_global_block_rsv(fs_info); spin_unlock(&info->lock); if (!dump_block_groups) @@ -463,42 +665,29 @@ void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, down_read(&info->groups_sem); again: list_for_each_entry(cache, &info->block_groups[index], list) { + u64 avail; + spin_lock(&cache->lock); + avail = cache->length - cache->used - cache->pinned - + cache->reserved - cache->bytes_super - cache->zone_unusable; btrfs_info(fs_info, - "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s", - cache->start, cache->length, cache->used, cache->pinned, - cache->reserved, cache->ro ? "[readonly]" : ""); - btrfs_dump_free_space(cache, bytes); +"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu delalloc %llu super %llu zone_unusable (%llu bytes available) %s", + cache->start, cache->length, cache->used, cache->pinned, + cache->reserved, cache->delalloc_bytes, + cache->bytes_super, cache->zone_unusable, + avail, cache->ro ? "[readonly]" : ""); spin_unlock(&cache->lock); + btrfs_dump_free_space(cache, bytes); + total_avail += avail; } if (++index < BTRFS_NR_RAID_TYPES) goto again; up_read(&info->groups_sem); -} -static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info, - unsigned long nr_pages, int nr_items) -{ - struct super_block *sb = fs_info->sb; - - if (down_read_trylock(&sb->s_umount)) { - writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE); - up_read(&sb->s_umount); - } else { - /* - * We needn't worry the filesystem going from r/w to r/o though - * we don't acquire ->s_umount mutex, because the filesystem - * should guarantee the delalloc inodes list be empty after - * the filesystem is readonly(all dirty pages are written to - * the disk). - */ - btrfs_start_delalloc_roots(fs_info, nr_items); - if (!current->journal_info) - btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1); - } + btrfs_info(fs_info, "%llu bytes available across all block groups", total_avail); } -static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, +static inline u64 calc_reclaim_items_nr(const struct btrfs_fs_info *fs_info, u64 to_reclaim) { u64 bytes; @@ -511,83 +700,120 @@ static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, return nr; } -#define EXTENT_SIZE_PER_ITEM SZ_256K - /* * shrink metadata reservation for delalloc */ -static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim, - u64 orig, bool wait_ordered) +static void shrink_delalloc(struct btrfs_space_info *space_info, + u64 to_reclaim, bool wait_ordered, + bool for_preempt) { - struct btrfs_space_info *space_info; + struct btrfs_fs_info *fs_info = space_info->fs_info; struct btrfs_trans_handle *trans; u64 delalloc_bytes; - u64 dio_bytes; - u64 async_pages; + u64 ordered_bytes; u64 items; long time_left; - unsigned long nr_pages; int loops; - /* Calc the number of the pages we need flush for space reservation */ - items = calc_reclaim_items_nr(fs_info, to_reclaim); - to_reclaim = items * EXTENT_SIZE_PER_ITEM; - - trans = (struct btrfs_trans_handle *)current->journal_info; - space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); - - delalloc_bytes = percpu_counter_sum_positive( - &fs_info->delalloc_bytes); - dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); - if (delalloc_bytes == 0 && dio_bytes == 0) { - if (trans) - return; - if (wait_ordered) - btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); + delalloc_bytes = percpu_counter_sum_positive(&fs_info->delalloc_bytes); + ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes); + if (delalloc_bytes == 0 && ordered_bytes == 0) return; + + /* Calc the number of the pages we need flush for space reservation */ + if (to_reclaim == U64_MAX) { + items = U64_MAX; + } else { + /* + * to_reclaim is set to however much metadata we need to + * reclaim, but reclaiming that much data doesn't really track + * exactly. What we really want to do is reclaim full inode's + * worth of reservations, however that's not available to us + * here. We will take a fraction of the delalloc bytes for our + * flushing loops and hope for the best. Delalloc will expand + * the amount we write to cover an entire dirty extent, which + * will reclaim the metadata reservation for that range. If + * it's not enough subsequent flush stages will be more + * aggressive. + */ + to_reclaim = max(to_reclaim, delalloc_bytes >> 3); + items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2; } + trans = current->journal_info; + /* * If we are doing more ordered than delalloc we need to just wait on * ordered extents, otherwise we'll waste time trying to flush delalloc * that likely won't give us the space back we need. */ - if (dio_bytes > delalloc_bytes) + if (ordered_bytes > delalloc_bytes && !for_preempt) wait_ordered = true; loops = 0; - while ((delalloc_bytes || dio_bytes) && loops < 3) { - nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT; + while ((delalloc_bytes || ordered_bytes) && loops < 3) { + u64 temp = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT; + long nr_pages = min_t(u64, temp, LONG_MAX); + int async_pages; - /* - * Triggers inode writeback for up to nr_pages. This will invoke - * ->writepages callback and trigger delalloc filling - * (btrfs_run_delalloc_range()). - */ - btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items); + btrfs_start_delalloc_roots(fs_info, nr_pages, true); /* - * We need to wait for the compressed pages to start before - * we continue. + * We need to make sure any outstanding async pages are now + * processed before we continue. This is because things like + * sync_inode() try to be smart and skip writing if the inode is + * marked clean. We don't use filemap_fwrite for flushing + * because we want to control how many pages we write out at a + * time, thus this is the only safe way to make sure we've + * waited for outstanding compressed workers to have started + * their jobs and thus have ordered extents set up properly. + * + * This exists because we do not want to wait for each + * individual inode to finish its async work, we simply want to + * start the IO on everybody, and then come back here and wait + * for all of the async work to catch up. Once we're done with + * that we know we'll have ordered extents for everything and we + * can decide if we wait for that or not. + * + * If we choose to replace this in the future, make absolutely + * sure that the proper waiting is being done in the async case, + * as there have been bugs in that area before. */ async_pages = atomic_read(&fs_info->async_delalloc_pages); if (!async_pages) goto skip_async; /* - * Calculate how many compressed pages we want to be written - * before we continue. I.e if there are more async pages than we - * require wait_event will wait until nr_pages are written. + * We don't want to wait forever, if we wrote less pages in this + * loop than we have outstanding, only wait for that number of + * pages, otherwise we can wait for all async pages to finish + * before continuing. */ - if (async_pages <= nr_pages) - async_pages = 0; - else + if (async_pages > nr_pages) async_pages -= nr_pages; - + else + async_pages = 0; wait_event(fs_info->async_submit_wait, atomic_read(&fs_info->async_delalloc_pages) <= - (int)async_pages); + async_pages); skip_async: + loops++; + if (wait_ordered && !trans) { + btrfs_wait_ordered_roots(fs_info, items, NULL); + } else { + time_left = schedule_timeout_killable(1); + if (time_left) + break; + } + + /* + * If we are for preemption we just want a one-shot of delalloc + * flushing so we can stop flushing if we decide we don't need + * to anymore. + */ + if (for_preempt) + break; + spin_lock(&space_info->lock); if (list_empty(&space_info->tickets) && list_empty(&space_info->priority_tickets)) { @@ -596,130 +822,23 @@ skip_async: } spin_unlock(&space_info->lock); - loops++; - if (wait_ordered && !trans) { - btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); - } else { - time_left = schedule_timeout_killable(1); - if (time_left) - break; - } delalloc_bytes = percpu_counter_sum_positive( &fs_info->delalloc_bytes); - dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); + ordered_bytes = percpu_counter_sum_positive( + &fs_info->ordered_bytes); } } -/** - * maybe_commit_transaction - possibly commit the transaction if its ok to - * @root - the root we're allocating for - * @bytes - the number of bytes we want to reserve - * @force - force the commit - * - * This will check to make sure that committing the transaction will actually - * get us somewhere and then commit the transaction if it does. Otherwise it - * will return -ENOSPC. - */ -static int may_commit_transaction(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info) -{ - struct reserve_ticket *ticket = NULL; - struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv; - struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; - struct btrfs_block_rsv *trans_rsv = &fs_info->trans_block_rsv; - struct btrfs_trans_handle *trans; - u64 bytes_needed; - u64 reclaim_bytes = 0; - u64 cur_free_bytes = 0; - - trans = (struct btrfs_trans_handle *)current->journal_info; - if (trans) - return -EAGAIN; - - spin_lock(&space_info->lock); - cur_free_bytes = btrfs_space_info_used(space_info, true); - if (cur_free_bytes < space_info->total_bytes) - cur_free_bytes = space_info->total_bytes - cur_free_bytes; - else - cur_free_bytes = 0; - - if (!list_empty(&space_info->priority_tickets)) - ticket = list_first_entry(&space_info->priority_tickets, - struct reserve_ticket, list); - else if (!list_empty(&space_info->tickets)) - ticket = list_first_entry(&space_info->tickets, - struct reserve_ticket, list); - bytes_needed = (ticket) ? ticket->bytes : 0; - - if (bytes_needed > cur_free_bytes) - bytes_needed -= cur_free_bytes; - else - bytes_needed = 0; - spin_unlock(&space_info->lock); - - if (!bytes_needed) - return 0; - - trans = btrfs_join_transaction(fs_info->extent_root); - if (IS_ERR(trans)) - return PTR_ERR(trans); - - /* - * See if there is enough pinned space to make this reservation, or if - * we have block groups that are going to be freed, allowing us to - * possibly do a chunk allocation the next loop through. - */ - if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) || - __percpu_counter_compare(&space_info->total_bytes_pinned, - bytes_needed, - BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0) - goto commit; - - /* - * See if there is some space in the delayed insertion reservation for - * this reservation. - */ - if (space_info != delayed_rsv->space_info) - goto enospc; - - spin_lock(&delayed_rsv->lock); - reclaim_bytes += delayed_rsv->reserved; - spin_unlock(&delayed_rsv->lock); - - spin_lock(&delayed_refs_rsv->lock); - reclaim_bytes += delayed_refs_rsv->reserved; - spin_unlock(&delayed_refs_rsv->lock); - - spin_lock(&trans_rsv->lock); - reclaim_bytes += trans_rsv->reserved; - spin_unlock(&trans_rsv->lock); - - if (reclaim_bytes >= bytes_needed) - goto commit; - bytes_needed -= reclaim_bytes; - - if (__percpu_counter_compare(&space_info->total_bytes_pinned, - bytes_needed, - BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0) - goto enospc; - -commit: - return btrfs_commit_transaction(trans); -enospc: - btrfs_end_transaction(trans); - return -ENOSPC; -} - /* * Try to flush some data based on policy set by @state. This is only advisory * and may fail for various reasons. The caller is supposed to examine the * state of @space_info to detect the outcome. */ -static void flush_space(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, u64 num_bytes, - int state) +static void flush_space(struct btrfs_space_info *space_info, u64 num_bytes, + enum btrfs_flush_state state, bool for_preempt) { - struct btrfs_root *root = fs_info->extent_root; + struct btrfs_fs_info *fs_info = space_info->fs_info; + struct btrfs_root *root = fs_info->tree_root; struct btrfs_trans_handle *trans; int nr; int ret = 0; @@ -732,9 +851,11 @@ static void flush_space(struct btrfs_fs_info *fs_info, else nr = -1; - trans = btrfs_join_transaction(root); + trans = btrfs_join_transaction_nostart(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); + if (ret == -ENOENT) + ret = 0; break; } ret = btrfs_run_delayed_items_nr(trans, nr); @@ -742,21 +863,25 @@ static void flush_space(struct btrfs_fs_info *fs_info, break; case FLUSH_DELALLOC: case FLUSH_DELALLOC_WAIT: - shrink_delalloc(fs_info, num_bytes * 2, num_bytes, - state == FLUSH_DELALLOC_WAIT); + case FLUSH_DELALLOC_FULL: + if (state == FLUSH_DELALLOC_FULL) + num_bytes = U64_MAX; + shrink_delalloc(space_info, num_bytes, + state != FLUSH_DELALLOC, for_preempt); break; case FLUSH_DELAYED_REFS_NR: case FLUSH_DELAYED_REFS: - trans = btrfs_join_transaction(root); + trans = btrfs_join_transaction_nostart(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); + if (ret == -ENOENT) + ret = 0; break; } if (state == FLUSH_DELAYED_REFS_NR) - nr = calc_reclaim_items_nr(fs_info, num_bytes); + btrfs_run_delayed_refs(trans, num_bytes); else - nr = 0; - btrfs_run_delayed_refs(trans, nr); + btrfs_run_delayed_refs(trans, 0); btrfs_end_transaction(trans); break; case ALLOC_CHUNK: @@ -766,11 +891,12 @@ static void flush_space(struct btrfs_fs_info *fs_info, ret = PTR_ERR(trans); break; } - ret = btrfs_chunk_alloc(trans, - btrfs_metadata_alloc_profile(fs_info), + ret = btrfs_chunk_alloc(trans, space_info, + btrfs_get_alloc_profile(fs_info, space_info->flags), (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE : CHUNK_ALLOC_FORCE); btrfs_end_transaction(trans); + if (ret > 0 || ret == -ENOSPC) ret = 0; break; @@ -784,7 +910,18 @@ static void flush_space(struct btrfs_fs_info *fs_info, btrfs_wait_on_delayed_iputs(fs_info); break; case COMMIT_TRANS: - ret = may_commit_transaction(fs_info, space_info); + ASSERT(current->journal_info == NULL); + /* + * We don't want to start a new transaction, just attach to the + * current one or wait it fully commits in case its commit is + * happening at the moment. Note: we don't use a nostart join + * because that does not wait for a transaction to fully commit + * (only for it to be unblocked, state TRANS_STATE_UNBLOCKED). + */ + ret = btrfs_commit_current_transaction(root); + break; + case RESET_ZONES: + ret = btrfs_reset_unused_block_groups(space_info, num_bytes); break; default: ret = -ENOSPC; @@ -792,23 +929,19 @@ static void flush_space(struct btrfs_fs_info *fs_info, } trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state, - ret); + ret, for_preempt); return; } -static inline u64 -btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info) +static u64 btrfs_calc_reclaim_metadata_size(const struct btrfs_space_info *space_info) { u64 used; u64 avail; - u64 expected; u64 to_reclaim = space_info->reclaim_size; lockdep_assert_held(&space_info->lock); - avail = calc_available_free_space(fs_info, space_info, - BTRFS_RESERVE_FLUSH_ALL); + avail = calc_available_free_space(space_info, BTRFS_RESERVE_FLUSH_ALL); used = btrfs_space_info_used(space_info, true); /* @@ -820,79 +953,155 @@ btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, if (space_info->total_bytes + avail < used) to_reclaim += used - (space_info->total_bytes + avail); - if (to_reclaim) - return to_reclaim; - - to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M); - if (btrfs_can_overcommit(fs_info, space_info, to_reclaim, - BTRFS_RESERVE_FLUSH_ALL)) - return 0; - - used = btrfs_space_info_used(space_info, true); - - if (btrfs_can_overcommit(fs_info, space_info, SZ_1M, - BTRFS_RESERVE_FLUSH_ALL)) - expected = div_factor_fine(space_info->total_bytes, 95); - else - expected = div_factor_fine(space_info->total_bytes, 90); - - if (used > expected) - to_reclaim = used - expected; - else - to_reclaim = 0; - to_reclaim = min(to_reclaim, space_info->bytes_may_use + - space_info->bytes_reserved); return to_reclaim; } -static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, - u64 used) +static bool need_preemptive_reclaim(const struct btrfs_space_info *space_info) { - u64 thresh = div_factor_fine(space_info->total_bytes, 98); + struct btrfs_fs_info *fs_info = space_info->fs_info; + const u64 global_rsv_size = btrfs_block_rsv_reserved(&fs_info->global_block_rsv); + u64 ordered, delalloc; + u64 thresh; + u64 used; + + lockdep_assert_held(&space_info->lock); + + /* + * We have tickets queued, bail so we don't compete with the async + * flushers. + */ + if (space_info->reclaim_size) + return false; + + thresh = mult_perc(space_info->total_bytes, 90); /* If we're just plain full then async reclaim just slows us down. */ - if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh) - return 0; + if ((space_info->bytes_used + space_info->bytes_reserved + + global_rsv_size) >= thresh) + return false; - if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info)) - return 0; + used = space_info->bytes_may_use + space_info->bytes_pinned; + + /* The total flushable belongs to the global rsv, don't flush. */ + if (global_rsv_size >= used) + return false; + + /* + * 128MiB is 1/4 of the maximum global rsv size. If we have less than + * that devoted to other reservations then there's no sense in flushing, + * we don't have a lot of things that need flushing. + */ + if (used - global_rsv_size <= SZ_128M) + return false; + + /* + * If we have over half of the free space occupied by reservations or + * pinned then we want to start flushing. + * + * We do not do the traditional thing here, which is to say + * + * if (used >= ((total_bytes + avail) / 2)) + * return 1; + * + * because this doesn't quite work how we want. If we had more than 50% + * of the space_info used by bytes_used and we had 0 available we'd just + * constantly run the background flusher. Instead we want it to kick in + * if our reclaimable space exceeds our clamped free space. + * + * Our clamping range is 2^1 -> 2^8. Practically speaking that means + * the following: + * + * Amount of RAM Minimum threshold Maximum threshold + * + * 256GiB 1GiB 128GiB + * 128GiB 512MiB 64GiB + * 64GiB 256MiB 32GiB + * 32GiB 128MiB 16GiB + * 16GiB 64MiB 8GiB + * + * These are the range our thresholds will fall in, corresponding to how + * much delalloc we need for the background flusher to kick in. + */ + + thresh = calc_available_free_space(space_info, BTRFS_RESERVE_FLUSH_ALL); + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_readonly + global_rsv_size; + if (used < space_info->total_bytes) + thresh += space_info->total_bytes - used; + thresh >>= space_info->clamp; + + used = space_info->bytes_pinned; + + /* + * If we have more ordered bytes than delalloc bytes then we're either + * doing a lot of DIO, or we simply don't have a lot of delalloc waiting + * around. Preemptive flushing is only useful in that it can free up + * space before tickets need to wait for things to finish. In the case + * of ordered extents, preemptively waiting on ordered extents gets us + * nothing, if our reservations are tied up in ordered extents we'll + * simply have to slow down writers by forcing them to wait on ordered + * extents. + * + * In the case that ordered is larger than delalloc, only include the + * block reserves that we would actually be able to directly reclaim + * from. In this case if we're heavy on metadata operations this will + * clearly be heavy enough to warrant preemptive flushing. In the case + * of heavy DIO or ordered reservations, preemptive flushing will just + * waste time and cause us to slow down. + * + * We want to make sure we truly are maxed out on ordered however, so + * cut ordered in half, and if it's still higher than delalloc then we + * can keep flushing. This is to avoid the case where we start + * flushing, and now delalloc == ordered and we stop preemptively + * flushing when we could still have several gigs of delalloc to flush. + */ + ordered = percpu_counter_read_positive(&fs_info->ordered_bytes) >> 1; + delalloc = percpu_counter_read_positive(&fs_info->delalloc_bytes); + if (ordered >= delalloc) + used += btrfs_block_rsv_reserved(&fs_info->delayed_refs_rsv) + + btrfs_block_rsv_reserved(&fs_info->delayed_block_rsv); + else + used += space_info->bytes_may_use - global_rsv_size; return (used >= thresh && !btrfs_fs_closing(fs_info) && !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); } -static bool steal_from_global_rsv(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, +static bool steal_from_global_rsv(struct btrfs_space_info *space_info, struct reserve_ticket *ticket) { + struct btrfs_fs_info *fs_info = space_info->fs_info; struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; u64 min_bytes; + lockdep_assert_held(&space_info->lock); + + if (!ticket->steal) + return false; + if (global_rsv->space_info != space_info) return false; spin_lock(&global_rsv->lock); - min_bytes = div_factor(global_rsv->size, 1); + min_bytes = mult_perc(global_rsv->size, 10); if (global_rsv->reserved < min_bytes + ticket->bytes) { spin_unlock(&global_rsv->lock); return false; } global_rsv->reserved -= ticket->bytes; - ticket->bytes = 0; - list_del_init(&ticket->list); - wake_up(&ticket->wait); - space_info->tickets_id++; if (global_rsv->reserved < global_rsv->size) - global_rsv->full = 0; + global_rsv->full = false; spin_unlock(&global_rsv->lock); + remove_ticket(space_info, ticket, 0); + space_info->tickets_id++; + return true; } /* - * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets - * @fs_info - fs_info for this fs + * We've exhausted our flushing, start failing tickets. + * * @space_info - the space info we were flushing * * We call this when we've exhausted our flushing ability and haven't made @@ -905,82 +1114,66 @@ static bool steal_from_global_rsv(struct btrfs_fs_info *fs_info, * other tickets, or if it stumbles across a ticket that was smaller than the * first ticket. */ -static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info) +static bool maybe_fail_all_tickets(struct btrfs_space_info *space_info) { + struct btrfs_fs_info *fs_info = space_info->fs_info; struct reserve_ticket *ticket; u64 tickets_id = space_info->tickets_id; - u64 first_ticket_bytes = 0; + const int abort_error = BTRFS_FS_ERROR(fs_info); + + trace_btrfs_fail_all_tickets(fs_info, space_info); if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { btrfs_info(fs_info, "cannot satisfy tickets, dumping space info"); - __btrfs_dump_space_info(fs_info, space_info); + __btrfs_dump_space_info(space_info); } while (!list_empty(&space_info->tickets) && tickets_id == space_info->tickets_id) { ticket = list_first_entry(&space_info->tickets, struct reserve_ticket, list); + if (unlikely(abort_error)) { + remove_ticket(space_info, ticket, abort_error); + } else { + if (steal_from_global_rsv(space_info, ticket)) + return true; - if (ticket->steal && - steal_from_global_rsv(fs_info, space_info, ticket)) - return true; - - /* - * may_commit_transaction will avoid committing the transaction - * if it doesn't feel like the space reclaimed by the commit - * would result in the ticket succeeding. However if we have a - * smaller ticket in the queue it may be small enough to be - * satisified by committing the transaction, so if any - * subsequent ticket is smaller than the first ticket go ahead - * and send us back for another loop through the enospc flushing - * code. - */ - if (first_ticket_bytes == 0) - first_ticket_bytes = ticket->bytes; - else if (first_ticket_bytes > ticket->bytes) - return true; - - if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) - btrfs_info(fs_info, "failing ticket with %llu bytes", - ticket->bytes); + if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) + btrfs_info(fs_info, "failing ticket with %llu bytes", + ticket->bytes); - remove_ticket(space_info, ticket); - ticket->error = -ENOSPC; - wake_up(&ticket->wait); + remove_ticket(space_info, ticket, -ENOSPC); - /* - * We're just throwing tickets away, so more flushing may not - * trip over btrfs_try_granting_tickets, so we need to call it - * here to see if we can make progress with the next ticket in - * the list. - */ - btrfs_try_granting_tickets(fs_info, space_info); + /* + * We're just throwing tickets away, so more flushing may + * not trip over btrfs_try_granting_tickets, so we need + * to call it here to see if we can make progress with + * the next ticket in the list. + */ + btrfs_try_granting_tickets(space_info); + } } return (tickets_id != space_info->tickets_id); } -/* - * This is for normal flushers, we can wait all goddamned day if we want to. We - * will loop and continuously try to flush as long as we are making progress. - * We count progress as clearing off tickets each time we have to loop. - */ -static void btrfs_async_reclaim_metadata_space(struct work_struct *work) +static void do_async_reclaim_metadata_space(struct btrfs_space_info *space_info) { - struct btrfs_fs_info *fs_info; - struct btrfs_space_info *space_info; + struct btrfs_fs_info *fs_info = space_info->fs_info; u64 to_reclaim; - int flush_state; + enum btrfs_flush_state flush_state; int commit_cycles = 0; u64 last_tickets_id; + enum btrfs_flush_state final_state; - fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); - space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + if (btrfs_is_zoned(fs_info)) + final_state = RESET_ZONES; + else + final_state = COMMIT_TRANS; spin_lock(&space_info->lock); - to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); + to_reclaim = btrfs_calc_reclaim_metadata_size(space_info); if (!to_reclaim) { - space_info->flush = 0; + space_info->flush = false; spin_unlock(&space_info->lock); return; } @@ -989,15 +1182,14 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) flush_state = FLUSH_DELAYED_ITEMS_NR; do { - flush_space(fs_info, space_info, to_reclaim, flush_state); + flush_space(space_info, to_reclaim, flush_state, false); spin_lock(&space_info->lock); if (list_empty(&space_info->tickets)) { - space_info->flush = 0; + space_info->flush = false; spin_unlock(&space_info->lock); return; } - to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, - space_info); + to_reclaim = btrfs_calc_reclaim_metadata_size(space_info); if (last_tickets_id == space_info->tickets_id) { flush_state++; } else { @@ -1008,6 +1200,14 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) } /* + * We do not want to empty the system of delalloc unless we're + * under heavy pressure, so allow one trip through the flushing + * logic before we start doing a FLUSH_DELALLOC_FULL. + */ + if (flush_state == FLUSH_DELALLOC_FULL && !commit_cycles) + flush_state++; + + /* * We don't want to force a chunk allocation until we've tried * pretty hard to reclaim space. Think of the case where we * freed up a bunch of space and so have a lot of pinned space @@ -1020,31 +1220,286 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles) flush_state++; - if (flush_state > COMMIT_TRANS) { + if (flush_state > final_state) { commit_cycles++; if (commit_cycles > 2) { - if (maybe_fail_all_tickets(fs_info, space_info)) { + if (maybe_fail_all_tickets(space_info)) { flush_state = FLUSH_DELAYED_ITEMS_NR; commit_cycles--; } else { - space_info->flush = 0; + space_info->flush = false; } } else { flush_state = FLUSH_DELAYED_ITEMS_NR; } } spin_unlock(&space_info->lock); - } while (flush_state <= COMMIT_TRANS); + } while (flush_state <= final_state); } -void btrfs_init_async_reclaim_work(struct work_struct *work) +/* + * This is for normal flushers, it can wait as much time as needed. We will + * loop and continuously try to flush as long as we are making progress. We + * count progress as clearing off tickets each time we have to loop. + */ +static void btrfs_async_reclaim_metadata_space(struct work_struct *work) { - INIT_WORK(work, btrfs_async_reclaim_metadata_space); + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + + fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); + space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + do_async_reclaim_metadata_space(space_info); + for (int i = 0; i < BTRFS_SPACE_INFO_SUB_GROUP_MAX; i++) { + if (space_info->sub_group[i]) + do_async_reclaim_metadata_space(space_info->sub_group[i]); + } +} + +/* + * This handles pre-flushing of metadata space before we get to the point that + * we need to start blocking threads on tickets. The logic here is different + * from the other flush paths because it doesn't rely on tickets to tell us how + * much we need to flush, instead it attempts to keep us below the 80% full + * watermark of space by flushing whichever reservation pool is currently the + * largest. + */ +static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + struct btrfs_block_rsv *delayed_block_rsv; + struct btrfs_block_rsv *delayed_refs_rsv; + struct btrfs_block_rsv *global_rsv; + struct btrfs_block_rsv *trans_rsv; + int loops = 0; + + fs_info = container_of(work, struct btrfs_fs_info, + preempt_reclaim_work); + space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + delayed_block_rsv = &fs_info->delayed_block_rsv; + delayed_refs_rsv = &fs_info->delayed_refs_rsv; + global_rsv = &fs_info->global_block_rsv; + trans_rsv = &fs_info->trans_block_rsv; + + spin_lock(&space_info->lock); + while (need_preemptive_reclaim(space_info)) { + enum btrfs_flush_state flush; + u64 delalloc_size = 0; + u64 to_reclaim, block_rsv_size; + const u64 global_rsv_size = btrfs_block_rsv_reserved(global_rsv); + const u64 bytes_may_use = space_info->bytes_may_use; + const u64 bytes_pinned = space_info->bytes_pinned; + + spin_unlock(&space_info->lock); + /* + * We don't have a precise counter for the metadata being + * reserved for delalloc, so we'll approximate it by subtracting + * out the block rsv's space from the bytes_may_use. If that + * amount is higher than the individual reserves, then we can + * assume it's tied up in delalloc reservations. + */ + block_rsv_size = global_rsv_size + + btrfs_block_rsv_reserved(delayed_block_rsv) + + btrfs_block_rsv_reserved(delayed_refs_rsv) + + btrfs_block_rsv_reserved(trans_rsv); + if (block_rsv_size < bytes_may_use) + delalloc_size = bytes_may_use - block_rsv_size; + + /* + * We don't want to include the global_rsv in our calculation, + * because that's space we can't touch. Subtract it from the + * block_rsv_size for the next checks. + */ + block_rsv_size -= global_rsv_size; + + /* + * We really want to avoid flushing delalloc too much, as it + * could result in poor allocation patterns, so only flush it if + * it's larger than the rest of the pools combined. + */ + if (delalloc_size > block_rsv_size) { + to_reclaim = delalloc_size; + flush = FLUSH_DELALLOC; + } else if (bytes_pinned > + (btrfs_block_rsv_reserved(delayed_block_rsv) + + btrfs_block_rsv_reserved(delayed_refs_rsv))) { + to_reclaim = bytes_pinned; + flush = COMMIT_TRANS; + } else if (btrfs_block_rsv_reserved(delayed_block_rsv) > + btrfs_block_rsv_reserved(delayed_refs_rsv)) { + to_reclaim = btrfs_block_rsv_reserved(delayed_block_rsv); + flush = FLUSH_DELAYED_ITEMS_NR; + } else { + to_reclaim = btrfs_block_rsv_reserved(delayed_refs_rsv); + flush = FLUSH_DELAYED_REFS_NR; + } + + loops++; + + /* + * We don't want to reclaim everything, just a portion, so scale + * down the to_reclaim by 1/4. If it takes us down to 0, + * reclaim 1 items worth. + */ + to_reclaim >>= 2; + if (!to_reclaim) + to_reclaim = btrfs_calc_insert_metadata_size(fs_info, 1); + flush_space(space_info, to_reclaim, flush, true); + cond_resched(); + spin_lock(&space_info->lock); + } + + /* We only went through once, back off our clamping. */ + if (loops == 1 && !space_info->reclaim_size) + space_info->clamp = max(1, space_info->clamp - 1); + trace_btrfs_done_preemptive_reclaim(fs_info, space_info); + spin_unlock(&space_info->lock); +} + +/* + * FLUSH_DELALLOC_WAIT: + * Space is freed from flushing delalloc in one of two ways. + * + * 1) compression is on and we allocate less space than we reserved + * 2) we are overwriting existing space + * + * For #1 that extra space is reclaimed as soon as the delalloc pages are + * COWed, by way of btrfs_add_reserved_bytes() which adds the actual extent + * length to ->bytes_reserved, and subtracts the reserved space from + * ->bytes_may_use. + * + * For #2 this is trickier. Once the ordered extent runs we will drop the + * extent in the range we are overwriting, which creates a delayed ref for + * that freed extent. This however is not reclaimed until the transaction + * commits, thus the next stages. + * + * RUN_DELAYED_IPUTS + * If we are freeing inodes, we want to make sure all delayed iputs have + * completed, because they could have been on an inode with i_nlink == 0, and + * thus have been truncated and freed up space. But again this space is not + * immediately reusable, it comes in the form of a delayed ref, which must be + * run and then the transaction must be committed. + * + * COMMIT_TRANS + * This is where we reclaim all of the pinned space generated by running the + * iputs + * + * RESET_ZONES + * This state works only for the zoned mode. We scan the unused block group + * list and reset the zones and reuse the block group. + * + * ALLOC_CHUNK_FORCE + * For data we start with alloc chunk force, however we could have been full + * before, and then the transaction commit could have freed new block groups, + * so if we now have space to allocate do the force chunk allocation. + */ +static const enum btrfs_flush_state data_flush_states[] = { + FLUSH_DELALLOC_FULL, + RUN_DELAYED_IPUTS, + COMMIT_TRANS, + RESET_ZONES, + ALLOC_CHUNK_FORCE, +}; + +static void do_async_reclaim_data_space(struct btrfs_space_info *space_info) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + u64 last_tickets_id; + enum btrfs_flush_state flush_state = 0; + + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = false; + spin_unlock(&space_info->lock); + return; + } + last_tickets_id = space_info->tickets_id; + spin_unlock(&space_info->lock); + + while (!space_info->full) { + flush_space(space_info, U64_MAX, ALLOC_CHUNK_FORCE, false); + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = false; + spin_unlock(&space_info->lock); + return; + } + + /* Something happened, fail everything and bail. */ + if (unlikely(BTRFS_FS_ERROR(fs_info))) + goto aborted_fs; + last_tickets_id = space_info->tickets_id; + spin_unlock(&space_info->lock); + } + + while (flush_state < ARRAY_SIZE(data_flush_states)) { + flush_space(space_info, U64_MAX, + data_flush_states[flush_state], false); + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = false; + spin_unlock(&space_info->lock); + return; + } + + if (last_tickets_id == space_info->tickets_id) { + flush_state++; + } else { + last_tickets_id = space_info->tickets_id; + flush_state = 0; + } + + if (flush_state >= ARRAY_SIZE(data_flush_states)) { + if (space_info->full) { + if (maybe_fail_all_tickets(space_info)) + flush_state = 0; + else + space_info->flush = false; + } else { + flush_state = 0; + } + + /* Something happened, fail everything and bail. */ + if (unlikely(BTRFS_FS_ERROR(fs_info))) + goto aborted_fs; + + } + spin_unlock(&space_info->lock); + } + return; + +aborted_fs: + maybe_fail_all_tickets(space_info); + space_info->flush = false; + spin_unlock(&space_info->lock); +} + +static void btrfs_async_reclaim_data_space(struct work_struct *work) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + + fs_info = container_of(work, struct btrfs_fs_info, async_data_reclaim_work); + space_info = fs_info->data_sinfo; + do_async_reclaim_data_space(space_info); + for (int i = 0; i < BTRFS_SPACE_INFO_SUB_GROUP_MAX; i++) + if (space_info->sub_group[i]) + do_async_reclaim_data_space(space_info->sub_group[i]); +} + +void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info) +{ + INIT_WORK(&fs_info->async_reclaim_work, btrfs_async_reclaim_metadata_space); + INIT_WORK(&fs_info->async_data_reclaim_work, btrfs_async_reclaim_data_space); + INIT_WORK(&fs_info->preempt_reclaim_work, + btrfs_preempt_reclaim_metadata_space); } static const enum btrfs_flush_state priority_flush_states[] = { FLUSH_DELAYED_ITEMS_NR, FLUSH_DELAYED_ITEMS, + RESET_ZONES, ALLOC_CHUNK, }; @@ -1055,51 +1510,108 @@ static const enum btrfs_flush_state evict_flush_states[] = { FLUSH_DELAYED_REFS, FLUSH_DELALLOC, FLUSH_DELALLOC_WAIT, + FLUSH_DELALLOC_FULL, ALLOC_CHUNK, COMMIT_TRANS, + RESET_ZONES, }; -static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, - struct reserve_ticket *ticket, - const enum btrfs_flush_state *states, - int states_nr) +static bool is_ticket_served(struct reserve_ticket *ticket) +{ + bool ret; + + spin_lock(&ticket->lock); + ret = (ticket->bytes == 0); + spin_unlock(&ticket->lock); + + return ret; +} + +static void priority_reclaim_metadata_space(struct btrfs_space_info *space_info, + struct reserve_ticket *ticket, + const enum btrfs_flush_state *states, + int states_nr) { + struct btrfs_fs_info *fs_info = space_info->fs_info; u64 to_reclaim; - int flush_state; + int flush_state = 0; - spin_lock(&space_info->lock); - to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); - if (!to_reclaim) { - spin_unlock(&space_info->lock); + /* + * This is the priority reclaim path, so to_reclaim could be >0 still + * because we may have only satisfied the priority tickets and still + * left non priority tickets on the list. We would then have + * to_reclaim but ->bytes == 0. + */ + if (is_ticket_served(ticket)) return; - } + + spin_lock(&space_info->lock); + to_reclaim = btrfs_calc_reclaim_metadata_size(space_info); spin_unlock(&space_info->lock); - flush_state = 0; - do { - flush_space(fs_info, space_info, to_reclaim, states[flush_state]); - flush_state++; - spin_lock(&space_info->lock); - if (ticket->bytes == 0) { - spin_unlock(&space_info->lock); + while (flush_state < states_nr) { + flush_space(space_info, to_reclaim, states[flush_state], false); + if (is_ticket_served(ticket)) return; - } + flush_state++; + } + + spin_lock(&space_info->lock); + /* + * Attempt to steal from the global rsv if we can, except if the fs was + * turned into error mode due to a transaction abort when flushing space + * above, in that case fail with the abort error instead of returning + * success to the caller if we can steal from the global rsv - this is + * just to have caller fail immediately instead of later when trying to + * modify the fs, making it easier to debug -ENOSPC problems. + */ + if (unlikely(BTRFS_FS_ERROR(fs_info))) + remove_ticket(space_info, ticket, BTRFS_FS_ERROR(fs_info)); + else if (!steal_from_global_rsv(space_info, ticket)) + remove_ticket(space_info, ticket, -ENOSPC); + + /* + * We must run try_granting_tickets here because we could be a large + * ticket in front of a smaller ticket that can now be satisfied with + * the available space. + */ + btrfs_try_granting_tickets(space_info); + spin_unlock(&space_info->lock); +} + +static void priority_reclaim_data_space(struct btrfs_space_info *space_info, + struct reserve_ticket *ticket) +{ + /* We could have been granted before we got here. */ + if (is_ticket_served(ticket)) + return; + + spin_lock(&space_info->lock); + while (!space_info->full) { spin_unlock(&space_info->lock); - } while (flush_state < states_nr); + flush_space(space_info, U64_MAX, ALLOC_CHUNK_FORCE, false); + if (is_ticket_served(ticket)) + return; + spin_lock(&space_info->lock); + } + + remove_ticket(space_info, ticket, -ENOSPC); + btrfs_try_granting_tickets(space_info); + spin_unlock(&space_info->lock); } -static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, +static void wait_reserve_ticket(struct btrfs_space_info *space_info, struct reserve_ticket *ticket) { DEFINE_WAIT(wait); - int ret = 0; - spin_lock(&space_info->lock); + spin_lock(&ticket->lock); while (ticket->bytes > 0 && ticket->error == 0) { + int ret; + ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE); + spin_unlock(&ticket->lock); if (ret) { /* * Delete us from the list. After we unlock the space @@ -1109,76 +1621,64 @@ static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, * despite getting an error, resulting in a space leak * (bytes_may_use counter of our space_info). */ - remove_ticket(space_info, ticket); - ticket->error = -EINTR; - break; + spin_lock(&space_info->lock); + remove_ticket(space_info, ticket, -EINTR); + spin_unlock(&space_info->lock); + return; } - spin_unlock(&space_info->lock); schedule(); finish_wait(&ticket->wait, &wait); - spin_lock(&space_info->lock); + spin_lock(&ticket->lock); } - spin_unlock(&space_info->lock); + spin_unlock(&ticket->lock); } -/** - * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket - * @fs_info - the fs - * @space_info - the space_info for the reservation - * @ticket - the ticket for the reservation - * @flush - how much we can flush +/* + * Do the appropriate flushing and waiting for a ticket. + * + * @space_info: space info for the reservation + * @ticket: ticket for the reservation + * @start_ns: timestamp when the reservation started + * @orig_bytes: amount of bytes originally reserved + * @flush: how much we can flush * * This does the work of figuring out how to flush for the ticket, waiting for * the reservation, and returning the appropriate error if there is one. */ -static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, +static int handle_reserve_ticket(struct btrfs_space_info *space_info, struct reserve_ticket *ticket, + u64 start_ns, u64 orig_bytes, enum btrfs_reserve_flush_enum flush) { int ret; switch (flush) { + case BTRFS_RESERVE_FLUSH_DATA: case BTRFS_RESERVE_FLUSH_ALL: case BTRFS_RESERVE_FLUSH_ALL_STEAL: - wait_reserve_ticket(fs_info, space_info, ticket); + wait_reserve_ticket(space_info, ticket); break; case BTRFS_RESERVE_FLUSH_LIMIT: - priority_reclaim_metadata_space(fs_info, space_info, ticket, + priority_reclaim_metadata_space(space_info, ticket, priority_flush_states, ARRAY_SIZE(priority_flush_states)); break; case BTRFS_RESERVE_FLUSH_EVICT: - priority_reclaim_metadata_space(fs_info, space_info, ticket, + priority_reclaim_metadata_space(space_info, ticket, evict_flush_states, ARRAY_SIZE(evict_flush_states)); break; + case BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE: + priority_reclaim_data_space(space_info, ticket); + break; default: - ASSERT(0); + ASSERT(0, "flush=%d", flush); break; } - spin_lock(&space_info->lock); ret = ticket->error; - if (ticket->bytes || ticket->error) { - /* - * We were a priority ticket, so we need to delete ourselves - * from the list. Because we could have other priority tickets - * behind us that require less space, run - * btrfs_try_granting_tickets() to see if their reservations can - * now be made. - */ - if (!list_empty(&ticket->list)) { - remove_ticket(space_info, ticket); - btrfs_try_granting_tickets(fs_info, space_info); - } - - if (!ret) - ret = -ENOSPC; - } - spin_unlock(&space_info->lock); ASSERT(list_empty(&ticket->list)); /* * Check that we can't have an error set if the reservation succeeded, @@ -1186,7 +1686,10 @@ static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, * releasing reserved space (if an error happens the expectation is that * space wasn't reserved at all). */ - ASSERT(!(ticket->bytes == 0 && ticket->error)); + ASSERT(!(ticket->bytes == 0 && ticket->error), + "ticket->bytes=%llu ticket->error=%d", ticket->bytes, ticket->error); + trace_btrfs_reserve_ticket(space_info->fs_info, space_info->flags, + orig_bytes, start_ns, flush, ticket->error); return ret; } @@ -1200,12 +1703,46 @@ static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush) (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL); } -/** - * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space - * @root - the root we're allocating for - * @space_info - the space info we want to allocate from - * @orig_bytes - the number of bytes we want - * @flush - whether or not we can flush to make our reservation +static inline void maybe_clamp_preempt(struct btrfs_space_info *space_info) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + u64 ordered = percpu_counter_sum_positive(&fs_info->ordered_bytes); + u64 delalloc = percpu_counter_sum_positive(&fs_info->delalloc_bytes); + + /* + * If we're heavy on ordered operations then clamping won't help us. We + * need to clamp specifically to keep up with dirty'ing buffered + * writers, because there's not a 1:1 correlation of writing delalloc + * and freeing space, like there is with flushing delayed refs or + * delayed nodes. If we're already more ordered than delalloc then + * we're keeping up, otherwise we aren't and should probably clamp. + */ + if (ordered < delalloc) + space_info->clamp = min(space_info->clamp + 1, 8); +} + +static inline bool can_steal(enum btrfs_reserve_flush_enum flush) +{ + return (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL || + flush == BTRFS_RESERVE_FLUSH_EVICT); +} + +/* + * NO_FLUSH and FLUSH_EMERGENCY don't want to create a ticket, they just want to + * fail as quickly as possible. + */ +static inline bool can_ticket(enum btrfs_reserve_flush_enum flush) +{ + return (flush != BTRFS_RESERVE_NO_FLUSH && + flush != BTRFS_RESERVE_FLUSH_EMERGENCY); +} + +/* + * Try to reserve bytes from the block_rsv's space. + * + * @space_info: space info we want to allocate from + * @orig_bytes: number of bytes we want + * @flush: whether or not we can flush to make our reservation * * This will reserve orig_bytes number of bytes from the space info associated * with the block_rsv. If there is not enough space it will make an attempt to @@ -1214,21 +1751,37 @@ static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush) * regain reservations will be made and this will fail if there is not enough * space already. */ -static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, - struct btrfs_space_info *space_info, - u64 orig_bytes, - enum btrfs_reserve_flush_enum flush) +static int reserve_bytes(struct btrfs_space_info *space_info, u64 orig_bytes, + enum btrfs_reserve_flush_enum flush) { + struct btrfs_fs_info *fs_info = space_info->fs_info; + struct work_struct *async_work; struct reserve_ticket ticket; + u64 start_ns = 0; u64 used; - int ret = 0; + int ret = -ENOSPC; bool pending_tickets; - ASSERT(orig_bytes); - ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL); + ASSERT(orig_bytes, "orig_bytes=%llu", orig_bytes); + /* + * If have a transaction handle (current->journal_info != NULL), then + * the flush method can not be neither BTRFS_RESERVE_FLUSH_ALL* nor + * BTRFS_RESERVE_FLUSH_EVICT, as we could deadlock because those + * flushing methods can trigger transaction commits. + */ + if (current->journal_info) { + /* One assert per line for easier debugging. */ + ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL, "flush=%d", flush); + ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL_STEAL, "flush=%d", flush); + ASSERT(flush != BTRFS_RESERVE_FLUSH_EVICT, "flush=%d", flush); + } + + if (flush == BTRFS_RESERVE_FLUSH_DATA) + async_work = &fs_info->async_data_reclaim_work; + else + async_work = &fs_info->async_reclaim_work; spin_lock(&space_info->lock); - ret = -ENOSPC; used = btrfs_space_info_used(space_info, true); /* @@ -1248,70 +1801,94 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, */ if (!pending_tickets && ((used + orig_bytes <= space_info->total_bytes) || - btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) { - btrfs_space_info_update_bytes_may_use(fs_info, space_info, - orig_bytes); + can_overcommit(space_info, used, orig_bytes, flush))) { + btrfs_space_info_update_bytes_may_use(space_info, orig_bytes); ret = 0; } /* + * Things are dire, we need to make a reservation so we don't abort. We + * will let this reservation go through as long as we have actual space + * left to allocate for the block. + */ + if (ret && unlikely(flush == BTRFS_RESERVE_FLUSH_EMERGENCY)) { + used -= space_info->bytes_may_use; + if (used + orig_bytes <= space_info->total_bytes) { + btrfs_space_info_update_bytes_may_use(space_info, orig_bytes); + ret = 0; + } + } + + /* * If we couldn't make a reservation then setup our reservation ticket * and kick the async worker if it's not already running. * * If we are a priority flusher then we just need to add our ticket to * the list and we will do our own flushing further down. */ - if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { + if (ret && can_ticket(flush)) { ticket.bytes = orig_bytes; ticket.error = 0; space_info->reclaim_size += ticket.bytes; init_waitqueue_head(&ticket.wait); - ticket.steal = (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL); + spin_lock_init(&ticket.lock); + ticket.steal = can_steal(flush); + if (trace_btrfs_reserve_ticket_enabled()) + start_ns = ktime_get_ns(); + if (flush == BTRFS_RESERVE_FLUSH_ALL || - flush == BTRFS_RESERVE_FLUSH_ALL_STEAL) { + flush == BTRFS_RESERVE_FLUSH_ALL_STEAL || + flush == BTRFS_RESERVE_FLUSH_DATA) { list_add_tail(&ticket.list, &space_info->tickets); if (!space_info->flush) { - space_info->flush = 1; + /* + * We were forced to add a reserve ticket, so + * our preemptive flushing is unable to keep + * up. Clamp down on the threshold for the + * preemptive flushing in order to keep up with + * the workload. + */ + maybe_clamp_preempt(space_info); + + space_info->flush = true; trace_btrfs_trigger_flush(fs_info, space_info->flags, orig_bytes, flush, "enospc"); - queue_work(system_unbound_wq, - &fs_info->async_reclaim_work); + queue_work(system_dfl_wq, async_work); } } else { list_add_tail(&ticket.list, &space_info->priority_tickets); } } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { - used += orig_bytes; /* * We will do the space reservation dance during log replay, * which means we won't have fs_info->fs_root set, so don't do * the async reclaim as we will panic. */ if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) && - need_do_async_reclaim(fs_info, space_info, used) && - !work_busy(&fs_info->async_reclaim_work)) { + !work_busy(&fs_info->preempt_reclaim_work) && + need_preemptive_reclaim(space_info)) { trace_btrfs_trigger_flush(fs_info, space_info->flags, orig_bytes, flush, "preempt"); - queue_work(system_unbound_wq, - &fs_info->async_reclaim_work); + queue_work(system_dfl_wq, + &fs_info->preempt_reclaim_work); } } spin_unlock(&space_info->lock); - if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) + if (!ret || !can_ticket(flush)) return ret; - return handle_reserve_ticket(fs_info, space_info, &ticket, flush); + return handle_reserve_ticket(space_info, &ticket, start_ns, orig_bytes, flush); } -/** - * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space - * @root - the root we're allocating for - * @block_rsv - the block_rsv we're allocating for - * @orig_bytes - the number of bytes we want - * @flush - whether or not we can flush to make our reservation +/* + * Try to reserve metadata bytes from the block_rsv's space. + * + * @space_info: the space_info we're allocating for + * @orig_bytes: number of bytes we want + * @flush: whether or not we can flush to make our reservation * * This will reserve orig_bytes number of bytes from the space info associated * with the block_rsv. If there is not enough space it will make an attempt to @@ -1320,31 +1897,329 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, * regain reservations will be made and this will fail if there is not enough * space already. */ -int btrfs_reserve_metadata_bytes(struct btrfs_root *root, - struct btrfs_block_rsv *block_rsv, +int btrfs_reserve_metadata_bytes(struct btrfs_space_info *space_info, u64 orig_bytes, enum btrfs_reserve_flush_enum flush) { - struct btrfs_fs_info *fs_info = root->fs_info; - struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; int ret; - ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info, - orig_bytes, flush); - if (ret == -ENOSPC && - unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) { - if (block_rsv != global_rsv && - !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes)) - ret = 0; - } + ret = reserve_bytes(space_info, orig_bytes, flush); if (ret == -ENOSPC) { + struct btrfs_fs_info *fs_info = space_info->fs_info; + trace_btrfs_space_reservation(fs_info, "space_info:enospc", - block_rsv->space_info->flags, - orig_bytes, 1); + space_info->flags, orig_bytes, 1); if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) - btrfs_dump_space_info(fs_info, block_rsv->space_info, - orig_bytes, 0); + btrfs_dump_space_info(space_info, orig_bytes, false); } return ret; } + +/* + * Try to reserve data bytes for an allocation. + * + * @space_info: the space_info we're allocating for + * @bytes: number of bytes we need + * @flush: how we are allowed to flush + * + * This will reserve bytes from the data space info. If there is not enough + * space then we will attempt to flush space as specified by flush. + */ +int btrfs_reserve_data_bytes(struct btrfs_space_info *space_info, u64 bytes, + enum btrfs_reserve_flush_enum flush) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + int ret; + + ASSERT(flush == BTRFS_RESERVE_FLUSH_DATA || + flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE || + flush == BTRFS_RESERVE_NO_FLUSH, "flush=%d", flush); + ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_DATA, + "current->journal_info=0x%lx flush=%d", + (unsigned long)current->journal_info, flush); + + ret = reserve_bytes(space_info, bytes, flush); + if (ret == -ENOSPC) { + trace_btrfs_space_reservation(fs_info, "space_info:enospc", + space_info->flags, bytes, 1); + if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) + btrfs_dump_space_info(space_info, bytes, false); + } + return ret; +} + +/* Dump all the space infos when we abort a transaction due to ENOSPC. */ +__cold void btrfs_dump_space_info_for_trans_abort(struct btrfs_fs_info *fs_info) +{ + struct btrfs_space_info *space_info; + + btrfs_info(fs_info, "dumping space info:"); + list_for_each_entry(space_info, &fs_info->space_info, list) { + spin_lock(&space_info->lock); + __btrfs_dump_space_info(space_info); + spin_unlock(&space_info->lock); + } + dump_global_block_rsv(fs_info); +} + +/* + * Account the unused space of all the readonly block group in the space_info. + * takes mirrors into account. + */ +u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo) +{ + struct btrfs_block_group *block_group; + u64 free_bytes = 0; + int factor; + + /* It's df, we don't care if it's racy */ + if (data_race(list_empty(&sinfo->ro_bgs))) + return 0; + + spin_lock(&sinfo->lock); + list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) { + spin_lock(&block_group->lock); + + if (!block_group->ro) { + spin_unlock(&block_group->lock); + continue; + } + + factor = btrfs_bg_type_to_factor(block_group->flags); + free_bytes += (block_group->length - + block_group->used) * factor; + + spin_unlock(&block_group->lock); + } + spin_unlock(&sinfo->lock); + + return free_bytes; +} + +static u64 calc_pct_ratio(u64 x, u64 y) +{ + int ret; + + if (!y) + return 0; +again: + ret = check_mul_overflow(100, x, &x); + if (ret) + goto lose_precision; + return div64_u64(x, y); +lose_precision: + x >>= 10; + y >>= 10; + if (!y) + y = 1; + goto again; +} + +/* + * A reasonable buffer for unallocated space is 10 data block_groups. + * If we claw this back repeatedly, we can still achieve efficient + * utilization when near full, and not do too much reclaim while + * always maintaining a solid buffer for workloads that quickly + * allocate and pressure the unallocated space. + */ +static u64 calc_unalloc_target(struct btrfs_fs_info *fs_info) +{ + u64 chunk_sz = calc_effective_data_chunk_size(fs_info); + + return BTRFS_UNALLOC_BLOCK_GROUP_TARGET * chunk_sz; +} + +/* + * The fundamental goal of automatic reclaim is to protect the filesystem's + * unallocated space and thus minimize the probability of the filesystem going + * read only when a metadata allocation failure causes a transaction abort. + * + * However, relocations happen into the space_info's unused space, therefore + * automatic reclaim must also back off as that space runs low. There is no + * value in doing trivial "relocations" of re-writing the same block group + * into a fresh one. + * + * Furthermore, we want to avoid doing too much reclaim even if there are good + * candidates. This is because the allocator is pretty good at filling up the + * holes with writes. So we want to do just enough reclaim to try and stay + * safe from running out of unallocated space but not be wasteful about it. + * + * Therefore, the dynamic reclaim threshold is calculated as follows: + * - calculate a target unallocated amount of 5 block group sized chunks + * - ratchet up the intensity of reclaim depending on how far we are from + * that target by using a formula of unalloc / target to set the threshold. + * + * Typically with 10 block groups as the target, the discrete values this comes + * out to are 0, 10, 20, ... , 80, 90, and 99. + */ +static int calc_dynamic_reclaim_threshold(const struct btrfs_space_info *space_info) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + u64 unalloc = atomic64_read(&fs_info->free_chunk_space); + u64 target = calc_unalloc_target(fs_info); + u64 alloc = space_info->total_bytes; + u64 used = btrfs_space_info_used(space_info, false); + u64 unused = alloc - used; + u64 want = target > unalloc ? target - unalloc : 0; + u64 data_chunk_size = calc_effective_data_chunk_size(fs_info); + + /* If we have no unused space, don't bother, it won't work anyway. */ + if (unused < data_chunk_size) + return 0; + + /* Cast to int is OK because want <= target. */ + return calc_pct_ratio(want, target); +} + +int btrfs_calc_reclaim_threshold(const struct btrfs_space_info *space_info) +{ + lockdep_assert_held(&space_info->lock); + + if (READ_ONCE(space_info->dynamic_reclaim)) + return calc_dynamic_reclaim_threshold(space_info); + return READ_ONCE(space_info->bg_reclaim_threshold); +} + +/* + * Under "urgent" reclaim, we will reclaim even fresh block groups that have + * recently seen successful allocations, as we are desperate to reclaim + * whatever we can to avoid ENOSPC in a transaction leading to a readonly fs. + */ +static bool is_reclaim_urgent(struct btrfs_space_info *space_info) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + u64 unalloc = atomic64_read(&fs_info->free_chunk_space); + u64 data_chunk_size = calc_effective_data_chunk_size(fs_info); + + return unalloc < data_chunk_size; +} + +static void do_reclaim_sweep(struct btrfs_space_info *space_info, int raid) +{ + struct btrfs_block_group *bg; + int thresh_pct; + bool try_again = true; + bool urgent; + + spin_lock(&space_info->lock); + urgent = is_reclaim_urgent(space_info); + thresh_pct = btrfs_calc_reclaim_threshold(space_info); + spin_unlock(&space_info->lock); + + down_read(&space_info->groups_sem); +again: + list_for_each_entry(bg, &space_info->block_groups[raid], list) { + u64 thresh; + bool reclaim = false; + + btrfs_get_block_group(bg); + spin_lock(&bg->lock); + thresh = mult_perc(bg->length, thresh_pct); + if (bg->used < thresh && bg->reclaim_mark) { + try_again = false; + reclaim = true; + } + bg->reclaim_mark++; + spin_unlock(&bg->lock); + if (reclaim) + btrfs_mark_bg_to_reclaim(bg); + btrfs_put_block_group(bg); + } + + /* + * In situations where we are very motivated to reclaim (low unalloc) + * use two passes to make the reclaim mark check best effort. + * + * If we have any staler groups, we don't touch the fresher ones, but if we + * really need a block group, do take a fresh one. + */ + if (try_again && urgent) { + try_again = false; + goto again; + } + + up_read(&space_info->groups_sem); +} + +void btrfs_space_info_update_reclaimable(struct btrfs_space_info *space_info, s64 bytes) +{ + u64 chunk_sz = calc_effective_data_chunk_size(space_info->fs_info); + + lockdep_assert_held(&space_info->lock); + space_info->reclaimable_bytes += bytes; + + if (space_info->reclaimable_bytes >= chunk_sz) + btrfs_set_periodic_reclaim_ready(space_info, true); +} + +void btrfs_set_periodic_reclaim_ready(struct btrfs_space_info *space_info, bool ready) +{ + lockdep_assert_held(&space_info->lock); + if (!READ_ONCE(space_info->periodic_reclaim)) + return; + if (ready != space_info->periodic_reclaim_ready) { + space_info->periodic_reclaim_ready = ready; + if (!ready) + space_info->reclaimable_bytes = 0; + } +} + +static bool btrfs_should_periodic_reclaim(struct btrfs_space_info *space_info) +{ + bool ret; + + if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) + return false; + if (!READ_ONCE(space_info->periodic_reclaim)) + return false; + + spin_lock(&space_info->lock); + ret = space_info->periodic_reclaim_ready; + btrfs_set_periodic_reclaim_ready(space_info, false); + spin_unlock(&space_info->lock); + + return ret; +} + +void btrfs_reclaim_sweep(const struct btrfs_fs_info *fs_info) +{ + int raid; + struct btrfs_space_info *space_info; + + list_for_each_entry(space_info, &fs_info->space_info, list) { + if (!btrfs_should_periodic_reclaim(space_info)) + continue; + for (raid = 0; raid < BTRFS_NR_RAID_TYPES; raid++) + do_reclaim_sweep(space_info, raid); + } +} + +void btrfs_return_free_space(struct btrfs_space_info *space_info, u64 len) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + + lockdep_assert_held(&space_info->lock); + + /* Prioritize the global reservation to receive the freed space. */ + if (global_rsv->space_info != space_info) + goto grant; + + spin_lock(&global_rsv->lock); + if (!global_rsv->full) { + u64 to_add = min(len, global_rsv->size - global_rsv->reserved); + + global_rsv->reserved += to_add; + btrfs_space_info_update_bytes_may_use(space_info, to_add); + if (global_rsv->reserved >= global_rsv->size) + global_rsv->full = true; + len -= to_add; + } + spin_unlock(&global_rsv->lock); + +grant: + /* Add to any tickets we may have. */ + if (len) + btrfs_try_granting_tickets(space_info); +} |