diff options
Diffstat (limited to 'fs/btrfs/space-info.c')
| -rw-r--r-- | fs/btrfs/space-info.c | 1390 |
1 files changed, 1037 insertions, 353 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 01297c5b2666..f171bf875633 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -9,6 +9,155 @@ #include "ordered-data.h" #include "transaction.h" #include "block-group.h" +#include "zoned.h" + +/* + * HOW DOES SPACE RESERVATION WORK + * + * If you want to know about delalloc specifically, there is a separate comment + * for that with the delalloc code. This comment is about how the whole system + * works generally. + * + * BASIC CONCEPTS + * + * 1) space_info. This is the ultimate arbiter of how much space we can use. + * There's a description of the bytes_ fields with the struct declaration, + * refer to that for specifics on each field. Suffice it to say that for + * reservations we care about total_bytes - SUM(space_info->bytes_) when + * determining if there is space to make an allocation. There is a space_info + * for METADATA, SYSTEM, and DATA areas. + * + * 2) block_rsv's. These are basically buckets for every different type of + * metadata reservation we have. You can see the comment in the block_rsv + * code on the rules for each type, but generally block_rsv->reserved is how + * much space is accounted for in space_info->bytes_may_use. + * + * 3) btrfs_calc*_size. These are the worst case calculations we used based + * on the number of items we will want to modify. We have one for changing + * items, and one for inserting new items. Generally we use these helpers to + * determine the size of the block reserves, and then use the actual bytes + * values to adjust the space_info counters. + * + * MAKING RESERVATIONS, THE NORMAL CASE + * + * We call into either btrfs_reserve_data_bytes() or + * btrfs_reserve_metadata_bytes(), depending on which we're looking for, with + * num_bytes we want to reserve. + * + * ->reserve + * space_info->bytes_may_reserve += num_bytes + * + * ->extent allocation + * Call btrfs_add_reserved_bytes() which does + * space_info->bytes_may_reserve -= num_bytes + * space_info->bytes_reserved += extent_bytes + * + * ->insert reference + * Call btrfs_update_block_group() which does + * space_info->bytes_reserved -= extent_bytes + * space_info->bytes_used += extent_bytes + * + * MAKING RESERVATIONS, FLUSHING NORMALLY (non-priority) + * + * Assume we are unable to simply make the reservation because we do not have + * enough space + * + * -> __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 + * + * ->handle_reserve_ticket + * wait on ticket->wait for ->bytes to be reduced to 0, or ->error to be set + * on the ticket. + * + * -> btrfs_async_reclaim_metadata_space/btrfs_async_reclaim_data_space + * Flushes various things attempting to free up space. + * + * -> btrfs_try_granting_tickets() + * This is called by anything that either subtracts space from + * space_info->bytes_may_use, ->bytes_pinned, etc, or adds to the + * space_info->total_bytes. This loops through the ->priority_tickets and + * then the ->tickets list checking to see if the reservation can be + * completed. If it can the space is added to space_info->bytes_may_use and + * the ticket is woken up. + * + * -> ticket wakeup + * Check if ->bytes == 0, if it does we got our reservation and we can carry + * on, if not return the appropriate error (ENOSPC, but can be EINTR if we + * were interrupted.) + * + * MAKING RESERVATIONS, FLUSHING HIGH PRIORITY + * + * Same as the above, except we add ourselves to the + * space_info->priority_tickets, and we do not use ticket->wait, we simply + * call flush_space() ourselves for the states that are safe for us to call + * without deadlocking and hope for the best. + * + * THE FLUSHING STATES + * + * Generally speaking we will have two cases for each state, a "nice" state + * and a "ALL THE THINGS" state. In btrfs we delay a lot of work in order to + * reduce the locking over head on the various trees, and even to keep from + * doing any work at all in the case of delayed refs. Each of these delayed + * things however hold reservations, and so letting them run allows us to + * reclaim space so we can make new reservations. + * + * FLUSH_DELAYED_ITEMS + * Every inode has a delayed item to update the inode. Take a simple write + * for example, we would update the inode item at write time to update the + * mtime, and then again at finish_ordered_io() time in order to update the + * isize or bytes. We keep these delayed items to coalesce these operations + * into a single operation done on demand. These are an easy way to reclaim + * metadata space. + * + * FLUSH_DELALLOC + * Look at the delalloc comment to get an idea of how much space is reserved + * for delayed allocation. We can reclaim some of this space simply by + * running delalloc, but usually we need to wait for ordered extents to + * reclaim the bulk of this space. + * + * FLUSH_DELAYED_REFS + * We have a block reserve for the outstanding delayed refs space, and every + * delayed ref operation holds a reservation. Running these is a quick way + * to reclaim space, but we want to hold this until the end because COW can + * churn a lot and we can avoid making some extent tree modifications if we + * are able to delay for as long as possible. + * + * 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 + * our worst case reservations will likely never come true. + * + * RUN_DELAYED_IPUTS + * If we're freeing inodes we're likely freeing checksums, file extent + * items, and extent tree items. Loads of space could be freed up by these + * operations, however they won't be usable until the transaction commits. + * + * COMMIT_TRANS + * 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 + * + * Because we hold so many reservations for metadata we will allow you to + * reserve more space than is currently free in the currently allocate + * metadata space. This only happens with metadata, data does not allow + * overcommitting. + * + * You can see the current logic for when we allow overcommit in + * btrfs_can_overcommit(), but it only applies to unallocated space. If there + * is no unallocated space to be had, all reservations are kept within the + * free space in the allocated metadata chunks. + * + * Because of overcommitting, you generally want to use the + * btrfs_can_overcommit() logic for metadata allocations, as it does the right + * thing with or without extra unallocated space. + */ u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info, bool may_use_included) @@ -16,6 +165,7 @@ u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info, ASSERT(s_info); return s_info->bytes_used + s_info->bytes_reserved + s_info->bytes_pinned + s_info->bytes_readonly + + s_info->bytes_zone_unusable + (may_use_included ? s_info->bytes_may_use : 0); } @@ -28,10 +178,45 @@ 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) + list_for_each_entry(found, head, list) found->full = 0; - rcu_read_unlock(); +} + +/* + * Block groups with more than this value (percents) of unusable space will be + * scheduled for background reclaim. + */ +#define BTRFS_DEFAULT_ZONED_RECLAIM_THRESH (75) + +/* + * 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; + + ASSERT(flags & BTRFS_BLOCK_GROUP_TYPE_MASK); + + if (flags & BTRFS_BLOCK_GROUP_DATA) + return BTRFS_MAX_DATA_CHUNK_SIZE; + else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + return SZ_32M; + + /* 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); } static int create_space_info(struct btrfs_fs_info *info, u64 flags) @@ -45,13 +230,6 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags) if (!space_info) return -ENOMEM; - ret = percpu_counter_init(&space_info->total_bytes_pinned, 0, - GFP_KERNEL); - if (ret) { - kfree(space_info); - return ret; - } - for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) INIT_LIST_HEAD(&space_info->block_groups[i]); init_rwsem(&space_info->groups_sem); @@ -61,12 +239,17 @@ 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)); + + if (btrfs_is_zoned(info)) + space_info->bg_reclaim_threshold = BTRFS_DEFAULT_ZONED_RECLAIM_THRESH; ret = btrfs_sysfs_add_space_info_type(info, 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; @@ -110,29 +293,36 @@ 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; + int factor, index; - factor = btrfs_bg_type_to_factor(flags); + factor = btrfs_bg_type_to_factor(block_group->flags); - found = btrfs_find_space_info(info, flags); + found = btrfs_find_space_info(info, block_group->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->total_bytes += block_group->length; + if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags)) + found->active_total_bytes += block_group->length; + found->disk_total += block_group->length * factor; + found->bytes_used += block_group->used; + found->disk_used += block_group->used * factor; + found->bytes_readonly += block_group->bytes_super; + found->bytes_zone_unusable += block_group->zone_unusable; + if (block_group->length > 0) found->full = 0; btrfs_try_granting_tickets(info, found); spin_unlock(&found->lock); - *space_info = found; + + block_group->space_info = found; + + index = btrfs_bg_flags_to_raid_index(block_group->flags); + down_write(&found->groups_sem); + list_add_tail(&block_group->list, &found->block_groups[index]); + up_write(&found->groups_sem); } struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, @@ -143,41 +333,26 @@ 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) -{ - return (global->size << 1); -} - -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 u64 calc_available_free_space(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_info, + enum btrfs_reserve_flush_enum flush) { u64 profile; u64 avail; - u64 used; int factor; - /* Don't overcommit when in mixed mode. */ - if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) - return 0; - if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) profile = btrfs_system_alloc_profile(fs_info); else profile = btrfs_metadata_alloc_profile(fs_info); - used = btrfs_space_info_used(space_info, true); avail = atomic64_read(&fs_info->free_chunk_space); /* @@ -198,12 +373,57 @@ int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, avail >>= 3; else avail >>= 1; + return avail; +} - if (used + bytes < space_info->total_bytes + avail) +static inline u64 writable_total_bytes(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_info) +{ + /* + * On regular filesystem, all total_bytes are always writable. On zoned + * filesystem, there may be a limitation imposed by max_active_zones. + * For metadata allocation, we cannot finish an existing active block + * group to avoid a deadlock. Thus, we need to consider only the active + * groups to be writable for metadata space. + */ + if (!btrfs_is_zoned(fs_info) || (space_info->flags & BTRFS_BLOCK_GROUP_DATA)) + return space_info->total_bytes; + + return space_info->active_total_bytes; +} + +int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, + 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; + + used = btrfs_space_info_used(space_info, true); + if (btrfs_is_zoned(fs_info) && (space_info->flags & BTRFS_BLOCK_GROUP_METADATA)) + avail = 0; + else + avail = calc_available_free_space(fs_info, space_info, flush); + + if (used + bytes < writable_total_bytes(fs_info, space_info) + avail) return 1; return 0; } +static void remove_ticket(struct btrfs_space_info *space_info, + struct reserve_ticket *ticket) +{ + if (!list_empty(&ticket->list)) { + list_del_init(&ticket->list); + ASSERT(space_info->reclaim_size >= ticket->bytes); + space_info->reclaim_size -= ticket->bytes; + } +} + /* * 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. @@ -224,14 +444,14 @@ again: ticket = list_first_entry(head, struct reserve_ticket, list); - /* Check and see if our ticket can be satisified now. */ - if ((used + ticket->bytes <= space_info->total_bytes) || + /* Check and see if our ticket can be satisfied now. */ + if ((used + ticket->bytes <= writable_total_bytes(fs_info, space_info)) || btrfs_can_overcommit(fs_info, space_info, ticket->bytes, flush)) { btrfs_space_info_update_bytes_may_use(fs_info, space_info, ticket->bytes); - list_del_init(&ticket->list); + remove_ticket(space_info, ticket); ticket->bytes = 0; space_info->tickets_id++; wake_up(&ticket->wait); @@ -256,27 +476,47 @@ do { \ spin_unlock(&__rsv->lock); \ } while (0) +static const char *space_info_flag_to_str(const struct btrfs_space_info *space_info) +{ + 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(struct btrfs_fs_info *fs_info, struct btrfs_space_info *info) { + const char *flag_str = space_info_flag_to_str(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), + /* The free space could be negative in case of overcommit */ + btrfs_info(fs_info, "space_info %s has %lld free, is %sfull", + flag_str, + (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", +"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); - - 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); - + info->bytes_readonly, info->bytes_zone_unusable); } void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, @@ -288,6 +528,7 @@ void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, spin_lock(&info->lock); __btrfs_dump_space_info(fs_info, info); + dump_global_block_rsv(fs_info); spin_unlock(&info->lock); if (!dump_block_groups) @@ -298,39 +539,18 @@ again: list_for_each_entry(cache, &info->block_groups[index], list) { spin_lock(&cache->lock); btrfs_info(fs_info, - "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s", + "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu zone_unusable %s", cache->start, cache->length, cache->used, cache->pinned, - cache->reserved, cache->ro ? "[readonly]" : ""); - btrfs_dump_free_space(cache, bytes); + cache->reserved, cache->zone_unusable, + cache->ro ? "[readonly]" : ""); spin_unlock(&cache->lock); + btrfs_dump_free_space(cache, bytes); } 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); - } -} - static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, u64 to_reclaim) { @@ -349,86 +569,100 @@ static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, /* * 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_fs_info *fs_info, + struct btrfs_space_info *space_info, + u64 to_reclaim, bool wait_ordered, + bool for_preempt) { - struct btrfs_space_info *space_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: - spin_lock(&space_info->lock); - if (list_empty(&space_info->tickets) && - list_empty(&space_info->priority_tickets)) { - spin_unlock(&space_info->lock); - break; - } - spin_unlock(&space_info->lock); - loops++; if (wait_ordered && !trans) { btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); @@ -437,104 +671,28 @@ skip_async: if (time_left) break; } - delalloc_bytes = percpu_counter_sum_positive( - &fs_info->delalloc_bytes); - dio_bytes = percpu_counter_sum_positive(&fs_info->dio_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_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); + /* + * 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; - /* - * 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; + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets) && + list_empty(&space_info->priority_tickets)) { + spin_unlock(&space_info->lock); + break; + } + spin_unlock(&space_info->lock); - /* - * 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); - 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; + delalloc_bytes = percpu_counter_sum_positive( + &fs_info->delalloc_bytes); + ordered_bytes = percpu_counter_sum_positive( + &fs_info->ordered_bytes); + } } /* @@ -544,9 +702,9 @@ enospc: */ static void flush_space(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, u64 num_bytes, - int state) + enum btrfs_flush_state state, bool for_preempt) { - struct btrfs_root *root = fs_info->extent_root; + struct btrfs_root *root = fs_info->tree_root; struct btrfs_trans_handle *trans; int nr; int ret = 0; @@ -569,8 +727,11 @@ 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(fs_info, space_info, num_bytes, + state != FLUSH_DELALLOC, for_preempt); break; case FLUSH_DELAYED_REFS_NR: case FLUSH_DELAYED_REFS: @@ -588,16 +749,45 @@ static void flush_space(struct btrfs_fs_info *fs_info, break; case ALLOC_CHUNK: case ALLOC_CHUNK_FORCE: + /* + * For metadata space on zoned filesystem, reaching here means we + * don't have enough space left in active_total_bytes. Try to + * activate a block group first, because we may have inactive + * block group already allocated. + */ + ret = btrfs_zoned_activate_one_bg(fs_info, space_info, false); + if (ret < 0) + break; + else if (ret == 1) + break; + trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); break; } ret = btrfs_chunk_alloc(trans, - btrfs_metadata_alloc_profile(fs_info), + btrfs_get_alloc_profile(fs_info, space_info->flags), (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE : CHUNK_ALLOC_FORCE); btrfs_end_transaction(trans); + + /* + * For metadata space on zoned filesystem, allocating a new chunk + * is not enough. We still need to activate the block * group. + * Active the newly allocated block group by (maybe) finishing + * a block group. + */ + if (ret == 1) { + ret = btrfs_zoned_activate_one_bg(fs_info, space_info, true); + /* + * Revert to the original ret regardless we could finish + * one block group or not. + */ + if (ret >= 0) + ret = 1; + } + if (ret > 0 || ret == -ENOSPC) ret = 0; break; @@ -611,7 +801,13 @@ 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); + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + ret = btrfs_commit_transaction(trans); break; default: ret = -ENOSPC; @@ -619,7 +815,7 @@ 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; } @@ -627,57 +823,174 @@ static inline u64 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info) { - struct reserve_ticket *ticket; u64 used; - u64 expected; - u64 to_reclaim = 0; - - list_for_each_entry(ticket, &space_info->tickets, list) - to_reclaim += ticket->bytes; - list_for_each_entry(ticket, &space_info->priority_tickets, list) - to_reclaim += ticket->bytes; - 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; + u64 avail; + u64 total; + 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); 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); + /* + * We may be flushing because suddenly we have less space than we had + * before, and now we're well over-committed based on our current free + * space. If that's the case add in our overage so we make sure to put + * appropriate pressure on the flushing state machine. + */ + total = writable_total_bytes(fs_info, space_info); + if (total + avail < used) + to_reclaim += used - (total + avail); - 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(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_info) { - u64 thresh = div_factor_fine(space_info->total_bytes, 98); + u64 global_rsv_size = fs_info->global_block_rsv.reserved; + u64 ordered, delalloc; + u64 total = writable_total_bytes(fs_info, space_info); + u64 thresh; + u64 used; + + thresh = div_factor_fine(total, 90); + + lockdep_assert_held(&space_info->lock); /* 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; + + /* + * We have tickets queued, bail so we don't compete with the async + * flushers. + */ + if (space_info->reclaim_size) + 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(fs_info, space_info, + BTRFS_RESERVE_FLUSH_ALL); + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_readonly + global_rsv_size; + if (used < total) + thresh += total - 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 += fs_info->delayed_refs_rsv.reserved + + fs_info->delayed_block_rsv.reserved; + 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, + struct reserve_ticket *ticket) +{ + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + u64 min_bytes; + + 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); + if (global_rsv->reserved < min_bytes + ticket->bytes) { + spin_unlock(&global_rsv->lock); + return false; + } + global_rsv->reserved -= ticket->bytes; + remove_ticket(space_info, ticket); + ticket->bytes = 0; + wake_up(&ticket->wait); + space_info->tickets_id++; + if (global_rsv->reserved < global_rsv->size) + global_rsv->full = 0; + spin_unlock(&global_rsv->lock); + + return true; +} + /* * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets * @fs_info - fs_info for this fs @@ -698,7 +1011,9 @@ static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, { struct reserve_ticket *ticket; u64 tickets_id = space_info->tickets_id; - u64 first_ticket_bytes = 0; + const bool aborted = 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"); @@ -710,27 +1025,18 @@ static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, ticket = list_first_entry(&space_info->tickets, struct reserve_ticket, list); - /* - * 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) + if (!aborted && steal_from_global_rsv(fs_info, space_info, ticket)) return true; - if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) + if (!aborted && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) btrfs_info(fs_info, "failing ticket with %llu bytes", ticket->bytes); - list_del_init(&ticket->list); - ticket->error = -ENOSPC; + remove_ticket(space_info, ticket); + if (aborted) + ticket->error = -EIO; + else + ticket->error = -ENOSPC; wake_up(&ticket->wait); /* @@ -739,7 +1045,8 @@ static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, * here to see if we can make progress with the next ticket in * the list. */ - btrfs_try_granting_tickets(fs_info, space_info); + if (!aborted) + btrfs_try_granting_tickets(fs_info, space_info); } return (tickets_id != space_info->tickets_id); } @@ -754,7 +1061,7 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) struct btrfs_fs_info *fs_info; struct btrfs_space_info *space_info; u64 to_reclaim; - int flush_state; + enum btrfs_flush_state flush_state; int commit_cycles = 0; u64 last_tickets_id; @@ -773,7 +1080,7 @@ 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(fs_info, space_info, to_reclaim, flush_state, false); spin_lock(&space_info->lock); if (list_empty(&space_info->tickets)) { space_info->flush = 0; @@ -792,6 +1099,14 @@ 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 @@ -821,9 +1136,229 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) } while (flush_state <= COMMIT_TRANS); } -void btrfs_init_async_reclaim_work(struct work_struct *work) +/* + * 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(fs_info, space_info)) { + enum btrfs_flush_state flush; + u64 delalloc_size = 0; + u64 to_reclaim, block_rsv_size; + u64 global_rsv_size = global_rsv->reserved; + + loops++; + + /* + * 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 + + delayed_block_rsv->reserved + + delayed_refs_rsv->reserved + + trans_rsv->reserved; + if (block_rsv_size < space_info->bytes_may_use) + delalloc_size = space_info->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 (space_info->bytes_pinned > + (delayed_block_rsv->reserved + + delayed_refs_rsv->reserved)) { + to_reclaim = space_info->bytes_pinned; + flush = COMMIT_TRANS; + } else if (delayed_block_rsv->reserved > + delayed_refs_rsv->reserved) { + to_reclaim = delayed_block_rsv->reserved; + flush = FLUSH_DELAYED_ITEMS_NR; + } else { + to_reclaim = delayed_refs_rsv->reserved; + flush = FLUSH_DELAYED_REFS_NR; + } + + spin_unlock(&space_info->lock); + + /* + * 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(fs_info, 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 re-usable, 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 + * + * 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, + ALLOC_CHUNK_FORCE, +}; + +static void btrfs_async_reclaim_data_space(struct work_struct *work) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + u64 last_tickets_id; + enum btrfs_flush_state flush_state = 0; + + fs_info = container_of(work, struct btrfs_fs_info, async_data_reclaim_work); + space_info = fs_info->data_sinfo; + + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = 0; + spin_unlock(&space_info->lock); + return; + } + last_tickets_id = space_info->tickets_id; + spin_unlock(&space_info->lock); + + while (!space_info->full) { + flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false); + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = 0; + spin_unlock(&space_info->lock); + return; + } + + /* Something happened, fail everything and bail. */ + if (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(fs_info, space_info, U64_MAX, + data_flush_states[flush_state], false); + spin_lock(&space_info->lock); + if (list_empty(&space_info->tickets)) { + space_info->flush = 0; + 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(fs_info, space_info)) + flush_state = 0; + else + space_info->flush = 0; + } else { + flush_state = 0; + } + + /* Something happened, fail everything and bail. */ + if (BTRFS_FS_ERROR(fs_info)) + goto aborted_fs; + + } + spin_unlock(&space_info->lock); + } + return; + +aborted_fs: + maybe_fail_all_tickets(fs_info, space_info); + space_info->flush = 0; + spin_unlock(&space_info->lock); +} + +void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info) { - INIT_WORK(work, btrfs_async_reclaim_metadata_space); + 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[] = { @@ -839,6 +1374,7 @@ static const enum btrfs_flush_state evict_flush_states[] = { FLUSH_DELAYED_REFS, FLUSH_DELALLOC, FLUSH_DELALLOC_WAIT, + FLUSH_DELALLOC_FULL, ALLOC_CHUNK, COMMIT_TRANS, }; @@ -850,27 +1386,74 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, int states_nr) { 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) { + /* + * 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 (ticket->bytes == 0) { spin_unlock(&space_info->lock); return; } - spin_unlock(&space_info->lock); - flush_state = 0; - do { - flush_space(fs_info, space_info, to_reclaim, states[flush_state]); + while (flush_state < states_nr) { + spin_unlock(&space_info->lock); + flush_space(fs_info, space_info, to_reclaim, states[flush_state], + false); flush_state++; spin_lock(&space_info->lock); if (ticket->bytes == 0) { spin_unlock(&space_info->lock); return; } + } + + /* Attempt to steal from the global rsv if we can. */ + if (!steal_from_global_rsv(fs_info, space_info, ticket)) { + ticket->error = -ENOSPC; + remove_ticket(space_info, ticket); + } + + /* + * 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(fs_info, space_info); + spin_unlock(&space_info->lock); +} + +static void priority_reclaim_data_space(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_info, + struct reserve_ticket *ticket) +{ + spin_lock(&space_info->lock); + + /* We could have been granted before we got here. */ + if (ticket->bytes == 0) { spin_unlock(&space_info->lock); - } while (flush_state < states_nr); + return; + } + + while (!space_info->full) { + spin_unlock(&space_info->lock); + flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false); + spin_lock(&space_info->lock); + if (ticket->bytes == 0) { + spin_unlock(&space_info->lock); + return; + } + } + + ticket->error = -ENOSPC; + remove_ticket(space_info, ticket); + btrfs_try_granting_tickets(fs_info, space_info); + spin_unlock(&space_info->lock); } static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, @@ -893,7 +1476,7 @@ 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). */ - list_del_init(&ticket->list); + remove_ticket(space_info, ticket); ticket->error = -EINTR; break; } @@ -908,11 +1491,14 @@ static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, } /** - * 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 + * + * @fs_info: the filesystem + * @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. @@ -920,12 +1506,15 @@ static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, 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); break; case BTRFS_RESERVE_FLUSH_LIMIT: @@ -938,24 +1527,15 @@ static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, evict_flush_states, ARRAY_SIZE(evict_flush_states)); break; + case BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE: + priority_reclaim_data_space(fs_info, space_info, ticket); + break; default: ASSERT(0); break; } - spin_lock(&space_info->lock); ret = ticket->error; - if (ticket->bytes || ticket->error) { - /* - * Need to delete here for priority tickets. For regular tickets - * either the async reclaim job deletes the ticket from the list - * or we delete it ourselves at wait_reserve_ticket(). - */ - list_del_init(&ticket->list); - 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, @@ -964,15 +1544,52 @@ static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, * space wasn't reserved at all). */ ASSERT(!(ticket->bytes == 0 && ticket->error)); + trace_btrfs_reserve_ticket(fs_info, space_info->flags, orig_bytes, + start_ns, flush, ticket->error); return ret; } +/* + * This returns true if this flush state will go through the ordinary flushing + * code. + */ +static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush) +{ + return (flush == BTRFS_RESERVE_FLUSH_ALL) || + (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL); +} + +static inline void maybe_clamp_preempt(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_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); +} + /** - * 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 + * Try to reserve bytes from the block_rsv's space + * + * @fs_info: the filesystem + * @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 @@ -981,12 +1598,13 @@ static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, * 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_fs_info *fs_info, + struct btrfs_space_info *space_info, u64 orig_bytes, + enum btrfs_reserve_flush_enum flush) { + struct work_struct *async_work; struct reserve_ticket ticket; + u64 start_ns = 0; u64 used; int ret = 0; bool pending_tickets; @@ -994,18 +1612,32 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, ASSERT(orig_bytes); ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL); + 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); - pending_tickets = !list_empty(&space_info->tickets) || - !list_empty(&space_info->priority_tickets); + + /* + * We don't want NO_FLUSH allocations to jump everybody, they can + * generally handle ENOSPC in a different way, so treat them the same as + * normal flushers when it comes to skipping pending tickets. + */ + if (is_normal_flushing(flush) || (flush == BTRFS_RESERVE_NO_FLUSH)) + pending_tickets = !list_empty(&space_info->tickets) || + !list_empty(&space_info->priority_tickets); + else + pending_tickets = !list_empty(&space_info->priority_tickets); /* * Carry on if we have enough space (short-circuit) OR call * can_overcommit() to ensure we can overcommit to continue. */ if (!pending_tickets && - ((used + orig_bytes <= space_info->total_bytes) || + ((used + orig_bytes <= writable_total_bytes(fs_info, space_info)) || btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) { btrfs_space_info_update_bytes_may_use(fs_info, space_info, orig_bytes); @@ -1022,51 +1654,67 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { ticket.bytes = orig_bytes; ticket.error = 0; + space_info->reclaim_size += ticket.bytes; init_waitqueue_head(&ticket.wait); - if (flush == BTRFS_RESERVE_FLUSH_ALL) { + 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_DATA) { list_add_tail(&ticket.list, &space_info->tickets); if (!space_info->flush) { + /* + * 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(fs_info, space_info); + space_info->flush = 1; 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_unbound_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(fs_info, 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); + &fs_info->preempt_reclaim_work); } } spin_unlock(&space_info->lock); if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) return ret; - return handle_reserve_ticket(fs_info, space_info, &ticket, flush); + return handle_reserve_ticket(fs_info, 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 + * Trye to reserve metadata bytes from the block_rsv's space + * + * @fs_info: the filesystem + * @block_rsv: block_rsv 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 @@ -1075,23 +1723,14 @@ 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, +int btrfs_reserve_metadata_bytes(struct btrfs_fs_info *fs_info, struct btrfs_block_rsv *block_rsv, 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(fs_info, block_rsv->space_info, orig_bytes, flush); if (ret == -ENOSPC) { trace_btrfs_space_reservation(fs_info, "space_info:enospc", block_rsv->space_info->flags, @@ -1103,3 +1742,48 @@ int btrfs_reserve_metadata_bytes(struct btrfs_root *root, } return ret; } + +/** + * Try to reserve data bytes for an allocation + * + * @fs_info: the filesystem + * @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_fs_info *fs_info, u64 bytes, + enum btrfs_reserve_flush_enum flush) +{ + struct btrfs_space_info *data_sinfo = fs_info->data_sinfo; + int ret; + + ASSERT(flush == BTRFS_RESERVE_FLUSH_DATA || + flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE || + flush == BTRFS_RESERVE_NO_FLUSH); + ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_DATA); + + ret = __reserve_bytes(fs_info, data_sinfo, bytes, flush); + if (ret == -ENOSPC) { + trace_btrfs_space_reservation(fs_info, "space_info:enospc", + data_sinfo->flags, bytes, 1); + if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) + btrfs_dump_space_info(fs_info, data_sinfo, bytes, 0); + } + 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(fs_info, space_info); + spin_unlock(&space_info->lock); + } + dump_global_block_rsv(fs_info); +} |