diff options
Diffstat (limited to 'fs/bcachefs/alloc_foreground.c')
| -rw-r--r-- | fs/bcachefs/alloc_foreground.c | 1045 |
1 files changed, 1045 insertions, 0 deletions
diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c new file mode 100644 index 000000000000..e64f8449462f --- /dev/null +++ b/fs/bcachefs/alloc_foreground.c @@ -0,0 +1,1045 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Primary bucket allocation code + * + * Copyright 2012 Google, Inc. + * + * Allocation in bcache is done in terms of buckets: + * + * Each bucket has associated an 8 bit gen; this gen corresponds to the gen in + * btree pointers - they must match for the pointer to be considered valid. + * + * Thus (assuming a bucket has no dirty data or metadata in it) we can reuse a + * bucket simply by incrementing its gen. + * + * The gens (along with the priorities; it's really the gens are important but + * the code is named as if it's the priorities) are written in an arbitrary list + * of buckets on disk, with a pointer to them in the journal header. + * + * When we invalidate a bucket, we have to write its new gen to disk and wait + * for that write to complete before we use it - otherwise after a crash we + * could have pointers that appeared to be good but pointed to data that had + * been overwritten. + * + * Since the gens and priorities are all stored contiguously on disk, we can + * batch this up: We fill up the free_inc list with freshly invalidated buckets, + * call prio_write(), and when prio_write() finishes we pull buckets off the + * free_inc list and optionally discard them. + * + * free_inc isn't the only freelist - if it was, we'd often have to sleep while + * priorities and gens were being written before we could allocate. c->free is a + * smaller freelist, and buckets on that list are always ready to be used. + * + * If we've got discards enabled, that happens when a bucket moves from the + * free_inc list to the free list. + * + * It's important to ensure that gens don't wrap around - with respect to + * either the oldest gen in the btree or the gen on disk. This is quite + * difficult to do in practice, but we explicitly guard against it anyways - if + * a bucket is in danger of wrapping around we simply skip invalidating it that + * time around, and we garbage collect or rewrite the priorities sooner than we + * would have otherwise. + * + * bch2_bucket_alloc() allocates a single bucket from a specific device. + * + * bch2_bucket_alloc_set() allocates one or more buckets from different devices + * in a given filesystem. + * + * invalidate_buckets() drives all the processes described above. It's called + * from bch2_bucket_alloc() and a few other places that need to make sure free + * buckets are ready. + * + * invalidate_buckets_(lru|fifo)() find buckets that are available to be + * invalidated, and then invalidate them and stick them on the free_inc list - + * in either lru or fifo order. + */ + +#include "bcachefs.h" +#include "alloc_background.h" +#include "alloc_foreground.h" +#include "btree_gc.h" +#include "buckets.h" +#include "clock.h" +#include "debug.h" +#include "disk_groups.h" +#include "ec.h" +#include "io.h" + +#include <linux/math64.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <trace/events/bcachefs.h> + +enum bucket_alloc_ret { + ALLOC_SUCCESS, + OPEN_BUCKETS_EMPTY, + FREELIST_EMPTY, /* Allocator thread not keeping up */ +}; + +/* + * Open buckets represent a bucket that's currently being allocated from. They + * serve two purposes: + * + * - They track buckets that have been partially allocated, allowing for + * sub-bucket sized allocations - they're used by the sector allocator below + * + * - They provide a reference to the buckets they own that mark and sweep GC + * can find, until the new allocation has a pointer to it inserted into the + * btree + * + * When allocating some space with the sector allocator, the allocation comes + * with a reference to an open bucket - the caller is required to put that + * reference _after_ doing the index update that makes its allocation reachable. + */ + +void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob) +{ + struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev); + + if (ob->ec) { + bch2_ec_bucket_written(c, ob); + return; + } + + percpu_down_read(&c->mark_lock); + spin_lock(&ob->lock); + + bch2_mark_alloc_bucket(c, ca, PTR_BUCKET_NR(ca, &ob->ptr), + false, gc_pos_alloc(c, ob), 0); + ob->valid = false; + ob->type = 0; + + spin_unlock(&ob->lock); + percpu_up_read(&c->mark_lock); + + spin_lock(&c->freelist_lock); + ob->freelist = c->open_buckets_freelist; + c->open_buckets_freelist = ob - c->open_buckets; + c->open_buckets_nr_free++; + spin_unlock(&c->freelist_lock); + + closure_wake_up(&c->open_buckets_wait); +} + +void bch2_open_bucket_write_error(struct bch_fs *c, + struct open_buckets *obs, + unsigned dev) +{ + struct open_bucket *ob; + unsigned i; + + open_bucket_for_each(c, obs, ob, i) + if (ob->ptr.dev == dev && + ob->ec) + bch2_ec_bucket_cancel(c, ob); +} + +static struct open_bucket *bch2_open_bucket_alloc(struct bch_fs *c) +{ + struct open_bucket *ob; + + BUG_ON(!c->open_buckets_freelist || !c->open_buckets_nr_free); + + ob = c->open_buckets + c->open_buckets_freelist; + c->open_buckets_freelist = ob->freelist; + atomic_set(&ob->pin, 1); + ob->type = 0; + + c->open_buckets_nr_free--; + return ob; +} + +static void open_bucket_free_unused(struct bch_fs *c, + struct open_bucket *ob, + bool may_realloc) +{ + struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev); + + BUG_ON(ca->open_buckets_partial_nr >= + ARRAY_SIZE(ca->open_buckets_partial)); + + if (ca->open_buckets_partial_nr < + ARRAY_SIZE(ca->open_buckets_partial) && + may_realloc) { + spin_lock(&c->freelist_lock); + ob->on_partial_list = true; + ca->open_buckets_partial[ca->open_buckets_partial_nr++] = + ob - c->open_buckets; + spin_unlock(&c->freelist_lock); + + closure_wake_up(&c->open_buckets_wait); + closure_wake_up(&c->freelist_wait); + } else { + bch2_open_bucket_put(c, ob); + } +} + +static void verify_not_stale(struct bch_fs *c, const struct open_buckets *obs) +{ +#ifdef CONFIG_BCACHEFS_DEBUG + struct open_bucket *ob; + unsigned i; + + open_bucket_for_each(c, obs, ob, i) { + struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev); + + BUG_ON(ptr_stale(ca, &ob->ptr)); + } +#endif +} + +/* _only_ for allocating the journal on a new device: */ +long bch2_bucket_alloc_new_fs(struct bch_dev *ca) +{ + struct bucket_array *buckets; + ssize_t b; + + rcu_read_lock(); + buckets = bucket_array(ca); + + for (b = ca->mi.first_bucket; b < ca->mi.nbuckets; b++) + if (is_available_bucket(buckets->b[b].mark)) + goto success; + b = -1; +success: + rcu_read_unlock(); + return b; +} + +static inline unsigned open_buckets_reserved(enum alloc_reserve reserve) +{ + switch (reserve) { + case RESERVE_ALLOC: + return 0; + case RESERVE_BTREE: + return BTREE_NODE_OPEN_BUCKET_RESERVE; + default: + return BTREE_NODE_OPEN_BUCKET_RESERVE * 2; + } +} + +/** + * bch_bucket_alloc - allocate a single bucket from a specific device + * + * Returns index of bucket on success, 0 on failure + * */ +struct open_bucket *bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca, + enum alloc_reserve reserve, + bool may_alloc_partial, + struct closure *cl) +{ + struct bucket_array *buckets; + struct open_bucket *ob; + long bucket = 0; + + spin_lock(&c->freelist_lock); + + if (may_alloc_partial && + ca->open_buckets_partial_nr) { + ob = c->open_buckets + + ca->open_buckets_partial[--ca->open_buckets_partial_nr]; + ob->on_partial_list = false; + spin_unlock(&c->freelist_lock); + return ob; + } + + if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(reserve))) { + if (cl) + closure_wait(&c->open_buckets_wait, cl); + + if (!c->blocked_allocate_open_bucket) + c->blocked_allocate_open_bucket = local_clock(); + + spin_unlock(&c->freelist_lock); + trace_open_bucket_alloc_fail(ca, reserve); + return ERR_PTR(-OPEN_BUCKETS_EMPTY); + } + + if (likely(fifo_pop(&ca->free[RESERVE_NONE], bucket))) + goto out; + + switch (reserve) { + case RESERVE_ALLOC: + if (fifo_pop(&ca->free[RESERVE_BTREE], bucket)) + goto out; + break; + case RESERVE_BTREE: + if (fifo_used(&ca->free[RESERVE_BTREE]) * 2 >= + ca->free[RESERVE_BTREE].size && + fifo_pop(&ca->free[RESERVE_BTREE], bucket)) + goto out; + break; + case RESERVE_MOVINGGC: + if (fifo_pop(&ca->free[RESERVE_MOVINGGC], bucket)) + goto out; + break; + default: + break; + } + + if (cl) + closure_wait(&c->freelist_wait, cl); + + if (!c->blocked_allocate) + c->blocked_allocate = local_clock(); + + spin_unlock(&c->freelist_lock); + + trace_bucket_alloc_fail(ca, reserve); + return ERR_PTR(-FREELIST_EMPTY); +out: + verify_not_on_freelist(c, ca, bucket); + + ob = bch2_open_bucket_alloc(c); + + spin_lock(&ob->lock); + buckets = bucket_array(ca); + + ob->valid = true; + ob->sectors_free = ca->mi.bucket_size; + ob->ptr = (struct bch_extent_ptr) { + .type = 1 << BCH_EXTENT_ENTRY_ptr, + .gen = buckets->b[bucket].mark.gen, + .offset = bucket_to_sector(ca, bucket), + .dev = ca->dev_idx, + }; + + bucket_io_clock_reset(c, ca, bucket, READ); + bucket_io_clock_reset(c, ca, bucket, WRITE); + spin_unlock(&ob->lock); + + if (c->blocked_allocate_open_bucket) { + bch2_time_stats_update( + &c->times[BCH_TIME_blocked_allocate_open_bucket], + c->blocked_allocate_open_bucket); + c->blocked_allocate_open_bucket = 0; + } + + if (c->blocked_allocate) { + bch2_time_stats_update( + &c->times[BCH_TIME_blocked_allocate], + c->blocked_allocate); + c->blocked_allocate = 0; + } + + spin_unlock(&c->freelist_lock); + + bch2_wake_allocator(ca); + + trace_bucket_alloc(ca, reserve); + return ob; +} + +static int __dev_stripe_cmp(struct dev_stripe_state *stripe, + unsigned l, unsigned r) +{ + return ((stripe->next_alloc[l] > stripe->next_alloc[r]) - + (stripe->next_alloc[l] < stripe->next_alloc[r])); +} + +#define dev_stripe_cmp(l, r) __dev_stripe_cmp(stripe, l, r) + +struct dev_alloc_list bch2_dev_alloc_list(struct bch_fs *c, + struct dev_stripe_state *stripe, + struct bch_devs_mask *devs) +{ + struct dev_alloc_list ret = { .nr = 0 }; + struct bch_dev *ca; + unsigned i; + + for_each_member_device_rcu(ca, c, i, devs) + ret.devs[ret.nr++] = i; + + bubble_sort(ret.devs, ret.nr, dev_stripe_cmp); + return ret; +} + +void bch2_dev_stripe_increment(struct bch_fs *c, struct bch_dev *ca, + struct dev_stripe_state *stripe) +{ + u64 *v = stripe->next_alloc + ca->dev_idx; + u64 free_space = dev_buckets_free(c, ca); + u64 free_space_inv = free_space + ? div64_u64(1ULL << 48, free_space) + : 1ULL << 48; + u64 scale = *v / 4; + + if (*v + free_space_inv >= *v) + *v += free_space_inv; + else + *v = U64_MAX; + + for (v = stripe->next_alloc; + v < stripe->next_alloc + ARRAY_SIZE(stripe->next_alloc); v++) + *v = *v < scale ? 0 : *v - scale; +} + +#define BUCKET_MAY_ALLOC_PARTIAL (1 << 0) +#define BUCKET_ALLOC_USE_DURABILITY (1 << 1) + +static void add_new_bucket(struct bch_fs *c, + struct open_buckets *ptrs, + struct bch_devs_mask *devs_may_alloc, + unsigned *nr_effective, + bool *have_cache, + unsigned flags, + struct open_bucket *ob) +{ + unsigned durability = + bch_dev_bkey_exists(c, ob->ptr.dev)->mi.durability; + + __clear_bit(ob->ptr.dev, devs_may_alloc->d); + *nr_effective += (flags & BUCKET_ALLOC_USE_DURABILITY) + ? durability : 1; + *have_cache |= !durability; + + ob_push(c, ptrs, ob); +} + +static int bch2_bucket_alloc_set(struct bch_fs *c, + struct open_buckets *ptrs, + struct dev_stripe_state *stripe, + struct bch_devs_mask *devs_may_alloc, + unsigned nr_replicas, + unsigned *nr_effective, + bool *have_cache, + enum alloc_reserve reserve, + unsigned flags, + struct closure *cl) +{ + struct dev_alloc_list devs_sorted = + bch2_dev_alloc_list(c, stripe, devs_may_alloc); + struct bch_dev *ca; + bool alloc_failure = false; + unsigned i; + + BUG_ON(*nr_effective >= nr_replicas); + + for (i = 0; i < devs_sorted.nr; i++) { + struct open_bucket *ob; + + ca = rcu_dereference(c->devs[devs_sorted.devs[i]]); + if (!ca) + continue; + + if (!ca->mi.durability && *have_cache) + continue; + + ob = bch2_bucket_alloc(c, ca, reserve, + flags & BUCKET_MAY_ALLOC_PARTIAL, cl); + if (IS_ERR(ob)) { + enum bucket_alloc_ret ret = -PTR_ERR(ob); + + WARN_ON(reserve == RESERVE_MOVINGGC && + ret != OPEN_BUCKETS_EMPTY); + + if (cl) + return -EAGAIN; + if (ret == OPEN_BUCKETS_EMPTY) + return -ENOSPC; + alloc_failure = true; + continue; + } + + add_new_bucket(c, ptrs, devs_may_alloc, + nr_effective, have_cache, flags, ob); + + bch2_dev_stripe_increment(c, ca, stripe); + + if (*nr_effective >= nr_replicas) + return 0; + } + + return alloc_failure ? -ENOSPC : -EROFS; +} + +/* Allocate from stripes: */ + +/* + * XXX: use a higher watermark for allocating open buckets here: + */ +static int ec_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h) +{ + struct bch_devs_mask devs; + struct open_bucket *ob; + unsigned i, nr_have = 0, nr_data = + min_t(unsigned, h->nr_active_devs, + EC_STRIPE_MAX) - h->redundancy; + bool have_cache = true; + int ret = 0; + + BUG_ON(h->blocks.nr > nr_data); + BUG_ON(h->parity.nr > h->redundancy); + + devs = h->devs; + + open_bucket_for_each(c, &h->parity, ob, i) + __clear_bit(ob->ptr.dev, devs.d); + open_bucket_for_each(c, &h->blocks, ob, i) + __clear_bit(ob->ptr.dev, devs.d); + + percpu_down_read(&c->mark_lock); + rcu_read_lock(); + + if (h->parity.nr < h->redundancy) { + nr_have = h->parity.nr; + + ret = bch2_bucket_alloc_set(c, &h->parity, + &h->parity_stripe, + &devs, + h->redundancy, + &nr_have, + &have_cache, + RESERVE_NONE, + 0, + NULL); + if (ret) + goto err; + } + + if (h->blocks.nr < nr_data) { + nr_have = h->blocks.nr; + + ret = bch2_bucket_alloc_set(c, &h->blocks, + &h->block_stripe, + &devs, + nr_data, + &nr_have, + &have_cache, + RESERVE_NONE, + 0, + NULL); + if (ret) + goto err; + } + + rcu_read_unlock(); + percpu_up_read(&c->mark_lock); + + return bch2_ec_stripe_new_alloc(c, h); +err: + rcu_read_unlock(); + percpu_up_read(&c->mark_lock); + return -1; +} + +/* + * if we can't allocate a new stripe because there are already too many + * partially filled stripes, force allocating from an existing stripe even when + * it's to a device we don't want: + */ + +static void bucket_alloc_from_stripe(struct bch_fs *c, + struct open_buckets *ptrs, + struct write_point *wp, + struct bch_devs_mask *devs_may_alloc, + u16 target, + unsigned erasure_code, + unsigned nr_replicas, + unsigned *nr_effective, + bool *have_cache, + unsigned flags) +{ + struct dev_alloc_list devs_sorted; + struct ec_stripe_head *h; + struct open_bucket *ob; + struct bch_dev *ca; + unsigned i, ec_idx; + + if (!erasure_code) + return; + + if (nr_replicas < 2) + return; + + if (ec_open_bucket(c, ptrs)) + return; + + h = bch2_ec_stripe_head_get(c, target, erasure_code, nr_replicas - 1); + if (!h) + return; + + if (!h->s && ec_stripe_alloc(c, h)) + goto out_put_head; + + rcu_read_lock(); + devs_sorted = bch2_dev_alloc_list(c, &wp->stripe, devs_may_alloc); + rcu_read_unlock(); + + for (i = 0; i < devs_sorted.nr; i++) + open_bucket_for_each(c, &h->s->blocks, ob, ec_idx) + if (ob->ptr.dev == devs_sorted.devs[i] && + !test_and_set_bit(ec_idx, h->s->blocks_allocated)) + goto got_bucket; + goto out_put_head; +got_bucket: + ca = bch_dev_bkey_exists(c, ob->ptr.dev); + + ob->ec_idx = ec_idx; + ob->ec = h->s; + + add_new_bucket(c, ptrs, devs_may_alloc, + nr_effective, have_cache, flags, ob); + atomic_inc(&h->s->pin); +out_put_head: + bch2_ec_stripe_head_put(h); +} + +/* Sector allocator */ + +static void get_buckets_from_writepoint(struct bch_fs *c, + struct open_buckets *ptrs, + struct write_point *wp, + struct bch_devs_mask *devs_may_alloc, + unsigned nr_replicas, + unsigned *nr_effective, + bool *have_cache, + unsigned flags, + bool need_ec) +{ + struct open_buckets ptrs_skip = { .nr = 0 }; + struct open_bucket *ob; + unsigned i; + + open_bucket_for_each(c, &wp->ptrs, ob, i) { + struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev); + + if (*nr_effective < nr_replicas && + test_bit(ob->ptr.dev, devs_may_alloc->d) && + (ca->mi.durability || + (wp->type == BCH_DATA_USER && !*have_cache)) && + (ob->ec || !need_ec)) { + add_new_bucket(c, ptrs, devs_may_alloc, + nr_effective, have_cache, + flags, ob); + } else { + ob_push(c, &ptrs_skip, ob); + } + } + wp->ptrs = ptrs_skip; +} + +static int open_bucket_add_buckets(struct bch_fs *c, + struct open_buckets *ptrs, + struct write_point *wp, + struct bch_devs_list *devs_have, + u16 target, + unsigned erasure_code, + unsigned nr_replicas, + unsigned *nr_effective, + bool *have_cache, + enum alloc_reserve reserve, + unsigned flags, + struct closure *_cl) +{ + struct bch_devs_mask devs; + struct open_bucket *ob; + struct closure *cl = NULL; + unsigned i; + int ret; + + rcu_read_lock(); + devs = target_rw_devs(c, wp->type, target); + rcu_read_unlock(); + + /* Don't allocate from devices we already have pointers to: */ + for (i = 0; i < devs_have->nr; i++) + __clear_bit(devs_have->devs[i], devs.d); + + open_bucket_for_each(c, ptrs, ob, i) + __clear_bit(ob->ptr.dev, devs.d); + + if (erasure_code) { + get_buckets_from_writepoint(c, ptrs, wp, &devs, + nr_replicas, nr_effective, + have_cache, flags, true); + if (*nr_effective >= nr_replicas) + return 0; + + bucket_alloc_from_stripe(c, ptrs, wp, &devs, + target, erasure_code, + nr_replicas, nr_effective, + have_cache, flags); + if (*nr_effective >= nr_replicas) + return 0; + } + + get_buckets_from_writepoint(c, ptrs, wp, &devs, + nr_replicas, nr_effective, + have_cache, flags, false); + if (*nr_effective >= nr_replicas) + return 0; + + percpu_down_read(&c->mark_lock); + rcu_read_lock(); + +retry_blocking: + /* + * Try nonblocking first, so that if one device is full we'll try from + * other devices: + */ + ret = bch2_bucket_alloc_set(c, ptrs, &wp->stripe, &devs, + nr_replicas, nr_effective, have_cache, + reserve, flags, cl); + if (ret && ret != -EROFS && !cl && _cl) { + cl = _cl; + goto retry_blocking; + } + + rcu_read_unlock(); + percpu_up_read(&c->mark_lock); + + return ret; +} + +void bch2_open_buckets_stop_dev(struct bch_fs *c, struct bch_dev *ca, + struct open_buckets *obs, + enum bch_data_type data_type) +{ + struct open_buckets ptrs = { .nr = 0 }; + struct open_bucket *ob, *ob2; + unsigned i, j; + + open_bucket_for_each(c, obs, ob, i) { + bool drop = !ca || ob->ptr.dev == ca->dev_idx; + + if (!drop && ob->ec) { + mutex_lock(&ob->ec->lock); + open_bucket_for_each(c, &ob->ec->blocks, ob2, j) + drop |= ob2->ptr.dev == ca->dev_idx; + open_bucket_for_each(c, &ob->ec->parity, ob2, j) + drop |= ob2->ptr.dev == ca->dev_idx; + mutex_unlock(&ob->ec->lock); + } + + if (drop) + bch2_open_bucket_put(c, ob); + else + ob_push(c, &ptrs, ob); + } + + *obs = ptrs; +} + +void bch2_writepoint_stop(struct bch_fs *c, struct bch_dev *ca, + struct write_point *wp) +{ + mutex_lock(&wp->lock); + bch2_open_buckets_stop_dev(c, ca, &wp->ptrs, wp->type); + mutex_unlock(&wp->lock); +} + +static inline struct hlist_head *writepoint_hash(struct bch_fs *c, + unsigned long write_point) +{ + unsigned hash = + hash_long(write_point, ilog2(ARRAY_SIZE(c->write_points_hash))); + + return &c->write_points_hash[hash]; +} + +static struct write_point *__writepoint_find(struct hlist_head *head, + unsigned long write_point) +{ + struct write_point *wp; + + hlist_for_each_entry_rcu(wp, head, node) + if (wp->write_point == write_point) + return wp; + + return NULL; +} + +static inline bool too_many_writepoints(struct bch_fs *c, unsigned factor) +{ + u64 stranded = c->write_points_nr * c->bucket_size_max; + u64 free = bch2_fs_usage_read_short(c).free; + + return stranded * factor > free; +} + +static bool try_increase_writepoints(struct bch_fs *c) +{ + struct write_point *wp; + + if (c->write_points_nr == ARRAY_SIZE(c->write_points) || + too_many_writepoints(c, 32)) + return false; + + wp = c->write_points + c->write_points_nr++; + hlist_add_head_rcu(&wp->node, writepoint_hash(c, wp->write_point)); + return true; +} + +static bool try_decrease_writepoints(struct bch_fs *c, + unsigned old_nr) +{ + struct write_point *wp; + + mutex_lock(&c->write_points_hash_lock); + if (c->write_points_nr < old_nr) { + mutex_unlock(&c->write_points_hash_lock); + return true; + } + + if (c->write_points_nr == 1 || + !too_many_writepoints(c, 8)) { + mutex_unlock(&c->write_points_hash_lock); + return false; + } + + wp = c->write_points + --c->write_points_nr; + + hlist_del_rcu(&wp->node); + mutex_unlock(&c->write_points_hash_lock); + + bch2_writepoint_stop(c, NULL, wp); + return true; +} + +static struct write_point *writepoint_find(struct bch_fs *c, + unsigned long write_point) +{ + struct write_point *wp, *oldest; + struct hlist_head *head; + + if (!(write_point & 1UL)) { + wp = (struct write_point *) write_point; + mutex_lock(&wp->lock); + return wp; + } + + head = writepoint_hash(c, write_point); +restart_find: + wp = __writepoint_find(head, write_point); + if (wp) { +lock_wp: + mutex_lock(&wp->lock); + if (wp->write_point == write_point) + goto out; + mutex_unlock(&wp->lock); + goto restart_find; + } +restart_find_oldest: + oldest = NULL; + for (wp = c->write_points; + wp < c->write_points + c->write_points_nr; wp++) + if (!oldest || time_before64(wp->last_used, oldest->last_used)) + oldest = wp; + + mutex_lock(&oldest->lock); + mutex_lock(&c->write_points_hash_lock); + if (oldest >= c->write_points + c->write_points_nr || + try_increase_writepoints(c)) { + mutex_unlock(&c->write_points_hash_lock); + mutex_unlock(&oldest->lock); + goto restart_find_oldest; + } + + wp = __writepoint_find(head, write_point); + if (wp && wp != oldest) { + mutex_unlock(&c->write_points_hash_lock); + mutex_unlock(&oldest->lock); + goto lock_wp; + } + + wp = oldest; + hlist_del_rcu(&wp->node); + wp->write_point = write_point; + hlist_add_head_rcu(&wp->node, head); + mutex_unlock(&c->write_points_hash_lock); +out: + wp->last_used = sched_clock(); + return wp; +} + +/* + * Get us an open_bucket we can allocate from, return with it locked: + */ +struct write_point *bch2_alloc_sectors_start(struct bch_fs *c, + unsigned target, + unsigned erasure_code, + struct write_point_specifier write_point, + struct bch_devs_list *devs_have, + unsigned nr_replicas, + unsigned nr_replicas_required, + enum alloc_reserve reserve, + unsigned flags, + struct closure *cl) +{ + struct write_point *wp; + struct open_bucket *ob; + struct open_buckets ptrs; + unsigned nr_effective, write_points_nr; + unsigned ob_flags = 0; + bool have_cache; + int ret, i; + + if (!(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)) + ob_flags |= BUCKET_ALLOC_USE_DURABILITY; + + BUG_ON(!nr_replicas || !nr_replicas_required); +retry: + ptrs.nr = 0; + nr_effective = 0; + write_points_nr = c->write_points_nr; + have_cache = false; + + wp = writepoint_find(c, write_point.v); + + if (wp->type == BCH_DATA_USER) + ob_flags |= BUCKET_MAY_ALLOC_PARTIAL; + + /* metadata may not allocate on cache devices: */ + if (wp->type != BCH_DATA_USER) + have_cache = true; + + if (!target || (flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)) { + ret = open_bucket_add_buckets(c, &ptrs, wp, devs_have, + target, erasure_code, + nr_replicas, &nr_effective, + &have_cache, reserve, + ob_flags, cl); + } else { + ret = open_bucket_add_buckets(c, &ptrs, wp, devs_have, + target, erasure_code, + nr_replicas, &nr_effective, + &have_cache, reserve, + ob_flags, NULL); + if (!ret) + goto alloc_done; + + ret = open_bucket_add_buckets(c, &ptrs, wp, devs_have, + 0, erasure_code, + nr_replicas, &nr_effective, + &have_cache, reserve, + ob_flags, cl); + } +alloc_done: + BUG_ON(!ret && nr_effective < nr_replicas); + + if (erasure_code && !ec_open_bucket(c, &ptrs)) + pr_debug("failed to get ec bucket: ret %u", ret); + + if (ret == -EROFS && + nr_effective >= nr_replicas_required) + ret = 0; + + if (ret) + goto err; + + /* Free buckets we didn't use: */ + open_bucket_for_each(c, &wp->ptrs, ob, i) + open_bucket_free_unused(c, ob, wp->type == BCH_DATA_USER); + + wp->ptrs = ptrs; + + wp->sectors_free = UINT_MAX; + + open_bucket_for_each(c, &wp->ptrs, ob, i) + wp->sectors_free = min(wp->sectors_free, ob->sectors_free); + + BUG_ON(!wp->sectors_free || wp->sectors_free == UINT_MAX); + + verify_not_stale(c, &wp->ptrs); + + return wp; +err: + open_bucket_for_each(c, &wp->ptrs, ob, i) + if (ptrs.nr < ARRAY_SIZE(ptrs.v)) + ob_push(c, &ptrs, ob); + else + open_bucket_free_unused(c, ob, + wp->type == BCH_DATA_USER); + wp->ptrs = ptrs; + + mutex_unlock(&wp->lock); + + if (ret == -ENOSPC && + try_decrease_writepoints(c, write_points_nr)) + goto retry; + + return ERR_PTR(ret); +} + +/* + * Append pointers to the space we just allocated to @k, and mark @sectors space + * as allocated out of @ob + */ +void bch2_alloc_sectors_append_ptrs(struct bch_fs *c, struct write_point *wp, + struct bkey_i *k, unsigned sectors) + +{ + struct open_bucket *ob; + unsigned i; + + BUG_ON(sectors > wp->sectors_free); + wp->sectors_free -= sectors; + + open_bucket_for_each(c, &wp->ptrs, ob, i) { + struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev); + struct bch_extent_ptr tmp = ob->ptr; + + tmp.cached = !ca->mi.durability && + wp->type == BCH_DATA_USER; + + tmp.offset += ca->mi.bucket_size - ob->sectors_free; + bch2_bkey_append_ptr(k, tmp); + + BUG_ON(sectors > ob->sectors_free); + ob->sectors_free -= sectors; + } +} + +/* + * Append pointers to the space we just allocated to @k, and mark @sectors space + * as allocated out of @ob + */ +void bch2_alloc_sectors_done(struct bch_fs *c, struct write_point *wp) +{ + struct open_buckets ptrs = { .nr = 0 }, keep = { .nr = 0 }; + struct open_bucket *ob; + unsigned i; + + open_bucket_for_each(c, &wp->ptrs, ob, i) + ob_push(c, !ob->sectors_free ? &ptrs : &keep, ob); + wp->ptrs = keep; + + mutex_unlock(&wp->lock); + + bch2_open_buckets_put(c, &ptrs); +} + +void bch2_fs_allocator_foreground_init(struct bch_fs *c) +{ + struct open_bucket *ob; + struct write_point *wp; + + mutex_init(&c->write_points_hash_lock); + c->write_points_nr = ARRAY_SIZE(c->write_points); + + /* open bucket 0 is a sentinal NULL: */ + spin_lock_init(&c->open_buckets[0].lock); + + for (ob = c->open_buckets + 1; + ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) { + spin_lock_init(&ob->lock); + c->open_buckets_nr_free++; + + ob->freelist = c->open_buckets_freelist; + c->open_buckets_freelist = ob - c->open_buckets; + } + + writepoint_init(&c->btree_write_point, BCH_DATA_BTREE); + writepoint_init(&c->rebalance_write_point, BCH_DATA_USER); + + for (wp = c->write_points; + wp < c->write_points + c->write_points_nr; wp++) { + writepoint_init(wp, BCH_DATA_USER); + + wp->last_used = sched_clock(); + wp->write_point = (unsigned long) wp; + hlist_add_head_rcu(&wp->node, + writepoint_hash(c, wp->write_point)); + } +} |