Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Joe Thornber | 1260 | 54.74% | 13 | 39.39% |
Mike Snitzer | 994 | 43.18% | 9 | 27.27% |
Kent Overstreet | 12 | 0.52% | 2 | 6.06% |
Mikulas Patocka | 10 | 0.43% | 1 | 3.03% |
Christoph Hellwig | 9 | 0.39% | 2 | 6.06% |
Heinz Mauelshagen | 8 | 0.35% | 3 | 9.09% |
Kees Cook | 5 | 0.22% | 1 | 3.03% |
Alan Cox | 3 | 0.13% | 1 | 3.03% |
Geliang Tang | 1 | 0.04% | 1 | 3.03% |
Total | 2302 | 33 |
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012 Red Hat, Inc. * * This file is released under the GPL. */ #include "dm.h" #include "dm-bio-prison-v1.h" #include "dm-bio-prison-v2.h" #include <linux/spinlock.h> #include <linux/mempool.h> #include <linux/module.h> #include <linux/slab.h> /*----------------------------------------------------------------*/ #define MIN_CELLS 1024 struct prison_region { spinlock_t lock; struct rb_root cell; } ____cacheline_aligned_in_smp; struct dm_bio_prison { mempool_t cell_pool; unsigned int num_locks; struct prison_region regions[] __counted_by(num_locks); }; static struct kmem_cache *_cell_cache; /*----------------------------------------------------------------*/ /* * @nr_cells should be the number of cells you want in use _concurrently_. * Don't confuse it with the number of distinct keys. */ struct dm_bio_prison *dm_bio_prison_create(void) { int ret; unsigned int i, num_locks; struct dm_bio_prison *prison; num_locks = dm_num_hash_locks(); prison = kzalloc(struct_size(prison, regions, num_locks), GFP_KERNEL); if (!prison) return NULL; prison->num_locks = num_locks; for (i = 0; i < prison->num_locks; i++) { spin_lock_init(&prison->regions[i].lock); prison->regions[i].cell = RB_ROOT; } ret = mempool_init_slab_pool(&prison->cell_pool, MIN_CELLS, _cell_cache); if (ret) { kfree(prison); return NULL; } return prison; } EXPORT_SYMBOL_GPL(dm_bio_prison_create); void dm_bio_prison_destroy(struct dm_bio_prison *prison) { mempool_exit(&prison->cell_pool); kfree(prison); } EXPORT_SYMBOL_GPL(dm_bio_prison_destroy); struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, gfp_t gfp) { return mempool_alloc(&prison->cell_pool, gfp); } EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell); void dm_bio_prison_free_cell(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell) { mempool_free(cell, &prison->cell_pool); } EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell); static void __setup_new_cell(struct dm_cell_key *key, struct bio *holder, struct dm_bio_prison_cell *cell) { memcpy(&cell->key, key, sizeof(cell->key)); cell->holder = holder; bio_list_init(&cell->bios); } static int cmp_keys(struct dm_cell_key *lhs, struct dm_cell_key *rhs) { if (lhs->virtual < rhs->virtual) return -1; if (lhs->virtual > rhs->virtual) return 1; if (lhs->dev < rhs->dev) return -1; if (lhs->dev > rhs->dev) return 1; if (lhs->block_end <= rhs->block_begin) return -1; if (lhs->block_begin >= rhs->block_end) return 1; return 0; } static inline unsigned int lock_nr(struct dm_cell_key *key, unsigned int num_locks) { return dm_hash_locks_index((key->block_begin >> BIO_PRISON_MAX_RANGE_SHIFT), num_locks); } bool dm_cell_key_has_valid_range(struct dm_cell_key *key) { if (WARN_ON_ONCE(key->block_end - key->block_begin > BIO_PRISON_MAX_RANGE)) return false; if (WARN_ON_ONCE((key->block_begin >> BIO_PRISON_MAX_RANGE_SHIFT) != (key->block_end - 1) >> BIO_PRISON_MAX_RANGE_SHIFT)) return false; return true; } EXPORT_SYMBOL(dm_cell_key_has_valid_range); static int __bio_detain(struct rb_root *root, struct dm_cell_key *key, struct bio *inmate, struct dm_bio_prison_cell *cell_prealloc, struct dm_bio_prison_cell **cell_result) { int r; struct rb_node **new = &root->rb_node, *parent = NULL; while (*new) { struct dm_bio_prison_cell *cell = rb_entry(*new, struct dm_bio_prison_cell, node); r = cmp_keys(key, &cell->key); parent = *new; if (r < 0) new = &((*new)->rb_left); else if (r > 0) new = &((*new)->rb_right); else { if (inmate) bio_list_add(&cell->bios, inmate); *cell_result = cell; return 1; } } __setup_new_cell(key, inmate, cell_prealloc); *cell_result = cell_prealloc; rb_link_node(&cell_prealloc->node, parent, new); rb_insert_color(&cell_prealloc->node, root); return 0; } static int bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key, struct bio *inmate, struct dm_bio_prison_cell *cell_prealloc, struct dm_bio_prison_cell **cell_result) { int r; unsigned l = lock_nr(key, prison->num_locks); spin_lock_irq(&prison->regions[l].lock); r = __bio_detain(&prison->regions[l].cell, key, inmate, cell_prealloc, cell_result); spin_unlock_irq(&prison->regions[l].lock); return r; } int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key, struct bio *inmate, struct dm_bio_prison_cell *cell_prealloc, struct dm_bio_prison_cell **cell_result) { return bio_detain(prison, key, inmate, cell_prealloc, cell_result); } EXPORT_SYMBOL_GPL(dm_bio_detain); int dm_get_cell(struct dm_bio_prison *prison, struct dm_cell_key *key, struct dm_bio_prison_cell *cell_prealloc, struct dm_bio_prison_cell **cell_result) { return bio_detain(prison, key, NULL, cell_prealloc, cell_result); } EXPORT_SYMBOL_GPL(dm_get_cell); /* * @inmates must have been initialised prior to this call */ static void __cell_release(struct rb_root *root, struct dm_bio_prison_cell *cell, struct bio_list *inmates) { rb_erase(&cell->node, root); if (inmates) { if (cell->holder) bio_list_add(inmates, cell->holder); bio_list_merge(inmates, &cell->bios); } } void dm_cell_release(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell, struct bio_list *bios) { unsigned l = lock_nr(&cell->key, prison->num_locks); spin_lock_irq(&prison->regions[l].lock); __cell_release(&prison->regions[l].cell, cell, bios); spin_unlock_irq(&prison->regions[l].lock); } EXPORT_SYMBOL_GPL(dm_cell_release); /* * Sometimes we don't want the holder, just the additional bios. */ static void __cell_release_no_holder(struct rb_root *root, struct dm_bio_prison_cell *cell, struct bio_list *inmates) { rb_erase(&cell->node, root); bio_list_merge(inmates, &cell->bios); } void dm_cell_release_no_holder(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell, struct bio_list *inmates) { unsigned l = lock_nr(&cell->key, prison->num_locks); unsigned long flags; spin_lock_irqsave(&prison->regions[l].lock, flags); __cell_release_no_holder(&prison->regions[l].cell, cell, inmates); spin_unlock_irqrestore(&prison->regions[l].lock, flags); } EXPORT_SYMBOL_GPL(dm_cell_release_no_holder); void dm_cell_error(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell, blk_status_t error) { struct bio_list bios; struct bio *bio; bio_list_init(&bios); dm_cell_release(prison, cell, &bios); while ((bio = bio_list_pop(&bios))) { bio->bi_status = error; bio_endio(bio); } } EXPORT_SYMBOL_GPL(dm_cell_error); void dm_cell_visit_release(struct dm_bio_prison *prison, void (*visit_fn)(void *, struct dm_bio_prison_cell *), void *context, struct dm_bio_prison_cell *cell) { unsigned l = lock_nr(&cell->key, prison->num_locks); spin_lock_irq(&prison->regions[l].lock); visit_fn(context, cell); rb_erase(&cell->node, &prison->regions[l].cell); spin_unlock_irq(&prison->regions[l].lock); } EXPORT_SYMBOL_GPL(dm_cell_visit_release); static int __promote_or_release(struct rb_root *root, struct dm_bio_prison_cell *cell) { if (bio_list_empty(&cell->bios)) { rb_erase(&cell->node, root); return 1; } cell->holder = bio_list_pop(&cell->bios); return 0; } int dm_cell_promote_or_release(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell) { int r; unsigned l = lock_nr(&cell->key, prison->num_locks); spin_lock_irq(&prison->regions[l].lock); r = __promote_or_release(&prison->regions[l].cell, cell); spin_unlock_irq(&prison->regions[l].lock); return r; } EXPORT_SYMBOL_GPL(dm_cell_promote_or_release); /*----------------------------------------------------------------*/ #define DEFERRED_SET_SIZE 64 struct dm_deferred_entry { struct dm_deferred_set *ds; unsigned int count; struct list_head work_items; }; struct dm_deferred_set { spinlock_t lock; unsigned int current_entry; unsigned int sweeper; struct dm_deferred_entry entries[DEFERRED_SET_SIZE]; }; struct dm_deferred_set *dm_deferred_set_create(void) { int i; struct dm_deferred_set *ds; ds = kmalloc(sizeof(*ds), GFP_KERNEL); if (!ds) return NULL; spin_lock_init(&ds->lock); ds->current_entry = 0; ds->sweeper = 0; for (i = 0; i < DEFERRED_SET_SIZE; i++) { ds->entries[i].ds = ds; ds->entries[i].count = 0; INIT_LIST_HEAD(&ds->entries[i].work_items); } return ds; } EXPORT_SYMBOL_GPL(dm_deferred_set_create); void dm_deferred_set_destroy(struct dm_deferred_set *ds) { kfree(ds); } EXPORT_SYMBOL_GPL(dm_deferred_set_destroy); struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds) { unsigned long flags; struct dm_deferred_entry *entry; spin_lock_irqsave(&ds->lock, flags); entry = ds->entries + ds->current_entry; entry->count++; spin_unlock_irqrestore(&ds->lock, flags); return entry; } EXPORT_SYMBOL_GPL(dm_deferred_entry_inc); static unsigned int ds_next(unsigned int index) { return (index + 1) % DEFERRED_SET_SIZE; } static void __sweep(struct dm_deferred_set *ds, struct list_head *head) { while ((ds->sweeper != ds->current_entry) && !ds->entries[ds->sweeper].count) { list_splice_init(&ds->entries[ds->sweeper].work_items, head); ds->sweeper = ds_next(ds->sweeper); } if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count) list_splice_init(&ds->entries[ds->sweeper].work_items, head); } void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head) { unsigned long flags; spin_lock_irqsave(&entry->ds->lock, flags); BUG_ON(!entry->count); --entry->count; __sweep(entry->ds, head); spin_unlock_irqrestore(&entry->ds->lock, flags); } EXPORT_SYMBOL_GPL(dm_deferred_entry_dec); /* * Returns 1 if deferred or 0 if no pending items to delay job. */ int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work) { int r = 1; unsigned int next_entry; spin_lock_irq(&ds->lock); if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->current_entry].count) r = 0; else { list_add(work, &ds->entries[ds->current_entry].work_items); next_entry = ds_next(ds->current_entry); if (!ds->entries[next_entry].count) ds->current_entry = next_entry; } spin_unlock_irq(&ds->lock); return r; } EXPORT_SYMBOL_GPL(dm_deferred_set_add_work); /*----------------------------------------------------------------*/ static int __init dm_bio_prison_init_v1(void) { _cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0); if (!_cell_cache) return -ENOMEM; return 0; } static void dm_bio_prison_exit_v1(void) { kmem_cache_destroy(_cell_cache); _cell_cache = NULL; } static int (*_inits[])(void) __initdata = { dm_bio_prison_init_v1, dm_bio_prison_init_v2, }; static void (*_exits[])(void) = { dm_bio_prison_exit_v1, dm_bio_prison_exit_v2, }; static int __init dm_bio_prison_init(void) { const int count = ARRAY_SIZE(_inits); int r, i; for (i = 0; i < count; i++) { r = _inits[i](); if (r) goto bad; } return 0; bad: while (i--) _exits[i](); return r; } static void __exit dm_bio_prison_exit(void) { int i = ARRAY_SIZE(_exits); while (i--) _exits[i](); } /* * module hooks */ module_init(dm_bio_prison_init); module_exit(dm_bio_prison_exit); MODULE_DESCRIPTION(DM_NAME " bio prison"); MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); MODULE_LICENSE("GPL");
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