mirror of
https://github.com/schoebel/mars
synced 2024-12-17 12:14:40 +00:00
1138 lines
28 KiB
C
1138 lines
28 KiB
C
// (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG
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// Buf brick
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/* FIXME: this code has been unused for a long time, it is unlikly
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* to work at all.
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*/
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//#define BRICK_DEBUGGING
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//#define MARS_DEBUGGING
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//#define IO_DEBUGGING
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//#define STAT_DEBUGGING
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/blkdev.h>
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#include <linux/delay.h>
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#include "mars.h"
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//#define USE_VMALLOC
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//#define FAKE_IO // only for testing
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//#define FAKE_READS // only for testing
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//#define FAKE_WRITES // only for testing
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//#define OPTIMIZE_FULL_WRITES // does not work currently!
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///////////////////////// own type definitions ////////////////////////
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#include "mars_buf.h"
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#define PRE_ALLOC 8
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///////////////////////// own helper functions ////////////////////////
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static inline
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int buf_hash_fn(loff_t base_index)
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{
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// simple and stupid
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loff_t tmp;
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tmp = base_index ^ (base_index / MARS_BUF_HASH_MAX);
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//tmp ^= tmp / (MARS_BUF_HASH_MAX * MARS_BUF_HASH_MAX);
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return ((unsigned)tmp) % MARS_BUF_HASH_MAX;
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}
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static
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struct buf_head *_hash_find_insert(struct buf_brick *brick, loff_t base_index, struct buf_head *new)
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{
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int hash = buf_hash_fn(base_index);
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spinlock_t *lock = &brick->cache_anchors[hash].hash_lock;
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struct list_head *start = &brick->cache_anchors[hash].hash_anchor;
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struct list_head *tmp;
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int count = 0;
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unsigned long flags;
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traced_lock(lock, flags);
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for (tmp = start->next; tmp != start; tmp = tmp->next) {
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struct buf_head *res;
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#if 1
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if (!tmp) {
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MARS_ERR("tmp is NULL! brick = %p base_index = %lld hash = %d new = %p\n", brick, base_index, hash, new);
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//dump_stack();
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traced_unlock(lock, flags);
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return NULL;
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}
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#endif
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#if 1
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{
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static int max = 0;
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if (++count > max) {
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max = count;
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if (!(max % 10)) {
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MARS_INF("hash maxlen=%d hash=%d base_index=%llu\n", max, hash, base_index);
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}
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}
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}
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#endif
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res = container_of(tmp, struct buf_head, bf_hash_head);
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if (res->bf_base_index == base_index) { // found
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/* This must be paired with _bf_put()
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*/
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atomic_inc(&res->bf_hash_count);
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traced_unlock(lock, flags);
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return res;
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}
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}
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if (new) {
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_CHECK_ATOMIC(&new->bf_hash_count, !=, 0);
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atomic_inc(&new->bf_hash_count);
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atomic_inc(&brick->hashed_count);
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CHECK_HEAD_EMPTY(&new->bf_hash_head);
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list_add(&new->bf_hash_head, start);
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}
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traced_unlock(lock, flags);
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return NULL;
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}
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/* Try to remove bf from the hash.
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* When bf is in use, do nothing.
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*/
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static inline
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bool _remove_hash(struct buf_brick *brick, struct buf_head *bf)
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{
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int hash;
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spinlock_t *lock;
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unsigned long flags;
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bool success = false;
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hash = buf_hash_fn(bf->bf_base_index);
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lock = &brick->cache_anchors[hash].hash_lock;
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traced_lock(lock, flags);
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if (likely(!atomic_read(&bf->bf_hash_count) && !atomic_read(&bf->bf_mref_count) && !atomic_read(&bf->bf_io_count))) {
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success = true;
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if (likely(!list_empty(&bf->bf_hash_head))) {
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list_del_init(&bf->bf_hash_head);
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atomic_dec(&brick->hashed_count);
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}
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}
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traced_unlock(lock, flags);
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return success;
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}
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static inline
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void _add_bf_list(struct buf_brick *brick, struct buf_head *bf, int nr, bool at_end)
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{
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unsigned long flags;
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#if 1
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if (nr < 0 || nr >= LIST_MAX)
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MARS_FAT("bad nr %d\n", nr);
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#endif
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traced_lock(&brick->brick_lock, flags);
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atomic_inc(&brick->list_count[nr]);
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if (!list_empty(&bf->bf_list_head)) {
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atomic_dec(&brick->list_count[bf->bf_member]);
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list_del(&bf->bf_list_head);
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}
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if (at_end) {
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list_add_tail(&bf->bf_list_head, &brick->list_anchor[nr]);
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} else {
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list_add(&bf->bf_list_head, &brick->list_anchor[nr]);
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}
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bf->bf_member = nr;
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bf->bf_jiffies = jiffies;
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traced_unlock(&brick->brick_lock, flags);
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}
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static inline
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struct buf_head *_fetch_bf_list(struct buf_brick *brick, int nr, unsigned long age)
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{
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struct buf_head *bf = NULL;
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unsigned long flags;
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#if 1
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if (nr < 0 || nr >= LIST_MAX)
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MARS_FAT("bad nr %d\n", nr);
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#endif
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traced_lock(&brick->brick_lock, flags);
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if (!list_empty(&brick->list_anchor[nr])) {
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bf = container_of(brick->list_anchor[nr].prev, struct buf_head, bf_list_head);
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#if 1
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if (age != 0 && jiffies - bf->bf_jiffies < age) {
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traced_unlock(&brick->brick_lock, flags);
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return NULL;
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}
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#endif
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atomic_dec(&brick->list_count[nr]);
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list_del_init(&bf->bf_list_head);
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}
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traced_unlock(&brick->brick_lock, flags);
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return bf;
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}
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static inline
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void _remove_bf_list(struct buf_brick *brick, struct buf_head *bf)
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{
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unsigned long flags;
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#if 1
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if (bf->bf_member < 0 || bf->bf_member >= LIST_MAX)
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MARS_FAT("bad nr %d\n", bf->bf_member);
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#endif
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traced_lock(&brick->brick_lock, flags);
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if (!list_empty(&bf->bf_list_head)) {
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list_del_init(&bf->bf_list_head);
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atomic_dec(&brick->list_count[bf->bf_member]);
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}
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traced_unlock(&brick->brick_lock, flags);
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}
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static inline
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struct buf_head *_alloc_bf(struct buf_brick *brick)
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{
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struct buf_head *bf = brick_zmem_alloc(sizeof(struct buf_head));
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if (unlikely(!bf))
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goto done;
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#ifdef USE_VMALLOC
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bf->bf_data = vmalloc(brick->backing_size);
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#else
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bf->bf_data = (void*)__get_free_pages(GFP_MARS, brick->backing_order);
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#endif
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if (unlikely(!bf->bf_data)) {
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brick_mem_free(bf);
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bf = NULL;
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goto done;
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}
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atomic_inc(&brick->alloc_count);
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done:
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return bf;
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}
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static inline
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void _dealloc_bf(struct buf_brick *brick, struct buf_head *bf)
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{
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MARS_INF("really freeing bf=%p\n", bf);
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_CHECK_ATOMIC(&bf->bf_hash_count, !=, 0);
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_CHECK_ATOMIC(&bf->bf_mref_count, !=, 0);
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_CHECK_ATOMIC(&bf->bf_io_count, !=, 0);
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CHECK_HEAD_EMPTY(&bf->bf_list_head);
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CHECK_HEAD_EMPTY(&bf->bf_hash_head);
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CHECK_HEAD_EMPTY(&bf->bf_io_pending_anchor);
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CHECK_HEAD_EMPTY(&bf->bf_postpone_anchor);
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#ifdef USE_VMALLOC
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vfree(bf->bf_data);
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#else
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free_pages((unsigned long)bf->bf_data, brick->backing_order);
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#endif
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brick_mem_free(bf);
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atomic_dec(&brick->alloc_count);
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}
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static inline
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void _prune_cache(struct buf_brick *brick, int max_count)
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{
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struct buf_head *bf;
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int i;
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for (i = 0; i < LIST_MAX; i++) {
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while (atomic_read(&brick->alloc_count) > max_count) {
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bf = _fetch_bf_list(brick, i, 0);
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if (bf) {
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if (i > 0) {
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bool status;
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status = _remove_hash(brick, bf);
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if (unlikely(!status)) {
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MARS_INF("bf %p is in use\n", bf);
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continue;
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}
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}
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_dealloc_bf(brick, bf);
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}
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}
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}
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}
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static inline
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struct buf_head *_fetch_bf(struct buf_brick *brick)
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{
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struct buf_head *bf = NULL;
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while (!bf) {
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static const int ages[LIST_MAX] = {
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[LIST_FORGET] = HZ,
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};
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int i;
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for (i = 0; i < LIST_MAX; i++) {
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bf = _fetch_bf_list(brick, i, ages[i]);
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if (bf)
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goto found;
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}
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bf = _alloc_bf(brick);
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continue;
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found:
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if (i > 0) {
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bool status = _remove_hash(brick, bf);
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if (unlikely(!status)) {
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MARS_INF("bf %p is in use\n", bf);
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bf = NULL; // forget it => _bf_put() must fix it
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continue;
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}
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}
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}
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return bf;
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}
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static
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void __pre_alloc_bf(struct buf_brick *brick, int max)
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{
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while (max-- > 0) {
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struct buf_head *bf = _alloc_bf(brick);
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if (unlikely(!bf))
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break;
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INIT_LIST_HEAD(&bf->bf_list_head);
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_add_bf_list(brick, bf, LIST_FREE, true);
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}
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}
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static inline
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void _bf_put(struct buf_head *bf)
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{
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int list;
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bool at_end;
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if (!atomic_dec_and_test(&bf->bf_hash_count))
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return;
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#if 1
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MARS_DBG("ZERO_COUNT %p %d\n", bf, at_end);
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if (unlikely(!list_empty(&bf->bf_io_pending_anchor))) {
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MARS_ERR("bf_io_pending_anchor is not empty!\n");
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}
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if (unlikely(!list_empty(&bf->bf_postpone_anchor))) {
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MARS_ERR("bf_postpone_anchor is not empty!\n");
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}
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#endif
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list = LIST_LRU;
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at_end = !(bf->bf_flags & MREF_UPTODATE);
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if (bf->bf_chain_detected) {
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list = LIST_FORGET;
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at_end = false;
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}
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_add_bf_list(bf->bf_brick, bf, list, at_end);
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}
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/////////////////////////////////////////////////////////////////////////
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/* Routines for the relation bf <-> mref
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*/
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static inline
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void _mref_assign(struct buf_head *bf, struct buf_mref_aspect *mref_a)
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{
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if (mref_a->rfa_bf) {
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return;
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}
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mref_a->rfa_bf = bf;
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atomic_inc(&bf->bf_mref_count);
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}
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static inline
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bool _mref_remove(struct buf_head *bf, struct buf_mref_aspect *mref_a)
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{
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//struct mref_object *mref;
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bool status;
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if (!mref_a->rfa_bf) {
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return false;
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}
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mref_a->rfa_bf = NULL;
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CHECK_ATOMIC(&bf->bf_mref_count, 1);
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status = atomic_dec_and_test(&bf->bf_mref_count);
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return status;
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}
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/////////////////////////////////////////////////////////////7
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static inline int _get_info(struct buf_brick *brick)
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{
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struct buf_input *input = brick->inputs[0];
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int status = GENERIC_INPUT_CALL(input, mars_get_info, &brick->base_info);
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if (status >= 0)
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brick->got_info = true;
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return status;
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}
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////////////////// own brick / input / output operations //////////////////
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static int buf_get_info(struct buf_output *output, struct mars_info *info)
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{
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struct buf_input *input = output->brick->inputs[0];
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return GENERIC_INPUT_CALL(input, mars_get_info, info);
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}
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static int buf_ref_get(struct buf_output *output, struct mref_object *mref)
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{
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struct buf_brick *brick = output->brick;
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struct buf_mref_aspect *mref_a;
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struct buf_head *bf;
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struct buf_head *new = NULL;
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loff_t base_pos;
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int base_offset;
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int max_len;
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int status = -EILSEQ;
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might_sleep();
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#if 0
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if (!brick->got_info)
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_get_info(brick);
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#endif
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#ifdef PRE_ALLOC
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if (unlikely(atomic_read(&brick->alloc_count) < brick->max_count)) {
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// grab all memory in one go => avoid memory fragmentation
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__pre_alloc_bf(brick, brick->max_count + PRE_ALLOC - atomic_read(&brick->alloc_count));
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}
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#endif
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/* Grab reference.
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*/
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_CHECK_ATOMIC(&mref->ref_count, !=, 0);
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atomic_inc(&mref->ref_count);
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/* shortcut in case of unbuffered IO
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*/
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if (mref->ref_data) {
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/* Note: unbuffered IO is later indicated by rfa_bf == NULL
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*/
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return 0;
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}
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mref_a = buf_mref_get_aspect(brick, mref);
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if (unlikely(!mref_a))
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goto done;
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base_pos = mref->ref_pos & ~(loff_t)(brick->backing_size - 1);
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base_offset = (mref->ref_pos - base_pos);
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if (unlikely(base_offset < 0 || base_offset >= brick->backing_size)) {
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MARS_ERR("bad base_offset %d\n", base_offset);
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}
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max_len = brick->backing_size - base_offset;
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if (mref->ref_len > max_len)
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mref->ref_len = max_len;
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again:
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bf = _hash_find_insert(brick, base_pos >> (brick->backing_order + PAGE_SHIFT), new);
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if (bf) {
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#if 1
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loff_t end_pos = bf->bf_pos + brick->backing_size;
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if (mref->ref_pos < bf->bf_pos || mref->ref_pos >= end_pos) {
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MARS_ERR("hash corruption. %lld not in (%lld ... %lld)\n", mref->ref_pos, bf->bf_pos, end_pos);
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}
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#endif
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_remove_bf_list(brick, bf);
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atomic_inc(&brick->hit_count);
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if (unlikely(new)) {
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atomic_inc(&brick->nr_collisions);
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MARS_DBG("race detected: alias appeared in the meantime\n");
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_add_bf_list(brick, new, LIST_FREE, true);
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new = NULL;
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}
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} else if (new) {
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atomic_inc(&brick->miss_count);
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MARS_DBG("new elem added\n");
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bf = new;
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new = NULL;
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bf->bf_chain_detected = false;
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} else {
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MARS_DBG("buf_get() hash nothing found\n");
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new = _fetch_bf(brick);
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if (!new)
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goto done;
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#if 1
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// dont initialize new->bf_data
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memset(((void*)new) + sizeof(void*), 0, sizeof(struct buf_head) - sizeof(void*));
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#else
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new->bf_flags = 0;
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new->bf_error = 0;
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atomic_set(&new->bf_hash_count, 0);
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atomic_set(&new->bf_mfu_stat, 0);
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atomic_set(&new->bf_chain_len, 0);
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new->bf_chain_detected = false;
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#endif
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spin_lock_init(&new->bf_lock);
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new->bf_brick = brick;
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new->bf_pos = base_pos;
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new->bf_base_index = base_pos >> (brick->backing_order + PAGE_SHIFT);
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#ifdef OPTIMIZE_FULL_WRITES
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/* Important optimization: treat whole buffer as uptodate
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* upon full write.
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*/
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if (mref->ref_may_write != READ &&
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((!base_offset && mref->ref_len >= brick->backing_size) ||
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(mref->ref_pos >= brick->base_info.current_size && brick->base_info.current_size > 0))) {
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new->bf_flags |= MREF_UPTODATE;
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atomic_inc(&brick->opt_count);
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}
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#endif
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//INIT_LIST_HEAD(&new->bf_mref_anchor);
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INIT_LIST_HEAD(&new->bf_list_head);
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INIT_LIST_HEAD(&new->bf_hash_head);
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INIT_LIST_HEAD(&new->bf_io_pending_anchor);
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INIT_LIST_HEAD(&new->bf_postpone_anchor);
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/* Statistics for read-ahead chain detection
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*/
|
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if (brick->optimize_chains) {
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struct buf_head *prev_bf;
|
|
prev_bf = _hash_find_insert(brick, new->bf_base_index - 1, NULL);
|
|
if (prev_bf) {
|
|
int chainlen = atomic_read(&prev_bf->bf_chain_len);
|
|
atomic_set(&new->bf_chain_len, chainlen + 1);
|
|
atomic_inc(&brick->chain_count);
|
|
prev_bf->bf_chain_detected = true;
|
|
_bf_put(prev_bf);
|
|
}
|
|
}
|
|
/* Check for races against us...
|
|
*/
|
|
goto again;
|
|
}
|
|
|
|
_mref_assign(bf, mref_a);
|
|
|
|
MARS_DBG("bf=%p index = %lld flags = %d\n", bf, bf->bf_base_index, bf->bf_flags);
|
|
|
|
mref->ref_flags = bf->bf_flags;
|
|
mref->ref_data = bf->bf_data + base_offset;
|
|
|
|
CHECK_ATOMIC(&mref->ref_count, 1);
|
|
CHECK_ATOMIC(&bf->bf_hash_count, 1);
|
|
CHECK_ATOMIC(&bf->bf_mref_count, 1);
|
|
|
|
status = 0;
|
|
|
|
done:
|
|
return status;
|
|
}
|
|
|
|
static void _buf_ref_put(struct buf_output *output, struct buf_mref_aspect *mref_a)
|
|
{
|
|
struct mref_object *mref = mref_a->object;
|
|
struct buf_head *bf;
|
|
|
|
/* shortcut in case of unbuffered IO
|
|
*/
|
|
bf = mref_a->rfa_bf;
|
|
if (!bf) {
|
|
struct buf_brick *brick = output->brick;
|
|
GENERIC_INPUT_CALL(brick->inputs[0], mref_put, mref);
|
|
return;
|
|
}
|
|
|
|
CHECK_ATOMIC(&mref->ref_count, 1);
|
|
|
|
if (!atomic_dec_and_test(&mref->ref_count))
|
|
return;
|
|
|
|
MARS_DBG("buf_ref_put() mref=%p mref_a=%p bf=%p flags=%d\n", mref, mref_a, bf, bf->bf_flags);
|
|
_mref_remove(bf, mref_a);
|
|
buf_free_mref(mref);
|
|
|
|
_bf_put(bf); // paired with _hash_find_insert()
|
|
}
|
|
|
|
static void buf_ref_put(struct buf_output *output, struct mref_object *mref)
|
|
{
|
|
struct buf_mref_aspect *mref_a;
|
|
mref_a = buf_mref_get_aspect(output->brick, mref);
|
|
if (unlikely(!mref_a)) {
|
|
MARS_FAT("cannot get aspect\n");
|
|
return;
|
|
}
|
|
_buf_ref_put(output, mref_a);
|
|
}
|
|
|
|
static void _buf_endio(struct generic_callback *cb);
|
|
|
|
static int _buf_make_io(struct buf_brick *brick, struct buf_head *bf, void *start_data, loff_t start_pos, int start_len, int rw)
|
|
{
|
|
struct buf_input *input;
|
|
int status = EINVAL;
|
|
#if 1
|
|
loff_t bf_end = bf->bf_pos + brick->backing_size;
|
|
loff_t end_pos;
|
|
if (start_pos < bf->bf_pos || start_pos >= bf_end) {
|
|
MARS_ERR("bad start_pos %llu (%llu ... %llu)\n", start_pos, bf->bf_pos, bf_end);
|
|
goto done;
|
|
}
|
|
end_pos = start_pos + start_len;
|
|
if (end_pos <= bf->bf_pos || end_pos > bf_end) {
|
|
MARS_ERR("bad end_pos %llu (%llu ... %llu)\n", end_pos, bf->bf_pos, bf_end);
|
|
goto done;
|
|
}
|
|
if (!start_data) {
|
|
MARS_ERR("bad start_data\n");
|
|
goto done;
|
|
}
|
|
if (start_len <= 0) {
|
|
MARS_ERR("bad start_len %d\n", start_len);
|
|
goto done;
|
|
}
|
|
#endif
|
|
|
|
MARS_DBG("bf = %p rw = %d start = %lld len = %d flags = %d\n", bf, rw, start_pos, start_len, bf->bf_flags);
|
|
|
|
atomic_set(&bf->bf_io_count, 0);
|
|
status = -ENOMEM;
|
|
input = brick->inputs[0];
|
|
|
|
while (start_len > 0) {
|
|
struct mref_object *mref;
|
|
struct buf_mref_aspect *mref_a;
|
|
int len;
|
|
|
|
mref = buf_alloc_mref(brick);
|
|
if (unlikely(!mref))
|
|
break;
|
|
|
|
mref_a = buf_mref_get_aspect(brick, mref);
|
|
if (unlikely(!mref_a)) {
|
|
buf_free_mref(mref);
|
|
break;
|
|
}
|
|
|
|
mref_a->rfa_bf = bf;
|
|
SETUP_CALLBACK(mref, _buf_endio, mref_a);
|
|
|
|
mref->ref_pos = start_pos;
|
|
mref->ref_len = start_len;
|
|
mref->ref_may_write = rw;
|
|
mref->ref_rw = rw;
|
|
mref->ref_data = start_data;
|
|
|
|
status = GENERIC_INPUT_CALL(input, mref_get, mref);
|
|
if (status < 0) {
|
|
MARS_ERR("status = %d\n", status);
|
|
goto done;
|
|
}
|
|
|
|
/* Remember number of fired-off mrefs
|
|
*/
|
|
atomic_inc(&bf->bf_io_count);
|
|
|
|
len = mref->ref_len;
|
|
|
|
#ifndef FAKE_IO
|
|
GENERIC_INPUT_CALL(input, mref_io, mref);
|
|
#else
|
|
// fake IO for testing
|
|
mref_a->cb.cb_error = status;
|
|
mref_a->cb.cb_fn(&mref_a->cb);
|
|
#endif
|
|
|
|
GENERIC_INPUT_CALL(input, mref_put, mref);
|
|
|
|
start_data += len;
|
|
start_pos += len;
|
|
start_len -= len;
|
|
#if 1
|
|
if (start_len > 0)
|
|
MARS_ERR("cannot submit request in one go, rest=%d\n", start_len);
|
|
#endif
|
|
}
|
|
done:
|
|
return status;
|
|
}
|
|
|
|
static void _buf_endio(struct generic_callback *cb)
|
|
{
|
|
struct buf_mref_aspect *bf_mref_a = cb->cb_private;
|
|
struct mref_object *bf_mref;
|
|
struct buf_head *bf;
|
|
struct buf_brick *brick;
|
|
LIST_HEAD(tmp);
|
|
int old_flags;
|
|
unsigned long flags;
|
|
void *start_data = NULL;
|
|
loff_t start_pos = 0;
|
|
int start_len = 0;
|
|
int error = cb->cb_error;
|
|
#if 1
|
|
int count = 0;
|
|
#endif
|
|
|
|
CHECK_PTR(bf_mref_a, err);
|
|
bf_mref = bf_mref_a->object;
|
|
CHECK_PTR(bf_mref, err);
|
|
bf = bf_mref_a->rfa_bf;
|
|
CHECK_PTR(bf, err);
|
|
brick = bf->bf_brick;
|
|
CHECK_PTR(brick, err);
|
|
|
|
MARS_DBG("_buf_endio() bf_mref_a=%p bf_mref=%p bf=%p flags=%d\n", bf_mref_a, bf_mref, bf, bf->bf_flags);
|
|
|
|
if (error < 0)
|
|
bf->bf_error = error;
|
|
|
|
// wait until all IO on this bf is completed.
|
|
if (!atomic_dec_and_test(&bf->bf_io_count))
|
|
return;
|
|
|
|
MARS_DBG("_buf_endio() ZERO bf=%p\n", bf);
|
|
|
|
// get an extra reference, to avoid freeing bf underneath during callbacks
|
|
CHECK_ATOMIC(&bf->bf_hash_count, 1);
|
|
atomic_inc(&bf->bf_hash_count);
|
|
|
|
traced_lock(&bf->bf_lock, flags);
|
|
|
|
// update flags. this must be done before the callbacks.
|
|
old_flags = bf->bf_flags;
|
|
if (bf->bf_error >= 0 && (old_flags & MREF_READING)) {
|
|
bf->bf_flags |= MREF_UPTODATE;
|
|
}
|
|
|
|
// clear the flags, callbacks must not see them. may be re-enabled later.
|
|
bf->bf_flags &= ~(MREF_READING | MREF_WRITING);
|
|
/* Remember current version of pending list.
|
|
* This is necessary because later the callbacks might
|
|
* change it underneath.
|
|
*/
|
|
if (!list_empty(&bf->bf_io_pending_anchor)) {
|
|
struct list_head *next = bf->bf_io_pending_anchor.next;
|
|
list_del_init(&bf->bf_io_pending_anchor);
|
|
list_add_tail(&tmp, next);
|
|
}
|
|
|
|
/* Move pending jobs to work.
|
|
* This is in essence an automatic restart mechanism.
|
|
* do this before the callbacks, because they may start
|
|
* new IOs. If not done in the right order, this could violate
|
|
* IO ordering semantics.
|
|
*/
|
|
while (!list_empty(&bf->bf_postpone_anchor)) {
|
|
struct buf_mref_aspect *mref_a = container_of(bf->bf_postpone_anchor.next, struct buf_mref_aspect, rfa_pending_head);
|
|
struct mref_object *mref = mref_a->object;
|
|
|
|
if (mref_a->rfa_bf != bf) {
|
|
MARS_ERR("bad pointers %p != %p\n", mref_a->rfa_bf, bf);
|
|
}
|
|
#if 1
|
|
if (!(++count % 1000)) {
|
|
MARS_ERR("endless loop 1\n");
|
|
}
|
|
#endif
|
|
list_del_init(&mref_a->rfa_pending_head);
|
|
list_add_tail(&mref_a->rfa_pending_head, &bf->bf_io_pending_anchor);
|
|
|
|
MARS_DBG("postponed mref=%p\n", mref);
|
|
|
|
// re-enable flags
|
|
bf->bf_flags |= MREF_WRITING;
|
|
bf->bf_error = 0;
|
|
|
|
if (!start_len) {
|
|
// first time: only flush the affected area
|
|
start_data = mref->ref_data;
|
|
start_pos = mref->ref_pos;
|
|
start_len = mref->ref_len;
|
|
} else if (start_data != mref->ref_data ||
|
|
start_pos != mref->ref_pos ||
|
|
start_len != mref->ref_len) {
|
|
// another time: flush larger parts
|
|
loff_t start_diff = mref->ref_pos - start_pos;
|
|
loff_t end_diff;
|
|
if (start_diff < 0) {
|
|
start_data += start_diff;
|
|
start_pos += start_diff;
|
|
start_len -= start_diff;
|
|
}
|
|
end_diff = (mref->ref_pos + mref->ref_len) - (start_pos + start_len);
|
|
if (end_diff > 0) {
|
|
start_len += end_diff;
|
|
}
|
|
}
|
|
}
|
|
|
|
traced_unlock(&bf->bf_lock, flags);
|
|
|
|
/* Signal success by calling all callbacks.
|
|
* Thanks to the tmp list, we can do this outside the spinlock.
|
|
*/
|
|
count = 0;
|
|
while (!list_empty(&tmp)) {
|
|
struct buf_mref_aspect *mref_a = container_of(tmp.next, struct buf_mref_aspect, rfa_pending_head);
|
|
struct mref_object *mref = mref_a->object;
|
|
|
|
if (mref_a->rfa_bf != bf) {
|
|
MARS_ERR("bad pointers %p != %p\n", mref_a->rfa_bf, bf);
|
|
}
|
|
#if 1
|
|
if (!(++count % 1000)) {
|
|
MARS_ERR("endless loop 2\n");
|
|
}
|
|
#endif
|
|
CHECK_ATOMIC(&mref->ref_count, 1);
|
|
/* It should be safe to do this without locking, because
|
|
* tmp is on the stack, so there is no concurrency.
|
|
*/
|
|
list_del_init(&mref_a->rfa_pending_head);
|
|
|
|
// update infos for callbacks, they may inspect it.
|
|
mref->ref_flags = bf->bf_flags;
|
|
|
|
CHECKED_CALLBACK(mref, bf->bf_error, err);
|
|
|
|
atomic_dec(&brick->nr_io_pending);
|
|
|
|
_buf_ref_put(brick->outputs[0], mref_a);
|
|
}
|
|
|
|
if (start_len) {
|
|
MARS_DBG("ATTENTION restart %d\n", start_len);
|
|
_buf_make_io(brick, bf, start_data, start_pos, start_len, WRITE);
|
|
}
|
|
// drop the extra reference from above
|
|
_bf_put(bf);
|
|
return;
|
|
|
|
err:
|
|
MARS_FAT("giving up.\n");
|
|
}
|
|
|
|
static void buf_ref_io(struct buf_output *output, struct mref_object *mref)
|
|
{
|
|
struct buf_brick *brick = output->brick;
|
|
struct buf_mref_aspect *mref_a;
|
|
struct buf_head *bf;
|
|
void *start_data = NULL;
|
|
loff_t start_pos = 0;
|
|
int start_len = 0;
|
|
int status = -EINVAL;
|
|
bool delay = false;
|
|
unsigned long flags;
|
|
|
|
if (unlikely(!mref)) {
|
|
MARS_FAT("internal problem: forgotten to supply mref\n");
|
|
goto fatal;
|
|
}
|
|
mref_a = buf_mref_get_aspect(brick, mref);
|
|
if (unlikely(!mref_a)) {
|
|
MARS_ERR("internal problem: mref aspect does not work\n");
|
|
goto fatal;
|
|
}
|
|
/* shortcut in case of unbuffered IO
|
|
*/
|
|
bf = mref_a->rfa_bf;
|
|
if (!bf) {
|
|
GENERIC_INPUT_CALL(brick->inputs[0], mref_io, mref);
|
|
return;
|
|
}
|
|
|
|
/* Grab an extra reference.
|
|
* This will be released later in _bf_endio() after
|
|
* calling the callbacks.
|
|
*/
|
|
CHECK_ATOMIC(&mref->ref_count, 1);
|
|
atomic_inc(&mref->ref_count);
|
|
CHECK_ATOMIC(&bf->bf_hash_count, 1);
|
|
|
|
MARS_DBG("IO mref=%p rw=%d bf=%p flags=%d\n", mref, mref->ref_rw, bf, bf->bf_flags);
|
|
|
|
if (mref->ref_rw != READ) {
|
|
loff_t end;
|
|
if (unlikely(mref->ref_may_write == READ)) {
|
|
MARS_ERR("sorry, you have forgotten to set ref_may_write\n");
|
|
goto callback;
|
|
}
|
|
end = mref->ref_pos + mref->ref_len;
|
|
//FIXME: race condition :(
|
|
if (!brick->got_info)
|
|
_get_info(brick);
|
|
if (end > brick->base_info.current_size) {
|
|
brick->base_info.current_size = end;
|
|
}
|
|
}
|
|
|
|
#if 1
|
|
if (jiffies - brick->last_jiffies >= 30 * HZ) {
|
|
unsigned long hit = atomic_read(&brick->hit_count);
|
|
unsigned long miss = atomic_read(&brick->miss_count);
|
|
unsigned long perc = hit * 100 * 100 / (hit + miss);
|
|
brick->last_jiffies = jiffies;
|
|
MARS_INF("BUF %p STATISTICS: alloc=%d hashed=%d free=%d forget=%d lru=%d io_pending=%d hit=%lu (%lu.%02lu%%) miss=%lu collisions=%d opt=%d chain=%d post=%d write=%d io=%d\n", brick, atomic_read(&brick->alloc_count), atomic_read(&brick->hashed_count), atomic_read(&brick->list_count[LIST_FREE]), atomic_read(&brick->list_count[LIST_FORGET]), atomic_read(&brick->list_count[LIST_LRU]), atomic_read(&brick->nr_io_pending), hit, perc / 100, perc % 100, miss, atomic_read(&brick->nr_collisions), atomic_read(&brick->opt_count), atomic_read(&brick->chain_count), atomic_read(&brick->post_count), atomic_read(&brick->write_count), atomic_read(&brick->io_count));
|
|
}
|
|
#endif
|
|
|
|
traced_lock(&bf->bf_lock, flags);
|
|
|
|
if (!list_empty(&mref_a->rfa_pending_head)) {
|
|
MARS_ERR("trying to start IO on an already started mref\n");
|
|
goto already_done;
|
|
}
|
|
|
|
if (mref->ref_rw != 0) { // WRITE
|
|
#ifdef FAKE_WRITES
|
|
bf->bf_flags |= MREF_UPTODATE;
|
|
goto already_done;
|
|
#endif
|
|
if (bf->bf_flags & MREF_READING) {
|
|
MARS_ERR("bad bf_flags %d\n", bf->bf_flags);
|
|
}
|
|
if (!(bf->bf_flags & MREF_WRITING)) {
|
|
#if 0
|
|
// by definition, a writeout buffer is always uptodate
|
|
bf->bf_flags |= (MREF_WRITING | MREF_UPTODATE);
|
|
#else // wirklich???
|
|
bf->bf_flags |= MREF_WRITING;
|
|
#endif
|
|
bf->bf_error = 0;
|
|
#if 1
|
|
start_data = mref->ref_data;
|
|
start_pos = mref->ref_pos;
|
|
start_len = mref->ref_len;
|
|
#else // only for testing: write the full buffer
|
|
start_data = (void*)((unsigned long)mref->ref_data & ~(unsigned long)(brick->backing_size - 1));
|
|
start_pos = mref->ref_pos & ~(loff_t)(brick->backing_size - 1);
|
|
start_len = brick->backing_size;
|
|
#endif
|
|
list_add(&mref_a->rfa_pending_head, &bf->bf_io_pending_anchor);
|
|
delay = true;
|
|
} else {
|
|
list_add(&mref_a->rfa_pending_head, &bf->bf_postpone_anchor);
|
|
atomic_inc(&brick->post_count);
|
|
delay = true;
|
|
MARS_DBG("postponing %lld %d\n", mref->ref_pos, mref->ref_len);
|
|
}
|
|
} else { // READ
|
|
#ifdef FAKE_READS
|
|
bf->bf_flags |= MREF_UPTODATE;
|
|
goto already_done;
|
|
#endif
|
|
#if 0
|
|
if (bf->bf_flags & (MREF_UPTODATE | MREF_WRITING))
|
|
#else
|
|
if (bf->bf_flags & MREF_UPTODATE)
|
|
#endif
|
|
goto already_done;
|
|
if (!(bf->bf_flags & MREF_READING)) {
|
|
bf->bf_flags |= MREF_READING;
|
|
bf->bf_error = 0;
|
|
|
|
// always read the whole buffer.
|
|
start_data = (void*)((unsigned long)mref->ref_data & ~(unsigned long)(brick->backing_size - 1));
|
|
start_pos = mref->ref_pos & ~(loff_t)(brick->backing_size - 1);
|
|
start_len = brick->backing_size;
|
|
}
|
|
list_add(&mref_a->rfa_pending_head, &bf->bf_io_pending_anchor);
|
|
delay = true;
|
|
}
|
|
|
|
if (likely(delay)) {
|
|
atomic_inc(&brick->nr_io_pending);
|
|
atomic_inc(&brick->io_count);
|
|
if (mref->ref_rw != 0)
|
|
atomic_inc(&brick->write_count);
|
|
}
|
|
|
|
traced_unlock(&bf->bf_lock, flags);
|
|
|
|
if (!start_len) {
|
|
// nothing to start, IO is already started.
|
|
goto no_callback;
|
|
}
|
|
|
|
status = _buf_make_io(brick, bf, start_data, start_pos, start_len, mref->ref_rw);
|
|
if (likely(status >= 0)) {
|
|
/* No immediate callback, this time.
|
|
* Callbacks will be called later from _bf_endio().
|
|
*/
|
|
goto no_callback;
|
|
}
|
|
|
|
MARS_ERR("error %d during buf_ref_io()\n", status);
|
|
buf_ref_put(output, mref);
|
|
goto callback;
|
|
|
|
already_done:
|
|
status = bf->bf_error;
|
|
|
|
traced_unlock(&bf->bf_lock, flags);
|
|
|
|
callback:
|
|
mref->ref_flags = bf->bf_flags;
|
|
CHECKED_CALLBACK(mref, status, fatal);
|
|
|
|
no_callback:
|
|
if (!delay) {
|
|
buf_ref_put(output, mref);
|
|
} // else the ref_put() will be carried out upon IO completion.
|
|
|
|
return;
|
|
fatal: // no chance to call callback: may produce hanging tasks :(
|
|
MARS_FAT("no chance to call callback, tasks may hang.\n");
|
|
}
|
|
|
|
//////////////// object / aspect constructors / destructors ///////////////
|
|
|
|
static int buf_mref_aspect_init_fn(struct generic_aspect *_ini)
|
|
{
|
|
struct buf_mref_aspect *ini = (void*)_ini;
|
|
ini->rfa_bf = NULL;
|
|
INIT_LIST_HEAD(&ini->rfa_pending_head);
|
|
//INIT_LIST_HEAD(&ini->tmp_head);
|
|
return 0;
|
|
}
|
|
|
|
static void buf_mref_aspect_exit_fn(struct generic_aspect *_ini)
|
|
{
|
|
struct buf_mref_aspect *ini = (void*)_ini;
|
|
(void)ini;
|
|
#if 1
|
|
CHECK_HEAD_EMPTY(&ini->rfa_pending_head);
|
|
//CHECK_HEAD_EMPTY(&ini->tmp_head);
|
|
#endif
|
|
}
|
|
|
|
MARS_MAKE_STATICS(buf);
|
|
|
|
////////////////////// brick constructors / destructors ////////////////////
|
|
|
|
static int buf_brick_construct(struct buf_brick *brick)
|
|
{
|
|
int i;
|
|
brick->backing_order = 0;
|
|
brick->backing_size = PAGE_SIZE;
|
|
brick->max_count = 32;
|
|
spin_lock_init(&brick->brick_lock);
|
|
for (i = 0; i < LIST_MAX; i++) {
|
|
INIT_LIST_HEAD(&brick->list_anchor[i]);
|
|
}
|
|
for (i = 0; i < MARS_BUF_HASH_MAX; i++) {
|
|
spin_lock_init(&brick->cache_anchors[i].hash_lock);
|
|
INIT_LIST_HEAD(&brick->cache_anchors[i].hash_anchor);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int buf_output_construct(struct buf_output *output)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int buf_brick_destruct(struct buf_brick *brick)
|
|
{
|
|
int i;
|
|
|
|
brick->max_count = 0;
|
|
_prune_cache(brick, 0);
|
|
|
|
for (i = 0; i < LIST_MAX; i++) {
|
|
CHECK_HEAD_EMPTY(&brick->list_anchor[i]);
|
|
}
|
|
for (i = 0; i < MARS_BUF_HASH_MAX; i++) {
|
|
CHECK_HEAD_EMPTY(&brick->cache_anchors[i].hash_anchor);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
///////////////////////// static structs ////////////////////////
|
|
|
|
static struct buf_brick_ops buf_brick_ops = {
|
|
};
|
|
|
|
static struct buf_output_ops buf_output_ops = {
|
|
.mars_get_info = buf_get_info,
|
|
.mref_get = buf_ref_get,
|
|
.mref_put = buf_ref_put,
|
|
.mref_io = buf_ref_io,
|
|
};
|
|
|
|
const struct buf_input_type buf_input_type = {
|
|
.type_name = "buf_input",
|
|
.input_size = sizeof(struct buf_input),
|
|
};
|
|
|
|
static const struct buf_input_type *buf_input_types[] = {
|
|
&buf_input_type,
|
|
};
|
|
|
|
const struct buf_output_type buf_output_type = {
|
|
.type_name = "buf_output",
|
|
.output_size = sizeof(struct buf_output),
|
|
.master_ops = &buf_output_ops,
|
|
.output_construct = &buf_output_construct,
|
|
};
|
|
|
|
static const struct buf_output_type *buf_output_types[] = {
|
|
&buf_output_type,
|
|
};
|
|
|
|
const struct buf_brick_type buf_brick_type = {
|
|
.type_name = "buf_brick",
|
|
.brick_size = sizeof(struct buf_brick),
|
|
.max_inputs = 1,
|
|
.max_outputs = 1,
|
|
.master_ops = &buf_brick_ops,
|
|
.aspect_types = buf_aspect_types,
|
|
.default_input_types = buf_input_types,
|
|
.default_output_types = buf_output_types,
|
|
.brick_construct = &buf_brick_construct,
|
|
.brick_destruct = &buf_brick_destruct,
|
|
};
|
|
EXPORT_SYMBOL_GPL(buf_brick_type);
|
|
|
|
////////////////// module init stuff /////////////////////////
|
|
|
|
int __init init_mars_buf(void)
|
|
{
|
|
MARS_INF("init_buf()\n");
|
|
return buf_register_brick_type();
|
|
}
|
|
|
|
void __exit exit_mars_buf(void)
|
|
{
|
|
MARS_INF("exit_buf()\n");
|
|
buf_unregister_brick_type();
|
|
}
|
|
|
|
#ifndef CONFIG_MARS_HAVE_BIGMODULE
|
|
MODULE_DESCRIPTION("MARS buf brick");
|
|
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(init_mars_buf);
|
|
module_exit(exit_mars_buf);
|
|
#endif
|