--- /dev/null
+/*
+ * Copyright (C) 2012 Fusion-io All rights reserved.
+ * Copyright (C) 2012 Intel Corp. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
+#include <linux/random.h>
+#include <linux/iocontext.h>
+#include <linux/capability.h>
+#include <linux/ratelimit.h>
+#include <linux/kthread.h>
+#include <linux/raid/pq.h>
+#include <linux/hash.h>
+#include <linux/list_sort.h>
+#include <linux/raid/xor.h>
+#include <asm/div64.h>
+#include "compat.h"
+#include "ctree.h"
+#include "extent_map.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "raid56.h"
+#include "async-thread.h"
+#include "check-integrity.h"
+#include "rcu-string.h"
+
+/* set when additional merges to this rbio are not allowed */
+#define RBIO_RMW_LOCKED_BIT 1
+
+/*
+ * set when this rbio is sitting in the hash, but it is just a cache
+ * of past RMW
+ */
+#define RBIO_CACHE_BIT 2
+
+/*
+ * set when it is safe to trust the stripe_pages for caching
+ */
+#define RBIO_CACHE_READY_BIT 3
+
+
+#define RBIO_CACHE_SIZE 1024
+
+struct btrfs_raid_bio {
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_bio *bbio;
+
+ /*
+ * logical block numbers for the start of each stripe
+ * The last one or two are p/q. These are sorted,
+ * so raid_map[0] is the start of our full stripe
+ */
+ u64 *raid_map;
+
+ /* while we're doing rmw on a stripe
+ * we put it into a hash table so we can
+ * lock the stripe and merge more rbios
+ * into it.
+ */
+ struct list_head hash_list;
+
+ /*
+ * LRU list for the stripe cache
+ */
+ struct list_head stripe_cache;
+
+ /*
+ * for scheduling work in the helper threads
+ */
+ struct btrfs_work work;
+
+ /*
+ * bio list and bio_list_lock are used
+ * to add more bios into the stripe
+ * in hopes of avoiding the full rmw
+ */
+ struct bio_list bio_list;
+ spinlock_t bio_list_lock;
+
+ /* also protected by the bio_list_lock, the
+ * plug list is used by the plugging code
+ * to collect partial bios while plugged. The
+ * stripe locking code also uses it to hand off
+ * the stripe lock to the next pending IO
+ */
+ struct list_head plug_list;
+
+ /*
+ * flags that tell us if it is safe to
+ * merge with this bio
+ */
+ unsigned long flags;
+
+ /* size of each individual stripe on disk */
+ int stripe_len;
+
+ /* number of data stripes (no p/q) */
+ int nr_data;
+
+ /*
+ * set if we're doing a parity rebuild
+ * for a read from higher up, which is handled
+ * differently from a parity rebuild as part of
+ * rmw
+ */
+ int read_rebuild;
+
+ /* first bad stripe */
+ int faila;
+
+ /* second bad stripe (for raid6 use) */
+ int failb;
+
+ /*
+ * number of pages needed to represent the full
+ * stripe
+ */
+ int nr_pages;
+
+ /*
+ * size of all the bios in the bio_list. This
+ * helps us decide if the rbio maps to a full
+ * stripe or not
+ */
+ int bio_list_bytes;
+
+ atomic_t refs;
+
+ /*
+ * these are two arrays of pointers. We allocate the
+ * rbio big enough to hold them both and setup their
+ * locations when the rbio is allocated
+ */
+
+ /* pointers to pages that we allocated for
+ * reading/writing stripes directly from the disk (including P/Q)
+ */
+ struct page **stripe_pages;
+
+ /*
+ * pointers to the pages in the bio_list. Stored
+ * here for faster lookup
+ */
+ struct page **bio_pages;
+};
+
+static int __raid56_parity_recover(struct btrfs_raid_bio *rbio);
+static noinline void finish_rmw(struct btrfs_raid_bio *rbio);
+static void rmw_work(struct btrfs_work *work);
+static void read_rebuild_work(struct btrfs_work *work);
+static void async_rmw_stripe(struct btrfs_raid_bio *rbio);
+static void async_read_rebuild(struct btrfs_raid_bio *rbio);
+static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio);
+static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed);
+static void __free_raid_bio(struct btrfs_raid_bio *rbio);
+static void index_rbio_pages(struct btrfs_raid_bio *rbio);
+static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
+
+/*
+ * the stripe hash table is used for locking, and to collect
+ * bios in hopes of making a full stripe
+ */
+int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
+{
+ struct btrfs_stripe_hash_table *table;
+ struct btrfs_stripe_hash_table *x;
+ struct btrfs_stripe_hash *cur;
+ struct btrfs_stripe_hash *h;
+ int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
+ int i;
+
+ if (info->stripe_hash_table)
+ return 0;
+
+ table = kzalloc(sizeof(*table) + sizeof(*h) * num_entries, GFP_NOFS);
+ if (!table)
+ return -ENOMEM;
+
+ spin_lock_init(&table->cache_lock);
+ INIT_LIST_HEAD(&table->stripe_cache);
+
+ h = table->table;
+
+ for (i = 0; i < num_entries; i++) {
+ cur = h + i;
+ INIT_LIST_HEAD(&cur->hash_list);
+ spin_lock_init(&cur->lock);
+ init_waitqueue_head(&cur->wait);
+ }
+
+ x = cmpxchg(&info->stripe_hash_table, NULL, table);
+ if (x)
+ kfree(x);
+ return 0;
+}
+
+/*
+ * caching an rbio means to copy anything from the
+ * bio_pages array into the stripe_pages array. We
+ * use the page uptodate bit in the stripe cache array
+ * to indicate if it has valid data
+ *
+ * once the caching is done, we set the cache ready
+ * bit.
+ */
+static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
+{
+ int i;
+ char *s;
+ char *d;
+ int ret;
+
+ ret = alloc_rbio_pages(rbio);
+ if (ret)
+ return;
+
+ for (i = 0; i < rbio->nr_pages; i++) {
+ if (!rbio->bio_pages[i])
+ continue;
+
+ s = kmap(rbio->bio_pages[i]);
+ d = kmap(rbio->stripe_pages[i]);
+
+ memcpy(d, s, PAGE_CACHE_SIZE);
+
+ kunmap(rbio->bio_pages[i]);
+ kunmap(rbio->stripe_pages[i]);
+ SetPageUptodate(rbio->stripe_pages[i]);
+ }
+ set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
+}
+
+/*
+ * we hash on the first logical address of the stripe
+ */
+static int rbio_bucket(struct btrfs_raid_bio *rbio)
+{
+ u64 num = rbio->raid_map[0];
+
+ /*
+ * we shift down quite a bit. We're using byte
+ * addressing, and most of the lower bits are zeros.
+ * This tends to upset hash_64, and it consistently
+ * returns just one or two different values.
+ *
+ * shifting off the lower bits fixes things.
+ */
+ return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
+}
+
+/*
+ * stealing an rbio means taking all the uptodate pages from the stripe
+ * array in the source rbio and putting them into the destination rbio
+ */
+static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
+{
+ int i;
+ struct page *s;
+ struct page *d;
+
+ if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
+ return;
+
+ for (i = 0; i < dest->nr_pages; i++) {
+ s = src->stripe_pages[i];
+ if (!s || !PageUptodate(s)) {
+ continue;
+ }
+
+ d = dest->stripe_pages[i];
+ if (d)
+ __free_page(d);
+
+ dest->stripe_pages[i] = s;
+ src->stripe_pages[i] = NULL;
+ }
+}
+
+/*
+ * merging means we take the bio_list from the victim and
+ * splice it into the destination. The victim should
+ * be discarded afterwards.
+ *
+ * must be called with dest->rbio_list_lock held
+ */
+static void merge_rbio(struct btrfs_raid_bio *dest,
+ struct btrfs_raid_bio *victim)
+{
+ bio_list_merge(&dest->bio_list, &victim->bio_list);
+ dest->bio_list_bytes += victim->bio_list_bytes;
+ bio_list_init(&victim->bio_list);
+}
+
+/*
+ * used to prune items that are in the cache. The caller
+ * must hold the hash table lock.
+ */
+static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
+{
+ int bucket = rbio_bucket(rbio);
+ struct btrfs_stripe_hash_table *table;
+ struct btrfs_stripe_hash *h;
+ int freeit = 0;
+
+ /*
+ * check the bit again under the hash table lock.
+ */
+ if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
+ return;
+
+ table = rbio->fs_info->stripe_hash_table;
+ h = table->table + bucket;
+
+ /* hold the lock for the bucket because we may be
+ * removing it from the hash table
+ */
+ spin_lock(&h->lock);
+
+ /*
+ * hold the lock for the bio list because we need
+ * to make sure the bio list is empty
+ */
+ spin_lock(&rbio->bio_list_lock);
+
+ if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
+ list_del_init(&rbio->stripe_cache);
+ table->cache_size -= 1;
+ freeit = 1;
+
+ /* if the bio list isn't empty, this rbio is
+ * still involved in an IO. We take it out
+ * of the cache list, and drop the ref that
+ * was held for the list.
+ *
+ * If the bio_list was empty, we also remove
+ * the rbio from the hash_table, and drop
+ * the corresponding ref
+ */
+ if (bio_list_empty(&rbio->bio_list)) {
+ if (!list_empty(&rbio->hash_list)) {
+ list_del_init(&rbio->hash_list);
+ atomic_dec(&rbio->refs);
+ BUG_ON(!list_empty(&rbio->plug_list));
+ }
+ }
+ }
+
+ spin_unlock(&rbio->bio_list_lock);
+ spin_unlock(&h->lock);
+
+ if (freeit)
+ __free_raid_bio(rbio);
+}
+
+/*
+ * prune a given rbio from the cache
+ */
+static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
+{
+ struct btrfs_stripe_hash_table *table;
+ unsigned long flags;
+
+ if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
+ return;
+
+ table = rbio->fs_info->stripe_hash_table;
+
+ spin_lock_irqsave(&table->cache_lock, flags);
+ __remove_rbio_from_cache(rbio);
+ spin_unlock_irqrestore(&table->cache_lock, flags);
+}
+
+/*
+ * remove everything in the cache
+ */
+void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
+{
+ struct btrfs_stripe_hash_table *table;
+ unsigned long flags;
+ struct btrfs_raid_bio *rbio;
+
+ table = info->stripe_hash_table;
+
+ spin_lock_irqsave(&table->cache_lock, flags);
+ while (!list_empty(&table->stripe_cache)) {
+ rbio = list_entry(table->stripe_cache.next,
+ struct btrfs_raid_bio,
+ stripe_cache);
+ __remove_rbio_from_cache(rbio);
+ }
+ spin_unlock_irqrestore(&table->cache_lock, flags);
+}
+
+/*
+ * remove all cached entries and free the hash table
+ * used by unmount
+ */
+void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
+{
+ if (!info->stripe_hash_table)
+ return;
+ btrfs_clear_rbio_cache(info);
+ kfree(info->stripe_hash_table);
+ info->stripe_hash_table = NULL;
+}
+
+/*
+ * insert an rbio into the stripe cache. It
+ * must have already been prepared by calling
+ * cache_rbio_pages
+ *
+ * If this rbio was already cached, it gets
+ * moved to the front of the lru.
+ *
+ * If the size of the rbio cache is too big, we
+ * prune an item.
+ */
+static void cache_rbio(struct btrfs_raid_bio *rbio)
+{
+ struct btrfs_stripe_hash_table *table;
+ unsigned long flags;
+
+ if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
+ return;
+
+ table = rbio->fs_info->stripe_hash_table;
+
+ spin_lock_irqsave(&table->cache_lock, flags);
+ spin_lock(&rbio->bio_list_lock);
+
+ /* bump our ref if we were not in the list before */
+ if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
+ atomic_inc(&rbio->refs);
+
+ if (!list_empty(&rbio->stripe_cache)){
+ list_move(&rbio->stripe_cache, &table->stripe_cache);
+ } else {
+ list_add(&rbio->stripe_cache, &table->stripe_cache);
+ table->cache_size += 1;
+ }
+
+ spin_unlock(&rbio->bio_list_lock);
+
+ if (table->cache_size > RBIO_CACHE_SIZE) {
+ struct btrfs_raid_bio *found;
+
+ found = list_entry(table->stripe_cache.prev,
+ struct btrfs_raid_bio,
+ stripe_cache);
+
+ if (found != rbio)
+ __remove_rbio_from_cache(found);
+ }
+
+ spin_unlock_irqrestore(&table->cache_lock, flags);
+ return;
+}
+
+/*
+ * helper function to run the xor_blocks api. It is only
+ * able to do MAX_XOR_BLOCKS at a time, so we need to
+ * loop through.
+ */
+static void run_xor(void **pages, int src_cnt, ssize_t len)
+{
+ int src_off = 0;
+ int xor_src_cnt = 0;
+ void *dest = pages[src_cnt];
+
+ while(src_cnt > 0) {
+ xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
+ xor_blocks(xor_src_cnt, len, dest, pages + src_off);
+
+ src_cnt -= xor_src_cnt;
+ src_off += xor_src_cnt;
+ }
+}
+
+/*
+ * returns true if the bio list inside this rbio
+ * covers an entire stripe (no rmw required).
+ * Must be called with the bio list lock held, or
+ * at a time when you know it is impossible to add
+ * new bios into the list
+ */
+static int __rbio_is_full(struct btrfs_raid_bio *rbio)
+{
+ unsigned long size = rbio->bio_list_bytes;
+ int ret = 1;
+
+ if (size != rbio->nr_data * rbio->stripe_len)
+ ret = 0;
+
+ BUG_ON(size > rbio->nr_data * rbio->stripe_len);
+ return ret;
+}
+
+static int rbio_is_full(struct btrfs_raid_bio *rbio)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&rbio->bio_list_lock, flags);
+ ret = __rbio_is_full(rbio);
+ spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
+ return ret;
+}
+
+/*
+ * returns 1 if it is safe to merge two rbios together.
+ * The merging is safe if the two rbios correspond to
+ * the same stripe and if they are both going in the same
+ * direction (read vs write), and if neither one is
+ * locked for final IO
+ *
+ * The caller is responsible for locking such that
+ * rmw_locked is safe to test
+ */
+static int rbio_can_merge(struct btrfs_raid_bio *last,
+ struct btrfs_raid_bio *cur)
+{
+ if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
+ test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
+ return 0;
+
+ /*
+ * we can't merge with cached rbios, since the
+ * idea is that when we merge the destination
+ * rbio is going to run our IO for us. We can
+ * steal from cached rbio's though, other functions
+ * handle that.
+ */
+ if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
+ test_bit(RBIO_CACHE_BIT, &cur->flags))
+ return 0;
+
+ if (last->raid_map[0] !=
+ cur->raid_map[0])
+ return 0;
+
+ /* reads can't merge with writes */
+ if (last->read_rebuild !=
+ cur->read_rebuild) {
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * helper to index into the pstripe
+ */
+static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index)
+{
+ index += (rbio->nr_data * rbio->stripe_len) >> PAGE_CACHE_SHIFT;
+ return rbio->stripe_pages[index];
+}
+
+/*
+ * helper to index into the qstripe, returns null
+ * if there is no qstripe
+ */
+static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index)
+{
+ if (rbio->nr_data + 1 == rbio->bbio->num_stripes)
+ return NULL;
+
+ index += ((rbio->nr_data + 1) * rbio->stripe_len) >>
+ PAGE_CACHE_SHIFT;
+ return rbio->stripe_pages[index];
+}
+
+/*
+ * The first stripe in the table for a logical address
+ * has the lock. rbios are added in one of three ways:
+ *
+ * 1) Nobody has the stripe locked yet. The rbio is given
+ * the lock and 0 is returned. The caller must start the IO
+ * themselves.
+ *
+ * 2) Someone has the stripe locked, but we're able to merge
+ * with the lock owner. The rbio is freed and the IO will
+ * start automatically along with the existing rbio. 1 is returned.
+ *
+ * 3) Someone has the stripe locked, but we're not able to merge.
+ * The rbio is added to the lock owner's plug list, or merged into
+ * an rbio already on the plug list. When the lock owner unlocks,
+ * the next rbio on the list is run and the IO is started automatically.
+ * 1 is returned
+ *
+ * If we return 0, the caller still owns the rbio and must continue with
+ * IO submission. If we return 1, the caller must assume the rbio has
+ * already been freed.
+ */
+static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
+{
+ int bucket = rbio_bucket(rbio);
+ struct btrfs_stripe_hash *h = rbio->fs_info->stripe_hash_table->table + bucket;
+ struct btrfs_raid_bio *cur;
+ struct btrfs_raid_bio *pending;
+ unsigned long flags;
+ DEFINE_WAIT(wait);
+ struct btrfs_raid_bio *freeit = NULL;
+ struct btrfs_raid_bio *cache_drop = NULL;
+ int ret = 0;
+ int walk = 0;
+
+ spin_lock_irqsave(&h->lock, flags);
+ list_for_each_entry(cur, &h->hash_list, hash_list) {
+ walk++;
+ if (cur->raid_map[0] == rbio->raid_map[0]) {
+ spin_lock(&cur->bio_list_lock);
+
+ /* can we steal this cached rbio's pages? */
+ if (bio_list_empty(&cur->bio_list) &&
+ list_empty(&cur->plug_list) &&
+ test_bit(RBIO_CACHE_BIT, &cur->flags) &&
+ !test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) {
+ list_del_init(&cur->hash_list);
+ atomic_dec(&cur->refs);
+
+ steal_rbio(cur, rbio);
+ cache_drop = cur;
+ spin_unlock(&cur->bio_list_lock);
+
+ goto lockit;
+ }
+
+ /* can we merge into the lock owner? */
+ if (rbio_can_merge(cur, rbio)) {
+ merge_rbio(cur, rbio);
+ spin_unlock(&cur->bio_list_lock);
+ freeit = rbio;
+ ret = 1;
+ goto out;
+ }
+
+
+ /*
+ * we couldn't merge with the running
+ * rbio, see if we can merge with the
+ * pending ones. We don't have to
+ * check for rmw_locked because there
+ * is no way they are inside finish_rmw
+ * right now
+ */
+ list_for_each_entry(pending, &cur->plug_list,
+ plug_list) {
+ if (rbio_can_merge(pending, rbio)) {
+ merge_rbio(pending, rbio);
+ spin_unlock(&cur->bio_list_lock);
+ freeit = rbio;
+ ret = 1;
+ goto out;
+ }
+ }
+
+ /* no merging, put us on the tail of the plug list,
+ * our rbio will be started with the currently
+ * running rbio unlocks
+ */
+ list_add_tail(&rbio->plug_list, &cur->plug_list);
+ spin_unlock(&cur->bio_list_lock);
+ ret = 1;
+ goto out;
+ }
+ }
+lockit:
+ atomic_inc(&rbio->refs);
+ list_add(&rbio->hash_list, &h->hash_list);
+out:
+ spin_unlock_irqrestore(&h->lock, flags);
+ if (cache_drop)
+ remove_rbio_from_cache(cache_drop);
+ if (freeit)
+ __free_raid_bio(freeit);
+ return ret;
+}
+
+/*
+ * called as rmw or parity rebuild is completed. If the plug list has more
+ * rbios waiting for this stripe, the next one on the list will be started
+ */
+static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
+{
+ int bucket;
+ struct btrfs_stripe_hash *h;
+ unsigned long flags;
+ int keep_cache = 0;
+
+ bucket = rbio_bucket(rbio);
+ h = rbio->fs_info->stripe_hash_table->table + bucket;
+
+ if (list_empty(&rbio->plug_list))
+ cache_rbio(rbio);
+
+ spin_lock_irqsave(&h->lock, flags);
+ spin_lock(&rbio->bio_list_lock);
+
+ if (!list_empty(&rbio->hash_list)) {
+ /*
+ * if we're still cached and there is no other IO
+ * to perform, just leave this rbio here for others
+ * to steal from later
+ */
+ if (list_empty(&rbio->plug_list) &&
+ test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
+ keep_cache = 1;
+ clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
+ BUG_ON(!bio_list_empty(&rbio->bio_list));
+ goto done;
+ }
+
+ list_del_init(&rbio->hash_list);
+ atomic_dec(&rbio->refs);
+
+ /*
+ * we use the plug list to hold all the rbios
+ * waiting for the chance to lock this stripe.
+ * hand the lock over to one of them.
+ */
+ if (!list_empty(&rbio->plug_list)) {
+ struct btrfs_raid_bio *next;
+ struct list_head *head = rbio->plug_list.next;
+
+ next = list_entry(head, struct btrfs_raid_bio,
+ plug_list);
+
+ list_del_init(&rbio->plug_list);
+
+ list_add(&next->hash_list, &h->hash_list);
+ atomic_inc(&next->refs);
+ spin_unlock(&rbio->bio_list_lock);
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ if (next->read_rebuild)
+ async_read_rebuild(next);
+ else {
+ steal_rbio(rbio, next);
+ async_rmw_stripe(next);
+ }
+
+ goto done_nolock;
+ } else if (waitqueue_active(&h->wait)) {
+ spin_unlock(&rbio->bio_list_lock);
+ spin_unlock_irqrestore(&h->lock, flags);
+ wake_up(&h->wait);
+ goto done_nolock;
+ }
+ }
+done:
+ spin_unlock(&rbio->bio_list_lock);
+ spin_unlock_irqrestore(&h->lock, flags);
+
+done_nolock:
+ if (!keep_cache)
+ remove_rbio_from_cache(rbio);
+}
+
+static void __free_raid_bio(struct btrfs_raid_bio *rbio)
+{
+ int i;
+
+ WARN_ON(atomic_read(&rbio->refs) < 0);
+ if (!atomic_dec_and_test(&rbio->refs))
+ return;
+
+ WARN_ON(!list_empty(&rbio->stripe_cache));
+ WARN_ON(!list_empty(&rbio->hash_list));
+ WARN_ON(!bio_list_empty(&rbio->bio_list));
+
+ for (i = 0; i < rbio->nr_pages; i++) {
+ if (rbio->stripe_pages[i]) {
+ __free_page(rbio->stripe_pages[i]);
+ rbio->stripe_pages[i] = NULL;
+ }
+ }
+ kfree(rbio->raid_map);
+ kfree(rbio->bbio);
+ kfree(rbio);
+}
+
+static void free_raid_bio(struct btrfs_raid_bio *rbio)
+{
+ unlock_stripe(rbio);
+ __free_raid_bio(rbio);
+}
+
+/*
+ * this frees the rbio and runs through all the bios in the
+ * bio_list and calls end_io on them
+ */
+static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err, int uptodate)
+{
+ struct bio *cur = bio_list_get(&rbio->bio_list);
+ struct bio *next;
+ free_raid_bio(rbio);
+
+ while (cur) {
+ next = cur->bi_next;
+ cur->bi_next = NULL;
+ if (uptodate)
+ set_bit(BIO_UPTODATE, &cur->bi_flags);
+ bio_endio(cur, err);
+ cur = next;
+ }
+}
+
+/*
+ * end io function used by finish_rmw. When we finally
+ * get here, we've written a full stripe
+ */
+static void raid_write_end_io(struct bio *bio, int err)
+{
+ struct btrfs_raid_bio *rbio = bio->bi_private;
+
+ if (err)
+ fail_bio_stripe(rbio, bio);
+
+ bio_put(bio);
+
+ if (!atomic_dec_and_test(&rbio->bbio->stripes_pending))
+ return;
+
+ err = 0;
+
+ /* OK, we have read all the stripes we need to. */
+ if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors)
+ err = -EIO;
+
+ rbio_orig_end_io(rbio, err, 0);
+ return;
+}
+
+/*
+ * the read/modify/write code wants to use the original bio for
+ * any pages it included, and then use the rbio for everything
+ * else. This function decides if a given index (stripe number)
+ * and page number in that stripe fall inside the original bio
+ * or the rbio.
+ *
+ * if you set bio_list_only, you'll get a NULL back for any ranges
+ * that are outside the bio_list
+ *
+ * This doesn't take any refs on anything, you get a bare page pointer
+ * and the caller must bump refs as required.
+ *
+ * You must call index_rbio_pages once before you can trust
+ * the answers from this function.
+ */
+static struct page *page_in_rbio(struct btrfs_raid_bio *rbio,
+ int index, int pagenr, int bio_list_only)
+{
+ int chunk_page;
+ struct page *p = NULL;
+
+ chunk_page = index * (rbio->stripe_len >> PAGE_SHIFT) + pagenr;
+
+ spin_lock_irq(&rbio->bio_list_lock);
+ p = rbio->bio_pages[chunk_page];
+ spin_unlock_irq(&rbio->bio_list_lock);
+
+ if (p || bio_list_only)
+ return p;
+
+ return rbio->stripe_pages[chunk_page];
+}
+
+/*
+ * number of pages we need for the entire stripe across all the
+ * drives
+ */
+static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes)
+{
+ unsigned long nr = stripe_len * nr_stripes;
+ return (nr + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+}
+
+/*
+ * allocation and initial setup for the btrfs_raid_bio. Not
+ * this does not allocate any pages for rbio->pages.
+ */
+static struct btrfs_raid_bio *alloc_rbio(struct btrfs_root *root,
+ struct btrfs_bio *bbio, u64 *raid_map,
+ u64 stripe_len)
+{
+ struct btrfs_raid_bio *rbio;
+ int nr_data = 0;
+ int num_pages = rbio_nr_pages(stripe_len, bbio->num_stripes);
+ void *p;
+
+ rbio = kzalloc(sizeof(*rbio) + num_pages * sizeof(struct page *) * 2,
+ GFP_NOFS);
+ if (!rbio) {
+ kfree(raid_map);
+ kfree(bbio);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ bio_list_init(&rbio->bio_list);
+ INIT_LIST_HEAD(&rbio->plug_list);
+ spin_lock_init(&rbio->bio_list_lock);
+ INIT_LIST_HEAD(&rbio->stripe_cache);
+ INIT_LIST_HEAD(&rbio->hash_list);
+ rbio->bbio = bbio;
+ rbio->raid_map = raid_map;
+ rbio->fs_info = root->fs_info;
+ rbio->stripe_len = stripe_len;
+ rbio->nr_pages = num_pages;
+ rbio->faila = -1;
+ rbio->failb = -1;
+ atomic_set(&rbio->refs, 1);
+
+ /*
+ * the stripe_pages and bio_pages array point to the extra
+ * memory we allocated past the end of the rbio
+ */
+ p = rbio + 1;
+ rbio->stripe_pages = p;
+ rbio->bio_pages = p + sizeof(struct page *) * num_pages;
+
+ if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
+ nr_data = bbio->num_stripes - 2;
+ else
+ nr_data = bbio->num_stripes - 1;
+
+ rbio->nr_data = nr_data;
+ return rbio;
+}
+
+/* allocate pages for all the stripes in the bio, including parity */
+static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
+{
+ int i;
+ struct page *page;
+
+ for (i = 0; i < rbio->nr_pages; i++) {
+ if (rbio->stripe_pages[i])
+ continue;
+ page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (!page)
+ return -ENOMEM;
+ rbio->stripe_pages[i] = page;
+ ClearPageUptodate(page);
+ }
+ return 0;
+}
+
+/* allocate pages for just the p/q stripes */
+static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
+{
+ int i;
+ struct page *page;
+
+ i = (rbio->nr_data * rbio->stripe_len) >> PAGE_CACHE_SHIFT;
+
+ for (; i < rbio->nr_pages; i++) {
+ if (rbio->stripe_pages[i])
+ continue;
+ page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (!page)
+ return -ENOMEM;
+ rbio->stripe_pages[i] = page;
+ }
+ return 0;
+}
+
+/*
+ * add a single page from a specific stripe into our list of bios for IO
+ * this will try to merge into existing bios if possible, and returns
+ * zero if all went well.
+ */
+int rbio_add_io_page(struct btrfs_raid_bio *rbio,
+ struct bio_list *bio_list,
+ struct page *page,
+ int stripe_nr,
+ unsigned long page_index,
+ unsigned long bio_max_len)
+{
+ struct bio *last = bio_list->tail;
+ u64 last_end = 0;
+ int ret;
+ struct bio *bio;
+ struct btrfs_bio_stripe *stripe;
+ u64 disk_start;
+
+ stripe = &rbio->bbio->stripes[stripe_nr];
+ disk_start = stripe->physical + (page_index << PAGE_CACHE_SHIFT);
+
+ /* if the device is missing, just fail this stripe */
+ if (!stripe->dev->bdev)
+ return fail_rbio_index(rbio, stripe_nr);
+
+ /* see if we can add this page onto our existing bio */
+ if (last) {
+ last_end = (u64)last->bi_sector << 9;
+ last_end += last->bi_size;
+
+ /*
+ * we can't merge these if they are from different
+ * devices or if they are not contiguous
+ */
+ if (last_end == disk_start && stripe->dev->bdev &&
+ test_bit(BIO_UPTODATE, &last->bi_flags) &&
+ last->bi_bdev == stripe->dev->bdev) {
+ ret = bio_add_page(last, page, PAGE_CACHE_SIZE, 0);
+ if (ret == PAGE_CACHE_SIZE)
+ return 0;
+ }
+ }
+
+ /* put a new bio on the list */
+ bio = bio_alloc(GFP_NOFS, bio_max_len >> PAGE_SHIFT?:1);
+ if (!bio)
+ return -ENOMEM;
+
+ bio->bi_size = 0;
+ bio->bi_bdev = stripe->dev->bdev;
+ bio->bi_sector = disk_start >> 9;
+ set_bit(BIO_UPTODATE, &bio->bi_flags);
+
+ bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
+ bio_list_add(bio_list, bio);
+ return 0;
+}
+
+/*
+ * while we're doing the read/modify/write cycle, we could
+ * have errors in reading pages off the disk. This checks
+ * for errors and if we're not able to read the page it'll
+ * trigger parity reconstruction. The rmw will be finished
+ * after we've reconstructed the failed stripes
+ */
+static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio)
+{
+ if (rbio->faila >= 0 || rbio->failb >= 0) {
+ BUG_ON(rbio->faila == rbio->bbio->num_stripes - 1);
+ __raid56_parity_recover(rbio);
+ } else {
+ finish_rmw(rbio);
+ }
+}
+
+/*
+ * these are just the pages from the rbio array, not from anything
+ * the FS sent down to us
+ */
+static struct page *rbio_stripe_page(struct btrfs_raid_bio *rbio, int stripe, int page)
+{
+ int index;
+ index = stripe * (rbio->stripe_len >> PAGE_CACHE_SHIFT);
+ index += page;
+ return rbio->stripe_pages[index];
+}
+
+/*
+ * helper function to walk our bio list and populate the bio_pages array with
+ * the result. This seems expensive, but it is faster than constantly
+ * searching through the bio list as we setup the IO in finish_rmw or stripe
+ * reconstruction.
+ *
+ * This must be called before you trust the answers from page_in_rbio
+ */
+static void index_rbio_pages(struct btrfs_raid_bio *rbio)
+{
+ struct bio *bio;
+ u64 start;
+ unsigned long stripe_offset;
+ unsigned long page_index;
+ struct page *p;
+ int i;
+
+ spin_lock_irq(&rbio->bio_list_lock);
+ bio_list_for_each(bio, &rbio->bio_list) {
+ start = (u64)bio->bi_sector << 9;
+ stripe_offset = start - rbio->raid_map[0];
+ page_index = stripe_offset >> PAGE_CACHE_SHIFT;
+
+ for (i = 0; i < bio->bi_vcnt; i++) {
+ p = bio->bi_io_vec[i].bv_page;
+ rbio->bio_pages[page_index + i] = p;
+ }
+ }
+ spin_unlock_irq(&rbio->bio_list_lock);
+}
+
+/*
+ * this is called from one of two situations. We either
+ * have a full stripe from the higher layers, or we've read all
+ * the missing bits off disk.
+ *
+ * This will calculate the parity and then send down any
+ * changed blocks.
+ */
+static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
+{
+ struct btrfs_bio *bbio = rbio->bbio;
+ void *pointers[bbio->num_stripes];
+ int stripe_len = rbio->stripe_len;
+ int nr_data = rbio->nr_data;
+ int stripe;
+ int pagenr;
+ int p_stripe = -1;
+ int q_stripe = -1;
+ struct bio_list bio_list;
+ struct bio *bio;
+ int pages_per_stripe = stripe_len >> PAGE_CACHE_SHIFT;
+ int ret;
+
+ bio_list_init(&bio_list);
+
+ if (bbio->num_stripes - rbio->nr_data == 1) {
+ p_stripe = bbio->num_stripes - 1;
+ } else if (bbio->num_stripes - rbio->nr_data == 2) {
+ p_stripe = bbio->num_stripes - 2;
+ q_stripe = bbio->num_stripes - 1;
+ } else {
+ BUG();
+ }
+
+ /* at this point we either have a full stripe,
+ * or we've read the full stripe from the drive.
+ * recalculate the parity and write the new results.
+ *
+ * We're not allowed to add any new bios to the
+ * bio list here, anyone else that wants to
+ * change this stripe needs to do their own rmw.
+ */
+ spin_lock_irq(&rbio->bio_list_lock);
+ set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
+ spin_unlock_irq(&rbio->bio_list_lock);
+
+ atomic_set(&rbio->bbio->error, 0);
+
+ /*
+ * now that we've set rmw_locked, run through the
+ * bio list one last time and map the page pointers
+ *
+ * We don't cache full rbios because we're assuming
+ * the higher layers are unlikely to use this area of
+ * the disk again soon. If they do use it again,
+ * hopefully they will send another full bio.
+ */
+ index_rbio_pages(rbio);
+ if (!rbio_is_full(rbio))
+ cache_rbio_pages(rbio);
+ else
+ clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
+
+ for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) {
+ struct page *p;
+ /* first collect one page from each data stripe */
+ for (stripe = 0; stripe < nr_data; stripe++) {
+ p = page_in_rbio(rbio, stripe, pagenr, 0);
+ pointers[stripe] = kmap(p);
+ }
+
+ /* then add the parity stripe */
+ p = rbio_pstripe_page(rbio, pagenr);
+ SetPageUptodate(p);
+ pointers[stripe++] = kmap(p);
+
+ if (q_stripe != -1) {
+
+ /*
+ * raid6, add the qstripe and call the
+ * library function to fill in our p/q
+ */
+ p = rbio_qstripe_page(rbio, pagenr);
+ SetPageUptodate(p);
+ pointers[stripe++] = kmap(p);
+
+ raid6_call.gen_syndrome(bbio->num_stripes, PAGE_SIZE,
+ pointers);
+ } else {
+ /* raid5 */
+ memcpy(pointers[nr_data], pointers[0], PAGE_SIZE);
+ run_xor(pointers + 1, nr_data - 1, PAGE_CACHE_SIZE);
+ }
+
+
+ for (stripe = 0; stripe < bbio->num_stripes; stripe++)
+ kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
+ }
+
+ /*
+ * time to start writing. Make bios for everything from the
+ * higher layers (the bio_list in our rbio) and our p/q. Ignore
+ * everything else.
+ */
+ for (stripe = 0; stripe < bbio->num_stripes; stripe++) {
+ for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) {
+ struct page *page;
+ if (stripe < rbio->nr_data) {
+ page = page_in_rbio(rbio, stripe, pagenr, 1);
+ if (!page)
+ continue;
+ } else {
+ page = rbio_stripe_page(rbio, stripe, pagenr);
+ }
+
+ ret = rbio_add_io_page(rbio, &bio_list,
+ page, stripe, pagenr, rbio->stripe_len);
+ if (ret)
+ goto cleanup;
+ }
+ }
+
+ atomic_set(&bbio->stripes_pending, bio_list_size(&bio_list));
+ BUG_ON(atomic_read(&bbio->stripes_pending) == 0);
+
+ while (1) {
+ bio = bio_list_pop(&bio_list);
+ if (!bio)
+ break;
+
+ bio->bi_private = rbio;
+ bio->bi_end_io = raid_write_end_io;
+ BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags));
+ submit_bio(WRITE, bio);
+ }
+ return;
+
+cleanup:
+ rbio_orig_end_io(rbio, -EIO, 0);
+}
+
+/*
+ * helper to find the stripe number for a given bio. Used to figure out which
+ * stripe has failed. This expects the bio to correspond to a physical disk,
+ * so it looks up based on physical sector numbers.
+ */
+static int find_bio_stripe(struct btrfs_raid_bio *rbio,
+ struct bio *bio)
+{
+ u64 physical = bio->bi_sector;
+ u64 stripe_start;
+ int i;
+ struct btrfs_bio_stripe *stripe;
+
+ physical <<= 9;
+
+ for (i = 0; i < rbio->bbio->num_stripes; i++) {
+ stripe = &rbio->bbio->stripes[i];
+ stripe_start = stripe->physical;
+ if (physical >= stripe_start &&
+ physical < stripe_start + rbio->stripe_len) {
+ return i;
+ }
+ }
+ return -1;
+}
+
+/*
+ * helper to find the stripe number for a given
+ * bio (before mapping). Used to figure out which stripe has
+ * failed. This looks up based on logical block numbers.
+ */
+static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
+ struct bio *bio)
+{
+ u64 logical = bio->bi_sector;
+ u64 stripe_start;
+ int i;
+
+ logical <<= 9;
+
+ for (i = 0; i < rbio->nr_data; i++) {
+ stripe_start = rbio->raid_map[i];
+ if (logical >= stripe_start &&
+ logical < stripe_start + rbio->stripe_len) {
+ return i;
+ }
+ }
+ return -1;
+}
+
+/*
+ * returns -EIO if we had too many failures
+ */
+static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&rbio->bio_list_lock, flags);
+
+ /* we already know this stripe is bad, move on */
+ if (rbio->faila == failed || rbio->failb == failed)
+ goto out;
+
+ if (rbio->faila == -1) {
+ /* first failure on this rbio */
+ rbio->faila = failed;
+ atomic_inc(&rbio->bbio->error);
+ } else if (rbio->failb == -1) {
+ /* second failure on this rbio */
+ rbio->failb = failed;
+ atomic_inc(&rbio->bbio->error);
+ } else {
+ ret = -EIO;
+ }
+out:
+ spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
+
+ return ret;
+}
+
+/*
+ * helper to fail a stripe based on a physical disk
+ * bio.
+ */
+static int fail_bio_stripe(struct btrfs_raid_bio *rbio,
+ struct bio *bio)
+{
+ int failed = find_bio_stripe(rbio, bio);
+
+ if (failed < 0)
+ return -EIO;
+
+ return fail_rbio_index(rbio, failed);
+}
+
+/*
+ * this sets each page in the bio uptodate. It should only be used on private
+ * rbio pages, nothing that comes in from the higher layers
+ */
+static void set_bio_pages_uptodate(struct bio *bio)
+{
+ int i;
+ struct page *p;
+
+ for (i = 0; i < bio->bi_vcnt; i++) {
+ p = bio->bi_io_vec[i].bv_page;
+ SetPageUptodate(p);
+ }
+}
+
+/*
+ * end io for the read phase of the rmw cycle. All the bios here are physical
+ * stripe bios we've read from the disk so we can recalculate the parity of the
+ * stripe.
+ *
+ * This will usually kick off finish_rmw once all the bios are read in, but it
+ * may trigger parity reconstruction if we had any errors along the way
+ */
+static void raid_rmw_end_io(struct bio *bio, int err)
+{
+ struct btrfs_raid_bio *rbio = bio->bi_private;
+
+ if (err)
+ fail_bio_stripe(rbio, bio);
+ else
+ set_bio_pages_uptodate(bio);
+
+ bio_put(bio);
+
+ if (!atomic_dec_and_test(&rbio->bbio->stripes_pending))
+ return;
+
+ err = 0;
+ if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors)
+ goto cleanup;
+
+ /*
+ * this will normally call finish_rmw to start our write
+ * but if there are any failed stripes we'll reconstruct
+ * from parity first
+ */
+ validate_rbio_for_rmw(rbio);
+ return;
+
+cleanup:
+
+ rbio_orig_end_io(rbio, -EIO, 0);
+}
+
+static void async_rmw_stripe(struct btrfs_raid_bio *rbio)
+{
+ rbio->work.flags = 0;
+ rbio->work.func = rmw_work;
+
+ btrfs_queue_worker(&rbio->fs_info->rmw_workers,
+ &rbio->work);
+}
+
+static void async_read_rebuild(struct btrfs_raid_bio *rbio)
+{
+ rbio->work.flags = 0;
+ rbio->work.func = read_rebuild_work;
+
+ btrfs_queue_worker(&rbio->fs_info->rmw_workers,
+ &rbio->work);
+}
+
+/*
+ * the stripe must be locked by the caller. It will
+ * unlock after all the writes are done
+ */
+static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio)
+{
+ int bios_to_read = 0;
+ struct btrfs_bio *bbio = rbio->bbio;
+ struct bio_list bio_list;
+ int ret;
+ int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int pagenr;
+ int stripe;
+ struct bio *bio;
+
+ bio_list_init(&bio_list);
+
+ ret = alloc_rbio_pages(rbio);
+ if (ret)
+ goto cleanup;
+
+ index_rbio_pages(rbio);
+
+ atomic_set(&rbio->bbio->error, 0);
+ /*
+ * build a list of bios to read all the missing parts of this
+ * stripe
+ */
+ for (stripe = 0; stripe < rbio->nr_data; stripe++) {
+ for (pagenr = 0; pagenr < nr_pages; pagenr++) {
+ struct page *page;
+ /*
+ * we want to find all the pages missing from
+ * the rbio and read them from the disk. If
+ * page_in_rbio finds a page in the bio list
+ * we don't need to read it off the stripe.
+ */
+ page = page_in_rbio(rbio, stripe, pagenr, 1);
+ if (page)
+ continue;
+
+ page = rbio_stripe_page(rbio, stripe, pagenr);
+ /*
+ * the bio cache may have handed us an uptodate
+ * page. If so, be happy and use it
+ */
+ if (PageUptodate(page))
+ continue;
+
+ ret = rbio_add_io_page(rbio, &bio_list, page,
+ stripe, pagenr, rbio->stripe_len);
+ if (ret)
+ goto cleanup;
+ }
+ }
+
+ bios_to_read = bio_list_size(&bio_list);
+ if (!bios_to_read) {
+ /*
+ * this can happen if others have merged with
+ * us, it means there is nothing left to read.
+ * But if there are missing devices it may not be
+ * safe to do the full stripe write yet.
+ */
+ goto finish;
+ }
+
+ /*
+ * the bbio may be freed once we submit the last bio. Make sure
+ * not to touch it after that
+ */
+ atomic_set(&bbio->stripes_pending, bios_to_read);
+ while (1) {
+ bio = bio_list_pop(&bio_list);
+ if (!bio)
+ break;
+
+ bio->bi_private = rbio;
+ bio->bi_end_io = raid_rmw_end_io;
+
+ btrfs_bio_wq_end_io(rbio->fs_info, bio,
+ BTRFS_WQ_ENDIO_RAID56);
+
+ BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags));
+ submit_bio(READ, bio);
+ }
+ /* the actual write will happen once the reads are done */
+ return 0;
+
+cleanup:
+ rbio_orig_end_io(rbio, -EIO, 0);
+ return -EIO;
+
+finish:
+ validate_rbio_for_rmw(rbio);
+ return 0;
+}
+
+/*
+ * if the upper layers pass in a full stripe, we thank them by only allocating
+ * enough pages to hold the parity, and sending it all down quickly.
+ */
+static int full_stripe_write(struct btrfs_raid_bio *rbio)
+{
+ int ret;
+
+ ret = alloc_rbio_parity_pages(rbio);
+ if (ret)
+ return ret;
+
+ ret = lock_stripe_add(rbio);
+ if (ret == 0)
+ finish_rmw(rbio);
+ return 0;
+}
+
+/*
+ * partial stripe writes get handed over to async helpers.
+ * We're really hoping to merge a few more writes into this
+ * rbio before calculating new parity
+ */
+static int partial_stripe_write(struct btrfs_raid_bio *rbio)
+{
+ int ret;
+
+ ret = lock_stripe_add(rbio);
+ if (ret == 0)
+ async_rmw_stripe(rbio);
+ return 0;
+}
+
+/*
+ * sometimes while we were reading from the drive to
+ * recalculate parity, enough new bios come into create
+ * a full stripe. So we do a check here to see if we can
+ * go directly to finish_rmw
+ */
+static int __raid56_parity_write(struct btrfs_raid_bio *rbio)
+{
+ /* head off into rmw land if we don't have a full stripe */
+ if (!rbio_is_full(rbio))
+ return partial_stripe_write(rbio);
+ return full_stripe_write(rbio);
+}
+
+/*
+ * We use plugging call backs to collect full stripes.
+ * Any time we get a partial stripe write while plugged
+ * we collect it into a list. When the unplug comes down,
+ * we sort the list by logical block number and merge
+ * everything we can into the same rbios
+ */
+struct btrfs_plug_cb {
+ struct blk_plug_cb cb;
+ struct btrfs_fs_info *info;
+ struct list_head rbio_list;
+ struct btrfs_work work;
+};
+
+/*
+ * rbios on the plug list are sorted for easier merging.
+ */
+static int plug_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
+ plug_list);
+ struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
+ plug_list);
+ u64 a_sector = ra->bio_list.head->bi_sector;
+ u64 b_sector = rb->bio_list.head->bi_sector;
+
+ if (a_sector < b_sector)
+ return -1;
+ if (a_sector > b_sector)
+ return 1;
+ return 0;
+}
+
+static void run_plug(struct btrfs_plug_cb *plug)
+{
+ struct btrfs_raid_bio *cur;
+ struct btrfs_raid_bio *last = NULL;
+
+ /*
+ * sort our plug list then try to merge
+ * everything we can in hopes of creating full
+ * stripes.
+ */
+ list_sort(NULL, &plug->rbio_list, plug_cmp);
+ while (!list_empty(&plug->rbio_list)) {
+ cur = list_entry(plug->rbio_list.next,
+ struct btrfs_raid_bio, plug_list);
+ list_del_init(&cur->plug_list);
+
+ if (rbio_is_full(cur)) {
+ /* we have a full stripe, send it down */
+ full_stripe_write(cur);
+ continue;
+ }
+ if (last) {
+ if (rbio_can_merge(last, cur)) {
+ merge_rbio(last, cur);
+ __free_raid_bio(cur);
+ continue;
+
+ }
+ __raid56_parity_write(last);
+ }
+ last = cur;
+ }
+ if (last) {
+ __raid56_parity_write(last);
+ }
+ kfree(plug);
+}
+
+/*
+ * if the unplug comes from schedule, we have to push the
+ * work off to a helper thread
+ */
+static void unplug_work(struct btrfs_work *work)
+{
+ struct btrfs_plug_cb *plug;
+ plug = container_of(work, struct btrfs_plug_cb, work);
+ run_plug(plug);
+}
+
+static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
+{
+ struct btrfs_plug_cb *plug;
+ plug = container_of(cb, struct btrfs_plug_cb, cb);
+
+ if (from_schedule) {
+ plug->work.flags = 0;
+ plug->work.func = unplug_work;
+ btrfs_queue_worker(&plug->info->rmw_workers,
+ &plug->work);
+ return;
+ }
+ run_plug(plug);
+}
+
+/*
+ * our main entry point for writes from the rest of the FS.
+ */
+int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
+ struct btrfs_bio *bbio, u64 *raid_map,
+ u64 stripe_len)
+{
+ struct btrfs_raid_bio *rbio;
+ struct btrfs_plug_cb *plug = NULL;
+ struct blk_plug_cb *cb;
+
+ rbio = alloc_rbio(root, bbio, raid_map, stripe_len);
+ if (IS_ERR(rbio)) {
+ kfree(raid_map);
+ kfree(bbio);
+ return PTR_ERR(rbio);
+ }
+ bio_list_add(&rbio->bio_list, bio);
+ rbio->bio_list_bytes = bio->bi_size;
+
+ /*
+ * don't plug on full rbios, just get them out the door
+ * as quickly as we can
+ */
+ if (rbio_is_full(rbio))
+ return full_stripe_write(rbio);
+
+ cb = blk_check_plugged(btrfs_raid_unplug, root->fs_info,
+ sizeof(*plug));
+ if (cb) {
+ plug = container_of(cb, struct btrfs_plug_cb, cb);
+ if (!plug->info) {
+ plug->info = root->fs_info;
+ INIT_LIST_HEAD(&plug->rbio_list);
+ }
+ list_add_tail(&rbio->plug_list, &plug->rbio_list);
+ } else {
+ return __raid56_parity_write(rbio);
+ }
+ return 0;
+}
+
+/*
+ * all parity reconstruction happens here. We've read in everything
+ * we can find from the drives and this does the heavy lifting of
+ * sorting the good from the bad.
+ */
+static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
+{
+ int pagenr, stripe;
+ void **pointers;
+ int faila = -1, failb = -1;
+ int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ struct page *page;
+ int err;
+ int i;
+
+ pointers = kzalloc(rbio->bbio->num_stripes * sizeof(void *),
+ GFP_NOFS);
+ if (!pointers) {
+ err = -ENOMEM;
+ goto cleanup_io;
+ }
+
+ faila = rbio->faila;
+ failb = rbio->failb;
+
+ if (rbio->read_rebuild) {
+ spin_lock_irq(&rbio->bio_list_lock);
+ set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
+ spin_unlock_irq(&rbio->bio_list_lock);
+ }
+
+ index_rbio_pages(rbio);
+
+ for (pagenr = 0; pagenr < nr_pages; pagenr++) {
+ /* setup our array of pointers with pages
+ * from each stripe
+ */
+ for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) {
+ /*
+ * if we're rebuilding a read, we have to use
+ * pages from the bio list
+ */
+ if (rbio->read_rebuild &&
+ (stripe == faila || stripe == failb)) {
+ page = page_in_rbio(rbio, stripe, pagenr, 0);
+ } else {
+ page = rbio_stripe_page(rbio, stripe, pagenr);
+ }
+ pointers[stripe] = kmap(page);
+ }
+
+ /* all raid6 handling here */
+ if (rbio->raid_map[rbio->bbio->num_stripes - 1] ==
+ RAID6_Q_STRIPE) {
+
+ /*
+ * single failure, rebuild from parity raid5
+ * style
+ */
+ if (failb < 0) {
+ if (faila == rbio->nr_data) {
+ /*
+ * Just the P stripe has failed, without
+ * a bad data or Q stripe.
+ * TODO, we should redo the xor here.
+ */
+ err = -EIO;
+ goto cleanup;
+ }
+ /*
+ * a single failure in raid6 is rebuilt
+ * in the pstripe code below
+ */
+ goto pstripe;
+ }
+
+ /* make sure our ps and qs are in order */
+ if (faila > failb) {
+ int tmp = failb;
+ failb = faila;
+ faila = tmp;
+ }
+
+ /* if the q stripe is failed, do a pstripe reconstruction
+ * from the xors.
+ * If both the q stripe and the P stripe are failed, we're
+ * here due to a crc mismatch and we can't give them the
+ * data they want
+ */
+ if (rbio->raid_map[failb] == RAID6_Q_STRIPE) {
+ if (rbio->raid_map[faila] == RAID5_P_STRIPE) {
+ err = -EIO;
+ goto cleanup;
+ }
+ /*
+ * otherwise we have one bad data stripe and
+ * a good P stripe. raid5!
+ */
+ goto pstripe;
+ }
+
+ if (rbio->raid_map[failb] == RAID5_P_STRIPE) {
+ raid6_datap_recov(rbio->bbio->num_stripes,
+ PAGE_SIZE, faila, pointers);
+ } else {
+ raid6_2data_recov(rbio->bbio->num_stripes,
+ PAGE_SIZE, faila, failb,
+ pointers);
+ }
+ } else {
+ void *p;
+
+ /* rebuild from P stripe here (raid5 or raid6) */
+ BUG_ON(failb != -1);
+pstripe:
+ /* Copy parity block into failed block to start with */
+ memcpy(pointers[faila],
+ pointers[rbio->nr_data],
+ PAGE_CACHE_SIZE);
+
+ /* rearrange the pointer array */
+ p = pointers[faila];
+ for (stripe = faila; stripe < rbio->nr_data - 1; stripe++)
+ pointers[stripe] = pointers[stripe + 1];
+ pointers[rbio->nr_data - 1] = p;
+
+ /* xor in the rest */
+ run_xor(pointers, rbio->nr_data - 1, PAGE_CACHE_SIZE);
+ }
+ /* if we're doing this rebuild as part of an rmw, go through
+ * and set all of our private rbio pages in the
+ * failed stripes as uptodate. This way finish_rmw will
+ * know they can be trusted. If this was a read reconstruction,
+ * other endio functions will fiddle the uptodate bits
+ */
+ if (!rbio->read_rebuild) {
+ for (i = 0; i < nr_pages; i++) {
+ if (faila != -1) {
+ page = rbio_stripe_page(rbio, faila, i);
+ SetPageUptodate(page);
+ }
+ if (failb != -1) {
+ page = rbio_stripe_page(rbio, failb, i);
+ SetPageUptodate(page);
+ }
+ }
+ }
+ for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) {
+ /*
+ * if we're rebuilding a read, we have to use
+ * pages from the bio list
+ */
+ if (rbio->read_rebuild &&
+ (stripe == faila || stripe == failb)) {
+ page = page_in_rbio(rbio, stripe, pagenr, 0);
+ } else {
+ page = rbio_stripe_page(rbio, stripe, pagenr);
+ }
+ kunmap(page);
+ }
+ }
+
+ err = 0;
+cleanup:
+ kfree(pointers);
+
+cleanup_io:
+
+ if (rbio->read_rebuild) {
+ if (err == 0)
+ cache_rbio_pages(rbio);
+ else
+ clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
+
+ rbio_orig_end_io(rbio, err, err == 0);
+ } else if (err == 0) {
+ rbio->faila = -1;
+ rbio->failb = -1;
+ finish_rmw(rbio);
+ } else {
+ rbio_orig_end_io(rbio, err, 0);
+ }
+}
+
+/*
+ * This is called only for stripes we've read from disk to
+ * reconstruct the parity.
+ */
+static void raid_recover_end_io(struct bio *bio, int err)
+{
+ struct btrfs_raid_bio *rbio = bio->bi_private;
+
+ /*
+ * we only read stripe pages off the disk, set them
+ * up to date if there were no errors
+ */
+ if (err)
+ fail_bio_stripe(rbio, bio);
+ else
+ set_bio_pages_uptodate(bio);
+ bio_put(bio);
+
+ if (!atomic_dec_and_test(&rbio->bbio->stripes_pending))
+ return;
+
+ if (atomic_read(&rbio->bbio->error) > rbio->bbio->max_errors)
+ rbio_orig_end_io(rbio, -EIO, 0);
+ else
+ __raid_recover_end_io(rbio);
+}
+
+/*
+ * reads everything we need off the disk to reconstruct
+ * the parity. endio handlers trigger final reconstruction
+ * when the IO is done.
+ *
+ * This is used both for reads from the higher layers and for
+ * parity construction required to finish a rmw cycle.
+ */
+static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
+{
+ int bios_to_read = 0;
+ struct btrfs_bio *bbio = rbio->bbio;
+ struct bio_list bio_list;
+ int ret;
+ int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int pagenr;
+ int stripe;
+ struct bio *bio;
+
+ bio_list_init(&bio_list);
+
+ ret = alloc_rbio_pages(rbio);
+ if (ret)
+ goto cleanup;
+
+ atomic_set(&rbio->bbio->error, 0);
+
+ /*
+ * read everything that hasn't failed. Thanks to the
+ * stripe cache, it is possible that some or all of these
+ * pages are going to be uptodate.
+ */
+ for (stripe = 0; stripe < bbio->num_stripes; stripe++) {
+ if (rbio->faila == stripe ||
+ rbio->failb == stripe)
+ continue;
+
+ for (pagenr = 0; pagenr < nr_pages; pagenr++) {
+ struct page *p;
+
+ /*
+ * the rmw code may have already read this
+ * page in
+ */
+ p = rbio_stripe_page(rbio, stripe, pagenr);
+ if (PageUptodate(p))
+ continue;
+
+ ret = rbio_add_io_page(rbio, &bio_list,
+ rbio_stripe_page(rbio, stripe, pagenr),
+ stripe, pagenr, rbio->stripe_len);
+ if (ret < 0)
+ goto cleanup;
+ }
+ }
+
+ bios_to_read = bio_list_size(&bio_list);
+ if (!bios_to_read) {
+ /*
+ * we might have no bios to read just because the pages
+ * were up to date, or we might have no bios to read because
+ * the devices were gone.
+ */
+ if (atomic_read(&rbio->bbio->error) <= rbio->bbio->max_errors) {
+ __raid_recover_end_io(rbio);
+ goto out;
+ } else {
+ goto cleanup;
+ }
+ }
+
+ /*
+ * the bbio may be freed once we submit the last bio. Make sure
+ * not to touch it after that
+ */
+ atomic_set(&bbio->stripes_pending, bios_to_read);
+ while (1) {
+ bio = bio_list_pop(&bio_list);
+ if (!bio)
+ break;
+
+ bio->bi_private = rbio;
+ bio->bi_end_io = raid_recover_end_io;
+
+ btrfs_bio_wq_end_io(rbio->fs_info, bio,
+ BTRFS_WQ_ENDIO_RAID56);
+
+ BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags));
+ submit_bio(READ, bio);
+ }
+out:
+ return 0;
+
+cleanup:
+ if (rbio->read_rebuild)
+ rbio_orig_end_io(rbio, -EIO, 0);
+ return -EIO;
+}
+
+/*
+ * the main entry point for reads from the higher layers. This
+ * is really only called when the normal read path had a failure,
+ * so we assume the bio they send down corresponds to a failed part
+ * of the drive.
+ */
+int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
+ struct btrfs_bio *bbio, u64 *raid_map,
+ u64 stripe_len, int mirror_num)
+{
+ struct btrfs_raid_bio *rbio;
+ int ret;
+
+ rbio = alloc_rbio(root, bbio, raid_map, stripe_len);
+ if (IS_ERR(rbio)) {
+ return PTR_ERR(rbio);
+ }
+
+ rbio->read_rebuild = 1;
+ bio_list_add(&rbio->bio_list, bio);
+ rbio->bio_list_bytes = bio->bi_size;
+
+ rbio->faila = find_logical_bio_stripe(rbio, bio);
+ if (rbio->faila == -1) {
+ BUG();
+ kfree(rbio);
+ return -EIO;
+ }
+
+ /*
+ * reconstruct from the q stripe if they are
+ * asking for mirror 3
+ */
+ if (mirror_num == 3)
+ rbio->failb = bbio->num_stripes - 2;
+
+ ret = lock_stripe_add(rbio);
+
+ /*
+ * __raid56_parity_recover will end the bio with
+ * any errors it hits. We don't want to return
+ * its error value up the stack because our caller
+ * will end up calling bio_endio with any nonzero
+ * return
+ */
+ if (ret == 0)
+ __raid56_parity_recover(rbio);
+ /*
+ * our rbio has been added to the list of
+ * rbios that will be handled after the
+ * currently lock owner is done
+ */
+ return 0;
+
+}
+
+static void rmw_work(struct btrfs_work *work)
+{
+ struct btrfs_raid_bio *rbio;
+
+ rbio = container_of(work, struct btrfs_raid_bio, work);
+ raid56_rmw_stripe(rbio);
+}
+
+static void read_rebuild_work(struct btrfs_work *work)
+{
+ struct btrfs_raid_bio *rbio;
+
+ rbio = container_of(work, struct btrfs_raid_bio, work);
+ __raid56_parity_recover(rbio);
+}
#include <linux/capability.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
+#include <linux/raid/pq.h>
+#include <asm/div64.h>
#include "compat.h"
#include "ctree.h"
#include "extent_map.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
+#include "raid56.h"
#include "async-thread.h"
#include "check-integrity.h"
#include "rcu-string.h"
goto out;
}
+ if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
+ root->fs_info->fs_devices->rw_devices <= 2) {
+ printk(KERN_ERR "btrfs: unable to go below two "
+ "devices on raid5\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
+ root->fs_info->fs_devices->rw_devices <= 3) {
+ printk(KERN_ERR "btrfs: unable to go below three "
+ "devices on raid6\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
if (strcmp(device_path, "missing") == 0) {
struct list_head *devices;
struct btrfs_device *tmp;
ret = 0;
/* Notify udev that device has changed */
- btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
+ if (bdev)
+ btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
error_brelse:
brelse(bh);
return 0;
if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
- BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
- factor = 2;
- else
- factor = 1;
- factor = num_stripes / factor;
+ BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
+ factor = num_stripes / 2;
+ } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
+ factor = num_stripes - 1;
+ } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
+ factor = num_stripes - 2;
+ } else {
+ factor = num_stripes;
+ }
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
int mixed = 0;
int ret;
u64 num_devices;
+ int cancel = 0;
if (btrfs_fs_closing(fs_info) ||
atomic_read(&fs_info->balance_pause_req) ||
allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
else
allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
- BTRFS_BLOCK_GROUP_RAID10);
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6);
if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(!alloc_profile_is_valid(bctl->data.target, 1) ||
/* allow to reduce meta or sys integrity only if force set */
allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
- BTRFS_BLOCK_GROUP_RAID10;
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6;
+
if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_system_alloc_bits & allowed) &&
!(bctl->sys.target & allowed)) ||
}
if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
- balance_need_close(fs_info)) {
- __cancel_balance(fs_info);
- }
+ balance_need_close(fs_info))
+ cancel = 1;
if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
fs_info->num_tolerated_disk_barrier_failures =
btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
}
+ if (cancel)
+ __cancel_balance(fs_info);
+
wake_up(&fs_info->balance_wait_q);
return ret;
}
struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
+ /*
+ * sub_stripes info for map,
+ * dev_stripes -- stripes per dev, 2 for DUP, 1 other wise
+ * devs_max -- max devices per stripe, 0 for unlimited
+ * devs_min -- min devices per stripe
+ * devs_increment -- ndevs must be a multiple of this
+ * ncopies -- how many copies of the data we have
+ */
{ 2, 1, 0, 4, 2, 2 /* raid10 */ },
{ 1, 1, 2, 2, 2, 2 /* raid1 */ },
{ 1, 2, 1, 1, 1, 2 /* dup */ },
{ 1, 1, 0, 2, 1, 1 /* raid0 */ },
{ 1, 1, 1, 1, 1, 1 /* single */ },
+ { 1, 1, 0, 2, 1, 2 /* raid5 */ },
+ { 1, 1, 0, 3, 1, 3 /* raid6 */ },
};
+static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
+{
+ /* TODO allow them to set a preferred stripe size */
+ return 64 * 1024;
+}
+
+static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
+{
+ u64 features;
+
+ if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
+ return;
+
+ features = btrfs_super_incompat_flags(info->super_copy);
+ if (features & BTRFS_FEATURE_INCOMPAT_RAID56)
+ return;
+
+ features |= BTRFS_FEATURE_INCOMPAT_RAID56;
+ btrfs_set_super_incompat_flags(info->super_copy, features);
+ printk(KERN_INFO "btrfs: setting RAID5/6 feature flag\n");
+}
+
static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct map_lookup **map_ret,
struct btrfs_device_info *devices_info = NULL;
u64 total_avail;
int num_stripes; /* total number of stripes to allocate */
+ int data_stripes; /* number of stripes that count for
+ block group size */
int sub_stripes; /* sub_stripes info for map */
int dev_stripes; /* stripes per dev */
int devs_max; /* max devs to use */
u64 max_chunk_size;
u64 stripe_size;
u64 num_bytes;
+ u64 raid_stripe_len = BTRFS_STRIPE_LEN;
int ndevs;
int i;
int j;
stripe_size = devices_info[ndevs-1].max_avail;
num_stripes = ndevs * dev_stripes;
+ /*
+ * this will have to be fixed for RAID1 and RAID10 over
+ * more drives
+ */
+ data_stripes = num_stripes / ncopies;
+
if (stripe_size * ndevs > max_chunk_size * ncopies) {
stripe_size = max_chunk_size * ncopies;
do_div(stripe_size, ndevs);
}
-
+ if (type & BTRFS_BLOCK_GROUP_RAID5) {
+ raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
+ btrfs_super_stripesize(info->super_copy));
+ data_stripes = num_stripes - 1;
+ }
+ if (type & BTRFS_BLOCK_GROUP_RAID6) {
+ raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
+ btrfs_super_stripesize(info->super_copy));
+ data_stripes = num_stripes - 2;
+ }
do_div(stripe_size, dev_stripes);
/* align to BTRFS_STRIPE_LEN */
- do_div(stripe_size, BTRFS_STRIPE_LEN);
- stripe_size *= BTRFS_STRIPE_LEN;
+ do_div(stripe_size, raid_stripe_len);
+ stripe_size *= raid_stripe_len;
map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
}
}
map->sector_size = extent_root->sectorsize;
- map->stripe_len = BTRFS_STRIPE_LEN;
- map->io_align = BTRFS_STRIPE_LEN;
- map->io_width = BTRFS_STRIPE_LEN;
+ map->stripe_len = raid_stripe_len;
+ map->io_align = raid_stripe_len;
+ map->io_width = raid_stripe_len;
map->type = type;
map->sub_stripes = sub_stripes;
*map_ret = map;
- num_bytes = stripe_size * (num_stripes / ncopies);
+ num_bytes = stripe_size * data_stripes;
*stripe_size_out = stripe_size;
*num_bytes_out = num_bytes;
}
}
+ check_raid56_incompat_flag(extent_root->fs_info, type);
+
kfree(devices_info);
return 0;
ret = map->num_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
ret = map->sub_stripes;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+ ret = 2;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+ ret = 3;
else
ret = 1;
free_extent_map(em);
return ret;
}
+unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
+ struct btrfs_mapping_tree *map_tree,
+ u64 logical)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct extent_map_tree *em_tree = &map_tree->map_tree;
+ unsigned long len = root->sectorsize;
+
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, logical, len);
+ read_unlock(&em_tree->lock);
+ BUG_ON(!em);
+
+ BUG_ON(em->start > logical || em->start + em->len < logical);
+ map = (struct map_lookup *)em->bdev;
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6)) {
+ len = map->stripe_len * nr_data_stripes(map);
+ }
+ free_extent_map(em);
+ return len;
+}
+
+int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
+ u64 logical, u64 len, int mirror_num)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct extent_map_tree *em_tree = &map_tree->map_tree;
+ int ret = 0;
+
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, logical, len);
+ read_unlock(&em_tree->lock);
+ BUG_ON(!em);
+
+ BUG_ON(em->start > logical || em->start + em->len < logical);
+ map = (struct map_lookup *)em->bdev;
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6))
+ ret = 1;
+ free_extent_map(em);
+ return ret;
+}
+
static int find_live_mirror(struct btrfs_fs_info *fs_info,
struct map_lookup *map, int first, int num,
int optimal, int dev_replace_is_ongoing)
return optimal;
}
+static inline int parity_smaller(u64 a, u64 b)
+{
+ return a > b;
+}
+
+/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
+static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
+{
+ struct btrfs_bio_stripe s;
+ int i;
+ u64 l;
+ int again = 1;
+
+ while (again) {
+ again = 0;
+ for (i = 0; i < bbio->num_stripes - 1; i++) {
+ if (parity_smaller(raid_map[i], raid_map[i+1])) {
+ s = bbio->stripes[i];
+ l = raid_map[i];
+ bbio->stripes[i] = bbio->stripes[i+1];
+ raid_map[i] = raid_map[i+1];
+ bbio->stripes[i+1] = s;
+ raid_map[i+1] = l;
+ again = 1;
+ }
+ }
+ }
+}
+
static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret,
- int mirror_num)
+ int mirror_num, u64 **raid_map_ret)
{
struct extent_map *em;
struct map_lookup *map;
u64 stripe_nr;
u64 stripe_nr_orig;
u64 stripe_nr_end;
+ u64 stripe_len;
+ u64 *raid_map = NULL;
int stripe_index;
int i;
int ret = 0;
int num_alloc_stripes;
int patch_the_first_stripe_for_dev_replace = 0;
u64 physical_to_patch_in_first_stripe = 0;
+ u64 raid56_full_stripe_start = (u64)-1;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, *length);
map = (struct map_lookup *)em->bdev;
offset = logical - em->start;
+ if (mirror_num > map->num_stripes)
+ mirror_num = 0;
+
+ stripe_len = map->stripe_len;
stripe_nr = offset;
/*
* stripe_nr counts the total number of stripes we have to stride
* to get to this block
*/
- do_div(stripe_nr, map->stripe_len);
+ do_div(stripe_nr, stripe_len);
- stripe_offset = stripe_nr * map->stripe_len;
+ stripe_offset = stripe_nr * stripe_len;
BUG_ON(offset < stripe_offset);
/* stripe_offset is the offset of this block in its stripe*/
stripe_offset = offset - stripe_offset;
- if (rw & REQ_DISCARD)
+ /* if we're here for raid56, we need to know the stripe aligned start */
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
+ unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
+ raid56_full_stripe_start = offset;
+
+ /* allow a write of a full stripe, but make sure we don't
+ * allow straddling of stripes
+ */
+ do_div(raid56_full_stripe_start, full_stripe_len);
+ raid56_full_stripe_start *= full_stripe_len;
+ }
+
+ if (rw & REQ_DISCARD) {
+ /* we don't discard raid56 yet */
+ if (map->type &
+ (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
*length = min_t(u64, em->len - offset, *length);
- else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
- /* we limit the length of each bio to what fits in a stripe */
- *length = min_t(u64, em->len - offset,
- map->stripe_len - stripe_offset);
+ } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+ u64 max_len;
+ /* For writes to RAID[56], allow a full stripeset across all disks.
+ For other RAID types and for RAID[56] reads, just allow a single
+ stripe (on a single disk). */
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
+ (rw & REQ_WRITE)) {
+ max_len = stripe_len * nr_data_stripes(map) -
+ (offset - raid56_full_stripe_start);
+ } else {
+ /* we limit the length of each bio to what fits in a stripe */
+ max_len = stripe_len - stripe_offset;
+ }
+ *length = min_t(u64, em->len - offset, max_len);
} else {
*length = em->len - offset;
}
+ /* This is for when we're called from btrfs_merge_bio_hook() and all
+ it cares about is the length */
if (!bbio_ret)
goto out;
u64 physical_of_found = 0;
ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
- logical, &tmp_length, &tmp_bbio, 0);
+ logical, &tmp_length, &tmp_bbio, 0, NULL);
if (ret) {
WARN_ON(tmp_bbio != NULL);
goto out;
do_div(stripe_nr_end, map->stripe_len);
stripe_end_offset = stripe_nr_end * map->stripe_len -
(offset + *length);
+
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
if (rw & REQ_DISCARD)
num_stripes = min_t(u64, map->num_stripes,
dev_replace_is_ongoing);
mirror_num = stripe_index - old_stripe_index + 1;
}
+
+ } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6)) {
+ u64 tmp;
+
+ if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
+ && raid_map_ret) {
+ int i, rot;
+
+ /* push stripe_nr back to the start of the full stripe */
+ stripe_nr = raid56_full_stripe_start;
+ do_div(stripe_nr, stripe_len);
+
+ stripe_index = do_div(stripe_nr, nr_data_stripes(map));
+
+ /* RAID[56] write or recovery. Return all stripes */
+ num_stripes = map->num_stripes;
+ max_errors = nr_parity_stripes(map);
+
+ raid_map = kmalloc(sizeof(u64) * num_stripes,
+ GFP_NOFS);
+ if (!raid_map) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Work out the disk rotation on this stripe-set */
+ tmp = stripe_nr;
+ rot = do_div(tmp, num_stripes);
+
+ /* Fill in the logical address of each stripe */
+ tmp = stripe_nr * nr_data_stripes(map);
+ for (i = 0; i < nr_data_stripes(map); i++)
+ raid_map[(i+rot) % num_stripes] =
+ em->start + (tmp + i) * map->stripe_len;
+
+ raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+ raid_map[(i+rot+1) % num_stripes] =
+ RAID6_Q_STRIPE;
+
+ *length = map->stripe_len;
+ stripe_index = 0;
+ stripe_offset = 0;
+ } else {
+ /*
+ * Mirror #0 or #1 means the original data block.
+ * Mirror #2 is RAID5 parity block.
+ * Mirror #3 is RAID6 Q block.
+ */
+ stripe_index = do_div(stripe_nr, nr_data_stripes(map));
+ if (mirror_num > 1)
+ stripe_index = nr_data_stripes(map) +
+ mirror_num - 2;
+
+ /* We distribute the parity blocks across stripes */
+ tmp = stripe_nr + stripe_index;
+ stripe_index = do_div(tmp, map->num_stripes);
+ }
} else {
/*
* after this do_div call, stripe_nr is the number of stripes
if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_DUP)) {
max_errors = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
+ max_errors = 2;
}
}
bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
bbio->mirror_num = map->num_stripes + 1;
}
+ if (raid_map) {
+ sort_parity_stripes(bbio, raid_map);
+ *raid_map_ret = raid_map;
+ }
out:
if (dev_replace_is_ongoing)
btrfs_dev_replace_unlock(dev_replace);
struct btrfs_bio **bbio_ret, int mirror_num)
{
return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
- mirror_num);
+ mirror_num, NULL);
}
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
u64 bytenr;
u64 length;
u64 stripe_nr;
+ u64 rmap_len;
int i, j, nr = 0;
read_lock(&em_tree->lock);
map = (struct map_lookup *)em->bdev;
length = em->len;
+ rmap_len = map->stripe_len;
+
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
do_div(length, map->num_stripes / map->sub_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
do_div(length, map->num_stripes);
+ else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6)) {
+ do_div(length, nr_data_stripes(map));
+ rmap_len = map->stripe_len * nr_data_stripes(map);
+ }
buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
BUG_ON(!buf); /* -ENOMEM */
do_div(stripe_nr, map->sub_stripes);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = stripe_nr * map->num_stripes + i;
- }
- bytenr = chunk_start + stripe_nr * map->stripe_len;
+ } /* else if RAID[56], multiply by nr_data_stripes().
+ * Alternatively, just use rmap_len below instead of
+ * map->stripe_len */
+
+ bytenr = chunk_start + stripe_nr * rmap_len;
WARN_ON(nr >= map->num_stripes);
for (j = 0; j < nr; j++) {
if (buf[j] == bytenr)
*logical = buf;
*naddrs = nr;
- *stripe_len = map->stripe_len;
+ *stripe_len = rmap_len;
free_extent_map(em);
return 0;
bio->bi_bdev = (struct block_device *)
(unsigned long)bbio->mirror_num;
/* only send an error to the higher layers if it is
- * beyond the tolerance of the multi-bio
+ * beyond the tolerance of the btrfs bio
*/
if (atomic_read(&bbio->error) > bbio->max_errors) {
err = -EIO;
* This will add one bio to the pending list for a device and make sure
* the work struct is scheduled.
*/
-static noinline void schedule_bio(struct btrfs_root *root,
+noinline void btrfs_schedule_bio(struct btrfs_root *root,
struct btrfs_device *device,
int rw, struct bio *bio)
{
int should_queue = 1;
struct btrfs_pending_bios *pending_bios;
+ if (device->missing || !device->bdev) {
+ bio_endio(bio, -EIO);
+ return;
+ }
+
/* don't bother with additional async steps for reads, right now */
if (!(rw & REQ_WRITE)) {
bio_get(bio);
#endif
bio->bi_bdev = dev->bdev;
if (async)
- schedule_bio(root, dev, rw, bio);
+ btrfs_schedule_bio(root, dev, rw, bio);
else
btrfsic_submit_bio(rw, bio);
}
u64 logical = (u64)bio->bi_sector << 9;
u64 length = 0;
u64 map_length;
+ u64 *raid_map = NULL;
int ret;
int dev_nr = 0;
int total_devs = 1;
length = bio->bi_size;
map_length = length;
- ret = btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
- mirror_num);
- if (ret)
+ ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
+ mirror_num, &raid_map);
+ if (ret) /* -ENOMEM */
return ret;
total_devs = bbio->num_stripes;
+ bbio->orig_bio = first_bio;
+ bbio->private = first_bio->bi_private;
+ bbio->end_io = first_bio->bi_end_io;
+ atomic_set(&bbio->stripes_pending, bbio->num_stripes);
+
+ if (raid_map) {
+ /* In this case, map_length has been set to the length of
+ a single stripe; not the whole write */
+ if (rw & WRITE) {
+ return raid56_parity_write(root, bio, bbio,
+ raid_map, map_length);
+ } else {
+ return raid56_parity_recover(root, bio, bbio,
+ raid_map, map_length,
+ mirror_num);
+ }
+ }
+
if (map_length < length) {
printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
"len %llu\n", (unsigned long long)logical,
BUG();
}
- bbio->orig_bio = first_bio;
- bbio->private = first_bio->bi_private;
- bbio->end_io = first_bio->bi_end_io;
- atomic_set(&bbio->stripes_pending, bbio->num_stripes);
-
while (dev_nr < total_devs) {
dev = bbio->stripes[dev_nr].dev;
if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
projects / linux-imx.git / commitdiff