![David Sterba](/assets/img/avatar_default.png)
Add fall-back code to catch failure of full_stripe_write. Proper error handling from inside run_plug would need more code restructuring as it's called at arbitrary points by io scheduler. Signed-off-by: David Sterba <dsterba@suse.com>
2745 lines
67 KiB
C
2745 lines
67 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2012 Fusion-io All rights reserved.
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* Copyright (C) 2012 Intel Corp. All rights reserved.
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*/
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#include <linux/sched.h>
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#include <linux/bio.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/raid/pq.h>
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#include <linux/hash.h>
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#include <linux/list_sort.h>
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#include <linux/raid/xor.h>
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#include <linux/mm.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "volumes.h"
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#include "raid56.h"
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#include "async-thread.h"
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/* set when additional merges to this rbio are not allowed */
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#define RBIO_RMW_LOCKED_BIT 1
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/*
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* set when this rbio is sitting in the hash, but it is just a cache
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* of past RMW
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*/
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#define RBIO_CACHE_BIT 2
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/*
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* set when it is safe to trust the stripe_pages for caching
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*/
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#define RBIO_CACHE_READY_BIT 3
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#define RBIO_CACHE_SIZE 1024
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enum btrfs_rbio_ops {
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BTRFS_RBIO_WRITE,
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BTRFS_RBIO_READ_REBUILD,
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BTRFS_RBIO_PARITY_SCRUB,
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BTRFS_RBIO_REBUILD_MISSING,
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};
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struct btrfs_raid_bio {
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struct btrfs_fs_info *fs_info;
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struct btrfs_bio *bbio;
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/* while we're doing rmw on a stripe
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* we put it into a hash table so we can
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* lock the stripe and merge more rbios
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* into it.
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*/
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struct list_head hash_list;
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/*
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* LRU list for the stripe cache
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*/
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struct list_head stripe_cache;
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/*
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* for scheduling work in the helper threads
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*/
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struct btrfs_work work;
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/*
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* bio list and bio_list_lock are used
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* to add more bios into the stripe
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* in hopes of avoiding the full rmw
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*/
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struct bio_list bio_list;
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spinlock_t bio_list_lock;
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/* also protected by the bio_list_lock, the
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* plug list is used by the plugging code
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* to collect partial bios while plugged. The
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* stripe locking code also uses it to hand off
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* the stripe lock to the next pending IO
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*/
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struct list_head plug_list;
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/*
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* flags that tell us if it is safe to
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* merge with this bio
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*/
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unsigned long flags;
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/* size of each individual stripe on disk */
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int stripe_len;
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/* number of data stripes (no p/q) */
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int nr_data;
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int real_stripes;
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int stripe_npages;
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/*
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* set if we're doing a parity rebuild
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* for a read from higher up, which is handled
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* differently from a parity rebuild as part of
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* rmw
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*/
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enum btrfs_rbio_ops operation;
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/* first bad stripe */
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int faila;
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/* second bad stripe (for raid6 use) */
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int failb;
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int scrubp;
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/*
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* number of pages needed to represent the full
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* stripe
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*/
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int nr_pages;
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/*
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* size of all the bios in the bio_list. This
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* helps us decide if the rbio maps to a full
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* stripe or not
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*/
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int bio_list_bytes;
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int generic_bio_cnt;
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refcount_t refs;
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atomic_t stripes_pending;
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atomic_t error;
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/*
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* these are two arrays of pointers. We allocate the
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* rbio big enough to hold them both and setup their
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* locations when the rbio is allocated
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*/
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/* pointers to pages that we allocated for
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* reading/writing stripes directly from the disk (including P/Q)
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*/
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struct page **stripe_pages;
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/*
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* pointers to the pages in the bio_list. Stored
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* here for faster lookup
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*/
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struct page **bio_pages;
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/*
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* bitmap to record which horizontal stripe has data
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*/
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unsigned long *dbitmap;
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/* allocated with real_stripes-many pointers for finish_*() calls */
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void **finish_pointers;
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/* allocated with stripe_npages-many bits for finish_*() calls */
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unsigned long *finish_pbitmap;
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};
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static int __raid56_parity_recover(struct btrfs_raid_bio *rbio);
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static noinline void finish_rmw(struct btrfs_raid_bio *rbio);
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static void rmw_work(struct btrfs_work *work);
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static void read_rebuild_work(struct btrfs_work *work);
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static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio);
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static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed);
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static void __free_raid_bio(struct btrfs_raid_bio *rbio);
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static void index_rbio_pages(struct btrfs_raid_bio *rbio);
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static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
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static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
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int need_check);
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static void scrub_parity_work(struct btrfs_work *work);
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static void start_async_work(struct btrfs_raid_bio *rbio, btrfs_func_t work_func)
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{
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btrfs_init_work(&rbio->work, btrfs_rmw_helper, work_func, NULL, NULL);
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btrfs_queue_work(rbio->fs_info->rmw_workers, &rbio->work);
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}
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/*
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* the stripe hash table is used for locking, and to collect
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* bios in hopes of making a full stripe
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*/
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int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
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{
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struct btrfs_stripe_hash_table *table;
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struct btrfs_stripe_hash_table *x;
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struct btrfs_stripe_hash *cur;
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struct btrfs_stripe_hash *h;
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int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
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int i;
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int table_size;
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if (info->stripe_hash_table)
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return 0;
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/*
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* The table is large, starting with order 4 and can go as high as
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* order 7 in case lock debugging is turned on.
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*
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* Try harder to allocate and fallback to vmalloc to lower the chance
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* of a failing mount.
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*/
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table_size = sizeof(*table) + sizeof(*h) * num_entries;
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table = kvzalloc(table_size, GFP_KERNEL);
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if (!table)
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return -ENOMEM;
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spin_lock_init(&table->cache_lock);
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INIT_LIST_HEAD(&table->stripe_cache);
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h = table->table;
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for (i = 0; i < num_entries; i++) {
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cur = h + i;
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INIT_LIST_HEAD(&cur->hash_list);
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spin_lock_init(&cur->lock);
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}
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x = cmpxchg(&info->stripe_hash_table, NULL, table);
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if (x)
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kvfree(x);
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return 0;
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}
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/*
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* caching an rbio means to copy anything from the
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* bio_pages array into the stripe_pages array. We
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* use the page uptodate bit in the stripe cache array
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* to indicate if it has valid data
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*
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* once the caching is done, we set the cache ready
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* bit.
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*/
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static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
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{
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int i;
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char *s;
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char *d;
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int ret;
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ret = alloc_rbio_pages(rbio);
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if (ret)
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return;
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for (i = 0; i < rbio->nr_pages; i++) {
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if (!rbio->bio_pages[i])
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continue;
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s = kmap(rbio->bio_pages[i]);
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d = kmap(rbio->stripe_pages[i]);
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copy_page(d, s);
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kunmap(rbio->bio_pages[i]);
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kunmap(rbio->stripe_pages[i]);
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SetPageUptodate(rbio->stripe_pages[i]);
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}
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set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
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}
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/*
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* we hash on the first logical address of the stripe
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*/
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static int rbio_bucket(struct btrfs_raid_bio *rbio)
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{
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u64 num = rbio->bbio->raid_map[0];
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/*
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* we shift down quite a bit. We're using byte
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* addressing, and most of the lower bits are zeros.
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* This tends to upset hash_64, and it consistently
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* returns just one or two different values.
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*
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* shifting off the lower bits fixes things.
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*/
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return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
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}
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/*
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* stealing an rbio means taking all the uptodate pages from the stripe
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* array in the source rbio and putting them into the destination rbio
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*/
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static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
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{
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int i;
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struct page *s;
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struct page *d;
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if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
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return;
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for (i = 0; i < dest->nr_pages; i++) {
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s = src->stripe_pages[i];
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if (!s || !PageUptodate(s)) {
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continue;
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}
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d = dest->stripe_pages[i];
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if (d)
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__free_page(d);
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dest->stripe_pages[i] = s;
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src->stripe_pages[i] = NULL;
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}
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}
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/*
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* merging means we take the bio_list from the victim and
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* splice it into the destination. The victim should
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* be discarded afterwards.
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*
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* must be called with dest->rbio_list_lock held
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*/
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static void merge_rbio(struct btrfs_raid_bio *dest,
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struct btrfs_raid_bio *victim)
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{
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bio_list_merge(&dest->bio_list, &victim->bio_list);
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dest->bio_list_bytes += victim->bio_list_bytes;
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dest->generic_bio_cnt += victim->generic_bio_cnt;
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bio_list_init(&victim->bio_list);
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}
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/*
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* used to prune items that are in the cache. The caller
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* must hold the hash table lock.
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*/
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static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
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{
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int bucket = rbio_bucket(rbio);
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struct btrfs_stripe_hash_table *table;
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struct btrfs_stripe_hash *h;
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int freeit = 0;
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/*
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* check the bit again under the hash table lock.
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*/
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
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return;
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table = rbio->fs_info->stripe_hash_table;
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h = table->table + bucket;
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/* hold the lock for the bucket because we may be
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* removing it from the hash table
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*/
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spin_lock(&h->lock);
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/*
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* hold the lock for the bio list because we need
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* to make sure the bio list is empty
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*/
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spin_lock(&rbio->bio_list_lock);
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if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
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list_del_init(&rbio->stripe_cache);
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table->cache_size -= 1;
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freeit = 1;
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/* if the bio list isn't empty, this rbio is
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* still involved in an IO. We take it out
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* of the cache list, and drop the ref that
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* was held for the list.
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*
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* If the bio_list was empty, we also remove
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* the rbio from the hash_table, and drop
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* the corresponding ref
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*/
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if (bio_list_empty(&rbio->bio_list)) {
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if (!list_empty(&rbio->hash_list)) {
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list_del_init(&rbio->hash_list);
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refcount_dec(&rbio->refs);
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BUG_ON(!list_empty(&rbio->plug_list));
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}
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}
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}
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spin_unlock(&rbio->bio_list_lock);
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spin_unlock(&h->lock);
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if (freeit)
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__free_raid_bio(rbio);
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}
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/*
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* prune a given rbio from the cache
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*/
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static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
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{
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struct btrfs_stripe_hash_table *table;
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unsigned long flags;
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
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return;
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table = rbio->fs_info->stripe_hash_table;
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spin_lock_irqsave(&table->cache_lock, flags);
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__remove_rbio_from_cache(rbio);
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spin_unlock_irqrestore(&table->cache_lock, flags);
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}
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/*
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* remove everything in the cache
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*/
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static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
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{
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struct btrfs_stripe_hash_table *table;
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unsigned long flags;
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struct btrfs_raid_bio *rbio;
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table = info->stripe_hash_table;
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spin_lock_irqsave(&table->cache_lock, flags);
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while (!list_empty(&table->stripe_cache)) {
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rbio = list_entry(table->stripe_cache.next,
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struct btrfs_raid_bio,
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stripe_cache);
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__remove_rbio_from_cache(rbio);
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}
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spin_unlock_irqrestore(&table->cache_lock, flags);
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}
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/*
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* remove all cached entries and free the hash table
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* used by unmount
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*/
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void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
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{
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if (!info->stripe_hash_table)
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return;
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btrfs_clear_rbio_cache(info);
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kvfree(info->stripe_hash_table);
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info->stripe_hash_table = NULL;
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}
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/*
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* insert an rbio into the stripe cache. It
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* must have already been prepared by calling
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* cache_rbio_pages
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*
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* If this rbio was already cached, it gets
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* moved to the front of the lru.
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*
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* If the size of the rbio cache is too big, we
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* prune an item.
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*/
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static void cache_rbio(struct btrfs_raid_bio *rbio)
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{
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struct btrfs_stripe_hash_table *table;
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unsigned long flags;
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if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
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return;
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table = rbio->fs_info->stripe_hash_table;
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spin_lock_irqsave(&table->cache_lock, flags);
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spin_lock(&rbio->bio_list_lock);
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/* bump our ref if we were not in the list before */
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if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
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refcount_inc(&rbio->refs);
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if (!list_empty(&rbio->stripe_cache)){
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list_move(&rbio->stripe_cache, &table->stripe_cache);
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} else {
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list_add(&rbio->stripe_cache, &table->stripe_cache);
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table->cache_size += 1;
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}
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spin_unlock(&rbio->bio_list_lock);
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if (table->cache_size > RBIO_CACHE_SIZE) {
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struct btrfs_raid_bio *found;
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found = list_entry(table->stripe_cache.prev,
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struct btrfs_raid_bio,
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stripe_cache);
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if (found != rbio)
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__remove_rbio_from_cache(found);
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}
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spin_unlock_irqrestore(&table->cache_lock, flags);
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}
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/*
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* helper function to run the xor_blocks api. It is only
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* able to do MAX_XOR_BLOCKS at a time, so we need to
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* loop through.
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*/
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static void run_xor(void **pages, int src_cnt, ssize_t len)
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{
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int src_off = 0;
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int xor_src_cnt = 0;
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void *dest = pages[src_cnt];
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while(src_cnt > 0) {
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xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
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xor_blocks(xor_src_cnt, len, dest, pages + src_off);
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src_cnt -= xor_src_cnt;
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src_off += xor_src_cnt;
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}
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}
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/*
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* Returns true if the bio list inside this rbio covers an entire stripe (no
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* rmw required).
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*/
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static int rbio_is_full(struct btrfs_raid_bio *rbio)
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{
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unsigned long flags;
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unsigned long size = rbio->bio_list_bytes;
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int ret = 1;
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spin_lock_irqsave(&rbio->bio_list_lock, flags);
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if (size != rbio->nr_data * rbio->stripe_len)
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ret = 0;
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BUG_ON(size > rbio->nr_data * rbio->stripe_len);
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spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
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return ret;
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}
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/*
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* returns 1 if it is safe to merge two rbios together.
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* The merging is safe if the two rbios correspond to
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* the same stripe and if they are both going in the same
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* direction (read vs write), and if neither one is
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* locked for final IO
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*
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* The caller is responsible for locking such that
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* rmw_locked is safe to test
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*/
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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 rbios though, other functions
|
|
* handle that.
|
|
*/
|
|
if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
|
|
test_bit(RBIO_CACHE_BIT, &cur->flags))
|
|
return 0;
|
|
|
|
if (last->bbio->raid_map[0] !=
|
|
cur->bbio->raid_map[0])
|
|
return 0;
|
|
|
|
/* we can't merge with different operations */
|
|
if (last->operation != cur->operation)
|
|
return 0;
|
|
/*
|
|
* We've need read the full stripe from the drive.
|
|
* check and repair 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.
|
|
*/
|
|
if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
|
|
return 0;
|
|
|
|
if (last->operation == BTRFS_RBIO_REBUILD_MISSING)
|
|
return 0;
|
|
|
|
if (last->operation == BTRFS_RBIO_READ_REBUILD) {
|
|
int fa = last->faila;
|
|
int fb = last->failb;
|
|
int cur_fa = cur->faila;
|
|
int cur_fb = cur->failb;
|
|
|
|
if (last->faila >= last->failb) {
|
|
fa = last->failb;
|
|
fb = last->faila;
|
|
}
|
|
|
|
if (cur->faila >= cur->failb) {
|
|
cur_fa = cur->failb;
|
|
cur_fb = cur->faila;
|
|
}
|
|
|
|
if (fa != cur_fa || fb != cur_fb)
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int rbio_stripe_page_index(struct btrfs_raid_bio *rbio, int stripe,
|
|
int index)
|
|
{
|
|
return stripe * rbio->stripe_npages + index;
|
|
}
|
|
|
|
/*
|
|
* 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 index)
|
|
{
|
|
return rbio->stripe_pages[rbio_stripe_page_index(rbio, stripe, index)];
|
|
}
|
|
|
|
/*
|
|
* helper to index into the pstripe
|
|
*/
|
|
static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index)
|
|
{
|
|
return rbio_stripe_page(rbio, rbio->nr_data, 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->real_stripes)
|
|
return NULL;
|
|
return rbio_stripe_page(rbio, rbio->nr_data + 1, 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;
|
|
struct btrfs_raid_bio *freeit = NULL;
|
|
struct btrfs_raid_bio *cache_drop = NULL;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&h->lock, flags);
|
|
list_for_each_entry(cur, &h->hash_list, hash_list) {
|
|
if (cur->bbio->raid_map[0] == rbio->bbio->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);
|
|
refcount_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:
|
|
refcount_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);
|
|
refcount_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);
|
|
refcount_inc(&next->refs);
|
|
spin_unlock(&rbio->bio_list_lock);
|
|
spin_unlock_irqrestore(&h->lock, flags);
|
|
|
|
if (next->operation == BTRFS_RBIO_READ_REBUILD)
|
|
start_async_work(next, read_rebuild_work);
|
|
else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, read_rebuild_work);
|
|
} else if (next->operation == BTRFS_RBIO_WRITE) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, rmw_work);
|
|
} else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, scrub_parity_work);
|
|
}
|
|
|
|
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;
|
|
|
|
if (!refcount_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;
|
|
}
|
|
}
|
|
|
|
btrfs_put_bbio(rbio->bbio);
|
|
kfree(rbio);
|
|
}
|
|
|
|
static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
|
|
{
|
|
struct bio *next;
|
|
|
|
while (cur) {
|
|
next = cur->bi_next;
|
|
cur->bi_next = NULL;
|
|
cur->bi_status = err;
|
|
bio_endio(cur);
|
|
cur = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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, blk_status_t err)
|
|
{
|
|
struct bio *cur = bio_list_get(&rbio->bio_list);
|
|
struct bio *extra;
|
|
|
|
if (rbio->generic_bio_cnt)
|
|
btrfs_bio_counter_sub(rbio->fs_info, rbio->generic_bio_cnt);
|
|
|
|
/*
|
|
* At this moment, rbio->bio_list is empty, however since rbio does not
|
|
* always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the
|
|
* hash list, rbio may be merged with others so that rbio->bio_list
|
|
* becomes non-empty.
|
|
* Once unlock_stripe() is done, rbio->bio_list will not be updated any
|
|
* more and we can call bio_endio() on all queued bios.
|
|
*/
|
|
unlock_stripe(rbio);
|
|
extra = bio_list_get(&rbio->bio_list);
|
|
__free_raid_bio(rbio);
|
|
|
|
rbio_endio_bio_list(cur, err);
|
|
if (extra)
|
|
rbio_endio_bio_list(extra, err);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
blk_status_t err = bio->bi_status;
|
|
int max_errors;
|
|
|
|
if (err)
|
|
fail_bio_stripe(rbio, bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
err = BLK_STS_OK;
|
|
|
|
/* OK, we have read all the stripes we need to. */
|
|
max_errors = (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) ?
|
|
0 : rbio->bbio->max_errors;
|
|
if (atomic_read(&rbio->error) > max_errors)
|
|
err = BLK_STS_IOERR;
|
|
|
|
rbio_orig_end_io(rbio, err);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
return DIV_ROUND_UP(stripe_len, PAGE_SIZE) * nr_stripes;
|
|
}
|
|
|
|
/*
|
|
* 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_fs_info *fs_info,
|
|
struct btrfs_bio *bbio,
|
|
u64 stripe_len)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int nr_data = 0;
|
|
int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
|
|
int num_pages = rbio_nr_pages(stripe_len, real_stripes);
|
|
int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE);
|
|
void *p;
|
|
|
|
rbio = kzalloc(sizeof(*rbio) +
|
|
sizeof(*rbio->stripe_pages) * num_pages +
|
|
sizeof(*rbio->bio_pages) * num_pages +
|
|
sizeof(*rbio->finish_pointers) * real_stripes +
|
|
sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_npages) +
|
|
sizeof(*rbio->finish_pbitmap) *
|
|
BITS_TO_LONGS(stripe_npages),
|
|
GFP_NOFS);
|
|
if (!rbio)
|
|
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->fs_info = fs_info;
|
|
rbio->stripe_len = stripe_len;
|
|
rbio->nr_pages = num_pages;
|
|
rbio->real_stripes = real_stripes;
|
|
rbio->stripe_npages = stripe_npages;
|
|
rbio->faila = -1;
|
|
rbio->failb = -1;
|
|
refcount_set(&rbio->refs, 1);
|
|
atomic_set(&rbio->error, 0);
|
|
atomic_set(&rbio->stripes_pending, 0);
|
|
|
|
/*
|
|
* the stripe_pages, bio_pages, etc arrays point to the extra
|
|
* memory we allocated past the end of the rbio
|
|
*/
|
|
p = rbio + 1;
|
|
#define CONSUME_ALLOC(ptr, count) do { \
|
|
ptr = p; \
|
|
p = (unsigned char *)p + sizeof(*(ptr)) * (count); \
|
|
} while (0)
|
|
CONSUME_ALLOC(rbio->stripe_pages, num_pages);
|
|
CONSUME_ALLOC(rbio->bio_pages, num_pages);
|
|
CONSUME_ALLOC(rbio->finish_pointers, real_stripes);
|
|
CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_npages));
|
|
CONSUME_ALLOC(rbio->finish_pbitmap, BITS_TO_LONGS(stripe_npages));
|
|
#undef CONSUME_ALLOC
|
|
|
|
if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
|
|
nr_data = real_stripes - 1;
|
|
else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
|
|
nr_data = real_stripes - 2;
|
|
else
|
|
BUG();
|
|
|
|
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;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* only allocate pages for p/q stripes */
|
|
static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
|
|
i = rbio_stripe_page_index(rbio, rbio->nr_data, 0);
|
|
|
|
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.
|
|
*/
|
|
static 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_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_iter.bi_sector << 9;
|
|
last_end += last->bi_iter.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 &&
|
|
!last->bi_status &&
|
|
last->bi_disk == stripe->dev->bdev->bd_disk &&
|
|
last->bi_partno == stripe->dev->bdev->bd_partno) {
|
|
ret = bio_add_page(last, page, PAGE_SIZE, 0);
|
|
if (ret == PAGE_SIZE)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* put a new bio on the list */
|
|
bio = btrfs_io_bio_alloc(bio_max_len >> PAGE_SHIFT ?: 1);
|
|
bio->bi_iter.bi_size = 0;
|
|
bio_set_dev(bio, stripe->dev->bdev);
|
|
bio->bi_iter.bi_sector = disk_start >> 9;
|
|
|
|
bio_add_page(bio, page, PAGE_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->real_stripes - 1);
|
|
__raid56_parity_recover(rbio);
|
|
} else {
|
|
finish_rmw(rbio);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
spin_lock_irq(&rbio->bio_list_lock);
|
|
bio_list_for_each(bio, &rbio->bio_list) {
|
|
struct bio_vec bvec;
|
|
struct bvec_iter iter;
|
|
int i = 0;
|
|
|
|
start = (u64)bio->bi_iter.bi_sector << 9;
|
|
stripe_offset = start - rbio->bbio->raid_map[0];
|
|
page_index = stripe_offset >> PAGE_SHIFT;
|
|
|
|
if (bio_flagged(bio, BIO_CLONED))
|
|
bio->bi_iter = btrfs_io_bio(bio)->iter;
|
|
|
|
bio_for_each_segment(bvec, bio, iter) {
|
|
rbio->bio_pages[page_index + i] = bvec.bv_page;
|
|
i++;
|
|
}
|
|
}
|
|
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 = rbio->finish_pointers;
|
|
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 ret;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1) {
|
|
p_stripe = rbio->real_stripes - 1;
|
|
} else if (rbio->real_stripes - rbio->nr_data == 2) {
|
|
p_stripe = rbio->real_stripes - 2;
|
|
q_stripe = rbio->real_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->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 < rbio->stripe_npages; 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(rbio->real_stripes, PAGE_SIZE,
|
|
pointers);
|
|
} else {
|
|
/* raid5 */
|
|
copy_page(pointers[nr_data], pointers[0]);
|
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
|
|
}
|
|
|
|
|
|
for (stripe = 0; stripe < rbio->real_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 < rbio->real_stripes; stripe++) {
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; 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;
|
|
}
|
|
}
|
|
|
|
if (likely(!bbio->num_tgtdevs))
|
|
goto write_data;
|
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
if (!bbio->tgtdev_map[stripe])
|
|
continue;
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; 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,
|
|
rbio->bbio->tgtdev_map[stripe],
|
|
pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
write_data:
|
|
atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list));
|
|
BUG_ON(atomic_read(&rbio->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;
|
|
bio->bi_opf = REQ_OP_WRITE;
|
|
|
|
submit_bio(bio);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* 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_iter.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 &&
|
|
stripe->dev->bdev &&
|
|
bio->bi_disk == stripe->dev->bdev->bd_disk &&
|
|
bio->bi_partno == stripe->dev->bdev->bd_partno) {
|
|
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_iter.bi_sector;
|
|
u64 stripe_start;
|
|
int i;
|
|
|
|
logical <<= 9;
|
|
|
|
for (i = 0; i < rbio->nr_data; i++) {
|
|
stripe_start = rbio->bbio->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->error);
|
|
} else if (rbio->failb == -1) {
|
|
/* second failure on this rbio */
|
|
rbio->failb = failed;
|
|
atomic_inc(&rbio->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)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
|
|
bio_for_each_segment_all(bvec, bio, i)
|
|
SetPageUptodate(bvec->bv_page);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
|
|
if (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
if (atomic_read(&rbio->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, BLK_STS_IOERR);
|
|
}
|
|
|
|
/*
|
|
* 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 bio_list bio_list;
|
|
int ret;
|
|
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->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 < rbio->stripe_npages; 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(&rbio->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;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
/* the actual write will happen once the reads are done */
|
|
return 0;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
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) {
|
|
__free_raid_bio(rbio);
|
|
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)
|
|
start_async_work(rbio, rmw_work);
|
|
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_iter.bi_sector;
|
|
u64 b_sector = rb->bio_list.head->bi_iter.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)) {
|
|
int ret;
|
|
|
|
/* we have a full stripe, send it down */
|
|
ret = full_stripe_write(cur);
|
|
BUG_ON(ret);
|
|
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) {
|
|
btrfs_init_work(&plug->work, btrfs_rmw_helper,
|
|
unplug_work, NULL, NULL);
|
|
btrfs_queue_work(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_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
struct btrfs_plug_cb *plug = NULL;
|
|
struct blk_plug_cb *cb;
|
|
int ret;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio)) {
|
|
btrfs_put_bbio(bbio);
|
|
return PTR_ERR(rbio);
|
|
}
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
rbio->bio_list_bytes = bio->bi_iter.bi_size;
|
|
rbio->operation = BTRFS_RBIO_WRITE;
|
|
|
|
btrfs_bio_counter_inc_noblocked(fs_info);
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
/*
|
|
* don't plug on full rbios, just get them out the door
|
|
* as quickly as we can
|
|
*/
|
|
if (rbio_is_full(rbio)) {
|
|
ret = full_stripe_write(rbio);
|
|
if (ret)
|
|
btrfs_bio_counter_dec(fs_info);
|
|
return ret;
|
|
}
|
|
|
|
cb = blk_check_plugged(btrfs_raid_unplug, fs_info, sizeof(*plug));
|
|
if (cb) {
|
|
plug = container_of(cb, struct btrfs_plug_cb, cb);
|
|
if (!plug->info) {
|
|
plug->info = fs_info;
|
|
INIT_LIST_HEAD(&plug->rbio_list);
|
|
}
|
|
list_add_tail(&rbio->plug_list, &plug->rbio_list);
|
|
ret = 0;
|
|
} else {
|
|
ret = __raid56_parity_write(rbio);
|
|
if (ret)
|
|
btrfs_bio_counter_dec(fs_info);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
struct page *page;
|
|
blk_status_t err;
|
|
int i;
|
|
|
|
pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
|
|
if (!pointers) {
|
|
err = BLK_STS_RESOURCE;
|
|
goto cleanup_io;
|
|
}
|
|
|
|
faila = rbio->faila;
|
|
failb = rbio->failb;
|
|
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
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 < rbio->stripe_npages; pagenr++) {
|
|
/*
|
|
* Now we just use bitmap to mark the horizontal stripes in
|
|
* which we have data when doing parity scrub.
|
|
*/
|
|
if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
|
|
!test_bit(pagenr, rbio->dbitmap))
|
|
continue;
|
|
|
|
/* setup our array of pointers with pages
|
|
* from each stripe
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
/*
|
|
* if we're rebuilding a read, we have to use
|
|
* pages from the bio list
|
|
*/
|
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
|
|
(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->bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) {
|
|
/*
|
|
* 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 = BLK_STS_IOERR;
|
|
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->bbio->raid_map[failb] == RAID6_Q_STRIPE) {
|
|
if (rbio->bbio->raid_map[faila] ==
|
|
RAID5_P_STRIPE) {
|
|
err = BLK_STS_IOERR;
|
|
goto cleanup;
|
|
}
|
|
/*
|
|
* otherwise we have one bad data stripe and
|
|
* a good P stripe. raid5!
|
|
*/
|
|
goto pstripe;
|
|
}
|
|
|
|
if (rbio->bbio->raid_map[failb] == RAID5_P_STRIPE) {
|
|
raid6_datap_recov(rbio->real_stripes,
|
|
PAGE_SIZE, faila, pointers);
|
|
} else {
|
|
raid6_2data_recov(rbio->real_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 */
|
|
copy_page(pointers[faila], pointers[rbio->nr_data]);
|
|
|
|
/* 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_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->operation == BTRFS_RBIO_WRITE) {
|
|
for (i = 0; i < rbio->stripe_npages; 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->real_stripes; stripe++) {
|
|
/*
|
|
* if we're rebuilding a read, we have to use
|
|
* pages from the bio list
|
|
*/
|
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
|
|
(stripe == faila || stripe == failb)) {
|
|
page = page_in_rbio(rbio, stripe, pagenr, 0);
|
|
} else {
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
}
|
|
kunmap(page);
|
|
}
|
|
}
|
|
|
|
err = BLK_STS_OK;
|
|
cleanup:
|
|
kfree(pointers);
|
|
|
|
cleanup_io:
|
|
/*
|
|
* Similar to READ_REBUILD, REBUILD_MISSING at this point also has a
|
|
* valid rbio which is consistent with ondisk content, thus such a
|
|
* valid rbio can be cached to avoid further disk reads.
|
|
*/
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
/*
|
|
* - In case of two failures, where rbio->failb != -1:
|
|
*
|
|
* Do not cache this rbio since the above read reconstruction
|
|
* (raid6_datap_recov() or raid6_2data_recov()) may have
|
|
* changed some content of stripes which are not identical to
|
|
* on-disk content any more, otherwise, a later write/recover
|
|
* may steal stripe_pages from this rbio and end up with
|
|
* corruptions or rebuild failures.
|
|
*
|
|
* - In case of single failure, where rbio->failb == -1:
|
|
*
|
|
* Cache this rbio iff the above read reconstruction is
|
|
* excuted without problems.
|
|
*/
|
|
if (err == BLK_STS_OK && rbio->failb < 0)
|
|
cache_rbio_pages(rbio);
|
|
else
|
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
|
|
|
|
rbio_orig_end_io(rbio, err);
|
|
} else if (err == BLK_STS_OK) {
|
|
rbio->faila = -1;
|
|
rbio->failb = -1;
|
|
|
|
if (rbio->operation == BTRFS_RBIO_WRITE)
|
|
finish_rmw(rbio);
|
|
else if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB)
|
|
finish_parity_scrub(rbio, 0);
|
|
else
|
|
BUG();
|
|
} else {
|
|
rbio_orig_end_io(rbio, err);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is called only for stripes we've read from disk to
|
|
* reconstruct the parity.
|
|
*/
|
|
static void raid_recover_end_io(struct bio *bio)
|
|
{
|
|
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 (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
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 bio_list bio_list;
|
|
int ret;
|
|
int pagenr;
|
|
int stripe;
|
|
struct bio *bio;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
ret = alloc_rbio_pages(rbio);
|
|
if (ret)
|
|
goto cleanup;
|
|
|
|
atomic_set(&rbio->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 < rbio->real_stripes; stripe++) {
|
|
if (rbio->faila == stripe || rbio->failb == stripe) {
|
|
atomic_inc(&rbio->error);
|
|
continue;
|
|
}
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; 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->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(&rbio->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;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
out:
|
|
return 0;
|
|
|
|
cleanup:
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING)
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
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_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len,
|
|
int mirror_num, int generic_io)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int ret;
|
|
|
|
if (generic_io) {
|
|
ASSERT(bbio->mirror_num == mirror_num);
|
|
btrfs_io_bio(bio)->mirror_num = mirror_num;
|
|
}
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio)) {
|
|
if (generic_io)
|
|
btrfs_put_bbio(bbio);
|
|
return PTR_ERR(rbio);
|
|
}
|
|
|
|
rbio->operation = BTRFS_RBIO_READ_REBUILD;
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
rbio->bio_list_bytes = bio->bi_iter.bi_size;
|
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio);
|
|
if (rbio->faila == -1) {
|
|
btrfs_warn(fs_info,
|
|
"%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)",
|
|
__func__, (u64)bio->bi_iter.bi_sector << 9,
|
|
(u64)bio->bi_iter.bi_size, bbio->map_type);
|
|
if (generic_io)
|
|
btrfs_put_bbio(bbio);
|
|
kfree(rbio);
|
|
return -EIO;
|
|
}
|
|
|
|
if (generic_io) {
|
|
btrfs_bio_counter_inc_noblocked(fs_info);
|
|
rbio->generic_bio_cnt = 1;
|
|
} else {
|
|
btrfs_get_bbio(bbio);
|
|
}
|
|
|
|
/*
|
|
* Loop retry:
|
|
* for 'mirror == 2', reconstruct from all other stripes.
|
|
* for 'mirror_num > 2', select a stripe to fail on every retry.
|
|
*/
|
|
if (mirror_num > 2) {
|
|
/*
|
|
* 'mirror == 3' is to fail the p stripe and
|
|
* reconstruct from the q stripe. 'mirror > 3' is to
|
|
* fail a data stripe and reconstruct from p+q stripe.
|
|
*/
|
|
rbio->failb = rbio->real_stripes - (mirror_num - 1);
|
|
ASSERT(rbio->failb > 0);
|
|
if (rbio->failb <= rbio->faila)
|
|
rbio->failb--;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* The following code is used to scrub/replace the parity stripe
|
|
*
|
|
* Caller must have already increased bio_counter for getting @bbio.
|
|
*
|
|
* Note: We need make sure all the pages that add into the scrub/replace
|
|
* raid bio are correct and not be changed during the scrub/replace. That
|
|
* is those pages just hold metadata or file data with checksum.
|
|
*/
|
|
|
|
struct btrfs_raid_bio *
|
|
raid56_parity_alloc_scrub_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len,
|
|
struct btrfs_device *scrub_dev,
|
|
unsigned long *dbitmap, int stripe_nsectors)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int i;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio))
|
|
return NULL;
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
/*
|
|
* This is a special bio which is used to hold the completion handler
|
|
* and make the scrub rbio is similar to the other types
|
|
*/
|
|
ASSERT(!bio->bi_iter.bi_size);
|
|
rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
|
|
|
|
/*
|
|
* After mapping bbio with BTRFS_MAP_WRITE, parities have been sorted
|
|
* to the end position, so this search can start from the first parity
|
|
* stripe.
|
|
*/
|
|
for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
|
|
if (bbio->stripes[i].dev == scrub_dev) {
|
|
rbio->scrubp = i;
|
|
break;
|
|
}
|
|
}
|
|
ASSERT(i < rbio->real_stripes);
|
|
|
|
/* Now we just support the sectorsize equals to page size */
|
|
ASSERT(fs_info->sectorsize == PAGE_SIZE);
|
|
ASSERT(rbio->stripe_npages == stripe_nsectors);
|
|
bitmap_copy(rbio->dbitmap, dbitmap, stripe_nsectors);
|
|
|
|
/*
|
|
* We have already increased bio_counter when getting bbio, record it
|
|
* so we can free it at rbio_orig_end_io().
|
|
*/
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
return rbio;
|
|
}
|
|
|
|
/* Used for both parity scrub and missing. */
|
|
void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
|
|
u64 logical)
|
|
{
|
|
int stripe_offset;
|
|
int index;
|
|
|
|
ASSERT(logical >= rbio->bbio->raid_map[0]);
|
|
ASSERT(logical + PAGE_SIZE <= rbio->bbio->raid_map[0] +
|
|
rbio->stripe_len * rbio->nr_data);
|
|
stripe_offset = (int)(logical - rbio->bbio->raid_map[0]);
|
|
index = stripe_offset >> PAGE_SHIFT;
|
|
rbio->bio_pages[index] = page;
|
|
}
|
|
|
|
/*
|
|
* We just scrub the parity that we have correct data on the same horizontal,
|
|
* so we needn't allocate all pages for all the stripes.
|
|
*/
|
|
static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
int bit;
|
|
int index;
|
|
struct page *page;
|
|
|
|
for_each_set_bit(bit, rbio->dbitmap, rbio->stripe_npages) {
|
|
for (i = 0; i < rbio->real_stripes; i++) {
|
|
index = i * rbio->stripe_npages + bit;
|
|
if (rbio->stripe_pages[index])
|
|
continue;
|
|
|
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
rbio->stripe_pages[index] = page;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
|
|
int need_check)
|
|
{
|
|
struct btrfs_bio *bbio = rbio->bbio;
|
|
void **pointers = rbio->finish_pointers;
|
|
unsigned long *pbitmap = rbio->finish_pbitmap;
|
|
int nr_data = rbio->nr_data;
|
|
int stripe;
|
|
int pagenr;
|
|
int p_stripe = -1;
|
|
int q_stripe = -1;
|
|
struct page *p_page = NULL;
|
|
struct page *q_page = NULL;
|
|
struct bio_list bio_list;
|
|
struct bio *bio;
|
|
int is_replace = 0;
|
|
int ret;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1) {
|
|
p_stripe = rbio->real_stripes - 1;
|
|
} else if (rbio->real_stripes - rbio->nr_data == 2) {
|
|
p_stripe = rbio->real_stripes - 2;
|
|
q_stripe = rbio->real_stripes - 1;
|
|
} else {
|
|
BUG();
|
|
}
|
|
|
|
if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) {
|
|
is_replace = 1;
|
|
bitmap_copy(pbitmap, rbio->dbitmap, rbio->stripe_npages);
|
|
}
|
|
|
|
/*
|
|
* Because the higher layers(scrubber) are unlikely to
|
|
* use this area of the disk again soon, so don't cache
|
|
* it.
|
|
*/
|
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
|
|
|
|
if (!need_check)
|
|
goto writeback;
|
|
|
|
p_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!p_page)
|
|
goto cleanup;
|
|
SetPageUptodate(p_page);
|
|
|
|
if (q_stripe != -1) {
|
|
q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!q_page) {
|
|
__free_page(p_page);
|
|
goto cleanup;
|
|
}
|
|
SetPageUptodate(q_page);
|
|
}
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
struct page *p;
|
|
void *parity;
|
|
/* 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 */
|
|
pointers[stripe++] = kmap(p_page);
|
|
|
|
if (q_stripe != -1) {
|
|
|
|
/*
|
|
* raid6, add the qstripe and call the
|
|
* library function to fill in our p/q
|
|
*/
|
|
pointers[stripe++] = kmap(q_page);
|
|
|
|
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
|
|
pointers);
|
|
} else {
|
|
/* raid5 */
|
|
copy_page(pointers[nr_data], pointers[0]);
|
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
|
|
}
|
|
|
|
/* Check scrubbing parity and repair it */
|
|
p = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
parity = kmap(p);
|
|
if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))
|
|
copy_page(parity, pointers[rbio->scrubp]);
|
|
else
|
|
/* Parity is right, needn't writeback */
|
|
bitmap_clear(rbio->dbitmap, pagenr, 1);
|
|
kunmap(p);
|
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++)
|
|
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
|
|
}
|
|
|
|
__free_page(p_page);
|
|
if (q_page)
|
|
__free_page(q_page);
|
|
|
|
writeback:
|
|
/*
|
|
* 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_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
struct page *page;
|
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
ret = rbio_add_io_page(rbio, &bio_list,
|
|
page, rbio->scrubp, pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
|
|
if (!is_replace)
|
|
goto submit_write;
|
|
|
|
for_each_set_bit(pagenr, pbitmap, rbio->stripe_npages) {
|
|
struct page *page;
|
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
ret = rbio_add_io_page(rbio, &bio_list, page,
|
|
bbio->tgtdev_map[rbio->scrubp],
|
|
pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
|
|
submit_write:
|
|
nr_data = bio_list_size(&bio_list);
|
|
if (!nr_data) {
|
|
/* Every parity is right */
|
|
rbio_orig_end_io(rbio, BLK_STS_OK);
|
|
return;
|
|
}
|
|
|
|
atomic_set(&rbio->stripes_pending, nr_data);
|
|
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid_write_end_io;
|
|
bio->bi_opf = REQ_OP_WRITE;
|
|
|
|
submit_bio(bio);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
}
|
|
|
|
static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
|
|
{
|
|
if (stripe >= 0 && stripe < rbio->nr_data)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* While we're doing the parity check and repair, 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
|
|
* parity scrub will be finished after we've reconstructed the failed
|
|
* stripes
|
|
*/
|
|
static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
|
|
goto cleanup;
|
|
|
|
if (rbio->faila >= 0 || rbio->failb >= 0) {
|
|
int dfail = 0, failp = -1;
|
|
|
|
if (is_data_stripe(rbio, rbio->faila))
|
|
dfail++;
|
|
else if (is_parity_stripe(rbio->faila))
|
|
failp = rbio->faila;
|
|
|
|
if (is_data_stripe(rbio, rbio->failb))
|
|
dfail++;
|
|
else if (is_parity_stripe(rbio->failb))
|
|
failp = rbio->failb;
|
|
|
|
/*
|
|
* Because we can not use a scrubbing parity to repair
|
|
* the data, so the capability of the repair is declined.
|
|
* (In the case of RAID5, we can not repair anything)
|
|
*/
|
|
if (dfail > rbio->bbio->max_errors - 1)
|
|
goto cleanup;
|
|
|
|
/*
|
|
* If all data is good, only parity is correctly, just
|
|
* repair the parity.
|
|
*/
|
|
if (dfail == 0) {
|
|
finish_parity_scrub(rbio, 0);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Here means we got one corrupted data stripe and one
|
|
* corrupted parity on RAID6, if the corrupted parity
|
|
* is scrubbing parity, luckily, use the other one to repair
|
|
* the data, or we can not repair the data stripe.
|
|
*/
|
|
if (failp != rbio->scrubp)
|
|
goto cleanup;
|
|
|
|
__raid_recover_end_io(rbio);
|
|
} else {
|
|
finish_parity_scrub(rbio, 1);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
}
|
|
|
|
/*
|
|
* 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 raid56_parity_scrub_end_io(struct bio *bio)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
|
|
if (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
/*
|
|
* 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_parity_scrub(rbio);
|
|
}
|
|
|
|
static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bios_to_read = 0;
|
|
struct bio_list bio_list;
|
|
int ret;
|
|
int pagenr;
|
|
int stripe;
|
|
struct bio *bio;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
ret = alloc_rbio_essential_pages(rbio);
|
|
if (ret)
|
|
goto cleanup;
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
/*
|
|
* build a list of bios to read all the missing parts of this
|
|
* stripe
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
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(&rbio->stripes_pending, bios_to_read);
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid56_parity_scrub_end_io;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
/* the actual write will happen once the reads are done */
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
return;
|
|
|
|
finish:
|
|
validate_rbio_for_parity_scrub(rbio);
|
|
}
|
|
|
|
static void scrub_parity_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work);
|
|
raid56_parity_scrub_stripe(rbio);
|
|
}
|
|
|
|
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (!lock_stripe_add(rbio))
|
|
start_async_work(rbio, scrub_parity_work);
|
|
}
|
|
|
|
/* The following code is used for dev replace of a missing RAID 5/6 device. */
|
|
|
|
struct btrfs_raid_bio *
|
|
raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 length)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, length);
|
|
if (IS_ERR(rbio))
|
|
return NULL;
|
|
|
|
rbio->operation = BTRFS_RBIO_REBUILD_MISSING;
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
/*
|
|
* This is a special bio which is used to hold the completion handler
|
|
* and make the scrub rbio is similar to the other types
|
|
*/
|
|
ASSERT(!bio->bi_iter.bi_size);
|
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio);
|
|
if (rbio->faila == -1) {
|
|
BUG();
|
|
kfree(rbio);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* When we get bbio, we have already increased bio_counter, record it
|
|
* so we can free it at rbio_orig_end_io()
|
|
*/
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
return rbio;
|
|
}
|
|
|
|
void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (!lock_stripe_add(rbio))
|
|
start_async_work(rbio, read_rebuild_work);
|
|
}
|