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b7044d41b5
When attempting to add a spare to a RAID10 array, also consider adding it as a replacement for a want_replacement device. Signed-off-by: NeilBrown <neilb@suse.de>
3463 lines
93 KiB
C
3463 lines
93 KiB
C
/*
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* raid10.c : Multiple Devices driver for Linux
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*
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* Copyright (C) 2000-2004 Neil Brown
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*
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* RAID-10 support for md.
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*
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* Base on code in raid1.c. See raid1.c for further copyright information.
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* You should have received a copy of the GNU General Public License
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* (for example /usr/src/linux/COPYING); if not, write to the Free
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* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/ratelimit.h>
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#include "md.h"
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#include "raid10.h"
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#include "raid0.h"
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#include "bitmap.h"
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/*
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* RAID10 provides a combination of RAID0 and RAID1 functionality.
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* The layout of data is defined by
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* chunk_size
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* raid_disks
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* near_copies (stored in low byte of layout)
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* far_copies (stored in second byte of layout)
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* far_offset (stored in bit 16 of layout )
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*
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* The data to be stored is divided into chunks using chunksize.
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* Each device is divided into far_copies sections.
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* In each section, chunks are laid out in a style similar to raid0, but
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* near_copies copies of each chunk is stored (each on a different drive).
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* The starting device for each section is offset near_copies from the starting
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* device of the previous section.
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* Thus they are (near_copies*far_copies) of each chunk, and each is on a different
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* drive.
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* near_copies and far_copies must be at least one, and their product is at most
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* raid_disks.
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*
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* If far_offset is true, then the far_copies are handled a bit differently.
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* The copies are still in different stripes, but instead of be very far apart
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* on disk, there are adjacent stripes.
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*/
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/*
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* Number of guaranteed r10bios in case of extreme VM load:
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*/
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#define NR_RAID10_BIOS 256
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/* When there are this many requests queue to be written by
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* the raid10 thread, we become 'congested' to provide back-pressure
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* for writeback.
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*/
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static int max_queued_requests = 1024;
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static void allow_barrier(struct r10conf *conf);
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static void lower_barrier(struct r10conf *conf);
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static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
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{
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struct r10conf *conf = data;
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int size = offsetof(struct r10bio, devs[conf->copies]);
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/* allocate a r10bio with room for raid_disks entries in the
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* bios array */
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return kzalloc(size, gfp_flags);
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}
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static void r10bio_pool_free(void *r10_bio, void *data)
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{
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kfree(r10_bio);
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}
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/* Maximum size of each resync request */
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#define RESYNC_BLOCK_SIZE (64*1024)
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#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
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/* amount of memory to reserve for resync requests */
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#define RESYNC_WINDOW (1024*1024)
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/* maximum number of concurrent requests, memory permitting */
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#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
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/*
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* When performing a resync, we need to read and compare, so
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* we need as many pages are there are copies.
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* When performing a recovery, we need 2 bios, one for read,
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* one for write (we recover only one drive per r10buf)
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*
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*/
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static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
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{
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struct r10conf *conf = data;
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struct page *page;
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struct r10bio *r10_bio;
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struct bio *bio;
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int i, j;
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int nalloc;
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r10_bio = r10bio_pool_alloc(gfp_flags, conf);
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if (!r10_bio)
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return NULL;
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if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
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nalloc = conf->copies; /* resync */
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else
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nalloc = 2; /* recovery */
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/*
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* Allocate bios.
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*/
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for (j = nalloc ; j-- ; ) {
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bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
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if (!bio)
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goto out_free_bio;
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r10_bio->devs[j].bio = bio;
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if (!conf->have_replacement)
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continue;
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bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
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if (!bio)
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goto out_free_bio;
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r10_bio->devs[j].repl_bio = bio;
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}
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/*
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* Allocate RESYNC_PAGES data pages and attach them
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* where needed.
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*/
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for (j = 0 ; j < nalloc; j++) {
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struct bio *rbio = r10_bio->devs[j].repl_bio;
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bio = r10_bio->devs[j].bio;
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for (i = 0; i < RESYNC_PAGES; i++) {
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if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
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&conf->mddev->recovery)) {
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/* we can share bv_page's during recovery */
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struct bio *rbio = r10_bio->devs[0].bio;
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page = rbio->bi_io_vec[i].bv_page;
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get_page(page);
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} else
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page = alloc_page(gfp_flags);
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if (unlikely(!page))
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goto out_free_pages;
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bio->bi_io_vec[i].bv_page = page;
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if (rbio)
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rbio->bi_io_vec[i].bv_page = page;
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}
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}
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return r10_bio;
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out_free_pages:
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for ( ; i > 0 ; i--)
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safe_put_page(bio->bi_io_vec[i-1].bv_page);
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while (j--)
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for (i = 0; i < RESYNC_PAGES ; i++)
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safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
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j = -1;
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out_free_bio:
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while (++j < nalloc) {
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bio_put(r10_bio->devs[j].bio);
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if (r10_bio->devs[j].repl_bio)
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bio_put(r10_bio->devs[j].repl_bio);
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}
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r10bio_pool_free(r10_bio, conf);
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return NULL;
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}
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static void r10buf_pool_free(void *__r10_bio, void *data)
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{
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int i;
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struct r10conf *conf = data;
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struct r10bio *r10bio = __r10_bio;
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int j;
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for (j=0; j < conf->copies; j++) {
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struct bio *bio = r10bio->devs[j].bio;
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if (bio) {
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for (i = 0; i < RESYNC_PAGES; i++) {
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safe_put_page(bio->bi_io_vec[i].bv_page);
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bio->bi_io_vec[i].bv_page = NULL;
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}
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bio_put(bio);
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}
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bio = r10bio->devs[j].repl_bio;
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if (bio)
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bio_put(bio);
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}
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r10bio_pool_free(r10bio, conf);
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}
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static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
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{
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int i;
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for (i = 0; i < conf->copies; i++) {
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struct bio **bio = & r10_bio->devs[i].bio;
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if (!BIO_SPECIAL(*bio))
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bio_put(*bio);
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*bio = NULL;
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bio = &r10_bio->devs[i].repl_bio;
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if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
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bio_put(*bio);
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*bio = NULL;
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}
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}
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static void free_r10bio(struct r10bio *r10_bio)
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{
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struct r10conf *conf = r10_bio->mddev->private;
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put_all_bios(conf, r10_bio);
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mempool_free(r10_bio, conf->r10bio_pool);
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}
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static void put_buf(struct r10bio *r10_bio)
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{
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struct r10conf *conf = r10_bio->mddev->private;
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mempool_free(r10_bio, conf->r10buf_pool);
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lower_barrier(conf);
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}
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static void reschedule_retry(struct r10bio *r10_bio)
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{
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unsigned long flags;
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struct mddev *mddev = r10_bio->mddev;
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struct r10conf *conf = mddev->private;
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spin_lock_irqsave(&conf->device_lock, flags);
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list_add(&r10_bio->retry_list, &conf->retry_list);
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conf->nr_queued ++;
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spin_unlock_irqrestore(&conf->device_lock, flags);
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/* wake up frozen array... */
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wake_up(&conf->wait_barrier);
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md_wakeup_thread(mddev->thread);
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}
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/*
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* raid_end_bio_io() is called when we have finished servicing a mirrored
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* operation and are ready to return a success/failure code to the buffer
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* cache layer.
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*/
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static void raid_end_bio_io(struct r10bio *r10_bio)
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{
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struct bio *bio = r10_bio->master_bio;
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int done;
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struct r10conf *conf = r10_bio->mddev->private;
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if (bio->bi_phys_segments) {
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unsigned long flags;
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spin_lock_irqsave(&conf->device_lock, flags);
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bio->bi_phys_segments--;
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done = (bio->bi_phys_segments == 0);
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spin_unlock_irqrestore(&conf->device_lock, flags);
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} else
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done = 1;
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if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
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clear_bit(BIO_UPTODATE, &bio->bi_flags);
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if (done) {
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bio_endio(bio, 0);
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/*
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* Wake up any possible resync thread that waits for the device
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* to go idle.
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*/
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allow_barrier(conf);
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}
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free_r10bio(r10_bio);
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}
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/*
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* Update disk head position estimator based on IRQ completion info.
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*/
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static inline void update_head_pos(int slot, struct r10bio *r10_bio)
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{
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struct r10conf *conf = r10_bio->mddev->private;
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conf->mirrors[r10_bio->devs[slot].devnum].head_position =
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r10_bio->devs[slot].addr + (r10_bio->sectors);
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}
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/*
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* Find the disk number which triggered given bio
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*/
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static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
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struct bio *bio, int *slotp, int *replp)
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{
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int slot;
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int repl = 0;
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for (slot = 0; slot < conf->copies; slot++) {
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if (r10_bio->devs[slot].bio == bio)
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break;
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if (r10_bio->devs[slot].repl_bio == bio) {
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repl = 1;
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break;
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}
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}
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BUG_ON(slot == conf->copies);
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update_head_pos(slot, r10_bio);
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if (slotp)
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*slotp = slot;
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if (replp)
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*replp = repl;
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return r10_bio->devs[slot].devnum;
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}
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static void raid10_end_read_request(struct bio *bio, int error)
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{
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int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
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struct r10bio *r10_bio = bio->bi_private;
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int slot, dev;
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struct md_rdev *rdev;
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struct r10conf *conf = r10_bio->mddev->private;
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slot = r10_bio->read_slot;
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dev = r10_bio->devs[slot].devnum;
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rdev = r10_bio->devs[slot].rdev;
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/*
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* this branch is our 'one mirror IO has finished' event handler:
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*/
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update_head_pos(slot, r10_bio);
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if (uptodate) {
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/*
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* Set R10BIO_Uptodate in our master bio, so that
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* we will return a good error code to the higher
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* levels even if IO on some other mirrored buffer fails.
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*
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* The 'master' represents the composite IO operation to
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* user-side. So if something waits for IO, then it will
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* wait for the 'master' bio.
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*/
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set_bit(R10BIO_Uptodate, &r10_bio->state);
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raid_end_bio_io(r10_bio);
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rdev_dec_pending(rdev, conf->mddev);
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} else {
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/*
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* oops, read error - keep the refcount on the rdev
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*/
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char b[BDEVNAME_SIZE];
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printk_ratelimited(KERN_ERR
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"md/raid10:%s: %s: rescheduling sector %llu\n",
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mdname(conf->mddev),
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bdevname(rdev->bdev, b),
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(unsigned long long)r10_bio->sector);
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set_bit(R10BIO_ReadError, &r10_bio->state);
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reschedule_retry(r10_bio);
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}
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}
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static void close_write(struct r10bio *r10_bio)
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{
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/* clear the bitmap if all writes complete successfully */
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bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
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r10_bio->sectors,
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!test_bit(R10BIO_Degraded, &r10_bio->state),
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0);
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md_write_end(r10_bio->mddev);
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}
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static void one_write_done(struct r10bio *r10_bio)
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{
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if (atomic_dec_and_test(&r10_bio->remaining)) {
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if (test_bit(R10BIO_WriteError, &r10_bio->state))
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reschedule_retry(r10_bio);
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else {
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close_write(r10_bio);
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if (test_bit(R10BIO_MadeGood, &r10_bio->state))
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reschedule_retry(r10_bio);
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else
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raid_end_bio_io(r10_bio);
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}
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}
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}
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static void raid10_end_write_request(struct bio *bio, int error)
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{
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int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
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struct r10bio *r10_bio = bio->bi_private;
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int dev;
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int dec_rdev = 1;
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struct r10conf *conf = r10_bio->mddev->private;
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int slot, repl;
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struct md_rdev *rdev = NULL;
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dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
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if (repl)
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rdev = conf->mirrors[dev].replacement;
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if (!rdev) {
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smp_rmb();
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repl = 0;
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rdev = conf->mirrors[dev].rdev;
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}
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/*
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* this branch is our 'one mirror IO has finished' event handler:
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*/
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if (!uptodate) {
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if (repl)
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/* Never record new bad blocks to replacement,
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* just fail it.
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*/
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md_error(rdev->mddev, rdev);
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else {
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set_bit(WriteErrorSeen, &rdev->flags);
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if (!test_and_set_bit(WantReplacement, &rdev->flags))
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set_bit(MD_RECOVERY_NEEDED,
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&rdev->mddev->recovery);
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set_bit(R10BIO_WriteError, &r10_bio->state);
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dec_rdev = 0;
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}
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} else {
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/*
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* Set R10BIO_Uptodate in our master bio, so that
|
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* we will return a good error code for to the higher
|
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* levels even if IO on some other mirrored buffer fails.
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*
|
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* The 'master' represents the composite IO operation to
|
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* user-side. So if something waits for IO, then it will
|
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* wait for the 'master' bio.
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*/
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sector_t first_bad;
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int bad_sectors;
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set_bit(R10BIO_Uptodate, &r10_bio->state);
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/* Maybe we can clear some bad blocks. */
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if (is_badblock(rdev,
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r10_bio->devs[slot].addr,
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r10_bio->sectors,
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&first_bad, &bad_sectors)) {
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bio_put(bio);
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if (repl)
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r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
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else
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r10_bio->devs[slot].bio = IO_MADE_GOOD;
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dec_rdev = 0;
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set_bit(R10BIO_MadeGood, &r10_bio->state);
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}
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}
|
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|
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/*
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*
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* Let's see if all mirrored write operations have finished
|
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* already.
|
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*/
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one_write_done(r10_bio);
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if (dec_rdev)
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rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
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}
|
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|
|
/*
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* RAID10 layout manager
|
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* As well as the chunksize and raid_disks count, there are two
|
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* parameters: near_copies and far_copies.
|
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* near_copies * far_copies must be <= raid_disks.
|
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* Normally one of these will be 1.
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* If both are 1, we get raid0.
|
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* If near_copies == raid_disks, we get raid1.
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*
|
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* Chunks are laid out in raid0 style with near_copies copies of the
|
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* first chunk, followed by near_copies copies of the next chunk and
|
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* so on.
|
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* If far_copies > 1, then after 1/far_copies of the array has been assigned
|
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* as described above, we start again with a device offset of near_copies.
|
|
* So we effectively have another copy of the whole array further down all
|
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* the drives, but with blocks on different drives.
|
|
* With this layout, and block is never stored twice on the one device.
|
|
*
|
|
* raid10_find_phys finds the sector offset of a given virtual sector
|
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* on each device that it is on.
|
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*
|
|
* raid10_find_virt does the reverse mapping, from a device and a
|
|
* sector offset to a virtual address
|
|
*/
|
|
|
|
static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
|
|
{
|
|
int n,f;
|
|
sector_t sector;
|
|
sector_t chunk;
|
|
sector_t stripe;
|
|
int dev;
|
|
|
|
int slot = 0;
|
|
|
|
/* now calculate first sector/dev */
|
|
chunk = r10bio->sector >> conf->chunk_shift;
|
|
sector = r10bio->sector & conf->chunk_mask;
|
|
|
|
chunk *= conf->near_copies;
|
|
stripe = chunk;
|
|
dev = sector_div(stripe, conf->raid_disks);
|
|
if (conf->far_offset)
|
|
stripe *= conf->far_copies;
|
|
|
|
sector += stripe << conf->chunk_shift;
|
|
|
|
/* and calculate all the others */
|
|
for (n=0; n < conf->near_copies; n++) {
|
|
int d = dev;
|
|
sector_t s = sector;
|
|
r10bio->devs[slot].addr = sector;
|
|
r10bio->devs[slot].devnum = d;
|
|
slot++;
|
|
|
|
for (f = 1; f < conf->far_copies; f++) {
|
|
d += conf->near_copies;
|
|
if (d >= conf->raid_disks)
|
|
d -= conf->raid_disks;
|
|
s += conf->stride;
|
|
r10bio->devs[slot].devnum = d;
|
|
r10bio->devs[slot].addr = s;
|
|
slot++;
|
|
}
|
|
dev++;
|
|
if (dev >= conf->raid_disks) {
|
|
dev = 0;
|
|
sector += (conf->chunk_mask + 1);
|
|
}
|
|
}
|
|
BUG_ON(slot != conf->copies);
|
|
}
|
|
|
|
static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
|
|
{
|
|
sector_t offset, chunk, vchunk;
|
|
|
|
offset = sector & conf->chunk_mask;
|
|
if (conf->far_offset) {
|
|
int fc;
|
|
chunk = sector >> conf->chunk_shift;
|
|
fc = sector_div(chunk, conf->far_copies);
|
|
dev -= fc * conf->near_copies;
|
|
if (dev < 0)
|
|
dev += conf->raid_disks;
|
|
} else {
|
|
while (sector >= conf->stride) {
|
|
sector -= conf->stride;
|
|
if (dev < conf->near_copies)
|
|
dev += conf->raid_disks - conf->near_copies;
|
|
else
|
|
dev -= conf->near_copies;
|
|
}
|
|
chunk = sector >> conf->chunk_shift;
|
|
}
|
|
vchunk = chunk * conf->raid_disks + dev;
|
|
sector_div(vchunk, conf->near_copies);
|
|
return (vchunk << conf->chunk_shift) + offset;
|
|
}
|
|
|
|
/**
|
|
* raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
|
|
* @q: request queue
|
|
* @bvm: properties of new bio
|
|
* @biovec: the request that could be merged to it.
|
|
*
|
|
* Return amount of bytes we can accept at this offset
|
|
* If near_copies == raid_disk, there are no striping issues,
|
|
* but in that case, the function isn't called at all.
|
|
*/
|
|
static int raid10_mergeable_bvec(struct request_queue *q,
|
|
struct bvec_merge_data *bvm,
|
|
struct bio_vec *biovec)
|
|
{
|
|
struct mddev *mddev = q->queuedata;
|
|
sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
|
|
int max;
|
|
unsigned int chunk_sectors = mddev->chunk_sectors;
|
|
unsigned int bio_sectors = bvm->bi_size >> 9;
|
|
|
|
max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
|
|
if (max < 0) max = 0; /* bio_add cannot handle a negative return */
|
|
if (max <= biovec->bv_len && bio_sectors == 0)
|
|
return biovec->bv_len;
|
|
else
|
|
return max;
|
|
}
|
|
|
|
/*
|
|
* This routine returns the disk from which the requested read should
|
|
* be done. There is a per-array 'next expected sequential IO' sector
|
|
* number - if this matches on the next IO then we use the last disk.
|
|
* There is also a per-disk 'last know head position' sector that is
|
|
* maintained from IRQ contexts, both the normal and the resync IO
|
|
* completion handlers update this position correctly. If there is no
|
|
* perfect sequential match then we pick the disk whose head is closest.
|
|
*
|
|
* If there are 2 mirrors in the same 2 devices, performance degrades
|
|
* because position is mirror, not device based.
|
|
*
|
|
* The rdev for the device selected will have nr_pending incremented.
|
|
*/
|
|
|
|
/*
|
|
* FIXME: possibly should rethink readbalancing and do it differently
|
|
* depending on near_copies / far_copies geometry.
|
|
*/
|
|
static struct md_rdev *read_balance(struct r10conf *conf,
|
|
struct r10bio *r10_bio,
|
|
int *max_sectors)
|
|
{
|
|
const sector_t this_sector = r10_bio->sector;
|
|
int disk, slot;
|
|
int sectors = r10_bio->sectors;
|
|
int best_good_sectors;
|
|
sector_t new_distance, best_dist;
|
|
struct md_rdev *rdev, *best_rdev;
|
|
int do_balance;
|
|
int best_slot;
|
|
|
|
raid10_find_phys(conf, r10_bio);
|
|
rcu_read_lock();
|
|
retry:
|
|
sectors = r10_bio->sectors;
|
|
best_slot = -1;
|
|
best_rdev = NULL;
|
|
best_dist = MaxSector;
|
|
best_good_sectors = 0;
|
|
do_balance = 1;
|
|
/*
|
|
* Check if we can balance. We can balance on the whole
|
|
* device if no resync is going on (recovery is ok), or below
|
|
* the resync window. We take the first readable disk when
|
|
* above the resync window.
|
|
*/
|
|
if (conf->mddev->recovery_cp < MaxSector
|
|
&& (this_sector + sectors >= conf->next_resync))
|
|
do_balance = 0;
|
|
|
|
for (slot = 0; slot < conf->copies ; slot++) {
|
|
sector_t first_bad;
|
|
int bad_sectors;
|
|
sector_t dev_sector;
|
|
|
|
if (r10_bio->devs[slot].bio == IO_BLOCKED)
|
|
continue;
|
|
disk = r10_bio->devs[slot].devnum;
|
|
rdev = rcu_dereference(conf->mirrors[disk].replacement);
|
|
if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
|
|
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
|
|
rdev = rcu_dereference(conf->mirrors[disk].rdev);
|
|
if (rdev == NULL)
|
|
continue;
|
|
if (test_bit(Faulty, &rdev->flags))
|
|
continue;
|
|
if (!test_bit(In_sync, &rdev->flags) &&
|
|
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
|
|
continue;
|
|
|
|
dev_sector = r10_bio->devs[slot].addr;
|
|
if (is_badblock(rdev, dev_sector, sectors,
|
|
&first_bad, &bad_sectors)) {
|
|
if (best_dist < MaxSector)
|
|
/* Already have a better slot */
|
|
continue;
|
|
if (first_bad <= dev_sector) {
|
|
/* Cannot read here. If this is the
|
|
* 'primary' device, then we must not read
|
|
* beyond 'bad_sectors' from another device.
|
|
*/
|
|
bad_sectors -= (dev_sector - first_bad);
|
|
if (!do_balance && sectors > bad_sectors)
|
|
sectors = bad_sectors;
|
|
if (best_good_sectors > sectors)
|
|
best_good_sectors = sectors;
|
|
} else {
|
|
sector_t good_sectors =
|
|
first_bad - dev_sector;
|
|
if (good_sectors > best_good_sectors) {
|
|
best_good_sectors = good_sectors;
|
|
best_slot = slot;
|
|
best_rdev = rdev;
|
|
}
|
|
if (!do_balance)
|
|
/* Must read from here */
|
|
break;
|
|
}
|
|
continue;
|
|
} else
|
|
best_good_sectors = sectors;
|
|
|
|
if (!do_balance)
|
|
break;
|
|
|
|
/* This optimisation is debatable, and completely destroys
|
|
* sequential read speed for 'far copies' arrays. So only
|
|
* keep it for 'near' arrays, and review those later.
|
|
*/
|
|
if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending))
|
|
break;
|
|
|
|
/* for far > 1 always use the lowest address */
|
|
if (conf->far_copies > 1)
|
|
new_distance = r10_bio->devs[slot].addr;
|
|
else
|
|
new_distance = abs(r10_bio->devs[slot].addr -
|
|
conf->mirrors[disk].head_position);
|
|
if (new_distance < best_dist) {
|
|
best_dist = new_distance;
|
|
best_slot = slot;
|
|
best_rdev = rdev;
|
|
}
|
|
}
|
|
if (slot >= conf->copies) {
|
|
slot = best_slot;
|
|
rdev = best_rdev;
|
|
}
|
|
|
|
if (slot >= 0) {
|
|
atomic_inc(&rdev->nr_pending);
|
|
if (test_bit(Faulty, &rdev->flags)) {
|
|
/* Cannot risk returning a device that failed
|
|
* before we inc'ed nr_pending
|
|
*/
|
|
rdev_dec_pending(rdev, conf->mddev);
|
|
goto retry;
|
|
}
|
|
r10_bio->read_slot = slot;
|
|
} else
|
|
rdev = NULL;
|
|
rcu_read_unlock();
|
|
*max_sectors = best_good_sectors;
|
|
|
|
return rdev;
|
|
}
|
|
|
|
static int raid10_congested(void *data, int bits)
|
|
{
|
|
struct mddev *mddev = data;
|
|
struct r10conf *conf = mddev->private;
|
|
int i, ret = 0;
|
|
|
|
if ((bits & (1 << BDI_async_congested)) &&
|
|
conf->pending_count >= max_queued_requests)
|
|
return 1;
|
|
|
|
if (mddev_congested(mddev, bits))
|
|
return 1;
|
|
rcu_read_lock();
|
|
for (i = 0; i < conf->raid_disks && ret == 0; i++) {
|
|
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
|
|
if (rdev && !test_bit(Faulty, &rdev->flags)) {
|
|
struct request_queue *q = bdev_get_queue(rdev->bdev);
|
|
|
|
ret |= bdi_congested(&q->backing_dev_info, bits);
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
static void flush_pending_writes(struct r10conf *conf)
|
|
{
|
|
/* Any writes that have been queued but are awaiting
|
|
* bitmap updates get flushed here.
|
|
*/
|
|
spin_lock_irq(&conf->device_lock);
|
|
|
|
if (conf->pending_bio_list.head) {
|
|
struct bio *bio;
|
|
bio = bio_list_get(&conf->pending_bio_list);
|
|
conf->pending_count = 0;
|
|
spin_unlock_irq(&conf->device_lock);
|
|
/* flush any pending bitmap writes to disk
|
|
* before proceeding w/ I/O */
|
|
bitmap_unplug(conf->mddev->bitmap);
|
|
wake_up(&conf->wait_barrier);
|
|
|
|
while (bio) { /* submit pending writes */
|
|
struct bio *next = bio->bi_next;
|
|
bio->bi_next = NULL;
|
|
generic_make_request(bio);
|
|
bio = next;
|
|
}
|
|
} else
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
|
|
/* Barriers....
|
|
* Sometimes we need to suspend IO while we do something else,
|
|
* either some resync/recovery, or reconfigure the array.
|
|
* To do this we raise a 'barrier'.
|
|
* The 'barrier' is a counter that can be raised multiple times
|
|
* to count how many activities are happening which preclude
|
|
* normal IO.
|
|
* We can only raise the barrier if there is no pending IO.
|
|
* i.e. if nr_pending == 0.
|
|
* We choose only to raise the barrier if no-one is waiting for the
|
|
* barrier to go down. This means that as soon as an IO request
|
|
* is ready, no other operations which require a barrier will start
|
|
* until the IO request has had a chance.
|
|
*
|
|
* So: regular IO calls 'wait_barrier'. When that returns there
|
|
* is no backgroup IO happening, It must arrange to call
|
|
* allow_barrier when it has finished its IO.
|
|
* backgroup IO calls must call raise_barrier. Once that returns
|
|
* there is no normal IO happeing. It must arrange to call
|
|
* lower_barrier when the particular background IO completes.
|
|
*/
|
|
|
|
static void raise_barrier(struct r10conf *conf, int force)
|
|
{
|
|
BUG_ON(force && !conf->barrier);
|
|
spin_lock_irq(&conf->resync_lock);
|
|
|
|
/* Wait until no block IO is waiting (unless 'force') */
|
|
wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
|
|
conf->resync_lock, );
|
|
|
|
/* block any new IO from starting */
|
|
conf->barrier++;
|
|
|
|
/* Now wait for all pending IO to complete */
|
|
wait_event_lock_irq(conf->wait_barrier,
|
|
!conf->nr_pending && conf->barrier < RESYNC_DEPTH,
|
|
conf->resync_lock, );
|
|
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
}
|
|
|
|
static void lower_barrier(struct r10conf *conf)
|
|
{
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&conf->resync_lock, flags);
|
|
conf->barrier--;
|
|
spin_unlock_irqrestore(&conf->resync_lock, flags);
|
|
wake_up(&conf->wait_barrier);
|
|
}
|
|
|
|
static void wait_barrier(struct r10conf *conf)
|
|
{
|
|
spin_lock_irq(&conf->resync_lock);
|
|
if (conf->barrier) {
|
|
conf->nr_waiting++;
|
|
wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
|
|
conf->resync_lock,
|
|
);
|
|
conf->nr_waiting--;
|
|
}
|
|
conf->nr_pending++;
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
}
|
|
|
|
static void allow_barrier(struct r10conf *conf)
|
|
{
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&conf->resync_lock, flags);
|
|
conf->nr_pending--;
|
|
spin_unlock_irqrestore(&conf->resync_lock, flags);
|
|
wake_up(&conf->wait_barrier);
|
|
}
|
|
|
|
static void freeze_array(struct r10conf *conf)
|
|
{
|
|
/* stop syncio and normal IO and wait for everything to
|
|
* go quiet.
|
|
* We increment barrier and nr_waiting, and then
|
|
* wait until nr_pending match nr_queued+1
|
|
* This is called in the context of one normal IO request
|
|
* that has failed. Thus any sync request that might be pending
|
|
* will be blocked by nr_pending, and we need to wait for
|
|
* pending IO requests to complete or be queued for re-try.
|
|
* Thus the number queued (nr_queued) plus this request (1)
|
|
* must match the number of pending IOs (nr_pending) before
|
|
* we continue.
|
|
*/
|
|
spin_lock_irq(&conf->resync_lock);
|
|
conf->barrier++;
|
|
conf->nr_waiting++;
|
|
wait_event_lock_irq(conf->wait_barrier,
|
|
conf->nr_pending == conf->nr_queued+1,
|
|
conf->resync_lock,
|
|
flush_pending_writes(conf));
|
|
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
}
|
|
|
|
static void unfreeze_array(struct r10conf *conf)
|
|
{
|
|
/* reverse the effect of the freeze */
|
|
spin_lock_irq(&conf->resync_lock);
|
|
conf->barrier--;
|
|
conf->nr_waiting--;
|
|
wake_up(&conf->wait_barrier);
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
}
|
|
|
|
static void make_request(struct mddev *mddev, struct bio * bio)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
struct r10bio *r10_bio;
|
|
struct bio *read_bio;
|
|
int i;
|
|
int chunk_sects = conf->chunk_mask + 1;
|
|
const int rw = bio_data_dir(bio);
|
|
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
|
|
const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
|
|
unsigned long flags;
|
|
struct md_rdev *blocked_rdev;
|
|
int plugged;
|
|
int sectors_handled;
|
|
int max_sectors;
|
|
|
|
if (unlikely(bio->bi_rw & REQ_FLUSH)) {
|
|
md_flush_request(mddev, bio);
|
|
return;
|
|
}
|
|
|
|
/* If this request crosses a chunk boundary, we need to
|
|
* split it. This will only happen for 1 PAGE (or less) requests.
|
|
*/
|
|
if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
|
|
> chunk_sects &&
|
|
conf->near_copies < conf->raid_disks)) {
|
|
struct bio_pair *bp;
|
|
/* Sanity check -- queue functions should prevent this happening */
|
|
if (bio->bi_vcnt != 1 ||
|
|
bio->bi_idx != 0)
|
|
goto bad_map;
|
|
/* This is a one page bio that upper layers
|
|
* refuse to split for us, so we need to split it.
|
|
*/
|
|
bp = bio_split(bio,
|
|
chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
|
|
|
|
/* Each of these 'make_request' calls will call 'wait_barrier'.
|
|
* If the first succeeds but the second blocks due to the resync
|
|
* thread raising the barrier, we will deadlock because the
|
|
* IO to the underlying device will be queued in generic_make_request
|
|
* and will never complete, so will never reduce nr_pending.
|
|
* So increment nr_waiting here so no new raise_barriers will
|
|
* succeed, and so the second wait_barrier cannot block.
|
|
*/
|
|
spin_lock_irq(&conf->resync_lock);
|
|
conf->nr_waiting++;
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
|
|
make_request(mddev, &bp->bio1);
|
|
make_request(mddev, &bp->bio2);
|
|
|
|
spin_lock_irq(&conf->resync_lock);
|
|
conf->nr_waiting--;
|
|
wake_up(&conf->wait_barrier);
|
|
spin_unlock_irq(&conf->resync_lock);
|
|
|
|
bio_pair_release(bp);
|
|
return;
|
|
bad_map:
|
|
printk("md/raid10:%s: make_request bug: can't convert block across chunks"
|
|
" or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
|
|
(unsigned long long)bio->bi_sector, bio->bi_size >> 10);
|
|
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
|
|
md_write_start(mddev, bio);
|
|
|
|
/*
|
|
* Register the new request and wait if the reconstruction
|
|
* thread has put up a bar for new requests.
|
|
* Continue immediately if no resync is active currently.
|
|
*/
|
|
wait_barrier(conf);
|
|
|
|
r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
|
|
|
|
r10_bio->master_bio = bio;
|
|
r10_bio->sectors = bio->bi_size >> 9;
|
|
|
|
r10_bio->mddev = mddev;
|
|
r10_bio->sector = bio->bi_sector;
|
|
r10_bio->state = 0;
|
|
|
|
/* We might need to issue multiple reads to different
|
|
* devices if there are bad blocks around, so we keep
|
|
* track of the number of reads in bio->bi_phys_segments.
|
|
* If this is 0, there is only one r10_bio and no locking
|
|
* will be needed when the request completes. If it is
|
|
* non-zero, then it is the number of not-completed requests.
|
|
*/
|
|
bio->bi_phys_segments = 0;
|
|
clear_bit(BIO_SEG_VALID, &bio->bi_flags);
|
|
|
|
if (rw == READ) {
|
|
/*
|
|
* read balancing logic:
|
|
*/
|
|
struct md_rdev *rdev;
|
|
int slot;
|
|
|
|
read_again:
|
|
rdev = read_balance(conf, r10_bio, &max_sectors);
|
|
if (!rdev) {
|
|
raid_end_bio_io(r10_bio);
|
|
return;
|
|
}
|
|
slot = r10_bio->read_slot;
|
|
|
|
read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
|
|
md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
|
|
max_sectors);
|
|
|
|
r10_bio->devs[slot].bio = read_bio;
|
|
r10_bio->devs[slot].rdev = rdev;
|
|
|
|
read_bio->bi_sector = r10_bio->devs[slot].addr +
|
|
rdev->data_offset;
|
|
read_bio->bi_bdev = rdev->bdev;
|
|
read_bio->bi_end_io = raid10_end_read_request;
|
|
read_bio->bi_rw = READ | do_sync;
|
|
read_bio->bi_private = r10_bio;
|
|
|
|
if (max_sectors < r10_bio->sectors) {
|
|
/* Could not read all from this device, so we will
|
|
* need another r10_bio.
|
|
*/
|
|
sectors_handled = (r10_bio->sectors + max_sectors
|
|
- bio->bi_sector);
|
|
r10_bio->sectors = max_sectors;
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (bio->bi_phys_segments == 0)
|
|
bio->bi_phys_segments = 2;
|
|
else
|
|
bio->bi_phys_segments++;
|
|
spin_unlock(&conf->device_lock);
|
|
/* Cannot call generic_make_request directly
|
|
* as that will be queued in __generic_make_request
|
|
* and subsequent mempool_alloc might block
|
|
* waiting for it. so hand bio over to raid10d.
|
|
*/
|
|
reschedule_retry(r10_bio);
|
|
|
|
r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
|
|
|
|
r10_bio->master_bio = bio;
|
|
r10_bio->sectors = ((bio->bi_size >> 9)
|
|
- sectors_handled);
|
|
r10_bio->state = 0;
|
|
r10_bio->mddev = mddev;
|
|
r10_bio->sector = bio->bi_sector + sectors_handled;
|
|
goto read_again;
|
|
} else
|
|
generic_make_request(read_bio);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* WRITE:
|
|
*/
|
|
if (conf->pending_count >= max_queued_requests) {
|
|
md_wakeup_thread(mddev->thread);
|
|
wait_event(conf->wait_barrier,
|
|
conf->pending_count < max_queued_requests);
|
|
}
|
|
/* first select target devices under rcu_lock and
|
|
* inc refcount on their rdev. Record them by setting
|
|
* bios[x] to bio
|
|
* If there are known/acknowledged bad blocks on any device
|
|
* on which we have seen a write error, we want to avoid
|
|
* writing to those blocks. This potentially requires several
|
|
* writes to write around the bad blocks. Each set of writes
|
|
* gets its own r10_bio with a set of bios attached. The number
|
|
* of r10_bios is recored in bio->bi_phys_segments just as with
|
|
* the read case.
|
|
*/
|
|
plugged = mddev_check_plugged(mddev);
|
|
|
|
r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
|
|
raid10_find_phys(conf, r10_bio);
|
|
retry_write:
|
|
blocked_rdev = NULL;
|
|
rcu_read_lock();
|
|
max_sectors = r10_bio->sectors;
|
|
|
|
for (i = 0; i < conf->copies; i++) {
|
|
int d = r10_bio->devs[i].devnum;
|
|
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
|
|
struct md_rdev *rrdev = rcu_dereference(
|
|
conf->mirrors[d].replacement);
|
|
if (rdev == rrdev)
|
|
rrdev = NULL;
|
|
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
|
|
atomic_inc(&rdev->nr_pending);
|
|
blocked_rdev = rdev;
|
|
break;
|
|
}
|
|
if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
|
|
atomic_inc(&rrdev->nr_pending);
|
|
blocked_rdev = rrdev;
|
|
break;
|
|
}
|
|
if (rrdev && test_bit(Faulty, &rrdev->flags))
|
|
rrdev = NULL;
|
|
|
|
r10_bio->devs[i].bio = NULL;
|
|
r10_bio->devs[i].repl_bio = NULL;
|
|
if (!rdev || test_bit(Faulty, &rdev->flags)) {
|
|
set_bit(R10BIO_Degraded, &r10_bio->state);
|
|
continue;
|
|
}
|
|
if (test_bit(WriteErrorSeen, &rdev->flags)) {
|
|
sector_t first_bad;
|
|
sector_t dev_sector = r10_bio->devs[i].addr;
|
|
int bad_sectors;
|
|
int is_bad;
|
|
|
|
is_bad = is_badblock(rdev, dev_sector,
|
|
max_sectors,
|
|
&first_bad, &bad_sectors);
|
|
if (is_bad < 0) {
|
|
/* Mustn't write here until the bad block
|
|
* is acknowledged
|
|
*/
|
|
atomic_inc(&rdev->nr_pending);
|
|
set_bit(BlockedBadBlocks, &rdev->flags);
|
|
blocked_rdev = rdev;
|
|
break;
|
|
}
|
|
if (is_bad && first_bad <= dev_sector) {
|
|
/* Cannot write here at all */
|
|
bad_sectors -= (dev_sector - first_bad);
|
|
if (bad_sectors < max_sectors)
|
|
/* Mustn't write more than bad_sectors
|
|
* to other devices yet
|
|
*/
|
|
max_sectors = bad_sectors;
|
|
/* We don't set R10BIO_Degraded as that
|
|
* only applies if the disk is missing,
|
|
* so it might be re-added, and we want to
|
|
* know to recover this chunk.
|
|
* In this case the device is here, and the
|
|
* fact that this chunk is not in-sync is
|
|
* recorded in the bad block log.
|
|
*/
|
|
continue;
|
|
}
|
|
if (is_bad) {
|
|
int good_sectors = first_bad - dev_sector;
|
|
if (good_sectors < max_sectors)
|
|
max_sectors = good_sectors;
|
|
}
|
|
}
|
|
r10_bio->devs[i].bio = bio;
|
|
atomic_inc(&rdev->nr_pending);
|
|
if (rrdev) {
|
|
r10_bio->devs[i].repl_bio = bio;
|
|
atomic_inc(&rrdev->nr_pending);
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (unlikely(blocked_rdev)) {
|
|
/* Have to wait for this device to get unblocked, then retry */
|
|
int j;
|
|
int d;
|
|
|
|
for (j = 0; j < i; j++) {
|
|
if (r10_bio->devs[j].bio) {
|
|
d = r10_bio->devs[j].devnum;
|
|
rdev_dec_pending(conf->mirrors[d].rdev, mddev);
|
|
}
|
|
if (r10_bio->devs[j].repl_bio) {
|
|
struct md_rdev *rdev;
|
|
d = r10_bio->devs[j].devnum;
|
|
rdev = conf->mirrors[d].replacement;
|
|
if (!rdev) {
|
|
/* Race with remove_disk */
|
|
smp_mb();
|
|
rdev = conf->mirrors[d].rdev;
|
|
}
|
|
rdev_dec_pending(rdev, mddev);
|
|
}
|
|
}
|
|
allow_barrier(conf);
|
|
md_wait_for_blocked_rdev(blocked_rdev, mddev);
|
|
wait_barrier(conf);
|
|
goto retry_write;
|
|
}
|
|
|
|
if (max_sectors < r10_bio->sectors) {
|
|
/* We are splitting this into multiple parts, so
|
|
* we need to prepare for allocating another r10_bio.
|
|
*/
|
|
r10_bio->sectors = max_sectors;
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (bio->bi_phys_segments == 0)
|
|
bio->bi_phys_segments = 2;
|
|
else
|
|
bio->bi_phys_segments++;
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
|
|
|
|
atomic_set(&r10_bio->remaining, 1);
|
|
bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
|
|
|
|
for (i = 0; i < conf->copies; i++) {
|
|
struct bio *mbio;
|
|
int d = r10_bio->devs[i].devnum;
|
|
if (!r10_bio->devs[i].bio)
|
|
continue;
|
|
|
|
mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
|
|
md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
|
|
max_sectors);
|
|
r10_bio->devs[i].bio = mbio;
|
|
|
|
mbio->bi_sector = (r10_bio->devs[i].addr+
|
|
conf->mirrors[d].rdev->data_offset);
|
|
mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
|
|
mbio->bi_end_io = raid10_end_write_request;
|
|
mbio->bi_rw = WRITE | do_sync | do_fua;
|
|
mbio->bi_private = r10_bio;
|
|
|
|
atomic_inc(&r10_bio->remaining);
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
bio_list_add(&conf->pending_bio_list, mbio);
|
|
conf->pending_count++;
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
|
|
if (!r10_bio->devs[i].repl_bio)
|
|
continue;
|
|
|
|
mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
|
|
md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
|
|
max_sectors);
|
|
r10_bio->devs[i].repl_bio = mbio;
|
|
|
|
/* We are actively writing to the original device
|
|
* so it cannot disappear, so the replacement cannot
|
|
* become NULL here
|
|
*/
|
|
mbio->bi_sector = (r10_bio->devs[i].addr+
|
|
conf->mirrors[d].replacement->data_offset);
|
|
mbio->bi_bdev = conf->mirrors[d].replacement->bdev;
|
|
mbio->bi_end_io = raid10_end_write_request;
|
|
mbio->bi_rw = WRITE | do_sync | do_fua;
|
|
mbio->bi_private = r10_bio;
|
|
|
|
atomic_inc(&r10_bio->remaining);
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
bio_list_add(&conf->pending_bio_list, mbio);
|
|
conf->pending_count++;
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
}
|
|
|
|
/* Don't remove the bias on 'remaining' (one_write_done) until
|
|
* after checking if we need to go around again.
|
|
*/
|
|
|
|
if (sectors_handled < (bio->bi_size >> 9)) {
|
|
one_write_done(r10_bio);
|
|
/* We need another r10_bio. It has already been counted
|
|
* in bio->bi_phys_segments.
|
|
*/
|
|
r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
|
|
|
|
r10_bio->master_bio = bio;
|
|
r10_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
|
|
|
|
r10_bio->mddev = mddev;
|
|
r10_bio->sector = bio->bi_sector + sectors_handled;
|
|
r10_bio->state = 0;
|
|
goto retry_write;
|
|
}
|
|
one_write_done(r10_bio);
|
|
|
|
/* In case raid10d snuck in to freeze_array */
|
|
wake_up(&conf->wait_barrier);
|
|
|
|
if (do_sync || !mddev->bitmap || !plugged)
|
|
md_wakeup_thread(mddev->thread);
|
|
}
|
|
|
|
static void status(struct seq_file *seq, struct mddev *mddev)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
int i;
|
|
|
|
if (conf->near_copies < conf->raid_disks)
|
|
seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
|
|
if (conf->near_copies > 1)
|
|
seq_printf(seq, " %d near-copies", conf->near_copies);
|
|
if (conf->far_copies > 1) {
|
|
if (conf->far_offset)
|
|
seq_printf(seq, " %d offset-copies", conf->far_copies);
|
|
else
|
|
seq_printf(seq, " %d far-copies", conf->far_copies);
|
|
}
|
|
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
|
|
conf->raid_disks - mddev->degraded);
|
|
for (i = 0; i < conf->raid_disks; i++)
|
|
seq_printf(seq, "%s",
|
|
conf->mirrors[i].rdev &&
|
|
test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
|
|
seq_printf(seq, "]");
|
|
}
|
|
|
|
/* check if there are enough drives for
|
|
* every block to appear on atleast one.
|
|
* Don't consider the device numbered 'ignore'
|
|
* as we might be about to remove it.
|
|
*/
|
|
static int enough(struct r10conf *conf, int ignore)
|
|
{
|
|
int first = 0;
|
|
|
|
do {
|
|
int n = conf->copies;
|
|
int cnt = 0;
|
|
while (n--) {
|
|
if (conf->mirrors[first].rdev &&
|
|
first != ignore)
|
|
cnt++;
|
|
first = (first+1) % conf->raid_disks;
|
|
}
|
|
if (cnt == 0)
|
|
return 0;
|
|
} while (first != 0);
|
|
return 1;
|
|
}
|
|
|
|
static void error(struct mddev *mddev, struct md_rdev *rdev)
|
|
{
|
|
char b[BDEVNAME_SIZE];
|
|
struct r10conf *conf = mddev->private;
|
|
|
|
/*
|
|
* If it is not operational, then we have already marked it as dead
|
|
* else if it is the last working disks, ignore the error, let the
|
|
* next level up know.
|
|
* else mark the drive as failed
|
|
*/
|
|
if (test_bit(In_sync, &rdev->flags)
|
|
&& !enough(conf, rdev->raid_disk))
|
|
/*
|
|
* Don't fail the drive, just return an IO error.
|
|
*/
|
|
return;
|
|
if (test_and_clear_bit(In_sync, &rdev->flags)) {
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
mddev->degraded++;
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
/*
|
|
* if recovery is running, make sure it aborts.
|
|
*/
|
|
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
|
|
}
|
|
set_bit(Blocked, &rdev->flags);
|
|
set_bit(Faulty, &rdev->flags);
|
|
set_bit(MD_CHANGE_DEVS, &mddev->flags);
|
|
printk(KERN_ALERT
|
|
"md/raid10:%s: Disk failure on %s, disabling device.\n"
|
|
"md/raid10:%s: Operation continuing on %d devices.\n",
|
|
mdname(mddev), bdevname(rdev->bdev, b),
|
|
mdname(mddev), conf->raid_disks - mddev->degraded);
|
|
}
|
|
|
|
static void print_conf(struct r10conf *conf)
|
|
{
|
|
int i;
|
|
struct mirror_info *tmp;
|
|
|
|
printk(KERN_DEBUG "RAID10 conf printout:\n");
|
|
if (!conf) {
|
|
printk(KERN_DEBUG "(!conf)\n");
|
|
return;
|
|
}
|
|
printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
|
|
conf->raid_disks);
|
|
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
char b[BDEVNAME_SIZE];
|
|
tmp = conf->mirrors + i;
|
|
if (tmp->rdev)
|
|
printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
|
|
i, !test_bit(In_sync, &tmp->rdev->flags),
|
|
!test_bit(Faulty, &tmp->rdev->flags),
|
|
bdevname(tmp->rdev->bdev,b));
|
|
}
|
|
}
|
|
|
|
static void close_sync(struct r10conf *conf)
|
|
{
|
|
wait_barrier(conf);
|
|
allow_barrier(conf);
|
|
|
|
mempool_destroy(conf->r10buf_pool);
|
|
conf->r10buf_pool = NULL;
|
|
}
|
|
|
|
static int raid10_spare_active(struct mddev *mddev)
|
|
{
|
|
int i;
|
|
struct r10conf *conf = mddev->private;
|
|
struct mirror_info *tmp;
|
|
int count = 0;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Find all non-in_sync disks within the RAID10 configuration
|
|
* and mark them in_sync
|
|
*/
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
tmp = conf->mirrors + i;
|
|
if (tmp->replacement
|
|
&& tmp->replacement->recovery_offset == MaxSector
|
|
&& !test_bit(Faulty, &tmp->replacement->flags)
|
|
&& !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
|
|
/* Replacement has just become active */
|
|
if (!tmp->rdev
|
|
|| !test_and_clear_bit(In_sync, &tmp->rdev->flags))
|
|
count++;
|
|
if (tmp->rdev) {
|
|
/* Replaced device not technically faulty,
|
|
* but we need to be sure it gets removed
|
|
* and never re-added.
|
|
*/
|
|
set_bit(Faulty, &tmp->rdev->flags);
|
|
sysfs_notify_dirent_safe(
|
|
tmp->rdev->sysfs_state);
|
|
}
|
|
sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
|
|
} else if (tmp->rdev
|
|
&& !test_bit(Faulty, &tmp->rdev->flags)
|
|
&& !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
|
|
count++;
|
|
sysfs_notify_dirent(tmp->rdev->sysfs_state);
|
|
}
|
|
}
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
mddev->degraded -= count;
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
|
|
print_conf(conf);
|
|
return count;
|
|
}
|
|
|
|
|
|
static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
int err = -EEXIST;
|
|
int mirror;
|
|
int first = 0;
|
|
int last = conf->raid_disks - 1;
|
|
|
|
if (mddev->recovery_cp < MaxSector)
|
|
/* only hot-add to in-sync arrays, as recovery is
|
|
* very different from resync
|
|
*/
|
|
return -EBUSY;
|
|
if (!enough(conf, -1))
|
|
return -EINVAL;
|
|
|
|
if (rdev->raid_disk >= 0)
|
|
first = last = rdev->raid_disk;
|
|
|
|
if (rdev->saved_raid_disk >= first &&
|
|
conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
|
|
mirror = rdev->saved_raid_disk;
|
|
else
|
|
mirror = first;
|
|
for ( ; mirror <= last ; mirror++) {
|
|
struct mirror_info *p = &conf->mirrors[mirror];
|
|
if (p->recovery_disabled == mddev->recovery_disabled)
|
|
continue;
|
|
if (p->rdev) {
|
|
if (!test_bit(WantReplacement, &p->rdev->flags) ||
|
|
p->replacement != NULL)
|
|
continue;
|
|
clear_bit(In_sync, &rdev->flags);
|
|
set_bit(Replacement, &rdev->flags);
|
|
rdev->raid_disk = mirror;
|
|
err = 0;
|
|
disk_stack_limits(mddev->gendisk, rdev->bdev,
|
|
rdev->data_offset << 9);
|
|
if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
|
|
blk_queue_max_segments(mddev->queue, 1);
|
|
blk_queue_segment_boundary(mddev->queue,
|
|
PAGE_CACHE_SIZE - 1);
|
|
}
|
|
conf->fullsync = 1;
|
|
rcu_assign_pointer(p->replacement, rdev);
|
|
break;
|
|
}
|
|
|
|
disk_stack_limits(mddev->gendisk, rdev->bdev,
|
|
rdev->data_offset << 9);
|
|
/* as we don't honour merge_bvec_fn, we must
|
|
* never risk violating it, so limit
|
|
* ->max_segments to one lying with a single
|
|
* page, as a one page request is never in
|
|
* violation.
|
|
*/
|
|
if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
|
|
blk_queue_max_segments(mddev->queue, 1);
|
|
blk_queue_segment_boundary(mddev->queue,
|
|
PAGE_CACHE_SIZE - 1);
|
|
}
|
|
|
|
p->head_position = 0;
|
|
p->recovery_disabled = mddev->recovery_disabled - 1;
|
|
rdev->raid_disk = mirror;
|
|
err = 0;
|
|
if (rdev->saved_raid_disk != mirror)
|
|
conf->fullsync = 1;
|
|
rcu_assign_pointer(p->rdev, rdev);
|
|
break;
|
|
}
|
|
|
|
md_integrity_add_rdev(rdev, mddev);
|
|
print_conf(conf);
|
|
return err;
|
|
}
|
|
|
|
static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
int err = 0;
|
|
int number = rdev->raid_disk;
|
|
struct md_rdev **rdevp;
|
|
struct mirror_info *p = conf->mirrors + number;
|
|
|
|
print_conf(conf);
|
|
if (rdev == p->rdev)
|
|
rdevp = &p->rdev;
|
|
else if (rdev == p->replacement)
|
|
rdevp = &p->replacement;
|
|
else
|
|
return 0;
|
|
|
|
if (test_bit(In_sync, &rdev->flags) ||
|
|
atomic_read(&rdev->nr_pending)) {
|
|
err = -EBUSY;
|
|
goto abort;
|
|
}
|
|
/* Only remove faulty devices if recovery
|
|
* is not possible.
|
|
*/
|
|
if (!test_bit(Faulty, &rdev->flags) &&
|
|
mddev->recovery_disabled != p->recovery_disabled &&
|
|
(!p->replacement || p->replacement == rdev) &&
|
|
enough(conf, -1)) {
|
|
err = -EBUSY;
|
|
goto abort;
|
|
}
|
|
*rdevp = NULL;
|
|
synchronize_rcu();
|
|
if (atomic_read(&rdev->nr_pending)) {
|
|
/* lost the race, try later */
|
|
err = -EBUSY;
|
|
*rdevp = rdev;
|
|
goto abort;
|
|
} else if (p->replacement) {
|
|
/* We must have just cleared 'rdev' */
|
|
p->rdev = p->replacement;
|
|
clear_bit(Replacement, &p->replacement->flags);
|
|
smp_mb(); /* Make sure other CPUs may see both as identical
|
|
* but will never see neither -- if they are careful.
|
|
*/
|
|
p->replacement = NULL;
|
|
clear_bit(WantReplacement, &rdev->flags);
|
|
} else
|
|
/* We might have just remove the Replacement as faulty
|
|
* Clear the flag just in case
|
|
*/
|
|
clear_bit(WantReplacement, &rdev->flags);
|
|
|
|
err = md_integrity_register(mddev);
|
|
|
|
abort:
|
|
|
|
print_conf(conf);
|
|
return err;
|
|
}
|
|
|
|
|
|
static void end_sync_read(struct bio *bio, int error)
|
|
{
|
|
struct r10bio *r10_bio = bio->bi_private;
|
|
struct r10conf *conf = r10_bio->mddev->private;
|
|
int d;
|
|
|
|
d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
|
|
|
|
if (test_bit(BIO_UPTODATE, &bio->bi_flags))
|
|
set_bit(R10BIO_Uptodate, &r10_bio->state);
|
|
else
|
|
/* The write handler will notice the lack of
|
|
* R10BIO_Uptodate and record any errors etc
|
|
*/
|
|
atomic_add(r10_bio->sectors,
|
|
&conf->mirrors[d].rdev->corrected_errors);
|
|
|
|
/* for reconstruct, we always reschedule after a read.
|
|
* for resync, only after all reads
|
|
*/
|
|
rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
|
|
if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
|
|
atomic_dec_and_test(&r10_bio->remaining)) {
|
|
/* we have read all the blocks,
|
|
* do the comparison in process context in raid10d
|
|
*/
|
|
reschedule_retry(r10_bio);
|
|
}
|
|
}
|
|
|
|
static void end_sync_request(struct r10bio *r10_bio)
|
|
{
|
|
struct mddev *mddev = r10_bio->mddev;
|
|
|
|
while (atomic_dec_and_test(&r10_bio->remaining)) {
|
|
if (r10_bio->master_bio == NULL) {
|
|
/* the primary of several recovery bios */
|
|
sector_t s = r10_bio->sectors;
|
|
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
|
|
test_bit(R10BIO_WriteError, &r10_bio->state))
|
|
reschedule_retry(r10_bio);
|
|
else
|
|
put_buf(r10_bio);
|
|
md_done_sync(mddev, s, 1);
|
|
break;
|
|
} else {
|
|
struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
|
|
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
|
|
test_bit(R10BIO_WriteError, &r10_bio->state))
|
|
reschedule_retry(r10_bio);
|
|
else
|
|
put_buf(r10_bio);
|
|
r10_bio = r10_bio2;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void end_sync_write(struct bio *bio, int error)
|
|
{
|
|
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
struct r10bio *r10_bio = bio->bi_private;
|
|
struct mddev *mddev = r10_bio->mddev;
|
|
struct r10conf *conf = mddev->private;
|
|
int d;
|
|
sector_t first_bad;
|
|
int bad_sectors;
|
|
int slot;
|
|
int repl;
|
|
struct md_rdev *rdev = NULL;
|
|
|
|
d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
|
|
if (repl)
|
|
rdev = conf->mirrors[d].replacement;
|
|
if (!rdev) {
|
|
smp_mb();
|
|
rdev = conf->mirrors[d].rdev;
|
|
}
|
|
|
|
if (!uptodate) {
|
|
if (repl)
|
|
md_error(mddev, rdev);
|
|
else {
|
|
set_bit(WriteErrorSeen, &rdev->flags);
|
|
if (!test_and_set_bit(WantReplacement, &rdev->flags))
|
|
set_bit(MD_RECOVERY_NEEDED,
|
|
&rdev->mddev->recovery);
|
|
set_bit(R10BIO_WriteError, &r10_bio->state);
|
|
}
|
|
} else if (is_badblock(rdev,
|
|
r10_bio->devs[slot].addr,
|
|
r10_bio->sectors,
|
|
&first_bad, &bad_sectors))
|
|
set_bit(R10BIO_MadeGood, &r10_bio->state);
|
|
|
|
rdev_dec_pending(rdev, mddev);
|
|
|
|
end_sync_request(r10_bio);
|
|
}
|
|
|
|
/*
|
|
* Note: sync and recover and handled very differently for raid10
|
|
* This code is for resync.
|
|
* For resync, we read through virtual addresses and read all blocks.
|
|
* If there is any error, we schedule a write. The lowest numbered
|
|
* drive is authoritative.
|
|
* However requests come for physical address, so we need to map.
|
|
* For every physical address there are raid_disks/copies virtual addresses,
|
|
* which is always are least one, but is not necessarly an integer.
|
|
* This means that a physical address can span multiple chunks, so we may
|
|
* have to submit multiple io requests for a single sync request.
|
|
*/
|
|
/*
|
|
* We check if all blocks are in-sync and only write to blocks that
|
|
* aren't in sync
|
|
*/
|
|
static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
int i, first;
|
|
struct bio *tbio, *fbio;
|
|
|
|
atomic_set(&r10_bio->remaining, 1);
|
|
|
|
/* find the first device with a block */
|
|
for (i=0; i<conf->copies; i++)
|
|
if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
|
|
break;
|
|
|
|
if (i == conf->copies)
|
|
goto done;
|
|
|
|
first = i;
|
|
fbio = r10_bio->devs[i].bio;
|
|
|
|
/* now find blocks with errors */
|
|
for (i=0 ; i < conf->copies ; i++) {
|
|
int j, d;
|
|
int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
|
|
|
|
tbio = r10_bio->devs[i].bio;
|
|
|
|
if (tbio->bi_end_io != end_sync_read)
|
|
continue;
|
|
if (i == first)
|
|
continue;
|
|
if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
|
|
/* We know that the bi_io_vec layout is the same for
|
|
* both 'first' and 'i', so we just compare them.
|
|
* All vec entries are PAGE_SIZE;
|
|
*/
|
|
for (j = 0; j < vcnt; j++)
|
|
if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
|
|
page_address(tbio->bi_io_vec[j].bv_page),
|
|
PAGE_SIZE))
|
|
break;
|
|
if (j == vcnt)
|
|
continue;
|
|
mddev->resync_mismatches += r10_bio->sectors;
|
|
if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
|
|
/* Don't fix anything. */
|
|
continue;
|
|
}
|
|
/* Ok, we need to write this bio, either to correct an
|
|
* inconsistency or to correct an unreadable block.
|
|
* First we need to fixup bv_offset, bv_len and
|
|
* bi_vecs, as the read request might have corrupted these
|
|
*/
|
|
tbio->bi_vcnt = vcnt;
|
|
tbio->bi_size = r10_bio->sectors << 9;
|
|
tbio->bi_idx = 0;
|
|
tbio->bi_phys_segments = 0;
|
|
tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
|
|
tbio->bi_flags |= 1 << BIO_UPTODATE;
|
|
tbio->bi_next = NULL;
|
|
tbio->bi_rw = WRITE;
|
|
tbio->bi_private = r10_bio;
|
|
tbio->bi_sector = r10_bio->devs[i].addr;
|
|
|
|
for (j=0; j < vcnt ; j++) {
|
|
tbio->bi_io_vec[j].bv_offset = 0;
|
|
tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
|
|
|
|
memcpy(page_address(tbio->bi_io_vec[j].bv_page),
|
|
page_address(fbio->bi_io_vec[j].bv_page),
|
|
PAGE_SIZE);
|
|
}
|
|
tbio->bi_end_io = end_sync_write;
|
|
|
|
d = r10_bio->devs[i].devnum;
|
|
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
|
|
atomic_inc(&r10_bio->remaining);
|
|
md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
|
|
|
|
tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
|
|
tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
|
|
generic_make_request(tbio);
|
|
}
|
|
|
|
/* Now write out to any replacement devices
|
|
* that are active
|
|
*/
|
|
for (i = 0; i < conf->copies; i++) {
|
|
int j, d;
|
|
int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
|
|
|
|
tbio = r10_bio->devs[i].repl_bio;
|
|
if (!tbio || !tbio->bi_end_io)
|
|
continue;
|
|
if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
|
|
&& r10_bio->devs[i].bio != fbio)
|
|
for (j = 0; j < vcnt; j++)
|
|
memcpy(page_address(tbio->bi_io_vec[j].bv_page),
|
|
page_address(fbio->bi_io_vec[j].bv_page),
|
|
PAGE_SIZE);
|
|
d = r10_bio->devs[i].devnum;
|
|
atomic_inc(&r10_bio->remaining);
|
|
md_sync_acct(conf->mirrors[d].replacement->bdev,
|
|
tbio->bi_size >> 9);
|
|
generic_make_request(tbio);
|
|
}
|
|
|
|
done:
|
|
if (atomic_dec_and_test(&r10_bio->remaining)) {
|
|
md_done_sync(mddev, r10_bio->sectors, 1);
|
|
put_buf(r10_bio);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now for the recovery code.
|
|
* Recovery happens across physical sectors.
|
|
* We recover all non-is_sync drives by finding the virtual address of
|
|
* each, and then choose a working drive that also has that virt address.
|
|
* There is a separate r10_bio for each non-in_sync drive.
|
|
* Only the first two slots are in use. The first for reading,
|
|
* The second for writing.
|
|
*
|
|
*/
|
|
static void fix_recovery_read_error(struct r10bio *r10_bio)
|
|
{
|
|
/* We got a read error during recovery.
|
|
* We repeat the read in smaller page-sized sections.
|
|
* If a read succeeds, write it to the new device or record
|
|
* a bad block if we cannot.
|
|
* If a read fails, record a bad block on both old and
|
|
* new devices.
|
|
*/
|
|
struct mddev *mddev = r10_bio->mddev;
|
|
struct r10conf *conf = mddev->private;
|
|
struct bio *bio = r10_bio->devs[0].bio;
|
|
sector_t sect = 0;
|
|
int sectors = r10_bio->sectors;
|
|
int idx = 0;
|
|
int dr = r10_bio->devs[0].devnum;
|
|
int dw = r10_bio->devs[1].devnum;
|
|
|
|
while (sectors) {
|
|
int s = sectors;
|
|
struct md_rdev *rdev;
|
|
sector_t addr;
|
|
int ok;
|
|
|
|
if (s > (PAGE_SIZE>>9))
|
|
s = PAGE_SIZE >> 9;
|
|
|
|
rdev = conf->mirrors[dr].rdev;
|
|
addr = r10_bio->devs[0].addr + sect,
|
|
ok = sync_page_io(rdev,
|
|
addr,
|
|
s << 9,
|
|
bio->bi_io_vec[idx].bv_page,
|
|
READ, false);
|
|
if (ok) {
|
|
rdev = conf->mirrors[dw].rdev;
|
|
addr = r10_bio->devs[1].addr + sect;
|
|
ok = sync_page_io(rdev,
|
|
addr,
|
|
s << 9,
|
|
bio->bi_io_vec[idx].bv_page,
|
|
WRITE, false);
|
|
if (!ok) {
|
|
set_bit(WriteErrorSeen, &rdev->flags);
|
|
if (!test_and_set_bit(WantReplacement,
|
|
&rdev->flags))
|
|
set_bit(MD_RECOVERY_NEEDED,
|
|
&rdev->mddev->recovery);
|
|
}
|
|
}
|
|
if (!ok) {
|
|
/* We don't worry if we cannot set a bad block -
|
|
* it really is bad so there is no loss in not
|
|
* recording it yet
|
|
*/
|
|
rdev_set_badblocks(rdev, addr, s, 0);
|
|
|
|
if (rdev != conf->mirrors[dw].rdev) {
|
|
/* need bad block on destination too */
|
|
struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
|
|
addr = r10_bio->devs[1].addr + sect;
|
|
ok = rdev_set_badblocks(rdev2, addr, s, 0);
|
|
if (!ok) {
|
|
/* just abort the recovery */
|
|
printk(KERN_NOTICE
|
|
"md/raid10:%s: recovery aborted"
|
|
" due to read error\n",
|
|
mdname(mddev));
|
|
|
|
conf->mirrors[dw].recovery_disabled
|
|
= mddev->recovery_disabled;
|
|
set_bit(MD_RECOVERY_INTR,
|
|
&mddev->recovery);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
sectors -= s;
|
|
sect += s;
|
|
idx++;
|
|
}
|
|
}
|
|
|
|
static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
int d;
|
|
struct bio *wbio, *wbio2;
|
|
|
|
if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
|
|
fix_recovery_read_error(r10_bio);
|
|
end_sync_request(r10_bio);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* share the pages with the first bio
|
|
* and submit the write request
|
|
*/
|
|
d = r10_bio->devs[1].devnum;
|
|
wbio = r10_bio->devs[1].bio;
|
|
wbio2 = r10_bio->devs[1].repl_bio;
|
|
if (wbio->bi_end_io) {
|
|
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
|
|
md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
|
|
generic_make_request(wbio);
|
|
}
|
|
if (wbio2 && wbio2->bi_end_io) {
|
|
atomic_inc(&conf->mirrors[d].replacement->nr_pending);
|
|
md_sync_acct(conf->mirrors[d].replacement->bdev,
|
|
wbio2->bi_size >> 9);
|
|
generic_make_request(wbio2);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Used by fix_read_error() to decay the per rdev read_errors.
|
|
* We halve the read error count for every hour that has elapsed
|
|
* since the last recorded read error.
|
|
*
|
|
*/
|
|
static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
|
|
{
|
|
struct timespec cur_time_mon;
|
|
unsigned long hours_since_last;
|
|
unsigned int read_errors = atomic_read(&rdev->read_errors);
|
|
|
|
ktime_get_ts(&cur_time_mon);
|
|
|
|
if (rdev->last_read_error.tv_sec == 0 &&
|
|
rdev->last_read_error.tv_nsec == 0) {
|
|
/* first time we've seen a read error */
|
|
rdev->last_read_error = cur_time_mon;
|
|
return;
|
|
}
|
|
|
|
hours_since_last = (cur_time_mon.tv_sec -
|
|
rdev->last_read_error.tv_sec) / 3600;
|
|
|
|
rdev->last_read_error = cur_time_mon;
|
|
|
|
/*
|
|
* if hours_since_last is > the number of bits in read_errors
|
|
* just set read errors to 0. We do this to avoid
|
|
* overflowing the shift of read_errors by hours_since_last.
|
|
*/
|
|
if (hours_since_last >= 8 * sizeof(read_errors))
|
|
atomic_set(&rdev->read_errors, 0);
|
|
else
|
|
atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
|
|
}
|
|
|
|
static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
|
|
int sectors, struct page *page, int rw)
|
|
{
|
|
sector_t first_bad;
|
|
int bad_sectors;
|
|
|
|
if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
|
|
&& (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
|
|
return -1;
|
|
if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
|
|
/* success */
|
|
return 1;
|
|
if (rw == WRITE) {
|
|
set_bit(WriteErrorSeen, &rdev->flags);
|
|
if (!test_and_set_bit(WantReplacement, &rdev->flags))
|
|
set_bit(MD_RECOVERY_NEEDED,
|
|
&rdev->mddev->recovery);
|
|
}
|
|
/* need to record an error - either for the block or the device */
|
|
if (!rdev_set_badblocks(rdev, sector, sectors, 0))
|
|
md_error(rdev->mddev, rdev);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is a kernel thread which:
|
|
*
|
|
* 1. Retries failed read operations on working mirrors.
|
|
* 2. Updates the raid superblock when problems encounter.
|
|
* 3. Performs writes following reads for array synchronising.
|
|
*/
|
|
|
|
static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
|
|
{
|
|
int sect = 0; /* Offset from r10_bio->sector */
|
|
int sectors = r10_bio->sectors;
|
|
struct md_rdev*rdev;
|
|
int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
|
|
int d = r10_bio->devs[r10_bio->read_slot].devnum;
|
|
|
|
/* still own a reference to this rdev, so it cannot
|
|
* have been cleared recently.
|
|
*/
|
|
rdev = conf->mirrors[d].rdev;
|
|
|
|
if (test_bit(Faulty, &rdev->flags))
|
|
/* drive has already been failed, just ignore any
|
|
more fix_read_error() attempts */
|
|
return;
|
|
|
|
check_decay_read_errors(mddev, rdev);
|
|
atomic_inc(&rdev->read_errors);
|
|
if (atomic_read(&rdev->read_errors) > max_read_errors) {
|
|
char b[BDEVNAME_SIZE];
|
|
bdevname(rdev->bdev, b);
|
|
|
|
printk(KERN_NOTICE
|
|
"md/raid10:%s: %s: Raid device exceeded "
|
|
"read_error threshold [cur %d:max %d]\n",
|
|
mdname(mddev), b,
|
|
atomic_read(&rdev->read_errors), max_read_errors);
|
|
printk(KERN_NOTICE
|
|
"md/raid10:%s: %s: Failing raid device\n",
|
|
mdname(mddev), b);
|
|
md_error(mddev, conf->mirrors[d].rdev);
|
|
return;
|
|
}
|
|
|
|
while(sectors) {
|
|
int s = sectors;
|
|
int sl = r10_bio->read_slot;
|
|
int success = 0;
|
|
int start;
|
|
|
|
if (s > (PAGE_SIZE>>9))
|
|
s = PAGE_SIZE >> 9;
|
|
|
|
rcu_read_lock();
|
|
do {
|
|
sector_t first_bad;
|
|
int bad_sectors;
|
|
|
|
d = r10_bio->devs[sl].devnum;
|
|
rdev = rcu_dereference(conf->mirrors[d].rdev);
|
|
if (rdev &&
|
|
test_bit(In_sync, &rdev->flags) &&
|
|
is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
|
|
&first_bad, &bad_sectors) == 0) {
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
success = sync_page_io(rdev,
|
|
r10_bio->devs[sl].addr +
|
|
sect,
|
|
s<<9,
|
|
conf->tmppage, READ, false);
|
|
rdev_dec_pending(rdev, mddev);
|
|
rcu_read_lock();
|
|
if (success)
|
|
break;
|
|
}
|
|
sl++;
|
|
if (sl == conf->copies)
|
|
sl = 0;
|
|
} while (!success && sl != r10_bio->read_slot);
|
|
rcu_read_unlock();
|
|
|
|
if (!success) {
|
|
/* Cannot read from anywhere, just mark the block
|
|
* as bad on the first device to discourage future
|
|
* reads.
|
|
*/
|
|
int dn = r10_bio->devs[r10_bio->read_slot].devnum;
|
|
rdev = conf->mirrors[dn].rdev;
|
|
|
|
if (!rdev_set_badblocks(
|
|
rdev,
|
|
r10_bio->devs[r10_bio->read_slot].addr
|
|
+ sect,
|
|
s, 0))
|
|
md_error(mddev, rdev);
|
|
break;
|
|
}
|
|
|
|
start = sl;
|
|
/* write it back and re-read */
|
|
rcu_read_lock();
|
|
while (sl != r10_bio->read_slot) {
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
if (sl==0)
|
|
sl = conf->copies;
|
|
sl--;
|
|
d = r10_bio->devs[sl].devnum;
|
|
rdev = rcu_dereference(conf->mirrors[d].rdev);
|
|
if (!rdev ||
|
|
!test_bit(In_sync, &rdev->flags))
|
|
continue;
|
|
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
if (r10_sync_page_io(rdev,
|
|
r10_bio->devs[sl].addr +
|
|
sect,
|
|
s<<9, conf->tmppage, WRITE)
|
|
== 0) {
|
|
/* Well, this device is dead */
|
|
printk(KERN_NOTICE
|
|
"md/raid10:%s: read correction "
|
|
"write failed"
|
|
" (%d sectors at %llu on %s)\n",
|
|
mdname(mddev), s,
|
|
(unsigned long long)(
|
|
sect + rdev->data_offset),
|
|
bdevname(rdev->bdev, b));
|
|
printk(KERN_NOTICE "md/raid10:%s: %s: failing "
|
|
"drive\n",
|
|
mdname(mddev),
|
|
bdevname(rdev->bdev, b));
|
|
}
|
|
rdev_dec_pending(rdev, mddev);
|
|
rcu_read_lock();
|
|
}
|
|
sl = start;
|
|
while (sl != r10_bio->read_slot) {
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
if (sl==0)
|
|
sl = conf->copies;
|
|
sl--;
|
|
d = r10_bio->devs[sl].devnum;
|
|
rdev = rcu_dereference(conf->mirrors[d].rdev);
|
|
if (!rdev ||
|
|
!test_bit(In_sync, &rdev->flags))
|
|
continue;
|
|
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
switch (r10_sync_page_io(rdev,
|
|
r10_bio->devs[sl].addr +
|
|
sect,
|
|
s<<9, conf->tmppage,
|
|
READ)) {
|
|
case 0:
|
|
/* Well, this device is dead */
|
|
printk(KERN_NOTICE
|
|
"md/raid10:%s: unable to read back "
|
|
"corrected sectors"
|
|
" (%d sectors at %llu on %s)\n",
|
|
mdname(mddev), s,
|
|
(unsigned long long)(
|
|
sect + rdev->data_offset),
|
|
bdevname(rdev->bdev, b));
|
|
printk(KERN_NOTICE "md/raid10:%s: %s: failing "
|
|
"drive\n",
|
|
mdname(mddev),
|
|
bdevname(rdev->bdev, b));
|
|
break;
|
|
case 1:
|
|
printk(KERN_INFO
|
|
"md/raid10:%s: read error corrected"
|
|
" (%d sectors at %llu on %s)\n",
|
|
mdname(mddev), s,
|
|
(unsigned long long)(
|
|
sect + rdev->data_offset),
|
|
bdevname(rdev->bdev, b));
|
|
atomic_add(s, &rdev->corrected_errors);
|
|
}
|
|
|
|
rdev_dec_pending(rdev, mddev);
|
|
rcu_read_lock();
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
sectors -= s;
|
|
sect += s;
|
|
}
|
|
}
|
|
|
|
static void bi_complete(struct bio *bio, int error)
|
|
{
|
|
complete((struct completion *)bio->bi_private);
|
|
}
|
|
|
|
static int submit_bio_wait(int rw, struct bio *bio)
|
|
{
|
|
struct completion event;
|
|
rw |= REQ_SYNC;
|
|
|
|
init_completion(&event);
|
|
bio->bi_private = &event;
|
|
bio->bi_end_io = bi_complete;
|
|
submit_bio(rw, bio);
|
|
wait_for_completion(&event);
|
|
|
|
return test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
}
|
|
|
|
static int narrow_write_error(struct r10bio *r10_bio, int i)
|
|
{
|
|
struct bio *bio = r10_bio->master_bio;
|
|
struct mddev *mddev = r10_bio->mddev;
|
|
struct r10conf *conf = mddev->private;
|
|
struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
|
|
/* bio has the data to be written to slot 'i' where
|
|
* we just recently had a write error.
|
|
* We repeatedly clone the bio and trim down to one block,
|
|
* then try the write. Where the write fails we record
|
|
* a bad block.
|
|
* It is conceivable that the bio doesn't exactly align with
|
|
* blocks. We must handle this.
|
|
*
|
|
* We currently own a reference to the rdev.
|
|
*/
|
|
|
|
int block_sectors;
|
|
sector_t sector;
|
|
int sectors;
|
|
int sect_to_write = r10_bio->sectors;
|
|
int ok = 1;
|
|
|
|
if (rdev->badblocks.shift < 0)
|
|
return 0;
|
|
|
|
block_sectors = 1 << rdev->badblocks.shift;
|
|
sector = r10_bio->sector;
|
|
sectors = ((r10_bio->sector + block_sectors)
|
|
& ~(sector_t)(block_sectors - 1))
|
|
- sector;
|
|
|
|
while (sect_to_write) {
|
|
struct bio *wbio;
|
|
if (sectors > sect_to_write)
|
|
sectors = sect_to_write;
|
|
/* Write at 'sector' for 'sectors' */
|
|
wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
|
|
md_trim_bio(wbio, sector - bio->bi_sector, sectors);
|
|
wbio->bi_sector = (r10_bio->devs[i].addr+
|
|
rdev->data_offset+
|
|
(sector - r10_bio->sector));
|
|
wbio->bi_bdev = rdev->bdev;
|
|
if (submit_bio_wait(WRITE, wbio) == 0)
|
|
/* Failure! */
|
|
ok = rdev_set_badblocks(rdev, sector,
|
|
sectors, 0)
|
|
&& ok;
|
|
|
|
bio_put(wbio);
|
|
sect_to_write -= sectors;
|
|
sector += sectors;
|
|
sectors = block_sectors;
|
|
}
|
|
return ok;
|
|
}
|
|
|
|
static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
|
|
{
|
|
int slot = r10_bio->read_slot;
|
|
struct bio *bio;
|
|
struct r10conf *conf = mddev->private;
|
|
struct md_rdev *rdev = r10_bio->devs[slot].rdev;
|
|
char b[BDEVNAME_SIZE];
|
|
unsigned long do_sync;
|
|
int max_sectors;
|
|
|
|
/* we got a read error. Maybe the drive is bad. Maybe just
|
|
* the block and we can fix it.
|
|
* We freeze all other IO, and try reading the block from
|
|
* other devices. When we find one, we re-write
|
|
* and check it that fixes the read error.
|
|
* This is all done synchronously while the array is
|
|
* frozen.
|
|
*/
|
|
if (mddev->ro == 0) {
|
|
freeze_array(conf);
|
|
fix_read_error(conf, mddev, r10_bio);
|
|
unfreeze_array(conf);
|
|
}
|
|
rdev_dec_pending(rdev, mddev);
|
|
|
|
bio = r10_bio->devs[slot].bio;
|
|
bdevname(bio->bi_bdev, b);
|
|
r10_bio->devs[slot].bio =
|
|
mddev->ro ? IO_BLOCKED : NULL;
|
|
read_more:
|
|
rdev = read_balance(conf, r10_bio, &max_sectors);
|
|
if (rdev == NULL) {
|
|
printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
|
|
" read error for block %llu\n",
|
|
mdname(mddev), b,
|
|
(unsigned long long)r10_bio->sector);
|
|
raid_end_bio_io(r10_bio);
|
|
bio_put(bio);
|
|
return;
|
|
}
|
|
|
|
do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
|
|
if (bio)
|
|
bio_put(bio);
|
|
slot = r10_bio->read_slot;
|
|
printk_ratelimited(
|
|
KERN_ERR
|
|
"md/raid10:%s: %s: redirecting"
|
|
"sector %llu to another mirror\n",
|
|
mdname(mddev),
|
|
bdevname(rdev->bdev, b),
|
|
(unsigned long long)r10_bio->sector);
|
|
bio = bio_clone_mddev(r10_bio->master_bio,
|
|
GFP_NOIO, mddev);
|
|
md_trim_bio(bio,
|
|
r10_bio->sector - bio->bi_sector,
|
|
max_sectors);
|
|
r10_bio->devs[slot].bio = bio;
|
|
r10_bio->devs[slot].rdev = rdev;
|
|
bio->bi_sector = r10_bio->devs[slot].addr
|
|
+ rdev->data_offset;
|
|
bio->bi_bdev = rdev->bdev;
|
|
bio->bi_rw = READ | do_sync;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = raid10_end_read_request;
|
|
if (max_sectors < r10_bio->sectors) {
|
|
/* Drat - have to split this up more */
|
|
struct bio *mbio = r10_bio->master_bio;
|
|
int sectors_handled =
|
|
r10_bio->sector + max_sectors
|
|
- mbio->bi_sector;
|
|
r10_bio->sectors = max_sectors;
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (mbio->bi_phys_segments == 0)
|
|
mbio->bi_phys_segments = 2;
|
|
else
|
|
mbio->bi_phys_segments++;
|
|
spin_unlock_irq(&conf->device_lock);
|
|
generic_make_request(bio);
|
|
bio = NULL;
|
|
|
|
r10_bio = mempool_alloc(conf->r10bio_pool,
|
|
GFP_NOIO);
|
|
r10_bio->master_bio = mbio;
|
|
r10_bio->sectors = (mbio->bi_size >> 9)
|
|
- sectors_handled;
|
|
r10_bio->state = 0;
|
|
set_bit(R10BIO_ReadError,
|
|
&r10_bio->state);
|
|
r10_bio->mddev = mddev;
|
|
r10_bio->sector = mbio->bi_sector
|
|
+ sectors_handled;
|
|
|
|
goto read_more;
|
|
} else
|
|
generic_make_request(bio);
|
|
}
|
|
|
|
static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
|
|
{
|
|
/* Some sort of write request has finished and it
|
|
* succeeded in writing where we thought there was a
|
|
* bad block. So forget the bad block.
|
|
* Or possibly if failed and we need to record
|
|
* a bad block.
|
|
*/
|
|
int m;
|
|
struct md_rdev *rdev;
|
|
|
|
if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
|
|
test_bit(R10BIO_IsRecover, &r10_bio->state)) {
|
|
for (m = 0; m < conf->copies; m++) {
|
|
int dev = r10_bio->devs[m].devnum;
|
|
rdev = conf->mirrors[dev].rdev;
|
|
if (r10_bio->devs[m].bio == NULL)
|
|
continue;
|
|
if (test_bit(BIO_UPTODATE,
|
|
&r10_bio->devs[m].bio->bi_flags)) {
|
|
rdev_clear_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors);
|
|
} else {
|
|
if (!rdev_set_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors, 0))
|
|
md_error(conf->mddev, rdev);
|
|
}
|
|
rdev = conf->mirrors[dev].replacement;
|
|
if (r10_bio->devs[m].repl_bio == NULL)
|
|
continue;
|
|
if (test_bit(BIO_UPTODATE,
|
|
&r10_bio->devs[m].repl_bio->bi_flags)) {
|
|
rdev_clear_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors);
|
|
} else {
|
|
if (!rdev_set_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors, 0))
|
|
md_error(conf->mddev, rdev);
|
|
}
|
|
}
|
|
put_buf(r10_bio);
|
|
} else {
|
|
for (m = 0; m < conf->copies; m++) {
|
|
int dev = r10_bio->devs[m].devnum;
|
|
struct bio *bio = r10_bio->devs[m].bio;
|
|
rdev = conf->mirrors[dev].rdev;
|
|
if (bio == IO_MADE_GOOD) {
|
|
rdev_clear_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors);
|
|
rdev_dec_pending(rdev, conf->mddev);
|
|
} else if (bio != NULL &&
|
|
!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
|
|
if (!narrow_write_error(r10_bio, m)) {
|
|
md_error(conf->mddev, rdev);
|
|
set_bit(R10BIO_Degraded,
|
|
&r10_bio->state);
|
|
}
|
|
rdev_dec_pending(rdev, conf->mddev);
|
|
}
|
|
bio = r10_bio->devs[m].repl_bio;
|
|
rdev = conf->mirrors[dev].replacement;
|
|
if (rdev && bio == IO_MADE_GOOD) {
|
|
rdev_clear_badblocks(
|
|
rdev,
|
|
r10_bio->devs[m].addr,
|
|
r10_bio->sectors);
|
|
rdev_dec_pending(rdev, conf->mddev);
|
|
}
|
|
}
|
|
if (test_bit(R10BIO_WriteError,
|
|
&r10_bio->state))
|
|
close_write(r10_bio);
|
|
raid_end_bio_io(r10_bio);
|
|
}
|
|
}
|
|
|
|
static void raid10d(struct mddev *mddev)
|
|
{
|
|
struct r10bio *r10_bio;
|
|
unsigned long flags;
|
|
struct r10conf *conf = mddev->private;
|
|
struct list_head *head = &conf->retry_list;
|
|
struct blk_plug plug;
|
|
|
|
md_check_recovery(mddev);
|
|
|
|
blk_start_plug(&plug);
|
|
for (;;) {
|
|
|
|
flush_pending_writes(conf);
|
|
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
if (list_empty(head)) {
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
break;
|
|
}
|
|
r10_bio = list_entry(head->prev, struct r10bio, retry_list);
|
|
list_del(head->prev);
|
|
conf->nr_queued--;
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
|
|
mddev = r10_bio->mddev;
|
|
conf = mddev->private;
|
|
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
|
|
test_bit(R10BIO_WriteError, &r10_bio->state))
|
|
handle_write_completed(conf, r10_bio);
|
|
else if (test_bit(R10BIO_IsSync, &r10_bio->state))
|
|
sync_request_write(mddev, r10_bio);
|
|
else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
|
|
recovery_request_write(mddev, r10_bio);
|
|
else if (test_bit(R10BIO_ReadError, &r10_bio->state))
|
|
handle_read_error(mddev, r10_bio);
|
|
else {
|
|
/* just a partial read to be scheduled from a
|
|
* separate context
|
|
*/
|
|
int slot = r10_bio->read_slot;
|
|
generic_make_request(r10_bio->devs[slot].bio);
|
|
}
|
|
|
|
cond_resched();
|
|
if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
|
|
md_check_recovery(mddev);
|
|
}
|
|
blk_finish_plug(&plug);
|
|
}
|
|
|
|
|
|
static int init_resync(struct r10conf *conf)
|
|
{
|
|
int buffs;
|
|
int i;
|
|
|
|
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
|
|
BUG_ON(conf->r10buf_pool);
|
|
conf->have_replacement = 0;
|
|
for (i = 0; i < conf->raid_disks; i++)
|
|
if (conf->mirrors[i].replacement)
|
|
conf->have_replacement = 1;
|
|
conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
|
|
if (!conf->r10buf_pool)
|
|
return -ENOMEM;
|
|
conf->next_resync = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* perform a "sync" on one "block"
|
|
*
|
|
* We need to make sure that no normal I/O request - particularly write
|
|
* requests - conflict with active sync requests.
|
|
*
|
|
* This is achieved by tracking pending requests and a 'barrier' concept
|
|
* that can be installed to exclude normal IO requests.
|
|
*
|
|
* Resync and recovery are handled very differently.
|
|
* We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
|
|
*
|
|
* For resync, we iterate over virtual addresses, read all copies,
|
|
* and update if there are differences. If only one copy is live,
|
|
* skip it.
|
|
* For recovery, we iterate over physical addresses, read a good
|
|
* value for each non-in_sync drive, and over-write.
|
|
*
|
|
* So, for recovery we may have several outstanding complex requests for a
|
|
* given address, one for each out-of-sync device. We model this by allocating
|
|
* a number of r10_bio structures, one for each out-of-sync device.
|
|
* As we setup these structures, we collect all bio's together into a list
|
|
* which we then process collectively to add pages, and then process again
|
|
* to pass to generic_make_request.
|
|
*
|
|
* The r10_bio structures are linked using a borrowed master_bio pointer.
|
|
* This link is counted in ->remaining. When the r10_bio that points to NULL
|
|
* has its remaining count decremented to 0, the whole complex operation
|
|
* is complete.
|
|
*
|
|
*/
|
|
|
|
static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
|
|
int *skipped, int go_faster)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
struct r10bio *r10_bio;
|
|
struct bio *biolist = NULL, *bio;
|
|
sector_t max_sector, nr_sectors;
|
|
int i;
|
|
int max_sync;
|
|
sector_t sync_blocks;
|
|
sector_t sectors_skipped = 0;
|
|
int chunks_skipped = 0;
|
|
|
|
if (!conf->r10buf_pool)
|
|
if (init_resync(conf))
|
|
return 0;
|
|
|
|
skipped:
|
|
max_sector = mddev->dev_sectors;
|
|
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
|
|
max_sector = mddev->resync_max_sectors;
|
|
if (sector_nr >= max_sector) {
|
|
/* If we aborted, we need to abort the
|
|
* sync on the 'current' bitmap chucks (there can
|
|
* be several when recovering multiple devices).
|
|
* as we may have started syncing it but not finished.
|
|
* We can find the current address in
|
|
* mddev->curr_resync, but for recovery,
|
|
* we need to convert that to several
|
|
* virtual addresses.
|
|
*/
|
|
if (mddev->curr_resync < max_sector) { /* aborted */
|
|
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
|
|
bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
|
|
&sync_blocks, 1);
|
|
else for (i=0; i<conf->raid_disks; i++) {
|
|
sector_t sect =
|
|
raid10_find_virt(conf, mddev->curr_resync, i);
|
|
bitmap_end_sync(mddev->bitmap, sect,
|
|
&sync_blocks, 1);
|
|
}
|
|
} else {
|
|
/* completed sync */
|
|
if ((!mddev->bitmap || conf->fullsync)
|
|
&& conf->have_replacement
|
|
&& test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
|
|
/* Completed a full sync so the replacements
|
|
* are now fully recovered.
|
|
*/
|
|
for (i = 0; i < conf->raid_disks; i++)
|
|
if (conf->mirrors[i].replacement)
|
|
conf->mirrors[i].replacement
|
|
->recovery_offset
|
|
= MaxSector;
|
|
}
|
|
conf->fullsync = 0;
|
|
}
|
|
bitmap_close_sync(mddev->bitmap);
|
|
close_sync(conf);
|
|
*skipped = 1;
|
|
return sectors_skipped;
|
|
}
|
|
if (chunks_skipped >= conf->raid_disks) {
|
|
/* if there has been nothing to do on any drive,
|
|
* then there is nothing to do at all..
|
|
*/
|
|
*skipped = 1;
|
|
return (max_sector - sector_nr) + sectors_skipped;
|
|
}
|
|
|
|
if (max_sector > mddev->resync_max)
|
|
max_sector = mddev->resync_max; /* Don't do IO beyond here */
|
|
|
|
/* make sure whole request will fit in a chunk - if chunks
|
|
* are meaningful
|
|
*/
|
|
if (conf->near_copies < conf->raid_disks &&
|
|
max_sector > (sector_nr | conf->chunk_mask))
|
|
max_sector = (sector_nr | conf->chunk_mask) + 1;
|
|
/*
|
|
* If there is non-resync activity waiting for us then
|
|
* put in a delay to throttle resync.
|
|
*/
|
|
if (!go_faster && conf->nr_waiting)
|
|
msleep_interruptible(1000);
|
|
|
|
/* Again, very different code for resync and recovery.
|
|
* Both must result in an r10bio with a list of bios that
|
|
* have bi_end_io, bi_sector, bi_bdev set,
|
|
* and bi_private set to the r10bio.
|
|
* For recovery, we may actually create several r10bios
|
|
* with 2 bios in each, that correspond to the bios in the main one.
|
|
* In this case, the subordinate r10bios link back through a
|
|
* borrowed master_bio pointer, and the counter in the master
|
|
* includes a ref from each subordinate.
|
|
*/
|
|
/* First, we decide what to do and set ->bi_end_io
|
|
* To end_sync_read if we want to read, and
|
|
* end_sync_write if we will want to write.
|
|
*/
|
|
|
|
max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
|
|
if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
|
|
/* recovery... the complicated one */
|
|
int j;
|
|
r10_bio = NULL;
|
|
|
|
for (i=0 ; i<conf->raid_disks; i++) {
|
|
int still_degraded;
|
|
struct r10bio *rb2;
|
|
sector_t sect;
|
|
int must_sync;
|
|
int any_working;
|
|
struct mirror_info *mirror = &conf->mirrors[i];
|
|
|
|
if ((mirror->rdev == NULL ||
|
|
test_bit(In_sync, &mirror->rdev->flags))
|
|
&&
|
|
(mirror->replacement == NULL ||
|
|
test_bit(Faulty,
|
|
&mirror->replacement->flags)))
|
|
continue;
|
|
|
|
still_degraded = 0;
|
|
/* want to reconstruct this device */
|
|
rb2 = r10_bio;
|
|
sect = raid10_find_virt(conf, sector_nr, i);
|
|
/* Unless we are doing a full sync, or a replacement
|
|
* we only need to recover the block if it is set in
|
|
* the bitmap
|
|
*/
|
|
must_sync = bitmap_start_sync(mddev->bitmap, sect,
|
|
&sync_blocks, 1);
|
|
if (sync_blocks < max_sync)
|
|
max_sync = sync_blocks;
|
|
if (!must_sync &&
|
|
mirror->replacement == NULL &&
|
|
!conf->fullsync) {
|
|
/* yep, skip the sync_blocks here, but don't assume
|
|
* that there will never be anything to do here
|
|
*/
|
|
chunks_skipped = -1;
|
|
continue;
|
|
}
|
|
|
|
r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
|
|
raise_barrier(conf, rb2 != NULL);
|
|
atomic_set(&r10_bio->remaining, 0);
|
|
|
|
r10_bio->master_bio = (struct bio*)rb2;
|
|
if (rb2)
|
|
atomic_inc(&rb2->remaining);
|
|
r10_bio->mddev = mddev;
|
|
set_bit(R10BIO_IsRecover, &r10_bio->state);
|
|
r10_bio->sector = sect;
|
|
|
|
raid10_find_phys(conf, r10_bio);
|
|
|
|
/* Need to check if the array will still be
|
|
* degraded
|
|
*/
|
|
for (j=0; j<conf->raid_disks; j++)
|
|
if (conf->mirrors[j].rdev == NULL ||
|
|
test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
|
|
still_degraded = 1;
|
|
break;
|
|
}
|
|
|
|
must_sync = bitmap_start_sync(mddev->bitmap, sect,
|
|
&sync_blocks, still_degraded);
|
|
|
|
any_working = 0;
|
|
for (j=0; j<conf->copies;j++) {
|
|
int k;
|
|
int d = r10_bio->devs[j].devnum;
|
|
sector_t from_addr, to_addr;
|
|
struct md_rdev *rdev;
|
|
sector_t sector, first_bad;
|
|
int bad_sectors;
|
|
if (!conf->mirrors[d].rdev ||
|
|
!test_bit(In_sync, &conf->mirrors[d].rdev->flags))
|
|
continue;
|
|
/* This is where we read from */
|
|
any_working = 1;
|
|
rdev = conf->mirrors[d].rdev;
|
|
sector = r10_bio->devs[j].addr;
|
|
|
|
if (is_badblock(rdev, sector, max_sync,
|
|
&first_bad, &bad_sectors)) {
|
|
if (first_bad > sector)
|
|
max_sync = first_bad - sector;
|
|
else {
|
|
bad_sectors -= (sector
|
|
- first_bad);
|
|
if (max_sync > bad_sectors)
|
|
max_sync = bad_sectors;
|
|
continue;
|
|
}
|
|
}
|
|
bio = r10_bio->devs[0].bio;
|
|
bio->bi_next = biolist;
|
|
biolist = bio;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = end_sync_read;
|
|
bio->bi_rw = READ;
|
|
from_addr = r10_bio->devs[j].addr;
|
|
bio->bi_sector = from_addr + rdev->data_offset;
|
|
bio->bi_bdev = rdev->bdev;
|
|
atomic_inc(&rdev->nr_pending);
|
|
/* and we write to 'i' (if not in_sync) */
|
|
|
|
for (k=0; k<conf->copies; k++)
|
|
if (r10_bio->devs[k].devnum == i)
|
|
break;
|
|
BUG_ON(k == conf->copies);
|
|
to_addr = r10_bio->devs[k].addr;
|
|
r10_bio->devs[0].devnum = d;
|
|
r10_bio->devs[0].addr = from_addr;
|
|
r10_bio->devs[1].devnum = i;
|
|
r10_bio->devs[1].addr = to_addr;
|
|
|
|
rdev = mirror->rdev;
|
|
if (!test_bit(In_sync, &rdev->flags)) {
|
|
bio = r10_bio->devs[1].bio;
|
|
bio->bi_next = biolist;
|
|
biolist = bio;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = end_sync_write;
|
|
bio->bi_rw = WRITE;
|
|
bio->bi_sector = to_addr
|
|
+ rdev->data_offset;
|
|
bio->bi_bdev = rdev->bdev;
|
|
atomic_inc(&r10_bio->remaining);
|
|
} else
|
|
r10_bio->devs[1].bio->bi_end_io = NULL;
|
|
|
|
/* and maybe write to replacement */
|
|
bio = r10_bio->devs[1].repl_bio;
|
|
if (bio)
|
|
bio->bi_end_io = NULL;
|
|
rdev = mirror->replacement;
|
|
/* Note: if rdev != NULL, then bio
|
|
* cannot be NULL as r10buf_pool_alloc will
|
|
* have allocated it.
|
|
* So the second test here is pointless.
|
|
* But it keeps semantic-checkers happy, and
|
|
* this comment keeps human reviewers
|
|
* happy.
|
|
*/
|
|
if (rdev == NULL || bio == NULL ||
|
|
test_bit(Faulty, &rdev->flags))
|
|
break;
|
|
bio->bi_next = biolist;
|
|
biolist = bio;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = end_sync_write;
|
|
bio->bi_rw = WRITE;
|
|
bio->bi_sector = to_addr + rdev->data_offset;
|
|
bio->bi_bdev = rdev->bdev;
|
|
atomic_inc(&r10_bio->remaining);
|
|
break;
|
|
}
|
|
if (j == conf->copies) {
|
|
/* Cannot recover, so abort the recovery or
|
|
* record a bad block */
|
|
put_buf(r10_bio);
|
|
if (rb2)
|
|
atomic_dec(&rb2->remaining);
|
|
r10_bio = rb2;
|
|
if (any_working) {
|
|
/* problem is that there are bad blocks
|
|
* on other device(s)
|
|
*/
|
|
int k;
|
|
for (k = 0; k < conf->copies; k++)
|
|
if (r10_bio->devs[k].devnum == i)
|
|
break;
|
|
if (!test_bit(In_sync,
|
|
&mirror->rdev->flags)
|
|
&& !rdev_set_badblocks(
|
|
mirror->rdev,
|
|
r10_bio->devs[k].addr,
|
|
max_sync, 0))
|
|
any_working = 0;
|
|
if (mirror->replacement &&
|
|
!rdev_set_badblocks(
|
|
mirror->replacement,
|
|
r10_bio->devs[k].addr,
|
|
max_sync, 0))
|
|
any_working = 0;
|
|
}
|
|
if (!any_working) {
|
|
if (!test_and_set_bit(MD_RECOVERY_INTR,
|
|
&mddev->recovery))
|
|
printk(KERN_INFO "md/raid10:%s: insufficient "
|
|
"working devices for recovery.\n",
|
|
mdname(mddev));
|
|
mirror->recovery_disabled
|
|
= mddev->recovery_disabled;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (biolist == NULL) {
|
|
while (r10_bio) {
|
|
struct r10bio *rb2 = r10_bio;
|
|
r10_bio = (struct r10bio*) rb2->master_bio;
|
|
rb2->master_bio = NULL;
|
|
put_buf(rb2);
|
|
}
|
|
goto giveup;
|
|
}
|
|
} else {
|
|
/* resync. Schedule a read for every block at this virt offset */
|
|
int count = 0;
|
|
|
|
bitmap_cond_end_sync(mddev->bitmap, sector_nr);
|
|
|
|
if (!bitmap_start_sync(mddev->bitmap, sector_nr,
|
|
&sync_blocks, mddev->degraded) &&
|
|
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
|
|
&mddev->recovery)) {
|
|
/* We can skip this block */
|
|
*skipped = 1;
|
|
return sync_blocks + sectors_skipped;
|
|
}
|
|
if (sync_blocks < max_sync)
|
|
max_sync = sync_blocks;
|
|
r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
|
|
|
|
r10_bio->mddev = mddev;
|
|
atomic_set(&r10_bio->remaining, 0);
|
|
raise_barrier(conf, 0);
|
|
conf->next_resync = sector_nr;
|
|
|
|
r10_bio->master_bio = NULL;
|
|
r10_bio->sector = sector_nr;
|
|
set_bit(R10BIO_IsSync, &r10_bio->state);
|
|
raid10_find_phys(conf, r10_bio);
|
|
r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
|
|
|
|
for (i=0; i<conf->copies; i++) {
|
|
int d = r10_bio->devs[i].devnum;
|
|
sector_t first_bad, sector;
|
|
int bad_sectors;
|
|
|
|
if (r10_bio->devs[i].repl_bio)
|
|
r10_bio->devs[i].repl_bio->bi_end_io = NULL;
|
|
|
|
bio = r10_bio->devs[i].bio;
|
|
bio->bi_end_io = NULL;
|
|
clear_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
if (conf->mirrors[d].rdev == NULL ||
|
|
test_bit(Faulty, &conf->mirrors[d].rdev->flags))
|
|
continue;
|
|
sector = r10_bio->devs[i].addr;
|
|
if (is_badblock(conf->mirrors[d].rdev,
|
|
sector, max_sync,
|
|
&first_bad, &bad_sectors)) {
|
|
if (first_bad > sector)
|
|
max_sync = first_bad - sector;
|
|
else {
|
|
bad_sectors -= (sector - first_bad);
|
|
if (max_sync > bad_sectors)
|
|
max_sync = max_sync;
|
|
continue;
|
|
}
|
|
}
|
|
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
|
|
atomic_inc(&r10_bio->remaining);
|
|
bio->bi_next = biolist;
|
|
biolist = bio;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = end_sync_read;
|
|
bio->bi_rw = READ;
|
|
bio->bi_sector = sector +
|
|
conf->mirrors[d].rdev->data_offset;
|
|
bio->bi_bdev = conf->mirrors[d].rdev->bdev;
|
|
count++;
|
|
|
|
if (conf->mirrors[d].replacement == NULL ||
|
|
test_bit(Faulty,
|
|
&conf->mirrors[d].replacement->flags))
|
|
continue;
|
|
|
|
/* Need to set up for writing to the replacement */
|
|
bio = r10_bio->devs[i].repl_bio;
|
|
clear_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
|
|
sector = r10_bio->devs[i].addr;
|
|
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
|
|
bio->bi_next = biolist;
|
|
biolist = bio;
|
|
bio->bi_private = r10_bio;
|
|
bio->bi_end_io = end_sync_write;
|
|
bio->bi_rw = WRITE;
|
|
bio->bi_sector = sector +
|
|
conf->mirrors[d].replacement->data_offset;
|
|
bio->bi_bdev = conf->mirrors[d].replacement->bdev;
|
|
count++;
|
|
}
|
|
|
|
if (count < 2) {
|
|
for (i=0; i<conf->copies; i++) {
|
|
int d = r10_bio->devs[i].devnum;
|
|
if (r10_bio->devs[i].bio->bi_end_io)
|
|
rdev_dec_pending(conf->mirrors[d].rdev,
|
|
mddev);
|
|
if (r10_bio->devs[i].repl_bio &&
|
|
r10_bio->devs[i].repl_bio->bi_end_io)
|
|
rdev_dec_pending(
|
|
conf->mirrors[d].replacement,
|
|
mddev);
|
|
}
|
|
put_buf(r10_bio);
|
|
biolist = NULL;
|
|
goto giveup;
|
|
}
|
|
}
|
|
|
|
for (bio = biolist; bio ; bio=bio->bi_next) {
|
|
|
|
bio->bi_flags &= ~(BIO_POOL_MASK - 1);
|
|
if (bio->bi_end_io)
|
|
bio->bi_flags |= 1 << BIO_UPTODATE;
|
|
bio->bi_vcnt = 0;
|
|
bio->bi_idx = 0;
|
|
bio->bi_phys_segments = 0;
|
|
bio->bi_size = 0;
|
|
}
|
|
|
|
nr_sectors = 0;
|
|
if (sector_nr + max_sync < max_sector)
|
|
max_sector = sector_nr + max_sync;
|
|
do {
|
|
struct page *page;
|
|
int len = PAGE_SIZE;
|
|
if (sector_nr + (len>>9) > max_sector)
|
|
len = (max_sector - sector_nr) << 9;
|
|
if (len == 0)
|
|
break;
|
|
for (bio= biolist ; bio ; bio=bio->bi_next) {
|
|
struct bio *bio2;
|
|
page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
|
|
if (bio_add_page(bio, page, len, 0))
|
|
continue;
|
|
|
|
/* stop here */
|
|
bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
|
|
for (bio2 = biolist;
|
|
bio2 && bio2 != bio;
|
|
bio2 = bio2->bi_next) {
|
|
/* remove last page from this bio */
|
|
bio2->bi_vcnt--;
|
|
bio2->bi_size -= len;
|
|
bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
|
|
}
|
|
goto bio_full;
|
|
}
|
|
nr_sectors += len>>9;
|
|
sector_nr += len>>9;
|
|
} while (biolist->bi_vcnt < RESYNC_PAGES);
|
|
bio_full:
|
|
r10_bio->sectors = nr_sectors;
|
|
|
|
while (biolist) {
|
|
bio = biolist;
|
|
biolist = biolist->bi_next;
|
|
|
|
bio->bi_next = NULL;
|
|
r10_bio = bio->bi_private;
|
|
r10_bio->sectors = nr_sectors;
|
|
|
|
if (bio->bi_end_io == end_sync_read) {
|
|
md_sync_acct(bio->bi_bdev, nr_sectors);
|
|
generic_make_request(bio);
|
|
}
|
|
}
|
|
|
|
if (sectors_skipped)
|
|
/* pretend they weren't skipped, it makes
|
|
* no important difference in this case
|
|
*/
|
|
md_done_sync(mddev, sectors_skipped, 1);
|
|
|
|
return sectors_skipped + nr_sectors;
|
|
giveup:
|
|
/* There is nowhere to write, so all non-sync
|
|
* drives must be failed or in resync, all drives
|
|
* have a bad block, so try the next chunk...
|
|
*/
|
|
if (sector_nr + max_sync < max_sector)
|
|
max_sector = sector_nr + max_sync;
|
|
|
|
sectors_skipped += (max_sector - sector_nr);
|
|
chunks_skipped ++;
|
|
sector_nr = max_sector;
|
|
goto skipped;
|
|
}
|
|
|
|
static sector_t
|
|
raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
|
|
{
|
|
sector_t size;
|
|
struct r10conf *conf = mddev->private;
|
|
|
|
if (!raid_disks)
|
|
raid_disks = conf->raid_disks;
|
|
if (!sectors)
|
|
sectors = conf->dev_sectors;
|
|
|
|
size = sectors >> conf->chunk_shift;
|
|
sector_div(size, conf->far_copies);
|
|
size = size * raid_disks;
|
|
sector_div(size, conf->near_copies);
|
|
|
|
return size << conf->chunk_shift;
|
|
}
|
|
|
|
|
|
static struct r10conf *setup_conf(struct mddev *mddev)
|
|
{
|
|
struct r10conf *conf = NULL;
|
|
int nc, fc, fo;
|
|
sector_t stride, size;
|
|
int err = -EINVAL;
|
|
|
|
if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
|
|
!is_power_of_2(mddev->new_chunk_sectors)) {
|
|
printk(KERN_ERR "md/raid10:%s: chunk size must be "
|
|
"at least PAGE_SIZE(%ld) and be a power of 2.\n",
|
|
mdname(mddev), PAGE_SIZE);
|
|
goto out;
|
|
}
|
|
|
|
nc = mddev->new_layout & 255;
|
|
fc = (mddev->new_layout >> 8) & 255;
|
|
fo = mddev->new_layout & (1<<16);
|
|
|
|
if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
|
|
(mddev->new_layout >> 17)) {
|
|
printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
|
|
mdname(mddev), mddev->new_layout);
|
|
goto out;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
|
|
if (!conf)
|
|
goto out;
|
|
|
|
conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
|
|
GFP_KERNEL);
|
|
if (!conf->mirrors)
|
|
goto out;
|
|
|
|
conf->tmppage = alloc_page(GFP_KERNEL);
|
|
if (!conf->tmppage)
|
|
goto out;
|
|
|
|
|
|
conf->raid_disks = mddev->raid_disks;
|
|
conf->near_copies = nc;
|
|
conf->far_copies = fc;
|
|
conf->copies = nc*fc;
|
|
conf->far_offset = fo;
|
|
conf->chunk_mask = mddev->new_chunk_sectors - 1;
|
|
conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
|
|
|
|
conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
|
|
r10bio_pool_free, conf);
|
|
if (!conf->r10bio_pool)
|
|
goto out;
|
|
|
|
size = mddev->dev_sectors >> conf->chunk_shift;
|
|
sector_div(size, fc);
|
|
size = size * conf->raid_disks;
|
|
sector_div(size, nc);
|
|
/* 'size' is now the number of chunks in the array */
|
|
/* calculate "used chunks per device" in 'stride' */
|
|
stride = size * conf->copies;
|
|
|
|
/* We need to round up when dividing by raid_disks to
|
|
* get the stride size.
|
|
*/
|
|
stride += conf->raid_disks - 1;
|
|
sector_div(stride, conf->raid_disks);
|
|
|
|
conf->dev_sectors = stride << conf->chunk_shift;
|
|
|
|
if (fo)
|
|
stride = 1;
|
|
else
|
|
sector_div(stride, fc);
|
|
conf->stride = stride << conf->chunk_shift;
|
|
|
|
|
|
spin_lock_init(&conf->device_lock);
|
|
INIT_LIST_HEAD(&conf->retry_list);
|
|
|
|
spin_lock_init(&conf->resync_lock);
|
|
init_waitqueue_head(&conf->wait_barrier);
|
|
|
|
conf->thread = md_register_thread(raid10d, mddev, NULL);
|
|
if (!conf->thread)
|
|
goto out;
|
|
|
|
conf->mddev = mddev;
|
|
return conf;
|
|
|
|
out:
|
|
printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
|
|
mdname(mddev));
|
|
if (conf) {
|
|
if (conf->r10bio_pool)
|
|
mempool_destroy(conf->r10bio_pool);
|
|
kfree(conf->mirrors);
|
|
safe_put_page(conf->tmppage);
|
|
kfree(conf);
|
|
}
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static int run(struct mddev *mddev)
|
|
{
|
|
struct r10conf *conf;
|
|
int i, disk_idx, chunk_size;
|
|
struct mirror_info *disk;
|
|
struct md_rdev *rdev;
|
|
sector_t size;
|
|
|
|
/*
|
|
* copy the already verified devices into our private RAID10
|
|
* bookkeeping area. [whatever we allocate in run(),
|
|
* should be freed in stop()]
|
|
*/
|
|
|
|
if (mddev->private == NULL) {
|
|
conf = setup_conf(mddev);
|
|
if (IS_ERR(conf))
|
|
return PTR_ERR(conf);
|
|
mddev->private = conf;
|
|
}
|
|
conf = mddev->private;
|
|
if (!conf)
|
|
goto out;
|
|
|
|
mddev->thread = conf->thread;
|
|
conf->thread = NULL;
|
|
|
|
chunk_size = mddev->chunk_sectors << 9;
|
|
blk_queue_io_min(mddev->queue, chunk_size);
|
|
if (conf->raid_disks % conf->near_copies)
|
|
blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
|
|
else
|
|
blk_queue_io_opt(mddev->queue, chunk_size *
|
|
(conf->raid_disks / conf->near_copies));
|
|
|
|
list_for_each_entry(rdev, &mddev->disks, same_set) {
|
|
|
|
disk_idx = rdev->raid_disk;
|
|
if (disk_idx >= conf->raid_disks
|
|
|| disk_idx < 0)
|
|
continue;
|
|
disk = conf->mirrors + disk_idx;
|
|
|
|
if (test_bit(Replacement, &rdev->flags)) {
|
|
if (disk->replacement)
|
|
goto out_free_conf;
|
|
disk->replacement = rdev;
|
|
} else {
|
|
if (disk->rdev)
|
|
goto out_free_conf;
|
|
disk->rdev = rdev;
|
|
}
|
|
|
|
disk->rdev = rdev;
|
|
disk_stack_limits(mddev->gendisk, rdev->bdev,
|
|
rdev->data_offset << 9);
|
|
/* as we don't honour merge_bvec_fn, we must never risk
|
|
* violating it, so limit max_segments to 1 lying
|
|
* within a single page.
|
|
*/
|
|
if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
|
|
blk_queue_max_segments(mddev->queue, 1);
|
|
blk_queue_segment_boundary(mddev->queue,
|
|
PAGE_CACHE_SIZE - 1);
|
|
}
|
|
|
|
disk->head_position = 0;
|
|
}
|
|
/* need to check that every block has at least one working mirror */
|
|
if (!enough(conf, -1)) {
|
|
printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
|
|
mdname(mddev));
|
|
goto out_free_conf;
|
|
}
|
|
|
|
mddev->degraded = 0;
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
|
|
disk = conf->mirrors + i;
|
|
|
|
if (!disk->rdev && disk->replacement) {
|
|
/* The replacement is all we have - use it */
|
|
disk->rdev = disk->replacement;
|
|
disk->replacement = NULL;
|
|
clear_bit(Replacement, &disk->rdev->flags);
|
|
}
|
|
|
|
if (!disk->rdev ||
|
|
!test_bit(In_sync, &disk->rdev->flags)) {
|
|
disk->head_position = 0;
|
|
mddev->degraded++;
|
|
if (disk->rdev)
|
|
conf->fullsync = 1;
|
|
}
|
|
disk->recovery_disabled = mddev->recovery_disabled - 1;
|
|
}
|
|
|
|
if (mddev->recovery_cp != MaxSector)
|
|
printk(KERN_NOTICE "md/raid10:%s: not clean"
|
|
" -- starting background reconstruction\n",
|
|
mdname(mddev));
|
|
printk(KERN_INFO
|
|
"md/raid10:%s: active with %d out of %d devices\n",
|
|
mdname(mddev), conf->raid_disks - mddev->degraded,
|
|
conf->raid_disks);
|
|
/*
|
|
* Ok, everything is just fine now
|
|
*/
|
|
mddev->dev_sectors = conf->dev_sectors;
|
|
size = raid10_size(mddev, 0, 0);
|
|
md_set_array_sectors(mddev, size);
|
|
mddev->resync_max_sectors = size;
|
|
|
|
mddev->queue->backing_dev_info.congested_fn = raid10_congested;
|
|
mddev->queue->backing_dev_info.congested_data = mddev;
|
|
|
|
/* Calculate max read-ahead size.
|
|
* We need to readahead at least twice a whole stripe....
|
|
* maybe...
|
|
*/
|
|
{
|
|
int stripe = conf->raid_disks *
|
|
((mddev->chunk_sectors << 9) / PAGE_SIZE);
|
|
stripe /= conf->near_copies;
|
|
if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
|
|
mddev->queue->backing_dev_info.ra_pages = 2* stripe;
|
|
}
|
|
|
|
if (conf->near_copies < conf->raid_disks)
|
|
blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
|
|
|
|
if (md_integrity_register(mddev))
|
|
goto out_free_conf;
|
|
|
|
return 0;
|
|
|
|
out_free_conf:
|
|
md_unregister_thread(&mddev->thread);
|
|
if (conf->r10bio_pool)
|
|
mempool_destroy(conf->r10bio_pool);
|
|
safe_put_page(conf->tmppage);
|
|
kfree(conf->mirrors);
|
|
kfree(conf);
|
|
mddev->private = NULL;
|
|
out:
|
|
return -EIO;
|
|
}
|
|
|
|
static int stop(struct mddev *mddev)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
|
|
raise_barrier(conf, 0);
|
|
lower_barrier(conf);
|
|
|
|
md_unregister_thread(&mddev->thread);
|
|
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
|
|
if (conf->r10bio_pool)
|
|
mempool_destroy(conf->r10bio_pool);
|
|
kfree(conf->mirrors);
|
|
kfree(conf);
|
|
mddev->private = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static void raid10_quiesce(struct mddev *mddev, int state)
|
|
{
|
|
struct r10conf *conf = mddev->private;
|
|
|
|
switch(state) {
|
|
case 1:
|
|
raise_barrier(conf, 0);
|
|
break;
|
|
case 0:
|
|
lower_barrier(conf);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void *raid10_takeover_raid0(struct mddev *mddev)
|
|
{
|
|
struct md_rdev *rdev;
|
|
struct r10conf *conf;
|
|
|
|
if (mddev->degraded > 0) {
|
|
printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
|
|
mdname(mddev));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
/* Set new parameters */
|
|
mddev->new_level = 10;
|
|
/* new layout: far_copies = 1, near_copies = 2 */
|
|
mddev->new_layout = (1<<8) + 2;
|
|
mddev->new_chunk_sectors = mddev->chunk_sectors;
|
|
mddev->delta_disks = mddev->raid_disks;
|
|
mddev->raid_disks *= 2;
|
|
/* make sure it will be not marked as dirty */
|
|
mddev->recovery_cp = MaxSector;
|
|
|
|
conf = setup_conf(mddev);
|
|
if (!IS_ERR(conf)) {
|
|
list_for_each_entry(rdev, &mddev->disks, same_set)
|
|
if (rdev->raid_disk >= 0)
|
|
rdev->new_raid_disk = rdev->raid_disk * 2;
|
|
conf->barrier = 1;
|
|
}
|
|
|
|
return conf;
|
|
}
|
|
|
|
static void *raid10_takeover(struct mddev *mddev)
|
|
{
|
|
struct r0conf *raid0_conf;
|
|
|
|
/* raid10 can take over:
|
|
* raid0 - providing it has only two drives
|
|
*/
|
|
if (mddev->level == 0) {
|
|
/* for raid0 takeover only one zone is supported */
|
|
raid0_conf = mddev->private;
|
|
if (raid0_conf->nr_strip_zones > 1) {
|
|
printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
|
|
" with more than one zone.\n",
|
|
mdname(mddev));
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
return raid10_takeover_raid0(mddev);
|
|
}
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
static struct md_personality raid10_personality =
|
|
{
|
|
.name = "raid10",
|
|
.level = 10,
|
|
.owner = THIS_MODULE,
|
|
.make_request = make_request,
|
|
.run = run,
|
|
.stop = stop,
|
|
.status = status,
|
|
.error_handler = error,
|
|
.hot_add_disk = raid10_add_disk,
|
|
.hot_remove_disk= raid10_remove_disk,
|
|
.spare_active = raid10_spare_active,
|
|
.sync_request = sync_request,
|
|
.quiesce = raid10_quiesce,
|
|
.size = raid10_size,
|
|
.takeover = raid10_takeover,
|
|
};
|
|
|
|
static int __init raid_init(void)
|
|
{
|
|
return register_md_personality(&raid10_personality);
|
|
}
|
|
|
|
static void raid_exit(void)
|
|
{
|
|
unregister_md_personality(&raid10_personality);
|
|
}
|
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module_init(raid_init);
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module_exit(raid_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
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MODULE_ALIAS("md-personality-9"); /* RAID10 */
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MODULE_ALIAS("md-raid10");
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MODULE_ALIAS("md-level-10");
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module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
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