v4.19.13 snapshot.
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
new file mode 100644
index 0000000..3a7c363
--- /dev/null
+++ b/drivers/md/raid5-ppl.c
@@ -0,0 +1,1505 @@
+/*
+ * Partial Parity Log for closing the RAID5 write hole
+ * Copyright (c) 2017, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/crc32c.h>
+#include <linux/flex_array.h>
+#include <linux/async_tx.h>
+#include <linux/raid/md_p.h>
+#include "md.h"
+#include "raid5.h"
+
+/*
+ * PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
+ * partial parity data. The header contains an array of entries
+ * (struct ppl_header_entry) which describe the logged write requests.
+ * Partial parity for the entries comes after the header, written in the same
+ * sequence as the entries:
+ *
+ * Header
+ * entry0
+ * ...
+ * entryN
+ * PP data
+ * PP for entry0
+ * ...
+ * PP for entryN
+ *
+ * An entry describes one or more consecutive stripe_heads, up to a full
+ * stripe. The modifed raid data chunks form an m-by-n matrix, where m is the
+ * number of stripe_heads in the entry and n is the number of modified data
+ * disks. Every stripe_head in the entry must write to the same data disks.
+ * An example of a valid case described by a single entry (writes to the first
+ * stripe of a 4 disk array, 16k chunk size):
+ *
+ * sh->sector dd0 dd1 dd2 ppl
+ * +-----+-----+-----+
+ * 0 | --- | --- | --- | +----+
+ * 8 | -W- | -W- | --- | | pp | data_sector = 8
+ * 16 | -W- | -W- | --- | | pp | data_size = 3 * 2 * 4k
+ * 24 | -W- | -W- | --- | | pp | pp_size = 3 * 4k
+ * +-----+-----+-----+ +----+
+ *
+ * data_sector is the first raid sector of the modified data, data_size is the
+ * total size of modified data and pp_size is the size of partial parity for
+ * this entry. Entries for full stripe writes contain no partial parity
+ * (pp_size = 0), they only mark the stripes for which parity should be
+ * recalculated after an unclean shutdown. Every entry holds a checksum of its
+ * partial parity, the header also has a checksum of the header itself.
+ *
+ * A write request is always logged to the PPL instance stored on the parity
+ * disk of the corresponding stripe. For each member disk there is one ppl_log
+ * used to handle logging for this disk, independently from others. They are
+ * grouped in child_logs array in struct ppl_conf, which is assigned to
+ * r5conf->log_private.
+ *
+ * ppl_io_unit represents a full PPL write, header_page contains the ppl_header.
+ * PPL entries for logged stripes are added in ppl_log_stripe(). A stripe_head
+ * can be appended to the last entry if it meets the conditions for a valid
+ * entry described above, otherwise a new entry is added. Checksums of entries
+ * are calculated incrementally as stripes containing partial parity are being
+ * added. ppl_submit_iounit() calculates the checksum of the header and submits
+ * a bio containing the header page and partial parity pages (sh->ppl_page) for
+ * all stripes of the io_unit. When the PPL write completes, the stripes
+ * associated with the io_unit are released and raid5d starts writing their data
+ * and parity. When all stripes are written, the io_unit is freed and the next
+ * can be submitted.
+ *
+ * An io_unit is used to gather stripes until it is submitted or becomes full
+ * (if the maximum number of entries or size of PPL is reached). Another io_unit
+ * can't be submitted until the previous has completed (PPL and stripe
+ * data+parity is written). The log->io_list tracks all io_units of a log
+ * (for a single member disk). New io_units are added to the end of the list
+ * and the first io_unit is submitted, if it is not submitted already.
+ * The current io_unit accepting new stripes is always at the end of the list.
+ *
+ * If write-back cache is enabled for any of the disks in the array, its data
+ * must be flushed before next io_unit is submitted.
+ */
+
+#define PPL_SPACE_SIZE (128 * 1024)
+
+struct ppl_conf {
+ struct mddev *mddev;
+
+ /* array of child logs, one for each raid disk */
+ struct ppl_log *child_logs;
+ int count;
+
+ int block_size; /* the logical block size used for data_sector
+ * in ppl_header_entry */
+ u32 signature; /* raid array identifier */
+ atomic64_t seq; /* current log write sequence number */
+
+ struct kmem_cache *io_kc;
+ mempool_t io_pool;
+ struct bio_set bs;
+ struct bio_set flush_bs;
+
+ /* used only for recovery */
+ int recovered_entries;
+ int mismatch_count;
+
+ /* stripes to retry if failed to allocate io_unit */
+ struct list_head no_mem_stripes;
+ spinlock_t no_mem_stripes_lock;
+};
+
+struct ppl_log {
+ struct ppl_conf *ppl_conf; /* shared between all log instances */
+
+ struct md_rdev *rdev; /* array member disk associated with
+ * this log instance */
+ struct mutex io_mutex;
+ struct ppl_io_unit *current_io; /* current io_unit accepting new data
+ * always at the end of io_list */
+ spinlock_t io_list_lock;
+ struct list_head io_list; /* all io_units of this log */
+
+ sector_t next_io_sector;
+ unsigned int entry_space;
+ bool use_multippl;
+ bool wb_cache_on;
+ unsigned long disk_flush_bitmap;
+};
+
+#define PPL_IO_INLINE_BVECS 32
+
+struct ppl_io_unit {
+ struct ppl_log *log;
+
+ struct page *header_page; /* for ppl_header */
+
+ unsigned int entries_count; /* number of entries in ppl_header */
+ unsigned int pp_size; /* total size current of partial parity */
+
+ u64 seq; /* sequence number of this log write */
+ struct list_head log_sibling; /* log->io_list */
+
+ struct list_head stripe_list; /* stripes added to the io_unit */
+ atomic_t pending_stripes; /* how many stripes not written to raid */
+ atomic_t pending_flushes; /* how many disk flushes are in progress */
+
+ bool submitted; /* true if write to log started */
+
+ /* inline bio and its biovec for submitting the iounit */
+ struct bio bio;
+ struct bio_vec biovec[PPL_IO_INLINE_BVECS];
+};
+
+struct dma_async_tx_descriptor *
+ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
+ struct dma_async_tx_descriptor *tx)
+{
+ int disks = sh->disks;
+ struct page **srcs = flex_array_get(percpu->scribble, 0);
+ int count = 0, pd_idx = sh->pd_idx, i;
+ struct async_submit_ctl submit;
+
+ pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
+
+ /*
+ * Partial parity is the XOR of stripe data chunks that are not changed
+ * during the write request. Depending on available data
+ * (read-modify-write vs. reconstruct-write case) we calculate it
+ * differently.
+ */
+ if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
+ /*
+ * rmw: xor old data and parity from updated disks
+ * This is calculated earlier by ops_run_prexor5() so just copy
+ * the parity dev page.
+ */
+ srcs[count++] = sh->dev[pd_idx].page;
+ } else if (sh->reconstruct_state == reconstruct_state_drain_run) {
+ /* rcw: xor data from all not updated disks */
+ for (i = disks; i--;) {
+ struct r5dev *dev = &sh->dev[i];
+ if (test_bit(R5_UPTODATE, &dev->flags))
+ srcs[count++] = dev->page;
+ }
+ } else {
+ return tx;
+ }
+
+ init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, tx,
+ NULL, sh, flex_array_get(percpu->scribble, 0)
+ + sizeof(struct page *) * (sh->disks + 2));
+
+ if (count == 1)
+ tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,
+ &submit);
+ else
+ tx = async_xor(sh->ppl_page, srcs, 0, count, PAGE_SIZE,
+ &submit);
+
+ return tx;
+}
+
+static void *ppl_io_pool_alloc(gfp_t gfp_mask, void *pool_data)
+{
+ struct kmem_cache *kc = pool_data;
+ struct ppl_io_unit *io;
+
+ io = kmem_cache_alloc(kc, gfp_mask);
+ if (!io)
+ return NULL;
+
+ io->header_page = alloc_page(gfp_mask);
+ if (!io->header_page) {
+ kmem_cache_free(kc, io);
+ return NULL;
+ }
+
+ return io;
+}
+
+static void ppl_io_pool_free(void *element, void *pool_data)
+{
+ struct kmem_cache *kc = pool_data;
+ struct ppl_io_unit *io = element;
+
+ __free_page(io->header_page);
+ kmem_cache_free(kc, io);
+}
+
+static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
+ struct stripe_head *sh)
+{
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct ppl_io_unit *io;
+ struct ppl_header *pplhdr;
+ struct page *header_page;
+
+ io = mempool_alloc(&ppl_conf->io_pool, GFP_NOWAIT);
+ if (!io)
+ return NULL;
+
+ header_page = io->header_page;
+ memset(io, 0, sizeof(*io));
+ io->header_page = header_page;
+
+ io->log = log;
+ INIT_LIST_HEAD(&io->log_sibling);
+ INIT_LIST_HEAD(&io->stripe_list);
+ atomic_set(&io->pending_stripes, 0);
+ atomic_set(&io->pending_flushes, 0);
+ bio_init(&io->bio, io->biovec, PPL_IO_INLINE_BVECS);
+
+ pplhdr = page_address(io->header_page);
+ clear_page(pplhdr);
+ memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
+ pplhdr->signature = cpu_to_le32(ppl_conf->signature);
+
+ io->seq = atomic64_add_return(1, &ppl_conf->seq);
+ pplhdr->generation = cpu_to_le64(io->seq);
+
+ return io;
+}
+
+static int ppl_log_stripe(struct ppl_log *log, struct stripe_head *sh)
+{
+ struct ppl_io_unit *io = log->current_io;
+ struct ppl_header_entry *e = NULL;
+ struct ppl_header *pplhdr;
+ int i;
+ sector_t data_sector = 0;
+ int data_disks = 0;
+ struct r5conf *conf = sh->raid_conf;
+
+ pr_debug("%s: stripe: %llu\n", __func__, (unsigned long long)sh->sector);
+
+ /* check if current io_unit is full */
+ if (io && (io->pp_size == log->entry_space ||
+ io->entries_count == PPL_HDR_MAX_ENTRIES)) {
+ pr_debug("%s: add io_unit blocked by seq: %llu\n",
+ __func__, io->seq);
+ io = NULL;
+ }
+
+ /* add a new unit if there is none or the current is full */
+ if (!io) {
+ io = ppl_new_iounit(log, sh);
+ if (!io)
+ return -ENOMEM;
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&io->log_sibling, &log->io_list);
+ spin_unlock_irq(&log->io_list_lock);
+
+ log->current_io = io;
+ }
+
+ for (i = 0; i < sh->disks; i++) {
+ struct r5dev *dev = &sh->dev[i];
+
+ if (i != sh->pd_idx && test_bit(R5_Wantwrite, &dev->flags)) {
+ if (!data_disks || dev->sector < data_sector)
+ data_sector = dev->sector;
+ data_disks++;
+ }
+ }
+ BUG_ON(!data_disks);
+
+ pr_debug("%s: seq: %llu data_sector: %llu data_disks: %d\n", __func__,
+ io->seq, (unsigned long long)data_sector, data_disks);
+
+ pplhdr = page_address(io->header_page);
+
+ if (io->entries_count > 0) {
+ struct ppl_header_entry *last =
+ &pplhdr->entries[io->entries_count - 1];
+ struct stripe_head *sh_last = list_last_entry(
+ &io->stripe_list, struct stripe_head, log_list);
+ u64 data_sector_last = le64_to_cpu(last->data_sector);
+ u32 data_size_last = le32_to_cpu(last->data_size);
+
+ /*
+ * Check if we can append the stripe to the last entry. It must
+ * be just after the last logged stripe and write to the same
+ * disks. Use bit shift and logarithm to avoid 64-bit division.
+ */
+ if ((sh->sector == sh_last->sector + STRIPE_SECTORS) &&
+ (data_sector >> ilog2(conf->chunk_sectors) ==
+ data_sector_last >> ilog2(conf->chunk_sectors)) &&
+ ((data_sector - data_sector_last) * data_disks ==
+ data_size_last >> 9))
+ e = last;
+ }
+
+ if (!e) {
+ e = &pplhdr->entries[io->entries_count++];
+ e->data_sector = cpu_to_le64(data_sector);
+ e->parity_disk = cpu_to_le32(sh->pd_idx);
+ e->checksum = cpu_to_le32(~0);
+ }
+
+ le32_add_cpu(&e->data_size, data_disks << PAGE_SHIFT);
+
+ /* don't write any PP if full stripe write */
+ if (!test_bit(STRIPE_FULL_WRITE, &sh->state)) {
+ le32_add_cpu(&e->pp_size, PAGE_SIZE);
+ io->pp_size += PAGE_SIZE;
+ e->checksum = cpu_to_le32(crc32c_le(le32_to_cpu(e->checksum),
+ page_address(sh->ppl_page),
+ PAGE_SIZE));
+ }
+
+ list_add_tail(&sh->log_list, &io->stripe_list);
+ atomic_inc(&io->pending_stripes);
+ sh->ppl_io = io;
+
+ return 0;
+}
+
+int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh)
+{
+ struct ppl_conf *ppl_conf = conf->log_private;
+ struct ppl_io_unit *io = sh->ppl_io;
+ struct ppl_log *log;
+
+ if (io || test_bit(STRIPE_SYNCING, &sh->state) || !sh->ppl_page ||
+ !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
+ !test_bit(R5_Insync, &sh->dev[sh->pd_idx].flags)) {
+ clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
+ return -EAGAIN;
+ }
+
+ log = &ppl_conf->child_logs[sh->pd_idx];
+
+ mutex_lock(&log->io_mutex);
+
+ if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
+ mutex_unlock(&log->io_mutex);
+ return -EAGAIN;
+ }
+
+ set_bit(STRIPE_LOG_TRAPPED, &sh->state);
+ clear_bit(STRIPE_DELAYED, &sh->state);
+ atomic_inc(&sh->count);
+
+ if (ppl_log_stripe(log, sh)) {
+ spin_lock_irq(&ppl_conf->no_mem_stripes_lock);
+ list_add_tail(&sh->log_list, &ppl_conf->no_mem_stripes);
+ spin_unlock_irq(&ppl_conf->no_mem_stripes_lock);
+ }
+
+ mutex_unlock(&log->io_mutex);
+
+ return 0;
+}
+
+static void ppl_log_endio(struct bio *bio)
+{
+ struct ppl_io_unit *io = bio->bi_private;
+ struct ppl_log *log = io->log;
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct stripe_head *sh, *next;
+
+ pr_debug("%s: seq: %llu\n", __func__, io->seq);
+
+ if (bio->bi_status)
+ md_error(ppl_conf->mddev, log->rdev);
+
+ list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
+ list_del_init(&sh->log_list);
+
+ set_bit(STRIPE_HANDLE, &sh->state);
+ raid5_release_stripe(sh);
+ }
+}
+
+static void ppl_submit_iounit_bio(struct ppl_io_unit *io, struct bio *bio)
+{
+ char b[BDEVNAME_SIZE];
+
+ pr_debug("%s: seq: %llu size: %u sector: %llu dev: %s\n",
+ __func__, io->seq, bio->bi_iter.bi_size,
+ (unsigned long long)bio->bi_iter.bi_sector,
+ bio_devname(bio, b));
+
+ submit_bio(bio);
+}
+
+static void ppl_submit_iounit(struct ppl_io_unit *io)
+{
+ struct ppl_log *log = io->log;
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct ppl_header *pplhdr = page_address(io->header_page);
+ struct bio *bio = &io->bio;
+ struct stripe_head *sh;
+ int i;
+
+ bio->bi_private = io;
+
+ if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
+ ppl_log_endio(bio);
+ return;
+ }
+
+ for (i = 0; i < io->entries_count; i++) {
+ struct ppl_header_entry *e = &pplhdr->entries[i];
+
+ pr_debug("%s: seq: %llu entry: %d data_sector: %llu pp_size: %u data_size: %u\n",
+ __func__, io->seq, i, le64_to_cpu(e->data_sector),
+ le32_to_cpu(e->pp_size), le32_to_cpu(e->data_size));
+
+ e->data_sector = cpu_to_le64(le64_to_cpu(e->data_sector) >>
+ ilog2(ppl_conf->block_size >> 9));
+ e->checksum = cpu_to_le32(~le32_to_cpu(e->checksum));
+ }
+
+ pplhdr->entries_count = cpu_to_le32(io->entries_count);
+ pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PPL_HEADER_SIZE));
+
+ /* Rewind the buffer if current PPL is larger then remaining space */
+ if (log->use_multippl &&
+ log->rdev->ppl.sector + log->rdev->ppl.size - log->next_io_sector <
+ (PPL_HEADER_SIZE + io->pp_size) >> 9)
+ log->next_io_sector = log->rdev->ppl.sector;
+
+
+ bio->bi_end_io = ppl_log_endio;
+ bio->bi_opf = REQ_OP_WRITE | REQ_FUA;
+ bio_set_dev(bio, log->rdev->bdev);
+ bio->bi_iter.bi_sector = log->next_io_sector;
+ bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
+
+ pr_debug("%s: log->current_io_sector: %llu\n", __func__,
+ (unsigned long long)log->next_io_sector);
+
+ if (log->use_multippl)
+ log->next_io_sector += (PPL_HEADER_SIZE + io->pp_size) >> 9;
+
+ WARN_ON(log->disk_flush_bitmap != 0);
+
+ list_for_each_entry(sh, &io->stripe_list, log_list) {
+ for (i = 0; i < sh->disks; i++) {
+ struct r5dev *dev = &sh->dev[i];
+
+ if ((ppl_conf->child_logs[i].wb_cache_on) &&
+ (test_bit(R5_Wantwrite, &dev->flags))) {
+ set_bit(i, &log->disk_flush_bitmap);
+ }
+ }
+
+ /* entries for full stripe writes have no partial parity */
+ if (test_bit(STRIPE_FULL_WRITE, &sh->state))
+ continue;
+
+ if (!bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0)) {
+ struct bio *prev = bio;
+
+ bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES,
+ &ppl_conf->bs);
+ bio->bi_opf = prev->bi_opf;
+ bio_copy_dev(bio, prev);
+ bio->bi_iter.bi_sector = bio_end_sector(prev);
+ bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
+
+ bio_chain(bio, prev);
+ ppl_submit_iounit_bio(io, prev);
+ }
+ }
+
+ ppl_submit_iounit_bio(io, bio);
+}
+
+static void ppl_submit_current_io(struct ppl_log *log)
+{
+ struct ppl_io_unit *io;
+
+ spin_lock_irq(&log->io_list_lock);
+
+ io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
+ log_sibling);
+ if (io && io->submitted)
+ io = NULL;
+
+ spin_unlock_irq(&log->io_list_lock);
+
+ if (io) {
+ io->submitted = true;
+
+ if (io == log->current_io)
+ log->current_io = NULL;
+
+ ppl_submit_iounit(io);
+ }
+}
+
+void ppl_write_stripe_run(struct r5conf *conf)
+{
+ struct ppl_conf *ppl_conf = conf->log_private;
+ struct ppl_log *log;
+ int i;
+
+ for (i = 0; i < ppl_conf->count; i++) {
+ log = &ppl_conf->child_logs[i];
+
+ mutex_lock(&log->io_mutex);
+ ppl_submit_current_io(log);
+ mutex_unlock(&log->io_mutex);
+ }
+}
+
+static void ppl_io_unit_finished(struct ppl_io_unit *io)
+{
+ struct ppl_log *log = io->log;
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct r5conf *conf = ppl_conf->mddev->private;
+ unsigned long flags;
+
+ pr_debug("%s: seq: %llu\n", __func__, io->seq);
+
+ local_irq_save(flags);
+
+ spin_lock(&log->io_list_lock);
+ list_del(&io->log_sibling);
+ spin_unlock(&log->io_list_lock);
+
+ mempool_free(io, &ppl_conf->io_pool);
+
+ spin_lock(&ppl_conf->no_mem_stripes_lock);
+ if (!list_empty(&ppl_conf->no_mem_stripes)) {
+ struct stripe_head *sh;
+
+ sh = list_first_entry(&ppl_conf->no_mem_stripes,
+ struct stripe_head, log_list);
+ list_del_init(&sh->log_list);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ raid5_release_stripe(sh);
+ }
+ spin_unlock(&ppl_conf->no_mem_stripes_lock);
+
+ local_irq_restore(flags);
+
+ wake_up(&conf->wait_for_quiescent);
+}
+
+static void ppl_flush_endio(struct bio *bio)
+{
+ struct ppl_io_unit *io = bio->bi_private;
+ struct ppl_log *log = io->log;
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct r5conf *conf = ppl_conf->mddev->private;
+ char b[BDEVNAME_SIZE];
+
+ pr_debug("%s: dev: %s\n", __func__, bio_devname(bio, b));
+
+ if (bio->bi_status) {
+ struct md_rdev *rdev;
+
+ rcu_read_lock();
+ rdev = md_find_rdev_rcu(conf->mddev, bio_dev(bio));
+ if (rdev)
+ md_error(rdev->mddev, rdev);
+ rcu_read_unlock();
+ }
+
+ bio_put(bio);
+
+ if (atomic_dec_and_test(&io->pending_flushes)) {
+ ppl_io_unit_finished(io);
+ md_wakeup_thread(conf->mddev->thread);
+ }
+}
+
+static void ppl_do_flush(struct ppl_io_unit *io)
+{
+ struct ppl_log *log = io->log;
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct r5conf *conf = ppl_conf->mddev->private;
+ int raid_disks = conf->raid_disks;
+ int flushed_disks = 0;
+ int i;
+
+ atomic_set(&io->pending_flushes, raid_disks);
+
+ for_each_set_bit(i, &log->disk_flush_bitmap, raid_disks) {
+ struct md_rdev *rdev;
+ struct block_device *bdev = NULL;
+
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->disks[i].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags))
+ bdev = rdev->bdev;
+ rcu_read_unlock();
+
+ if (bdev) {
+ struct bio *bio;
+ char b[BDEVNAME_SIZE];
+
+ bio = bio_alloc_bioset(GFP_NOIO, 0, &ppl_conf->flush_bs);
+ bio_set_dev(bio, bdev);
+ bio->bi_private = io;
+ bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+ bio->bi_end_io = ppl_flush_endio;
+
+ pr_debug("%s: dev: %s\n", __func__,
+ bio_devname(bio, b));
+
+ submit_bio(bio);
+ flushed_disks++;
+ }
+ }
+
+ log->disk_flush_bitmap = 0;
+
+ for (i = flushed_disks ; i < raid_disks; i++) {
+ if (atomic_dec_and_test(&io->pending_flushes))
+ ppl_io_unit_finished(io);
+ }
+}
+
+static inline bool ppl_no_io_unit_submitted(struct r5conf *conf,
+ struct ppl_log *log)
+{
+ struct ppl_io_unit *io;
+
+ io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
+ log_sibling);
+
+ return !io || !io->submitted;
+}
+
+void ppl_quiesce(struct r5conf *conf, int quiesce)
+{
+ struct ppl_conf *ppl_conf = conf->log_private;
+ int i;
+
+ if (quiesce) {
+ for (i = 0; i < ppl_conf->count; i++) {
+ struct ppl_log *log = &ppl_conf->child_logs[i];
+
+ spin_lock_irq(&log->io_list_lock);
+ wait_event_lock_irq(conf->wait_for_quiescent,
+ ppl_no_io_unit_submitted(conf, log),
+ log->io_list_lock);
+ spin_unlock_irq(&log->io_list_lock);
+ }
+ }
+}
+
+int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio)
+{
+ if (bio->bi_iter.bi_size == 0) {
+ bio_endio(bio);
+ return 0;
+ }
+ bio->bi_opf &= ~REQ_PREFLUSH;
+ return -EAGAIN;
+}
+
+void ppl_stripe_write_finished(struct stripe_head *sh)
+{
+ struct ppl_io_unit *io;
+
+ io = sh->ppl_io;
+ sh->ppl_io = NULL;
+
+ if (io && atomic_dec_and_test(&io->pending_stripes)) {
+ if (io->log->disk_flush_bitmap)
+ ppl_do_flush(io);
+ else
+ ppl_io_unit_finished(io);
+ }
+}
+
+static void ppl_xor(int size, struct page *page1, struct page *page2)
+{
+ struct async_submit_ctl submit;
+ struct dma_async_tx_descriptor *tx;
+ struct page *xor_srcs[] = { page1, page2 };
+
+ init_async_submit(&submit, ASYNC_TX_ACK|ASYNC_TX_XOR_DROP_DST,
+ NULL, NULL, NULL, NULL);
+ tx = async_xor(page1, xor_srcs, 0, 2, size, &submit);
+
+ async_tx_quiesce(&tx);
+}
+
+/*
+ * PPL recovery strategy: xor partial parity and data from all modified data
+ * disks within a stripe and write the result as the new stripe parity. If all
+ * stripe data disks are modified (full stripe write), no partial parity is
+ * available, so just xor the data disks.
+ *
+ * Recovery of a PPL entry shall occur only if all modified data disks are
+ * available and read from all of them succeeds.
+ *
+ * A PPL entry applies to a stripe, partial parity size for an entry is at most
+ * the size of the chunk. Examples of possible cases for a single entry:
+ *
+ * case 0: single data disk write:
+ * data0 data1 data2 ppl parity
+ * +--------+--------+--------+ +--------------------+
+ * | ------ | ------ | ------ | +----+ | (no change) |
+ * | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
+ * | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
+ * | ------ | ------ | ------ | +----+ | (no change) |
+ * +--------+--------+--------+ +--------------------+
+ * pp_size = data_size
+ *
+ * case 1: more than one data disk write:
+ * data0 data1 data2 ppl parity
+ * +--------+--------+--------+ +--------------------+
+ * | ------ | ------ | ------ | +----+ | (no change) |
+ * | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
+ * | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
+ * | ------ | ------ | ------ | +----+ | (no change) |
+ * +--------+--------+--------+ +--------------------+
+ * pp_size = data_size / modified_data_disks
+ *
+ * case 2: write to all data disks (also full stripe write):
+ * data0 data1 data2 parity
+ * +--------+--------+--------+ +--------------------+
+ * | ------ | ------ | ------ | | (no change) |
+ * | -data- | -data- | -data- | --------> | xor all data |
+ * | ------ | ------ | ------ | --------> | (no change) |
+ * | ------ | ------ | ------ | | (no change) |
+ * +--------+--------+--------+ +--------------------+
+ * pp_size = 0
+ *
+ * The following cases are possible only in other implementations. The recovery
+ * code can handle them, but they are not generated at runtime because they can
+ * be reduced to cases 0, 1 and 2:
+ *
+ * case 3:
+ * data0 data1 data2 ppl parity
+ * +--------+--------+--------+ +----+ +--------------------+
+ * | ------ | -data- | -data- | | pp | | data1 ^ data2 ^ pp |
+ * | ------ | -data- | -data- | | pp | -> | data1 ^ data2 ^ pp |
+ * | -data- | -data- | -data- | | -- | -> | xor all data |
+ * | -data- | -data- | ------ | | pp | | data0 ^ data1 ^ pp |
+ * +--------+--------+--------+ +----+ +--------------------+
+ * pp_size = chunk_size
+ *
+ * case 4:
+ * data0 data1 data2 ppl parity
+ * +--------+--------+--------+ +----+ +--------------------+
+ * | ------ | -data- | ------ | | pp | | data1 ^ pp |
+ * | ------ | ------ | ------ | | -- | -> | (no change) |
+ * | ------ | ------ | ------ | | -- | -> | (no change) |
+ * | -data- | ------ | ------ | | pp | | data0 ^ pp |
+ * +--------+--------+--------+ +----+ +--------------------+
+ * pp_size = chunk_size
+ */
+static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
+ sector_t ppl_sector)
+{
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct mddev *mddev = ppl_conf->mddev;
+ struct r5conf *conf = mddev->private;
+ int block_size = ppl_conf->block_size;
+ struct page *page1;
+ struct page *page2;
+ sector_t r_sector_first;
+ sector_t r_sector_last;
+ int strip_sectors;
+ int data_disks;
+ int i;
+ int ret = 0;
+ char b[BDEVNAME_SIZE];
+ unsigned int pp_size = le32_to_cpu(e->pp_size);
+ unsigned int data_size = le32_to_cpu(e->data_size);
+
+ page1 = alloc_page(GFP_KERNEL);
+ page2 = alloc_page(GFP_KERNEL);
+
+ if (!page1 || !page2) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ r_sector_first = le64_to_cpu(e->data_sector) * (block_size >> 9);
+
+ if ((pp_size >> 9) < conf->chunk_sectors) {
+ if (pp_size > 0) {
+ data_disks = data_size / pp_size;
+ strip_sectors = pp_size >> 9;
+ } else {
+ data_disks = conf->raid_disks - conf->max_degraded;
+ strip_sectors = (data_size >> 9) / data_disks;
+ }
+ r_sector_last = r_sector_first +
+ (data_disks - 1) * conf->chunk_sectors +
+ strip_sectors;
+ } else {
+ data_disks = conf->raid_disks - conf->max_degraded;
+ strip_sectors = conf->chunk_sectors;
+ r_sector_last = r_sector_first + (data_size >> 9);
+ }
+
+ pr_debug("%s: array sector first: %llu last: %llu\n", __func__,
+ (unsigned long long)r_sector_first,
+ (unsigned long long)r_sector_last);
+
+ /* if start and end is 4k aligned, use a 4k block */
+ if (block_size == 512 &&
+ (r_sector_first & (STRIPE_SECTORS - 1)) == 0 &&
+ (r_sector_last & (STRIPE_SECTORS - 1)) == 0)
+ block_size = STRIPE_SIZE;
+
+ /* iterate through blocks in strip */
+ for (i = 0; i < strip_sectors; i += (block_size >> 9)) {
+ bool update_parity = false;
+ sector_t parity_sector;
+ struct md_rdev *parity_rdev;
+ struct stripe_head sh;
+ int disk;
+ int indent = 0;
+
+ pr_debug("%s:%*s iter %d start\n", __func__, indent, "", i);
+ indent += 2;
+
+ memset(page_address(page1), 0, PAGE_SIZE);
+
+ /* iterate through data member disks */
+ for (disk = 0; disk < data_disks; disk++) {
+ int dd_idx;
+ struct md_rdev *rdev;
+ sector_t sector;
+ sector_t r_sector = r_sector_first + i +
+ (disk * conf->chunk_sectors);
+
+ pr_debug("%s:%*s data member disk %d start\n",
+ __func__, indent, "", disk);
+ indent += 2;
+
+ if (r_sector >= r_sector_last) {
+ pr_debug("%s:%*s array sector %llu doesn't need parity update\n",
+ __func__, indent, "",
+ (unsigned long long)r_sector);
+ indent -= 2;
+ continue;
+ }
+
+ update_parity = true;
+
+ /* map raid sector to member disk */
+ sector = raid5_compute_sector(conf, r_sector, 0,
+ &dd_idx, NULL);
+ pr_debug("%s:%*s processing array sector %llu => data member disk %d, sector %llu\n",
+ __func__, indent, "",
+ (unsigned long long)r_sector, dd_idx,
+ (unsigned long long)sector);
+
+ rdev = conf->disks[dd_idx].rdev;
+ if (!rdev || (!test_bit(In_sync, &rdev->flags) &&
+ sector >= rdev->recovery_offset)) {
+ pr_debug("%s:%*s data member disk %d missing\n",
+ __func__, indent, "", dd_idx);
+ update_parity = false;
+ break;
+ }
+
+ pr_debug("%s:%*s reading data member disk %s sector %llu\n",
+ __func__, indent, "", bdevname(rdev->bdev, b),
+ (unsigned long long)sector);
+ if (!sync_page_io(rdev, sector, block_size, page2,
+ REQ_OP_READ, 0, false)) {
+ md_error(mddev, rdev);
+ pr_debug("%s:%*s read failed!\n", __func__,
+ indent, "");
+ ret = -EIO;
+ goto out;
+ }
+
+ ppl_xor(block_size, page1, page2);
+
+ indent -= 2;
+ }
+
+ if (!update_parity)
+ continue;
+
+ if (pp_size > 0) {
+ pr_debug("%s:%*s reading pp disk sector %llu\n",
+ __func__, indent, "",
+ (unsigned long long)(ppl_sector + i));
+ if (!sync_page_io(log->rdev,
+ ppl_sector - log->rdev->data_offset + i,
+ block_size, page2, REQ_OP_READ, 0,
+ false)) {
+ pr_debug("%s:%*s read failed!\n", __func__,
+ indent, "");
+ md_error(mddev, log->rdev);
+ ret = -EIO;
+ goto out;
+ }
+
+ ppl_xor(block_size, page1, page2);
+ }
+
+ /* map raid sector to parity disk */
+ parity_sector = raid5_compute_sector(conf, r_sector_first + i,
+ 0, &disk, &sh);
+ BUG_ON(sh.pd_idx != le32_to_cpu(e->parity_disk));
+ parity_rdev = conf->disks[sh.pd_idx].rdev;
+
+ BUG_ON(parity_rdev->bdev->bd_dev != log->rdev->bdev->bd_dev);
+ pr_debug("%s:%*s write parity at sector %llu, disk %s\n",
+ __func__, indent, "",
+ (unsigned long long)parity_sector,
+ bdevname(parity_rdev->bdev, b));
+ if (!sync_page_io(parity_rdev, parity_sector, block_size,
+ page1, REQ_OP_WRITE, 0, false)) {
+ pr_debug("%s:%*s parity write error!\n", __func__,
+ indent, "");
+ md_error(mddev, parity_rdev);
+ ret = -EIO;
+ goto out;
+ }
+ }
+out:
+ if (page1)
+ __free_page(page1);
+ if (page2)
+ __free_page(page2);
+ return ret;
+}
+
+static int ppl_recover(struct ppl_log *log, struct ppl_header *pplhdr,
+ sector_t offset)
+{
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct md_rdev *rdev = log->rdev;
+ struct mddev *mddev = rdev->mddev;
+ sector_t ppl_sector = rdev->ppl.sector + offset +
+ (PPL_HEADER_SIZE >> 9);
+ struct page *page;
+ int i;
+ int ret = 0;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ /* iterate through all PPL entries saved */
+ for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++) {
+ struct ppl_header_entry *e = &pplhdr->entries[i];
+ u32 pp_size = le32_to_cpu(e->pp_size);
+ sector_t sector = ppl_sector;
+ int ppl_entry_sectors = pp_size >> 9;
+ u32 crc, crc_stored;
+
+ pr_debug("%s: disk: %d entry: %d ppl_sector: %llu pp_size: %u\n",
+ __func__, rdev->raid_disk, i,
+ (unsigned long long)ppl_sector, pp_size);
+
+ crc = ~0;
+ crc_stored = le32_to_cpu(e->checksum);
+
+ /* read parial parity for this entry and calculate its checksum */
+ while (pp_size) {
+ int s = pp_size > PAGE_SIZE ? PAGE_SIZE : pp_size;
+
+ if (!sync_page_io(rdev, sector - rdev->data_offset,
+ s, page, REQ_OP_READ, 0, false)) {
+ md_error(mddev, rdev);
+ ret = -EIO;
+ goto out;
+ }
+
+ crc = crc32c_le(crc, page_address(page), s);
+
+ pp_size -= s;
+ sector += s >> 9;
+ }
+
+ crc = ~crc;
+
+ if (crc != crc_stored) {
+ /*
+ * Don't recover this entry if the checksum does not
+ * match, but keep going and try to recover other
+ * entries.
+ */
+ pr_debug("%s: ppl entry crc does not match: stored: 0x%x calculated: 0x%x\n",
+ __func__, crc_stored, crc);
+ ppl_conf->mismatch_count++;
+ } else {
+ ret = ppl_recover_entry(log, e, ppl_sector);
+ if (ret)
+ goto out;
+ ppl_conf->recovered_entries++;
+ }
+
+ ppl_sector += ppl_entry_sectors;
+ }
+
+ /* flush the disk cache after recovery if necessary */
+ ret = blkdev_issue_flush(rdev->bdev, GFP_KERNEL, NULL);
+out:
+ __free_page(page);
+ return ret;
+}
+
+static int ppl_write_empty_header(struct ppl_log *log)
+{
+ struct page *page;
+ struct ppl_header *pplhdr;
+ struct md_rdev *rdev = log->rdev;
+ int ret = 0;
+
+ pr_debug("%s: disk: %d ppl_sector: %llu\n", __func__,
+ rdev->raid_disk, (unsigned long long)rdev->ppl.sector);
+
+ page = alloc_page(GFP_NOIO | __GFP_ZERO);
+ if (!page)
+ return -ENOMEM;
+
+ pplhdr = page_address(page);
+ /* zero out PPL space to avoid collision with old PPLs */
+ blkdev_issue_zeroout(rdev->bdev, rdev->ppl.sector,
+ log->rdev->ppl.size, GFP_NOIO, 0);
+ memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
+ pplhdr->signature = cpu_to_le32(log->ppl_conf->signature);
+ pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PAGE_SIZE));
+
+ if (!sync_page_io(rdev, rdev->ppl.sector - rdev->data_offset,
+ PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_SYNC |
+ REQ_FUA, 0, false)) {
+ md_error(rdev->mddev, rdev);
+ ret = -EIO;
+ }
+
+ __free_page(page);
+ return ret;
+}
+
+static int ppl_load_distributed(struct ppl_log *log)
+{
+ struct ppl_conf *ppl_conf = log->ppl_conf;
+ struct md_rdev *rdev = log->rdev;
+ struct mddev *mddev = rdev->mddev;
+ struct page *page, *page2, *tmp;
+ struct ppl_header *pplhdr = NULL, *prev_pplhdr = NULL;
+ u32 crc, crc_stored;
+ u32 signature;
+ int ret = 0, i;
+ sector_t pplhdr_offset = 0, prev_pplhdr_offset = 0;
+
+ pr_debug("%s: disk: %d\n", __func__, rdev->raid_disk);
+ /* read PPL headers, find the recent one */
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ page2 = alloc_page(GFP_KERNEL);
+ if (!page2) {
+ __free_page(page);
+ return -ENOMEM;
+ }
+
+ /* searching ppl area for latest ppl */
+ while (pplhdr_offset < rdev->ppl.size - (PPL_HEADER_SIZE >> 9)) {
+ if (!sync_page_io(rdev,
+ rdev->ppl.sector - rdev->data_offset +
+ pplhdr_offset, PAGE_SIZE, page, REQ_OP_READ,
+ 0, false)) {
+ md_error(mddev, rdev);
+ ret = -EIO;
+ /* if not able to read - don't recover any PPL */
+ pplhdr = NULL;
+ break;
+ }
+ pplhdr = page_address(page);
+
+ /* check header validity */
+ crc_stored = le32_to_cpu(pplhdr->checksum);
+ pplhdr->checksum = 0;
+ crc = ~crc32c_le(~0, pplhdr, PAGE_SIZE);
+
+ if (crc_stored != crc) {
+ pr_debug("%s: ppl header crc does not match: stored: 0x%x calculated: 0x%x (offset: %llu)\n",
+ __func__, crc_stored, crc,
+ (unsigned long long)pplhdr_offset);
+ pplhdr = prev_pplhdr;
+ pplhdr_offset = prev_pplhdr_offset;
+ break;
+ }
+
+ signature = le32_to_cpu(pplhdr->signature);
+
+ if (mddev->external) {
+ /*
+ * For external metadata the header signature is set and
+ * validated in userspace.
+ */
+ ppl_conf->signature = signature;
+ } else if (ppl_conf->signature != signature) {
+ pr_debug("%s: ppl header signature does not match: stored: 0x%x configured: 0x%x (offset: %llu)\n",
+ __func__, signature, ppl_conf->signature,
+ (unsigned long long)pplhdr_offset);
+ pplhdr = prev_pplhdr;
+ pplhdr_offset = prev_pplhdr_offset;
+ break;
+ }
+
+ if (prev_pplhdr && le64_to_cpu(prev_pplhdr->generation) >
+ le64_to_cpu(pplhdr->generation)) {
+ /* previous was newest */
+ pplhdr = prev_pplhdr;
+ pplhdr_offset = prev_pplhdr_offset;
+ break;
+ }
+
+ prev_pplhdr_offset = pplhdr_offset;
+ prev_pplhdr = pplhdr;
+
+ tmp = page;
+ page = page2;
+ page2 = tmp;
+
+ /* calculate next potential ppl offset */
+ for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++)
+ pplhdr_offset +=
+ le32_to_cpu(pplhdr->entries[i].pp_size) >> 9;
+ pplhdr_offset += PPL_HEADER_SIZE >> 9;
+ }
+
+ /* no valid ppl found */
+ if (!pplhdr)
+ ppl_conf->mismatch_count++;
+ else
+ pr_debug("%s: latest PPL found at offset: %llu, with generation: %llu\n",
+ __func__, (unsigned long long)pplhdr_offset,
+ le64_to_cpu(pplhdr->generation));
+
+ /* attempt to recover from log if we are starting a dirty array */
+ if (pplhdr && !mddev->pers && mddev->recovery_cp != MaxSector)
+ ret = ppl_recover(log, pplhdr, pplhdr_offset);
+
+ /* write empty header if we are starting the array */
+ if (!ret && !mddev->pers)
+ ret = ppl_write_empty_header(log);
+
+ __free_page(page);
+ __free_page(page2);
+
+ pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
+ __func__, ret, ppl_conf->mismatch_count,
+ ppl_conf->recovered_entries);
+ return ret;
+}
+
+static int ppl_load(struct ppl_conf *ppl_conf)
+{
+ int ret = 0;
+ u32 signature = 0;
+ bool signature_set = false;
+ int i;
+
+ for (i = 0; i < ppl_conf->count; i++) {
+ struct ppl_log *log = &ppl_conf->child_logs[i];
+
+ /* skip missing drive */
+ if (!log->rdev)
+ continue;
+
+ ret = ppl_load_distributed(log);
+ if (ret)
+ break;
+
+ /*
+ * For external metadata we can't check if the signature is
+ * correct on a single drive, but we can check if it is the same
+ * on all drives.
+ */
+ if (ppl_conf->mddev->external) {
+ if (!signature_set) {
+ signature = ppl_conf->signature;
+ signature_set = true;
+ } else if (signature != ppl_conf->signature) {
+ pr_warn("md/raid:%s: PPL header signature does not match on all member drives\n",
+ mdname(ppl_conf->mddev));
+ ret = -EINVAL;
+ break;
+ }
+ }
+ }
+
+ pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
+ __func__, ret, ppl_conf->mismatch_count,
+ ppl_conf->recovered_entries);
+ return ret;
+}
+
+static void __ppl_exit_log(struct ppl_conf *ppl_conf)
+{
+ clear_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
+ clear_bit(MD_HAS_MULTIPLE_PPLS, &ppl_conf->mddev->flags);
+
+ kfree(ppl_conf->child_logs);
+
+ bioset_exit(&ppl_conf->bs);
+ bioset_exit(&ppl_conf->flush_bs);
+ mempool_exit(&ppl_conf->io_pool);
+ kmem_cache_destroy(ppl_conf->io_kc);
+
+ kfree(ppl_conf);
+}
+
+void ppl_exit_log(struct r5conf *conf)
+{
+ struct ppl_conf *ppl_conf = conf->log_private;
+
+ if (ppl_conf) {
+ __ppl_exit_log(ppl_conf);
+ conf->log_private = NULL;
+ }
+}
+
+static int ppl_validate_rdev(struct md_rdev *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ int ppl_data_sectors;
+ int ppl_size_new;
+
+ /*
+ * The configured PPL size must be enough to store
+ * the header and (at the very least) partial parity
+ * for one stripe. Round it down to ensure the data
+ * space is cleanly divisible by stripe size.
+ */
+ ppl_data_sectors = rdev->ppl.size - (PPL_HEADER_SIZE >> 9);
+
+ if (ppl_data_sectors > 0)
+ ppl_data_sectors = rounddown(ppl_data_sectors, STRIPE_SECTORS);
+
+ if (ppl_data_sectors <= 0) {
+ pr_warn("md/raid:%s: PPL space too small on %s\n",
+ mdname(rdev->mddev), bdevname(rdev->bdev, b));
+ return -ENOSPC;
+ }
+
+ ppl_size_new = ppl_data_sectors + (PPL_HEADER_SIZE >> 9);
+
+ if ((rdev->ppl.sector < rdev->data_offset &&
+ rdev->ppl.sector + ppl_size_new > rdev->data_offset) ||
+ (rdev->ppl.sector >= rdev->data_offset &&
+ rdev->data_offset + rdev->sectors > rdev->ppl.sector)) {
+ pr_warn("md/raid:%s: PPL space overlaps with data on %s\n",
+ mdname(rdev->mddev), bdevname(rdev->bdev, b));
+ return -EINVAL;
+ }
+
+ if (!rdev->mddev->external &&
+ ((rdev->ppl.offset > 0 && rdev->ppl.offset < (rdev->sb_size >> 9)) ||
+ (rdev->ppl.offset <= 0 && rdev->ppl.offset + ppl_size_new > 0))) {
+ pr_warn("md/raid:%s: PPL space overlaps with superblock on %s\n",
+ mdname(rdev->mddev), bdevname(rdev->bdev, b));
+ return -EINVAL;
+ }
+
+ rdev->ppl.size = ppl_size_new;
+
+ return 0;
+}
+
+static void ppl_init_child_log(struct ppl_log *log, struct md_rdev *rdev)
+{
+ struct request_queue *q;
+
+ if ((rdev->ppl.size << 9) >= (PPL_SPACE_SIZE +
+ PPL_HEADER_SIZE) * 2) {
+ log->use_multippl = true;
+ set_bit(MD_HAS_MULTIPLE_PPLS,
+ &log->ppl_conf->mddev->flags);
+ log->entry_space = PPL_SPACE_SIZE;
+ } else {
+ log->use_multippl = false;
+ log->entry_space = (log->rdev->ppl.size << 9) -
+ PPL_HEADER_SIZE;
+ }
+ log->next_io_sector = rdev->ppl.sector;
+
+ q = bdev_get_queue(rdev->bdev);
+ if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
+ log->wb_cache_on = true;
+}
+
+int ppl_init_log(struct r5conf *conf)
+{
+ struct ppl_conf *ppl_conf;
+ struct mddev *mddev = conf->mddev;
+ int ret = 0;
+ int max_disks;
+ int i;
+
+ pr_debug("md/raid:%s: enabling distributed Partial Parity Log\n",
+ mdname(conf->mddev));
+
+ if (PAGE_SIZE != 4096)
+ return -EINVAL;
+
+ if (mddev->level != 5) {
+ pr_warn("md/raid:%s PPL is not compatible with raid level %d\n",
+ mdname(mddev), mddev->level);
+ return -EINVAL;
+ }
+
+ if (mddev->bitmap_info.file || mddev->bitmap_info.offset) {
+ pr_warn("md/raid:%s PPL is not compatible with bitmap\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+
+ if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
+ pr_warn("md/raid:%s PPL is not compatible with journal\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+
+ max_disks = FIELD_SIZEOF(struct ppl_log, disk_flush_bitmap) *
+ BITS_PER_BYTE;
+ if (conf->raid_disks > max_disks) {
+ pr_warn("md/raid:%s PPL doesn't support over %d disks in the array\n",
+ mdname(mddev), max_disks);
+ return -EINVAL;
+ }
+
+ ppl_conf = kzalloc(sizeof(struct ppl_conf), GFP_KERNEL);
+ if (!ppl_conf)
+ return -ENOMEM;
+
+ ppl_conf->mddev = mddev;
+
+ ppl_conf->io_kc = KMEM_CACHE(ppl_io_unit, 0);
+ if (!ppl_conf->io_kc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ ret = mempool_init(&ppl_conf->io_pool, conf->raid_disks, ppl_io_pool_alloc,
+ ppl_io_pool_free, ppl_conf->io_kc);
+ if (ret)
+ goto err;
+
+ ret = bioset_init(&ppl_conf->bs, conf->raid_disks, 0, BIOSET_NEED_BVECS);
+ if (ret)
+ goto err;
+
+ ret = bioset_init(&ppl_conf->flush_bs, conf->raid_disks, 0, 0);
+ if (ret)
+ goto err;
+
+ ppl_conf->count = conf->raid_disks;
+ ppl_conf->child_logs = kcalloc(ppl_conf->count, sizeof(struct ppl_log),
+ GFP_KERNEL);
+ if (!ppl_conf->child_logs) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ atomic64_set(&ppl_conf->seq, 0);
+ INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
+ spin_lock_init(&ppl_conf->no_mem_stripes_lock);
+
+ if (!mddev->external) {
+ ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
+ ppl_conf->block_size = 512;
+ } else {
+ ppl_conf->block_size = queue_logical_block_size(mddev->queue);
+ }
+
+ for (i = 0; i < ppl_conf->count; i++) {
+ struct ppl_log *log = &ppl_conf->child_logs[i];
+ struct md_rdev *rdev = conf->disks[i].rdev;
+
+ mutex_init(&log->io_mutex);
+ spin_lock_init(&log->io_list_lock);
+ INIT_LIST_HEAD(&log->io_list);
+
+ log->ppl_conf = ppl_conf;
+ log->rdev = rdev;
+
+ if (rdev) {
+ ret = ppl_validate_rdev(rdev);
+ if (ret)
+ goto err;
+
+ ppl_init_child_log(log, rdev);
+ }
+ }
+
+ /* load and possibly recover the logs from the member disks */
+ ret = ppl_load(ppl_conf);
+
+ if (ret) {
+ goto err;
+ } else if (!mddev->pers && mddev->recovery_cp == 0 &&
+ ppl_conf->recovered_entries > 0 &&
+ ppl_conf->mismatch_count == 0) {
+ /*
+ * If we are starting a dirty array and the recovery succeeds
+ * without any issues, set the array as clean.
+ */
+ mddev->recovery_cp = MaxSector;
+ set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
+ } else if (mddev->pers && ppl_conf->mismatch_count > 0) {
+ /* no mismatch allowed when enabling PPL for a running array */
+ ret = -EINVAL;
+ goto err;
+ }
+
+ conf->log_private = ppl_conf;
+ set_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
+
+ return 0;
+err:
+ __ppl_exit_log(ppl_conf);
+ return ret;
+}
+
+int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
+{
+ struct ppl_conf *ppl_conf = conf->log_private;
+ struct ppl_log *log;
+ int ret = 0;
+ char b[BDEVNAME_SIZE];
+
+ if (!rdev)
+ return -EINVAL;
+
+ pr_debug("%s: disk: %d operation: %s dev: %s\n",
+ __func__, rdev->raid_disk, add ? "add" : "remove",
+ bdevname(rdev->bdev, b));
+
+ if (rdev->raid_disk < 0)
+ return 0;
+
+ if (rdev->raid_disk >= ppl_conf->count)
+ return -ENODEV;
+
+ log = &ppl_conf->child_logs[rdev->raid_disk];
+
+ mutex_lock(&log->io_mutex);
+ if (add) {
+ ret = ppl_validate_rdev(rdev);
+ if (!ret) {
+ log->rdev = rdev;
+ ret = ppl_write_empty_header(log);
+ ppl_init_child_log(log, rdev);
+ }
+ } else {
+ log->rdev = NULL;
+ }
+ mutex_unlock(&log->io_mutex);
+
+ return ret;
+}