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-rw-r--r--drivers/md/raid5.c536
1 files changed, 536 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e372e57687e..0b700247965 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -52,6 +52,7 @@
#include "raid6.h"
#include <linux/raid/bitmap.h>
+#include <linux/async_tx.h>
/*
* Stripe cache
@@ -341,6 +342,541 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector
return sh;
}
+static int
+raid5_end_read_request(struct bio *bi, unsigned int bytes_done, int error);
+static int
+raid5_end_write_request (struct bio *bi, unsigned int bytes_done, int error);
+
+static void ops_run_io(struct stripe_head *sh)
+{
+ raid5_conf_t *conf = sh->raid_conf;
+ int i, disks = sh->disks;
+
+ might_sleep();
+
+ for (i = disks; i--; ) {
+ int rw;
+ struct bio *bi;
+ mdk_rdev_t *rdev;
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
+ rw = WRITE;
+ else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ rw = READ;
+ else
+ continue;
+
+ bi = &sh->dev[i].req;
+
+ bi->bi_rw = rw;
+ if (rw == WRITE)
+ bi->bi_end_io = raid5_end_write_request;
+ else
+ bi->bi_end_io = raid5_end_read_request;
+
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->disks[i].rdev);
+ if (rdev && test_bit(Faulty, &rdev->flags))
+ rdev = NULL;
+ if (rdev)
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+
+ if (rdev) {
+ if (test_bit(STRIPE_SYNCING, &sh->state) ||
+ test_bit(STRIPE_EXPAND_SOURCE, &sh->state) ||
+ test_bit(STRIPE_EXPAND_READY, &sh->state))
+ md_sync_acct(rdev->bdev, STRIPE_SECTORS);
+
+ bi->bi_bdev = rdev->bdev;
+ pr_debug("%s: for %llu schedule op %ld on disc %d\n",
+ __FUNCTION__, (unsigned long long)sh->sector,
+ bi->bi_rw, i);
+ atomic_inc(&sh->count);
+ bi->bi_sector = sh->sector + rdev->data_offset;
+ bi->bi_flags = 1 << BIO_UPTODATE;
+ bi->bi_vcnt = 1;
+ bi->bi_max_vecs = 1;
+ bi->bi_idx = 0;
+ bi->bi_io_vec = &sh->dev[i].vec;
+ bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
+ bi->bi_io_vec[0].bv_offset = 0;
+ bi->bi_size = STRIPE_SIZE;
+ bi->bi_next = NULL;
+ if (rw == WRITE &&
+ test_bit(R5_ReWrite, &sh->dev[i].flags))
+ atomic_add(STRIPE_SECTORS,
+ &rdev->corrected_errors);
+ generic_make_request(bi);
+ } else {
+ if (rw == WRITE)
+ set_bit(STRIPE_DEGRADED, &sh->state);
+ pr_debug("skip op %ld on disc %d for sector %llu\n",
+ bi->bi_rw, i, (unsigned long long)sh->sector);
+ clear_bit(R5_LOCKED, &sh->dev[i].flags);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ }
+ }
+}
+
+static struct dma_async_tx_descriptor *
+async_copy_data(int frombio, struct bio *bio, struct page *page,
+ sector_t sector, struct dma_async_tx_descriptor *tx)
+{
+ struct bio_vec *bvl;
+ struct page *bio_page;
+ int i;
+ int page_offset;
+
+ if (bio->bi_sector >= sector)
+ page_offset = (signed)(bio->bi_sector - sector) * 512;
+ else
+ page_offset = (signed)(sector - bio->bi_sector) * -512;
+ bio_for_each_segment(bvl, bio, i) {
+ int len = bio_iovec_idx(bio, i)->bv_len;
+ int clen;
+ int b_offset = 0;
+
+ if (page_offset < 0) {
+ b_offset = -page_offset;
+ page_offset += b_offset;
+ len -= b_offset;
+ }
+
+ if (len > 0 && page_offset + len > STRIPE_SIZE)
+ clen = STRIPE_SIZE - page_offset;
+ else
+ clen = len;
+
+ if (clen > 0) {
+ b_offset += bio_iovec_idx(bio, i)->bv_offset;
+ bio_page = bio_iovec_idx(bio, i)->bv_page;
+ if (frombio)
+ tx = async_memcpy(page, bio_page, page_offset,
+ b_offset, clen,
+ ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_SRC,
+ tx, NULL, NULL);
+ else
+ tx = async_memcpy(bio_page, page, b_offset,
+ page_offset, clen,
+ ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_DST,
+ tx, NULL, NULL);
+ }
+ if (clen < len) /* hit end of page */
+ break;
+ page_offset += len;
+ }
+
+ return tx;
+}
+
+static void ops_complete_biofill(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+ struct bio *return_bi = NULL;
+ raid5_conf_t *conf = sh->raid_conf;
+ int i, more_to_read = 0;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ /* clear completed biofills */
+ for (i = sh->disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ /* check if this stripe has new incoming reads */
+ if (dev->toread)
+ more_to_read++;
+
+ /* acknowledge completion of a biofill operation */
+ /* and check if we need to reply to a read request
+ */
+ if (test_bit(R5_Wantfill, &dev->flags) && !dev->toread) {
+ struct bio *rbi, *rbi2;
+ clear_bit(R5_Wantfill, &dev->flags);
+
+ /* The access to dev->read is outside of the
+ * spin_lock_irq(&conf->device_lock), but is protected
+ * by the STRIPE_OP_BIOFILL pending bit
+ */
+ BUG_ON(!dev->read);
+ rbi = dev->read;
+ dev->read = NULL;
+ while (rbi && rbi->bi_sector <
+ dev->sector + STRIPE_SECTORS) {
+ rbi2 = r5_next_bio(rbi, dev->sector);
+ spin_lock_irq(&conf->device_lock);
+ if (--rbi->bi_phys_segments == 0) {
+ rbi->bi_next = return_bi;
+ return_bi = rbi;
+ }
+ spin_unlock_irq(&conf->device_lock);
+ rbi = rbi2;
+ }
+ }
+ }
+ clear_bit(STRIPE_OP_BIOFILL, &sh->ops.ack);
+ clear_bit(STRIPE_OP_BIOFILL, &sh->ops.pending);
+
+ return_io(return_bi);
+
+ if (more_to_read)
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static void ops_run_biofill(struct stripe_head *sh)
+{
+ struct dma_async_tx_descriptor *tx = NULL;
+ raid5_conf_t *conf = sh->raid_conf;
+ int i;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ for (i = sh->disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (test_bit(R5_Wantfill, &dev->flags)) {
+ struct bio *rbi;
+ spin_lock_irq(&conf->device_lock);
+ dev->read = rbi = dev->toread;
+ dev->toread = NULL;
+ spin_unlock_irq(&conf->device_lock);
+ while (rbi && rbi->bi_sector <
+ dev->sector + STRIPE_SECTORS) {
+ tx = async_copy_data(0, rbi, dev->page,
+ dev->sector, tx);
+ rbi = r5_next_bio(rbi, dev->sector);
+ }
+ }
+ }
+
+ atomic_inc(&sh->count);
+ async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
+ ops_complete_biofill, sh);
+}
+
+static void ops_complete_compute5(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+ int target = sh->ops.target;
+ struct r5dev *tgt = &sh->dev[target];
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ set_bit(R5_UPTODATE, &tgt->flags);
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
+ clear_bit(R5_Wantcompute, &tgt->flags);
+ set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_compute5(struct stripe_head *sh, unsigned long pending)
+{
+ /* kernel stack size limits the total number of disks */
+ int disks = sh->disks;
+ struct page *xor_srcs[disks];
+ int target = sh->ops.target;
+ struct r5dev *tgt = &sh->dev[target];
+ struct page *xor_dest = tgt->page;
+ int count = 0;
+ struct dma_async_tx_descriptor *tx;
+ int i;
+
+ pr_debug("%s: stripe %llu block: %d\n",
+ __FUNCTION__, (unsigned long long)sh->sector, target);
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
+
+ for (i = disks; i--; )
+ if (i != target)
+ xor_srcs[count++] = sh->dev[i].page;
+
+ atomic_inc(&sh->count);
+
+ if (unlikely(count == 1))
+ tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
+ 0, NULL, ops_complete_compute5, sh);
+ else
+ tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
+ ASYNC_TX_XOR_ZERO_DST, NULL,
+ ops_complete_compute5, sh);
+
+ /* ack now if postxor is not set to be run */
+ if (tx && !test_bit(STRIPE_OP_POSTXOR, &pending))
+ async_tx_ack(tx);
+
+ return tx;
+}
+
+static void ops_complete_prexor(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ set_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+{
+ /* kernel stack size limits the total number of disks */
+ int disks = sh->disks;
+ struct page *xor_srcs[disks];
+ int count = 0, pd_idx = sh->pd_idx, i;
+
+ /* existing parity data subtracted */
+ struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ /* Only process blocks that are known to be uptodate */
+ if (dev->towrite && test_bit(R5_Wantprexor, &dev->flags))
+ xor_srcs[count++] = dev->page;
+ }
+
+ tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
+ ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
+ ops_complete_prexor, sh);
+
+ return tx;
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+{
+ int disks = sh->disks;
+ int pd_idx = sh->pd_idx, i;
+
+ /* check if prexor is active which means only process blocks
+ * that are part of a read-modify-write (Wantprexor)
+ */
+ int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ struct bio *chosen;
+ int towrite;
+
+ towrite = 0;
+ if (prexor) { /* rmw */
+ if (dev->towrite &&
+ test_bit(R5_Wantprexor, &dev->flags))
+ towrite = 1;
+ } else { /* rcw */
+ if (i != pd_idx && dev->towrite &&
+ test_bit(R5_LOCKED, &dev->flags))
+ towrite = 1;
+ }
+
+ if (towrite) {
+ struct bio *wbi;
+
+ spin_lock(&sh->lock);
+ chosen = dev->towrite;
+ dev->towrite = NULL;
+ BUG_ON(dev->written);
+ wbi = dev->written = chosen;
+ spin_unlock(&sh->lock);
+
+ while (wbi && wbi->bi_sector <
+ dev->sector + STRIPE_SECTORS) {
+ tx = async_copy_data(1, wbi, dev->page,
+ dev->sector, tx);
+ wbi = r5_next_bio(wbi, dev->sector);
+ }
+ }
+ }
+
+ return tx;
+}
+
+static void ops_complete_postxor(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static void ops_complete_write(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+ int disks = sh->disks, i, pd_idx = sh->pd_idx;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (dev->written || i == pd_idx)
+ set_bit(R5_UPTODATE, &dev->flags);
+ }
+
+ set_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
+ set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
+
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static void
+ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+{
+ /* kernel stack size limits the total number of disks */
+ int disks = sh->disks;
+ struct page *xor_srcs[disks];
+
+ int count = 0, pd_idx = sh->pd_idx, i;
+ struct page *xor_dest;
+ int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
+ unsigned long flags;
+ dma_async_tx_callback callback;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ /* check if prexor is active which means only process blocks
+ * that are part of a read-modify-write (written)
+ */
+ if (prexor) {
+ xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (dev->written)
+ xor_srcs[count++] = dev->page;
+ }
+ } else {
+ xor_dest = sh->dev[pd_idx].page;
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (i != pd_idx)
+ xor_srcs[count++] = dev->page;
+ }
+ }
+
+ /* check whether this postxor is part of a write */
+ callback = test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending) ?
+ ops_complete_write : ops_complete_postxor;
+
+ /* 1/ if we prexor'd then the dest is reused as a source
+ * 2/ if we did not prexor then we are redoing the parity
+ * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
+ * for the synchronous xor case
+ */
+ flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
+ (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
+
+ atomic_inc(&sh->count);
+
+ if (unlikely(count == 1)) {
+ flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
+ tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
+ flags, tx, callback, sh);
+ } else
+ tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
+ flags, tx, callback, sh);
+}
+
+static void ops_complete_check(void *stripe_head_ref)
+{
+ struct stripe_head *sh = stripe_head_ref;
+ int pd_idx = sh->pd_idx;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ if (test_and_clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending) &&
+ sh->ops.zero_sum_result == 0)
+ set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
+
+ set_bit(STRIPE_OP_CHECK, &sh->ops.complete);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static void ops_run_check(struct stripe_head *sh)
+{
+ /* kernel stack size limits the total number of disks */
+ int disks = sh->disks;
+ struct page *xor_srcs[disks];
+ struct dma_async_tx_descriptor *tx;
+
+ int count = 0, pd_idx = sh->pd_idx, i;
+ struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
+
+ pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ (unsigned long long)sh->sector);
+
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (i != pd_idx)
+ xor_srcs[count++] = dev->page;
+ }
+
+ tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
+ &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
+
+ if (tx)
+ set_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
+ else
+ clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
+
+ atomic_inc(&sh->count);
+ tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
+ ops_complete_check, sh);
+}
+
+static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
+{
+ int overlap_clear = 0, i, disks = sh->disks;
+ struct dma_async_tx_descriptor *tx = NULL;
+
+ if (test_bit(STRIPE_OP_BIOFILL, &pending)) {
+ ops_run_biofill(sh);
+ overlap_clear++;
+ }
+
+ if (test_bit(STRIPE_OP_COMPUTE_BLK, &pending))
+ tx = ops_run_compute5(sh, pending);
+
+ if (test_bit(STRIPE_OP_PREXOR, &pending))
+ tx = ops_run_prexor(sh, tx);
+
+ if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
+ tx = ops_run_biodrain(sh, tx);
+ overlap_clear++;
+ }
+
+ if (test_bit(STRIPE_OP_POSTXOR, &pending))
+ ops_run_postxor(sh, tx);
+
+ if (test_bit(STRIPE_OP_CHECK, &pending))
+ ops_run_check(sh);
+
+ if (test_bit(STRIPE_OP_IO, &pending))
+ ops_run_io(sh);
+
+ if (overlap_clear)
+ for (i = disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ if (test_and_clear_bit(R5_Overlap, &dev->flags))
+ wake_up(&sh->raid_conf->wait_for_overlap);
+ }
+}
+
static int grow_one_stripe(raid5_conf_t *conf)
{
struct stripe_head *sh;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-14 20:31:13 +0000