Btrfs, replace: write dirty pages into the replace target device
The implementation is simple:
- In order to avoid changing the code logic of btrfs_map_bio and
RAID56, we add the stripes of the replace target devices at the
end of the stripe array in btrfs bio, and we sort those target
device stripes in the array. And we keep the number of the target
device stripes in the btrfs bio.
- Except write operation on RAID56, all the other operation don't
take the target device stripes into account.
- When we do write operation, we read the data from the common devices
and calculate the parity. Then write the dirty data and new parity
out, at this time, we will find the relative replace target stripes
and wirte the relative data into it.
Note: The function that copying old data on the source device to
the target device was implemented in the past, it is similar to
the other RAID type.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index b85d68f..89a8486 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -131,6 +131,8 @@
/* number of data stripes (no p/q) */
int nr_data;
+ int real_stripes;
+
int stripe_npages;
/*
* set if we're doing a parity rebuild
@@ -638,7 +640,7 @@
*/
static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index)
{
- if (rbio->nr_data + 1 == rbio->bbio->num_stripes)
+ if (rbio->nr_data + 1 == rbio->real_stripes)
return NULL;
index += ((rbio->nr_data + 1) * rbio->stripe_len) >>
@@ -981,7 +983,8 @@
{
struct btrfs_raid_bio *rbio;
int nr_data = 0;
- int num_pages = rbio_nr_pages(stripe_len, bbio->num_stripes);
+ int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
+ int num_pages = rbio_nr_pages(stripe_len, real_stripes);
int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE);
void *p;
@@ -1001,6 +1004,7 @@
rbio->fs_info = root->fs_info;
rbio->stripe_len = stripe_len;
rbio->nr_pages = num_pages;
+ rbio->real_stripes = real_stripes;
rbio->stripe_npages = stripe_npages;
rbio->faila = -1;
rbio->failb = -1;
@@ -1017,10 +1021,10 @@
rbio->bio_pages = p + sizeof(struct page *) * num_pages;
rbio->dbitmap = p + sizeof(struct page *) * num_pages * 2;
- if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
- nr_data = bbio->num_stripes - 2;
+ if (raid_map[real_stripes - 1] == RAID6_Q_STRIPE)
+ nr_data = real_stripes - 2;
else
- nr_data = bbio->num_stripes - 1;
+ nr_data = real_stripes - 1;
rbio->nr_data = nr_data;
return rbio;
@@ -1132,7 +1136,7 @@
static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio)
{
if (rbio->faila >= 0 || rbio->failb >= 0) {
- BUG_ON(rbio->faila == rbio->bbio->num_stripes - 1);
+ BUG_ON(rbio->faila == rbio->real_stripes - 1);
__raid56_parity_recover(rbio);
} else {
finish_rmw(rbio);
@@ -1193,7 +1197,7 @@
static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
{
struct btrfs_bio *bbio = rbio->bbio;
- void *pointers[bbio->num_stripes];
+ void *pointers[rbio->real_stripes];
int stripe_len = rbio->stripe_len;
int nr_data = rbio->nr_data;
int stripe;
@@ -1207,11 +1211,11 @@
bio_list_init(&bio_list);
- if (bbio->num_stripes - rbio->nr_data == 1) {
- p_stripe = bbio->num_stripes - 1;
- } else if (bbio->num_stripes - rbio->nr_data == 2) {
- p_stripe = bbio->num_stripes - 2;
- q_stripe = bbio->num_stripes - 1;
+ if (rbio->real_stripes - rbio->nr_data == 1) {
+ p_stripe = rbio->real_stripes - 1;
+ } else if (rbio->real_stripes - rbio->nr_data == 2) {
+ p_stripe = rbio->real_stripes - 2;
+ q_stripe = rbio->real_stripes - 1;
} else {
BUG();
}
@@ -1268,7 +1272,7 @@
SetPageUptodate(p);
pointers[stripe++] = kmap(p);
- raid6_call.gen_syndrome(bbio->num_stripes, PAGE_SIZE,
+ raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
pointers);
} else {
/* raid5 */
@@ -1277,7 +1281,7 @@
}
- for (stripe = 0; stripe < bbio->num_stripes; stripe++)
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++)
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
}
@@ -1286,7 +1290,7 @@
* higher layers (the bio_list in our rbio) and our p/q. Ignore
* everything else.
*/
- for (stripe = 0; stripe < bbio->num_stripes; stripe++) {
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) {
struct page *page;
if (stripe < rbio->nr_data) {
@@ -1304,6 +1308,32 @@
}
}
+ if (likely(!bbio->num_tgtdevs))
+ goto write_data;
+
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
+ if (!bbio->tgtdev_map[stripe])
+ continue;
+
+ for (pagenr = 0; pagenr < pages_per_stripe; pagenr++) {
+ struct page *page;
+ if (stripe < rbio->nr_data) {
+ page = page_in_rbio(rbio, stripe, pagenr, 1);
+ if (!page)
+ continue;
+ } else {
+ page = rbio_stripe_page(rbio, stripe, pagenr);
+ }
+
+ ret = rbio_add_io_page(rbio, &bio_list, page,
+ rbio->bbio->tgtdev_map[stripe],
+ pagenr, rbio->stripe_len);
+ if (ret)
+ goto cleanup;
+ }
+ }
+
+write_data:
atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list));
BUG_ON(atomic_read(&rbio->stripes_pending) == 0);
@@ -1342,7 +1372,8 @@
stripe = &rbio->bbio->stripes[i];
stripe_start = stripe->physical;
if (physical >= stripe_start &&
- physical < stripe_start + rbio->stripe_len) {
+ physical < stripe_start + rbio->stripe_len &&
+ bio->bi_bdev == stripe->dev->bdev) {
return i;
}
}
@@ -1791,7 +1822,7 @@
int err;
int i;
- pointers = kzalloc(rbio->bbio->num_stripes * sizeof(void *),
+ pointers = kzalloc(rbio->real_stripes * sizeof(void *),
GFP_NOFS);
if (!pointers) {
err = -ENOMEM;
@@ -1821,7 +1852,7 @@
/* setup our array of pointers with pages
* from each stripe
*/
- for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) {
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
/*
* if we're rebuilding a read, we have to use
* pages from the bio list
@@ -1836,7 +1867,7 @@
}
/* all raid6 handling here */
- if (rbio->raid_map[rbio->bbio->num_stripes - 1] ==
+ if (rbio->raid_map[rbio->real_stripes - 1] ==
RAID6_Q_STRIPE) {
/*
@@ -1886,10 +1917,10 @@
}
if (rbio->raid_map[failb] == RAID5_P_STRIPE) {
- raid6_datap_recov(rbio->bbio->num_stripes,
+ raid6_datap_recov(rbio->real_stripes,
PAGE_SIZE, faila, pointers);
} else {
- raid6_2data_recov(rbio->bbio->num_stripes,
+ raid6_2data_recov(rbio->real_stripes,
PAGE_SIZE, faila, failb,
pointers);
}
@@ -1931,7 +1962,7 @@
}
}
}
- for (stripe = 0; stripe < rbio->bbio->num_stripes; stripe++) {
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
/*
* if we're rebuilding a read, we have to use
* pages from the bio list
@@ -2012,7 +2043,6 @@
static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
{
int bios_to_read = 0;
- struct btrfs_bio *bbio = rbio->bbio;
struct bio_list bio_list;
int ret;
int nr_pages = DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE);
@@ -2033,7 +2063,7 @@
* stripe cache, it is possible that some or all of these
* pages are going to be uptodate.
*/
- for (stripe = 0; stripe < bbio->num_stripes; stripe++) {
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
if (rbio->faila == stripe || rbio->failb == stripe) {
atomic_inc(&rbio->error);
continue;
@@ -2139,7 +2169,7 @@
* asking for mirror 3
*/
if (mirror_num == 3)
- rbio->failb = bbio->num_stripes - 2;
+ rbio->failb = rbio->real_stripes - 2;
ret = lock_stripe_add(rbio);
@@ -2205,7 +2235,7 @@
ASSERT(!bio->bi_iter.bi_size);
rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
- for (i = 0; i < bbio->num_stripes; i++) {
+ for (i = 0; i < rbio->real_stripes; i++) {
if (bbio->stripes[i].dev == scrub_dev) {
rbio->scrubp = i;
break;
@@ -2246,7 +2276,7 @@
struct page *page;
for_each_set_bit(bit, rbio->dbitmap, rbio->stripe_npages) {
- for (i = 0; i < rbio->bbio->num_stripes; i++) {
+ for (i = 0; i < rbio->real_stripes; i++) {
index = i * rbio->stripe_npages + bit;
if (rbio->stripe_pages[index])
continue;
@@ -2288,8 +2318,7 @@
static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
int need_check)
{
- struct btrfs_bio *bbio = rbio->bbio;
- void *pointers[bbio->num_stripes];
+ void *pointers[rbio->real_stripes];
int nr_data = rbio->nr_data;
int stripe;
int pagenr;
@@ -2303,11 +2332,11 @@
bio_list_init(&bio_list);
- if (bbio->num_stripes - rbio->nr_data == 1) {
- p_stripe = bbio->num_stripes - 1;
- } else if (bbio->num_stripes - rbio->nr_data == 2) {
- p_stripe = bbio->num_stripes - 2;
- q_stripe = bbio->num_stripes - 1;
+ if (rbio->real_stripes - rbio->nr_data == 1) {
+ p_stripe = rbio->real_stripes - 1;
+ } else if (rbio->real_stripes - rbio->nr_data == 2) {
+ p_stripe = rbio->real_stripes - 2;
+ q_stripe = rbio->real_stripes - 1;
} else {
BUG();
}
@@ -2358,7 +2387,7 @@
*/
pointers[stripe++] = kmap(q_page);
- raid6_call.gen_syndrome(bbio->num_stripes, PAGE_SIZE,
+ raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
pointers);
} else {
/* raid5 */
@@ -2376,7 +2405,7 @@
bitmap_clear(rbio->dbitmap, pagenr, 1);
kunmap(p);
- for (stripe = 0; stripe < bbio->num_stripes; stripe++)
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++)
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
}
@@ -2526,7 +2555,6 @@
static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio)
{
int bios_to_read = 0;
- struct btrfs_bio *bbio = rbio->bbio;
struct bio_list bio_list;
int ret;
int pagenr;
@@ -2544,7 +2572,7 @@
* build a list of bios to read all the missing parts of this
* stripe
*/
- for (stripe = 0; stripe < bbio->num_stripes; stripe++) {
+ for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
struct page *page;
/*
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 217c42e..6d8a5e8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4881,13 +4881,15 @@
static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
{
struct btrfs_bio_stripe s;
+ int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
int i;
u64 l;
int again = 1;
+ int m;
while (again) {
again = 0;
- for (i = 0; i < bbio->num_stripes - 1; i++) {
+ for (i = 0; i < real_stripes - 1; i++) {
if (parity_smaller(raid_map[i], raid_map[i+1])) {
s = bbio->stripes[i];
l = raid_map[i];
@@ -4895,6 +4897,14 @@
raid_map[i] = raid_map[i+1];
bbio->stripes[i+1] = s;
raid_map[i+1] = l;
+
+ if (bbio->tgtdev_map) {
+ m = bbio->tgtdev_map[i];
+ bbio->tgtdev_map[i] =
+ bbio->tgtdev_map[i + 1];
+ bbio->tgtdev_map[i + 1] = m;
+ }
+
again = 1;
}
}
@@ -4923,6 +4933,7 @@
int ret = 0;
int num_stripes;
int max_errors = 0;
+ int tgtdev_indexes = 0;
struct btrfs_bio *bbio = NULL;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
int dev_replace_is_ongoing = 0;
@@ -5234,14 +5245,19 @@
num_alloc_stripes <<= 1;
if (rw & REQ_GET_READ_MIRRORS)
num_alloc_stripes++;
+ tgtdev_indexes = num_stripes;
}
- bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
+
+ bbio = kzalloc(btrfs_bio_size(num_alloc_stripes, tgtdev_indexes),
+ GFP_NOFS);
if (!bbio) {
kfree(raid_map);
ret = -ENOMEM;
goto out;
}
atomic_set(&bbio->error, 0);
+ if (dev_replace_is_ongoing)
+ bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes);
if (rw & REQ_DISCARD) {
int factor = 0;
@@ -5326,6 +5342,7 @@
if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
max_errors = btrfs_chunk_max_errors(map);
+ tgtdev_indexes = 0;
if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
dev_replace->tgtdev != NULL) {
int index_where_to_add;
@@ -5354,8 +5371,10 @@
new->physical = old->physical;
new->length = old->length;
new->dev = dev_replace->tgtdev;
+ bbio->tgtdev_map[i] = index_where_to_add;
index_where_to_add++;
max_errors++;
+ tgtdev_indexes++;
}
}
num_stripes = index_where_to_add;
@@ -5401,7 +5420,9 @@
tgtdev_stripe->length =
bbio->stripes[index_srcdev].length;
tgtdev_stripe->dev = dev_replace->tgtdev;
+ bbio->tgtdev_map[index_srcdev] = num_stripes;
+ tgtdev_indexes++;
num_stripes++;
}
}
@@ -5411,6 +5432,7 @@
bbio->num_stripes = num_stripes;
bbio->max_errors = max_errors;
bbio->mirror_num = mirror_num;
+ bbio->num_tgtdevs = tgtdev_indexes;
/*
* this is the case that REQ_READ && dev_replace_is_ongoing &&
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 01094bb..70be257 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -292,7 +292,7 @@
struct btrfs_bio;
typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
-#define BTRFS_BIO_ORIG_BIO_SUBMITTED 0x1
+#define BTRFS_BIO_ORIG_BIO_SUBMITTED (1 << 0)
struct btrfs_bio {
atomic_t stripes_pending;
@@ -305,6 +305,8 @@
int max_errors;
int num_stripes;
int mirror_num;
+ int num_tgtdevs;
+ int *tgtdev_map;
struct btrfs_bio_stripe stripes[];
};
@@ -387,8 +389,10 @@
int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
u64 end, u64 *length);
-#define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
- (sizeof(struct btrfs_bio_stripe) * (n)))
+#define btrfs_bio_size(total_stripes, real_stripes) \
+ (sizeof(struct btrfs_bio) + \
+ (sizeof(struct btrfs_bio_stripe) * (total_stripes)) + \
+ (sizeof(int) * (real_stripes)))
int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
u64 logical, u64 *length,