This patch changes btrfs/raid56.c to use the new raid interface and
extends its support to an arbitrary number of parities.
More in details, the two faila/failb failure indexes are now replaced
with a fail[] vector that keeps track of up to six failures, and now
the new raid_par() and raid_rec() functions are used to handle with
parity instead of the old xor/raid6 ones.
Signed-off-by: Andrea Mazzoleni
---
fs/btrfs/Kconfig | 1 +
fs/btrfs/raid56.c | 278 ++---
fs/btrfs/raid56.h | 12 ++-
fs/btrfs/volumes.c | 4 +-
4 files changed, 102 insertions(+), 193 deletions(-)
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index aa976ec..173fabe 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -5,6 +5,7 @@ config BTRFS_FS
select ZLIB_DEFLATE
select LZO_COMPRESS
select LZO_DECOMPRESS
+ select RAID_CAUCHY
select RAID6_PQ
select XOR_BLOCKS
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 24ac218..2ceff3a 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -27,10 +27,9 @@
#include
#include
#include
-#include
+#include
#include
#include
-#include
#include
#include
#include "ctree.h"
@@ -125,11 +124,11 @@ struct btrfs_raid_bio {
*/
int read_rebuild;
- /* first bad stripe */
- int faila;
+ /* bad stripes */
+ int fail[RAID_PARITY_MAX];
- /* second bad stripe (for raid6 use) */
- int failb;
+ /* number of bad stripes in fail[] */
+ int nr_fail;
/*
* number of pages needed to represent the full
@@ -496,26 +495,6 @@ static void cache_rbio(struct btrfs_raid_bio *rbio)
}
/*
- * helper function to run the xor_blocks api. It is only
- * able to do MAX_XOR_BLOCKS at a time, so we need to
- * loop through.
- */
-static void run_xor(void **pages, int src_cnt, ssize_t len)
-{
- int src_off = 0;
- int xor_src_cnt = 0;
- void *dest = pages[src_cnt];
-
- while(src_cnt > 0) {
- xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
- xor_blocks(xor_src_cnt, len, dest, pages + src_off);
-
- src_cnt -= xor_src_cnt;
- src_off += xor_src_cnt;
- }
-}
-
-/*
* returns true if the bio list inside this rbio
* covers an entire stripe (no rmw required).
* Must be called with the bio list lock held, or
@@ -587,25 +566,18 @@ static int rbio_can_merge(struct btrfs_raid_bio *last,
}
/*
- * helper to index into the pstripe
+ * helper to index into the parity stripe
+ * returns null if there is no stripe
*/
-static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index)
+static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio,
+ int index, int parity)
{
- index += (rbio->nr_data * rbio->stripe_len) >> PAGE_CACHE_SHIFT;
- return rbio->stripe_pages[index];
-}
-
-/*
- * helper to index into the qstripe, returns null
- * if there is no qstripe
- */
-static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index)
-{
- if (rbio->nr_data + 1 == rbio->bbio->num_stripes)
+ if (rbio->nr_data + parity >= rbio->bbio->num_stripes)
return NULL;
- index += ((rbio->nr_data + 1) * rbio->stripe_len) >>
- PAGE_CACHE_SHIFT;
+ index += ((rbio->nr_data + parity) * rbio->stripe_len)
+ >> PAGE_CACHE_SHIFT;
+
return rbio->stripe_pages[index];
}
@@ -946,8 +918,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_root
*root,
rbio->fs_info = root->fs_info;
rbio->stripe_len = stripe_len;
rbio->nr_pages = num_pages;
- rbio->faila = -1;
- rbio->failb = -1;
+ rbio->nr_fail = 0;
atomic_set(&rbio->refs, 1);
/*
@@ -958,10 +929,10 @@ static struct btrfs_raid_bio *alloc_rbio(struct
btrfs_root *root,
rbio->stripe_pages = p;
rbio->bio_pages = p + sizeof(struct page *) * num_pages;
- if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
- nr_data = bbio->num_stripes - 2;
- else
- nr_data = bbio->num_stripes - 1;
+ /* get the number of data stripes removing all the parities */
+ nr_data = bbio->num_stripes;
+ while (nr_data > 0 && is_parity_stripe(raid_map[nr_data - 1]))
+ --nr_data;
rbio->nr_data = nr_data;
return rbio;
@@ -1072,8 +1043,7 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
*/
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);
+ if (rbio->nr_fail > 0) {
__raid56_parity_recover(rbio);
} else {
finish_rmw(rbio);
@@ -1137,10 +1107,10 @@ static noinline void finish_rmw(struct btrfs_raid_bio
*rbio)
void *pointers[bbio->num_stripes];
int stripe_l
