Add a new function raid5_gen_result() to calculate raid5 parity or
recover data stripe.
Since now that raid6.c handles both raid5 and raid6, rename it to
raid56.c.
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
Makefile.in | 2 +-
disk-io.h | 3 ++-
raid6.c => raid56.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
volumes.c | 36 +++++++++++++++---------------------
4 files changed, 63 insertions(+), 23 deletions(-)
rename raid6.c => raid56.c (71%)
diff --git a/Makefile.in b/Makefile.in
index 20b740a..0ae2cd5 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -90,7 +90,7 @@ CHECKER_FLAGS := -include $(check_defs) -D__CHECKER__ \
objects = ctree.o disk-io.o kernel-lib/radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
extent-cache.o extent_io.o volumes.o utils.o repair.o \
- qgroup.o raid6.o free-space-cache.o kernel-lib/list_sort.o props.o \
+ qgroup.o raid56.o free-space-cache.o kernel-lib/list_sort.o props.o \
ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \
inode.o file.o find-root.o free-space-tree.o help.o
cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
diff --git a/disk-io.h b/disk-io.h
index 1080fc1..9fc7e92 100644
--- a/disk-io.h
+++ b/disk-io.h
@@ -190,7 +190,8 @@ int write_tree_block(struct btrfs_trans_handle *trans,
int write_and_map_eb(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *eb);
-/* raid6.c */
+/* raid56.c */
void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
+int raid5_gen_result(int nr_devs, size_t stripe_len, int dest, void **data);
#endif
diff --git a/raid6.c b/raid56.c
similarity index 71%
rename from raid6.c
rename to raid56.c
index 833df5f..2953d61 100644
--- a/raid6.c
+++ b/raid56.c
@@ -26,6 +26,7 @@
#include "kerncompat.h"
#include "ctree.h"
#include "disk-io.h"
+#include "utils.h"
/*
* This is the C data type to use
@@ -107,3 +108,47 @@ void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs)
}
}
+static void xor_range(void *src, void *dst, size_t size)
+{
+ while (size) {
+ *(unsigned long *) dst ^= *(unsigned long *) src;
+ src += sizeof(unsigned long);
+ dst += sizeof(unsigned long);
+ size -= sizeof(unsigned long);
+ }
+}
+
+/*
+ * Generate desired data/parity for RAID5
+ *
+ * @nr_devs: Total number of devices, including parity
+ * @stripe_len: Stripe length
+ * @data: Data, with special layout:
+ * data[0]: Data stripe 0
+ * data[nr_devs-2]: Last data stripe
+ * data[nr_devs-1]: RAID5 parity
+ * @dest: To generate which data. should follow above data layout
+ */
+int raid5_gen_result(int nr_devs, size_t stripe_len, int dest, void **data)
+{
+ int i;
+ char *buf = data[dest];
+
+ if (dest >= nr_devs || nr_devs < 2) {
+ error("invalid parameter for %s", __func__);
+ return -EINVAL;
+ }
+ /* Quich hack, 2 devs RAID5 is just RAID1, no need to calculate */
+ if (nr_devs == 2) {
+ memcpy(data[dest], data[1 - dest], stripe_len);
+ return 0;
+ }
+ /* Just in case */
+ memset(buf, 0, stripe_len);
+ for (i = 0; i < nr_devs; i++) {
+ if (i == dest)
+ continue;
+ xor_range(data[i], buf, stripe_len);
+ }
+ return 0;
+}
diff --git a/volumes.c b/volumes.c
index da79751..718e67c 100644
--- a/volumes.c
+++ b/volumes.c
@@ -2108,12 +2108,14 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
{
struct extent_buffer **ebs, *p_eb = NULL, *q_eb = NULL;
int i;
- int j;
int ret;
int alloc_size = eb->len;
+ void **pointers;
- ebs = kmalloc(sizeof(*ebs) * multi->num_stripes, GFP_NOFS);
- BUG_ON(!ebs);
+ ebs = malloc(sizeof(*ebs) * multi->num_stripes);
+ pointers = malloc(sizeof(void *) * multi->num_stripes);
+ if (!ebs || !pointers)
+ return -ENOMEM;
if (stripe_len > alloc_size)
alloc_size = stripe_len;
@@ -2143,12 +2145,6 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
q_eb = new_eb;
}
if (q_eb) {
- void **pointers;
-
- pointers = kmalloc(sizeof(*pointers) * multi->num_stripes,
- GFP_NOFS);
- BUG_ON(!pointers);
-
ebs[multi->num_stripes - 2] = p_eb;
ebs[multi->num_stripes - 1] = q_eb;
@@ -2159,17 +2155,14 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
kfree(pointers);
} else {
ebs[multi->num_stripes - 1] = p_eb;
- memcpy(p_eb->data, ebs[0]->data, stripe_len);
- for (j = 1; j < multi->num_stripes - 1; j++) {
- for (i = 0; i < stripe_len; i += sizeof(u64)) {
- u64 p_eb_data;
- u64 ebs_data;
-
- p_eb_data = get_unaligned_64(p_eb->data + i);
- ebs_data = get_unaligned_64(ebs[j]->data + i);
- p_eb_data ^= ebs_data;
- put_unaligned_64(p_eb_data, p_eb->data + i);
- }
+ for (i = 0; i < multi->num_stripes; i++)
+ pointers[i] = ebs[i]->data;
+ ret = raid5_gen_result(multi->num_stripes, stripe_len,
+ multi->num_stripes - 1, pointers);
+ if (ret < 0) {
+ free(ebs);
+ free(pointers);
+ return ret;
}
}
@@ -2180,7 +2173,8 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
kfree(ebs[i]);
}
- kfree(ebs);
+ free(ebs);
+ free(pointers);
return 0;
}
--
2.10.0
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