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authorMiao Xie <miaox@cn.fujitsu.com>2014-11-14 11:06:25 +0300
committerMiao Xie <miaox@cn.fujitsu.com>2014-12-03 05:18:46 +0300
commit2c8cdd6ee4e7f637b0486c6798117e7859dee586 (patch)
treeae10c7af5f98e4b60d55676b8d59b8b543980ae8 /fs/btrfs/volumes.c
parent5a6ac9eacb49143cbad3bbfda72263101cb1f3df (diff)
downloadlinux-2c8cdd6ee4e7f637b0486c6798117e7859dee586.tar.xz
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>
Diffstat (limited to 'fs/btrfs/volumes.c')
-rw-r--r--fs/btrfs/volumes.c26
1 files changed, 24 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 217c42ea90b0..6d8a5e8d8c39 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4881,13 +4881,15 @@ static inline int parity_smaller(u64 a, u64 b)
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 @@ static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
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 &&