btrfs: Fix calculate typo caused by ambiguous meaning of logic_end
For example, in scrub_raid56_parity(), following lines are used
to judge is all data processed:
place1: if (key.objectid > logic_end) ...
place2: if (logic_start >= logic_end) ...
...
(place2 is typo, is should be ">", it is copied from other
place, where logic_end's meaning is different, long story...)
We can fix above typo directly, but the root reason is ambiguous
meaning of logic_end in scrub raid56 parity.
In other place, XXX_end is pointed to data which is not included,
and we need to process segment of [XXX_start, XXX_end).
But for scrub raid56 parity, logic_end is pointed to lattest data
need to process, and introduced many "+ 1" and "- 1" in code as
below:
length = sparity->logic_end - sparity->logic_start + 1
logic_end - logic_start + 1
stripe_logical + increment - 1
This patch changed logic_end's meaning to make it in normal understanding
in raid56 parity functions and data struct alone with above bugfix.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 6987de6..185595a 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2702,7 +2702,7 @@
sparity->nsectors))
goto out;
- length = sparity->logic_end - sparity->logic_start + 1;
+ length = sparity->logic_end - sparity->logic_start;
ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
sparity->logic_start,
&length, &bbio, 0, 1);
@@ -2868,7 +2868,7 @@
key.type != BTRFS_METADATA_ITEM_KEY)
goto next;
- if (key.objectid > logic_end) {
+ if (key.objectid >= logic_end) {
stop_loop = 1;
break;
}
@@ -2958,7 +2958,7 @@
out:
if (ret < 0)
scrub_parity_mark_sectors_error(sparity, logic_start,
- logic_end - logic_start + 1);
+ logic_end - logic_start);
scrub_parity_put(sparity);
scrub_submit(sctx);
mutex_lock(&sctx->wr_ctx.wr_lock);
@@ -3139,7 +3139,7 @@
logical += base;
if (ret) {
stripe_logical += base;
- stripe_end = stripe_logical + increment - 1;
+ stripe_end = stripe_logical + increment;
ret = scrub_raid56_parity(sctx, map, scrub_dev,
ppath, stripe_logical,
stripe_end);
@@ -3287,7 +3287,7 @@
if (ret && physical < physical_end) {
stripe_logical += base;
stripe_end = stripe_logical +
- increment - 1;
+ increment;
ret = scrub_raid56_parity(sctx,
map, scrub_dev, ppath,
stripe_logical,