From a0dd59de3c73fbb3b738eaf333732f2f27254a2c Mon Sep 17 00:00:00 2001 From: Zhao Lei Date: Tue, 21 Jul 2015 15:42:26 +0800 Subject: [PATCH] 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 Signed-off-by: Chris Mason --- fs/btrfs/scrub.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 6987de6b1ed8..185595a7be10 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2702,7 +2702,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity) 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 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, 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 @@ next: 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 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 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 @@ loop: 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, -- 2.20.1