On Mon, 2006-11-20 at 20:54 +0000, Hugh Dickins wrote:
> Not found anything relevant, but I keep noticing these lines
> in ext2_try_to_allocate_with_rsv(), ext3 and ext4 similar:
>
> } else if (grp_goal > 0 &&
> (my_rsv->rsv_end - grp_goal + 1) < *count)
> try_to_extend_reservation(my_rsv, sb,
> *count-my_rsv->rsv_end + grp_goal - 1);
>
> They're wrong, a no-op in most groups, aren't they? rsv_end is an
> absolute block number, whereas grp_goal is group-relative, so the
> calculation ought to bring in group_first_block? Or I'm confused.
>
You are right, thanks. Here are two patches, to fix this bug in ext3/4
and ext2 correspondingly.
Signed-Off-By: Mingming Cao <cmm@xxxxxxxxxx>
---
linux-2.6.19-rc5-cmm/fs/ext3/balloc.c | 12 ++++++++----
linux-2.6.19-rc5-cmm/fs/ext4/balloc.c | 12 ++++++++----
2 files changed, 16 insertions(+), 8 deletions(-)
diff -puN fs/ext3/balloc.c~ext34_extend_reservation_window_fix fs/ext3/balloc.c
--- linux-2.6.19-rc5/fs/ext3/balloc.c~ext34_extend_reservation_window_fix 2006-11-20 15:58:11.000000000 -0800
+++ linux-2.6.19-rc5-cmm/fs/ext3/balloc.c 2006-11-20 15:58:11.000000000 -0800
@@ -1307,10 +1307,14 @@ ext3_try_to_allocate_with_rsv(struct sup
if (!goal_in_my_reservation(&my_rsv->rsv_window,
grp_goal, group, sb))
grp_goal = -1;
- } else if (grp_goal > 0 &&
- (my_rsv->rsv_end-grp_goal+1) < *count)
- try_to_extend_reservation(my_rsv, sb,
- *count-my_rsv->rsv_end + grp_goal - 1);
+ } else if (grp_goal > 0) {
+ int curr = my_rsv->rsv_end -
+ (grp_goal + group_first_block) + 1;
+
+ if (curr < *count)
+ try_to_extend_reservation(my_rsv, sb,
+ *count - curr);
+ }
if ((my_rsv->rsv_start > group_last_block) ||
(my_rsv->rsv_end < group_first_block)) {
diff -puN fs/ext4/balloc.c~ext34_extend_reservation_window_fix fs/ext4/balloc.c
--- linux-2.6.19-rc5/fs/ext4/balloc.c~ext34_extend_reservation_window_fix 2006-11-20 15:58:11.000000000 -0800
+++ linux-2.6.19-rc5-cmm/fs/ext4/balloc.c 2006-11-20 15:58:11.000000000 -0800
@@ -1324,10 +1324,14 @@ ext4_try_to_allocate_with_rsv(struct sup
if (!goal_in_my_reservation(&my_rsv->rsv_window,
grp_goal, group, sb))
grp_goal = -1;
- } else if (grp_goal > 0 &&
- (my_rsv->rsv_end-grp_goal+1) < *count)
- try_to_extend_reservation(my_rsv, sb,
- *count-my_rsv->rsv_end + grp_goal - 1);
+ } else if (grp_goal > 0) {
+ int curr = my_rsv->rsv_end -
+ (grp_goal + group_first_block) + 1;
+
+ if (curr < *count)
+ try_to_extend_reservation(my_rsv, sb,
+ *count - curr);
+ }
if ((my_rsv->rsv_start > group_last_block) ||
(my_rsv->rsv_end < group_first_block)) {
Sync up ext2 with ext3/4 for the extend reservation window bug.
Signed-Off-By: Mingming Cao <cmm@xxxxxxxxxx>
---
linux-2.6.19-rc5-cmm/fs/ext2/balloc.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff -puN fs/ext2/balloc.c~ext2_reservation_extend_window_fix fs/ext2/balloc.c
--- linux-2.6.19-rc5/fs/ext2/balloc.c~ext2_reservation_extend_window_fix 2006-11-20 16:05:36.000000000 -0800
+++ linux-2.6.19-rc5-cmm/fs/ext2/balloc.c 2006-11-20 16:05:36.000000000 -0800
@@ -1091,10 +1091,14 @@ ext2_try_to_allocate_with_rsv(struct sup
if (!goal_in_my_reservation(&my_rsv->rsv_window,
grp_goal, group, sb))
grp_goal = -1;
- } else if (grp_goal > 0 &&
- (my_rsv->rsv_end - grp_goal + 1) < *count)
- try_to_extend_reservation(my_rsv, sb,
- *count-my_rsv->rsv_end + grp_goal - 1);
+ } else if (grp_goal > 0) {
+ int curr = my_rsv->rsv_end -
+ (grp_goal + group_first_block) + 1;
+
+ if (curr < *count)
+ try_to_extend_reservation(my_rsv, sb,
+ *count - curr);
+ }
if ((my_rsv->rsv_start >=
group_first_block + EXT2_BLOCKS_PER_GROUP(sb))
_
-
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