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)) _ - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html