From 1dea84ae38288fbefa04d9fda2b3f36c21a9e1bd Mon Sep 17 00:00:00 2001 From: Mariusz Tkaczyk Date: Mon, 29 May 2023 15:52:38 +0200 Subject: imsm: fix free space calculations Between two volumes or between last volume and metadata at least IMSM_RESERVED_SECTORS gap must exist. Currently the gap can be doubled because metadata reservation contains IMSM_RESERVED_SECTORS too. Divide reserve variable into pre_reservation and post_reservation to be more flexible and decide separately if each reservation is needed. Pre_reservation is needed only when a volume is created and it is not a real first volume in a container (we can check that by extent_idx). This type of reservation is not needed for expand. Post_reservation is not needed only if real last volume is created or expanded because reservation is done with the metadata. The volume index in metadata cannot be trusted, because the real volume order can be reversed. It is safer to use extent table, it is sorted by start position. Signed-off-by: Mariusz Tkaczyk Signed-off-by: Jes Sorensen --- super-intel.c | 50 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/super-intel.c b/super-intel.c index e249d925..824c1356 100644 --- a/super-intel.c +++ b/super-intel.c @@ -6919,8 +6919,11 @@ static unsigned long long merge_extents(struct intel_super *super, const bool ex int sum_extents = 0; unsigned long long pos = 0; unsigned long long start = 0; - unsigned long long maxsize = 0; - unsigned long reserve; + unsigned long long free_size = 0; + + unsigned long pre_reservation = 0; + unsigned long post_reservation = IMSM_RESERVED_SECTORS; + unsigned long reservation_size; for (dl = super->disks; dl; dl = dl->next) if (dl->e) @@ -6955,8 +6958,8 @@ static unsigned long long merge_extents(struct intel_super *super, const bool ex do { unsigned long long esize = e[i].start - pos; - if (expanding ? pos_vol_idx == super->current_vol : esize >= maxsize) { - maxsize = esize; + if (expanding ? pos_vol_idx == super->current_vol : esize >= free_size) { + free_size = esize; start = pos; extent_idx = i; } @@ -6966,28 +6969,35 @@ static unsigned long long merge_extents(struct intel_super *super, const bool ex i++; } while (e[i-1].size); - free(e); - if (maxsize == 0) + if (free_size == 0) { + dprintf("imsm: Cannot find free size.\n"); + free(e); return 0; + } - /* FIXME assumes volume at offset 0 is the first volume in a - * container - */ - if (extent_idx > 0) - reserve = IMSM_RESERVED_SECTORS; /* gap between raid regions */ - else - reserve = 0; + if (!expanding && extent_idx != 0) + /* + * Not a real first volume in a container is created, pre_reservation is needed. + */ + pre_reservation = IMSM_RESERVED_SECTORS; - if (maxsize < reserve) - return 0; + if (e[extent_idx].size == 0) + /* + * extent_idx points to the metadata, post_reservation is allready done. + */ + post_reservation = 0; + free(e); - super->create_offset = ~((unsigned long long) 0); - if (start + reserve > super->create_offset) - return 0; /* start overflows create_offset */ - super->create_offset = start + reserve; + reservation_size = pre_reservation + post_reservation; + + if (free_size < reservation_size) { + dprintf("imsm: Reservation size is greater than free space.\n"); + return 0; + } - return maxsize - reserve; + super->create_offset = start + pre_reservation; + return free_size - reservation_size; } static int is_raid_level_supported(const struct imsm_orom *orom, int level, int raiddisks) -- cgit v1.2.3