[lvm-devel] [PATCH] Calculate mirror log size instead of hardcoding 1 extent size.
Milan Broz
mbroz at redhat.com
Fri Dec 19 11:18:06 UTC 2008
Calculate mirror log size instead of hardcoding 1 extent size.
It fails for 1k PE now.
Patch adds log_region_size into allocation habdle struct
and use it in _alloc_parallel_area() for proper log size calculation
instead of hardcoded 1 extent - which can fail.
Reproducer for incorrect log size calculation:
DEV=/dev/sd[bcd]
pvcreate $DEV
vgcreate -s 1k vg_test $DEV
lvcreate -m1 -L 12M -n mirr vg_test
https://bugzilla.redhat.com/show_bug.cgi?id=477040
(note that without kernel patch from -mm for log size check
it will freeze - see bz https://bugzilla.redhat.com/show_bug.cgi?id=471565)
The log size calculation is mostly copied from kernel code.
The change in _for_each_pv() is tricky, we have no region_size information
there, but log_lv should be already configured - so it can use le_count.
(I am not sue if this code is correct anyway, but cannot found
path where it is wrong.)
Signed-off-by: Milan Broz <mbroz at redhat.com>
---
lib/metadata/lv_alloc.h | 2 +-
lib/metadata/lv_manip.c | 37 ++++++++++++++++++++++++++++++++-----
lib/metadata/metadata.h | 13 ++++++++++++-
lib/metadata/mirror.c | 6 +++---
4 files changed, 48 insertions(+), 10 deletions(-)
Index: LVM2/lib/metadata/metadata.h
===================================================================
--- LVM2.orig/lib/metadata/metadata.h 2008-12-09 12:00:32.000000000 +0100
+++ LVM2/lib/metadata/metadata.h 2008-12-19 09:53:05.000000000 +0100
@@ -34,7 +34,18 @@
//#define STRIPE_SIZE_LIMIT ((UINT_MAX >> 2) + 1)
//#define PV_MIN_SIZE ( 512L * 1024L >> SECTOR_SHIFT) /* 512 KB in sectors */
//#define MAX_RESTRICTED_LVS 255 /* Used by FMT_RESTRICTED_LVIDS */
-#define MIRROR_LOG_SIZE 1 /* Extents */
+#define MIRROR_LOG_OFFSET 2 /* sectors */
+
+/*
+ * Ceiling(n / sz)
+ */
+#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
+
+/*
+ * Ceiling(n / size) * size
+ */
+#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
+
/* Various flags */
/* Note that the bits no longer necessarily correspond to LVM1 disk format */
Index: LVM2/lib/metadata/lv_manip.c
===================================================================
--- LVM2.orig/lib/metadata/lv_manip.c 2008-12-09 12:00:32.000000000 +0100
+++ LVM2/lib/metadata/lv_manip.c 2008-12-19 12:00:05.000000000 +0100
@@ -516,6 +516,7 @@ struct alloc_handle {
uint32_t area_count; /* Number of parallel areas */
uint32_t area_multiple; /* seg->len = area_len * area_multiple */
uint32_t log_count; /* Number of parallel 1-extent logs */
+ uint32_t log_region_size; /* region size for log device */
uint32_t total_area_len; /* Total number of parallel extents */
struct dm_list *parallel_areas; /* PVs to avoid */
@@ -543,6 +544,7 @@ static struct alloc_handle *_alloc_init(
uint32_t mirrors,
uint32_t stripes,
uint32_t log_count,
+ uint32_t log_region_size,
struct dm_list *parallel_areas)
{
struct alloc_handle *ah;
@@ -582,6 +584,7 @@ static struct alloc_handle *_alloc_init(
ah->area_count = area_count;
ah->log_count = log_count;
+ ah->log_region_size = log_region_size;
ah->alloc = alloc;
ah->area_multiple = calc_area_multiple(segtype, area_count);
@@ -704,6 +707,28 @@ static int _setup_alloced_segments(struc
}
/*
+ * Returns log device size in extents, algorithm from kernel code
+ */
+#define BYTE_SHIFT 3
+static uint32_t mirror_log_extents(uint32_t region_size, uint32_t pe_size, uint32_t area_len)
+{
+ size_t area_size, bitset_size, log_size, region_count;
+
+ area_size = area_len * pe_size;
+ region_count = dm_div_up(area_size, region_size);
+
+ /* Work out how many "unsigned long"s we need to hold the bitset. */
+ bitset_size = dm_round_up(region_count, sizeof(uint32_t) << BYTE_SHIFT);
+ bitset_size >>= BYTE_SHIFT;
+
+ /* Log device holds both header and bitset. */
+ log_size = dm_round_up((MIRROR_LOG_OFFSET << SECTOR_SHIFT) + bitset_size, 1 << SECTOR_SHIFT);
+ log_size >>= SECTOR_SHIFT;
+
+ return dm_div_up(log_size, pe_size);
+}
+
+/*
* This function takes a list of pv_areas and adds them to allocated_areas.
* If the complete area is not needed then it gets split.
* The part used is removed from the pv_map so it can't be allocated twice.
@@ -745,7 +770,9 @@ static int _alloc_parallel_area(struct a
if (log_area) {
ah->log_area.pv = log_area->map->pv;
ah->log_area.pe = log_area->start;
- ah->log_area.len = MIRROR_LOG_SIZE; /* FIXME Calculate & check this */
+ ah->log_area.len = mirror_log_extents(ah->log_region_size,
+ pv_pe_size(log_area->map->pv),
+ area_len);
consume_pv_area(log_area, ah->log_area.len);
}
@@ -817,7 +844,7 @@ static int _for_each_pv(struct cmd_conte
/* FIXME only_single_area_segments used as workaround to skip log LV - needs new param? */
if (!only_single_area_segments && seg_is_mirrored(seg) && seg->log_lv) {
- if (!(r = _for_each_pv(cmd, seg->log_lv, 0, MIRROR_LOG_SIZE,
+ if (!(r = _for_each_pv(cmd, seg->log_lv, 0, seg->log_lv->le_count?:1,
NULL, 0, 0, 0, only_single_area_segments,
fn, data)))
stack;
@@ -1256,7 +1283,7 @@ struct alloc_handle *allocate_extents(st
const struct segment_type *segtype,
uint32_t stripes,
uint32_t mirrors, uint32_t log_count,
- uint32_t extents,
+ uint32_t log_region_size, uint32_t extents,
struct dm_list *allocatable_pvs,
alloc_policy_t alloc,
struct dm_list *parallel_areas)
@@ -1282,7 +1309,7 @@ struct alloc_handle *allocate_extents(st
alloc = vg->alloc;
if (!(ah = _alloc_init(vg->cmd, vg->cmd->mem, segtype, alloc, mirrors,
- stripes, log_count, parallel_areas)))
+ stripes, log_count, log_region_size, parallel_areas)))
return_NULL;
if (!segtype_is_virtual(segtype) &&
@@ -1577,7 +1604,7 @@ int lv_extend(struct logical_volume *lv,
if (segtype_is_virtual(segtype))
return lv_add_virtual_segment(lv, status, extents, segtype);
- if (!(ah = allocate_extents(lv->vg, lv, segtype, stripes, mirrors, 0,
+ if (!(ah = allocate_extents(lv->vg, lv, segtype, stripes, mirrors, 0, 0,
extents, allocatable_pvs, alloc, NULL)))
return_0;
Index: LVM2/lib/metadata/lv_alloc.h
===================================================================
--- LVM2.orig/lib/metadata/lv_alloc.h 2008-12-18 22:55:22.000000000 +0100
+++ LVM2/lib/metadata/lv_alloc.h 2008-12-18 22:55:58.000000000 +0100
@@ -47,7 +47,7 @@ struct alloc_handle *allocate_extents(st
const struct segment_type *segtype,
uint32_t stripes,
uint32_t mirrors, uint32_t log_count,
- uint32_t extents,
+ uint32_t log_region_size, uint32_t extents,
struct dm_list *allocatable_pvs,
alloc_policy_t alloc,
struct dm_list *parallel_areas);
Index: LVM2/lib/metadata/mirror.c
===================================================================
--- LVM2.orig/lib/metadata/mirror.c 2008-12-18 22:52:27.000000000 +0100
+++ LVM2/lib/metadata/mirror.c 2008-12-18 22:54:53.000000000 +0100
@@ -1171,7 +1171,7 @@ int add_mirrors_to_segments(struct cmd_c
lv->le_count,
region_size);
- if (!(ah = allocate_extents(lv->vg, NULL, segtype, 1, mirrors, 0,
+ if (!(ah = allocate_extents(lv->vg, NULL, segtype, 1, mirrors, 0, 0,
lv->le_count, allocatable_pvs, alloc,
parallel_areas))) {
log_error("Unable to allocate mirror extents for %s.", lv->name);
@@ -1388,7 +1388,7 @@ int add_mirror_log(struct cmd_context *c
/* allocate destination extents */
ah = allocate_extents(lv->vg, NULL, segtype,
- 0, 0, log_count, 0,
+ 0, 0, log_count, region_size, 0,
allocatable_pvs, alloc, parallel_areas);
if (!ah) {
log_error("Unable to allocate extents for mirror log.");
@@ -1443,7 +1443,7 @@ int add_mirror_images(struct cmd_context
return_0;
ah = allocate_extents(lv->vg, NULL, segtype,
- stripes, mirrors, log_count, lv->le_count,
+ stripes, mirrors, log_count, region_size, lv->le_count,
allocatable_pvs, alloc, parallel_areas);
if (!ah) {
log_error("Unable to allocate extents for mirror(s).");
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