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authorJoe Thornber <ejt@redhat.com>2021-12-10 16:36:06 +0300
committerMike Snitzer <snitzer@redhat.com>2022-01-04 21:48:12 +0300
commitc671ffa55d8b0dd3ed0a329e15dfe9c58f7483cd (patch)
tree86d7355d83e7dc00881d8535d66383bb05f6899a /drivers/md
parente36649b6483c68f9d4978785083972e72adbdbd2 (diff)
downloadlinux-c671ffa55d8b0dd3ed0a329e15dfe9c58f7483cd.tar.xz
dm btree remove: change a bunch of BUG_ON() calls to proper errors
Abuse of BUG_ON() is never appropriate, best to propagate errors to fail gracefully (rather than take the entire system down). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/persistent-data/dm-btree-remove.c173
1 files changed, 122 insertions, 51 deletions
diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c
index cb670f16e98e..4ead31e0d8ce 100644
--- a/drivers/md/persistent-data/dm-btree-remove.c
+++ b/drivers/md/persistent-data/dm-btree-remove.c
@@ -9,6 +9,9 @@
#include "dm-transaction-manager.h"
#include <linux/export.h>
+#include <linux/device-mapper.h>
+
+#define DM_MSG_PREFIX "btree"
/*
* Removing an entry from a btree
@@ -79,15 +82,23 @@ static void node_shift(struct btree_node *n, int shift)
}
}
-static void node_copy(struct btree_node *left, struct btree_node *right, int shift)
+static int node_copy(struct btree_node *left, struct btree_node *right, int shift)
{
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t value_size = le32_to_cpu(left->header.value_size);
- BUG_ON(value_size != le32_to_cpu(right->header.value_size));
+ if (value_size != le32_to_cpu(right->header.value_size)) {
+ DMERR("mismatched value size");
+ return -EILSEQ;
+ }
if (shift < 0) {
shift = -shift;
- BUG_ON(nr_left + shift > le32_to_cpu(left->header.max_entries));
+
+ if (nr_left + shift > le32_to_cpu(left->header.max_entries)) {
+ DMERR("bad shift");
+ return -EINVAL;
+ }
+
memcpy(key_ptr(left, nr_left),
key_ptr(right, 0),
shift * sizeof(__le64));
@@ -95,7 +106,11 @@ static void node_copy(struct btree_node *left, struct btree_node *right, int shi
value_ptr(right, 0),
shift * value_size);
} else {
- BUG_ON(shift > le32_to_cpu(right->header.max_entries));
+ if (shift > le32_to_cpu(right->header.max_entries)) {
+ DMERR("bad shift");
+ return -EINVAL;
+ }
+
memcpy(key_ptr(right, 0),
key_ptr(left, nr_left - shift),
shift * sizeof(__le64));
@@ -103,6 +118,7 @@ static void node_copy(struct btree_node *left, struct btree_node *right, int shi
value_ptr(left, nr_left - shift),
shift * value_size);
}
+ return 0;
}
/*
@@ -170,35 +186,54 @@ static void exit_child(struct dm_btree_info *info, struct child *c)
dm_tm_unlock(info->tm, c->block);
}
-static void shift(struct btree_node *left, struct btree_node *right, int count)
+static int shift(struct btree_node *left, struct btree_node *right, int count)
{
+ int r;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
uint32_t r_max_entries = le32_to_cpu(right->header.max_entries);
- BUG_ON(max_entries != r_max_entries);
- BUG_ON(nr_left - count > max_entries);
- BUG_ON(nr_right + count > max_entries);
+ if (max_entries != r_max_entries) {
+ DMERR("node max_entries mismatch");
+ return -EILSEQ;
+ }
+
+ if (nr_left - count > max_entries) {
+ DMERR("node shift out of bounds");
+ return -EINVAL;
+ }
+
+ if (nr_right + count > max_entries) {
+ DMERR("node shift out of bounds");
+ return -EINVAL;
+ }
if (!count)
- return;
+ return 0;
if (count > 0) {
node_shift(right, count);
- node_copy(left, right, count);
+ r = node_copy(left, right, count);
+ if (r)
+ return r;
} else {
- node_copy(left, right, count);
+ r = node_copy(left, right, count);
+ if (r)
+ return r;
node_shift(right, count);
}
left->header.nr_entries = cpu_to_le32(nr_left - count);
right->header.nr_entries = cpu_to_le32(nr_right + count);
+
+ return 0;
}
-static void __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
- struct child *l, struct child *r)
+static int __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
+ struct child *l, struct child *r)
{
+ int ret;
struct btree_node *left = l->n;
struct btree_node *right = r->n;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
@@ -229,9 +264,12 @@ static void __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
* Rebalance.
*/
unsigned target_left = (nr_left + nr_right) / 2;
- shift(left, right, nr_left - target_left);
+ ret = shift(left, right, nr_left - target_left);
+ if (ret)
+ return ret;
*key_ptr(parent, r->index) = right->keys[0];
}
+ return 0;
}
static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
@@ -253,12 +291,12 @@ static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
return r;
}
- __rebalance2(info, parent, &left, &right);
+ r = __rebalance2(info, parent, &left, &right);
exit_child(info, &left);
exit_child(info, &right);
- return 0;
+ return r;
}
/*
@@ -266,21 +304,30 @@ static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
* in right, then rebalance2. This wastes some cpu, but I want something
* simple atm.
*/
-static void delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
- struct child *l, struct child *c, struct child *r,
- struct btree_node *left, struct btree_node *center, struct btree_node *right,
- uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
+static int delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
+ struct child *l, struct child *c, struct child *r,
+ struct btree_node *left, struct btree_node *center, struct btree_node *right,
+ uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned shift = min(max_entries - nr_left, nr_center);
- BUG_ON(nr_left + shift > max_entries);
+ if (nr_left + shift > max_entries) {
+ DMERR("node shift out of bounds");
+ return -EINVAL;
+ }
+
node_copy(left, center, -shift);
left->header.nr_entries = cpu_to_le32(nr_left + shift);
if (shift != nr_center) {
shift = nr_center - shift;
- BUG_ON((nr_right + shift) > max_entries);
+
+ if ((nr_right + shift) > max_entries) {
+ DMERR("node shift out of bounds");
+ return -EINVAL;
+ }
+
node_shift(right, shift);
node_copy(center, right, shift);
right->header.nr_entries = cpu_to_le32(nr_right + shift);
@@ -291,18 +338,18 @@ static void delete_center_node(struct dm_btree_info *info, struct btree_node *pa
r->index--;
dm_tm_dec(info->tm, dm_block_location(c->block));
- __rebalance2(info, parent, l, r);
+ return __rebalance2(info, parent, l, r);
}
/*
* Redistributes entries among 3 sibling nodes.
*/
-static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
- struct child *l, struct child *c, struct child *r,
- struct btree_node *left, struct btree_node *center, struct btree_node *right,
- uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
+static int redistribute3(struct dm_btree_info *info, struct btree_node *parent,
+ struct child *l, struct child *c, struct child *r,
+ struct btree_node *left, struct btree_node *center, struct btree_node *right,
+ uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
- int s;
+ int s, ret;
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned total = nr_left + nr_center + nr_right;
unsigned target_right = total / 3;
@@ -317,35 +364,55 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
if (s < 0 && nr_center < -s) {
/* not enough in central node */
- shift(left, center, -nr_center);
+ ret = shift(left, center, -nr_center);
+ if (ret)
+ return ret;
+
s += nr_center;
- shift(left, right, s);
- nr_right += s;
- } else
- shift(left, center, s);
+ ret = shift(left, right, s);
+ if (ret)
+ return ret;
- shift(center, right, target_right - nr_right);
+ nr_right += s;
+ } else {
+ ret = shift(left, center, s);
+ if (ret)
+ return ret;
+ }
+ ret = shift(center, right, target_right - nr_right);
+ if (ret)
+ return ret;
} else {
s = target_right - nr_right;
if (s > 0 && nr_center < s) {
/* not enough in central node */
- shift(center, right, nr_center);
+ ret = shift(center, right, nr_center);
+ if (ret)
+ return ret;
s -= nr_center;
- shift(left, right, s);
+ ret = shift(left, right, s);
+ if (ret)
+ return ret;
nr_left -= s;
- } else
- shift(center, right, s);
+ } else {
+ ret = shift(center, right, s);
+ if (ret)
+ return ret;
+ }
- shift(left, center, nr_left - target_left);
+ ret = shift(left, center, nr_left - target_left);
+ if (ret)
+ return ret;
}
*key_ptr(parent, c->index) = center->keys[0];
*key_ptr(parent, r->index) = right->keys[0];
+ return 0;
}
-static void __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
- struct child *l, struct child *c, struct child *r)
+static int __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
+ struct child *l, struct child *c, struct child *r)
{
struct btree_node *left = l->n;
struct btree_node *center = c->n;
@@ -357,15 +424,19 @@ static void __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
unsigned threshold = merge_threshold(left) * 4 + 1;
- BUG_ON(left->header.max_entries != center->header.max_entries);
- BUG_ON(center->header.max_entries != right->header.max_entries);
+ if ((left->header.max_entries != center->header.max_entries) ||
+ (center->header.max_entries != right->header.max_entries)) {
+ DMERR("bad btree metadata, max_entries differ");
+ return -EILSEQ;
+ }
+
+ if ((nr_left + nr_center + nr_right) < threshold) {
+ return delete_center_node(info, parent, l, c, r, left, center, right,
+ nr_left, nr_center, nr_right);
+ }
- if ((nr_left + nr_center + nr_right) < threshold)
- delete_center_node(info, parent, l, c, r, left, center, right,
- nr_left, nr_center, nr_right);
- else
- redistribute3(info, parent, l, c, r, left, center, right,
- nr_left, nr_center, nr_right);
+ return redistribute3(info, parent, l, c, r, left, center, right,
+ nr_left, nr_center, nr_right);
}
static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
@@ -395,13 +466,13 @@ static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
return r;
}
- __rebalance3(info, parent, &left, &center, &right);
+ r = __rebalance3(info, parent, &left, &center, &right);
exit_child(info, &left);
exit_child(info, &center);
exit_child(info, &right);
- return 0;
+ return r;
}
static int rebalance_children(struct shadow_spine *s,