4:20 p.m.
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teigland pushed a commit to branch testing
in repository sanlock.
commit 63768d8b96763a763a134b9c7d3362995158aa94
Author: David Teigland <teigland(a)redhat.com>
Date: Fri Nov 17 16:38:06 2017 -0600
sanlock: preserve dblock values when setting shared flag
steps for acquiring a shared lease:
1. acquire paxos lease
2. write shared flag into mode_block
3. release paxos lease
The mode_block follows the dblock, and when writing the
new mode_block, the dblock values were cleared.
If another host is running a paxos ballot for the same
lver (leader version) of the lease as was acquired in step 1,
then clearing the dblock values in step 2 can cause the
paxos ballot to miss the fact that the lease has already
been acquired for the given version, and the second host
will think that it also has acquired the lease with the same
version.
This is fixed by keeping the dblock values intact when
writing the mode_block in step 2.
---
src/direct.c | 3 ++-
src/paxos_lease.c | 5 ++++-
src/paxos_lease.h | 3 +++
src/resource.c | 58 +++++++++++++++++++++++++++++++++++++------------------
4 files changed, 48 insertions(+), 21 deletions(-)
diff --git a/src/direct.c b/src/direct.c
index d8bad50..3d4832a 100644
--- a/src/direct.c
+++ b/src/direct.c
@@ -80,6 +80,7 @@ static int do_paxos_action(int action, struct task *task, int
io_timeout, struct
{
struct token *token;
struct leader_record leader;
+ struct paxos_dblock dblock;
int disks_len, token_len;
int j, rv = 0;
@@ -123,7 +124,7 @@ static int do_paxos_action(int action, struct task *task, int
io_timeout, struct
token->host_id = local_host_id;
token->host_generation = local_host_generation;
- rv = paxos_lease_acquire(task, token, 0, leader_ret, 0, num_hosts);
+ rv = paxos_lease_acquire(task, token, 0, leader_ret, &dblock, 0, num_hosts);
break;
case ACT_RELEASE:
diff --git a/src/paxos_lease.c b/src/paxos_lease.c
index 3666e21..726056f 100644
--- a/src/paxos_lease.c
+++ b/src/paxos_lease.c
@@ -52,7 +52,7 @@ uint32_t leader_checksum(struct leader_record *lr)
return crc32c((uint32_t)~1, (uint8_t *)lr, LEADER_CHECKSUM_LEN);
}
-static uint32_t dblock_checksum(struct paxos_dblock *pd)
+uint32_t dblock_checksum(struct paxos_dblock *pd)
{
return crc32c((uint32_t)~1, (uint8_t *)pd, DBLOCK_CHECKSUM_LEN);
}
@@ -765,6 +765,7 @@ static int run_ballot(struct task *task, struct token *token, int
num_hosts,
(unsigned long long)next_lver, error);
}
+ memcpy(dblock_out, &dblock, sizeof(struct paxos_dblock));
return error;
}
@@ -1396,6 +1397,7 @@ int paxos_lease_acquire(struct task *task,
struct token *token,
uint32_t flags,
struct leader_record *leader_ret,
+ struct paxos_dblock *dblock_ret,
uint64_t acquire_lver,
int new_num_hosts)
{
@@ -1881,6 +1883,7 @@ int paxos_lease_acquire(struct task *task,
(unsigned long long)new_leader.timestamp);
memcpy(leader_ret, &new_leader, sizeof(struct leader_record));
+ memcpy(dblock_ret, &dblock, sizeof(struct paxos_dblock));
error = SANLK_OK;
out:
diff --git a/src/paxos_lease.h b/src/paxos_lease.h
index ec015dd..cce85ed 100644
--- a/src/paxos_lease.h
+++ b/src/paxos_lease.h
@@ -16,6 +16,8 @@
uint32_t leader_checksum(struct leader_record *lr);
+uint32_t dblock_checksum(struct paxos_dblock *pd);
+
int paxos_lease_leader_read(struct task *task,
struct token *token,
struct leader_record *leader_ret,
@@ -25,6 +27,7 @@ int paxos_lease_acquire(struct task *task,
struct token *token,
uint32_t flags,
struct leader_record *leader_ret,
+ struct paxos_dblock *dblock_ret,
uint64_t acquire_lver,
int new_num_hosts);
diff --git a/src/resource.c b/src/resource.c
index 584b66f..317fcb7 100644
--- a/src/resource.c
+++ b/src/resource.c
@@ -297,13 +297,16 @@ void check_mode_block(struct token *token, uint64_t next_lver, int
q, char *dblo
}
static int write_host_block(struct task *task, struct token *token,
- uint64_t host_id, uint64_t mb_gen, uint32_t mb_flags)
+ uint64_t host_id, uint64_t mb_gen, uint32_t mb_flags,
+ struct paxos_dblock *pd)
{
struct sync_disk *disk;
struct mode_block mb;
struct mode_block mb_end;
+ struct paxos_dblock pd_end;
char *iobuf, **p_iobuf;
uint64_t offset;
+ uint32_t checksum;
int num_disks = token->r.num_disks;
int iobuf_len, rv, d;
@@ -321,6 +324,20 @@ static int write_host_block(struct task *task, struct token *token,
memset(iobuf, 0, iobuf_len);
+ /*
+ * When writing our mode block, we need to keep our dblock
+ * values intact because other hosts may be running the
+ * paxos algorithm and these values need to remain intact
+ * for them to reach the correct result.
+ */
+ if (pd) {
+ paxos_dblock_out(pd, &pd_end);
+ checksum = dblock_checksum(&pd_end);
+ pd->checksum = checksum;
+ pd_end.checksum = cpu_to_le32(checksum);
+ memcpy(iobuf, (char *)&pd_end, sizeof(struct paxos_dblock));
+ }
+
if (mb_gen || mb_flags) {
memset(&mb, 0, sizeof(mb));
mb.flags = mb_flags;
@@ -350,7 +367,6 @@ static int write_host_block(struct task *task, struct token *token,
if (rv != SANLK_AIO_TIMEOUT)
free(iobuf);
return rv;
-
}
static int read_mode_block(struct task *task, struct token *token,
@@ -433,7 +449,7 @@ static int clear_dead_shared(struct task *task, struct token *token,
continue;
}
- rv = write_host_block(task, token, host_id, 0, 0);
+ rv = write_host_block(task, token, host_id, 0, 0, NULL);
if (rv < 0) {
log_errot(token, "clear_dead_shared host_id %llu write_host_block %d",
(unsigned long long)host_id, rv);
@@ -569,7 +585,8 @@ int res_get_lvb(struct sanlk_resource *res, char **lvb_out, int
*lvblen)
static int acquire_disk(struct task *task, struct token *token,
uint64_t acquire_lver, int new_num_hosts,
- int owner_nowait, struct leader_record *leader)
+ int owner_nowait, struct leader_record *leader,
+ struct paxos_dblock *dblock)
{
struct leader_record leader_tmp;
int rv;
@@ -586,8 +603,8 @@ static int acquire_disk(struct task *task, struct token *token,
memset(&leader_tmp, 0, sizeof(leader_tmp));
- rv = paxos_lease_acquire(task, token, flags, &leader_tmp, acquire_lver,
- new_num_hosts);
+ rv = paxos_lease_acquire(task, token, flags, &leader_tmp, dblock,
+ acquire_lver, new_num_hosts);
log_token(token, "acquire_disk rv %d lver %llu at %llu", rv,
(unsigned long long)leader_tmp.lver,
@@ -798,7 +815,7 @@ static int _release_token(struct task *task, struct token *token,
*/
if (r_flags & R_ERASE_ALL) {
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0) {
log_errot(token, "release_token erase all write_host_block %d", rv);
ret = rv;
@@ -828,7 +845,7 @@ static int _release_token(struct task *task, struct token *token,
(unsigned long long)lver, rv);
} else if (r_flags & R_UNDO_SHARED) {
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0) {
log_errot(token, "release_token undo shared write_host_block %d", rv);
ret = rv;
@@ -849,7 +866,7 @@ static int _release_token(struct task *task, struct token *token,
} else if (r_flags & R_SHARED) {
/* normal release of sh lease */
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0) {
log_errot(token, "release_token shared write_host_block %d", rv);
ret = rv;
@@ -879,7 +896,7 @@ static int _release_token(struct task *task, struct token *token,
}
/* Failure here is not a big deal and can be ignored. */
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0)
log_errot(token, "release_token write_host_block %d", rv);
@@ -1094,6 +1111,7 @@ static struct resource *new_resource(struct token *token)
static int convert_sh2ex_token(struct task *task, struct resource *r, struct token
*token)
{
struct leader_record leader;
+ struct paxos_dblock dblock;
int live_count = 0;
int retries;
int error;
@@ -1114,7 +1132,7 @@ static int convert_sh2ex_token(struct task *task, struct resource
*r, struct tok
token->flags |= T_WRITE_DBLOCK_MBLOCK_SH;
- rv = paxos_lease_acquire(task, token, 0, &leader, 0, 0);
+ rv = paxos_lease_acquire(task, token, 0, &leader, &dblock, 0, 0);
token->flags &= ~T_WRITE_DBLOCK_MBLOCK_SH;
@@ -1186,7 +1204,7 @@ static int convert_sh2ex_token(struct task *task, struct resource
*r, struct tok
}
do_mb:
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, &dblock);
if (rv < 0) {
log_errot(token, "convert_sh2ex write_host_block error %d", rv);
@@ -1259,7 +1277,8 @@ static int convert_ex2sh_token(struct task *task, struct resource
*r, struct tok
if (r->flags & R_LVB_WRITE_RELEASE)
write_lvb_block(task, r, token);
- rv = write_host_block(task, token, token->host_id, token->host_generation,
MBLOCK_SHARED);
+ /* FIXME: preserve dblock */
+ rv = write_host_block(task, token, token->host_id, token->host_generation,
MBLOCK_SHARED, NULL);
if (rv < 0) {
log_errot(token, "convert_ex2sh write_host_block error %d", rv);
return rv;
@@ -1382,6 +1401,7 @@ int acquire_token(struct task *task, struct token *token, uint32_t
cmd_flags,
char *killpath, char *killargs)
{
struct leader_record leader;
+ struct paxos_dblock dblock;
struct resource *r;
uint64_t acquire_lver = 0;
uint32_t new_num_hosts = 0;
@@ -1565,7 +1585,7 @@ int acquire_token(struct task *task, struct token *token, uint32_t
cmd_flags,
retry:
memset(&leader, 0, sizeof(struct leader_record));
- rv = acquire_disk(task, token, acquire_lver, new_num_hosts, owner_nowait, &leader);
+ rv = acquire_disk(task, token, acquire_lver, new_num_hosts, owner_nowait, &leader,
&dblock);
if (rv == SANLK_ACQUIRE_IDLIVE || rv == SANLK_ACQUIRE_OWNED || rv ==
SANLK_ACQUIRE_OTHER) {
/*
@@ -1631,7 +1651,7 @@ int acquire_token(struct task *task, struct token *token, uint32_t
cmd_flags,
*/
if (token->acquire_flags & SANLK_RES_SHARED) {
- rv = write_host_block(task, token, token->host_id, token->host_generation,
MBLOCK_SHARED);
+ rv = write_host_block(task, token, token->host_id, token->host_generation,
MBLOCK_SHARED, &dblock);
if (rv < 0) {
log_errot(token, "acquire_token sh write_host_block error %d", rv);
r->flags &= ~R_SHARED;
@@ -1990,7 +2010,7 @@ static void resource_thread_release(struct task *task, struct
resource *r, struc
log_token(token, "release async r_flags %x", r_flags);
if (r_flags & R_ERASE_ALL) {
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0)
log_errot(token, "release async erase all write_host_block %d", rv);
@@ -2015,7 +2035,7 @@ static void resource_thread_release(struct task *task, struct
resource *r, struc
(unsigned long long)r->leader.lver, rv);
} else if (r_flags & R_UNDO_SHARED) {
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0)
log_errot(token, "release async undo shared write_host_block %d", rv);
@@ -2032,7 +2052,7 @@ static void resource_thread_release(struct task *task, struct
resource *r, struc
} else if (r_flags & R_SHARED) {
/* normal release of sh lease */
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0)
log_errot(token, "release async shared write_host_block %d", rv);
@@ -2051,7 +2071,7 @@ static void resource_thread_release(struct task *task, struct
resource *r, struc
}
/* Failure here is not a big deal and can be ignored. */
- rv = write_host_block(task, token, token->host_id, 0, 0);
+ rv = write_host_block(task, token, token->host_id, 0, 0, NULL);
if (rv < 0)
log_errot(token, "release async write_host_block %d", rv);
--
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