[Drbd-dev] [PATCH 11/16] drbd: Allow to change data-integrity-alg on the fly
Philipp Reisner
philipp.reisner at linbit.com
Wed Oct 5 11:37:59 CEST 2011
From: Andreas Gruenbacher <agruen at linbit.com>
The main purpose of this is to allow to turn data integrity checking on
and off on demand without causing interruptions.
Implemented by allocating tconn->peer_integrity_tfm only when receiving
a P_PROTOCOL message. l accesses to tconn->peer_integrity_tf happen in
worker context, and no further synchronization is necessary.
On the sender side, tconn->integrity_tfm is modified under
tconn->data.mutex, and a P_PROTOCOL message is sent whenever. All
accesses to tconn->integrity_tfm already happen under this mutex.
Signed-off-by: Philipp Reisner <philipp.reisner at linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg at linbit.com>
---
drivers/block/drbd/drbd_main.c | 4 +-
drivers/block/drbd/drbd_nl.c | 22 ++++++++------
drivers/block/drbd/drbd_receiver.c | 54 +++++++++++++++++------------------
3 files changed, 40 insertions(+), 40 deletions(-)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index bcdd66d..1ea12d4 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1433,8 +1433,8 @@ static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
struct p_data *dp, int data_size)
{
- data_size -= (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->peer_integrity_tfm) ?
- crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm) : 0;
+ if (mdev->tconn->peer_integrity_tfm)
+ data_size -= crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
_drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size),
dp->block_id);
}
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index fd97ffb..0bf74b1 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1824,7 +1824,6 @@ struct crypto {
struct crypto_hash *csums_tfm;
struct crypto_hash *cram_hmac_tfm;
struct crypto_hash *integrity_tfm;
- struct crypto_hash *peer_integrity_tfm;
void *int_dig_in;
void *int_dig_vv;
};
@@ -1863,10 +1862,6 @@ alloc_crypto(struct crypto *crypto, struct net_conf *new_conf)
ERR_INTEGRITY_ALG);
if (rv != NO_ERROR)
return rv;
- rv = alloc_hash(&crypto->peer_integrity_tfm, new_conf->integrity_alg,
- ERR_INTEGRITY_ALG);
- if (rv != NO_ERROR)
- return rv;
if (new_conf->cram_hmac_alg[0] != 0) {
snprintf(hmac_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)",
new_conf->cram_hmac_alg);
@@ -1893,7 +1888,6 @@ static void free_crypto(struct crypto *crypto)
kfree(crypto->int_dig_vv);
crypto_free_hash(crypto->cram_hmac_tfm);
crypto_free_hash(crypto->integrity_tfm);
- crypto_free_hash(crypto->peer_integrity_tfm);
crypto_free_hash(crypto->csums_tfm);
crypto_free_hash(crypto->verify_tfm);
}
@@ -1907,6 +1901,7 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
int ovr; /* online verify running */
int rsr; /* re-sync running */
struct crypto crypto = { };
+ bool change_integrity_alg;
retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_CONN);
if (!adm_ctx.reply_skb)
@@ -1938,6 +1933,7 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
conn_reconfig_start(tconn);
+ mutex_lock(&tconn->data.mutex);
mutex_lock(&tconn->net_conf_update);
old_conf = tconn->net_conf;
@@ -1976,6 +1972,9 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
goto fail;
}
+ change_integrity_alg = strcmp(old_conf->integrity_alg,
+ new_conf->integrity_alg);
+
retcode = alloc_crypto(&crypto, new_conf);
if (retcode != NO_ERROR)
goto fail;
@@ -1993,21 +1992,24 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
crypto.verify_tfm = NULL;
}
- /* FIXME can not assign these so bluntly while we have ongoing IO */
kfree(tconn->int_dig_in);
tconn->int_dig_in = crypto.int_dig_in;
kfree(tconn->int_dig_vv);
tconn->int_dig_vv = crypto.int_dig_vv;
crypto_free_hash(tconn->integrity_tfm);
tconn->integrity_tfm = crypto.integrity_tfm;
- crypto_free_hash(tconn->peer_integrity_tfm);
- tconn->peer_integrity_tfm = crypto.peer_integrity_tfm;
+ if (change_integrity_alg) {
+ /* Do this without trying to take tconn->data.mutex again. */
+ if (__drbd_send_protocol(tconn))
+ goto fail;
+ }
/* FIXME Changing cram_hmac while the connection is established is useless */
crypto_free_hash(tconn->cram_hmac_tfm);
tconn->cram_hmac_tfm = crypto.cram_hmac_tfm;
mutex_unlock(&tconn->net_conf_update);
+ mutex_unlock(&tconn->data.mutex);
synchronize_rcu();
kfree(old_conf);
@@ -2018,6 +2020,7 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
fail:
mutex_unlock(&tconn->net_conf_update);
+ mutex_unlock(&tconn->data.mutex);
free_crypto(&crypto);
kfree(new_conf);
done:
@@ -2126,7 +2129,6 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
tconn->int_dig_vv = crypto.int_dig_vv;
tconn->cram_hmac_tfm = crypto.cram_hmac_tfm;
tconn->integrity_tfm = crypto.integrity_tfm;
- tconn->peer_integrity_tfm = crypto.peer_integrity_tfm;
tconn->csums_tfm = crypto.csums_tfm;
tconn->verify_tfm = crypto.verify_tfm;
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 30b6556..9c8bcce 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1384,10 +1384,9 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
void *dig_vv = mdev->tconn->int_dig_vv;
unsigned long *data;
- dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->peer_integrity_tfm) ?
- crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm) : 0;
-
- if (dgs) {
+ dgs = 0;
+ if (mdev->tconn->peer_integrity_tfm) {
+ dgs = crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
/*
* FIXME: Receive the incoming digest into the receive buffer
* here, together with its struct p_data?
@@ -1395,10 +1394,9 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
if (err)
return NULL;
+ data_size -= dgs;
}
- data_size -= dgs;
-
if (!expect(data_size != 0))
return NULL;
if (!expect(IS_ALIGNED(data_size, 512)))
@@ -1491,17 +1489,15 @@ static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
void *dig_in = mdev->tconn->int_dig_in;
void *dig_vv = mdev->tconn->int_dig_vv;
- dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->peer_integrity_tfm) ?
- crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm) : 0;
-
- if (dgs) {
+ dgs = 0;
+ if (mdev->tconn->peer_integrity_tfm) {
+ dgs = crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
if (err)
return err;
+ data_size -= dgs;
}
- data_size -= dgs;
-
/* optimistically update recv_cnt. if receiving fails below,
* we disconnect anyways, and counters will be reset. */
mdev->recv_cnt += data_size>>9;
@@ -2997,7 +2993,6 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
struct p_protocol *p = pi->data;
int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
int p_want_lose, p_two_primaries, cf;
- char p_integrity_alg[SHARED_SECRET_MAX] = "";
struct net_conf *nc;
p_proto = be32_to_cpu(p->protocol);
@@ -3009,15 +3004,30 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
p_want_lose = cf & CF_WANT_LOSE;
if (tconn->agreed_pro_version >= 87) {
+ char integrity_alg[SHARED_SECRET_MAX];
+ struct crypto_hash *tfm = NULL;
int err;
- if (pi->size > sizeof(p_integrity_alg))
+ if (pi->size > sizeof(integrity_alg))
return -EIO;
- err = drbd_recv_all(tconn, p_integrity_alg, pi->size);
+ err = drbd_recv_all(tconn, integrity_alg, pi->size);
if (err)
return err;
+ integrity_alg[SHARED_SECRET_MAX-1] = 0;
- p_integrity_alg[SHARED_SECRET_MAX-1] = 0;
+ if (integrity_alg[0]) {
+ tfm = crypto_alloc_hash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
+ if (!tfm) {
+ conn_err(tconn, "peer data-integrity-alg %s not supported\n",
+ integrity_alg);
+ goto disconnect;
+ }
+ conn_info(tconn, "peer data-integrity-alg: %s\n", integrity_alg);
+ }
+
+ if (tconn->peer_integrity_tfm)
+ crypto_free_hash(tconn->peer_integrity_tfm);
+ tconn->peer_integrity_tfm = tfm;
}
clear_bit(CONN_DRY_RUN, &tconn->flags);
@@ -3058,20 +3068,8 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
goto disconnect_rcu_unlock;
}
- if (tconn->agreed_pro_version >= 87) {
- if (strcmp(p_integrity_alg, nc->integrity_alg)) {
- conn_err(tconn, "incompatible setting of the data-integrity-alg\n");
- goto disconnect;
- }
- }
-
rcu_read_unlock();
- if (tconn->agreed_pro_version >= 87) {
- conn_info(tconn, "data-integrity-alg: %s\n",
- nc->integrity_alg[0] ? nc->integrity_alg : (unsigned char *)"<not-used>");
- }
-
return 0;
disconnect_rcu_unlock:
--
1.7.4.1
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