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author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2014-06-07 01:28:53 -0500 |
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committer | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2015-02-23 09:59:06 -0600 |
commit | 601b515c5dcc00fa71148cd9d2405ea1f70bc9cd (patch) | |
tree | 3f798549738830d44d83a5f8cb547266b06b83de /drivers/md/md-cluster.c | |
parent | 4664680c389828928efc61ce3d2cf2c65ad35c97 (diff) | |
download | op-kernel-dev-601b515c5dcc00fa71148cd9d2405ea1f70bc9cd.zip op-kernel-dev-601b515c5dcc00fa71148cd9d2405ea1f70bc9cd.tar.gz |
Communication Framework: Sending functions
The sending part is split in two functions to make sure
atomicity of the operations, such as the MD superblock update.
Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Diffstat (limited to 'drivers/md/md-cluster.c')
-rw-r--r-- | drivers/md/md-cluster.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index 96734cd..9a4abe1 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -358,6 +358,93 @@ static void recv_daemon(struct md_thread *thread) dlm_unlock_sync(message_lockres); } +/* lock_comm() + * Takes the lock on the TOKEN lock resource so no other + * node can communicate while the operation is underway. + */ +static int lock_comm(struct md_cluster_info *cinfo) +{ + int error; + + error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX); + if (error) + pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n", + __func__, __LINE__, error); + return error; +} + +static void unlock_comm(struct md_cluster_info *cinfo) +{ + dlm_unlock_sync(cinfo->token_lockres); +} + +/* __sendmsg() + * This function performs the actual sending of the message. This function is + * usually called after performing the encompassing operation + * The function: + * 1. Grabs the message lockresource in EX mode + * 2. Copies the message to the message LVB + * 3. Downconverts message lockresource to CR + * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes + * and the other nodes read the message. The thread will wait here until all other + * nodes have released ack lock resource. + * 5. Downconvert ack lockresource to CR + */ +static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg) +{ + int error; + int slot = cinfo->slot_number - 1; + + cmsg->slot = cpu_to_le32(slot); + /*get EX on Message*/ + error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX); + if (error) { + pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error); + goto failed_message; + } + + memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg, + sizeof(struct cluster_msg)); + /*down-convert EX to CR on Message*/ + error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CR); + if (error) { + pr_err("md-cluster: failed to convert EX to CR on MESSAGE(%d)\n", + error); + goto failed_message; + } + + /*up-convert CR to EX on Ack*/ + error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX); + if (error) { + pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n", + error); + goto failed_ack; + } + + /*down-convert EX to CR on Ack*/ + error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR); + if (error) { + pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n", + error); + goto failed_ack; + } + +failed_ack: + dlm_unlock_sync(cinfo->message_lockres); +failed_message: + return error; +} + +static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg) +{ + int ret; + + lock_comm(cinfo); + ret = __sendmsg(cinfo, cmsg); + unlock_comm(cinfo); + return ret; +} + static int gather_all_resync_info(struct mddev *mddev, int total_slots) { struct md_cluster_info *cinfo = mddev->cluster_info; |