On Mon, Sep 08, 2014 at 12:30:19PM -0400, Jeff Layton wrote:
> From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
>
> In order to allow knfsd's lock manager to lift its grace period early,
> we need to figure out whether all clients have finished reclaiming
> their state not. Unfortunately, the current code doesn't allow us to
> ascertain this. All we track for each client is a timestamp that tells
> us when the last "check" or "create" operation came in.
>
> We need to track the two timestamps separately. Add a new
> "reclaim_complete" column to the database that tells us when the last
> "create" operation came in. For now, we just insert "0" in that column
> but a later patch will make it so that we insert a real timestamp for
> v4.1+ client records.
If I understand correctly, then nfsdcltrack has a bug here: we shouldn't
be counting a 4.1 client as allowed to reclaim on the next boot until we
get the RECLAIM_COMPLETE, but nfsdcltrack is allowing a 4.1 client to
reclaim if all we got the previous boot was a reclaim open (a "check"
operation).
--b.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
> ---
> utils/nfsdcltrack/sqlite.c | 102 +++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 94 insertions(+), 8 deletions(-)
>
> diff --git a/utils/nfsdcltrack/sqlite.c b/utils/nfsdcltrack/sqlite.c
> index dde2f7ff8621..e260e81b1722 100644
> --- a/utils/nfsdcltrack/sqlite.c
> +++ b/utils/nfsdcltrack/sqlite.c
> @@ -29,7 +29,10 @@
> *
> * clients: an "id" column containing a BLOB with the long-form clientid as
> * sent by the client, a "time" column containing a timestamp (in
> - * epoch seconds) of when the record was last updated.
> + * epoch seconds) of when the record was last updated, and a
> + * "reclaim_complete" column containing a timestamp (in epoch seconds)
> + * of when the last "create" operation came in for v4.1+ clients.
> + * v4.0 clients should always have this set to 0.
> */
>
> #ifdef HAVE_CONFIG_H
> @@ -50,7 +53,7 @@
>
> #include "xlog.h"
>
> -#define CLTRACK_SQLITE_LATEST_SCHEMA_VERSION 1
> +#define CLTRACK_SQLITE_LATEST_SCHEMA_VERSION 2
>
> /* in milliseconds */
> #define CLTRACK_SQLITE_BUSY_TIMEOUT 10000
> @@ -120,6 +123,81 @@ out:
> return ret;
> }
>
> +static int
> +sqlite_maindb_update_v1_to_v2(void)
> +{
> + int ret, ret2;
> + char *err;
> +
> + /* begin transaction */
> + ret = sqlite3_exec(dbh, "BEGIN EXCLUSIVE TRANSACTION;", NULL, NULL,
> + &err);
> + if (ret != SQLITE_OK) {
> + xlog(L_ERROR, "Unable to begin transaction: %s", err);
> + goto rollback;
> + }
> +
> + /*
> + * Check schema version again. This time, under an exclusive
> + * transaction to guard against racing DB setup attempts
> + */
> + ret = sqlite_query_schema_version();
> + switch (ret) {
> + case 1:
> + /* Still at v1 -- do conversion */
> + break;
> + case CLTRACK_SQLITE_LATEST_SCHEMA_VERSION:
> + /* Someone else raced in and set it up */
> + ret = 0;
> + goto rollback;
> + default:
> + /* Something went wrong -- fail! */
> + ret = -EINVAL;
> + goto rollback;
> + }
> +
> + /* create v2 clients table */
> + ret = sqlite3_exec(dbh, "ALTER TABLE clients ADD COLUMN "
> + "reclaim_complete INTEGER;",
> + NULL, NULL, &err);
> + if (ret != SQLITE_OK) {
> + xlog(L_ERROR, "Unable to update clients table: %s", err);
> + goto rollback;
> + }
> +
> + ret = snprintf(buf, sizeof(buf), "UPDATE parameters SET value = %d "
> + "WHERE key = \"version\";",
> + CLTRACK_SQLITE_LATEST_SCHEMA_VERSION);
> + if (ret < 0) {
> + xlog(L_ERROR, "sprintf failed!");
> + goto rollback;
> + } else if ((size_t)ret >= sizeof(buf)) {
> + xlog(L_ERROR, "sprintf output too long! (%d chars)", ret);
> + ret = -EINVAL;
> + goto rollback;
> + }
> +
> + ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
> + if (ret != SQLITE_OK) {
> + xlog(L_ERROR, "Unable to update schema version: %s", err);
> + goto rollback;
> + }
> +
> + ret = sqlite3_exec(dbh, "COMMIT TRANSACTION;", NULL, NULL, &err);
> + if (ret != SQLITE_OK) {
> + xlog(L_ERROR, "Unable to commit transaction: %s", err);
> + goto rollback;
> + }
> +out:
> + sqlite3_free(err);
> + return ret;
> +rollback:
> + ret2 = sqlite3_exec(dbh, "ROLLBACK TRANSACTION;", NULL, NULL, &err);
> + if (ret2 != SQLITE_OK)
> + xlog(L_ERROR, "Unable to rollback transaction: %s", err);
> + goto out;
> +}
> +
> /*
> * Start an exclusive transaction and recheck the DB schema version. If it's
> * still zero (indicating a new database) then set it up. If that all works,
> @@ -127,9 +205,9 @@ out:
> * transaction. On any error, rollback the transaction.
> */
> int
> -sqlite_maindb_init_v1(void)
> +sqlite_maindb_init_v2(void)
> {
> - int ret;
> + int ret, ret2;
> char *err = NULL;
>
> /* Start a transaction */
> @@ -169,7 +247,7 @@ sqlite_maindb_init_v1(void)
>
> /* create the "clients" table */
> ret = sqlite3_exec(dbh, "CREATE TABLE clients (id BLOB PRIMARY KEY, "
> - "time INTEGER);",
> + "time INTEGER, reclaim_complete INTEGER);",
> NULL, NULL, &err);
> if (ret != SQLITE_OK) {
> xlog(L_ERROR, "Unable to create clients table: %s", err);
> @@ -207,7 +285,9 @@ out:
>
> rollback:
> /* Attempt to rollback the transaction */
> - sqlite3_exec(dbh, "ROLLBACK TRANSACTION;", NULL, NULL, &err);
> + ret2 = sqlite3_exec(dbh, "ROLLBACK TRANSACTION;", NULL, NULL, &err);
> + if (ret2 != SQLITE_OK)
> + xlog(L_ERROR, "Unable to rollback transaction: %s", err);
> goto out;
> }
>
> @@ -255,9 +335,15 @@ sqlite_prepare_dbh(const char *topdir)
> /* DB is already set up. Do nothing */
> ret = 0;
> break;
> + case 1:
> + /* Old DB -- update to new schema */
> + ret = sqlite_maindb_update_v1_to_v2();
> + if (ret)
> + goto out_close;
> + break;
> case 0:
> /* Query failed -- try to set up new DB */
> - ret = sqlite_maindb_init_v1();
> + ret = sqlite_maindb_init_v2();
> if (ret)
> goto out_close;
> break;
> @@ -289,7 +375,7 @@ sqlite_insert_client(const unsigned char *clname, const size_t namelen)
> sqlite3_stmt *stmt = NULL;
>
> ret = sqlite3_prepare_v2(dbh, "INSERT OR REPLACE INTO clients VALUES "
> - "(?, strftime('%s', 'now'));", -1,
> + "(?, strftime('%s', 'now'), 0);", -1,
> &stmt, NULL);
> if (ret != SQLITE_OK) {
> xlog(L_ERROR, "%s: insert statement prepare failed: %s",
> --
> 1.9.3
>
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
