diff options
| -rw-r--r-- | drivers/md/dm-hw-handler.h | 1 | ||||
| -rw-r--r-- | drivers/md/dm-mpath.c | 81 |
2 files changed, 68 insertions, 14 deletions
diff --git a/drivers/md/dm-hw-handler.h b/drivers/md/dm-hw-handler.h index e0832e6fcf36..46809dcb121a 100644 --- a/drivers/md/dm-hw-handler.h +++ b/drivers/md/dm-hw-handler.h @@ -58,5 +58,6 @@ unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio); #define MP_FAIL_PATH 1 #define MP_BYPASS_PG 2 #define MP_ERROR_IO 4 /* Don't retry this I/O */ +#define MP_RETRY 8 #endif diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 31056abca89d..dd5ad6310f54 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -75,6 +75,8 @@ struct multipath { unsigned queue_io; /* Must we queue all I/O? */ unsigned queue_if_no_path; /* Queue I/O if last path fails? */ unsigned saved_queue_if_no_path;/* Saved state during suspension */ + unsigned pg_init_retries; /* Number of times to retry pg_init */ + unsigned pg_init_count; /* Number of times pg_init called */ struct work_struct process_queued_ios; struct bio_list queued_ios; @@ -225,6 +227,8 @@ static void __switch_pg(struct multipath *m, struct pgpath *pgpath) m->pg_init_required = 0; m->queue_io = 0; } + + m->pg_init_count = 0; } static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg) @@ -424,6 +428,7 @@ static void process_queued_ios(struct work_struct *work) must_queue = 0; if (m->pg_init_required && !m->pg_init_in_progress) { + m->pg_init_count++; m->pg_init_required = 0; m->pg_init_in_progress = 1; init_required = 1; @@ -689,9 +694,11 @@ static int parse_features(struct arg_set *as, struct multipath *m) int r; unsigned argc; struct dm_target *ti = m->ti; + const char *param_name; static struct param _params[] = { - {0, 1, "invalid number of feature args"}, + {0, 3, "invalid number of feature args"}, + {1, 50, "pg_init_retries must be between 1 and 50"}, }; r = read_param(_params, shift(as), &argc, &ti->error); @@ -701,12 +708,28 @@ static int parse_features(struct arg_set *as, struct multipath *m) if (!argc) return 0; - if (!strnicmp(shift(as), MESG_STR("queue_if_no_path"))) - return queue_if_no_path(m, 1, 0); - else { + do { + param_name = shift(as); + argc--; + + if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { + r = queue_if_no_path(m, 1, 0); + continue; + } + + if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && + (argc >= 1)) { + r = read_param(_params + 1, shift(as), + &m->pg_init_retries, &ti->error); + argc--; + continue; + } + ti->error = "Unrecognised multipath feature request"; - return -EINVAL; - } + r = -EINVAL; + } while (argc && !r); + + return r; } static int multipath_ctr(struct dm_target *ti, unsigned int argc, @@ -976,6 +999,26 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) } /* + * Should we retry pg_init immediately? + */ +static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) +{ + unsigned long flags; + int limit_reached = 0; + + spin_lock_irqsave(&m->lock, flags); + + if (m->pg_init_count <= m->pg_init_retries) + m->pg_init_required = 1; + else + limit_reached = 1; + + spin_unlock_irqrestore(&m->lock, flags); + + return limit_reached; +} + +/* * pg_init must call this when it has completed its initialisation */ void dm_pg_init_complete(struct dm_path *path, unsigned err_flags) @@ -985,8 +1028,14 @@ void dm_pg_init_complete(struct dm_path *path, unsigned err_flags) struct multipath *m = pg->m; unsigned long flags; - /* We insist on failing the path if the PG is already bypassed. */ - if (err_flags && pg->bypassed) + /* + * If requested, retry pg_init until maximum number of retries exceeded. + * If retry not requested and PG already bypassed, always fail the path. + */ + if (err_flags & MP_RETRY) { + if (pg_init_limit_reached(m, pgpath)) + err_flags |= MP_FAIL_PATH; + } else if (err_flags && pg->bypassed) err_flags |= MP_FAIL_PATH; if (err_flags & MP_FAIL_PATH) @@ -996,7 +1045,7 @@ void dm_pg_init_complete(struct dm_path *path, unsigned err_flags) bypass_pg(m, pg, 1); spin_lock_irqsave(&m->lock, flags); - if (err_flags) { + if (err_flags & ~MP_RETRY) { m->current_pgpath = NULL; m->current_pg = NULL; } else if (!m->pg_init_required) @@ -1148,11 +1197,15 @@ static int multipath_status(struct dm_target *ti, status_type_t type, /* Features */ if (type == STATUSTYPE_INFO) - DMEMIT("1 %u ", m->queue_size); - else if (m->queue_if_no_path) - DMEMIT("1 queue_if_no_path "); - else - DMEMIT("0 "); + DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); + else { + DMEMIT("%u ", m->queue_if_no_path + + (m->pg_init_retries > 0) * 2); + if (m->queue_if_no_path) + DMEMIT("queue_if_no_path "); + if (m->pg_init_retries) + DMEMIT("pg_init_retries %u ", m->pg_init_retries); + } if (hwh->type && hwh->type->status) sz += hwh->type->status(hwh, type, result + sz, maxlen - sz); |