dm raid1: add handle_errors feature flag

This patch adds the ability to specify desired features in the mirror
constructor/mapping table.

The first feature of interest is "handle_errors".  Currently, mirroring will
ignore any I/O errors from the devices.  Subsequent patches will check for
this flag and handle the errors.  If flag/feature is not present, mirror will
do nothing - maintaining backwards compatibility.

Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jonathan E Brassow 2007-05-09 02:32:59 -07:00 committed by Linus Torvalds
parent 315dcc226f
commit a8e6afa236

View File

@ -22,6 +22,8 @@
#define DM_MSG_PREFIX "raid1"
#define DM_RAID1_HANDLE_ERRORS 0x01
static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
/*-----------------------------------------------------------------
@ -118,6 +120,7 @@ struct mirror_set {
struct list_head list;
struct region_hash rh;
struct kcopyd_client *kcopyd_client;
uint64_t features;
spinlock_t lock; /* protects the next two lists */
struct bio_list reads;
@ -1010,14 +1013,54 @@ static struct dirty_log *create_dirty_log(struct dm_target *ti,
return dl;
}
static int parse_features(struct mirror_set *ms, unsigned argc, char **argv,
unsigned *args_used)
{
unsigned num_features;
struct dm_target *ti = ms->ti;
*args_used = 0;
if (!argc)
return 0;
if (sscanf(argv[0], "%u", &num_features) != 1) {
ti->error = "Invalid number of features";
return -EINVAL;
}
argc--;
argv++;
(*args_used)++;
if (num_features > argc) {
ti->error = "Not enough arguments to support feature count";
return -EINVAL;
}
if (!strcmp("handle_errors", argv[0]))
ms->features |= DM_RAID1_HANDLE_ERRORS;
else {
ti->error = "Unrecognised feature requested";
return -EINVAL;
}
(*args_used)++;
return 0;
}
/*
* Construct a mirror mapping:
*
* log_type #log_params <log_params>
* #mirrors [mirror_path offset]{2,}
* [#features <features>]
*
* log_type is "core" or "disk"
* #log_params is between 1 and 3
*
* If present, features must be "handle_errors".
*/
#define DM_IO_PAGES 64
static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
@ -1043,8 +1086,8 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
argv++, argc--;
if (argc != nr_mirrors * 2) {
ti->error = "Wrong number of mirror arguments";
if (argc < nr_mirrors * 2) {
ti->error = "Too few mirror arguments";
dm_destroy_dirty_log(dl);
return -EINVAL;
}
@ -1077,6 +1120,21 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
INIT_WORK(&ms->kmirrord_work, do_mirror);
r = parse_features(ms, argc, argv, &args_used);
if (r) {
free_context(ms, ti, ms->nr_mirrors);
return r;
}
argv += args_used;
argc -= args_used;
if (argc) {
ti->error = "Too many mirror arguments";
free_context(ms, ti, ms->nr_mirrors);
return -EINVAL;
}
r = kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client);
if (r) {
destroy_workqueue(ms->kmirrord_wq);
@ -1230,6 +1288,9 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
for (m = 0; m < ms->nr_mirrors; m++)
DMEMIT(" %s %llu", ms->mirror[m].dev->name,
(unsigned long long)ms->mirror[m].offset);
if (ms->features & DM_RAID1_HANDLE_ERRORS)
DMEMIT(" 1 handle_errors");
}
return 0;