diff options
| -rw-r--r-- | drivers/block/drbd/drbd_nl.c | 47 | ||||
| -rw-r--r-- | include/linux/drbd_limits.h | 11 |
2 files changed, 43 insertions, 15 deletions
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index bcf900bcd142..42fda4ae2f87 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1141,15 +1141,32 @@ static bool should_set_defaults(struct genl_info *info) return 0 != (flags & DRBD_GENL_F_SET_DEFAULTS); } -static void enforce_disk_conf_limits(struct disk_conf *dc) +static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev) { - if (dc->al_extents < DRBD_AL_EXTENTS_MIN) - dc->al_extents = DRBD_AL_EXTENTS_MIN; - if (dc->al_extents > DRBD_AL_EXTENTS_MAX) - dc->al_extents = DRBD_AL_EXTENTS_MAX; + /* This is limited by 16 bit "slot" numbers, + * and by available on-disk context storage. + * + * Also (u16)~0 is special (denotes a "free" extent). + * + * One transaction occupies one 4kB on-disk block, + * we have n such blocks in the on disk ring buffer, + * the "current" transaction may fail (n-1), + * and there is 919 slot numbers context information per transaction. + * + * 72 transaction blocks amounts to more than 2**16 context slots, + * so cap there first. + */ + const unsigned int max_al_nr = DRBD_AL_EXTENTS_MAX; + const unsigned int sufficient_on_disk = + (max_al_nr + AL_CONTEXT_PER_TRANSACTION -1) + /AL_CONTEXT_PER_TRANSACTION; - if (dc->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX) - dc->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX; + unsigned int al_size_4k = bdev->md.al_size_4k; + + if (al_size_4k > sufficient_on_disk) + return max_al_nr; + + return (al_size_4k - 1) * AL_CONTEXT_PER_TRANSACTION; } int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info) @@ -1196,7 +1213,13 @@ int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info) if (!expect(new_disk_conf->resync_rate >= 1)) new_disk_conf->resync_rate = 1; - enforce_disk_conf_limits(new_disk_conf); + if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN) + new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN; + if (new_disk_conf->al_extents > drbd_al_extents_max(mdev->ldev)) + new_disk_conf->al_extents = drbd_al_extents_max(mdev->ldev); + + if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX) + new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX; fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ; if (fifo_size != mdev->rs_plan_s->size) { @@ -1344,7 +1367,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) goto fail; } - enforce_disk_conf_limits(new_disk_conf); + if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX) + new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX; new_plan = fifo_alloc((new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ); if (!new_plan) { @@ -1419,6 +1443,11 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) if (retcode != NO_ERROR) goto fail; + if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN) + new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN; + if (new_disk_conf->al_extents > drbd_al_extents_max(nbc)) + new_disk_conf->al_extents = drbd_al_extents_max(nbc); + if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) { dev_err(DEV, "max capacity %llu smaller than disk size %llu\n", (unsigned long long) drbd_get_max_capacity(nbc), diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h index 1fa19c5f5e64..1fedf2b17cc8 100644 --- a/include/linux/drbd_limits.h +++ b/include/linux/drbd_limits.h @@ -126,13 +126,12 @@ #define DRBD_RESYNC_RATE_DEF 250 #define DRBD_RESYNC_RATE_SCALE 'k' /* kilobytes */ - /* less than 7 would hit performance unnecessarily. - * 919 slots context information per transaction, - * 32k activity log, 4k transaction size, - * one transaction in flight: - * 919 * 7 = 6433 */ + /* less than 7 would hit performance unnecessarily. */ #define DRBD_AL_EXTENTS_MIN 7 -#define DRBD_AL_EXTENTS_MAX 6433 + /* we use u16 as "slot number", (u16)~0 is "FREE". + * If you use >= 292 kB on-disk ring buffer, + * this is the maximum you can use: */ +#define DRBD_AL_EXTENTS_MAX 0xfffe #define DRBD_AL_EXTENTS_DEF 1237 #define DRBD_AL_EXTENTS_SCALE '1' |