From 7522a260773038ff58c213da3e722d1752655237 Mon Sep 17 00:00:00 2001 From: LOLi Date: Fri, 21 Sep 2018 06:10:12 +0200 Subject: [PATCH] Add limits to spa_slop_shift tunable This change adds limits to the possible spa_slop_shift values set via the sysfs interface. Accepted values are from a minimum of 1 to a maximum of 31 (inclusive): these limits are based on the following values observed on a 128PB file-vdev test pool: spa_slop_shift=1, spa_get_slop_space=63.5PiB spa_slop_shift=2, spa_get_slop_space=31.8PiB spa_slop_shift=3, spa_get_slop_space=15.9PiB spa_slop_shift=4, spa_get_slop_space=7.9PiB spa_slop_shift=5, spa_get_slop_space=4PiB spa_slop_shift=6, spa_get_slop_space=2PiB ... spa_slop_shift=25, spa_get_slop_space=4GiB spa_slop_shift=26, spa_get_slop_space=2GiB spa_slop_shift=27, spa_get_slop_space=1016MiB spa_slop_shift=28, spa_get_slop_space=508MiB spa_slop_shift=29, spa_get_slop_space=254MiB spa_slop_shift=30, spa_get_slop_space=128MiB spa_slop_shift=31, spa_get_slop_space=128MiB spa_slop_shift=32, spa_get_slop_space=128MiB Reviewed-by: Richard Elling Reviewed-by: Brian Behlendorf Signed-off-by: loli10K Closes #7876 Closes #7900 --- module/zfs/spa_misc.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c index 2c500c010c..343b01dd6a 100644 --- a/module/zfs/spa_misc.c +++ b/module/zfs/spa_misc.c @@ -2553,6 +2553,26 @@ param_set_deadman_synctime(const char *val, zfs_kernel_param_t *kp) return (0); } +static int +param_set_slop_shift(const char *buf, zfs_kernel_param_t *kp) +{ + unsigned long val; + int error; + + error = kstrtoul(buf, 0, &val); + if (error) + return (SET_ERROR(error)); + + if (val < 1 || val > 31) + return (SET_ERROR(-EINVAL)); + + error = param_set_int(buf, kp); + if (error < 0) + return (SET_ERROR(error)); + + return (0); +} + /* Namespace manipulation */ EXPORT_SYMBOL(spa_lookup); EXPORT_SYMBOL(spa_add); @@ -2678,7 +2698,8 @@ module_param(spa_asize_inflation, int, 0644); MODULE_PARM_DESC(spa_asize_inflation, "SPA size estimate multiplication factor"); -module_param(spa_slop_shift, int, 0644); +module_param_call(spa_slop_shift, param_set_slop_shift, param_get_int, + &spa_slop_shift, 0644); MODULE_PARM_DESC(spa_slop_shift, "Reserved free space in pool"); module_param(zfs_ddt_data_is_special, int, 0644);