diff options
Diffstat (limited to 'drivers/md/bcache/super.c')
| -rw-r--r-- | drivers/md/bcache/super.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 61d3b63fa617..4dee119c3664 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -25,6 +25,9 @@ #include <linux/reboot.h> #include <linux/sysfs.h> +unsigned int bch_cutoff_writeback; +unsigned int bch_cutoff_writeback_sync; + static const char bcache_magic[] = { 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca, 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81 @@ -2420,6 +2423,32 @@ static void bcache_exit(void) mutex_destroy(&bch_register_lock); } +/* Check and fixup module parameters */ +static void check_module_parameters(void) +{ + if (bch_cutoff_writeback_sync == 0) + bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC; + else if (bch_cutoff_writeback_sync > CUTOFF_WRITEBACK_SYNC_MAX) { + pr_warn("set bch_cutoff_writeback_sync (%u) to max value %u", + bch_cutoff_writeback_sync, CUTOFF_WRITEBACK_SYNC_MAX); + bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC_MAX; + } + + if (bch_cutoff_writeback == 0) + bch_cutoff_writeback = CUTOFF_WRITEBACK; + else if (bch_cutoff_writeback > CUTOFF_WRITEBACK_MAX) { + pr_warn("set bch_cutoff_writeback (%u) to max value %u", + bch_cutoff_writeback, CUTOFF_WRITEBACK_MAX); + bch_cutoff_writeback = CUTOFF_WRITEBACK_MAX; + } + + if (bch_cutoff_writeback > bch_cutoff_writeback_sync) { + pr_warn("set bch_cutoff_writeback (%u) to %u", + bch_cutoff_writeback, bch_cutoff_writeback_sync); + bch_cutoff_writeback = bch_cutoff_writeback_sync; + } +} + static int __init bcache_init(void) { static const struct attribute *files[] = { @@ -2428,6 +2457,8 @@ static int __init bcache_init(void) NULL }; + check_module_parameters(); + mutex_init(&bch_register_lock); init_waitqueue_head(&unregister_wait); register_reboot_notifier(&reboot); @@ -2464,9 +2495,18 @@ err: return -ENOMEM; } +/* + * Module hooks + */ module_exit(bcache_exit); module_init(bcache_init); +module_param(bch_cutoff_writeback, uint, 0); +MODULE_PARM_DESC(bch_cutoff_writeback, "threshold to cutoff writeback"); + +module_param(bch_cutoff_writeback_sync, uint, 0); +MODULE_PARM_DESC(bch_cutoff_writeback_sync, "hard threshold to cutoff writeback"); + MODULE_DESCRIPTION("Bcache: a Linux block layer cache"); MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>"); MODULE_LICENSE("GPL"); |