Suppress 'zfs_sb_create' memory warning

[zfs.git] / module / zfs / zvol.c

diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index ba26543..07bda6d 100644 (file)
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -46,8 +46,10 @@
 #include <sys/zvol.h>
 #include <linux/blkdev_compat.h>
 
+unsigned int zvol_inhibit_dev = 0;
 unsigned int zvol_major = ZVOL_MAJOR;
 unsigned int zvol_threads = 32;
+unsigned long zvol_max_discard_blocks = 16384;
 
 static taskq_t *zvol_taskq;
 static kmutex_t zvol_state_lock;
@@ -1241,7 +1243,9 @@ __zvol_create_minor(const char *name)
        blk_queue_physical_block_size(zv->zv_queue, zv->zv_volblocksize);
        blk_queue_io_opt(zv->zv_queue, zv->zv_volblocksize);
 #ifdef HAVE_BLK_QUEUE_DISCARD
-       blk_queue_max_discard_sectors(zv->zv_queue, UINT_MAX);
+       blk_queue_max_discard_sectors(zv->zv_queue,
+           (zvol_max_discard_blocks * zv->zv_volblocksize) >> 9);
+       blk_queue_discard_granularity(zv->zv_queue, zv->zv_volblocksize);
        queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zv->zv_queue);
 #endif
 #ifdef HAVE_BLK_QUEUE_NONROT
@@ -1341,6 +1345,9 @@ zvol_create_minors(const char *pool)
        spa_t *spa = NULL;
        int error = 0;
 
+       if (zvol_inhibit_dev)
+               return (0);
+
        mutex_enter(&zvol_state_lock);
        if (pool) {
                error = dmu_objset_find_spa(NULL, pool, zvol_create_minors_cb,
@@ -1370,6 +1377,9 @@ zvol_remove_minors(const char *pool)
        zvol_state_t *zv, *zv_next;
        char *str;
 
+       if (zvol_inhibit_dev)
+               return;
+
        str = kmem_zalloc(MAXNAMELEN, KM_SLEEP);
        if (pool) {
                (void) strncpy(str, pool, strlen(pool));
@@ -1431,8 +1441,14 @@ zvol_fini(void)
        list_destroy(&zvol_state_list);
 }
 
+module_param(zvol_inhibit_dev, uint, 0644);
+MODULE_PARM_DESC(zvol_inhibit_dev, "Do not create zvol device nodes");
+
 module_param(zvol_major, uint, 0444);
 MODULE_PARM_DESC(zvol_major, "Major number for zvol device");
 
 module_param(zvol_threads, uint, 0444);
 MODULE_PARM_DESC(zvol_threads, "Number of threads for zvol device");
+
+module_param(zvol_max_discard_blocks, ulong, 0444);
+MODULE_PARM_DESC(zvol_max_discard_blocks, "Max number of blocks to discard at once");