This patch updates the md driver and personalities to the new
module interfaces.
An owner field has been added to the struct mdk_personality_s.
This is initialized by each personality module. The md driver
now attempts to take a reference to the personality before calling
the personality's run routine. A pers_lock was added to protect
the setting, clearing and reading of pers[] entries. This protects
try_module_get() racing with unregister_md_personality().
I have tested each personality as a module.
--
Daniel McNeil <daniel@osdl.org>
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/arch/i386/kernel/i386_ksyms.c linux-2.5.65-md/arch/i386/kernel/i386_ksyms.c
--- linux-2.5.65/arch/i386/kernel/i386_ksyms.c Mon Mar 17 13:44:50 2003
+++ linux-2.5.65-md/arch/i386/kernel/i386_ksyms.c Wed Mar 19 11:27:53 2003
@@ -76,6 +76,7 @@ EXPORT_SYMBOL(xquad_portio);
#ifndef CONFIG_X86_WP_WORKS_OK
EXPORT_SYMBOL(__verify_write);
#endif
+EXPORT_SYMBOL(kernel_fpu_begin);
EXPORT_SYMBOL(dump_thread);
EXPORT_SYMBOL(dump_fpu);
EXPORT_SYMBOL(dump_extended_fpu);
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/linear.c linux-2.5.65-md/drivers/md/linear.c
--- linux-2.5.65/drivers/md/linear.c Mon Mar 17 13:44:04 2003
+++ linux-2.5.65-md/drivers/md/linear.c Wed Mar 19 14:43:10 2003
@@ -75,8 +75,6 @@ static int linear_run (mddev_t *mddev)
unsigned int curr_offset;
struct list_head *tmp;
- MOD_INC_USE_COUNT;
-
conf = kmalloc (sizeof (*conf), GFP_KERNEL);
if (!conf)
goto out;
@@ -163,7 +161,6 @@ static int linear_run (mddev_t *mddev)
out:
if (conf)
kfree(conf);
- MOD_DEC_USE_COUNT;
return 1;
}
@@ -174,8 +171,6 @@ static int linear_stop (mddev_t *mddev)
kfree(conf->hash_table);
kfree(conf);
- MOD_DEC_USE_COUNT;
-
return 0;
}
@@ -241,6 +236,7 @@ static mdk_personality_t linear_personal
.run = linear_run,
.stop = linear_stop,
.status = linear_status,
+ .owner = THIS_MODULE
};
static int __init linear_init (void)
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/md.c linux-2.5.65-md/drivers/md/md.c
--- linux-2.5.65/drivers/md/md.c Mon Mar 17 13:43:50 2003
+++ linux-2.5.65-md/drivers/md/md.c Tue Mar 18 17:25:02 2003
@@ -63,6 +63,12 @@
static void autostart_arrays (void);
#endif
+/*
+ * pers_lock protects the setting, clearing and reading of pers[] entries.
+ * This protects try_module_get() racing with unregister_md_personality().
+ */
+static spinlock_t pers_lock = SPIN_LOCK_UNLOCKED;
+
static mdk_personality_t *pers[MAX_PERSONALITY];
/*
@@ -182,7 +188,6 @@ static void mddev_put(mddev_t *mddev)
list_del(&mddev->all_mddevs);
mddev_map[mdidx(mddev)] = NULL;
kfree(mddev);
- MOD_DEC_USE_COUNT;
}
spin_unlock(&all_mddevs_lock);
}
@@ -204,7 +209,6 @@ static mddev_t * mddev_find(int unit)
mddev_map[unit] = new;
list_add(&new->all_mddevs, &all_mddevs);
spin_unlock(&all_mddevs_lock);
- MOD_INC_USE_COUNT;
return new;
}
spin_unlock(&all_mddevs_lock);
@@ -1605,6 +1609,7 @@ static int do_md_run(mddev_t * mddev)
struct list_head *tmp;
mdk_rdev_t *rdev;
struct gendisk *disk;
+ mdk_personality_t *per;
if (list_empty(&mddev->disks)) {
MD_BUG();
@@ -1664,23 +1669,29 @@ static int do_md_run(mddev_t * mddev)
return -EINVAL;
}
- if (!pers[pnum])
- {
#ifdef CONFIG_KMOD
+ if (!pers[pnum]) {
char module_name[80];
sprintf (module_name, "md-personality-%d", pnum);
request_module (module_name);
- if (!pers[pnum])
+ }
#endif
- {
- printk(KERN_ERR "md: personality %d is not loaded!\n",
- pnum);
+ /*
+ * Get a module reference for the personality.
+ */
+ spin_lock(&pers_lock);
+ per = pers[pnum];
+ if (per == 0 || !try_module_get(per->owner)) {
+ spin_unlock(&pers_lock);
+ printk(KERN_ERR "md: personality %d is not loaded!\n", pnum);
return -EINVAL;
- }
}
+ spin_unlock(&pers_lock);
- if (device_size_calculation(mddev))
+ if (device_size_calculation(mddev)) {
+ module_put(per->owner); /* drop ref on personality */
return -EINVAL;
+ }
/*
* Drop all container device buffers, from now on
@@ -1709,9 +1720,11 @@ static int do_md_run(mddev_t * mddev)
md_probe(mdidx(mddev), NULL, NULL);
disk = disks[mdidx(mddev)];
- if (!disk)
+ if (!disk) {
+ module_put(per->owner); /* drop ref on personality */
return -ENOMEM;
- mddev->pers = pers[pnum];
+ }
+ mddev->pers = per;
blk_queue_make_request(&mddev->queue, mddev->pers->make_request);
printk("%s: setting max_sectors to %d, segment boundary to %d\n",
@@ -1724,6 +1737,7 @@ static int do_md_run(mddev_t * mddev)
err = mddev->pers->run(mddev);
if (err) {
+ module_put(per->owner); /* drop ref on personality */
printk(KERN_ERR "md: pers->run() failed ...\n");
mddev->pers = NULL;
return -EINVAL;
@@ -1826,6 +1840,10 @@ static int do_md_stop(mddev_t * mddev, i
set_disk_ro(disk, 1);
goto out;
}
+ /*
+ * Drop module reference to personality.
+ */
+ module_put(mddev->pers->owner);
mddev->pers = NULL;
if (mddev->ro)
mddev->ro = 0;
@@ -3040,10 +3058,12 @@ static int md_seq_show(struct seq_file *
if (v == (void*)1) {
seq_printf(seq, "Personalities : ");
+ spin_lock(&pers_lock);
for (i = 0; i < MAX_PERSONALITY; i++)
if (pers[i])
seq_printf(seq, "[%s] ", pers[i]->name);
+ spin_unlock(&pers_lock);
seq_printf(seq, "\n");
return 0;
}
@@ -3127,12 +3147,15 @@ int register_md_personality(int pnum, md
return -EINVAL;
}
+ spin_lock(&pers_lock);
if (pers[pnum]) {
+ spin_unlock(&pers_lock);
MD_BUG();
return -EBUSY;
}
pers[pnum] = p;
+ spin_unlock(&pers_lock);
printk(KERN_INFO "md: %s personality registered as nr %d\n", p->name, pnum);
return 0;
}
@@ -3145,7 +3168,9 @@ int unregister_md_personality(int pnum)
}
printk(KERN_INFO "md: %s personality unregistered\n", pers[pnum]->name);
+ spin_lock(&pers_lock);
pers[pnum] = NULL;
+ spin_unlock(&pers_lock);
return 0;
}
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/multipath.c linux-2.5.65-md/drivers/md/multipath.c
--- linux-2.5.65/drivers/md/multipath.c Mon Mar 17 13:44:05 2003
+++ linux-2.5.65-md/drivers/md/multipath.c Tue Mar 18 17:27:28 2003
@@ -416,8 +416,6 @@ static int multipath_run (mddev_t *mddev
mdk_rdev_t *rdev;
struct list_head *tmp;
- MOD_INC_USE_COUNT;
-
if (mddev->level != LEVEL_MULTIPATH) {
printk(INVALID_LEVEL, mdidx(mddev), mddev->level);
goto out;
@@ -491,7 +489,6 @@ out_free_conf:
kfree(conf);
mddev->private = NULL;
out:
- MOD_DEC_USE_COUNT;
return -EIO;
}
@@ -515,7 +512,6 @@ static int multipath_stop (mddev_t *mdde
mempool_destroy(conf->pool);
kfree(conf);
mddev->private = NULL;
- MOD_DEC_USE_COUNT;
return 0;
}
@@ -529,6 +525,7 @@ static mdk_personality_t multipath_perso
.error_handler = multipath_error,
.hot_add_disk = multipath_add_disk,
.hot_remove_disk= multipath_remove_disk,
+ .owner = THIS_MODULE
};
static int __init multipath_init (void)
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/raid0.c linux-2.5.65-md/drivers/md/raid0.c
--- linux-2.5.65/drivers/md/raid0.c Mon Mar 17 13:44:07 2003
+++ linux-2.5.65-md/drivers/md/raid0.c Tue Mar 18 17:28:22 2003
@@ -191,8 +191,6 @@ static int raid0_run (mddev_t *mddev)
s64 size;
raid0_conf_t *conf;
- MOD_INC_USE_COUNT;
-
conf = vmalloc(sizeof (raid0_conf_t));
if (!conf)
goto out;
@@ -267,7 +265,6 @@ out_free_conf:
vfree(conf);
mddev->private = NULL;
out:
- MOD_DEC_USE_COUNT;
return 1;
}
@@ -282,7 +279,6 @@ static int raid0_stop (mddev_t *mddev)
vfree (conf);
mddev->private = NULL;
- MOD_DEC_USE_COUNT;
return 0;
}
@@ -415,6 +411,7 @@ static mdk_personality_t raid0_personali
.run = raid0_run,
.stop = raid0_stop,
.status = raid0_status,
+ .owner = THIS_MODULE
};
static int __init raid0_init (void)
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/raid1.c linux-2.5.65-md/drivers/md/raid1.c
--- linux-2.5.65/drivers/md/raid1.c Mon Mar 17 13:44:07 2003
+++ linux-2.5.65-md/drivers/md/raid1.c Tue Mar 18 17:29:10 2003
@@ -1109,8 +1109,6 @@ static int run(mddev_t *mddev)
mdk_rdev_t *rdev;
struct list_head *tmp;
- MOD_INC_USE_COUNT;
-
if (mddev->level != 1) {
printk(INVALID_LEVEL, mdidx(mddev), mddev->level);
goto out;
@@ -1206,7 +1204,6 @@ out_free_conf:
kfree(conf);
mddev->private = NULL;
out:
- MOD_DEC_USE_COUNT;
return -EIO;
}
@@ -1220,7 +1217,6 @@ static int stop(mddev_t *mddev)
mempool_destroy(conf->r1bio_pool);
kfree(conf);
mddev->private = NULL;
- MOD_DEC_USE_COUNT;
return 0;
}
@@ -1236,6 +1232,7 @@ static mdk_personality_t raid1_personali
.hot_remove_disk= raid1_remove_disk,
.spare_active = raid1_spare_active,
.sync_request = sync_request,
+ .owner = THIS_MODULE
};
static int __init raid_init(void)
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/drivers/md/raid5.c linux-2.5.65-md/drivers/md/raid5.c
--- linux-2.5.65/drivers/md/raid5.c Mon Mar 17 13:43:45 2003
+++ linux-2.5.65-md/drivers/md/raid5.c Tue Mar 18 17:29:45 2003
@@ -1410,11 +1410,8 @@ static int run (mddev_t *mddev)
struct disk_info *disk;
struct list_head *tmp;
- MOD_INC_USE_COUNT;
-
if (mddev->level != 5 && mddev->level != 4) {
printk("raid5: md%d: raid level not set to 4/5 (%d)\n", mdidx(mddev), mddev->level);
- MOD_DEC_USE_COUNT;
return -EIO;
}
@@ -1524,7 +1521,6 @@ abort:
}
mddev->private = NULL;
printk(KERN_ALERT "raid5: failed to run raid set md%d\n", mdidx(mddev));
- MOD_DEC_USE_COUNT;
return -EIO;
}
@@ -1540,7 +1536,6 @@ static int stop (mddev_t *mddev)
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
kfree(conf);
mddev->private = NULL;
- MOD_DEC_USE_COUNT;
return 0;
}
@@ -1702,6 +1697,7 @@ static mdk_personality_t raid5_personali
.hot_remove_disk= raid5_remove_disk,
.spare_active = raid5_spare_active,
.sync_request = sync_request,
+ .owner = THIS_MODULE
};
static int __init raid5_init (void)
diff -rupN -X /home/daniel/dontdiff linux-2.5.65/include/linux/raid/md_k.h linux-2.5.65-md/include/linux/raid/md_k.h
--- linux-2.5.65/include/linux/raid/md_k.h Mon Mar 17 13:43:39 2003
+++ linux-2.5.65-md/include/linux/raid/md_k.h Tue Mar 18 17:04:30 2003
@@ -266,6 +266,7 @@ struct mdk_personality_s
int (*hot_remove_disk) (mddev_t *mddev, int number);
int (*spare_active) (mddev_t *mddev);
int (*sync_request)(mddev_t *mddev, sector_t sector_nr, int go_faster);
+ struct module *owner;
};
