md: return the allocated devices from md_alloc

Two callers of md_alloc want to use the newly allocated devices, so
return it instead of letting them find it cumbersomely after the
allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-and-tested-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index 344910b..91836e6 100644 (file)
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -125,7 +125,6 @@ static void __init md_setup_drive(struct md_setup_args *args)
        char *devname = args->device_names;
        dev_t devices[MD_SB_DISKS + 1], mdev;
        struct mdu_array_info_s ainfo = { };
-       struct block_device *bdev;
        struct mddev *mddev;
        int err = 0, i;
        char name[16];
@@ -169,25 +168,16 @@ static void __init md_setup_drive(struct md_setup_args *args)
 
        pr_info("md: Loading %s: %s\n", name, args->device_names);
 
-       md_alloc(mdev, name);
-       bdev = blkdev_get_by_dev(mdev, FMODE_READ, NULL);
-       if (IS_ERR(bdev)) {
-               pr_err("md: open failed - cannot start array %s\n", name);
+       mddev = md_alloc(mdev, name);
+       if (IS_ERR(mddev)) {
+               pr_err("md: md_alloc failed - cannot start array %s\n", name);
                return;
        }
 
-       err = -EIO;
-       if (WARN(bdev->bd_disk->fops != &md_fops,
-                       "Opening block device %x resulted in non-md device\n",
-                       mdev))
-               goto out_blkdev_put;
-
-       mddev = bdev->bd_disk->private_data;
-
        err = mddev_lock(mddev);
        if (err) {
                pr_err("md: failed to lock array %s\n", name);
-               goto out_blkdev_put;
+               goto out_mddev_put;
        }
 
        if (!list_empty(&mddev->disks) || mddev->raid_disks) {
@@ -231,8 +221,8 @@ static void __init md_setup_drive(struct md_setup_args *args)
                pr_warn("md: starting %s failed\n", name);
 out_unlock:
        mddev_unlock(mddev);
-out_blkdev_put:
-       blkdev_put(bdev, FMODE_READ);
+out_mddev_put:
+       mddev_put(mddev);
 }
 
 static int __init raid_setup(char *str)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5671160..6e82df2 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -635,7 +635,7 @@ static inline struct mddev *mddev_get(struct mddev *mddev)
 
 static void mddev_delayed_delete(struct work_struct *ws);
 
-static void mddev_put(struct mddev *mddev)
+void mddev_put(struct mddev *mddev)
 {
        if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
                return;
@@ -714,24 +714,6 @@ static dev_t mddev_alloc_unit(void)
        return dev;
 }
 
-#ifndef MODULE
-static struct mddev *mddev_find(dev_t unit)
-{
-       struct mddev *mddev;
-
-       if (MAJOR(unit) != MD_MAJOR)
-               unit &= ~((1 << MdpMinorShift) - 1);
-
-       spin_lock(&all_mddevs_lock);
-       mddev = mddev_find_locked(unit);
-       if (mddev && !mddev_get(mddev))
-               mddev = NULL;
-       spin_unlock(&all_mddevs_lock);
-
-       return mddev;
-}
-#endif
-
 static struct mddev *mddev_alloc(dev_t unit)
 {
        struct mddev *new;
@@ -5614,7 +5596,7 @@ int mddev_init_writes_pending(struct mddev *mddev)
 }
 EXPORT_SYMBOL_GPL(mddev_init_writes_pending);
 
-int md_alloc(dev_t dev, char *name)
+struct mddev *md_alloc(dev_t dev, char *name)
 {
        /*
         * If dev is zero, name is the name of a device to allocate with
@@ -5706,17 +5688,16 @@ int md_alloc(dev_t dev, char *name)
                 * different from a normal close on last release now.
                 */
                mddev->hold_active = 0;
-               goto done;
+               mutex_unlock(&disks_mutex);
+               mddev_put(mddev);
+               return ERR_PTR(error);
        }
 
        kobject_uevent(&mddev->kobj, KOBJ_ADD);
        mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
        mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
-
-done:
        mutex_unlock(&disks_mutex);
-       mddev_put(mddev);
-       return error;
+       return mddev;
 
 out_put_disk:
        put_disk(disk);
@@ -5724,7 +5705,17 @@ out_free_mddev:
        mddev_free(mddev);
 out_unlock:
        mutex_unlock(&disks_mutex);
-       return error;
+       return ERR_PTR(error);
+}
+
+static int md_alloc_and_put(dev_t dev, char *name)
+{
+       struct mddev *mddev = md_alloc(dev, name);
+
+       if (IS_ERR(mddev))
+               return PTR_ERR(mddev);
+       mddev_put(mddev);
+       return 0;
 }
 
 static void md_probe(dev_t dev)
@@ -5732,7 +5723,7 @@ static void md_probe(dev_t dev)
        if (MAJOR(dev) == MD_MAJOR && MINOR(dev) >= 512)
                return;
        if (create_on_open)
-               md_alloc(dev, NULL);
+               md_alloc_and_put(dev, NULL);
 }
 
 static int add_named_array(const char *val, const struct kernel_param *kp)
@@ -5754,12 +5745,12 @@ static int add_named_array(const char *val, const struct kernel_param *kp)
                return -E2BIG;
        strscpy(buf, val, len+1);
        if (strncmp(buf, "md_", 3) == 0)
-               return md_alloc(0, buf);
+               return md_alloc_and_put(0, buf);
        if (strncmp(buf, "md", 2) == 0 &&
            isdigit(buf[2]) &&
            kstrtoul(buf+2, 10, &devnum) == 0 &&
            devnum <= MINORMASK)
-               return md_alloc(MKDEV(MD_MAJOR, devnum), NULL);
+               return md_alloc_and_put(MKDEV(MD_MAJOR, devnum), NULL);
 
        return -EINVAL;
 }
@@ -6500,9 +6491,8 @@ static void autorun_devices(int part)
                        break;
                }
 
-               md_alloc(dev, NULL);
-               mddev = mddev_find(dev);
-               if (!mddev)
+               mddev = md_alloc(dev, NULL);
+               if (IS_ERR(mddev))
                        break;
 
                if (mddev_lock(mddev))

diff --git a/drivers/md/md.h b/drivers/md/md.h
index f6ab73c..b4e2d8b 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -767,7 +767,8 @@ extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev);
 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
 
 extern void mddev_init(struct mddev *mddev);
-int md_alloc(dev_t dev, char *name);
+struct mddev *md_alloc(dev_t dev, char *name);
+void mddev_put(struct mddev *mddev);
 extern int md_run(struct mddev *mddev);
 extern int md_start(struct mddev *mddev);
 extern void md_stop(struct mddev *mddev);