From c57094a6e1ed5dd2d6401f79b8e6da34dd28f959 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 19 Jul 2022 11:18:16 +0200
Subject: [PATCH] md: fix error handling in md_alloc
Git-commit: c57094a6e1ed5dd2d6401f79b8e6da34dd28f959
Patch-mainline: v6.0-rc1
References: jsc#PED-2766
Error handling in md_alloc is a mess. Untangle it to just free the mddev
directly before add_disk is called and thus the gendisk is globally
visible. After that clear the hold flag and let the mddev_put take care
of cleaning up the mddev through the usual mechanisms.
(Coly Li: rebased for Linux v5.14 based SUSE kernel)
Fixes: 5e55e2f5fc95 ("[PATCH] md: convert compile time warnings into runtime warnings")
Fixes: 9be68dd7ac0e ("md: add error handling support for add_disk()")
Fixes: 7ad1069166c0 ("md: properly unwind when failing to add the kobject in md_alloc")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/md.c | 46 +++++++++++++++++++++++++++++++++-------------
1 file changed, 33 insertions(+), 13 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -790,6 +790,15 @@ out_free_new:
return ERR_PTR(error);
}
+static void mddev_free(struct mddev *mddev)
+{
+ spin_lock(&all_mddevs_lock);
+ list_del(&mddev->all_mddevs);
+ spin_unlock(&all_mddevs_lock);
+
+ kfree(mddev);
+}
+
static const struct attribute_group md_redundancy_group;
void mddev_unlock(struct mddev *mddev)
@@ -5661,8 +5670,8 @@ int md_alloc(dev_t dev, char *name)
mutex_lock(&disks_mutex);
mddev = mddev_alloc(dev);
if (IS_ERR(mddev)) {
- mutex_unlock(&disks_mutex);
- return PTR_ERR(mddev);
+ error = PTR_ERR(mddev);
+ goto out_unlock;
}
partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
@@ -5680,7 +5689,7 @@ int md_alloc(dev_t dev, char *name)
strcmp(mddev2->gendisk->disk_name, name) == 0) {
spin_unlock(&all_mddevs_lock);
error = -EEXIST;
- goto out_unlock_disks_mutex;
+ goto out_free_mddev;
}
spin_unlock(&all_mddevs_lock);
}
@@ -5693,7 +5702,7 @@ int md_alloc(dev_t dev, char *name)
error = -ENOMEM;
disk = blk_alloc_disk(NUMA_NO_NODE);
if (!disk)
- goto out_unlock_disks_mutex;
+ goto out_free_mddev;
disk->major = MAJOR(mddev->unit);
disk->first_minor = unit << shift;
@@ -5714,26 +5723,37 @@ int md_alloc(dev_t dev, char *name)
mddev->gendisk = disk;
error = add_disk(disk);
if (error)
- goto out_cleanup_disk;
+ goto out_put_disk;
kobject_init(&mddev->kobj, &md_ktype);
error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
- if (error)
- goto out_del_gendisk;
+ if (error) {
+ /*
+ * The disk is already live at this point. Clear the hold flag
+ * and let mddev_put take care of the deletion, as it isn't any
+ * different from a normal close on last release now.
+ */
+ mddev->hold_active = 0;
+ goto done;
+ }
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");
- goto out_unlock_disks_mutex;
-out_del_gendisk:
- del_gendisk(disk);
-out_cleanup_disk:
- blk_cleanup_disk(disk);
-out_unlock_disks_mutex:
+done:
mutex_unlock(&disks_mutex);
mddev_put(mddev);
return error;
+
+out_put_disk:
+ blk_cleanup_queue(disk->queue);
+ put_disk(disk);
+out_free_mddev:
+ mddev_free(mddev);
+out_unlock:
+ mutex_unlock(&disks_mutex);
+ return error;
}
static void md_probe(dev_t dev)