diff --git a/drivers/md/md.c b/drivers/md/md.c index 3b6fe3c9ad119eb94d8efd3eb28d07b08e8ea4f6..763e554f44c8ef88d401ae08df7928812e0b0de1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -723,6 +723,27 @@ static struct mddev *mddev_find_locked(dev_t unit) return NULL; } +/* find an unused unit number */ +static dev_t mddev_alloc_unit(void) +{ + static int next_minor = 512; + int start = next_minor; + bool is_free = 0; + dev_t dev = 0; + + while (!is_free) { + dev = MKDEV(MD_MAJOR, next_minor); + next_minor++; + if (next_minor > MINORMASK) + next_minor = 0; + if (next_minor == start) + return 0; /* Oh dear, all in use. */ + is_free = !mddev_find_locked(dev); + } + + return dev; +} + static struct mddev *mddev_find(dev_t unit) { struct mddev *mddev; @@ -739,73 +760,46 @@ static struct mddev *mddev_find(dev_t unit) return mddev; } -static struct mddev *mddev_find_or_alloc(dev_t unit) +static struct mddev *mddev_alloc(dev_t unit) { - struct mddev *mddev, *new = NULL; + struct mddev *new; + int error; if (unit && MAJOR(unit) != MD_MAJOR) - unit &= ~((1<all_mddevs, &all_mddevs); - spin_unlock(&all_mddevs_lock); - new->hold_active = UNTIL_IOCTL; - return new; - } - } else if (new) { - /* find an unused unit number */ - static int next_minor = 512; - int start = next_minor; - int is_free = 0; - int dev = 0; - while (!is_free) { - dev = MKDEV(MD_MAJOR, next_minor); - next_minor++; - if (next_minor > MINORMASK) - next_minor = 0; - if (next_minor == start) { - /* Oh dear, all in use. */ - spin_unlock(&all_mddevs_lock); - kfree(new); - return NULL; - } - - is_free = !mddev_find_locked(dev); - } - new->unit = dev; - new->md_minor = MINOR(dev); + error = -EEXIST; + if (mddev_find_locked(unit)) + goto out_free_new; + new->unit = unit; + if (MAJOR(unit) == MD_MAJOR) + new->md_minor = MINOR(unit); + else + new->md_minor = MINOR(unit) >> MdpMinorShift; + new->hold_active = UNTIL_IOCTL; + } else { + error = -ENODEV; + new->unit = mddev_alloc_unit(); + if (!new->unit) + goto out_free_new; + new->md_minor = MINOR(new->unit); new->hold_active = UNTIL_STOP; - list_add(&new->all_mddevs, &all_mddevs); - spin_unlock(&all_mddevs_lock); - return new; } - spin_unlock(&all_mddevs_lock); - new = kzalloc(sizeof(*new), GFP_KERNEL); - if (!new) - return NULL; - - new->unit = unit; - if (MAJOR(unit) == MD_MAJOR) - new->md_minor = MINOR(unit); - else - new->md_minor = MINOR(unit) >> MdpMinorShift; - - mddev_init(new); - - goto retry; + list_add(&new->all_mddevs, &all_mddevs); + spin_unlock(&all_mddevs_lock); + return new; +out_free_new: + spin_unlock(&all_mddevs_lock); + kfree(new); + return ERR_PTR(error); } static struct attribute_group md_redundancy_group; @@ -5727,30 +5721,30 @@ static int md_alloc(dev_t dev, char *name) * writing to /sys/module/md_mod/parameters/new_array. */ static DEFINE_MUTEX(disks_mutex); - struct mddev *mddev = mddev_find_or_alloc(dev); + struct mddev *mddev; struct gendisk *disk; int partitioned; int shift; int unit; - int error; + int error ; - if (!mddev) - return -ENODEV; - - partitioned = (MAJOR(mddev->unit) != MD_MAJOR); - shift = partitioned ? MdpMinorShift : 0; - unit = MINOR(mddev->unit) >> shift; - - /* wait for any previous instance of this device to be - * completely removed (mddev_delayed_delete). + /* + * Wait for any previous instance of this device to be completely + * removed (mddev_delayed_delete). */ flush_workqueue(md_misc_wq); flush_workqueue(md_rdev_misc_wq); mutex_lock(&disks_mutex); - error = -EEXIST; - if (mddev->gendisk) - goto abort; + mddev = mddev_alloc(dev); + if (IS_ERR(mddev)) { + mutex_unlock(&disks_mutex); + return PTR_ERR(mddev); + } + + partitioned = (MAJOR(mddev->unit) != MD_MAJOR); + shift = partitioned ? MdpMinorShift : 0; + unit = MINOR(mddev->unit) >> shift; if (name && !dev) { /* Need to ensure that 'name' is not a duplicate. @@ -5762,6 +5756,7 @@ static int md_alloc(dev_t dev, char *name) if (mddev2->gendisk && strcmp(mddev2->gendisk->disk_name, name) == 0) { spin_unlock(&all_mddevs_lock); + error = -EEXIST; goto abort; } spin_unlock(&all_mddevs_lock);