On Tue, Jul 14 2020, Christoph Hellwig wrote:

> Move the loop over the possible arrays into the caller to remove a level
> of indentation for the whole function.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Song Liu <song@kernel.org>

Nice

Reviewed-by: NeilBrown <neilb@suse.de>

Thanks,
NeilBrown

> ---
>  drivers/md/md-autodetect.c | 203 ++++++++++++++++++-------------------
>  1 file changed, 101 insertions(+), 102 deletions(-)
>
> diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
> index 6bc9b734eee6ff..a43a8f1580584c 100644
> --- a/drivers/md/md-autodetect.c
> +++ b/drivers/md/md-autodetect.c
> @@ -27,7 +27,7 @@ static int __initdata raid_noautodetect=1;
>  #endif
>  static int __initdata raid_autopart;
>  
> -static struct {
> +static struct md_setup_args {
>  	int minor;
>  	int partitioned;
>  	int level;
> @@ -126,122 +126,117 @@ static inline int create_dev(char *name, dev_t dev)
>  	return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
>  }
>  
> -static void __init md_setup_drive(void)
> +static void __init md_setup_drive(struct md_setup_args *args)
>  {
> -	int minor, i, ent, partitioned;
> +	int minor, i, partitioned;
>  	dev_t dev;
>  	dev_t devices[MD_SB_DISKS+1];
> +	int fd;
> +	int err = 0;
> +	char *devname;
> +	mdu_disk_info_t dinfo;
> +	char name[16];
>  
> -	for (ent = 0; ent < md_setup_ents ; ent++) {
> -		int fd;
> -		int err = 0;
> -		char *devname;
> -		mdu_disk_info_t dinfo;
> -		char name[16];
> +	minor = args->minor;
> +	partitioned = args->partitioned;
> +	devname = args->device_names;
>  
> -		minor = md_setup_args[ent].minor;
> -		partitioned = md_setup_args[ent].partitioned;
> -		devname = md_setup_args[ent].device_names;
> +	sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
> +	if (partitioned)
> +		dev = MKDEV(mdp_major, minor << MdpMinorShift);
> +	else
> +		dev = MKDEV(MD_MAJOR, minor);
> +	create_dev(name, dev);
> +	for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
> +		struct kstat stat;
> +		char *p;
> +		char comp_name[64];
>  
> -		sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
> -		if (partitioned)
> -			dev = MKDEV(mdp_major, minor << MdpMinorShift);
> -		else
> -			dev = MKDEV(MD_MAJOR, minor);
> -		create_dev(name, dev);
> -		for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
> -			struct kstat stat;
> -			char *p;
> -			char comp_name[64];
> +		p = strchr(devname, ',');
> +		if (p)
> +			*p++ = 0;
>  
> -			p = strchr(devname, ',');
> -			if (p)
> -				*p++ = 0;
> +		dev = name_to_dev_t(devname);
> +		if (strncmp(devname, "/dev/", 5) == 0)
> +			devname += 5;
> +		snprintf(comp_name, 63, "/dev/%s", devname);
> +		if (vfs_stat(comp_name, &stat) == 0 && S_ISBLK(stat.mode))
> +			dev = new_decode_dev(stat.rdev);
> +		if (!dev) {
> +			printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
> +			break;
> +		}
>  
> -			dev = name_to_dev_t(devname);
> -			if (strncmp(devname, "/dev/", 5) == 0)
> -				devname += 5;
> -			snprintf(comp_name, 63, "/dev/%s", devname);
> -			if (vfs_stat(comp_name, &stat) == 0 &&
> -			    S_ISBLK(stat.mode))
> -				dev = new_decode_dev(stat.rdev);
> -			if (!dev) {
> -				printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
> -				break;
> -			}
> +		devices[i] = dev;
> +		devname = p;
> +	}
> +	devices[i] = 0;
>  
> -			devices[i] = dev;
> +	if (!i)
> +		return;
>  
> -			devname = p;
> -		}
> -		devices[i] = 0;
> +	printk(KERN_INFO "md: Loading md%s%d: %s\n",
> +		partitioned ? "_d" : "", minor,
> +		args->device_names);
>  
> -		if (!i)
> -			continue;
> +	fd = ksys_open(name, 0, 0);
> +	if (fd < 0) {
> +		printk(KERN_ERR "md: open failed - cannot start "
> +				"array %s\n", name);
> +		return;
> +	}
> +	if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
> +		printk(KERN_WARNING
> +		       "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
> +		       minor);
> +		ksys_close(fd);
> +		return;
> +	}
>  
> -		printk(KERN_INFO "md: Loading md%s%d: %s\n",
> -			partitioned ? "_d" : "", minor,
> -			md_setup_args[ent].device_names);
> +	if (args->level != LEVEL_NONE) {
> +		/* non-persistent */
> +		mdu_array_info_t ainfo;
> +		ainfo.level = args->level;
> +		ainfo.size = 0;
> +		ainfo.nr_disks =0;
> +		ainfo.raid_disks =0;
> +		while (devices[ainfo.raid_disks])
> +			ainfo.raid_disks++;
> +		ainfo.md_minor =minor;
> +		ainfo.not_persistent = 1;
>  
> -		fd = ksys_open(name, 0, 0);
> -		if (fd < 0) {
> -			printk(KERN_ERR "md: open failed - cannot start "
> -					"array %s\n", name);
> -			continue;
> -		}
> -		if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
> -			printk(KERN_WARNING
> -			       "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
> -			       minor);
> -			ksys_close(fd);
> -			continue;
> +		ainfo.state = (1 << MD_SB_CLEAN);
> +		ainfo.layout = 0;
> +		ainfo.chunk_size = args->chunk;
> +		err = ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
> +		for (i = 0; !err && i <= MD_SB_DISKS; i++) {
> +			dev = devices[i];
> +			if (!dev)
> +				break;
> +			dinfo.number = i;
> +			dinfo.raid_disk = i;
> +			dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
> +			dinfo.major = MAJOR(dev);
> +			dinfo.minor = MINOR(dev);
> +			err = ksys_ioctl(fd, ADD_NEW_DISK,
> +					 (long)&dinfo);
>  		}
> -
> -		if (md_setup_args[ent].level != LEVEL_NONE) {
> -			/* non-persistent */
> -			mdu_array_info_t ainfo;
> -			ainfo.level = md_setup_args[ent].level;
> -			ainfo.size = 0;
> -			ainfo.nr_disks =0;
> -			ainfo.raid_disks =0;
> -			while (devices[ainfo.raid_disks])
> -				ainfo.raid_disks++;
> -			ainfo.md_minor =minor;
> -			ainfo.not_persistent = 1;
> -
> -			ainfo.state = (1 << MD_SB_CLEAN);
> -			ainfo.layout = 0;
> -			ainfo.chunk_size = md_setup_args[ent].chunk;
> -			err = ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
> -			for (i = 0; !err && i <= MD_SB_DISKS; i++) {
> -				dev = devices[i];
> -				if (!dev)
> -					break;
> -				dinfo.number = i;
> -				dinfo.raid_disk = i;
> -				dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
> -				dinfo.major = MAJOR(dev);
> -				dinfo.minor = MINOR(dev);
> -				err = ksys_ioctl(fd, ADD_NEW_DISK,
> -						 (long)&dinfo);
> -			}
> -		} else {
> -			/* persistent */
> -			for (i = 0; i <= MD_SB_DISKS; i++) {
> -				dev = devices[i];
> -				if (!dev)
> -					break;
> -				dinfo.major = MAJOR(dev);
> -				dinfo.minor = MINOR(dev);
> -				ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
> -			}
> +	} else {
> +		/* persistent */
> +		for (i = 0; i <= MD_SB_DISKS; i++) {
> +			dev = devices[i];
> +			if (!dev)
> +				break;
> +			dinfo.major = MAJOR(dev);
> +			dinfo.minor = MINOR(dev);
> +			ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
>  		}
> -		if (!err)
> -			err = ksys_ioctl(fd, RUN_ARRAY, 0);
> -		if (err)
> -			printk(KERN_WARNING "md: starting md%d failed\n", minor);
> -		ksys_close(fd);
>  	}
> +	if (!err)
> +		err = ksys_ioctl(fd, RUN_ARRAY, 0);
> +	if (err)
> +		printk(KERN_WARNING "md: starting md%d failed\n", minor);
> +	ksys_close(fd);
>  }
>  
>  static int __init raid_setup(char *str)
> @@ -289,11 +284,15 @@ static void __init autodetect_raid(void)
>  
>  void __init md_run_setup(void)
>  {
> +	int ent;
> +
>  	create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));
>  
>  	if (raid_noautodetect)
>  		printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
>  	else
>  		autodetect_raid();
> -	md_setup_drive();
> +
> +	for (ent = 0; ent < md_setup_ents; ent++)
> +		md_setup_drive(&md_setup_args[ent]);
>  }
> -- 
> 2.27.0