md: rewrite md_setup_drive to avoid ioctls

md_setup_drive knows it works with md devices, so it is rather pointless
to open a file descriptor and issue ioctls.  Just call directly into the
relevant low-level md routines after getting a handle to the device using
blkdev_get_by_dev instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: NeilBrown <neilb@suse.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index a43a8f1..14b6e86 100644 (file)
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -2,7 +2,6 @@
 #include <linux/kernel.h>
 #include <linux/blkdev.h>
 #include <linux/init.h>
-#include <linux/syscalls.h>
 #include <linux/mount.h>
 #include <linux/major.h>
 #include <linux/delay.h>
@@ -120,37 +119,29 @@ static int __init md_setup(char *str)
        return 1;
 }
 
-static inline int create_dev(char *name, dev_t dev)
-{
-       ksys_unlink(name);
-       return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
-}
-
 static void __init md_setup_drive(struct md_setup_args *args)
 {
-       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 *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];
 
-       minor = args->minor;
-       partitioned = args->partitioned;
-       devname = args->device_names;
+       if (args->partitioned) {
+               mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
+               sprintf(name, "md_d%d", args->minor);
+       } else {
+               mdev = MKDEV(MD_MAJOR, args->minor);
+               sprintf(name, "md%d", args->minor);
+       }
 
-       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];
+               dev_t dev;
 
                p = strchr(devname, ',');
                if (p)
@@ -163,7 +154,7 @@ static void __init md_setup_drive(struct md_setup_args *args)
                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);
+                       pr_warn("md: Unknown device name: %s\n", devname);
                        break;
                }
 
@@ -175,68 +166,71 @@ static void __init md_setup_drive(struct md_setup_args *args)
        if (!i)
                return;
 
-       printk(KERN_INFO "md: Loading md%s%d: %s\n",
-               partitioned ? "_d" : "", minor,
-               args->device_names);
+       pr_info("md: Loading %s: %s\n", name, args->device_names);
 
-       fd = ksys_open(name, 0, 0);
-       if (fd < 0) {
-               printk(KERN_ERR "md: open failed - cannot start "
-                               "array %s\n", 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);
                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;
+
+       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;
+       }
+
+       if (!list_empty(&mddev->disks) || mddev->raid_disks) {
+               pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
+                      name);
+               goto out_unlock;
        }
 
        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.md_minor = args->minor;
                ainfo.not_persistent = 1;
-
                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;
+               while (devices[ainfo.raid_disks])
+                       ainfo.raid_disks++;
+       }
+
+       err = md_set_array_info(mddev, &ainfo);
+
+       for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
+               struct mdu_disk_info_s dinfo = {
+                       .major  = MAJOR(devices[i]),
+                       .minor  = MINOR(devices[i]),
+               };
+
+               if (args->level != LEVEL_NONE) {
                        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);
+                       dinfo.state =
+                               (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
                }
+
+               md_add_new_disk(mddev, &dinfo);
        }
+
        if (!err)
-               err = ksys_ioctl(fd, RUN_ARRAY, 0);
+               err = do_md_run(mddev);
        if (err)
-               printk(KERN_WARNING "md: starting md%d failed\n", minor);
-       ksys_close(fd);
+               pr_warn("md: starting %s failed\n", name);
+out_unlock:
+       mddev_unlock(mddev);
+out_blkdev_put:
+       blkdev_put(bdev, FMODE_READ);
 }
 
 static int __init raid_setup(char *str)
@@ -286,8 +280,6 @@ 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

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6e9a48d..ee622b6 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -326,8 +326,6 @@ static struct ctl_table raid_root_table[] = {
        {  }
 };
 
-static const struct block_device_operations md_fops;
-
 static int start_readonly;
 
 /*
@@ -4368,7 +4366,6 @@ array_state_show(struct mddev *mddev, char *page)
 
 static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
-static int do_md_run(struct mddev *mddev);
 static int restart_array(struct mddev *mddev);
 
 static ssize_t
@@ -6015,7 +6012,7 @@ abort:
 }
 EXPORT_SYMBOL_GPL(md_run);
 
-static int do_md_run(struct mddev *mddev)
+int do_md_run(struct mddev *mddev)
 {
        int err;
 
@@ -6651,7 +6648,7 @@ static int get_disk_info(struct mddev *mddev, void __user * arg)
        return 0;
 }
 
-static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
+int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info)
 {
        char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
        struct md_rdev *rdev;
@@ -6697,7 +6694,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
        }
 
        /*
-        * add_new_disk can be used once the array is assembled
+        * md_add_new_disk can be used once the array is assembled
         * to add "hot spares".  They must already have a superblock
         * written
         */
@@ -6810,7 +6807,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
                return err;
        }
 
-       /* otherwise, add_new_disk is only allowed
+       /* otherwise, md_add_new_disk is only allowed
         * for major_version==0 superblocks
         */
        if (mddev->major_version != 0) {
@@ -7055,7 +7052,7 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
 }
 
 /*
- * set_array_info is used two different ways
+ * md_set_array_info is used two different ways
  * The original usage is when creating a new array.
  * In this usage, raid_disks is > 0 and it together with
  *  level, size, not_persistent,layout,chunksize determine the
@@ -7067,9 +7064,8 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
  *  The minor and patch _version numbers are also kept incase the
  *  super_block handler wishes to interpret them.
  */
-static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
+int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info)
 {
-
        if (info->raid_disks == 0) {
                /* just setting version number for superblock loading */
                if (info->major_version < 0 ||
@@ -7560,7 +7556,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                        err = -EBUSY;
                        goto unlock;
                }
-               err = set_array_info(mddev, &info);
+               err = md_set_array_info(mddev, &info);
                if (err) {
                        pr_warn("md: couldn't set array info. %d\n", err);
                        goto unlock;
@@ -7614,7 +7610,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                                /* Need to clear read-only for this */
                                break;
                        else
-                               err = add_new_disk(mddev, &info);
+                               err = md_add_new_disk(mddev, &info);
                        goto unlock;
                }
                break;
@@ -7682,7 +7678,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                if (copy_from_user(&info, argp, sizeof(info)))
                        err = -EFAULT;
                else
-                       err = add_new_disk(mddev, &info);
+                       err = md_add_new_disk(mddev, &info);
                goto unlock;
        }
 
@@ -7808,7 +7804,7 @@ static int md_revalidate(struct gendisk *disk)
        mddev->changed = 0;
        return 0;
 }
-static const struct block_device_operations md_fops =
+const struct block_device_operations md_fops =
 {
        .owner          = THIS_MODULE,
        .open           = md_open,

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 6f8fff7..ada3106 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -801,7 +801,15 @@ static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio
                mddev->queue->limits.max_write_zeroes_sectors = 0;
 }
 
+struct mdu_array_info_s;
+struct mdu_disk_info_s;
+
 extern int mdp_major;
 void md_autostart_arrays(int part);
+int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info);
+int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info);
+int do_md_run(struct mddev *mddev);
+
+extern const struct block_device_operations md_fops;
 
 #endif /* _MD_MD_H */