[PATCH] s390: dasd partition detection

DASD allows to open a device as soon as gendisk is registered, which means the
device is a fake device (capacity=0) and we do know nothing about blocksize
and partitions at that point of time.  In case the device is opened by
someone, the bdev and inode creation is done with the fake device info and the
following partition detection code is just using the wrong data.

To avoid this modify the DASD state machine to make sure that the open is
rejected until the device analysis is either finished or an unformatted device
was detected.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/fs/partitions/ibm.c b/fs/partitions/ibm.c
index 78010ad60e47..1e4a93835fed 100644
--- a/fs/partitions/ibm.c
+++ b/fs/partitions/ibm.c
@@ -52,6 +52,7 @@ int
 ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
 {
         int blocksize, offset, size;
+        loff_t i_size;
         dasd_information_t *info;
         struct hd_geometry *geo;
         char type[5] = {0,};
@@ -63,6 +64,13 @@ ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
         unsigned char *data;
         Sector sect;
 
+        blocksize = bdev_hardsect_size(bdev);
+        if (blocksize <= 0)
+                return 0;
+        i_size = i_size_read(bdev->bd_inode);
+        if (i_size == 0)
+                return 0;
+
         if ((info = kmalloc(sizeof(dasd_information_t), GFP_KERNEL)) == NULL)
                 goto out_noinfo;
         if ((geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL)) == NULL)
@@ -73,9 +81,6 @@ ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
         if (ioctl_by_bdev(bdev, BIODASDINFO, (unsigned long)info) != 0 ||
             ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
                 goto out_noioctl;
-        
-        if ((blocksize = bdev_hardsect_size(bdev)) <= 0)
-                goto out_badsect;
 
         /*
          * Get volume label, extract name and type.
@@ -111,7 +116,7 @@ ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
                 } else {
                         printk("CMS1/%8s:", name);
                         offset = (info->label_block + 1);
-                        size = bdev->bd_inode->i_size >> 9;
+                        size = i_size >> 9;
                 }
                 put_partition(state, 1, offset*(blocksize >> 9),
                                  size-offset*(blocksize >> 9));
@@ -168,7 +173,7 @@ ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
                 else
                         printk("(nonl)/%8s:", name);
                 offset = (info->label_block + 1);
-                size = (bdev->bd_inode->i_size >> 9);
+                size = i_size >> 9;
                 put_partition(state, 1, offset*(blocksize >> 9),
                                  size-offset*(blocksize >> 9));
         }
@@ -180,7 +185,6 @@ ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
         return 1;
         
 out_readerr:
-out_badsect:
 out_noioctl:
         kfree(label);
 out_nolab: