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authorLaurent Vivier <Laurent.Vivier@bull.net>2008-04-30 00:55:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:53 -0700
commitd7853d1f8932c847a8d7b3b38e6baedf77148cfb (patch)
tree7307493afd5fd728150c1848509942461064ea5f
parentadd hrtimer specific debugobjects code (diff)
downloadlinux-dev-d7853d1f8932c847a8d7b3b38e6baedf77148cfb.tar.xz
linux-dev-d7853d1f8932c847a8d7b3b38e6baedf77148cfb.zip
brd: modify ramdisk device to be able to manage partitions
This patch adds partition management for Block RAM Device (BRD). This patch is done to keep in sync BRD and loop device drivers. This patch adds a parameter to the module, max_part, to specify the maximum number of partitions per RAM device. Example: # modprobe brd max_part=63 # ls -l /dev/ram* brw-rw---- 1 root disk 1, 0 2008-04-03 13:39 /dev/ram0 brw-rw---- 1 root disk 1, 64 2008-04-03 13:39 /dev/ram1 brw-rw---- 1 root disk 1, 640 2008-04-03 13:39 /dev/ram10 brw-rw---- 1 root disk 1, 704 2008-04-03 13:39 /dev/ram11 brw-rw---- 1 root disk 1, 768 2008-04-03 13:39 /dev/ram12 brw-rw---- 1 root disk 1, 832 2008-04-03 13:39 /dev/ram13 brw-rw---- 1 root disk 1, 896 2008-04-03 13:39 /dev/ram14 brw-rw---- 1 root disk 1, 960 2008-04-03 13:39 /dev/ram15 brw-rw---- 1 root disk 1, 128 2008-04-03 13:39 /dev/ram2 brw-rw---- 1 root disk 1, 192 2008-04-03 13:39 /dev/ram3 brw-rw---- 1 root disk 1, 256 2008-04-03 13:39 /dev/ram4 brw-rw---- 1 root disk 1, 320 2008-04-03 13:39 /dev/ram5 brw-rw---- 1 root disk 1, 384 2008-04-03 13:39 /dev/ram6 brw-rw---- 1 root disk 1, 448 2008-04-03 13:39 /dev/ram7 brw-rw---- 1 root disk 1, 512 2008-04-03 13:39 /dev/ram8 brw-rw---- 1 root disk 1, 576 2008-04-03 13:39 /dev/ram9 # fdisk /dev/ram0 Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): o Building a new DOS disklabel. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-2, default 1): 1 Last cylinder or +size or +sizeM or +sizeK (1-2, default 2): 2 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. # ls -l /dev/ram0* brw-rw---- 1 root disk 1, 0 2008-04-03 13:40 /dev/ram0 brw-rw---- 1 root disk 1, 1 2008-04-03 13:40 /dev/ram0p1 # mkfs /dev/ram0p1 mke2fs 1.40-WIP (14-Nov-2006) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) 4016 inodes, 16032 blocks 801 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=16515072 2 block groups 8192 blocks per group, 8192 fragments per group 2008 inodes per group Superblock backups stored on blocks: 8193 Writing inode tables: done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 26 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. # mount /dev/ram0p1 /mnt df /mnt Filesystem 1K-blocks Used Available Use% Mounted on /dev/ram0p1 15521 138 14582 1% /mnt # ls -l /mnt total 12 drwx------ 2 root root 12288 2008-04-03 13:41 lost+found # umount /mnt # rmmod brd Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--drivers/block/brd.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index e8e38faeafd8..a196ef7f147f 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -387,10 +387,14 @@ static struct block_device_operations brd_fops = {
*/
static int rd_nr;
int rd_size = CONFIG_BLK_DEV_RAM_SIZE;
+static int max_part;
+static int part_shift;
module_param(rd_nr, int, 0);
MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices");
module_param(rd_size, int, 0);
MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");
+module_param(max_part, int, 0);
+MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
@@ -435,11 +439,11 @@ static struct brd_device *brd_alloc(int i)
blk_queue_max_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
- disk = brd->brd_disk = alloc_disk(1);
+ disk = brd->brd_disk = alloc_disk(1 << part_shift);
if (!disk)
goto out_free_queue;
disk->major = RAMDISK_MAJOR;
- disk->first_minor = i;
+ disk->first_minor = i << part_shift;
disk->fops = &brd_fops;
disk->private_data = brd;
disk->queue = brd->brd_queue;
@@ -523,7 +527,12 @@ static int __init brd_init(void)
* themselves and have kernel automatically instantiate actual
* device on-demand.
*/
- if (rd_nr > 1UL << MINORBITS)
+
+ part_shift = 0;
+ if (max_part > 0)
+ part_shift = fls(max_part);
+
+ if (rd_nr > 1UL << (MINORBITS - part_shift))
return -EINVAL;
if (rd_nr) {
@@ -531,7 +540,7 @@ static int __init brd_init(void)
range = rd_nr;
} else {
nr = CONFIG_BLK_DEV_RAM_COUNT;
- range = 1UL << MINORBITS;
+ range = 1UL << (MINORBITS - part_shift);
}
if (register_blkdev(RAMDISK_MAJOR, "ramdisk"))
@@ -570,7 +579,7 @@ static void __exit brd_exit(void)
unsigned long range;
struct brd_device *brd, *next;
- range = rd_nr ? rd_nr : 1UL << MINORBITS;
+ range = rd_nr ? rd_nr : 1UL << (MINORBITS - part_shift);
list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
brd_del_one(brd);