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| author | Namhyung Kim <namhyung@gmail.com> | 2011-05-28 14:44:46 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-05-28 14:44:46 +0200 |
| commit | 5988ce239682854d4e632fb58bff000700830394 (patch) | |
| tree | 442b44bb96632b7ed507bc5eeacd10fafc689afd /drivers/block | |
| parent | 3b2710824e00d238554c13b5add347e6c701ab1a (diff) | |
| download | linux-5988ce239682854d4e632fb58bff000700830394.tar.gz linux-5988ce239682854d4e632fb58bff000700830394.tar.bz2 linux-5988ce239682854d4e632fb58bff000700830394.zip | |
nbd: adjust 'max_part' according to part_shift
The 'max_part' parameter determines how many partitions are supported
on each nbd device. However the actual number can be changed to the
power of 2 minus 1 form during the module initialization as
alloc_disk() is called with (1 << part_shift) for some reason.
So adjust 'max_part' also at least for consistency with loop and brd.
It is exported via sysfs already, and a user should check this value
after module loading if [s]he wants to use that number correctly
(i.e. fdisk or something).
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/nbd.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index fdee7567fd15..f533f3375e24 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -754,9 +754,20 @@ static int __init nbd_init(void) return -ENOMEM; part_shift = 0; - if (max_part > 0) + if (max_part > 0) { part_shift = fls(max_part); + /* + * Adjust max_part according to part_shift as it is exported + * to user space so that user can know the max number of + * partition kernel should be able to manage. + * + * Note that -1 is required because partition 0 is reserved + * for the whole disk. + */ + max_part = (1UL << part_shift) - 1; + } + if ((1UL << part_shift) > DISK_MAX_PARTS) return -EINVAL; |