On 2/6/18 2:24 AM, Greg KH wrote:
> On Mon, Feb 05, 2018 at 06:25:27PM -0800, Srivatsa S. Bhat wrote:
>> From: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx>
>>
>> register_blkdev() and __register_chrdev_region() treat the major
>> number as an unsigned int. So print it the same way to avoid
>> absurd error statements such as:
>> "... major requested (-1) is greater than the maximum (511) ..."
>> (and also fix off-by-one bugs in the error prints).
>>
>> While at it, also update the comment describing register_blkdev().
>>
>> Signed-off-by: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx>
>> ---
>>
>> block/genhd.c | 19 +++++++++++--------
>> fs/char_dev.c | 4 ++--
>> 2 files changed, 13 insertions(+), 10 deletions(-)
>>
>> diff --git a/block/genhd.c b/block/genhd.c
>> index 88a53c1..21a18e5 100644
>> --- a/block/genhd.c
>> +++ b/block/genhd.c
>> @@ -308,19 +308,22 @@ void blkdev_show(struct seq_file *seqf, off_t offset)
>> /**
>> * register_blkdev - register a new block device
>> *
>> - * @major: the requested major device number [1..255]. If @major = 0, try to
>> - * allocate any unused major number.
>> + * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
>> + * @major = 0, try to allocate any unused major number.
>> * @name: the name of the new block device as a zero terminated string
>> *
>> * The @name must be unique within the system.
>> *
>> * The return value depends on the @major input parameter:
>> *
>> - * - if a major device number was requested in range [1..255] then the
>> - * function returns zero on success, or a negative error code
>> + * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
>> + * then the function returns zero on success, or a negative error code
>> * - if any unused major number was requested with @major = 0 parameter
>> * then the return value is the allocated major number in range
>> - * [1..255] or a negative error code otherwise
>> + * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
>> + *
>> + * See Documentation/admin-guide/devices.txt for the list of allocated
>> + * major numbers.
>> */
>> int register_blkdev(unsigned int major, const char *name)
>> {
>> @@ -347,8 +350,8 @@ int register_blkdev(unsigned int major, const char *name)
>> }
>>
>> if (major >= BLKDEV_MAJOR_MAX) {
>> - pr_err("register_blkdev: major requested (%d) is greater than the maximum (%d) for %s\n",
>> - major, BLKDEV_MAJOR_MAX, name);
>> + pr_err("register_blkdev: major requested (%u) is greater than the maximum (%u) for %s\n",
>> + major, BLKDEV_MAJOR_MAX-1, name);
>>
>> ret = -EINVAL;
>> goto out;
>> @@ -375,7 +378,7 @@ int register_blkdev(unsigned int major, const char *name)
>> ret = -EBUSY;
>>
>> if (ret < 0) {
>> - printk("register_blkdev: cannot get major %d for %s\n",
>> + printk("register_blkdev: cannot get major %u for %s\n",
>> major, name);
>> kfree(p);
>> }
>> diff --git a/fs/char_dev.c b/fs/char_dev.c
>> index 33c9385..a279c58 100644
>> --- a/fs/char_dev.c
>> +++ b/fs/char_dev.c
>> @@ -121,8 +121,8 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
>> }
>>
>> if (major >= CHRDEV_MAJOR_MAX) {
>> - pr_err("CHRDEV \"%s\" major requested (%d) is greater than the maximum (%d)\n",
>> - name, major, CHRDEV_MAJOR_MAX);
>> + pr_err("CHRDEV \"%s\" major requested (%u) is greater than the maximum (%u)\n",
>> + name, major, CHRDEV_MAJOR_MAX-1);
>> ret = -EINVAL;
>> goto out;
>> }
>
> Thanks for both of these patches, if Al doesn't grab them, I will after
> 4.16-rc1 comes out.
>
Sounds great! Thank you!
Regards,
Srivatsa
