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. greg k-h