* [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major()
@ 2018-02-06 2:25 Srivatsa S. Bhat
2018-02-06 2:25 ` [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints Srivatsa S. Bhat
2018-02-06 17:14 ` [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Logan Gunthorpe
0 siblings, 2 replies; 6+ messages in thread
From: Srivatsa S. Bhat @ 2018-02-06 2:25 UTC (permalink / raw)
To: gregkh, logang
Cc: axboe, jlayton, bfields, viro, linux-fsdevel, linux-block,
linux-kernel, srivatsa
From: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
CHRDEV_MAJOR_DYN_END and CHRDEV_MAJOR_DYN_EXT_END are valid major
numbers. So fix the loop iteration to include them in the search for
free major numbers.
While at it, also remove a redundant if condition ("cd->major != i"),
as it will never be true.
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
---
fs/char_dev.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/char_dev.c b/fs/char_dev.c
index a65e4a5..33c9385 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -67,18 +67,18 @@ static int find_dynamic_major(void)
int i;
struct char_device_struct *cd;
- for (i = ARRAY_SIZE(chrdevs)-1; i > CHRDEV_MAJOR_DYN_END; i--) {
+ for (i = ARRAY_SIZE(chrdevs)-1; i >= CHRDEV_MAJOR_DYN_END; i--) {
if (chrdevs[i] == NULL)
return i;
}
for (i = CHRDEV_MAJOR_DYN_EXT_START;
- i > CHRDEV_MAJOR_DYN_EXT_END; i--) {
+ i >= CHRDEV_MAJOR_DYN_EXT_END; i--) {
for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next)
if (cd->major == i)
break;
- if (cd == NULL || cd->major != i)
+ if (cd == NULL)
return i;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints
2018-02-06 2:25 [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Srivatsa S. Bhat
@ 2018-02-06 2:25 ` Srivatsa S. Bhat
2018-02-06 10:24 ` Greg KH
2018-02-06 17:15 ` Logan Gunthorpe
2018-02-06 17:14 ` [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Logan Gunthorpe
1 sibling, 2 replies; 6+ messages in thread
From: Srivatsa S. Bhat @ 2018-02-06 2:25 UTC (permalink / raw)
To: gregkh, logang
Cc: axboe, jlayton, bfields, viro, linux-fsdevel, linux-block,
linux-kernel, srivatsa
From: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
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@csail.mit.edu>
---
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;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints
2018-02-06 2:25 ` [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints Srivatsa S. Bhat
@ 2018-02-06 10:24 ` Greg KH
2018-02-06 19:58 ` Srivatsa S. Bhat
2018-02-06 17:15 ` Logan Gunthorpe
1 sibling, 1 reply; 6+ messages in thread
From: Greg KH @ 2018-02-06 10:24 UTC (permalink / raw)
To: Srivatsa S. Bhat
Cc: logang, axboe, jlayton, bfields, viro, linux-fsdevel,
linux-block, linux-kernel
On Mon, Feb 05, 2018 at 06:25:27PM -0800, Srivatsa S. Bhat wrote:
> From: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
>
> 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@csail.mit.edu>
> ---
>
> 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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major()
2018-02-06 2:25 [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Srivatsa S. Bhat
2018-02-06 2:25 ` [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints Srivatsa S. Bhat
@ 2018-02-06 17:14 ` Logan Gunthorpe
1 sibling, 0 replies; 6+ messages in thread
From: Logan Gunthorpe @ 2018-02-06 17:14 UTC (permalink / raw)
To: Srivatsa S. Bhat, gregkh
Cc: axboe, jlayton, bfields, viro, linux-fsdevel, linux-block, linux-kernel
Thanks!
On 05/02/18 07:25 PM, Srivatsa S. Bhat wrote:
> From: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
>
> CHRDEV_MAJOR_DYN_END and CHRDEV_MAJOR_DYN_EXT_END are valid major
> numbers. So fix the loop iteration to include them in the search for
> free major numbers.
>
> While at it, also remove a redundant if condition ("cd->major != i"),
> as it will never be true.
>
> Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Logan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints
2018-02-06 2:25 ` [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints Srivatsa S. Bhat
2018-02-06 10:24 ` Greg KH
@ 2018-02-06 17:15 ` Logan Gunthorpe
1 sibling, 0 replies; 6+ messages in thread
From: Logan Gunthorpe @ 2018-02-06 17:15 UTC (permalink / raw)
To: Srivatsa S. Bhat, gregkh
Cc: axboe, jlayton, bfields, viro, linux-fsdevel, linux-block, linux-kernel
On 05/02/18 07:25 PM, Srivatsa S. Bhat wrote:
> From: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
>
> 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@csail.mit.edu>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints
2018-02-06 10:24 ` Greg KH
@ 2018-02-06 19:58 ` Srivatsa S. Bhat
0 siblings, 0 replies; 6+ messages in thread
From: Srivatsa S. Bhat @ 2018-02-06 19:58 UTC (permalink / raw)
To: Greg KH
Cc: logang, axboe, jlayton, bfields, viro, linux-fsdevel,
linux-block, linux-kernel
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@csail.mit.edu>
>>
>> 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@csail.mit.edu>
>> ---
>>
>> 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
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-02-06 19:58 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2018-02-06 2:25 [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Srivatsa S. Bhat
2018-02-06 2:25 ` [PATCH 2/2] block, char_dev: Use correct format specifier for unsigned ints Srivatsa S. Bhat
2018-02-06 10:24 ` Greg KH
2018-02-06 19:58 ` Srivatsa S. Bhat
2018-02-06 17:15 ` Logan Gunthorpe
2018-02-06 17:14 ` [PATCH 1/2] char_dev: Fix off-by-one bugs in find_dynamic_major() Logan Gunthorpe
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