diff mbox series

[v4,03/16] block: sed-opal: unify space check in add_token_*

Message ID 1549054223-12220-4-git-send-email-zub@linux.fjfi.cvut.cz (mailing list archive)
State New, archived
Headers show
Series block: sed-opal: support shadow MBR done flag and write | expand

Commit Message

David Kozub Feb. 1, 2019, 8:50 p.m. UTC 
From: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>

All add_token_* functions have a common set of conditions that have to
be checked. Use a common function for those checks in order to avoid
different behaviour as well as code duplication.

Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
---
 block/sed-opal.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

Comments

Christoph Hellwig Feb. 4, 2019, 2:44 p.m. UTC | #1 
On Fri, Feb 01, 2019 at 09:50:10PM +0100, David Kozub wrote:
> From: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
> 
> All add_token_* functions have a common set of conditions that have to
> be checked. Use a common function for those checks in order to avoid
> different behaviour as well as code duplication.
> 
> Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
> Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
> Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
> Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
> ---
>  block/sed-opal.c | 30 +++++++++++++++++++++---------
>  1 file changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/block/sed-opal.c b/block/sed-opal.c
> index 5c123a5b4ab1..980705681806 100644
> --- a/block/sed-opal.c
> +++ b/block/sed-opal.c
> @@ -510,15 +510,29 @@ static int opal_discovery0(struct opal_dev *dev, void *data)
>  	return opal_discovery0_end(dev);
>  }
>  
> -static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
> +static size_t remaining_size(struct opal_dev *cmd)
> +{
> +	return IO_BUFFER_LENGTH - cmd->pos;
> +}

This function seem a little pointless to me, at least as of this patch
where it only has a single user just below.

Otherwise this looks good to me:

Reviewed-by: Christoph Hellwig <hch@lst.de>
David Kozub Feb. 4, 2019, 9:07 p.m. UTC | #2 
On Mon, 4 Feb 2019, Christoph Hellwig wrote:

> On Fri, Feb 01, 2019 at 09:50:10PM +0100, David Kozub wrote:
>> From: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
>>
>> All add_token_* functions have a common set of conditions that have to
>> be checked. Use a common function for those checks in order to avoid
>> different behaviour as well as code duplication.
>>
>> Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
>> Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
>> Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
>> Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
>> ---
>>  block/sed-opal.c | 30 +++++++++++++++++++++---------
>>  1 file changed, 21 insertions(+), 9 deletions(-)
>>
>> diff --git a/block/sed-opal.c b/block/sed-opal.c
>> index 5c123a5b4ab1..980705681806 100644
>> --- a/block/sed-opal.c
>> +++ b/block/sed-opal.c
>> @@ -510,15 +510,29 @@ static int opal_discovery0(struct opal_dev *dev, void *data)
>>  	return opal_discovery0_end(dev);
>>  }
>>
>> -static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
>> +static size_t remaining_size(struct opal_dev *cmd)
>> +{
>> +	return IO_BUFFER_LENGTH - cmd->pos;
>> +}
>
> This function seem a little pointless to me, at least as of this patch
> where it only has a single user just below.

It is eventually used for the second time in 11/16 block: sed-opal: ioctl 
for writing to shadow mbr.

If you feel strongly about this I can exclude it from this commit and 
introduce it in 11/16 (where it then will called from here and from 
write_shadow_mbr).

Best regards,
David
Christoph Hellwig Feb. 4, 2019, 9:09 p.m. UTC | #3 
On Mon, Feb 04, 2019 at 10:07:09PM +0100, David Kozub wrote:
> It is eventually used for the second time in 11/16 block: sed-opal: ioctl
> for writing to shadow mbr.
> 
> If you feel strongly about this I can exclude it from this commit and
> introduce it in 11/16 (where it then will called from here and from
> write_shadow_mbr).

No problem, just keep it.
Jon Derrick Feb. 8, 2019, 10:57 p.m. UTC | #4 
On Mon, 2019-02-04 at 22:07 +0100, David Kozub wrote:
> On Mon, 4 Feb 2019, Christoph Hellwig wrote:
> 
> > On Fri, Feb 01, 2019 at 09:50:10PM +0100, David Kozub wrote:
> > > From: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
> > > 
> > > All add_token_* functions have a common set of conditions that have to
> > > be checked. Use a common function for those checks in order to avoid
> > > different behaviour as well as code duplication.
> > > 
> > > Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
> > > Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
> > > Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
> > > Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
> > > ---
> > >  block/sed-opal.c | 30 +++++++++++++++++++++---------
> > >  1 file changed, 21 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/block/sed-opal.c b/block/sed-opal.c
> > > index 5c123a5b4ab1..980705681806 100644
> > > --- a/block/sed-opal.c
> > > +++ b/block/sed-opal.c
> > > @@ -510,15 +510,29 @@ static int opal_discovery0(struct opal_dev *dev, void *data)
> > >  	return opal_discovery0_end(dev);
> > >  }
> > > 
> > > -static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
> > > +static size_t remaining_size(struct opal_dev *cmd)
> > > +{
> > > +	return IO_BUFFER_LENGTH - cmd->pos;
> > > +}
> > 
> > This function seem a little pointless to me, at least as of this patch
> > where it only has a single user just below.
> 
> It is eventually used for the second time in 11/16 block: sed-opal: ioctl 
> for writing to shadow mbr.
> 
> If you feel strongly about this I can exclude it from this commit and 
> introduce it in 11/16 (where it then will called from here and from 
> write_shadow_mbr).
> 
> Best regards,
> David
I'd prefer this option where we refactor later

Otherwise looks good
Reviewed-by Jon Derrick <jonathan.derrick@intel.com>
diff mbox series

Patch

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 5c123a5b4ab1..980705681806 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -510,15 +510,29 @@  static int opal_discovery0(struct opal_dev *dev, void *data)
 	return opal_discovery0_end(dev);
 }
 
-static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
+static size_t remaining_size(struct opal_dev *cmd)
+{
+	return IO_BUFFER_LENGTH - cmd->pos;
+}
+
+static bool can_add(int *err, struct opal_dev *cmd, size_t len)
 {
 	if (*err)
-		return;
-	if (cmd->pos >= IO_BUFFER_LENGTH - 1) {
-		pr_debug("Error adding u8: end of buffer.\n");
+		return false;
+
+	if (remaining_size(cmd) < len) {
+		pr_debug("Error adding %zu bytes: end of buffer.\n", len);
 		*err = -ERANGE;
-		return;
+		return false;
 	}
+
+	return true;
+}
+
+static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
+{
+	if (!can_add(err, cmd, 1))
+		return;
 	cmd->cmd[cmd->pos++] = tok;
 }
 
@@ -563,9 +577,8 @@  static void add_token_u64(int *err, struct opal_dev *cmd, u64 number)
 	msb = fls64(number);
 	len = DIV_ROUND_UP(msb, 8);
 
-	if (cmd->pos >= IO_BUFFER_LENGTH - len - 1) {
+	if (!can_add(err, cmd, len + 1)) {
 		pr_debug("Error adding u64: end of buffer.\n");
-		*err = -ERANGE;
 		return;
 	}
 	add_short_atom_header(cmd, false, false, len);
@@ -587,9 +600,8 @@  static void add_token_bytestring(int *err, struct opal_dev *cmd,
 		is_short_atom = false;
 	}
 
-	if (len >= IO_BUFFER_LENGTH - cmd->pos - header_len) {
+	if (!can_add(err, cmd, header_len + len)) {
 		pr_debug("Error adding bytestring: end of buffer.\n");
-		*err = -ERANGE;
 		return;
 	}