| Message ID | 4E38AB50.9040804@gmail.com |
|---|---|
| State | New, archived |
| Headers | show |
09:58, Wang Sheng-Hui wrote: > The patch is against 3.0 > > The arg of kjournald/kjournald2 is void *, and points to type > journal_t. We should convert it to journal_t * explicitly in > the kjournald/kjournald2 function body. > Why? Implicit convertion from void * to foo * is ok. Did the compiler complain about this to you? > Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> > --- > fs/jbd/journal.c | 2 +- > fs/jbd2/journal.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c > index e2d4285..32956fd 100644 > --- a/fs/jbd/journal.c > +++ b/fs/jbd/journal.c > @@ -116,7 +116,7 @@ static void commit_timeout(unsigned long __data) > > static int kjournald(void *arg) > { > - journal_t *journal = arg; > + journal_t *journal = (journal_t *)arg; > transaction_t *transaction; > > /* > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 0dfa5b5..c4f4bfc 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -129,7 +129,7 @@ static void commit_timeout(unsigned long __data) > > static int kjournald2(void *arg) > { > - journal_t *journal = arg; > + journal_t *journal = (journal_t *)arg; > transaction_t *transaction; > > /* -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2011年08月03日 10:04, Li Zefan wrote: > 09:58, Wang Sheng-Hui wrote: >> The patch is against 3.0 >> >> The arg of kjournald/kjournald2 is void *, and points to type >> journal_t. We should convert it to journal_t * explicitly in >> the kjournald/kjournald2 function body. >> > > Why? > > Implicit convertion from void * to foo * is ok. Did the compiler > complain about this to you? I remember any * can be assigned directly to void * in ANSI C, but void * should be converted to specific point * type. Right? And I checked the code of kswapd, in which explicitly conversion is taken on the arg *. I think it should do so in journal.c too. > >> Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> >> --- >> fs/jbd/journal.c | 2 +- >> fs/jbd2/journal.c | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c >> index e2d4285..32956fd 100644 >> --- a/fs/jbd/journal.c >> +++ b/fs/jbd/journal.c >> @@ -116,7 +116,7 @@ static void commit_timeout(unsigned long __data) >> >> static int kjournald(void *arg) >> { >> - journal_t *journal = arg; >> + journal_t *journal = (journal_t *)arg; >> transaction_t *transaction; >> >> /* >> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c >> index 0dfa5b5..c4f4bfc 100644 >> --- a/fs/jbd2/journal.c >> +++ b/fs/jbd2/journal.c >> @@ -129,7 +129,7 @@ static void commit_timeout(unsigned long __data) >> >> static int kjournald2(void *arg) >> { >> - journal_t *journal = arg; >> + journal_t *journal = (journal_t *)arg; >> transaction_t *transaction; >> >> /* -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Wang Sheng-Hui wrote: > On 2011年08月03日 10:04, Li Zefan wrote: >> 09:58, Wang Sheng-Hui wrote: >>> The patch is against 3.0 >>> >>> The arg of kjournald/kjournald2 is void *, and points to type >>> journal_t. We should convert it to journal_t * explicitly in >>> the kjournald/kjournald2 function body. >>> >> >> Why? >> >> Implicit convertion from void * to foo * is ok. Did the compiler >> complain about this to you? > > I remember any * can be assigned directly to void * in ANSI C, but > void * should be converted to specific point * type. Right? > No. > And I checked the code of kswapd, in which explicitly conversion is > taken on the arg *. I think it should do so in journal.c too. > Please check more similar code. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Aug 3, 2011 at 10:17 AM, Wang Sheng-Hui <shhuiw@gmail.com> wrote: > > I remember any * can be assigned directly to void * in ANSI C, but > void * should be converted to specific point * type. Right? > C99 6.3.2.3 A pointer to void may be converted to or from a pointer to any incomplete or object type. A pointer to any incomplete or object type may be converted to a pointer to void and back again; the result shall compare equal to the original pointer. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2011年08月03日 10:52, Américo Wang wrote: > On Wed, Aug 3, 2011 at 10:17 AM, Wang Sheng-Hui <shhuiw@gmail.com> wrote: >> >> I remember any * can be assigned directly to void * in ANSI C, but >> void * should be converted to specific point * type. Right? >> > > C99 6.3.2.3 Got it. Thanks, > > A pointer to void may be converted to or from a pointer to any > incomplete or object > type. A pointer to any incomplete or object type may be converted to a > pointer to void > and back again; the result shall compare equal to the original pointer. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On Tue, Aug 2, 2011 at 10:17 PM, Wang Sheng-Hui <shhuiw@gmail.com> wrote: > And I checked the code of kswapd, in which explicitly conversion is > taken on the arg *. I think it should do so in journal.c too. > because it is done wrong somewhere is no argument to do it wrong here ... - Arnaud -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 3 Aug 2011, Li Zefan wrote: > 09:58, Wang Sheng-Hui wrote: > > The patch is against 3.0 > > > > The arg of kjournald/kjournald2 is void *, and points to type > > journal_t. We should convert it to journal_t * explicitly in > > the kjournald/kjournald2 function body. > > > > Why? > > Implicit convertion from void * to foo * is ok. Did the compiler > complain about this to you? > Not only is it perfectly OK to rely on the implicit conversion, a lot of work has gone into actively removing such unneeded explicit casts over the years, so let's not introduce new ones.
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index e2d4285..32956fd 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -116,7 +116,7 @@ static void commit_timeout(unsigned long __data) static int kjournald(void *arg) { - journal_t *journal = arg; + journal_t *journal = (journal_t *)arg; transaction_t *transaction; /* diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 0dfa5b5..c4f4bfc 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -129,7 +129,7 @@ static void commit_timeout(unsigned long __data) static int kjournald2(void *arg) { - journal_t *journal = arg; + journal_t *journal = (journal_t *)arg; transaction_t *transaction; /*
The patch is against 3.0 The arg of kjournald/kjournald2 is void *, and points to type journal_t. We should convert it to journal_t * explicitly in the kjournald/kjournald2 function body. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> --- fs/jbd/journal.c | 2 +- fs/jbd2/journal.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)