Messages in this thread | | | Date | Thu, 12 Dec 2013 10:27:28 +1100 | From | Ryan Mallon <> | Subject | Re: [PATCH -next 1/3] seq: Add a seq_overflow test. |
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On 11/12/13 16:12, Joe Perches wrote: > seq_printf and seq_puts returns are often misused. > > Instead of checking the seq_printf or seq_puts return, > add a new seq_overflow function to test if a seq_file has > overflowed the available buffer space. > > This will eventually allow seq_printf and seq_puts to be > converted to have a void return instead of the int return > that is often assumed to have a size_t value instead of an > error/no-error value. > > Signed-off-by: Joe Perches <joe@perches.com> > --- > fs/seq_file.c | 15 ++++++++------- > include/linux/seq_file.h | 2 ++ > 2 files changed, 10 insertions(+), 7 deletions(-) > > diff --git a/fs/seq_file.c b/fs/seq_file.c > index 1d641bb..aab0736 100644 > --- a/fs/seq_file.c > +++ b/fs/seq_file.c > @@ -14,16 +14,17 @@ > #include <asm/uaccess.h> > #include <asm/page.h> > > - > -/* > - * seq_files have a buffer which can may overflow. When this happens a larger > - * buffer is reallocated and all the data will be printed again. > - * The overflow state is true when m->count == m->size. > +/** > + * seq_overflow - test if a seq_file has overflowed the space available > + * @m: the seq_file handle > + * > + * Returns -1 when an overflow has occurred, 0 otherwise. > */ > -static bool seq_overflow(struct seq_file *m) > +int seq_overflow(struct seq_file *m) > { > - return m->count == m->size; > + return m->count == m->size ? -1 : 0; > } > +EXPORT_SYMBOL(seq_overflow);
What is the reasoning in making this return int instead of bool? Having it return int encourages people to do:
return seq_overflow(s);
When used in seq_file functions will return -EPERM (-1) to user-space, which is confusing. It should probably return bool and let the caller sort out the correct error to return.
~Ryan
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