From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Subject: include/linux/seq_file.h: introduce DEFINE_SEQ_ATTRIBUTE() helper macro Patch series "seq_file: Introduce DEFINE_SEQ_ATTRIBUTE() helper macro". As discussed in https://lore.kernel.org/lkml/20191129222310.GA3712618@xxxxxxxxx/, we could introduce a new helper macro to reduce losts of boilerplate code, vmstat and kprobes is the example which covert to use it, if this is accepted, I will send out more cleanups. This patch (of 3): Introduce DEFINE_SEQ_ATTRIBUTE() helper macro to decrease code duplication. [akpm@xxxxxxxxxxxxxxxxxxxx: coding style fixes] Link: http://lkml.kernel.org/r/20200509064031.181091-1-wangkefeng.wang@xxxxxxxxxx Link: http://lkml.kernel.org/r/20200509064031.181091-2-wangkefeng.wang@xxxxxxxxxx Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/seq_file.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) --- a/include/linux/seq_file.h~seq_file-introduce-define_seq_attribute-helper-macro +++ a/include/linux/seq_file.h @@ -145,6 +145,25 @@ void *__seq_open_private(struct file *, int seq_open_private(struct file *, const struct seq_operations *, int); int seq_release_private(struct inode *, struct file *); +#define DEFINE_SEQ_ATTRIBUTE(__name) \ +static int __name ## _open(struct inode *inode, struct file *file) \ +{ \ + int ret = seq_open(file, &__name ## _sops); \ + if (!ret && inode->i_private) { \ + struct seq_file *seq_f = file->private_data; \ + seq_f->private = inode->i_private; \ + } \ + return ret; \ +} \ + \ +static const struct file_operations __name ## _fops = { \ + .owner = THIS_MODULE, \ + .open = __name ## _open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = seq_release, \ +} + #define DEFINE_SHOW_ATTRIBUTE(__name) \ static int __name ## _open(struct inode *inode, struct file *file) \ { \ _
