[PATCH 05/12] eliminate goto and improve readability

Ed L. Cashin
2007-06-26T19:05:55Z

Adam Richter suggested eliminating this goto.

Signed-off-by: Ed L. Cashin <ecashin@coraid.com>
---
drivers/block/aoe/aoechr.c | 69 +++++++++++++++++++++----------------------
1 files changed, 34 insertions(+), 35 deletions(-)

diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index 9026c44..511f995 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -191,52 +191,51 @@ aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
ulong flags;

n = (unsigned long) filp->private_data;
- switch (n) {
- case MINOR_ERR:
- spin_lock_irqsave(&emsgs_lock, flags);
-loop:
- em = emsgs + emsgs_head_idx;
- if ((em->flags & EMFL_VALID) == 0) {
- if (filp->f_flags & O_NDELAY) {
- spin_unlock_irqrestore(&emsgs_lock, flags);
- return -EAGAIN;
- }
- nblocked_emsgs_readers++;
+ if (n != MINOR_ERR)
+ return -EFAULT;
+
+ spin_lock_irqsave(&emsgs_lock, flags);

+ for (;;) {
+ em = emsgs + emsgs_head_idx;
+ if ((em->flags & EMFL_VALID) != 0)
+ break;
+ if (filp->f_flags & O_NDELAY) {
spin_unlock_irqrestore(&emsgs_lock, flags);
+ return -EAGAIN;
+ }
+ nblocked_emsgs_readers++;
+
+ spin_unlock_irqrestore(&emsgs_lock, flags);

- n = down_interruptible(&emsgs_sema);
+ n = down_interruptible(&emsgs_sema);

- spin_lock_irqsave(&emsgs_lock, flags);
+ spin_lock_irqsave(&emsgs_lock, flags);

- nblocked_emsgs_readers--;
+ nblocked_emsgs_readers--;

- if (n) {
- spin_unlock_irqrestore(&emsgs_lock, flags);
- return -ERESTARTSYS;
- }
- goto loop;
- }
- if (em->len > cnt) {
+ if (n) {
spin_unlock_irqrestore(&emsgs_lock, flags);
- return -EAGAIN;
+ return -ERESTARTSYS;
}
- mp = em->msg;
- len = em->len;
- em->msg = NULL;
- em->flags &= ~EMFL_VALID;
+ }
+ if (em->len > cnt) {
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+ return -EAGAIN;
+ }
+ mp = em->msg;
+ len = em->len;
+ em->msg = NULL;
+ em->flags &= ~EMFL_VALID;

- emsgs_head_idx++;
- emsgs_head_idx %= ARRAY_SIZE(emsgs);
+ emsgs_head_idx++;
+ emsgs_head_idx %= ARRAY_SIZE(emsgs);

- spin_unlock_irqrestore(&emsgs_lock, flags);
+ spin_unlock_irqrestore(&emsgs_lock, flags);

- n = copy_to_user(buf, mp, len);
- kfree(mp);
- return n == 0 ? len : -EFAULT;
- default:
- return -EFAULT;
- }
+ n = copy_to_user(buf, mp, len);
+ kfree(mp);
+ return n == 0 ? len : -EFAULT;
}

static const struct file_operations aoe_fops = {
--
1.5.2.1