fs: seq_file - add event counter to simplify poll() support
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.
All current users are switched over to use the new counter.
Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 91e31e2..dfc9425 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6394,16 +6394,11 @@
mddev_put(mddev);
}
-struct mdstat_info {
- int event;
-};
-
static int md_seq_show(struct seq_file *seq, void *v)
{
mddev_t *mddev = v;
sector_t sectors;
mdk_rdev_t *rdev;
- struct mdstat_info *mi = seq->private;
struct bitmap *bitmap;
if (v == (void*)1) {
@@ -6415,7 +6410,7 @@
spin_unlock(&pers_lock);
seq_printf(seq, "\n");
- mi->event = atomic_read(&md_event_count);
+ seq->poll_event = atomic_read(&md_event_count);
return 0;
}
if (v == (void*)2) {
@@ -6527,26 +6522,21 @@
static int md_seq_open(struct inode *inode, struct file *file)
{
+ struct seq_file *seq;
int error;
- struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL);
- if (mi == NULL)
- return -ENOMEM;
error = seq_open(file, &md_seq_ops);
if (error)
- kfree(mi);
- else {
- struct seq_file *p = file->private_data;
- p->private = mi;
- mi->event = atomic_read(&md_event_count);
- }
+ return error;
+
+ seq = file->private_data;
+ seq->poll_event = atomic_read(&md_event_count);
return error;
}
static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
{
- struct seq_file *m = filp->private_data;
- struct mdstat_info *mi = m->private;
+ struct seq_file *seq = filp->private_data;
int mask;
poll_wait(filp, &md_event_waiters, wait);
@@ -6554,7 +6544,7 @@
/* always allow read */
mask = POLLIN | POLLRDNORM;
- if (mi->event != atomic_read(&md_event_count))
+ if (seq->poll_event != atomic_read(&md_event_count))
mask |= POLLERR | POLLPRI;
return mask;
}