Commit f1514638 authored by Kay Sievers's avatar Kay Sievers Committed by Al Viro

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: default avatarNeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 72c5052d
......@@ -6394,16 +6394,11 @@ static void md_seq_stop(struct seq_file *seq, void *v)
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 @@ static int md_seq_show(struct seq_file *seq, void *v)
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 const struct seq_operations md_seq_ops = {
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 @@ static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
/* 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;
}
......
......@@ -934,8 +934,8 @@ int mnt_had_events(struct proc_mounts *p)
int res = 0;
br_read_lock(vfsmount_lock);
if (p->event != ns->event) {
p->event = ns->event;
if (p->m.poll_event != ns->event) {
p->m.poll_event = ns->event;
res = 1;
}
br_read_unlock(vfsmount_lock);
......
......@@ -673,7 +673,7 @@ static int mounts_open_common(struct inode *inode, struct file *file,
p->m.private = p;
p->ns = ns;
p->root = root;
p->event = ns->event;
p->m.poll_event = ns->event;
return 0;
......
......@@ -18,7 +18,6 @@ struct proc_mounts {
struct seq_file m; /* must be the first element */
struct mnt_namespace *ns;
struct path root;
int event;
};
struct fs_struct;
......
......@@ -23,6 +23,7 @@ struct seq_file {
u64 version;
struct mutex lock;
const struct seq_operations *op;
int poll_event;
void *private;
};
......
......@@ -1681,19 +1681,14 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
}
#ifdef CONFIG_PROC_FS
struct proc_swaps {
struct seq_file seq;
int event;
};
static unsigned swaps_poll(struct file *file, poll_table *wait)
{
struct proc_swaps *s = file->private_data;
struct seq_file *seq = file->private_data;
poll_wait(file, &proc_poll_wait, wait);
if (s->event != atomic_read(&proc_poll_event)) {
s->event = atomic_read(&proc_poll_event);
if (seq->poll_event != atomic_read(&proc_poll_event)) {
seq->poll_event = atomic_read(&proc_poll_event);
return POLLIN | POLLRDNORM | POLLERR | POLLPRI;
}
......@@ -1783,24 +1778,16 @@ static const struct seq_operations swaps_op = {
static int swaps_open(struct inode *inode, struct file *file)
{
struct proc_swaps *s;
struct seq_file *seq;
int ret;
s = kmalloc(sizeof(struct proc_swaps), GFP_KERNEL);
if (!s)
return -ENOMEM;
file->private_data = s;
ret = seq_open(file, &swaps_op);
if (ret) {
kfree(s);
if (ret)
return ret;
}
s->seq.private = s;
s->event = atomic_read(&proc_poll_event);
return ret;
seq = file->private_data;
seq->poll_event = atomic_read(&proc_poll_event);
return 0;
}
static const struct file_operations proc_swaps_operations = {
......
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