fs: add new vfs_poll and file_can_poll helpers

These abstract out calls to the poll method in preparation for changes
in how we poll.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2018-03-05 07:26:05 -08:00
Родитель 6e8b704df5
Коммит 9965ed174e
9 изменённых файлов: 32 добавлений и 38 удалений

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@ -113,7 +113,7 @@ static void serial2002_tty_read_poll_wait(struct file *f, int timeout)
long elapsed;
__poll_t mask;
mask = f->f_op->poll(f, &table.pt);
mask = vfs_poll(f, &table.pt);
if (mask & (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN |
EPOLLHUP | EPOLLERR)) {
break;
@ -136,7 +136,7 @@ static int serial2002_tty_read(struct file *f, int timeout)
result = -1;
if (!IS_ERR(f)) {
if (f->f_op->poll) {
if (file_can_poll(f)) {
serial2002_tty_read_poll_wait(f, timeout);
if (kernel_read(f, &ch, 1, &pos) == 1)

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@ -166,7 +166,7 @@ int vfio_virqfd_enable(void *opaque,
init_waitqueue_func_entry(&virqfd->wait, virqfd_wakeup);
init_poll_funcptr(&virqfd->pt, virqfd_ptable_queue_proc);
events = irqfd.file->f_op->poll(irqfd.file, &virqfd->pt);
events = vfs_poll(irqfd.file, &virqfd->pt);
/*
* Check if there was an event already pending on the eventfd

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@ -208,7 +208,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file)
if (poll->wqh)
return 0;
mask = file->f_op->poll(file, &poll->table);
mask = vfs_poll(file, &poll->table);
if (mask)
vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask));
if (mask & EPOLLERR) {

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@ -884,8 +884,7 @@ static __poll_t ep_item_poll(const struct epitem *epi, poll_table *pt,
pt->_key = epi->event.events;
if (!is_file_epoll(epi->ffd.file))
return epi->ffd.file->f_op->poll(epi->ffd.file, pt) &
epi->event.events;
return vfs_poll(epi->ffd.file, pt) & epi->event.events;
ep = epi->ffd.file->private_data;
poll_wait(epi->ffd.file, &ep->poll_wait, pt);
@ -2025,7 +2024,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
/* The target file descriptor must support poll */
error = -EPERM;
if (!tf.file->f_op->poll)
if (!file_can_poll(tf.file))
goto error_tgt_fput;
/* Check if EPOLLWAKEUP is allowed */

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@ -502,14 +502,10 @@ static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
continue;
f = fdget(i);
if (f.file) {
const struct file_operations *f_op;
f_op = f.file->f_op;
mask = DEFAULT_POLLMASK;
if (f_op->poll) {
wait_key_set(wait, in, out,
bit, busy_flag);
mask = (*f_op->poll)(f.file, wait);
}
wait_key_set(wait, in, out, bit,
busy_flag);
mask = vfs_poll(f.file, wait);
fdput(f);
if ((mask & POLLIN_SET) && (in & bit)) {
res_in |= bit;
@ -825,13 +821,10 @@ static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait,
/* userland u16 ->events contains POLL... bitmap */
filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP;
mask = DEFAULT_POLLMASK;
if (f.file->f_op->poll) {
pwait->_key = filter | busy_flag;
mask = f.file->f_op->poll(f.file, pwait);
if (mask & busy_flag)
*can_busy_poll = true;
}
pwait->_key = filter | busy_flag;
mask = vfs_poll(f.file, pwait);
if (mask & busy_flag)
*can_busy_poll = true;
mask &= filter; /* Mask out unneeded events. */
fdput(f);

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@ -74,6 +74,18 @@ static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
pt->_key = ~(__poll_t)0; /* all events enabled */
}
static inline bool file_can_poll(struct file *file)
{
return file->f_op->poll;
}
static inline __poll_t vfs_poll(struct file *file, struct poll_table_struct *pt)
{
if (unlikely(!file->f_op->poll))
return DEFAULT_POLLMASK;
return file->f_op->poll(file, pt);
}
struct poll_table_entry {
struct file *filp;
__poll_t key;

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@ -3849,7 +3849,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
if (ret)
goto out_put_css;
efile.file->f_op->poll(efile.file, &event->pt);
vfs_poll(efile.file, &event->pt);
spin_lock(&memcg->event_list_lock);
list_add(&event->list, &memcg->event_list);

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@ -231,7 +231,7 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
static __poll_t
p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
{
__poll_t ret, n;
__poll_t ret;
struct p9_trans_fd *ts = NULL;
if (client && client->status == Connected)
@ -243,19 +243,9 @@ p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
return EPOLLERR;
}
if (!ts->rd->f_op->poll)
ret = DEFAULT_POLLMASK;
else
ret = ts->rd->f_op->poll(ts->rd, pt);
if (ts->rd != ts->wr) {
if (!ts->wr->f_op->poll)
n = DEFAULT_POLLMASK;
else
n = ts->wr->f_op->poll(ts->wr, pt);
ret = (ret & ~EPOLLOUT) | (n & ~EPOLLIN);
}
ret = vfs_poll(ts->rd, pt);
if (ts->rd != ts->wr)
ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
return ret;
}

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@ -397,7 +397,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
* Check if there was an event already pending on the eventfd
* before we registered, and trigger it as if we didn't miss it.
*/
events = f.file->f_op->poll(f.file, &irqfd->pt);
events = vfs_poll(f.file, &irqfd->pt);
if (events & EPOLLIN)
schedule_work(&irqfd->inject);