summaryrefslogtreecommitdiff
path: root/fs/select.c
diff options
context:
space:
mode:
authorTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-24 08:41:41 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-24 13:07:53 -0400
commit816724e65c72a90a44fbad0ef0b59b186c85fa90 (patch)
tree421fa29aedff988e392f92780637553e275d37a0 /fs/select.c
parent70ac4385a13f78bc478f26d317511893741b05bd (diff)
parentd384ea691fe4ea8c2dd5b9b8d9042eb181776f18 (diff)
Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Conflicts: fs/nfs/inode.c fs/super.c Fix conflicts between patch 'NFS: Split fs/nfs/inode.c' and patch 'VFS: Permit filesystem to override root dentry on mount'
Diffstat (limited to 'fs/select.c')
-rw-r--r--fs/select.c83
1 files changed, 51 insertions, 32 deletions
diff --git a/fs/select.c b/fs/select.c
index a8109baa5e46..9c4f0f2604f1 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -546,37 +546,38 @@ struct poll_list {
#define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd))
-static void do_pollfd(unsigned int num, struct pollfd * fdpage,
- poll_table ** pwait, int *count)
+/*
+ * Fish for pollable events on the pollfd->fd file descriptor. We're only
+ * interested in events matching the pollfd->events mask, and the result
+ * matching that mask is both recorded in pollfd->revents and returned. The
+ * pwait poll_table will be used by the fd-provided poll handler for waiting,
+ * if non-NULL.
+ */
+static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
{
- int i;
-
- for (i = 0; i < num; i++) {
- int fd;
- unsigned int mask;
- struct pollfd *fdp;
-
- mask = 0;
- fdp = fdpage+i;
- fd = fdp->fd;
- if (fd >= 0) {
- int fput_needed;
- struct file * file = fget_light(fd, &fput_needed);
- mask = POLLNVAL;
- if (file != NULL) {
- mask = DEFAULT_POLLMASK;
- if (file->f_op && file->f_op->poll)
- mask = file->f_op->poll(file, *pwait);
- mask &= fdp->events | POLLERR | POLLHUP;
- fput_light(file, fput_needed);
- }
- if (mask) {
- *pwait = NULL;
- (*count)++;
- }
+ unsigned int mask;
+ int fd;
+
+ mask = 0;
+ fd = pollfd->fd;
+ if (fd >= 0) {
+ int fput_needed;
+ struct file * file;
+
+ file = fget_light(fd, &fput_needed);
+ mask = POLLNVAL;
+ if (file != NULL) {
+ mask = DEFAULT_POLLMASK;
+ if (file->f_op && file->f_op->poll)
+ mask = file->f_op->poll(file, pwait);
+ /* Mask out unneeded events. */
+ mask &= pollfd->events | POLLERR | POLLHUP;
+ fput_light(file, fput_needed);
}
- fdp->revents = mask;
}
+ pollfd->revents = mask;
+
+ return mask;
}
static int do_poll(unsigned int nfds, struct poll_list *list,
@@ -594,11 +595,29 @@ static int do_poll(unsigned int nfds, struct poll_list *list,
long __timeout;
set_current_state(TASK_INTERRUPTIBLE);
- walk = list;
- while(walk != NULL) {
- do_pollfd( walk->len, walk->entries, &pt, &count);
- walk = walk->next;
+ for (walk = list; walk != NULL; walk = walk->next) {
+ struct pollfd * pfd, * pfd_end;
+
+ pfd = walk->entries;
+ pfd_end = pfd + walk->len;
+ for (; pfd != pfd_end; pfd++) {
+ /*
+ * Fish for events. If we found one, record it
+ * and kill the poll_table, so we don't
+ * needlessly register any other waiters after
+ * this. They'll get immediately deregistered
+ * when we break out and return.
+ */
+ if (do_pollfd(pfd, pt)) {
+ count++;
+ pt = NULL;
+ }
+ }
}
+ /*
+ * All waiters have already been registered, so don't provide
+ * a poll_table to them on the next loop iteration.
+ */
pt = NULL;
if (count || !*timeout || signal_pending(current))
break;