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-rw-r--r--Documentation/filesystems/vfs.txt15
1 files changed, 14 insertions, 1 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 5fd325df59e2..829a7b7857a4 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -856,7 +856,9 @@ struct file_operations {
ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
int (*iterate) (struct file *, struct dir_context *);
- unsigned int (*poll) (struct file *, struct poll_table_struct *);
+ __poll_t (*poll) (struct file *, struct poll_table_struct *);
+ struct wait_queue_head * (*get_poll_head)(struct file *, __poll_t);
+ __poll_t (*poll_mask) (struct file *, __poll_t);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
@@ -901,6 +903,17 @@ otherwise noted.
activity on this file and (optionally) go to sleep until there
is activity. Called by the select(2) and poll(2) system calls
+ get_poll_head: Returns the struct wait_queue_head that callers can
+ wait on. Callers need to check the returned events using ->poll_mask
+ once woken. Can return NULL to indicate polling is not supported,
+ or any error code using the ERR_PTR convention to indicate that a
+ grave error occured and ->poll_mask shall not be called.
+
+ poll_mask: return the mask of EPOLL* values describing the file descriptor
+ state. Called either before going to sleep on the waitqueue returned by
+ get_poll_head, or after it has been woken. If ->get_poll_head and
+ ->poll_mask are implemented ->poll does not need to be implement.
+
unlocked_ioctl: called by the ioctl(2) system call.
compat_ioctl: called by the ioctl(2) system call when 32 bit system calls