diff options
| -rw-r--r-- | fs/eventfd.c | 64 |
1 files changed, 38 insertions, 26 deletions
diff --git a/fs/eventfd.c b/fs/eventfd.c index 78e41c7c3d05..df466ef81ddd 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -23,6 +23,7 @@ #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/idr.h> +#include <linux/uio.h> DEFINE_PER_CPU(int, eventfd_wake_count); @@ -216,32 +217,32 @@ int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *w } EXPORT_SYMBOL_GPL(eventfd_ctx_remove_wait_queue); -static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, - loff_t *ppos) +static ssize_t eventfd_read(struct kiocb *iocb, struct iov_iter *to) { + struct file *file = iocb->ki_filp; struct eventfd_ctx *ctx = file->private_data; - ssize_t res; __u64 ucnt = 0; DECLARE_WAITQUEUE(wait, current); - if (count < sizeof(ucnt)) + if (iov_iter_count(to) < sizeof(ucnt)) return -EINVAL; - spin_lock_irq(&ctx->wqh.lock); - res = -EAGAIN; - if (ctx->count > 0) - res = sizeof(ucnt); - else if (!(file->f_flags & O_NONBLOCK)) { + if (!ctx->count) { + if ((file->f_flags & O_NONBLOCK) || + (iocb->ki_flags & IOCB_NOWAIT)) { + spin_unlock_irq(&ctx->wqh.lock); + return -EAGAIN; + } __add_wait_queue(&ctx->wqh, &wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); - if (ctx->count > 0) { - res = sizeof(ucnt); + if (ctx->count) break; - } if (signal_pending(current)) { - res = -ERESTARTSYS; - break; + __remove_wait_queue(&ctx->wqh, &wait); + __set_current_state(TASK_RUNNING); + spin_unlock_irq(&ctx->wqh.lock); + return -ERESTARTSYS; } spin_unlock_irq(&ctx->wqh.lock); schedule(); @@ -250,17 +251,14 @@ static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, __remove_wait_queue(&ctx->wqh, &wait); __set_current_state(TASK_RUNNING); } - if (likely(res > 0)) { - eventfd_ctx_do_read(ctx, &ucnt); - if (waitqueue_active(&ctx->wqh)) - wake_up_locked_poll(&ctx->wqh, EPOLLOUT); - } + eventfd_ctx_do_read(ctx, &ucnt); + if (waitqueue_active(&ctx->wqh)) + wake_up_locked_poll(&ctx->wqh, EPOLLOUT); spin_unlock_irq(&ctx->wqh.lock); - - if (res > 0 && put_user(ucnt, (__u64 __user *)buf)) + if (unlikely(copy_to_iter(&ucnt, sizeof(ucnt), to) != sizeof(ucnt))) return -EFAULT; - return res; + return sizeof(ucnt); } static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t count, @@ -329,7 +327,7 @@ static const struct file_operations eventfd_fops = { #endif .release = eventfd_release, .poll = eventfd_poll, - .read = eventfd_read, + .read_iter = eventfd_read, .write = eventfd_write, .llseek = noop_llseek, }; @@ -406,6 +404,7 @@ EXPORT_SYMBOL_GPL(eventfd_ctx_fileget); static int do_eventfd(unsigned int count, int flags) { struct eventfd_ctx *ctx; + struct file *file; int fd; /* Check the EFD_* constants for consistency. */ @@ -425,11 +424,24 @@ static int do_eventfd(unsigned int count, int flags) ctx->flags = flags; ctx->id = ida_simple_get(&eventfd_ida, 0, 0, GFP_KERNEL); - fd = anon_inode_getfd("[eventfd]", &eventfd_fops, ctx, - O_RDWR | (flags & EFD_SHARED_FCNTL_FLAGS)); + flags &= EFD_SHARED_FCNTL_FLAGS; + flags |= O_RDWR; + fd = get_unused_fd_flags(flags); if (fd < 0) - eventfd_free_ctx(ctx); + goto err; + + file = anon_inode_getfile("[eventfd]", &eventfd_fops, ctx, flags); + if (IS_ERR(file)) { + put_unused_fd(fd); + fd = PTR_ERR(file); + goto err; + } + file->f_mode |= FMODE_NOWAIT; + fd_install(fd, file); + return fd; +err: + eventfd_free_ctx(ctx); return fd; } |