From 8a2af06415ef0fc922162503dd18da0d9be7771f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 1 Sep 2017 17:39:09 +0200 Subject: ashmem: switch to ->read_iter And use the proper VFS helper for using the backing file. Also make sure we hold ashmem_lock while updating f_pos to make sure that it's not racy. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- drivers/staging/android/ashmem.c | 29 ++++++++--------------------- 1 file changed, 8 insertions(+), 21 deletions(-) (limited to 'drivers/staging/android') diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c index 6ba270e0494d..0f695df14c9d 100644 --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -294,19 +294,9 @@ static int ashmem_release(struct inode *ignored, struct file *file) return 0; } -/** - * ashmem_read() - Reads a set of bytes from an Ashmem-enabled file - * @file: The associated backing file. - * @buf: The buffer of data being written to - * @len: The number of bytes being read - * @pos: The position of the first byte to read. - * - * Return: 0 if successful, or another return code if not. - */ -static ssize_t ashmem_read(struct file *file, char __user *buf, - size_t len, loff_t *pos) +static ssize_t ashmem_read_iter(struct kiocb *iocb, struct iov_iter *iter) { - struct ashmem_area *asma = file->private_data; + struct ashmem_area *asma = iocb->ki_filp->private_data; int ret = 0; mutex_lock(&ashmem_mutex); @@ -320,20 +310,17 @@ static ssize_t ashmem_read(struct file *file, char __user *buf, goto out_unlock; } - mutex_unlock(&ashmem_mutex); - /* * asma and asma->file are used outside the lock here. We assume * once asma->file is set it will never be changed, and will not * be destroyed until all references to the file are dropped and * ashmem_release is called. */ - ret = __vfs_read(asma->file, buf, len, pos); - if (ret >= 0) - /** Update backing file pos, since f_ops->read() doesn't */ - asma->file->f_pos = *pos; - return ret; - + mutex_unlock(&ashmem_mutex); + ret = vfs_iter_read(asma->file, iter, &iocb->ki_pos, 0); + mutex_lock(&ashmem_mutex); + if (ret > 0) + asma->file->f_pos = iocb->ki_pos; out_unlock: mutex_unlock(&ashmem_mutex); return ret; @@ -834,7 +821,7 @@ static const struct file_operations ashmem_fops = { .owner = THIS_MODULE, .open = ashmem_open, .release = ashmem_release, - .read = ashmem_read, + .read_iter = ashmem_read_iter, .llseek = ashmem_llseek, .mmap = ashmem_mmap, .unlocked_ioctl = ashmem_ioctl, -- cgit v1.2.3-59-g8ed1b