diff options
| -rw-r--r-- | drivers/char/mem.c | 56 |
1 files changed, 13 insertions, 43 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 917403fe10da..524b707894ef 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -622,53 +622,23 @@ static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); } -static ssize_t read_zero(struct file *file, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) { - size_t written; - - if (!count) - return 0; - - if (!access_ok(VERIFY_WRITE, buf, count)) - return -EFAULT; - - written = 0; - while (count) { - unsigned long unwritten; - size_t chunk = count; + size_t written = 0; + while (iov_iter_count(iter)) { + size_t chunk = iov_iter_count(iter), n; if (chunk > PAGE_SIZE) chunk = PAGE_SIZE; /* Just for latency reasons */ - unwritten = __clear_user(buf, chunk); - written += chunk - unwritten; - if (unwritten) - break; + n = iov_iter_zero(chunk, iter); + if (!n && iov_iter_count(iter)) + return written ? written : -EFAULT; + written += n; if (signal_pending(current)) return written ? written : -ERESTARTSYS; - buf += chunk; - count -= chunk; cond_resched(); } - return written ? written : -EFAULT; -} - -static ssize_t aio_read_zero(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) -{ - size_t written = 0; - unsigned long i; - ssize_t ret; - - for (i = 0; i < nr_segs; i++) { - ret = read_zero(iocb->ki_filp, iov[i].iov_base, iov[i].iov_len, - &pos); - if (ret < 0) - break; - written += ret; - } - - return written ? written : -EFAULT; + return written; } static int mmap_zero(struct file *file, struct vm_area_struct *vma) @@ -738,7 +708,6 @@ static int open_port(struct inode *inode, struct file *filp) #define zero_lseek null_lseek #define full_lseek null_lseek #define write_zero write_null -#define read_full read_zero #define aio_write_zero aio_write_null #define open_mem open_port #define open_kmem open_mem @@ -783,9 +752,9 @@ static const struct file_operations port_fops = { static const struct file_operations zero_fops = { .llseek = zero_lseek, - .read = read_zero, + .read = new_sync_read, .write = write_zero, - .aio_read = aio_read_zero, + .read_iter = read_iter_zero, .aio_write = aio_write_zero, .mmap = mmap_zero, }; @@ -802,7 +771,8 @@ static struct backing_dev_info zero_bdi = { static const struct file_operations full_fops = { .llseek = full_lseek, - .read = read_full, + .read = new_sync_read, + .read_iter = read_iter_zero, .write = write_full, }; |