replace checking for ->read/->aio_read presence with check in ->f_mode

Since we are about to introduce new methods (read_iter/write_iter), the
tests in a bunch of places would have to grow inconveniently.  Check
once (at open() time) and store results in ->f_mode as FMODE_CAN_READ
and FMODE_CAN_WRITE resp.  It might end up being a temporary measure -
once everything switches from ->aio_{read,write} to ->{read,write}_iter
it might make sense to return to open-coded checks.  We'll see...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 7 insertions, 7 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 31c6efa43183..d29d2a361d2c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -396,7 +396,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 
         if (!(file->f_mode & FMODE_READ))
                 return -EBADF;
-        if (!file->f_op->read && !file->f_op->aio_read)
+        if (!(file->f_mode & FMODE_CAN_READ))
                 return -EINVAL;
         if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
                 return -EFAULT;
@@ -445,7 +445,7 @@ ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t
         const char __user *p;
         ssize_t ret;
 
-        if (!file->f_op->write && !file->f_op->aio_write)
+        if (!(file->f_mode & FMODE_CAN_WRITE))
                 return -EINVAL;
 
         old_fs = get_fs();
@@ -472,7 +472,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
 
         if (!(file->f_mode & FMODE_WRITE))
                 return -EBADF;
-        if (!file->f_op->write && !file->f_op->aio_write)
+        if (!(file->f_mode & FMODE_CAN_WRITE))
                 return -EINVAL;
         if (unlikely(!access_ok(VERIFY_READ, buf, count)))
                 return -EFAULT;
@@ -785,7 +785,7 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 {
         if (!(file->f_mode & FMODE_READ))
                 return -EBADF;
-        if (!file->f_op->aio_read && !file->f_op->read)
+        if (!(file->f_mode & FMODE_CAN_READ))
                 return -EINVAL;
 
         return do_readv_writev(READ, file, vec, vlen, pos);
@@ -798,7 +798,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 {
         if (!(file->f_mode & FMODE_WRITE))
                 return -EBADF;
-        if (!file->f_op->aio_write && !file->f_op->write)
+        if (!(file->f_mode & FMODE_CAN_WRITE))
                 return -EINVAL;
 
         return do_readv_writev(WRITE, file, vec, vlen, pos);
@@ -964,7 +964,7 @@ static size_t compat_readv(struct file *file,
                 goto out;
 
         ret = -EINVAL;
-        if (!file->f_op->aio_read && !file->f_op->read)
+        if (!(file->f_mode & FMODE_CAN_READ))
                 goto out;
 
         ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
@@ -1041,7 +1041,7 @@ static size_t compat_writev(struct file *file,
                 goto out;
 
         ret = -EINVAL;
-        if (!file->f_op->aio_write && !file->f_op->write)
+        if (!(file->f_mode & FMODE_CAN_WRITE))
                 goto out;
 
         ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);