Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull read/write updates from Al Viro:
 "Christoph's fs/read_write.c series - consolidation and cleanups"

* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: remove nfsd_vfs_read
  nfsd: use vfs_iter_read/write
  fs: implement vfs_iter_write using do_iter_write
  fs: implement vfs_iter_read using do_iter_read
  fs: move more code into do_iter_read/do_iter_write
  fs: remove __do_readv_writev
  fs: remove do_compat_readv_writev
  fs: remove do_readv_writev

1 files changed, 91 insertions, 129 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index d591eeed061f..a2cbc8303dae 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -356,46 +356,6 @@ out_putf:
 }
 #endif
 
-ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
-{
-        struct kiocb kiocb;
-        ssize_t ret;
-
-        if (!file->f_op->read_iter)
-                return -EINVAL;
-
-        init_sync_kiocb(&kiocb, file);
-        kiocb.ki_pos = *ppos;
-
-        iter->type |= READ;
-        ret = call_read_iter(file, &kiocb, iter);
-        BUG_ON(ret == -EIOCBQUEUED);
-        if (ret > 0)
-                *ppos = kiocb.ki_pos;
-        return ret;
-}
-EXPORT_SYMBOL(vfs_iter_read);
-
-ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
-{
-        struct kiocb kiocb;
-        ssize_t ret;
-
-        if (!file->f_op->write_iter)
-                return -EINVAL;
-
-        init_sync_kiocb(&kiocb, file);
-        kiocb.ki_pos = *ppos;
-
-        iter->type |= WRITE;
-        ret = call_write_iter(file, &kiocb, iter);
-        BUG_ON(ret == -EIOCBQUEUED);
-        if (ret > 0)
-                *ppos = kiocb.ki_pos;
-        return ret;
-}
-EXPORT_SYMBOL(vfs_iter_write);
-
 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
 {
         struct inode *inode;
@@ -910,86 +870,114 @@ out:
 }
 #endif
 
-static ssize_t __do_readv_writev(int type, struct file *file,
-                                 struct iov_iter *iter, loff_t *pos, int flags)
+static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
+                loff_t *pos, int flags)
 {
         size_t tot_len;
         ssize_t ret = 0;
 
+        if (!(file->f_mode & FMODE_READ))
+                return -EBADF;
+        if (!(file->f_mode & FMODE_CAN_READ))
+                return -EINVAL;
+
         tot_len = iov_iter_count(iter);
         if (!tot_len)
                 goto out;
-        ret = rw_verify_area(type, file, pos, tot_len);
+        ret = rw_verify_area(READ, file, pos, tot_len);
         if (ret < 0)
-                goto out;
-
-        if (type != READ)
-                file_start_write(file);
+                return ret;
 
-        if ((type == READ && file->f_op->read_iter) ||
-            (type == WRITE && file->f_op->write_iter))
-                ret = do_iter_readv_writev(file, iter, pos, type, flags);
+        if (file->f_op->read_iter)
+                ret = do_iter_readv_writev(file, iter, pos, READ, flags);
         else
-                ret = do_loop_readv_writev(file, iter, pos, type, flags);
-
-        if (type != READ)
-                file_end_write(file);
-
+                ret = do_loop_readv_writev(file, iter, pos, READ, flags);
 out:
-        if ((ret + (type == READ)) > 0) {
-                if (type == READ)
-                        fsnotify_access(file);
-                else
-                        fsnotify_modify(file);
-        }
+        if (ret >= 0)
+                fsnotify_access(file);
         return ret;
 }
 
-static ssize_t do_readv_writev(int type, struct file *file,
-                               const struct iovec __user *uvector,
-                               unsigned long nr_segs, loff_t *pos,
-                               int flags)
+ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
+                int flags)
 {
-        struct iovec iovstack[UIO_FASTIOV];
-        struct iovec *iov = iovstack;
-        struct iov_iter iter;
-        ssize_t ret;
+        if (!file->f_op->read_iter)
+                return -EINVAL;
+        return do_iter_read(file, iter, ppos, flags);
+}
+EXPORT_SYMBOL(vfs_iter_read);
+
+static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
+                loff_t *pos, int flags)
+{
+        size_t tot_len;
+        ssize_t ret = 0;
+
+        if (!(file->f_mode & FMODE_WRITE))
+                return -EBADF;
+        if (!(file->f_mode & FMODE_CAN_WRITE))
+                return -EINVAL;
 
-        ret = import_iovec(type, uvector, nr_segs,
-                           ARRAY_SIZE(iovstack), &iov, &iter);
+        tot_len = iov_iter_count(iter);
+        if (!tot_len)
+                return 0;
+        ret = rw_verify_area(WRITE, file, pos, tot_len);
         if (ret < 0)
                 return ret;
 
-        ret = __do_readv_writev(type, file, &iter, pos, flags);
-        kfree(iov);
-
+        file_start_write(file);
+        if (file->f_op->write_iter)
+                ret = do_iter_readv_writev(file, iter, pos, WRITE, flags);
+        else
+                ret = do_loop_readv_writev(file, iter, pos, WRITE, flags);
+        file_end_write(file);
+        if (ret > 0)
+                fsnotify_modify(file);
         return ret;
 }
 
+ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
+                int flags)
+{
+        if (!file->f_op->write_iter)
+                return -EINVAL;
+        return do_iter_write(file, iter, ppos, flags);
+}
+EXPORT_SYMBOL(vfs_iter_write);
+
 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
                   unsigned long vlen, loff_t *pos, int flags)
 {
-        if (!(file->f_mode & FMODE_READ))
-                return -EBADF;
-        if (!(file->f_mode & FMODE_CAN_READ))
-                return -EINVAL;
+        struct iovec iovstack[UIO_FASTIOV];
+        struct iovec *iov = iovstack;
+        struct iov_iter iter;
+        ssize_t ret;
 
-        return do_readv_writev(READ, file, vec, vlen, pos, flags);
-}
+        ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
+        if (ret >= 0) {
+                ret = do_iter_read(file, &iter, pos, flags);
+                kfree(iov);
+        }
 
+        return ret;
+}
 EXPORT_SYMBOL(vfs_readv);
 
 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
                    unsigned long vlen, loff_t *pos, int flags)
 {
-        if (!(file->f_mode & FMODE_WRITE))
-                return -EBADF;
-        if (!(file->f_mode & FMODE_CAN_WRITE))
-                return -EINVAL;
+        struct iovec iovstack[UIO_FASTIOV];
+        struct iovec *iov = iovstack;
+        struct iov_iter iter;
+        ssize_t ret;
 
-        return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
+        ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
+        if (ret >= 0) {
+                ret = do_iter_write(file, &iter, pos, flags);
+                kfree(iov);
+        }
+        return ret;
 }
-
 EXPORT_SYMBOL(vfs_writev);
 
 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
@@ -1137,44 +1125,20 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
 }
 
 #ifdef CONFIG_COMPAT
-
-static ssize_t compat_do_readv_writev(int type, struct file *file,
-                               const struct compat_iovec __user *uvector,
-                               unsigned long nr_segs, loff_t *pos,
-                               int flags)
+static size_t compat_readv(struct file *file,
+                           const struct compat_iovec __user *vec,
+                           unsigned long vlen, loff_t *pos, int flags)
 {
         struct iovec iovstack[UIO_FASTIOV];
         struct iovec *iov = iovstack;
         struct iov_iter iter;
         ssize_t ret;
 
-        ret = compat_import_iovec(type, uvector, nr_segs,
-                                  UIO_FASTIOV, &iov, &iter);
-        if (ret < 0)
-                return ret;
-
-        ret = __do_readv_writev(type, file, &iter, pos, flags);
-        kfree(iov);
-
-        return ret;
-}
-
-static size_t compat_readv(struct file *file,
-                           const struct compat_iovec __user *vec,
-                           unsigned long vlen, loff_t *pos, int flags)
-{
-        ssize_t ret = -EBADF;
-
-        if (!(file->f_mode & FMODE_READ))
-                goto out;
-
-        ret = -EINVAL;
-        if (!(file->f_mode & FMODE_CAN_READ))
-                goto out;
-
-        ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
-
-out:
+        ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
+        if (ret >= 0) {
+                ret = do_iter_read(file, &iter, pos, flags);
+                kfree(iov);
+        }
         if (ret > 0)
                 add_rchar(current, ret);
         inc_syscr(current);
@@ -1270,18 +1234,16 @@ static size_t compat_writev(struct file *file,
                             const struct compat_iovec __user *vec,
                             unsigned long vlen, loff_t *pos, int flags)
 {
-        ssize_t ret = -EBADF;
-
-        if (!(file->f_mode & FMODE_WRITE))
-                goto out;
-
-        ret = -EINVAL;
-        if (!(file->f_mode & FMODE_CAN_WRITE))
-                goto out;
-
-        ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, flags);
+        struct iovec iovstack[UIO_FASTIOV];
+        struct iovec *iov = iovstack;
+        struct iov_iter iter;
+        ssize_t ret;
 
-out:
+        ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
+        if (ret >= 0) {
+                ret = do_iter_write(file, &iter, pos, flags);
+                kfree(iov);
+        }
         if (ret > 0)
                 add_wchar(current, ret);
         inc_syscw(current);