fs: move permission hook out of do_iter_write()

[thirdparty/kernel/linux.git] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index 4771701c896badcbc7dc2e3f1f528dc9026864ad..d08d0a3ff7dec72a6e7ca1e2d79a2391f6e18797 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -838,12 +838,14 @@ ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
 }
 EXPORT_SYMBOL(vfs_iter_read);
 
-static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
-               loff_t *pos, rwf_t flags)
+ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
+                           struct iov_iter *iter)
 {
        size_t tot_len;
        ssize_t ret = 0;
 
+       if (!file->f_op->write_iter)
+               return -EINVAL;
        if (!(file->f_mode & FMODE_WRITE))
                return -EBADF;
        if (!(file->f_mode & FMODE_CAN_WRITE))
@@ -852,54 +854,47 @@ static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
        tot_len = iov_iter_count(iter);
        if (!tot_len)
                return 0;
-       ret = rw_verify_area(WRITE, file, pos, tot_len);
+       ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
        if (ret < 0)
                return ret;
 
-       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);
+       ret = call_write_iter(file, iocb, iter);
        if (ret > 0)
                fsnotify_modify(file);
+
        return ret;
 }
+EXPORT_SYMBOL(vfs_iocb_iter_write);
 
-ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
-                           struct iov_iter *iter)
+ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
+                      rwf_t flags)
 {
        size_t tot_len;
-       ssize_t ret = 0;
+       ssize_t ret;
 
-       if (!file->f_op->write_iter)
-               return -EINVAL;
        if (!(file->f_mode & FMODE_WRITE))
                return -EBADF;
        if (!(file->f_mode & FMODE_CAN_WRITE))
                return -EINVAL;
+       if (!file->f_op->write_iter)
+               return -EINVAL;
 
        tot_len = iov_iter_count(iter);
        if (!tot_len)
                return 0;
-       ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
+
+       ret = rw_verify_area(WRITE, file, ppos, tot_len);
        if (ret < 0)
                return ret;
 
-       ret = call_write_iter(file, iocb, iter);
+       file_start_write(file);
+       ret = do_iter_readv_writev(file, iter, ppos, WRITE, flags);
        if (ret > 0)
                fsnotify_modify(file);
+       file_end_write(file);
 
        return ret;
 }
-EXPORT_SYMBOL(vfs_iocb_iter_write);
-
-ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
-               rwf_t flags)
-{
-       if (!file->f_op->write_iter)
-               return -EINVAL;
-       return do_iter_write(file, iter, ppos, flags);
-}
 EXPORT_SYMBOL(vfs_iter_write);
 
 static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
@@ -920,20 +915,42 @@ static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 }
 
 static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
-                  unsigned long vlen, loff_t *pos, rwf_t flags)
+                         unsigned long vlen, loff_t *pos, rwf_t flags)
 {
        struct iovec iovstack[UIO_FASTIOV];
        struct iovec *iov = iovstack;
        struct iov_iter iter;
-       ssize_t ret;
+       size_t tot_len;
+       ssize_t ret = 0;
 
-       ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
-       if (ret >= 0) {
-               file_start_write(file);
-               ret = do_iter_write(file, &iter, pos, flags);
-               file_end_write(file);
-               kfree(iov);
-       }
+       if (!(file->f_mode & FMODE_WRITE))
+               return -EBADF;
+       if (!(file->f_mode & FMODE_CAN_WRITE))
+               return -EINVAL;
+
+       ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov,
+                          &iter);
+       if (ret < 0)
+               return ret;
+
+       tot_len = iov_iter_count(&iter);
+       if (!tot_len)
+               goto out;
+
+       ret = rw_verify_area(WRITE, file, pos, tot_len);
+       if (ret < 0)
+               goto out;
+
+       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);
+       if (ret > 0)
+               fsnotify_modify(file);
+       file_end_write(file);
+out:
+       kfree(iov);
        return ret;
 }