target/file: merge fd_do_readv() and fd_do_writev()

Those two functions are almost identical so merge them. Noticed this
while fixing the highmem in both cases.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 1fc5825b3912ddad334be7b74566600648bb42d6..b9c88497e8f0d8c989a633bb23605e1f8e1dcff0 100644 (file)
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -216,8 +216,8 @@ static void fd_free_device(struct se_device *dev)
        kfree(fd_dev);
 }
 
-static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
-               u32 sgl_nents)
+static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
+               u32 sgl_nents, int is_write)
 {
        struct se_device *se_dev = cmd->se_dev;
        struct fd_dev *dev = FD_DEV(se_dev);
@@ -241,73 +241,45 @@ static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
 
        old_fs = get_fs();
        set_fs(get_ds());
-       ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
+
+       if (is_write)
+               ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
+       else
+               ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
+
        set_fs(old_fs);
 
        for_each_sg(sgl, sg, sgl_nents, i)
                kunmap(sg_page(sg));
+
        kfree(iov);
-       /*
-        * Return zeros and GOOD status even if the READ did not return
-        * the expected virt_size for struct file w/o a backing struct
-        * block_device.
-        */
-       if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
+
+       if (is_write) {
                if (ret < 0 || ret != cmd->data_length) {
-                       pr_err("vfs_readv() returned %d,"
-                               " expecting %d for S_ISBLK\n", ret,
-                               (int)cmd->data_length);
+                       pr_err("%s() write returned %d\n", __func__, ret);
                        return (ret < 0 ? ret : -EINVAL);
                }
        } else {
-               if (ret < 0) {
-                       pr_err("vfs_readv() returned %d for non"
-                               " S_ISBLK\n", ret);
-                       return ret;
+               /*
+                * Return zeros and GOOD status even if the READ did not return
+                * the expected virt_size for struct file w/o a backing struct
+                * block_device.
+                */
+               if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
+                       if (ret < 0 || ret != cmd->data_length) {
+                               pr_err("%s() returned %d, expecting %u for "
+                                               "S_ISBLK\n", __func__, ret,
+                                               cmd->data_length);
+                               return (ret < 0 ? ret : -EINVAL);
+                       }
+               } else {
+                       if (ret < 0) {
+                               pr_err("%s() returned %d for non S_ISBLK\n",
+                                               __func__, ret);
+                               return ret;
+                       }
                }
        }
-
-       return 1;
-}
-
-static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl,
-               u32 sgl_nents)
-{
-       struct se_device *se_dev = cmd->se_dev;
-       struct fd_dev *dev = FD_DEV(se_dev);
-       struct file *fd = dev->fd_file;
-       struct scatterlist *sg;
-       struct iovec *iov;
-       mm_segment_t old_fs;
-       loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
-       int ret, i = 0;
-
-       iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
-       if (!iov) {
-               pr_err("Unable to allocate fd_do_writev iov[]\n");
-               return -ENOMEM;
-       }
-
-       for_each_sg(sgl, sg, sgl_nents, i) {
-               iov[i].iov_len = sg->length;
-               iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
-       }
-
-       old_fs = get_fs();
-       set_fs(get_ds());
-       ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
-       set_fs(old_fs);
-
-       for_each_sg(sgl, sg, sgl_nents, i)
-               kunmap(sg_page(sg));
-
-       kfree(iov);
-
-       if (ret < 0 || ret != cmd->data_length) {
-               pr_err("vfs_writev() returned %d\n", ret);
-               return (ret < 0 ? ret : -EINVAL);
-       }
-
        return 1;
 }
 
@@ -370,9 +342,9 @@ fd_execute_rw(struct se_cmd *cmd)
         * physical memory addresses to struct iovec virtual memory.
         */
        if (data_direction == DMA_FROM_DEVICE) {
-               ret = fd_do_readv(cmd, sgl, sgl_nents);
+               ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
        } else {
-               ret = fd_do_writev(cmd, sgl, sgl_nents);
+               ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
                /*
                 * Perform implict vfs_fsync_range() for fd_do_writev() ops
                 * for SCSI WRITEs with Forced Unit Access (FUA) set.