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>

1 files changed, 32 insertions, 60 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 1fc5825b3912..b9c88497e8f0 100644
--- 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.