delousing target_core_file a bit

* set_fs(KERNEL_DS) + getname() is probably the weirdest implementation
of strdup() I've seen.  Especially since they don't to copy it at all...
* filp_open() never returns NULL; it's ERR_PTR(-E...) on failure.
* file->f_dentry is never going to be NULL, TYVM.
* match_strdup() + snprintf() + kfree() is a bloody weird way to spell
match_strlcpy().

Pox on cargo-cult programmers...

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

1 files changed, 5 insertions, 27 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 9f99d0404908..f84cbff83bcd 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -109,46 +109,29 @@ static struct se_device *fd_create_virtdevice(
         struct se_subsystem_dev *se_dev,
         void *p)
 {
-        char *dev_p = NULL;
         struct se_device *dev;
         struct se_dev_limits dev_limits;
         struct queue_limits *limits;
         struct fd_dev *fd_dev = p;
         struct fd_host *fd_host = hba->hba_ptr;
-        mm_segment_t old_fs;
         struct file *file;
         struct inode *inode = NULL;
         int dev_flags = 0, flags, ret = -EINVAL;
 
         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 
-        old_fs = get_fs();
-        set_fs(get_ds());
-        dev_p = getname(fd_dev->fd_dev_name);
-        set_fs(old_fs);
-
-        if (IS_ERR(dev_p)) {
-                pr_err("getname(%s) failed: %lu\n",
-                        fd_dev->fd_dev_name, IS_ERR(dev_p));
-                ret = PTR_ERR(dev_p);
-                goto fail;
-        }
         /*
          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
          * of pure timestamp updates.
          */
         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 
-        file = filp_open(dev_p, flags, 0600);
+        file = filp_open(fd_dev->fd_dev_name, flags, 0600);
         if (IS_ERR(file)) {
-                pr_err("filp_open(%s) failed\n", dev_p);
+                pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
                 ret = PTR_ERR(file);
                 goto fail;
         }
-        if (!file || !file->f_dentry) {
-                pr_err("filp_open(%s) failed\n", dev_p);
-                goto fail;
-        }
         fd_dev->fd_file = file;
         /*
          * If using a block backend with this struct file, we extract
@@ -212,14 +195,12 @@ static struct se_device *fd_create_virtdevice(
                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 
-        putname(dev_p);
         return dev;
 fail:
         if (fd_dev->fd_file) {
                 filp_close(fd_dev->fd_file, NULL);
                 fd_dev->fd_file = NULL;
         }
-        putname(dev_p);
         return ERR_PTR(ret);
 }
 
@@ -448,14 +429,11 @@ static ssize_t fd_set_configfs_dev_params(
                 token = match_token(ptr, tokens, args);
                 switch (token) {
                 case Opt_fd_dev_name:
-                        arg_p = match_strdup(&args[0]);
-                        if (!arg_p) {
-                                ret = -ENOMEM;
+                        if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
+                                FD_MAX_DEV_NAME) == 0) {
+                                ret = -EINVAL;
                                 break;
                         }
-                        snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
-                                        "%s", arg_p);
-                        kfree(arg_p);
                         pr_debug("FILEIO: Referencing Path: %s\n",
                                         fd_dev->fd_dev_name);
                         fd_dev->fbd_flags |= FBDF_HAS_PATH;