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>

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 9f99d04..f84cbff 100644 (file)
--- 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;