author: Logan Gunthorpe <logang@deltatee.com> 2017-06-15 14:05:20 -0600
committer: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17 15:09:17 +0200
commit: a5d31a3f81c6fb13b381951bf6163444c0257e8b
parent: f5ac3c49ff0b36d9b6a804b4b86efcaf27ba044b
Commit Summary:
Diffstat:
1 file changed, 24 insertions, 11 deletions
diff --git a/fs/char_dev.c b/fs/char_dev.c
index fb8507f521b2..c9d18362e89d 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -59,6 +59,29 @@ void chrdev_show(struct seq_file *f, off_t offset)
#endif /* CONFIG_PROC_FS */
+static int find_dynamic_major(void)
+{
+ int i;
+ struct char_device_struct *cd;
+
+ for (i = ARRAY_SIZE(chrdevs)-1; i > CHRDEV_MAJOR_DYN_END; i--) {
+ if (chrdevs[i] == NULL)
+ return i;
+ }
+
+ for (i = CHRDEV_MAJOR_DYN_EXT_START;
+ i > CHRDEV_MAJOR_DYN_EXT_END; i--) {
+ for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next)
+ if (cd->major == i)
+ break;
+
+ if (cd == NULL || cd->major != i)
+ return i;
+ }
+
+ return -EBUSY;
+}
+
/*
* Register a single major with a specified minor range.
*
@@ -84,22 +107,14 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
mutex_lock(&chrdevs_lock);
- /* temporary */
if (major == 0) {
- for (i = ARRAY_SIZE(chrdevs)-1; i > 0; i--) {
- if (chrdevs[i] == NULL)
- break;
- }
-
- if (i < CHRDEV_MAJOR_DYN_END)
- pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range\n",
- name, i);
-
- if (i == 0) {
- ret = -EBUSY;
+ ret = find_dynamic_major();
+ if (ret < 0) {
+ pr_err("CHRDEV \"%s\" dynamic allocation region is full\n",
+ name);
goto out;
}
- major = i;
+ major = ret;
}
cd->major = major;