[PATCH] fs: proc: Clarify warnings for invalid proc dir names

[Joel Savitz]

When one attempts to create a directory in /proc with an invalid name,
such as one in a subdirectory that doesn't exist, one with a name beyond
256 characters, or a reserved name such as '.' or '..', the kernel
throws a warning message that looks like this:

        [ 7913.252558] name 'invalid_name'

This warning message is nearly the same for all invalid cases, including
the removal of a nonexistent directory. This patch clarifies the warning
message and differentiates the invalid creation/removal cases so as to
allow the user to more quickly understand their mistake.

Signed-off-by: Fabrizio D'Angelo <fabrizio_dang...@student.uml.edu>
Signed-off-by: Joel Savitz <jsav...@redhat.com>
---
 fs/proc/generic.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 64e9ee1b129e..df04fd4f02af 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -173,7 +173,7 @@ static int __xlate_proc_name(const char *name, struct 
proc_dir_entry **ret,
                len = next - cp;
                de = pde_subdir_find(de, cp, len);
                if (!de) {
-                       WARN(1, "name '%s'\n", name);
+                       WARN(1, "invalid proc dir name '%s'\n", name);
                        return -ENOENT;
                }
                cp += len + 1;
@@ -386,15 +386,15 @@ static struct proc_dir_entry *__proc_create(struct 
proc_dir_entry **parent,
        qstr.name = fn;
        qstr.len = strlen(fn);
        if (qstr.len == 0 || qstr.len >= 256) {
-               WARN(1, "name len %u\n", qstr.len);
+               WARN(1, "invalid proc dir name len %u\n", qstr.len);
                return NULL;
        }
        if (qstr.len == 1 && fn[0] == '.') {
-               WARN(1, "name '.'\n");
+               WARN(1, "invalid proc dir name '.'\n");
                return NULL;
        }
        if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
-               WARN(1, "name '..'\n");
+               WARN(1, "invalid proc dir name '..'\n");
                return NULL;
        }
        if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
@@ -402,7 +402,7 @@ static struct proc_dir_entry *__proc_create(struct 
proc_dir_entry **parent,
                return NULL;
        }
        if (is_empty_pde(*parent)) {
-               WARN(1, "attempt to add to permanently empty directory");
+               WARN(1, "attempt to add to permanently empty directory in 
proc");
                return NULL;
        }
 
@@ -670,7 +670,7 @@ void remove_proc_entry(const char *name, struct 
proc_dir_entry *parent)
                rb_erase(&de->subdir_node, &parent->subdir);
        write_unlock(&proc_subdir_lock);
        if (!de) {
-               WARN(1, "name '%s'\n", name);
+               WARN(1, "unable to remove nonexistent proc dir '%s'\n", name);
                return;
        }
 
-- 
2.23.0