@@ -79,7 +79,6 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
{
struct ctl_table_header *head = grab_header(dir);
struct ctl_table *table = PROC_I(dir)->sysctl_entry;
- struct ctl_table_header *h = NULL;
struct qstr *name = &dentry->d_name;
struct ctl_table *p;
struct inode *inode;
@@ -97,10 +96,11 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
p = find_in_table(table, name);
if (!p) {
- for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) {
- if (h->attached_to != table)
+ sysctl_head_finish(head);
+ for (head = sysctl_head_next(NULL); head; head = sysctl_head_next(head)) {
+ if (head->attached_to != table)
continue;
- p = find_in_table(h->attached_by, name);
+ p = find_in_table(head->attached_by, name);
if (p)
break;
}
@@ -110,9 +110,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
goto out;
err = ERR_PTR(-ENOMEM);
- inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);
- if (h)
- sysctl_head_finish(h);
+ inode = proc_sys_make_inode(dir->i_sb, head, p);
if (!inode)
goto out;
@@ -243,7 +241,6 @@ static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir)
struct inode *inode = dentry->d_inode;
struct ctl_table_header *head = grab_header(inode);
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
- struct ctl_table_header *h = NULL;
unsigned long pos;
int ret = -EINVAL;
@@ -277,14 +274,13 @@ static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir)
if (ret)
goto out;
- for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) {
- if (h->attached_to != table)
+ sysctl_head_finish(head);
+ for (head = sysctl_head_next(NULL); head; head = sysctl_head_next(head)) {
+ if (head->attached_to != table)
continue;
- ret = scan(h, h->attached_by, &pos, filp, dirent, filldir);
- if (ret) {
- sysctl_head_finish(h);
+ ret = scan(head, head->attached_by, &pos, filp, dirent, filldir);
+ if (ret)
break;
- }
}
ret = 1;
out:
The current code works fine, and is actually not buggy but it does prevent enabling the use of lockdep to check refcounting vs lock holding ordering problems. So since we can ensure that we are only hold a single sysctl_head at a time. Allowing lockdep to complain. Signed-off-by: Eric Biederman <ebiederm@aristanetworks.com> --- fs/proc/proc_sysctl.c | 24 ++++++++++-------------- 1 files changed, 10 insertions(+), 14 deletions(-)