diff options
Diffstat (limited to 'fs/proc/proc_sysctl.c')
| -rw-r--r-- | fs/proc/proc_sysctl.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index cc9d74a06ff0..49ab74e0bfde 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -540,9 +540,8 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, goto out; } - d_set_d_op(dentry, &proc_sys_dentry_operations); inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); - err = d_splice_alias(inode, dentry); + err = d_splice_alias_ops(inode, dentry, &proc_sys_dentry_operations); out: if (h) @@ -699,9 +698,9 @@ static bool proc_sys_fill_cache(struct file *file, return false; if (d_in_lookup(child)) { struct dentry *res; - d_set_d_op(child, &proc_sys_dentry_operations); inode = proc_sys_make_inode(dir->d_sb, head, table); - res = d_splice_alias(inode, child); + res = d_splice_alias_ops(inode, child, + &proc_sys_dentry_operations); d_lookup_done(child); if (unlikely(res)) { dput(child); @@ -918,17 +917,21 @@ static int proc_sys_compare(const struct dentry *dentry, struct ctl_table_header *head; struct inode *inode; - /* Although proc doesn't have negative dentries, rcu-walk means - * that inode here can be NULL */ - /* AV: can it, indeed? */ - inode = d_inode_rcu(dentry); - if (!inode) - return 1; if (name->len != len) return 1; if (memcmp(name->name, str, len)) return 1; - head = rcu_dereference(PROC_I(inode)->sysctl); + + // false positive is fine here - we'll recheck anyway + if (d_in_lookup(dentry)) + return 0; + + inode = d_inode_rcu(dentry); + // we just might have run into dentry in the middle of __dentry_kill() + if (!inode) + return 1; + + head = READ_ONCE(PROC_I(inode)->sysctl); return !head || !sysctl_is_seen(head); } |