[PATCH 2/5] procfs: factor out inode revalidation work from pid_revalidation

From: jeffm
Date: Mon Apr 23 2018 - 22:21:51 EST


From: Jeff Mahoney <jeffm@xxxxxxxx>

Subsequent patches will introduce their own d_revalidate callbacks and we
won't want to get the task multiple times.

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
---
fs/proc/base.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index e9876a89a5ad..e7ca45504a5f 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1802,14 +1802,24 @@ int pid_getattr(const struct path *path, struct kstat *stat,

/* dentry stuff */

+
+/*
+ * Rewrite the inode's ownerships here because the owning task may have
+ * performed a setuid(), etc.
+ */
+static void pid_revalidate_inode(struct inode *inode, struct task_struct *task)
+{
+ task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
+
+ inode->i_mode &= ~(S_ISUID | S_ISGID);
+ security_task_to_inode(task, inode);
+}
+
/*
* Exceptional case: normally we are not allowed to unhash a busy
* directory. In this case, however, we can do it - no aliasing problems
* due to the way we treat inodes.
*
- * Rewrite the inode's ownerships here because the owning task may have
- * performed a setuid(), etc.
- *
*/
int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
@@ -1823,10 +1833,7 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
task = get_proc_task(inode);

if (task) {
- task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
-
- inode->i_mode &= ~(S_ISUID | S_ISGID);
- security_task_to_inode(task, inode);
+ pid_revalidate_inode(inode, task);
put_task_struct(task);
return 1;
}
--
2.12.3