[PATCH 04/13] Apparmor: Use simple_start_creating() / simple_done_creating()

NeilBrown
2026-02-04T05:08:38Z

From: NeilBrown <neil@brown.name>

Instead of explicitly locking the parent and performing a look up in
apparmor, use simple_start_creating(), and then simple_done_creating()
to unlock and drop the dentry.

This removes the need to check for an existing entry (as
simple_start_creating() acts like an exclusive create and can return
-EEXIST), simplifies error paths, and keeps dir locking code
centralised.

Signed-off-by: NeilBrown <neil@brown.name>
---
security/apparmor/apparmorfs.c | 38 ++++++++--------------------------
1 file changed, 9 insertions(+), 29 deletions(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 907bd2667e28..7f78c36e6e50 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -282,32 +282,19 @@ static struct dentry *aafs_create(const char *name, umode_t mode,

dir = d_inode(parent);

- inode_lock(dir);
- dentry = lookup_noperm(&QSTR(name), parent);
+ dentry = simple_start_creating(parent, name);
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
- goto fail_lock;
- }
-
- if (d_really_is_positive(dentry)) {
- error = -EEXIST;
- goto fail_dentry;
+ goto fail;
}

error = __aafs_setup_d_inode(dir, dentry, mode, data, link, fops, iops);
+ simple_done_creating(dentry);
if (error)
- goto fail_dentry;
- inode_unlock(dir);
-
- return dentry;
-
-fail_dentry:
- dput(dentry);
-
-fail_lock:
- inode_unlock(dir);
+ goto fail;
+ return 0;
+fail:
simple_release_fs(&aafs_mnt, &aafs_count);
-
return ERR_PTR(error);
}

@@ -2572,8 +2559,7 @@ static int aa_mk_null_file(struct dentry *parent)
if (error)
return error;

- inode_lock(d_inode(parent));
- dentry = lookup_noperm(&QSTR(NULL_FILE_NAME), parent);
+ dentry = simple_start_creating(parent, NULL_FILE_NAME);
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
goto out;
@@ -2581,7 +2567,7 @@ static int aa_mk_null_file(struct dentry *parent)
inode = new_inode(parent->d_inode->i_sb);
if (!inode) {
error = -ENOMEM;
- goto out1;
+ goto out;
}

inode->i_ino = get_next_ino();
@@ -2593,18 +2579,12 @@ static int aa_mk_null_file(struct dentry *parent)
aa_null.dentry = dget(dentry);
aa_null.mnt = mntget(mount);

- error = 0;
-
-out1:
- dput(dentry);
out:
- inode_unlock(d_inode(parent));
+ simple_done_creating(dentry);
simple_release_fs(&mount, &count);
return error;
}

-
-
static const char *policy_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
--
2.50.0.107.gf914562f5916.dirty