linux-kernel - [PATCH 07/12] afs: Split afs_validate() so first part can be used under LOOKUP

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Date:   Wed, 15 May 2019 21:59:11 +0100
From:   David Howells <dhowells@...hat.com>
To:     linux-afs@...ts.infradead.org
Cc:     dhowells@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH 07/12] afs: Split afs_validate() so first part can be used
 under LOOKUP_RCU

Split afs_validate() so that the part that decides if the vnode is still
valid can be used under LOOKUP_RCU conditions from afs_d_revalidate().

Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/afs/inode.c    |   37 ++++++++++++++++++++++++-------------
 fs/afs/internal.h |    1 +
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index b644f3d5e4e9..a89948a9dd0d 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -560,23 +560,12 @@ void afs_zap_data(struct afs_vnode *vnode)
 }
 
 /*
- * validate a vnode/inode
- * - there are several things we need to check
- *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
- *     symlink)
- *   - parent dir metadata changed (security changes)
- *   - dentry data changed (write, truncate)
- *   - dentry metadata changed (security changes)
+ * Check the validity of a vnode/inode.
  */
-int afs_validate(struct afs_vnode *vnode, struct key *key)
+bool afs_check_validity(struct afs_vnode *vnode)
 {
 	time64_t now = ktime_get_real_seconds();
 	bool valid;
-	int ret;
-
-	_enter("{v={%llx:%llu} fl=%lx},%x",
-	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
-	       key_serial(key));
 
 	/* Quickly check the callback state.  Ideally, we'd use read_seqbegin
 	 * here, but we have no way to pass the net namespace to the RCU
@@ -605,6 +594,28 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
 	}
 
 	read_sequnlock_excl(&vnode->cb_lock);
+	return valid;
+}
+
+/*
+ * validate a vnode/inode
+ * - there are several things we need to check
+ *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
+ *     symlink)
+ *   - parent dir metadata changed (security changes)
+ *   - dentry data changed (write, truncate)
+ *   - dentry metadata changed (security changes)
+ */
+int afs_validate(struct afs_vnode *vnode, struct key *key)
+{
+	bool valid;
+	int ret;
+
+	_enter("{v={%llx:%llu} fl=%lx},%x",
+	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
+	       key_serial(key));
+
+	valid = afs_check_validity(vnode);
 
 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 		clear_nlink(&vnode->vfs_inode);
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 175501a7cf8b..d19182e9c15c 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1021,6 +1021,7 @@ extern struct inode *afs_iget(struct super_block *, struct key *,
 			      struct afs_cb_interest *,
 			      struct afs_vnode *);
 extern void afs_zap_data(struct afs_vnode *);
+extern bool afs_check_validity(struct afs_vnode *);
 extern int afs_validate(struct afs_vnode *, struct key *);
 extern int afs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int afs_setattr(struct dentry *, struct iattr *);