afs_d_revalidate(): use stable name and parent inode passed by caller

No need to bother with boilerplate for obtaining the latter and for
the former we really should not count upon ->d_name.name remaining
stable under us.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 9780013cd83aa74e7ed362c21a62c47fec0fd75c..e04cffe4beb11fc9d08c857b9b589c2ef0f64b11 100644 (file)
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -607,19 +607,19 @@ static bool afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
  * Do a lookup of a single name in a directory
  * - just returns the FID the dentry name maps to if found
  */
-static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry,
+static int afs_do_lookup_one(struct inode *dir, const struct qstr *name,
                             struct afs_fid *fid, struct key *key,
                             afs_dataversion_t *_dir_version)
 {
        struct afs_super_info *as = dir->i_sb->s_fs_info;
        struct afs_lookup_one_cookie cookie = {
                .ctx.actor = afs_lookup_one_filldir,
-               .name = dentry->d_name,
+               .name = *name,
                .fid.vid = as->volume->vid
        };
        int ret;
 
-       _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
+       _enter("{%lu},{%.*s},", dir->i_ino, name->len, name->name);
 
        /* search the directory */
        ret = afs_dir_iterate(dir, &cookie.ctx, key, _dir_version);
@@ -1052,21 +1052,12 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 /*
  * Check the validity of a dentry under RCU conditions.
  */
-static int afs_d_revalidate_rcu(struct dentry *dentry)
+static int afs_d_revalidate_rcu(struct afs_vnode *dvnode, struct dentry *dentry)
 {
-       struct afs_vnode *dvnode;
-       struct dentry *parent;
-       struct inode *dir;
        long dir_version, de_version;
 
        _enter("%p", dentry);
 
-       /* Check the parent directory is still valid first. */
-       parent = READ_ONCE(dentry->d_parent);
-       dir = d_inode_rcu(parent);
-       if (!dir)
-               return -ECHILD;
-       dvnode = AFS_FS_I(dir);
        if (test_bit(AFS_VNODE_DELETED, &dvnode->flags))
                return -ECHILD;
 
@@ -1097,9 +1088,8 @@ static int afs_d_revalidate_rcu(struct dentry *dentry)
 static int afs_d_revalidate(struct inode *parent_dir, const struct qstr *name,
                            struct dentry *dentry, unsigned int flags)
 {
-       struct afs_vnode *vnode, *dir;
+       struct afs_vnode *vnode, *dir = AFS_FS_I(parent_dir);
        struct afs_fid fid;
-       struct dentry *parent;
        struct inode *inode;
        struct key *key;
        afs_dataversion_t dir_version, invalid_before;
@@ -1107,7 +1097,7 @@ static int afs_d_revalidate(struct inode *parent_dir, const struct qstr *name,
        int ret;
 
        if (flags & LOOKUP_RCU)
-               return afs_d_revalidate_rcu(dentry);
+               return afs_d_revalidate_rcu(dir, dentry);
 
        if (d_really_is_positive(dentry)) {
                vnode = AFS_FS_I(d_inode(dentry));
@@ -1122,14 +1112,9 @@ static int afs_d_revalidate(struct inode *parent_dir, const struct qstr *name,
        if (IS_ERR(key))
                key = NULL;
 
-       /* Hold the parent dentry so we can peer at it */
-       parent = dget_parent(dentry);
-       dir = AFS_FS_I(d_inode(parent));
-
        /* validate the parent directory */
        ret = afs_validate(dir, key);
        if (ret == -ERESTARTSYS) {
-               dput(parent);
                key_put(key);
                return ret;
        }
@@ -1157,7 +1142,7 @@ static int afs_d_revalidate(struct inode *parent_dir, const struct qstr *name,
        afs_stat_v(dir, n_reval);
 
        /* search the directory for this vnode */
-       ret = afs_do_lookup_one(&dir->netfs.inode, dentry, &fid, key, &dir_version);
+       ret = afs_do_lookup_one(&dir->netfs.inode, name, &fid, key, &dir_version);
        switch (ret) {
        case 0:
                /* the filename maps to something */
@@ -1201,22 +1186,19 @@ static int afs_d_revalidate(struct inode *parent_dir, const struct qstr *name,
                goto out_valid;
 
        default:
-               _debug("failed to iterate dir %pd: %d",
-                      parent, ret);
+               _debug("failed to iterate parent %pd2: %d", dentry, ret);
                goto not_found;
        }
 
 out_valid:
        dentry->d_fsdata = (void *)(unsigned long)dir_version;
 out_valid_noupdate:
-       dput(parent);
        key_put(key);
        _leave(" = 1 [valid]");
        return 1;
 
 not_found:
        _debug("dropping dentry %pd2", dentry);
-       dput(parent);
        key_put(key);
 
        _leave(" = 0 [bad]");