[PATCH v2 16/20] nfs{,4}_lookup_validate(): use stable parent inode passed by caller

Al Viro
2025-01-16T05:23:21Z

we can't kill __nfs_lookup_revalidate() completely, but ->d_parent boilerplate
in it is gone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/nfs/dir.c | 43 +++++++++++++------------------------------
1 file changed, 13 insertions(+), 30 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 9910d9796f4c..c28983ee75ca 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1732,8 +1732,8 @@ static int nfs_lookup_revalidate_dentry(struct inode *dir,
* cached dentry and do a new lookup.
*/
static int
-nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
- unsigned int flags)
+nfs_do_lookup_revalidate(struct inode *dir, const struct qstr *name,
+ struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
int error = 0;
@@ -1785,39 +1785,26 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
}

static int
-__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags,
- int (*reval)(struct inode *, struct dentry *, unsigned int))
+__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
{
- struct dentry *parent;
- struct inode *dir;
- int ret;
-
if (flags & LOOKUP_RCU) {
if (dentry->d_fsdata == NFS_FSDATA_BLOCKED)
return -ECHILD;
- parent = READ_ONCE(dentry->d_parent);
- dir = d_inode_rcu(parent);
- if (!dir)
- return -ECHILD;
- ret = reval(dir, dentry, flags);
- if (parent != READ_ONCE(dentry->d_parent))
- return -ECHILD;
} else {
/* Wait for unlink to complete - see unblock_revalidate() */
wait_var_event(&dentry->d_fsdata,
smp_load_acquire(&dentry->d_fsdata)
!= NFS_FSDATA_BLOCKED);
- parent = dget_parent(dentry);
- ret = reval(d_inode(parent), dentry, flags);
- dput(parent);
}
- return ret;
+ return 0;
}

static int nfs_lookup_revalidate(struct inode *dir, const struct qstr *name,
struct dentry *dentry, unsigned int flags)
{
- return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate);
+ if (__nfs_lookup_revalidate(dentry, flags))
+ return -ECHILD;
+ return nfs_do_lookup_revalidate(dir, name, dentry, flags);
}

static void block_revalidate(struct dentry *dentry)
@@ -2216,11 +2203,14 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
EXPORT_SYMBOL_GPL(nfs_atomic_open);

static int
-nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
- unsigned int flags)
+nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name,
+ struct dentry *dentry, unsigned int flags)
{
struct inode *inode;

+ if (__nfs_lookup_revalidate(dentry, flags))
+ return -ECHILD;
+
trace_nfs_lookup_revalidate_enter(dir, dentry, flags);

if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
@@ -2259,14 +2249,7 @@ nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags);

full_reval:
- return nfs_do_lookup_revalidate(dir, dentry, flags);
-}
-
-static int nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name,
- struct dentry *dentry, unsigned int flags)
-{
- return __nfs_lookup_revalidate(dentry, flags,
- nfs4_do_lookup_revalidate);
+ return nfs_do_lookup_revalidate(dir, name, dentry, flags);
}

#endif /* CONFIG_NFSV4 */
--
2.39.5