Remove zpl_revalidate

Fixes openzfs#8774

include/os/linux/zfs/sys/zfs_vfsops.h

@@ -219,6 +219,7 @@ extern int zfsvfs_create(const char *name, boolean_t readony, zfsvfs_t **zfvp);
 extern int zfsvfs_create_impl(zfsvfs_t **zfvp, zfsvfs_t *zfsvfs, objset_t *os);
 extern void zfsvfs_free(zfsvfs_t *zfsvfs);
 extern int zfs_check_global_label(const char *dsname, const char *hexsl);
+extern void zfs_defer_snap_umount(zfsvfs_t *zfsvfs);
 
 extern boolean_t zfs_is_readonly(zfsvfs_t *zfsvfs);
 extern int zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent);

include/os/linux/zfs/sys/zpl.h

@@ -45,7 +45,6 @@ extern const struct inode_operations zpl_inode_operations;
 extern const struct inode_operations zpl_dir_inode_operations;
 extern const struct inode_operations zpl_symlink_inode_operations;
 extern const struct inode_operations zpl_special_inode_operations;
-extern dentry_operations_t zpl_dentry_operations;
 
 /* zpl_file.c */
 extern ssize_t zpl_read_common(struct inode *ip, const char *buf,

include/sys/zfs_znode.h

@@ -272,11 +272,26 @@ do {								\
 #define	ZFS_ENTER(zfsvfs)	ZFS_ENTER_ERROR(zfsvfs, EIO)
 #define	ZPL_ENTER(zfsvfs)	ZFS_ENTER_ERROR(zfsvfs, -EIO)
 
-/* Must be called before exiting the operation. */
+/* Must be called before exiting the vop
+ *
+ */
+#ifdef __linux_
+/*
+ * Automounted snapshots rely on periodic revalidation
+ * to defer snapshots from being automatically unmounted.
+ */
+#define	ZFS_EXIT(zfsvfs)					\
+do {								\
+    if (unlikely(zfsvfs->z_issnap))				\
+	zfs_defer_snap_umount(zfsvfs);				\
+    rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);			\
+} while (0)
+#else
 #define	ZFS_EXIT(zfsvfs)					\
 do {								\
 	rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);		\
 } while (0)
+#endif
 #define	ZPL_EXIT(zfsvfs)	ZFS_EXIT(zfsvfs)
 
 /* Verifies the znode is valid. */

module/os/linux/zfs/zfs_vfsops.c

@@ -1813,6 +1813,18 @@ zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
 atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
 #endif
 
+void
+zfs_defer_snap_umount(zfsvfs_t *zfsvfs)
+{
+	if (time_after(jiffies, zfsvfs->z_snap_defer_time +
+				MAX(zfs_expire_snapshot * HZ / 2, HZ))) {
+		zfsvfs->z_snap_defer_time = jiffies;
+		zfsctl_snapshot_unmount_delay(zfsvfs->z_os->os_spa,
+					    dmu_objset_id(zfsvfs->z_os),
+					    zfs_expire_snapshot);
+	}
+}
+
 int
 zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
 {
@@ -1862,9 +1874,6 @@ zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
 	sb->s_op = &zpl_super_operations;
 	sb->s_xattr = zpl_xattr_handlers;
 	sb->s_export_op = &zpl_export_operations;
-#ifdef HAVE_S_D_OP
-	sb->s_d_op = &zpl_dentry_operations;
-#endif /* HAVE_S_D_OP */
 
 	/* Set features for file system. */
 	zfs_set_fuid_feature(zfsvfs);
@@ -2234,6 +2243,7 @@ zfs_resume_fs(zfsvfs_t *zfsvfs, dsl_dataset_t *ds)
 		zfs_unlinked_drain(zfsvfs);
 	}
 
+	shrink_dcache_sb(zfsvfs->z_parent->z_sb);
 bail:
 	if (err != 0)
 		zfsvfs->z_unmounted = B_TRUE;

module/os/linux/zfs/zpl_inode.c

@@ -70,9 +70,6 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 
 	spin_lock(&dentry->d_lock);
 	dentry->d_time = jiffies;
-#ifndef HAVE_S_D_OP
-	d_set_d_op(dentry, &zpl_dentry_operations);
-#endif /* HAVE_S_D_OP */
 	spin_unlock(&dentry->d_lock);
 
 	if (error) {
@@ -655,59 +652,6 @@ zpl_fallocate(struct inode *ip, int mode, loff_t offset, loff_t len)
 }
 #endif /* HAVE_INODE_FALLOCATE */
 
-static int
-#ifdef HAVE_D_REVALIDATE_NAMEIDATA
-zpl_revalidate(struct dentry *dentry, struct nameidata *nd)
-{
-	unsigned int flags = (nd ? nd->flags : 0);
-#else
-zpl_revalidate(struct dentry *dentry, unsigned int flags)
-{
-#endif /* HAVE_D_REVALIDATE_NAMEIDATA */
-	/* CSTYLED */
-	zfsvfs_t *zfsvfs = dentry->d_sb->s_fs_info;
-	int error;
-
-	if (flags & LOOKUP_RCU)
-		return (-ECHILD);
-
-	/*
-	 * Automounted snapshots rely on periodic dentry revalidation
-	 * to defer snapshots from being automatically unmounted.
-	 */
-	if (zfsvfs->z_issnap) {
-		if (time_after(jiffies, zfsvfs->z_snap_defer_time +
-		    MAX(zfs_expire_snapshot * HZ / 2, HZ))) {
-			zfsvfs->z_snap_defer_time = jiffies;
-			zfsctl_snapshot_unmount_delay(zfsvfs->z_os->os_spa,
-			    dmu_objset_id(zfsvfs->z_os), zfs_expire_snapshot);
-		}
-	}
-
-	/*
-	 * After a rollback negative dentries created before the rollback
-	 * time must be invalidated.  Otherwise they can obscure files which
-	 * are only present in the rolled back dataset.
-	 */
-	if (dentry->d_inode == NULL) {
-		spin_lock(&dentry->d_lock);
-		error = time_before(dentry->d_time, zfsvfs->z_rollback_time);
-		spin_unlock(&dentry->d_lock);
-
-		if (error)
-			return (0);
-	}
-
-	/*
-	 * The dentry may reference a stale inode if a mounted file system
-	 * was rolled back to a point in time where the object didn't exist.
-	 */
-	if (dentry->d_inode && ITOZ(dentry->d_inode)->z_is_stale)
-		return (0);
-
-	return (1);
-}
-
 const struct inode_operations zpl_inode_operations = {
 	.setattr	= zpl_setattr,
 	.getattr	= zpl_getattr,
@@ -820,7 +764,3 @@ const struct inode_operations zpl_special_inode_operations = {
 #endif /* HAVE_GET_ACL | HAVE_CHECK_ACL | HAVE_PERMISSION */
 #endif /* CONFIG_FS_POSIX_ACL */
 };
-
-dentry_operations_t zpl_dentry_operations = {
-	.d_revalidate	= zpl_revalidate,
-};