Merge tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Add a new knfsd file cache, so that we don't have to open and close
     on each (NFSv2/v3) READ or WRITE. This can speed up read and write
     in some cases. It also replaces our readahead cache.

   - Prevent silent data loss on write errors, by treating write errors
     like server reboots for the purposes of write caching, thus forcing
     clients to resend their writes.

   - Tweak the code that allocates sessions to be more forgiving, so
     that NFSv4.1 mounts are less likely to hang when a server already
     has a lot of clients.

   - Eliminate an arbitrary limit on NFSv4 ACL sizes; they should now be
     limited only by the backend filesystem and the maximum RPC size.

   - Allow the server to enforce use of the correct kerberos credentials
     when a client reclaims state after a reboot.

  And some miscellaneous smaller bugfixes and cleanup"

* tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linux: (34 commits)
  sunrpc: clean up indentation issue
  nfsd: fix nfs read eof detection
  nfsd: Make nfsd_reset_boot_verifier_locked static
  nfsd: degraded slot-count more gracefully as allocation nears exhaustion.
  nfsd: handle drc over-allocation gracefully.
  nfsd: add support for upcall version 2
  nfsd: add a "GetVersion" upcall for nfsdcld
  nfsd: Reset the boot verifier on all write I/O errors
  nfsd: Don't garbage collect files that might contain write errors
  nfsd: Support the server resetting the boot verifier
  nfsd: nfsd_file cache entries should be per net namespace
  nfsd: eliminate an unnecessary acl size limit
  Deprecate nfsd fault injection
  nfsd: remove duplicated include from filecache.c
  nfsd: Fix the documentation for svcxdr_tmpalloc()
  nfsd: Fix up some unused variable warnings
  nfsd: close cached files prior to a REMOVE or RENAME that would replace target
  nfsd: rip out the raparms cache
  nfsd: have nfsd_test_lock use the nfsd_file cache
  nfsd: hook up nfs4_preprocess_stateid_op to the nfsd_file cache
  ...

Author: torvalds

fs/file_table.c

@@ -327,6 +327,7 @@ void flush_delayed_fput(void)
 {
 	delayed_fput(NULL);
 }
+EXPORT_SYMBOL_GPL(flush_delayed_fput);
 
 static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput);
 

fs/locks.c

@@ -212,6 +212,7 @@ struct file_lock_list_struct {
 static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list);
 DEFINE_STATIC_PERCPU_RWSEM(file_rwsem);
 
+
 /*
  * The blocked_hash is used to find POSIX lock loops for deadlock detection.
  * It is protected by blocked_lock_lock.
@@ -1991,6 +1992,64 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
 }
 EXPORT_SYMBOL(generic_setlease);
 
+#if IS_ENABLED(CONFIG_SRCU)
+/*
+ * Kernel subsystems can register to be notified on any attempt to set
+ * a new lease with the lease_notifier_chain. This is used by (e.g.) nfsd
+ * to close files that it may have cached when there is an attempt to set a
+ * conflicting lease.
+ */
+static struct srcu_notifier_head lease_notifier_chain;
+
+static inline void
+lease_notifier_chain_init(void)
+{
+	srcu_init_notifier_head(&lease_notifier_chain);
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+	if (arg != F_UNLCK)
+		srcu_notifier_call_chain(&lease_notifier_chain, arg, lease);
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+	return srcu_notifier_chain_register(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+	srcu_notifier_chain_unregister(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#else /* !IS_ENABLED(CONFIG_SRCU) */
+static inline void
+lease_notifier_chain_init(void)
+{
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#endif /* IS_ENABLED(CONFIG_SRCU) */
+
 /**
  * vfs_setlease        -       sets a lease on an open file
  * @filp:	file pointer
@@ -2011,6 +2070,8 @@ EXPORT_SYMBOL(generic_setlease);
 int
 vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
 {
+	if (lease)
+		setlease_notifier(arg, *lease);
 	if (filp->f_op->setlease)
 		return filp->f_op->setlease(filp, arg, lease, priv);
 	else
@@ -2924,6 +2985,7 @@ static int __init filelock_init(void)
 		INIT_HLIST_HEAD(&fll->hlist);
 	}
 
+	lease_notifier_chain_init();
 	return 0;
 }
 core_initcall(filelock_init);

fs/nfsd/Kconfig

@@ -3,6 +3,7 @@ config NFSD
 	tristate "NFS server support"
 	depends on INET
 	depends on FILE_LOCKING
+	depends on FSNOTIFY
 	select LOCKD
 	select SUNRPC
 	select EXPORTFS
@@ -147,7 +148,7 @@ config NFSD_V4_SECURITY_LABEL
 
 config NFSD_FAULT_INJECTION
 	bool "NFS server manual fault injection"
-	depends on NFSD_V4 && DEBUG_KERNEL && DEBUG_FS
+	depends on NFSD_V4 && DEBUG_KERNEL && DEBUG_FS && BROKEN
 	help
 	  This option enables support for manually injecting faults
 	  into the NFS server.  This is intended to be used for

fs/nfsd/Makefile

@@ -11,7 +11,8 @@ obj-$(CONFIG_NFSD)	+= nfsd.o
 nfsd-y			+= trace.o
 
 nfsd-y 			+= nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \
-			   export.o auth.o lockd.o nfscache.o nfsxdr.o stats.o
+			   export.o auth.o lockd.o nfscache.o nfsxdr.o \
+			   stats.o filecache.o
 nfsd-$(CONFIG_NFSD_FAULT_INJECTION) += fault_inject.o
 nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
 nfsd-$(CONFIG_NFSD_V3)	+= nfs3proc.o nfs3xdr.o

fs/nfsd/acl.h

@@ -39,14 +39,6 @@ struct nfs4_acl;
 struct svc_fh;
 struct svc_rqst;
 
-/*
- * Maximum ACL we'll accept from a client; chosen (somewhat
- * arbitrarily) so that kmalloc'ing the ACL shouldn't require a
- * high-order allocation.  This allows 204 ACEs on x86_64:
- */
-#define NFS4_ACL_MAX ((PAGE_SIZE - sizeof(struct nfs4_acl)) \
-			/ sizeof(struct nfs4_ace))
-
 int nfs4_acl_bytes(int entries);
 int nfs4_acl_get_whotype(char *, u32);
 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who);

fs/nfsd/blocklayout.c

@@ -15,6 +15,7 @@
 
 #include "blocklayoutxdr.h"
 #include "pnfs.h"
+#include "filecache.h"
 
 #define NFSDDBG_FACILITY	NFSDDBG_PNFS
 
@@ -404,7 +405,7 @@ static void
 nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
 {
 	struct nfs4_client *clp = ls->ls_stid.sc_client;
-	struct block_device *bdev = ls->ls_file->f_path.mnt->mnt_sb->s_bdev;
+	struct block_device *bdev = ls->ls_file->nf_file->f_path.mnt->mnt_sb->s_bdev;
 
 	bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
 			nfsd4_scsi_pr_key(clp), 0, true);

fs/nfsd/export.c

@@ -22,6 +22,7 @@
 #include "nfsfh.h"
 #include "netns.h"
 #include "pnfs.h"
+#include "filecache.h"
 
 #define NFSDDBG_FACILITY	NFSDDBG_EXPORT
 
@@ -232,6 +233,17 @@ static struct cache_head *expkey_alloc(void)
 		return NULL;
 }
 
+static void expkey_flush(void)
+{
+	/*
+	 * Take the nfsd_mutex here to ensure that the file cache is not
+	 * destroyed while we're in the middle of flushing.
+	 */
+	mutex_lock(&nfsd_mutex);
+	nfsd_file_cache_purge(current->nsproxy->net_ns);
+	mutex_unlock(&nfsd_mutex);
+}
+
 static const struct cache_detail svc_expkey_cache_template = {
 	.owner		= THIS_MODULE,
 	.hash_size	= EXPKEY_HASHMAX,
@@ -244,6 +256,7 @@ static const struct cache_detail svc_expkey_cache_template = {
 	.init		= expkey_init,
 	.update       	= expkey_update,
 	.alloc		= expkey_alloc,
+	.flush		= expkey_flush,
 };
 
 static int