Merge tag 'afs-fixes-20190620' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS fixes from David Howells:
 "The in-kernel AFS client has been undergoing testing on opendev.org on
  one of their mirror machines. They are using AFS to hold data that is
  then served via apache, and Ian Wienand had reported seeing oopses,
  spontaneous machine reboots and updates to volumes going missing. This
  patch series appears to have fixed the problem, very probably due to
  patch (2), but it's not 100% certain.

  (1) Fix the printing of the "vnode modified" warning to exclude checks
      on files for which we don't have a callback promise from the
      server (and so don't expect the server to tell us when it
      changes).

      Without this, for every file or directory for which we still have
      an in-core inode that gets changed on the server, we may get a
      message logged when we next look at it. This can happen in bulk
      if, for instance, someone does "vos release" to update a R/O
      volume from a R/W volume and a whole set of files are all changed
      together.

      We only really want to log a message if the file changed and the
      server didn't tell us about it or we failed to track the state
      internally.

  (2) Fix accidental corruption of either afs_vlserver struct objects or
      the the following memory locations (which could hold anything).
      The issue is caused by a union that points to two different
      structs in struct afs_call (to save space in the struct). The call
      cleanup code assumes that it can simply call the cleanup for one
      of those structs if not NULL - when it might be actually pointing
      to the other struct.

      This means that every Volume Location RPC op is going to corrupt
      something.

  (3) Fix an uninitialised spinlock. This isn't too bad, it just causes
      a one-off warning if lockdep is enabled when "vos release" is
      called, but the spinlock still behaves correctly.

  (4) Fix the setting of i_block in the inode. This causes du, for
      example, to produce incorrect results, but otherwise should not be
      dangerous to the kernel"

* tag 'afs-fixes-20190620' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix setting of i_blocks
  afs: Fix uninitialised spinlock afs_volume::cb_break_lock
  afs: Fix vlserver record corruption
  afs: Fix over zealous "vnode modified" warnings

4 files changed, 25 insertions, 19 deletions

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index d441bef72163..915010464572 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -275,9 +275,9 @@ static void afs_break_one_callback(struct afs_server *server,
 			struct afs_super_info *as = AFS_FS_S(cbi->sb);
 			struct afs_volume *volume = as->volume;
 
-			write_lock(&volume->cb_break_lock);
+			write_lock(&volume->cb_v_break_lock);
 			volume->cb_v_break++;
-			write_unlock(&volume->cb_break_lock);
+			write_unlock(&volume->cb_v_break_lock);
 		} else {
 			data.volume = NULL;
 			data.fid = *fid;
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index b42d9d09669c..18a50d4febcf 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -56,6 +56,16 @@ static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *paren
 }
 
 /*
+ * Set the file size and block count.  Estimate the number of 512 bytes blocks
+ * used, rounded up to nearest 1K for consistency with other AFS clients.
+ */
+static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
+{
+	i_size_write(&vnode->vfs_inode, size);
+	vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
+}
+
+/*
  * Initialise an inode from the vnode status.
  */
 static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
@@ -124,12 +134,7 @@ static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
 		return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type);
 	}
 
-	/*
-	 * Estimate 512 bytes  blocks used, rounded up to nearest 1K
-	 * for consistency with other AFS clients.
-	 */
-	inode->i_blocks		= ((i_size_read(inode) + 1023) >> 10) << 1;
-	i_size_write(&vnode->vfs_inode, status->size);
+	afs_set_i_size(vnode, status->size);
 
 	vnode->invalid_before	= status->data_version;
 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
@@ -207,11 +212,13 @@ static void afs_apply_status(struct afs_fs_cursor *fc,
 
 	if (expected_version &&
 	    *expected_version != status->data_version) {
-		kdebug("vnode modified %llx on {%llx:%llu} [exp %llx] %s",
-		       (unsigned long long) status->data_version,
-		       vnode->fid.vid, vnode->fid.vnode,
-		       (unsigned long long) *expected_version,
-		       fc->type ? fc->type->name : "???");
+		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
+			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s\n",
+				vnode->fid.vid, vnode->fid.vnode,
+				(unsigned long long)*expected_version,
+				(unsigned long long)status->data_version,
+				fc->type ? fc->type->name : "???");
+
 		vnode->invalid_before = status->data_version;
 		if (vnode->status.type == AFS_FTYPE_DIR) {
 			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
@@ -230,7 +237,7 @@ static void afs_apply_status(struct afs_fs_cursor *fc,
 
 	if (data_changed) {
 		inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
-		i_size_write(&vnode->vfs_inode, status->size);
+		afs_set_i_size(vnode, status->size);
 	}
 }
 
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 8a67bf741880..7ee63526c6a2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -109,10 +109,8 @@ struct afs_call {
 	struct rxrpc_call	*rxcall;	/* RxRPC call handle */
 	struct key		*key;		/* security for this call */
 	struct afs_net		*net;		/* The network namespace */
-	union {
-		struct afs_server	*server;
-		struct afs_vlserver	*vlserver;
-	};
+	struct afs_server	*server;	/* The fileserver record if fs op (pins ref) */
+	struct afs_vlserver	*vlserver;	/* The vlserver record if vl op */
 	struct afs_cb_interest	*cbi;		/* Callback interest for server used */
 	struct afs_vnode	*lvnode;	/* vnode being locked */
 	void			*request;	/* request data (first part) */
@@ -616,7 +614,7 @@ struct afs_volume {
 	unsigned int		servers_seq;	/* Incremented each time ->servers changes */
 
 	unsigned		cb_v_break;	/* Break-everything counter. */
-	rwlock_t		cb_break_lock;
+	rwlock_t		cb_v_break_lock;
 
 	afs_voltype_t		type;		/* type of volume */
 	short			error;
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 08fdb3951c49..1a414300b654 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -43,6 +43,7 @@ static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
 	atomic_set(&volume->usage, 1);
 	INIT_LIST_HEAD(&volume->proc_link);
 	rwlock_init(&volume->servers_lock);
+	rwlock_init(&volume->cb_v_break_lock);
 	memcpy(volume->name, vldb->name, vldb->name_len + 1);
 
 	slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask);