Merge tag 'ceph-for-6.17-rc6' of https://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "A fix for a race condition around r_parent tracking that took a long
  time to track down from Alex and some fixes for potential crashes on
  accessing invalid memory from Max and myself.

  All marked for stable"

* tag 'ceph-for-6.17-rc6' of https://github.com/ceph/ceph-client:
  libceph: fix invalid accesses to ceph_connection_v1_info
  ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error
  ceph: always call ceph_shift_unused_folios_left()
  ceph: fix race condition where r_parent becomes stale before sending message
  ceph: fix race condition validating r_parent before applying state
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 8b202d7..322ed26 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1264,7 +1264,9 @@ static inline int move_dirty_folio_in_page_array(struct address_space *mapping,
 								0,
 								gfp_flags);
 		if (IS_ERR(pages[index])) {
-			if (PTR_ERR(pages[index]) == -EINVAL) {
+			int err = PTR_ERR(pages[index]);
+
+			if (err == -EINVAL) {
 				pr_err_client(cl, "inode->i_blkbits=%hhu\n",
 						inode->i_blkbits);
 			}
@@ -1273,7 +1275,7 @@ static inline int move_dirty_folio_in_page_array(struct address_space *mapping,
 			BUG_ON(ceph_wbc->locked_pages == 0);
 
 			pages[index] = NULL;
-			return PTR_ERR(pages[index]);
+			return err;
 		}
 	} else {
 		pages[index] = &folio->page;
@@ -1687,6 +1689,7 @@ static int ceph_writepages_start(struct address_space *mapping,
 
 process_folio_batch:
 		rc = ceph_process_folio_batch(mapping, wbc, &ceph_wbc);
+		ceph_shift_unused_folios_left(&ceph_wbc.fbatch);
 		if (rc)
 			goto release_folios;
 
@@ -1695,8 +1698,6 @@ static int ceph_writepages_start(struct address_space *mapping,
 			goto release_folios;
 
 		if (ceph_wbc.processed_in_fbatch) {
-			ceph_shift_unused_folios_left(&ceph_wbc.fbatch);
-
 			if (folio_batch_count(&ceph_wbc.fbatch) == 0 &&
 			    ceph_wbc.locked_pages < ceph_wbc.max_pages) {
 				doutc(cl, "reached end fbatch, trying for more\n");
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index fdd404f..f3fe786 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -55,8 +55,6 @@ static int mdsc_show(struct seq_file *s, void *p)
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	struct ceph_mds_request *req;
 	struct rb_node *rp;
-	int pathlen = 0;
-	u64 pathbase;
 	char *path;
 
 	mutex_lock(&mdsc->mutex);
@@ -81,8 +79,8 @@ static int mdsc_show(struct seq_file *s, void *p)
 		if (req->r_inode) {
 			seq_printf(s, " #%llx", ceph_ino(req->r_inode));
 		} else if (req->r_dentry) {
-			path = ceph_mdsc_build_path(mdsc, req->r_dentry, &pathlen,
-						    &pathbase, 0);
+			struct ceph_path_info path_info;
+			path = ceph_mdsc_build_path(mdsc, req->r_dentry, &path_info, 0);
 			if (IS_ERR(path))
 				path = NULL;
 			spin_lock(&req->r_dentry->d_lock);
@@ -91,7 +89,7 @@ static int mdsc_show(struct seq_file *s, void *p)
 				   req->r_dentry,
 				   path ? path : "");
 			spin_unlock(&req->r_dentry->d_lock);
-			ceph_mdsc_free_path(path, pathlen);
+			ceph_mdsc_free_path_info(&path_info);
 		} else if (req->r_path1) {
 			seq_printf(s, " #%llx/%s", req->r_ino1.ino,
 				   req->r_path1);
@@ -100,8 +98,8 @@ static int mdsc_show(struct seq_file *s, void *p)
 		}
 
 		if (req->r_old_dentry) {
-			path = ceph_mdsc_build_path(mdsc, req->r_old_dentry, &pathlen,
-						    &pathbase, 0);
+			struct ceph_path_info path_info;
+			path = ceph_mdsc_build_path(mdsc, req->r_old_dentry, &path_info, 0);
 			if (IS_ERR(path))
 				path = NULL;
 			spin_lock(&req->r_old_dentry->d_lock);
@@ -111,7 +109,7 @@ static int mdsc_show(struct seq_file *s, void *p)
 				   req->r_old_dentry,
 				   path ? path : "");
 			spin_unlock(&req->r_old_dentry->d_lock);
-			ceph_mdsc_free_path(path, pathlen);
+			ceph_mdsc_free_path_info(&path_info);
 		} else if (req->r_path2 && req->r_op != CEPH_MDS_OP_SYMLINK) {
 			if (req->r_ino2.ino)
 				seq_printf(s, " #%llx/%s", req->r_ino2.ino,
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 8478e7e..32973c6 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1271,10 +1271,8 @@ static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
 
 	/* If op failed, mark everyone involved for errors */
 	if (result) {
-		int pathlen = 0;
-		u64 base = 0;
-		char *path = ceph_mdsc_build_path(mdsc, dentry, &pathlen,
-						  &base, 0);
+		struct ceph_path_info path_info = {0};
+		char *path = ceph_mdsc_build_path(mdsc, dentry, &path_info, 0);
 
 		/* mark error on parent + clear complete */
 		mapping_set_error(req->r_parent->i_mapping, result);
@@ -1288,8 +1286,8 @@ static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
 		mapping_set_error(req->r_old_inode->i_mapping, result);
 
 		pr_warn_client(cl, "failure path=(%llx)%s result=%d!\n",
-			       base, IS_ERR(path) ? "<<bad>>" : path, result);
-		ceph_mdsc_free_path(path, pathlen);
+			       path_info.vino.ino, IS_ERR(path) ? "<<bad>>" : path, result);
+		ceph_mdsc_free_path_info(&path_info);
 	}
 out:
 	iput(req->r_old_inode);
@@ -1347,8 +1345,6 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	int err = -EROFS;
 	int op;
 	char *path;
-	int pathlen;
-	u64 pathbase;
 
 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
 		/* rmdir .snap/foo is RMSNAP */
@@ -1367,14 +1363,15 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	if (!dn) {
 		try_async = false;
 	} else {
-		path = ceph_mdsc_build_path(mdsc, dn, &pathlen, &pathbase, 0);
+		struct ceph_path_info path_info;
+		path = ceph_mdsc_build_path(mdsc, dn, &path_info, 0);
 		if (IS_ERR(path)) {
 			try_async = false;
 			err = 0;
 		} else {
 			err = ceph_mds_check_access(mdsc, path, MAY_WRITE);
 		}
-		ceph_mdsc_free_path(path, pathlen);
+		ceph_mdsc_free_path_info(&path_info);
 		dput(dn);
 
 		/* For none EACCES cases will let the MDS do the mds auth check */
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index c02f100..978acd3 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -368,8 +368,6 @@ int ceph_open(struct inode *inode, struct file *file)
 	int flags, fmode, wanted;
 	struct dentry *dentry;
 	char *path;
-	int pathlen;
-	u64 pathbase;
 	bool do_sync = false;
 	int mask = MAY_READ;
 
@@ -399,14 +397,15 @@ int ceph_open(struct inode *inode, struct file *file)
 	if (!dentry) {
 		do_sync = true;
 	} else {
-		path = ceph_mdsc_build_path(mdsc, dentry, &pathlen, &pathbase, 0);
+		struct ceph_path_info path_info;
+		path = ceph_mdsc_build_path(mdsc, dentry, &path_info, 0);
 		if (IS_ERR(path)) {
 			do_sync = true;
 			err = 0;
 		} else {
 			err = ceph_mds_check_access(mdsc, path, mask);
 		}
-		ceph_mdsc_free_path(path, pathlen);
+		ceph_mdsc_free_path_info(&path_info);
 		dput(dentry);
 
 		/* For none EACCES cases will let the MDS do the mds auth check */
@@ -614,15 +613,13 @@ static void ceph_async_create_cb(struct ceph_mds_client *mdsc,
 	mapping_set_error(req->r_parent->i_mapping, result);
 
 	if (result) {
-		int pathlen = 0;
-		u64 base = 0;
-		char *path = ceph_mdsc_build_path(mdsc, req->r_dentry, &pathlen,
-						  &base, 0);
+		struct ceph_path_info path_info = {0};
+		char *path = ceph_mdsc_build_path(mdsc, req->r_dentry, &path_info, 0);
 
 		pr_warn_client(cl,
 			"async create failure path=(%llx)%s result=%d!\n",
-			base, IS_ERR(path) ? "<<bad>>" : path, result);
-		ceph_mdsc_free_path(path, pathlen);
+			path_info.vino.ino, IS_ERR(path) ? "<<bad>>" : path, result);
+		ceph_mdsc_free_path_info(&path_info);
 
 		ceph_dir_clear_complete(req->r_parent);
 		if (!d_unhashed(dentry))
@@ -791,8 +788,6 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 	int mask;
 	int err;
 	char *path;
-	int pathlen;
-	u64 pathbase;
 
 	doutc(cl, "%p %llx.%llx dentry %p '%pd' %s flags %d mode 0%o\n",
 	      dir, ceph_vinop(dir), dentry, dentry,
@@ -814,7 +809,8 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 	if (!dn) {
 		try_async = false;
 	} else {
-		path = ceph_mdsc_build_path(mdsc, dn, &pathlen, &pathbase, 0);
+		struct ceph_path_info path_info;
+		path = ceph_mdsc_build_path(mdsc, dn, &path_info, 0);
 		if (IS_ERR(path)) {
 			try_async = false;
 			err = 0;
@@ -826,7 +822,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 				mask |= MAY_WRITE;
 			err = ceph_mds_check_access(mdsc, path, mask);
 		}
-		ceph_mdsc_free_path(path, pathlen);
+		ceph_mdsc_free_path_info(&path_info);
 		dput(dn);
 
 		/* For none EACCES cases will let the MDS do the mds auth check */
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index fc54307..f670254 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -55,6 +55,52 @@ static int ceph_set_ino_cb(struct inode *inode, void *data)
 	return 0;
 }
 
+/*
+ * Check if the parent inode matches the vino from directory reply info
+ */
+static inline bool ceph_vino_matches_parent(struct inode *parent,
+					    struct ceph_vino vino)
+{
+	return ceph_ino(parent) == vino.ino && ceph_snap(parent) == vino.snap;
+}
+
+/*
+ * Validate that the directory inode referenced by @req->r_parent matches the
+ * inode number and snapshot id contained in the reply's directory record.  If
+ * they do not match – which can theoretically happen if the parent dentry was
+ * moved between the time the request was issued and the reply arrived – fall
+ * back to looking up the correct inode in the inode cache.
+ *
+ * A reference is *always* returned.  Callers that receive a different inode
+ * than the original @parent are responsible for dropping the extra reference
+ * once the reply has been processed.
+ */
+static struct inode *ceph_get_reply_dir(struct super_block *sb,
+					struct inode *parent,
+					struct ceph_mds_reply_info_parsed *rinfo)
+{
+	struct ceph_vino vino;
+
+	if (unlikely(!rinfo->diri.in))
+		return parent; /* nothing to compare against */
+
+	/* If we didn't have a cached parent inode to begin with, just bail out. */
+	if (!parent)
+		return NULL;
+
+	vino.ino  = le64_to_cpu(rinfo->diri.in->ino);
+	vino.snap = le64_to_cpu(rinfo->diri.in->snapid);
+
+	if (likely(ceph_vino_matches_parent(parent, vino)))
+		return parent; /* matches – use the original reference */
+
+	/* Mismatch – this should be rare.  Emit a WARN and obtain the correct inode. */
+	WARN_ONCE(1, "ceph: reply dir mismatch (parent valid %llx.%llx reply %llx.%llx)\n",
+		  ceph_ino(parent), ceph_snap(parent), vino.ino, vino.snap);
+
+	return ceph_get_inode(sb, vino, NULL);
+}
+
 /**
  * ceph_new_inode - allocate a new inode in advance of an expected create
  * @dir: parent directory for new inode
@@ -1523,6 +1569,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 	struct ceph_vino tvino, dvino;
 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb);
 	struct ceph_client *cl = fsc->client;
+	struct inode *parent_dir = NULL;
 	int err = 0;
 
 	doutc(cl, "%p is_dentry %d is_target %d\n", req,
@@ -1536,10 +1583,17 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 	}
 
 	if (rinfo->head->is_dentry) {
-		struct inode *dir = req->r_parent;
-
-		if (dir) {
-			err = ceph_fill_inode(dir, NULL, &rinfo->diri,
+		/*
+		 * r_parent may be stale, in cases when R_PARENT_LOCKED is not set,
+		 * so we need to get the correct inode
+		 */
+		parent_dir = ceph_get_reply_dir(sb, req->r_parent, rinfo);
+		if (unlikely(IS_ERR(parent_dir))) {
+			err = PTR_ERR(parent_dir);
+			goto done;
+		}
+		if (parent_dir) {
+			err = ceph_fill_inode(parent_dir, NULL, &rinfo->diri,
 					      rinfo->dirfrag, session, -1,
 					      &req->r_caps_reservation);
 			if (err < 0)
@@ -1548,14 +1602,14 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 			WARN_ON_ONCE(1);
 		}
 
-		if (dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME &&
+		if (parent_dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME &&
 		    test_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags) &&
 		    !test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
 			bool is_nokey = false;
 			struct qstr dname;
 			struct dentry *dn, *parent;
 			struct fscrypt_str oname = FSTR_INIT(NULL, 0);
-			struct ceph_fname fname = { .dir	= dir,
+			struct ceph_fname fname = { .dir	= parent_dir,
 						    .name	= rinfo->dname,
 						    .ctext	= rinfo->altname,
 						    .name_len	= rinfo->dname_len,
@@ -1564,10 +1618,10 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 			BUG_ON(!rinfo->head->is_target);
 			BUG_ON(req->r_dentry);
 
-			parent = d_find_any_alias(dir);
+			parent = d_find_any_alias(parent_dir);
 			BUG_ON(!parent);
 
-			err = ceph_fname_alloc_buffer(dir, &oname);
+			err = ceph_fname_alloc_buffer(parent_dir, &oname);
 			if (err < 0) {
 				dput(parent);
 				goto done;
@@ -1576,7 +1630,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 			err = ceph_fname_to_usr(&fname, NULL, &oname, &is_nokey);
 			if (err < 0) {
 				dput(parent);
-				ceph_fname_free_buffer(dir, &oname);
+				ceph_fname_free_buffer(parent_dir, &oname);
 				goto done;
 			}
 			dname.name = oname.name;
@@ -1595,7 +1649,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 				      dname.len, dname.name, dn);
 				if (!dn) {
 					dput(parent);
-					ceph_fname_free_buffer(dir, &oname);
+					ceph_fname_free_buffer(parent_dir, &oname);
 					err = -ENOMEM;
 					goto done;
 				}
@@ -1610,12 +1664,12 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 				    ceph_snap(d_inode(dn)) != tvino.snap)) {
 				doutc(cl, " dn %p points to wrong inode %p\n",
 				      dn, d_inode(dn));
-				ceph_dir_clear_ordered(dir);
+				ceph_dir_clear_ordered(parent_dir);
 				d_delete(dn);
 				dput(dn);
 				goto retry_lookup;
 			}
-			ceph_fname_free_buffer(dir, &oname);
+			ceph_fname_free_buffer(parent_dir, &oname);
 
 			req->r_dentry = dn;
 			dput(parent);
@@ -1794,6 +1848,9 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 					    &dvino, ptvino);
 	}
 done:
+	/* Drop extra ref from ceph_get_reply_dir() if it returned a new inode */
+	if (unlikely(!IS_ERR_OR_NULL(parent_dir) && parent_dir != req->r_parent))
+		iput(parent_dir);
 	doutc(cl, "done err=%d\n", err);
 	return err;
 }
@@ -2487,22 +2544,21 @@ int __ceph_setattr(struct mnt_idmap *idmap, struct inode *inode,
 	int truncate_retry = 20; /* The RMW will take around 50ms */
 	struct dentry *dentry;
 	char *path;
-	int pathlen;
-	u64 pathbase;
 	bool do_sync = false;
 
 	dentry = d_find_alias(inode);
 	if (!dentry) {
 		do_sync = true;
 	} else {
-		path = ceph_mdsc_build_path(mdsc, dentry, &pathlen, &pathbase, 0);
+		struct ceph_path_info path_info;
+		path = ceph_mdsc_build_path(mdsc, dentry, &path_info, 0);
 		if (IS_ERR(path)) {
 			do_sync = true;
 			err = 0;
 		} else {
 			err = ceph_mds_check_access(mdsc, path, MAY_WRITE);
 		}
-		ceph_mdsc_free_path(path, pathlen);
+		ceph_mdsc_free_path_info(&path_info);
 		dput(dentry);
 
 		/* For none EACCES cases will let the MDS do the mds auth check */
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 0f497c3..3bc72b4 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2681,8 +2681,7 @@ static u8 *get_fscrypt_altname(const struct ceph_mds_request *req, u32 *plen)
  * ceph_mdsc_build_path - build a path string to a given dentry
  * @mdsc: mds client
  * @dentry: dentry to which path should be built
- * @plen: returned length of string
- * @pbase: returned base inode number
+ * @path_info: output path, length, base ino+snap, and freepath ownership flag
  * @for_wire: is this path going to be sent to the MDS?
  *
  * Build a string that represents the path to the dentry. This is mostly called
@@ -2700,7 +2699,7 @@ static u8 *get_fscrypt_altname(const struct ceph_mds_request *req, u32 *plen)
  *   foo/.snap/bar -> foo//bar
  */
 char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc, struct dentry *dentry,
-			   int *plen, u64 *pbase, int for_wire)
+			   struct ceph_path_info *path_info, int for_wire)
 {
 	struct ceph_client *cl = mdsc->fsc->client;
 	struct dentry *cur;
@@ -2810,16 +2809,28 @@ char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc, struct dentry *dentry,
 		return ERR_PTR(-ENAMETOOLONG);
 	}
 
-	*pbase = base;
-	*plen = PATH_MAX - 1 - pos;
+	/* Initialize the output structure */
+	memset(path_info, 0, sizeof(*path_info));
+
+	path_info->vino.ino = base;
+	path_info->pathlen = PATH_MAX - 1 - pos;
+	path_info->path = path + pos;
+	path_info->freepath = true;
+
+	/* Set snap from dentry if available */
+	if (d_inode(dentry))
+		path_info->vino.snap = ceph_snap(d_inode(dentry));
+	else
+		path_info->vino.snap = CEPH_NOSNAP;
+
 	doutc(cl, "on %p %d built %llx '%.*s'\n", dentry, d_count(dentry),
-	      base, *plen, path + pos);
+	      base, PATH_MAX - 1 - pos, path + pos);
 	return path + pos;
 }
 
 static int build_dentry_path(struct ceph_mds_client *mdsc, struct dentry *dentry,
-			     struct inode *dir, const char **ppath, int *ppathlen,
-			     u64 *pino, bool *pfreepath, bool parent_locked)
+			     struct inode *dir, struct ceph_path_info *path_info,
+			     bool parent_locked)
 {
 	char *path;
 
@@ -2828,41 +2839,47 @@ static int build_dentry_path(struct ceph_mds_client *mdsc, struct dentry *dentry
 		dir = d_inode_rcu(dentry->d_parent);
 	if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP &&
 	    !IS_ENCRYPTED(dir)) {
-		*pino = ceph_ino(dir);
+		path_info->vino.ino = ceph_ino(dir);
+		path_info->vino.snap = ceph_snap(dir);
 		rcu_read_unlock();
-		*ppath = dentry->d_name.name;
-		*ppathlen = dentry->d_name.len;
+		path_info->path = dentry->d_name.name;
+		path_info->pathlen = dentry->d_name.len;
+		path_info->freepath = false;
 		return 0;
 	}
 	rcu_read_unlock();
-	path = ceph_mdsc_build_path(mdsc, dentry, ppathlen, pino, 1);
+	path = ceph_mdsc_build_path(mdsc, dentry, path_info, 1);
 	if (IS_ERR(path))
 		return PTR_ERR(path);
-	*ppath = path;
-	*pfreepath = true;
+	/*
+	 * ceph_mdsc_build_path already fills path_info, including snap handling.
+	 */
 	return 0;
 }
 
-static int build_inode_path(struct inode *inode,
-			    const char **ppath, int *ppathlen, u64 *pino,
-			    bool *pfreepath)
+static int build_inode_path(struct inode *inode, struct ceph_path_info *path_info)
 {
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
 	struct dentry *dentry;
 	char *path;
 
 	if (ceph_snap(inode) == CEPH_NOSNAP) {
-		*pino = ceph_ino(inode);
-		*ppathlen = 0;
+		path_info->vino.ino = ceph_ino(inode);
+		path_info->vino.snap = ceph_snap(inode);
+		path_info->pathlen = 0;
+		path_info->freepath = false;
 		return 0;
 	}
 	dentry = d_find_alias(inode);
-	path = ceph_mdsc_build_path(mdsc, dentry, ppathlen, pino, 1);
+	path = ceph_mdsc_build_path(mdsc, dentry, path_info, 1);
 	dput(dentry);
 	if (IS_ERR(path))
 		return PTR_ERR(path);
-	*ppath = path;
-	*pfreepath = true;
+	/*
+	 * ceph_mdsc_build_path already fills path_info, including snap from dentry.
+	 * Override with inode's snap since that's what this function is for.
+	 */
+	path_info->vino.snap = ceph_snap(inode);
 	return 0;
 }
 
@@ -2872,26 +2889,32 @@ static int build_inode_path(struct inode *inode,
  */
 static int set_request_path_attr(struct ceph_mds_client *mdsc, struct inode *rinode,
 				 struct dentry *rdentry, struct inode *rdiri,
-				 const char *rpath, u64 rino, const char **ppath,
-				 int *pathlen, u64 *ino, bool *freepath,
+				 const char *rpath, u64 rino,
+				 struct ceph_path_info *path_info,
 				 bool parent_locked)
 {
 	struct ceph_client *cl = mdsc->fsc->client;
 	int r = 0;
 
+	/* Initialize the output structure */
+	memset(path_info, 0, sizeof(*path_info));
+
 	if (rinode) {
-		r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
+		r = build_inode_path(rinode, path_info);
 		doutc(cl, " inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
 		      ceph_snap(rinode));
 	} else if (rdentry) {
-		r = build_dentry_path(mdsc, rdentry, rdiri, ppath, pathlen, ino,
-					freepath, parent_locked);
-		doutc(cl, " dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen, *ppath);
+		r = build_dentry_path(mdsc, rdentry, rdiri, path_info, parent_locked);
+		doutc(cl, " dentry %p %llx/%.*s\n", rdentry, path_info->vino.ino,
+		      path_info->pathlen, path_info->path);
 	} else if (rpath || rino) {
-		*ino = rino;
-		*ppath = rpath;
-		*pathlen = rpath ? strlen(rpath) : 0;
-		doutc(cl, " path %.*s\n", *pathlen, rpath);
+		path_info->vino.ino = rino;
+		path_info->vino.snap = CEPH_NOSNAP;
+		path_info->path = rpath;
+		path_info->pathlen = rpath ? strlen(rpath) : 0;
+		path_info->freepath = false;
+
+		doutc(cl, " path %.*s\n", path_info->pathlen, rpath);
 	}
 
 	return r;
@@ -2968,11 +2991,8 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 	struct ceph_client *cl = mdsc->fsc->client;
 	struct ceph_msg *msg;
 	struct ceph_mds_request_head_legacy *lhead;
-	const char *path1 = NULL;
-	const char *path2 = NULL;
-	u64 ino1 = 0, ino2 = 0;
-	int pathlen1 = 0, pathlen2 = 0;
-	bool freepath1 = false, freepath2 = false;
+	struct ceph_path_info path_info1 = {0};
+	struct ceph_path_info path_info2 = {0};
 	struct dentry *old_dentry = NULL;
 	int len;
 	u16 releases;
@@ -2982,25 +3002,49 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 	u16 request_head_version = mds_supported_head_version(session);
 	kuid_t caller_fsuid = req->r_cred->fsuid;
 	kgid_t caller_fsgid = req->r_cred->fsgid;
+	bool parent_locked = test_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 
 	ret = set_request_path_attr(mdsc, req->r_inode, req->r_dentry,
-			      req->r_parent, req->r_path1, req->r_ino1.ino,
-			      &path1, &pathlen1, &ino1, &freepath1,
-			      test_bit(CEPH_MDS_R_PARENT_LOCKED,
-					&req->r_req_flags));
+				    req->r_parent, req->r_path1, req->r_ino1.ino,
+				    &path_info1, parent_locked);
 	if (ret < 0) {
 		msg = ERR_PTR(ret);
 		goto out;
 	}
 
+	/*
+	 * When the parent directory's i_rwsem is *not* locked, req->r_parent may
+	 * have become stale (e.g. after a concurrent rename) between the time the
+	 * dentry was looked up and now.  If we detect that the stored r_parent
+	 * does not match the inode number we just encoded for the request, switch
+	 * to the correct inode so that the MDS receives a valid parent reference.
+	 */
+	if (!parent_locked && req->r_parent && path_info1.vino.ino &&
+	    ceph_ino(req->r_parent) != path_info1.vino.ino) {
+		struct inode *old_parent = req->r_parent;
+		struct inode *correct_dir = ceph_get_inode(mdsc->fsc->sb, path_info1.vino, NULL);
+		if (!IS_ERR(correct_dir)) {
+			WARN_ONCE(1, "ceph: r_parent mismatch (had %llx wanted %llx) - updating\n",
+			          ceph_ino(old_parent), path_info1.vino.ino);
+			/*
+			 * Transfer CEPH_CAP_PIN from the old parent to the new one.
+			 * The pin was taken earlier in ceph_mdsc_submit_request().
+			 */
+			ceph_put_cap_refs(ceph_inode(old_parent), CEPH_CAP_PIN);
+			iput(old_parent);
+			req->r_parent = correct_dir;
+			ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
+		}
+	}
+
 	/* If r_old_dentry is set, then assume that its parent is locked */
 	if (req->r_old_dentry &&
 	    !(req->r_old_dentry->d_flags & DCACHE_DISCONNECTED))
 		old_dentry = req->r_old_dentry;
 	ret = set_request_path_attr(mdsc, NULL, old_dentry,
-			      req->r_old_dentry_dir,
-			      req->r_path2, req->r_ino2.ino,
-			      &path2, &pathlen2, &ino2, &freepath2, true);
+				    req->r_old_dentry_dir,
+				    req->r_path2, req->r_ino2.ino,
+				    &path_info2, true);
 	if (ret < 0) {
 		msg = ERR_PTR(ret);
 		goto out_free1;
@@ -3031,7 +3075,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 
 	/* filepaths */
 	len += 2 * (1 + sizeof(u32) + sizeof(u64));
-	len += pathlen1 + pathlen2;
+	len += path_info1.pathlen + path_info2.pathlen;
 
 	/* cap releases */
 	len += sizeof(struct ceph_mds_request_release) *
@@ -3039,9 +3083,9 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 		 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
 
 	if (req->r_dentry_drop)
-		len += pathlen1;
+		len += path_info1.pathlen;
 	if (req->r_old_dentry_drop)
-		len += pathlen2;
+		len += path_info2.pathlen;
 
 	/* MClientRequest tail */
 
@@ -3154,8 +3198,8 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 	lhead->ino = cpu_to_le64(req->r_deleg_ino);
 	lhead->args = req->r_args;
 
-	ceph_encode_filepath(&p, end, ino1, path1);
-	ceph_encode_filepath(&p, end, ino2, path2);
+	ceph_encode_filepath(&p, end, path_info1.vino.ino, path_info1.path);
+	ceph_encode_filepath(&p, end, path_info2.vino.ino, path_info2.path);
 
 	/* make note of release offset, in case we need to replay */
 	req->r_request_release_offset = p - msg->front.iov_base;
@@ -3218,11 +3262,9 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
 	msg->hdr.data_off = cpu_to_le16(0);
 
 out_free2:
-	if (freepath2)
-		ceph_mdsc_free_path((char *)path2, pathlen2);
+	ceph_mdsc_free_path_info(&path_info2);
 out_free1:
-	if (freepath1)
-		ceph_mdsc_free_path((char *)path1, pathlen1);
+	ceph_mdsc_free_path_info(&path_info1);
 out:
 	return msg;
 out_err:
@@ -4579,24 +4621,20 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 	struct ceph_pagelist *pagelist = recon_state->pagelist;
 	struct dentry *dentry;
 	struct ceph_cap *cap;
-	char *path;
-	int pathlen = 0, err;
-	u64 pathbase;
+	struct ceph_path_info path_info = {0};
+	int err;
 	u64 snap_follows;
 
 	dentry = d_find_primary(inode);
 	if (dentry) {
 		/* set pathbase to parent dir when msg_version >= 2 */
-		path = ceph_mdsc_build_path(mdsc, dentry, &pathlen, &pathbase,
+		char *path = ceph_mdsc_build_path(mdsc, dentry, &path_info,
 					    recon_state->msg_version >= 2);
 		dput(dentry);
 		if (IS_ERR(path)) {
 			err = PTR_ERR(path);
 			goto out_err;
 		}
-	} else {
-		path = NULL;
-		pathbase = 0;
 	}
 
 	spin_lock(&ci->i_ceph_lock);
@@ -4629,7 +4667,7 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 		rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
 		rec.v2.issued = cpu_to_le32(cap->issued);
 		rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
-		rec.v2.pathbase = cpu_to_le64(pathbase);
+		rec.v2.pathbase = cpu_to_le64(path_info.vino.ino);
 		rec.v2.flock_len = (__force __le32)
 			((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
 	} else {
@@ -4644,7 +4682,7 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 		ts = inode_get_atime(inode);
 		ceph_encode_timespec64(&rec.v1.atime, &ts);
 		rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
-		rec.v1.pathbase = cpu_to_le64(pathbase);
+		rec.v1.pathbase = cpu_to_le64(path_info.vino.ino);
 	}
 
 	if (list_empty(&ci->i_cap_snaps)) {
@@ -4706,7 +4744,7 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 			    sizeof(struct ceph_filelock);
 		rec.v2.flock_len = cpu_to_le32(struct_len);
 
-		struct_len += sizeof(u32) + pathlen + sizeof(rec.v2);
+		struct_len += sizeof(u32) + path_info.pathlen + sizeof(rec.v2);
 
 		if (struct_v >= 2)
 			struct_len += sizeof(u64); /* snap_follows */
@@ -4730,7 +4768,7 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 			ceph_pagelist_encode_8(pagelist, 1);
 			ceph_pagelist_encode_32(pagelist, struct_len);
 		}
-		ceph_pagelist_encode_string(pagelist, path, pathlen);
+		ceph_pagelist_encode_string(pagelist, (char *)path_info.path, path_info.pathlen);
 		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
 		ceph_locks_to_pagelist(flocks, pagelist,
 				       num_fcntl_locks, num_flock_locks);
@@ -4741,17 +4779,17 @@ static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
 	} else {
 		err = ceph_pagelist_reserve(pagelist,
 					    sizeof(u64) + sizeof(u32) +
-					    pathlen + sizeof(rec.v1));
+					    path_info.pathlen + sizeof(rec.v1));
 		if (err)
 			goto out_err;
 
 		ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
-		ceph_pagelist_encode_string(pagelist, path, pathlen);
+		ceph_pagelist_encode_string(pagelist, (char *)path_info.path, path_info.pathlen);
 		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
 	}
 
 out_err:
-	ceph_mdsc_free_path(path, pathlen);
+	ceph_mdsc_free_path_info(&path_info);
 	if (!err)
 		recon_state->nr_caps++;
 	return err;
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 3e2a6fa..0428a5e 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -617,14 +617,24 @@ extern int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath,
 
 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 
-static inline void ceph_mdsc_free_path(char *path, int len)
+/*
+ * Structure to group path-related output parameters for build_*_path functions
+ */
+struct ceph_path_info {
+	const char *path;
+	int pathlen;
+	struct ceph_vino vino;
+	bool freepath;
+};
+
+static inline void ceph_mdsc_free_path_info(const struct ceph_path_info *path_info)
 {
-	if (!IS_ERR_OR_NULL(path))
-		__putname(path - (PATH_MAX - 1 - len));
+	if (path_info && path_info->freepath && !IS_ERR_OR_NULL(path_info->path))
+		__putname((char *)path_info->path - (PATH_MAX - 1 - path_info->pathlen));
 }
 
 extern char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc,
-				  struct dentry *dentry, int *plen, u64 *base,
+				  struct dentry *dentry, struct ceph_path_info *path_info,
 				  int for_wire);
 
 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index d1b5705..9f6d860 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1524,7 +1524,7 @@ static void con_fault_finish(struct ceph_connection *con)
 	 * in case we faulted due to authentication, invalidate our
 	 * current tickets so that we can get new ones.
 	 */
-	if (con->v1.auth_retry) {
+	if (!ceph_msgr2(from_msgr(con->msgr)) && con->v1.auth_retry) {
 		dout("auth_retry %d, invalidating\n", con->v1.auth_retry);
 		if (con->ops->invalidate_authorizer)
 			con->ops->invalidate_authorizer(con);
@@ -1714,9 +1714,10 @@ static void clear_standby(struct ceph_connection *con)
 {
 	/* come back from STANDBY? */
 	if (con->state == CEPH_CON_S_STANDBY) {
-		dout("clear_standby %p and ++connect_seq\n", con);
+		dout("clear_standby %p\n", con);
 		con->state = CEPH_CON_S_PREOPEN;
-		con->v1.connect_seq++;
+		if (!ceph_msgr2(from_msgr(con->msgr)))
+			con->v1.connect_seq++;
 		WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING));
 		WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_KEEPALIVE_PENDING));
 	}