[PATCH 6.1.y 1/3] ceph: remove unnecessary check for NULL in parse_longname()

[Sasha Levin <sashal@kernel.org>]

From: Luís Henriques <lhenriques@suse.de>

[ Upstream commit 2816a09678f50fc6a69e742e90cb1fd7a9f1f9ff ]

Function ceph_get_inode() never returns NULL; instead it returns an
ERR_PTR() if something fails.  Thus, the check for NULL in parse_longname()
is useless and can be dropped.  Instead, move there the debug code that
does the error checking so that it's only executed if ceph_get_inode() is
called.

Fixes: dd66df0053ef ("ceph: add support for encrypted snapshot names")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Stable-dependency adaptation: fs/ceph/crypto.c is not present in 6.1, so
drop the original hunk.  Instead, carry the minimal existing-code context
needed by the follow-up: use client-aware logging in the delegated-inode
parser, serialize the delegated-inode xarray teardown, and reject reconnects
for terminal sessions.  This gives the follow-up's counter reset a clean and
correct insertion point.

[ sashal: Reduced backport -- upstream 2816a09678f50 touches 1 file(s), this
  backport carries 1. Not backported here:
  fs/ceph/crypto.c
  This note is generated from the file lists only; see the resolution record
  for the reasoning. ]

Stable-dep-of: 4bd3158bd624 ("ceph: cap delegated inode count in ceph_parse_deleg_inos()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ceph/mds_client.c | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 939f9e870de0a..4893545b930c3 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -433,6 +433,7 @@ static int parse_reply_info_filelock(void **p, void *end,
 static int ceph_parse_deleg_inos(void **p, void *end,
 				 struct ceph_mds_session *s)
 {
+	struct ceph_client *cl = s->s_mdsc->fsc->client;
 	u32 sets;
 
 	ceph_decode_32_safe(p, end, sets, bad);
@@ -445,8 +446,9 @@ static int ceph_parse_deleg_inos(void **p, void *end,
 
 		/* Don't accept a delegation of system inodes */
 		if (start < CEPH_INO_SYSTEM_BASE) {
-			pr_warn_ratelimited("ceph: ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n",
-					start, len);
+			pr_warn_ratelimited_client(cl,
+				"ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n",
+				start, len);
 			continue;
 		}
 		while (len--) {
@@ -454,10 +456,10 @@ static int ceph_parse_deleg_inos(void **p, void *end,
 					    DELEGATED_INO_AVAILABLE,
 					    GFP_KERNEL);
 			if (!err) {
-				dout("added delegated inode 0x%llx\n",
-				     start - 1);
+				doutc(cl, "added delegated inode 0x%llx\n", start - 1);
 			} else if (err == -EBUSY) {
-				pr_warn("MDS delegated inode 0x%llx more than once.\n",
+				pr_warn_client(cl,
+					"MDS delegated inode 0x%llx more than once.\n",
 					start - 1);
 			} else {
 				return err;
@@ -4200,6 +4202,7 @@ static int encode_snap_realms(struct ceph_mds_client *mdsc,
 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
 			       struct ceph_mds_session *session)
 {
+	struct ceph_client *cl = mdsc->fsc->client;
 	struct ceph_msg *reply;
 	int mds = session->s_mds;
 	int err = -ENOMEM;
@@ -4218,9 +4221,21 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
 	if (!reply)
 		goto fail_nomsg;
 
+	mutex_lock(&session->s_mutex);
+
+	/* Serialized by s_mutex against concurrent ceph_get_deleg_ino(). */
 	xa_destroy(&session->s_delegated_inos);
+	if (session->s_state == CEPH_MDS_SESSION_CLOSED ||
+	    session->s_state == CEPH_MDS_SESSION_REJECTED) {
+		pr_info_client(cl, "mds%d skipping reconnect, session %s\n",
+			       mds,
+			       ceph_session_state_name(session->s_state));
+		mutex_unlock(&session->s_mutex);
+		ceph_msg_put(reply);
+		err = -ESTALE;
+		goto fail_return;
+	}
 
-	mutex_lock(&session->s_mutex);
 	session->s_state = CEPH_MDS_SESSION_RECONNECTING;
 	session->s_seq = 0;
 
@@ -4361,6 +4376,10 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
 fail_nopagelist:
 	pr_err("error %d preparing reconnect for mds%d\n", err, mds);
 	return;
+
+fail_return:
+	ceph_pagelist_release(recon_state.pagelist);
+	return;
 }
 
 
-- 
2.53.0