From 685f9a5d14194fc35db73e5e7370740ccc14b64a Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Mon, 9 Nov 2009 12:05:48 -0800
Subject: [PATCH] ceph: do not confuse stale and dead (unreconnected) caps
We were using the cap_gen to track both stale caps (caps that timed out
due to temporarily losing touch with the mds) and dead caps that did not
reconnect after an MDS failure. Introduce a recon_gen counter to track
reconnections to restarted MDSs and kill dead caps based on that instead.
Rename gen to cap_gen while we're at it to make it more clear which is
which.
Signed-off-by: Sage Weil <sage@newdream.net>
---
fs/ceph/caps.c | 20 +++++++++++++++-----
fs/ceph/mds_client.c | 9 ++++++---
fs/ceph/mds_client.h | 2 ++
fs/ceph/super.h | 4 +++-
4 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 8b863dbec70c..775e6f6fc970 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -609,7 +609,8 @@ int ceph_add_cap(struct inode *inode,
cap->seq = seq;
cap->issue_seq = seq;
cap->mseq = mseq;
- cap->gen = session->s_cap_gen;
+ cap->cap_gen = session->s_cap_gen;
+ cap->recon_gen = session->s_recon_gen;
if (fmode >= 0)
__ceph_get_fmode(ci, fmode);
@@ -626,17 +627,25 @@ int ceph_add_cap(struct inode *inode,
static int __cap_is_valid(struct ceph_cap *cap)
{
unsigned long ttl;
- u32 gen;
+ u32 gen, recon_gen;
spin_lock(&cap->session->s_cap_lock);
gen = cap->session->s_cap_gen;
+ recon_gen = cap->session->s_recon_gen;
ttl = cap->session->s_cap_ttl;
spin_unlock(&cap->session->s_cap_lock);
- if (cap->gen < gen || time_after_eq(jiffies, ttl)) {
+ if (cap->recon_gen != recon_gen) {
+ dout("__cap_is_valid %p cap %p issued %s "
+ "but DEAD (recon_gen %u vs %u)\n", &cap->ci->vfs_inode,
+ cap, ceph_cap_string(cap->issued), cap->recon_gen,
+ recon_gen);
+ return 0;
+ }
+ if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
dout("__cap_is_valid %p cap %p issued %s "
"but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
- cap, ceph_cap_string(cap->issued), cap->gen, gen);
+ cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
return 0;
}
@@ -2203,7 +2212,8 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
issued = __ceph_caps_issued(ci, &implemented);
issued |= implemented | __ceph_caps_dirty(ci);
- cap->gen = session->s_cap_gen;
+ cap->cap_gen = session->s_cap_gen;
+ cap->recon_gen = session->s_recon_gen;
__check_cap_issue(ci, cap, newcaps);
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 210cb6623ea2..828417ae16f9 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -329,6 +329,7 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
ceph_con_open(&s->s_con, ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
spin_lock_init(&s->s_cap_lock);
+ s->s_recon_gen = 0;
s->s_cap_gen = 0;
s->s_cap_ttl = 0;
s->s_renew_requested = 0;
@@ -738,10 +739,11 @@ static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
struct ceph_mds_session *session = arg;
spin_lock(&inode->i_lock);
- if (cap->gen != session->s_cap_gen) {
+ if (cap->recon_gen != session->s_recon_gen) {
pr_err("failed reconnect %p %llx.%llx cap %p "
- "(gen %d < session %d)\n", inode, ceph_vinop(inode),
- cap, cap->gen, session->s_cap_gen);
+ "(recon_gen %d < session %d)\n", inode,
+ ceph_vinop(inode), cap,
+ cap->recon_gen, session->s_recon_gen);
__ceph_remove_cap(cap, NULL);
}
wake_up(&ceph_inode(inode)->i_cap_wq);
@@ -2050,6 +2052,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
session->s_state = CEPH_MDS_SESSION_RECONNECTING;
session->s_seq = 0;
+ session->s_recon_gen++;
ceph_con_open(&session->s_con,
ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index f566e9c84295..c0846b1c482b 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -98,6 +98,8 @@ struct ceph_mds_session {
u64 s_seq; /* incoming msg seq # */
struct mutex s_mutex; /* serialize session messages */
+ int s_recon_gen; /* inc on reconnect to recovered mds */
+
struct ceph_connection s_con;
/* protected by s_cap_lock */
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 05947b96c524..25793559a2e5 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -169,7 +169,9 @@ struct ceph_cap {
int issued; /* latest, from the mds */
int implemented; /* implemented superset of issued (for revocation) */
int mds_wanted;
- u32 seq, issue_seq, mseq, gen;
+ u32 seq, issue_seq, mseq;
+ u32 cap_gen; /* active/stale cycle */
+ u32 recon_gen; /* mds restart reconnect cycle */
unsigned long last_used;
struct list_head caps_item;
};
--
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