ceph: flush dirty caps via the cap_dirty list

Previously we were flushing dirty caps by passing an extra flag
when traversing the delayed caps list.  Besides being a bit ugly,
that can also miss caps that are dirty but didn't result in a
cap requeue: notably, mark_caps_dirty().

Separate the flushing into a separate helper, and traverse the
cap_dirty list.

This also brings i_dirty_item in line with i_dirty_caps: we are
on the list IFF caps != 0.  We carry an inode ref IFF
dirty_caps|flushing_caps != 0.

Lose the unused return value from __ceph_mark_caps_dirty().

Signed-off-by: Sage Weil <sage@newdream.net>

3 files changed, 59 insertions, 29 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 111439d883d2..40b8d3471244 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -997,7 +997,7 @@ void ceph_queue_caps_release(struct inode *inode)
                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
                         dout(" release msg %p full\n", msg);
                         list_move_tail(&msg->list_head,
-                                      &session->s_cap_releases_done);
+                                       &session->s_cap_releases_done);
                 } else {
                         dout(" release msg %p at %d/%d (%d)\n", msg,
                              (int)le32_to_cpu(head->num),
@@ -1292,14 +1292,20 @@ static int __mark_caps_flushing(struct inode *inode,
              ceph_cap_string(ci->i_flushing_caps | flushing));
         ci->i_flushing_caps |= flushing;
         ci->i_dirty_caps = 0;
+        dout(" inode %p now !dirty\n", inode);
 
         spin_lock(&mdsc->cap_dirty_lock);
+        list_del_init(&ci->i_dirty_item);
+
+        ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
         if (list_empty(&ci->i_flushing_item)) {
-                list_del_init(&ci->i_dirty_item);
                 list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
                 mdsc->num_cap_flushing++;
-                ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
-                dout(" inode %p now flushing seq %lld\n", &ci->vfs_inode,
+                dout(" inode %p now flushing seq %lld\n", inode,
+                     ci->i_cap_flush_seq);
+        } else {
+                list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
+                dout(" inode %p now flushing (more) seq %lld\n", inode,
                      ci->i_cap_flush_seq);
         }
         spin_unlock(&mdsc->cap_dirty_lock);
@@ -1555,32 +1561,33 @@ ack:
  * Mark caps dirty.  If inode is newly dirty, add to the global dirty
  * list.
  */
-int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
+void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
 {
         struct ceph_mds_client *mdsc = &ceph_client(ci->vfs_inode.i_sb)->mdsc;
         struct inode *inode = &ci->vfs_inode;
-        int was = __ceph_caps_dirty(ci);
+        int was_dirty = ci->i_dirty_caps;
         int dirty = 0;
 
         dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
              ceph_cap_string(mask), ceph_cap_string(ci->i_dirty_caps),
              ceph_cap_string(ci->i_dirty_caps | mask));
         ci->i_dirty_caps |= mask;
-        if (!was) {
+        if (!was_dirty) {
                 dout(" inode %p now dirty\n", &ci->vfs_inode);
                 spin_lock(&mdsc->cap_dirty_lock);
                 list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
                 spin_unlock(&mdsc->cap_dirty_lock);
-                igrab(inode);
-                dirty |= I_DIRTY_SYNC;
+                if (ci->i_flushing_caps == 0) {
+                        igrab(inode);
+                        dirty |= I_DIRTY_SYNC;
+                }
         }
-        if ((was & CEPH_CAP_FILE_BUFFER) &&
+        if (((was_dirty | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
             (mask & CEPH_CAP_FILE_BUFFER))
                 dirty |= I_DIRTY_DATASYNC;
         if (dirty)
                 __mark_inode_dirty(inode, dirty);
         __cap_delay_requeue(mdsc, ci);
-        return was;
 }
 
 /*
@@ -2327,7 +2334,7 @@ static void handle_cap_flush_ack(struct inode *inode,
         int dirty = le32_to_cpu(m->dirty);
         int cleaned = 0;
         u64 flush_tid = le64_to_cpu(m->client_tid);
-        int old_dirty = 0, new_dirty = 0;
+        int drop = 0;
         int i;
 
         for (i = 0; i < CEPH_CAP_BITS; i++)
@@ -2344,9 +2351,7 @@ static void handle_cap_flush_ack(struct inode *inode,
         if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
                 goto out;
 
-        old_dirty = ci->i_dirty_caps | ci->i_flushing_caps;
         ci->i_flushing_caps &= ~cleaned;
-        new_dirty = ci->i_dirty_caps | ci->i_flushing_caps;
 
         spin_lock(&mdsc->cap_dirty_lock);
         if (ci->i_flushing_caps == 0) {
@@ -2360,17 +2365,19 @@ static void handle_cap_flush_ack(struct inode *inode,
                 mdsc->num_cap_flushing--;
                 wake_up(&mdsc->cap_flushing_wq);
                 dout(" inode %p now !flushing\n", inode);
-        }
-        if (old_dirty && !new_dirty) {
-                dout(" inode %p now clean\n", inode);
-                list_del_init(&ci->i_dirty_item);
+
+                if (ci->i_dirty_caps == 0) {
+                        dout(" inode %p now clean\n", inode);
+                        BUG_ON(!list_empty(&ci->i_dirty_item));
+                        drop = 1;
+                }
         }
         spin_unlock(&mdsc->cap_dirty_lock);
         wake_up(&ci->i_cap_wq);
 
 out:
         spin_unlock(&inode->i_lock);
-        if (old_dirty && !new_dirty)
+        if (drop)
                 iput(inode);
 }
 
@@ -2676,14 +2683,11 @@ bad:
 /*
  * Delayed work handler to process end of delayed cap release LRU list.
  */
-void ceph_check_delayed_caps(struct ceph_mds_client *mdsc, int flushdirty)
+void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
 {
         struct ceph_inode_info *ci;
         int flags = CHECK_CAPS_NODELAY;
 
-        if (flushdirty)
-                flags |= CHECK_CAPS_FLUSH;
-
         dout("check_delayed_caps\n");
         while (1) {
                 spin_lock(&mdsc->cap_delay_lock);
@@ -2704,6 +2708,32 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc, int flushdirty)
 }
 
 /*
+ * Flush all dirty caps to the mds
+ */
+void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
+{
+        struct ceph_inode_info *ci;
+        struct inode *inode;
+
+        dout("flush_dirty_caps\n");
+        spin_lock(&mdsc->cap_dirty_lock);
+        while (!list_empty(&mdsc->cap_dirty)) {
+                ci = list_first_entry(&mdsc->cap_dirty,
+                                      struct ceph_inode_info,
+                                      i_dirty_item);
+                inode = igrab(&ci->vfs_inode);
+                spin_unlock(&mdsc->cap_dirty_lock);
+                if (inode) {
+                        ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH,
+                                        NULL);
+                        iput(inode);
+                }
+                spin_lock(&mdsc->cap_dirty_lock);
+        }
+        spin_unlock(&mdsc->cap_dirty_lock);
+}
+
+/*
  * Drop open file reference.  If we were the last open file,
  * we may need to release capabilities to the MDS (or schedule
  * their delayed release).
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 2b19da31a8b3..12d66c0572ac 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2504,7 +2504,7 @@ static void delayed_work(struct work_struct *work)
         int renew_caps;
 
         dout("mdsc delayed_work\n");
-        ceph_check_delayed_caps(mdsc, 0);
+        ceph_check_delayed_caps(mdsc);
 
         mutex_lock(&mdsc->mutex);
         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
@@ -2627,7 +2627,7 @@ void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
         mdsc->stopping = 1;
 
         drop_leases(mdsc);
-        ceph_check_delayed_caps(mdsc, 1);
+        ceph_flush_dirty_caps(mdsc);
         wait_requests(mdsc);
 }
 
@@ -2677,7 +2677,7 @@ void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
         mutex_unlock(&mdsc->mutex);
         dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
 
-        ceph_check_delayed_caps(mdsc, 1);
+        ceph_flush_dirty_caps(mdsc);
 
         wait_unsafe_requests(mdsc, want_tid);
         wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index cfd39ef4023e..0bbf58ab607e 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -524,7 +524,7 @@ static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
 {
         return ci->i_dirty_caps | ci->i_flushing_caps;
 }
-extern int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
+extern void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
 
 extern int ceph_caps_revoking(struct ceph_inode_info *ci, int mask);
 extern int __ceph_caps_used(struct ceph_inode_info *ci);
@@ -814,8 +814,8 @@ extern void __ceph_flush_snaps(struct ceph_inode_info *ci,
                                struct ceph_mds_session **psession);
 extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
                             struct ceph_mds_session *session);
-extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc,
-                                    int flushdirty);
+extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
+extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
 
 extern int ceph_encode_inode_release(void **p, struct inode *inode,
                                      int mds, int drop, int unless, int force);