mds: change MDCache::path_traverse()'s 'onfail' argument to flags

Later pathes will introduce more flags

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index e7472abdf812e8bbd7392cb505aa076f322bb462..4dd949584591b7e3442fb09854f23f9801e2f75e 100644 (file)
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -8047,17 +8047,16 @@ void MDCache::dispatch(const cref_t<Message> &m)
   }
 }
 
-int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,     // who
-                           const filepath& path,                   // what
-                           vector<CDentry*> *pdnvec,         // result
-                           CInode **pin,
-                           int onfail)
+int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,
+                           const filepath& path, int flags,
+                           vector<CDentry*> *pdnvec, CInode **pin)
 {
-  bool discover = (onfail == MDS_TRAVERSE_DISCOVER);
-  bool null_okay = (onfail == MDS_TRAVERSE_DISCOVERXLOCK);
-  bool forward = (onfail == MDS_TRAVERSE_FORWARD);
+  bool discover = (flags & MDS_TRAVERSE_DISCOVER);
+  bool forward = !discover;
+  bool last_xlocked = (flags & MDS_TRAVERSE_LAST_XLOCKED);
 
-  ceph_assert(!forward || mdr);  // forward requires a request
+  if (forward)
+    ceph_assert(mdr);  // forward requires a request
 
   snapid_t snapid = CEPH_NOSNAP;
   if (mdr)
@@ -8156,7 +8155,7 @@ int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,     // who
         // discover?
        dout(10) << "traverse: need dirfrag " << fg << ", doing discover from " << *cur << dendl;
        discover_path(cur, snapid, path.postfixpath(depth), cf.build(),
-                     null_okay);
+                     last_xlocked);
        if (mds->logger) mds->logger->inc(l_mds_traverse_discover);
         return 1;
       }
@@ -8193,7 +8192,7 @@ int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,     // who
     CDentry::linkage_t *dnl = dn ? dn->get_projected_linkage() : 0;
 
     // null and last_bit and xlocked by me?
-    if (dnl && dnl->is_null() && null_okay) {
+    if (dnl && dnl->is_null() && last_xlocked) {
       dout(10) << "traverse: hit null dentry at tail of traverse, succeeding" << dendl;
       if (pdnvec)
        pdnvec->push_back(dn);
@@ -8253,7 +8252,7 @@ int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,     // who
             return -EIO;
           }
           open_remote_dentry(dn, true, cf.build(),
-                            (null_okay && depth == path.depth() - 1));
+                            (last_xlocked && depth == path.depth() - 1));
          if (mds->logger) mds->logger->inc(l_mds_traverse_remote_ino);
           return 1;
         }        
@@ -8339,10 +8338,10 @@ int MDCache::path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,     // who
        discover = true;
       }
 
-      if ((discover || null_okay)) {
+      if ((discover)) {
        dout(7) << "traverse: discover from " << path[depth] << " from " << *curdir << dendl;
        discover_path(curdir, snapid, path.postfixpath(depth), cf.build(),
-                     null_okay);
+                     last_xlocked);
        if (mds->logger) mds->logger->inc(l_mds_traverse_discover);
         return 1;
       } 
@@ -9164,7 +9163,7 @@ void MDCache::handle_find_ino_reply(const cref_t<MMDSFindInoReply> &m)
       vector<CDentry*> trace;
       CF_MDS_RetryMessageFactory cf(mds, m);
       MDRequestRef null_ref;
-      int r = path_traverse(null_ref, cf, m->path, &trace, NULL, MDS_TRAVERSE_DISCOVER);
+      int r = path_traverse(null_ref, cf, m->path, MDS_TRAVERSE_DISCOVER, &trace);
       if (r > 0)
        return; 
       dout(0) << "handle_find_ino_reply failed with " << r << " on " << m->path 
@@ -10721,7 +10720,7 @@ void MDCache::handle_dir_update(const cref_t<MDirUpdate> &m)
       dout(5) << "trying discover on dir_update for " << path << dendl;
       CF_MDS_RetryMessageFactory cf(mds, m);
       MDRequestRef null_ref;
-      int r = path_traverse(null_ref, cf, path, &trace, &in, MDS_TRAVERSE_DISCOVER);
+      int r = path_traverse(null_ref, cf, path, MDS_TRAVERSE_DISCOVER, &trace, &in);
       if (r > 0)
         return;
       if (r == 0 &&

diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index abed6a6d26e3c01ef1dd83b44e06efe85b790554..d416d0fb9cf53e3a91b8a124eef284c9199f0146 100644 (file)
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -110,6 +110,9 @@ enum {
   l_mdc_last,
 };
 
+// flags for path_traverse();
+static const int MDS_TRAVERSE_DISCOVER         = (1 << 0);
+static const int MDS_TRAVERSE_LAST_XLOCKED     = (1 << 1);
 
 // flags for predirty_journal_parents()
 static const int PREDIRTY_PRIMARY = 1; // primary dn, adjust nested accounting
@@ -759,19 +762,21 @@ class MDCache {
    * @param mdr The MDRequest associated with the path. Can be null.
    * @param cf A MDSContextFactory for waiter building.
    * @param path The path to traverse to.
+   *
+   * @param flags Specifies different lookup behaviors.
+   * By default, path_traverse() forwards the request to the auth MDS if that
+   * is appropriate (ie, if it doesn't know the contents of a directory).
+   * MDS_TRAVERSE_DISCOVER: Instead of forwarding request, path_traverse()
+   * attempts to look up the path from a different MDS (and bring them into
+   * its cache as replicas).
+   * MDS_TRAVERSE_LAST_XLOCKED: path_traverse() will succeed on xlocked tail
+   * dentry (return 0 even it's null).
+   *
    * @param pdnvec Data return parameter -- on success, contains a
    * vector of dentries. On failure, is either empty or contains the
    * full trace of traversable dentries.
    * @param pin Data return parameter -- if successful, points to the inode
    * associated with filepath. If unsuccessful, is null.
-   * @param onfail Specifies different lookup failure behaviors. If set to
-   * MDS_TRAVERSE_DISCOVERXLOCK, path_traverse will succeed on null
-   * dentries (instead of returning -ENOENT). If set to
-   * MDS_TRAVERSE_FORWARD, it will forward the request to the auth
-   * MDS if that becomes appropriate (ie, if it doesn't know the contents
-   * of a directory). If set to MDS_TRAVERSE_DISCOVER, it
-   * will attempt to look up the path from a different MDS (and bring them
-   * into its cache as replicas).
    *
    * @returns 0 on success, 1 on "not done yet", 2 on "forwarding", -errno otherwise.
    * If it returns 1, the requester associated with this call has been placed
@@ -779,8 +784,9 @@ class MDCache {
    * If it returns 2 the request has been forwarded, and again the requester
    * should unwind itself and back out.
    */
-  int path_traverse(MDRequestRef& mdr, MDSContextFactory& cf, const filepath& path,
-                   vector<CDentry*> *pdnvec, CInode **pin, int onfail);
+  int path_traverse(MDRequestRef& mdr, MDSContextFactory& cf,
+                   const filepath& path, int flags,
+                   vector<CDentry*> *pdnvec, CInode **pin=nullptr);
 
   CInode *cache_traverse(const filepath& path);
 

diff --git a/src/mds/Migrator.cc b/src/mds/Migrator.cc
index a9b6b80b7f0c1a03a279c3a2f8ea789ea9727e06..d717f3b1ddf5f32fcb398c9ce3640f9728f9e66a 100644 (file)
--- a/src/mds/Migrator.cc
+++ b/src/mds/Migrator.cc
@@ -2302,7 +2302,7 @@ void Migrator::handle_export_discover(const cref_t<MExportDirDiscover> &m, bool
     filepath fpath(m->get_path());
     vector<CDentry*> trace;
     MDRequestRef null_ref;
-    int r = cache->path_traverse(null_ref, cf, fpath, &trace, NULL, MDS_TRAVERSE_DISCOVER);
+    int r = cache->path_traverse(null_ref, cf, fpath, MDS_TRAVERSE_DISCOVER, &trace);
     if (r > 0) return;
     if (r < 0) {
       dout(7) << "handle_export_discover failed to discover or not dir " << m->get_path() << ", NAK" << dendl;

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 2e50ccbdb7dadd4a2d32b9f826ea302b55f4dca7..ae83a48d53cbd46a1ef825be7bf52bd9a9c5512b 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -3390,7 +3390,7 @@ CDir *Server::traverse_to_auth_dir(MDRequestRef& mdr, vector<CDentry*> &trace, f
   // traverse to parent dir
   CInode *diri;
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, refpath, &trace, &diri, MDS_TRAVERSE_FORWARD);
+  int r = mdcache->path_traverse(mdr, cf, refpath, 0, &trace, &diri);
   if (r > 0) return 0; // delayed
   if (r < 0) {
     if (r == -ESTALE) {
@@ -3429,7 +3429,7 @@ CInode* Server::rdlock_path_pin_ref(MDRequestRef& mdr, int n,
 
   // traverse
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, refpath, &mdr->dn[n], &mdr->in[n], MDS_TRAVERSE_FORWARD);
+  int r = mdcache->path_traverse(mdr, cf, refpath, 0, &mdr->dn[n], &mdr->in[n]);
   if (r > 0)
     return NULL; // delayed
   if (r < 0) {  // error
@@ -4199,8 +4199,7 @@ void Server::handle_client_openc(MDRequestRef& mdr)
 
   if (!excl) {
     CF_MDS_MDRContextFactory cf(mdcache, mdr);
-    int r = mdcache->path_traverse(mdr, cf, req->get_filepath(),
-                                  &mdr->dn[0], NULL, MDS_TRAVERSE_FORWARD);
+    int r = mdcache->path_traverse(mdr, cf, req->get_filepath(), 0, &mdr->dn[0]);
     if (r > 0) return;
     if (r == 0) {
       // it existed.
@@ -6749,7 +6748,7 @@ void Server::handle_client_unlink(MDRequestRef& mdr)
   vector<CDentry*> trace;
   CInode *in;
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, refpath, &trace, &in, MDS_TRAVERSE_FORWARD);
+  int r = mdcache->path_traverse(mdr, cf, refpath, 0, &trace, &in);
   if (r > 0) return;
   if (r < 0) {
     if (r == -ESTALE) {
@@ -7137,7 +7136,9 @@ void Server::handle_slave_rmdir_prep(MDRequestRef& mdr)
   dout(10) << " src " << srcpath << dendl;
   CInode *in;
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, srcpath, &trace, &in, MDS_TRAVERSE_DISCOVERXLOCK);
+  int r = mdcache->path_traverse(mdr, cf, srcpath,
+                                MDS_TRAVERSE_DISCOVER | MDS_TRAVERSE_LAST_XLOCKED,
+                                &trace, &in);
   if (r > 0) return;
   if (r == -ESTALE) {
     mdcache->find_ino_peers(srcpath.get_ino(), new C_MDS_RetryRequest(mdcache, mdr),
@@ -7533,7 +7534,7 @@ void Server::handle_client_rename(MDRequestRef& mdr)
   ceph_assert(destdir->is_auth());
 
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, srcpath, &srctrace, NULL, MDS_TRAVERSE_DISCOVER);
+  int r = mdcache->path_traverse(mdr, cf, srcpath, MDS_TRAVERSE_DISCOVER, &srctrace);
   if (r > 0)
     return; // delayed
   if (r < 0) {
@@ -8691,7 +8692,9 @@ void Server::handle_slave_rename_prep(MDRequestRef& mdr)
   dout(10) << " dest " << destpath << dendl;
   vector<CDentry*> trace;
   CF_MDS_MDRContextFactory cf(mdcache, mdr);
-  int r = mdcache->path_traverse(mdr, cf, destpath, &trace, NULL, MDS_TRAVERSE_DISCOVERXLOCK);
+  int r = mdcache->path_traverse(mdr, cf, destpath,
+                                MDS_TRAVERSE_DISCOVER | MDS_TRAVERSE_LAST_XLOCKED,
+                                &trace);
   if (r > 0) return;
   if (r == -ESTALE) {
     mdcache->find_ino_peers(destpath.get_ino(), new C_MDS_RetryRequest(mdcache, mdr),
@@ -8709,7 +8712,9 @@ void Server::handle_slave_rename_prep(MDRequestRef& mdr)
   filepath srcpath(mdr->slave_request->srcdnpath);
   dout(10) << " src " << srcpath << dendl;
   CInode *srci = nullptr;
-  r = mdcache->path_traverse(mdr, cf, srcpath, &trace, &srci, MDS_TRAVERSE_DISCOVERXLOCK);
+  r = mdcache->path_traverse(mdr, cf, srcpath,
+                            MDS_TRAVERSE_DISCOVER | MDS_TRAVERSE_LAST_XLOCKED,
+                            &trace, &srci);
   if (r > 0) return;
   ceph_assert(r == 0);
 

diff --git a/src/mds/mdstypes.h b/src/mds/mdstypes.h
index 2485b28a27b9c4926a222d05254e0ec6bf59097b..be5da40dc9c3c0d3cf7d13c73025a842e5254526 100644 (file)
--- a/src/mds/mdstypes.h
+++ b/src/mds/mdstypes.h
@@ -69,11 +69,6 @@
 #define MDS_INO_STRAY_OWNER(i) (signed (((unsigned (i)) - MDS_INO_STRAY_OFFSET) / NUM_STRAY))
 #define MDS_INO_STRAY_INDEX(i) (((unsigned (i)) - MDS_INO_STRAY_OFFSET) % NUM_STRAY)
 
-#define MDS_TRAVERSE_FORWARD       1
-#define MDS_TRAVERSE_DISCOVER      2    // skips permissions checks etc.
-#define MDS_TRAVERSE_DISCOVERXLOCK 3    // succeeds on (foreign?) null, xlocked dentries.
-
-
 typedef int32_t mds_rank_t;
 constexpr mds_rank_t MDS_RANK_NONE = -1;