From 62dd63761701a7e0f7ce39f4071dcabc19bb1cf4 Mon Sep 17 00:00:00 2001 From: Greg Farnum Date: Thu, 16 Jul 2015 04:45:05 -0700 Subject: [PATCH] Client: check dir is still complete after dropping locks in _readdir_cache_cb We drop the lock when invoking the callback, which means the directory we're looking at might get dentries trimmed out of memory. Make sure that hasn't happened after we get the lock back. If it *has* happened, fall back to requesting the directory contents from the MDS. Update the dirp location pointers after each entry to facilitate this. Because this requires we update the dirp->at_cache_name value on every loop, we rework the updating scheme a bit: to dereference the dn->name before unlocking, so we know it's filled in; and since we update it on every loop we don't need to refer to the previous dentry explicitly like we did before. This should also handle racing file deletes: we get back a trace on the removed dentry and that will clear the COMPLETE|ORDERED flags. Fixes #12297 Signed-off-by: Greg Farnum --- src/client/Client.cc | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/src/client/Client.cc b/src/client/Client.cc index f5c97a128949c..abadc8bf296c8 100644 --- a/src/client/Client.cc +++ b/src/client/Client.cc @@ -6254,8 +6254,12 @@ int Client::_readdir_cache_cb(dir_result_t *dirp, add_dirent_cb_t cb, void *p) ++pd; } - string prev_name; - while (!pd.end()) { + string dn_name; + while (true) { + if (!dirp->inode->is_complete_and_ordered()) + return -EAGAIN; + if (pd.end()) + break; Dentry *dn = *pd; if (dn->inode == NULL) { ldout(cct, 15) << " skipping null '" << dn->name << "'" << dendl; @@ -6278,6 +6282,8 @@ int Client::_readdir_cache_cb(dir_result_t *dirp, add_dirent_cb_t cb, void *p) if (pd.end()) next_off = dir_result_t::END; + dn_name = dn->name; // fill in name while we have lock + client_lock.Unlock(); int r = cb(p, &de, &st, stmask, next_off); // _next_ offset client_lock.Lock(); @@ -6285,13 +6291,12 @@ int Client::_readdir_cache_cb(dir_result_t *dirp, add_dirent_cb_t cb, void *p) << " = " << r << dendl; if (r < 0) { - dirp->next_offset = dn->offset; - dirp->at_cache_name = prev_name; + dirp->next_offset = next_off - 1; return r; } - prev_name = dn->name; - dirp->offset = next_off; + dirp->next_offset = dirp->offset = next_off; + dirp->at_cache_name = dn_name; // we successfully returned this one; update! if (r > 0) return r; } -- 2.39.5