From 78654d270cde028c5d7f9da29b2790b90c19e11f Mon Sep 17 00:00:00 2001 From: Anand Avati Date: Mon, 15 Nov 2010 05:34:00 +0000 Subject: nfs: opendir/closedir for every readdir Revert "nfs3: Unref & unbind dir fd with inode lock on EOF" This reverts commit 4e6fb304ce41acbaf7c9ba67c06bf443e65082e8. The above commit (which unbinds fds at EOF) does not fix the original bug (1619) because a readdir from a second app could have already started before the readdir_cbk of the first app's readdir reaches NFS code. Hence the race still exists. Performing extra unrefs when EOF is received is not a reliable way of detecting that a client has performed a closedir (and to close the fd ourselves). Neither is interpreting a 0 cookies a new opendir. Clients can always use telldir/seekdir and hit EOFs twice. Due to the way NFS3 protocol is designed, it is just not possible for the server to reliably detect opendirs/closedirs performed by the client and map the corresponding readdirs to the same dir fd on the server side. The only reliable way of fixing this is to perform opendir/closedir at the cost of performance. Any optimization towards keeping dir fds open attempting to map them with application's opendir/closedir will either result in fd leaks or extra fd unrefs. Signed-off-by: Anand V. Avati Signed-off-by: Anand V. Avati BUG: 2061 (NFS server crashes in readdir_fstat_cbk due to extra fd unref) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2061 --- xlators/nfs/server/src/nfs3-helpers.c | 2 +- xlators/nfs/server/src/nfs3.c | 17 ++++------------- 2 files changed, 5 insertions(+), 14 deletions(-) (limited to 'xlators/nfs') diff --git a/xlators/nfs/server/src/nfs3-helpers.c b/xlators/nfs/server/src/nfs3-helpers.c index cff029d6..8e4ca372 100644 --- a/xlators/nfs/server/src/nfs3-helpers.c +++ b/xlators/nfs/server/src/nfs3-helpers.c @@ -1775,7 +1775,7 @@ nfs3_dir_open_cbk (call_frame_t *frame, void *cookie, xlator_t *this, goto err; } - cs->fd = fd_ref (fd); + cs->fd = fd; /* Gets unrefd when the call state is wiped. */ nfs3_set_inode_opened (cs->nfsx, cs->resolvedloc.inode); gf_log (GF_NFS3, GF_LOG_TRACE, "FD_REF: %d", fd->refcount); nfs3_call_resume (cs); diff --git a/xlators/nfs/server/src/nfs3.c b/xlators/nfs/server/src/nfs3.c index 7fed84d5..ce592752 100644 --- a/xlators/nfs/server/src/nfs3.c +++ b/xlators/nfs/server/src/nfs3.c @@ -3889,17 +3889,6 @@ nfs3svc_readdir_fstat_cbk (call_frame_t *frame, void *cookie, xlator_t *this, stat = NFS3_OK; nfs3err: - - /* On end-of-directory, unref the fd to have it removed from the cache - * and also unbind it from the fd so that any subsequent request on the - * on the directory do not get this fd when fd_lookup is called in - * dir open resume path. - */ - if (is_eof) { - gf_log (GF_NFS3, GF_LOG_TRACE, "EOF REF: %d", cs->fd->refcount); - fd_unref_unbind (cs->fd); - } - if (cs->maxcount == 0) { nfs3_log_readdir_res (nfs_rpcsvc_request_xid (cs->req), stat, op_errno, (uintptr_t)cs->fd, @@ -3917,7 +3906,10 @@ nfs3err: cs->maxcount, is_eof); } - gf_log (GF_NFS3, GF_LOG_TRACE, "CS WIPE REF: %d", cs->fd->refcount); + if (is_eof) { + /* do nothing */ + } + nfs3_call_state_wipe (cs); return 0; } @@ -3968,7 +3960,6 @@ err: * so that next time the dir is read, we'll get any changed directory * entries. */ - fd_unref_unbind (cs->fd); nfs3_call_state_wipe (cs); ret: return 0; -- cgit