diff options
author | jhb <jhb@FreeBSD.org> | 2009-06-01 21:17:03 +0000 |
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committer | jhb <jhb@FreeBSD.org> | 2009-06-01 21:17:03 +0000 |
commit | a1af9ecca44f362b24fe3a8342ca6ed8676a399c (patch) | |
tree | 13628b6be10af95db7dc7d8ef88b3291d48583ab /sys/nfsserver | |
parent | 9956d85f164d16d3c1db67cc01f521c1c09d5fdb (diff) | |
download | FreeBSD-src-a1af9ecca44f362b24fe3a8342ca6ed8676a399c.zip FreeBSD-src-a1af9ecca44f362b24fe3a8342ca6ed8676a399c.tar.gz |
Rework socket upcalls to close some races with setup/teardown of upcalls.
- Each socket upcall is now invoked with the appropriate socket buffer
locked. It is not permissible to call soisconnected() with this lock
held; however, so socket upcalls now return an integer value. The two
possible values are SU_OK and SU_ISCONNECTED. If an upcall returns
SU_ISCONNECTED, then the soisconnected() will be invoked on the
socket after the socket buffer lock is dropped.
- A new API is provided for setting and clearing socket upcalls. The
API consists of soupcall_set() and soupcall_clear().
- To simplify locking, each socket buffer now has a separate upcall.
- When a socket upcall returns SU_ISCONNECTED, the upcall is cleared from
the receive socket buffer automatically. Note that a SO_SND upcall
should never return SU_ISCONNECTED.
- All this means that accept filters should now return SU_ISCONNECTED
instead of calling soisconnected() directly. They also no longer need
to explicitly clear the upcall on the new socket.
- The HTTP accept filter still uses soupcall_set() to manage its internal
state machine, but other accept filters no longer have any explicit
knowlege of socket upcall internals aside from their return value.
- The various RPC client upcalls currently drop the socket buffer lock
while invoking soreceive() as a temporary band-aid. The plan for
the future is to add a new flag to allow soreceive() to be called with
the socket buffer locked.
- The AIO callback for socket I/O is now also invoked with the socket
buffer locked. Previously sowakeup() would drop the socket buffer
lock only to call aio_swake() which immediately re-acquired the socket
buffer lock for the duration of the function call.
Discussed with: rwatson, rmacklem
Diffstat (limited to 'sys/nfsserver')
-rw-r--r-- | sys/nfsserver/nfs.h | 2 | ||||
-rw-r--r-- | sys/nfsserver/nfs_srvsock.c | 4 | ||||
-rw-r--r-- | sys/nfsserver/nfs_syscalls.c | 10 |
3 files changed, 7 insertions, 9 deletions
diff --git a/sys/nfsserver/nfs.h b/sys/nfsserver/nfs.h index b47ffea..25fe8ae 100644 --- a/sys/nfsserver/nfs.h +++ b/sys/nfsserver/nfs.h @@ -367,7 +367,7 @@ void nfsrv_timer(void *); int nfsrv_getcache(struct nfsrv_descript *, struct mbuf **); void nfsrv_updatecache(struct nfsrv_descript *, int, struct mbuf *); void nfsrv_cleancache(void); -void nfsrv_rcv(struct socket *so, void *arg, int waitflag); +int nfsrv_rcv(struct socket *so, void *arg, int waitflag); void nfsrv_slpderef(struct nfssvc_sock *slp); void nfsrv_wakenfsd(struct nfssvc_sock *slp); int nfsrv_writegather(struct nfsrv_descript **, struct nfssvc_sock *, diff --git a/sys/nfsserver/nfs_srvsock.c b/sys/nfsserver/nfs_srvsock.c index 639772b..db48869 100644 --- a/sys/nfsserver/nfs_srvsock.c +++ b/sys/nfsserver/nfs_srvsock.c @@ -406,7 +406,7 @@ nfsmout: * Essentially do as much as possible non-blocking, else punt and it will * be called with M_WAIT from an nfsd. */ -void +int nfsrv_rcv(struct socket *so, void *arg, int waitflag) { struct nfssvc_sock *slp = (struct nfssvc_sock *)arg; @@ -420,7 +420,7 @@ nfsrv_rcv(struct socket *so, void *arg, int waitflag) /* XXXRW: Unlocked read. */ if ((slp->ns_flag & SLP_VALID) == 0) - return; + return (SU_OK); /* * We can't do this in the context of a socket callback diff --git a/sys/nfsserver/nfs_syscalls.c b/sys/nfsserver/nfs_syscalls.c index 59a30a3..29c9643 100644 --- a/sys/nfsserver/nfs_syscalls.c +++ b/sys/nfsserver/nfs_syscalls.c @@ -263,11 +263,11 @@ nfssvc_addsock(struct file *fp, struct sockaddr *mynam) slp->ns_nam = mynam; fhold(fp); slp->ns_fp = fp; + NFSD_UNLOCK(); SOCKBUF_LOCK(&so->so_rcv); - so->so_upcallarg = (caddr_t)slp; - so->so_upcall = nfsrv_rcv; - so->so_rcv.sb_flags |= SB_UPCALL; + soupcall_set(so, SO_RCV, nfsrv_rcv, slp); SOCKBUF_UNLOCK(&so->so_rcv); + NFSD_LOCK(); slp->ns_flag = (SLP_VALID | SLP_NEEDQ); nfsrv_wakenfsd(slp); NFSD_UNLOCK(); @@ -585,9 +585,7 @@ nfsrv_zapsock(struct nfssvc_sock *slp) slp->ns_fp = NULL; so = slp->ns_so; SOCKBUF_LOCK(&so->so_rcv); - so->so_rcv.sb_flags &= ~SB_UPCALL; - so->so_upcall = NULL; - so->so_upcallarg = NULL; + soupcall_clear(so, SO_RCV); SOCKBUF_UNLOCK(&so->so_rcv); soshutdown(so, SHUT_RDWR); closef(fp, NULL); |