renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-15 00:34:10 +08:00
Code

NFS/SUNRPC: Remove other deadlock-avoidance mechanisms in nfs_release_page()

Browse Source 
Now that nfs_release_page() doesn't block indefinitely, other deadlock
avoidance mechanisms aren't needed.
 - it doesn't hurt for kswapd to block occasionally.  If it doesn't
   want to block it would clear __GFP_WAIT.  The current_is_kswapd()
   was only added to avoid deadlocks and we have a new approach for
   that.
 - memory allocation in the SUNRPC layer can very rarely try to
   ->releasepage() a page it is trying to handle.  The deadlock
   is removed as nfs_release_page() doesn't block indefinitely.

So we don't need to set PF_FSTRANS for sunrpc network operations any
more.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
NeilBrown 2014-09-24 11:28:32 +10:00 committed by Trond Myklebust
parent 353db79662
commit 1aff525629
4 changed files with 6 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
fs/nfs/file.c
View File

@ -476,20 +476,18 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
/* Always try to initiate a 'commit' if relevant, but only
* wait for it if __GFP_WAIT is set and the calling process is
* allowed to block. Even then, only wait 1 second and only
* if the 'bdi' is not congested.
* wait for it if __GFP_WAIT is set. Even then, only wait 1
* second and only if the 'bdi' is not congested.
* Waiting indefinitely can cause deadlocks when the NFS
* server is on this machine, and there is no particular need
* to wait extensively here. A short wait has the benefit
* that someone else can worry about the freezer.
* server is on this machine, when a new TCP connection is
* needed and in other rare cases. There is no particular
* need to wait extensively here. A short wait has the
* benefit that someone else can worry about the freezer.
*/
if (mapping) {
struct nfs_server *nfss = NFS_SERVER(mapping->host);
nfs_commit_inode(mapping->host, 0);
if ((gfp & __GFP_WAIT) &&
!current_is_kswapd() &&
!(current->flags & PF_FSTRANS) &&
!bdi_write_congested(&nfss->backing_dev_info)) {
wait_on_page_bit_killable_timeout(page, PG_private,
HZ);

2
net/sunrpc/sched.c
View File

@ -821,9 +821,7 @@ void rpc_execute(struct rpc_task *task)
static void rpc_async_schedule(struct work_struct *work)
{
current->flags |= PF_FSTRANS;
__rpc_execute(container_of(work, struct rpc_task, u.tk_work));
current->flags &= ~PF_FSTRANS;
}
/**

2
net/sunrpc/xprtrdma/transport.c
View File

@ -205,7 +205,6 @@ xprt_rdma_connect_worker(struct work_struct *work)
struct rpc_xprt *xprt = &r_xprt->xprt;
int rc = 0;
current->flags |= PF_FSTRANS;
xprt_clear_connected(xprt);
dprintk("RPC: %s: %sconnect\n", __func__,
@ -216,7 +215,6 @@ xprt_rdma_connect_worker(struct work_struct *work)
dprintk("RPC: %s: exit\n", __func__);
xprt_clear_connecting(xprt);
current->flags &= ~PF_FSTRANS;
}
/*

10
net/sunrpc/xprtsock.c
View File

@ -1954,8 +1954,6 @@ static int xs_local_setup_socket(struct sock_xprt *transport)
struct socket *sock;
int status = -EIO;
current->flags |= PF_FSTRANS;
clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
status = __sock_create(xprt->xprt_net, AF_LOCAL,
SOCK_STREAM, 0, &sock, 1);
@ -1995,7 +1993,6 @@ static int xs_local_setup_socket(struct sock_xprt *transport)
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
current->flags &= ~PF_FSTRANS;
return status;
}
@ -2098,8 +2095,6 @@ static void xs_udp_setup_socket(struct work_struct *work)
struct socket *sock = transport->sock;
int status = -EIO;
current->flags |= PF_FSTRANS;
/* Start by resetting any existing state */
xs_reset_transport(transport);
sock = xs_create_sock(xprt, transport,
@ -2119,7 +2114,6 @@ static void xs_udp_setup_socket(struct work_struct *work)
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
current->flags &= ~PF_FSTRANS;
}
/*
@ -2256,8 +2250,6 @@ static void xs_tcp_setup_socket(struct work_struct *work)
struct rpc_xprt *xprt = &transport->xprt;
int status = -EIO;
current->flags |= PF_FSTRANS;
if (!sock) {
clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
sock = xs_create_sock(xprt, transport,
@ -2305,7 +2297,6 @@ static void xs_tcp_setup_socket(struct work_struct *work)
case -EINPROGRESS:
case -EALREADY:
xprt_clear_connecting(xprt);
current->flags &= ~PF_FSTRANS;
return;
case -EINVAL:
/* Happens, for instance, if the user specified a link
@ -2323,7 +2314,6 @@ out_eagain:
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
current->flags &= ~PF_FSTRANS;
}
/**