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nfs: enable swap on NFS

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Implement the new swapfile a_ops for NFS and hook up ->direct_IO.  This
will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under
PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol
->connect() method.

PF_MEMALLOC should allow the allocation of struct socket and related
objects and the early (re)setting of SOCK_MEMALLOC should allow us to
receive the packets required for the TCP connection buildup.

[jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases]
[dfeng@redhat.com: Fix handling of multiple swap files]
[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2012-07-31 16:45:12 -07:00 committed by Linus Torvalds
parent 29418aa4bd
commit a564b8f039
9 changed files with 149 additions and 34 deletions
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8
fs/nfs/Kconfig
View file

@ -86,6 +86,14 @@ config NFS_V4
If unsure, say Y.
config NFS_SWAP
bool "Provide swap over NFS support"
default n
depends on NFS_FS
select SUNRPC_SWAP
help
This option enables swapon to work on files located on NFS mounts.
config NFS_V4_1
bool "NFS client support for NFSv4.1 (EXPERIMENTAL)"
depends on NFS_V4 && EXPERIMENTAL

82
fs/nfs/direct.c
View file

@ -115,17 +115,28 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
* @nr_segs: size of iovec array
*
* The presence of this routine in the address space ops vector means
* the NFS client supports direct I/O. However, we shunt off direct
* read and write requests before the VFS gets them, so this method
* should never be called.
* the NFS client supports direct I/O. However, for most direct IO, we
* shunt off direct read and write requests before the VFS gets them,
* so this method is only ever called for swap.
*/
ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs)
{
#ifndef CONFIG_NFS_SWAP
dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n",
iocb->ki_filp->f_path.dentry->d_name.name,
(long long) pos, nr_segs);
return -EINVAL;
#else
VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
if (rw == READ || rw == KERNEL_READ)
return nfs_file_direct_read(iocb, iov, nr_segs, pos,
rw == READ ? true : false);
return nfs_file_direct_write(iocb, iov, nr_segs, pos,
rw == WRITE ? true : false);
#endif /* CONFIG_NFS_SWAP */
}
static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
@ -303,7 +314,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
*/
static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc,
const struct iovec *iov,
loff_t pos)
loff_t pos, bool uio)
{
struct nfs_direct_req *dreq = desc->pg_dreq;
struct nfs_open_context *ctx = dreq->ctx;
@ -331,12 +342,20 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
GFP_KERNEL);
if (!pagevec)
break;
down_read(&current->mm->mmap_sem);
result = get_user_pages(current, current->mm, user_addr,
if (uio) {
down_read(&current->mm->mmap_sem);
result = get_user_pages(current, current->mm, user_addr,
npages, 1, 0, pagevec, NULL);
up_read(&current->mm->mmap_sem);
if (result < 0)
break;
up_read(&current->mm->mmap_sem);
if (result < 0)
break;
} else {
WARN_ON(npages != 1);
result = get_kernel_page(user_addr, 1, pagevec);
if (WARN_ON(result != 1))
break;
}
if ((unsigned)result < npages) {
bytes = result * PAGE_SIZE;
if (bytes <= pgbase) {
@ -386,7 +405,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
const struct iovec *iov,
unsigned long nr_segs,
loff_t pos)
loff_t pos, bool uio)
{
struct nfs_pageio_descriptor desc;
ssize_t result = -EINVAL;
@ -400,7 +419,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
result = nfs_direct_read_schedule_segment(&desc, vec, pos);
result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio);
if (result < 0)
break;
requested_bytes += result;
@ -426,7 +445,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
}
static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
unsigned long nr_segs, loff_t pos, bool uio)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@ -444,7 +463,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos);
result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);
if (!result)
result = nfs_direct_wait(dreq);
NFS_I(inode)->read_io += result;
@ -610,7 +629,7 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
*/
static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc,
const struct iovec *iov,
loff_t pos)
loff_t pos, bool uio)
{
struct nfs_direct_req *dreq = desc->pg_dreq;
struct nfs_open_context *ctx = dreq->ctx;
@ -638,12 +657,19 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
if (!pagevec)
break;
down_read(&current->mm->mmap_sem);
result = get_user_pages(current, current->mm, user_addr,
npages, 0, 0, pagevec, NULL);
up_read(&current->mm->mmap_sem);
if (result < 0)
break;
if (uio) {
down_read(&current->mm->mmap_sem);
result = get_user_pages(current, current->mm, user_addr,
npages, 0, 0, pagevec, NULL);
up_read(&current->mm->mmap_sem);
if (result < 0)
break;
} else {
WARN_ON(npages != 1);
result = get_kernel_page(user_addr, 0, pagevec);
if (WARN_ON(result != 1))
break;
}
if ((unsigned)result < npages) {
bytes = result * PAGE_SIZE;
@ -774,7 +800,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
const struct iovec *iov,
unsigned long nr_segs,
loff_t pos)
loff_t pos, bool uio)
{
struct nfs_pageio_descriptor desc;
struct inode *inode = dreq->inode;
@ -790,7 +816,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
result = nfs_direct_write_schedule_segment(&desc, vec, pos);
result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
if (result < 0)
break;
requested_bytes += result;
@ -818,7 +844,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos,
size_t count)
size_t count, bool uio)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@ -836,7 +862,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos);
result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio);
if (!result)
result = nfs_direct_wait(dreq);
out_release:
@ -867,7 +893,7 @@ out:
* cache.
*/
ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
unsigned long nr_segs, loff_t pos, bool uio)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
@ -892,7 +918,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
task_io_account_read(count);
retval = nfs_direct_read(iocb, iov, nr_segs, pos);
retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio);
if (retval > 0)
iocb->ki_pos = pos + retval;
@ -923,7 +949,7 @@ out:
* is no atomic O_APPEND write facility in the NFS protocol.
*/
ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
unsigned long nr_segs, loff_t pos, bool uio)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
@ -955,7 +981,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
task_io_account_write(count);
retval = nfs_direct_write(iocb, iov, nr_segs, pos, count);
retval = nfs_direct_write(iocb, iov, nr_segs, pos, count, uio);
if (retval > 0) {
struct inode *inode = mapping->host;

22
fs/nfs/file.c
View file

@ -175,7 +175,7 @@ nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
ssize_t result;
if (iocb->ki_filp->f_flags & O_DIRECT)
return nfs_file_direct_read(iocb, iov, nr_segs, pos);
return nfs_file_direct_read(iocb, iov, nr_segs, pos, true);
dprintk("NFS: read(%s/%s, %lu@%lu)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
@ -482,6 +482,20 @@ static int nfs_launder_page(struct page *page)
return nfs_wb_page(inode, page);
}
#ifdef CONFIG_NFS_SWAP
static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
*span = sis->pages;
return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 1);
}
static void nfs_swap_deactivate(struct file *file)
{
xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 0);
}
#endif
const struct address_space_operations nfs_file_aops = {
.readpage = nfs_readpage,
.readpages = nfs_readpages,
@ -496,6 +510,10 @@ const struct address_space_operations nfs_file_aops = {
.migratepage = nfs_migrate_page,
.launder_page = nfs_launder_page,
.error_remove_page = generic_error_remove_page,
#ifdef CONFIG_NFS_SWAP
.swap_activate = nfs_swap_activate,
.swap_deactivate = nfs_swap_deactivate,
#endif
};
/*
@ -570,7 +588,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
size_t count = iov_length(iov, nr_segs);
if (iocb->ki_filp->f_flags & O_DIRECT)
return nfs_file_direct_write(iocb, iov, nr_segs, pos);
return nfs_file_direct_write(iocb, iov, nr_segs, pos, true);
dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,

4
include/linux/nfs_fs.h
View file

@ -473,10 +473,10 @@ extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
unsigned long);
extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
const struct iovec *iov, unsigned long nr_segs,
loff_t pos);
loff_t pos, bool uio);
extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
const struct iovec *iov, unsigned long nr_segs,
loff_t pos);
loff_t pos, bool uio);
/*
* linux/fs/nfs/dir.c

3
include/linux/sunrpc/xprt.h
View file

@ -174,6 +174,8 @@ struct rpc_xprt {
unsigned long state; /* transport state */
unsigned char shutdown : 1, /* being shut down */
resvport : 1; /* use a reserved port */
unsigned int swapper; /* we're swapping over this
transport */
unsigned int bind_index; /* bind function index */
/*
@ -316,6 +318,7 @@ void xprt_release_rqst_cong(struct rpc_task *task);
void xprt_disconnect_done(struct rpc_xprt *xprt);
void xprt_force_disconnect(struct rpc_xprt *xprt);
void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
int xs_swapper(struct rpc_xprt *xprt, int enable);
/*
* Reserved bit positions in xprt->state

5
net/sunrpc/Kconfig
View file

@ -21,6 +21,11 @@ config SUNRPC_XPRT_RDMA
If unsure, say N.
config SUNRPC_SWAP
bool
depends on SUNRPC
select NETVM
config RPCSEC_GSS_KRB5
tristate "Secure RPC: Kerberos V mechanism"
depends on SUNRPC && CRYPTO

9
net/sunrpc/clnt.c
View file

@ -717,6 +717,15 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
atomic_inc(&clnt->cl_count);
if (clnt->cl_softrtry)
task->tk_flags |= RPC_TASK_SOFT;
if (sk_memalloc_socks()) {
struct rpc_xprt *xprt;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
if (xprt->swapper)
task->tk_flags |= RPC_TASK_SWAPPER;
rcu_read_unlock();
}
/* Add to the client's list of all tasks */
spin_lock(&clnt->cl_lock);
list_add_tail(&task->tk_task, &clnt->cl_tasks);

7
net/sunrpc/sched.c
View file

@ -812,7 +812,10 @@ static void rpc_async_schedule(struct work_struct *work)
void *rpc_malloc(struct rpc_task *task, size_t size)
{
struct rpc_buffer *buf;
gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
gfp_t gfp = GFP_NOWAIT;
if (RPC_IS_SWAPPER(task))
gfp |= __GFP_MEMALLOC;
size += sizeof(struct rpc_buffer);
if (size <= RPC_BUFFER_MAXSIZE)
@ -886,7 +889,7 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta
static struct rpc_task *
rpc_alloc_task(void)
{
return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOIO);
}
/*

43
net/sunrpc/xprtsock.c
View file

@ -1927,6 +1927,45 @@ out:
xprt_wake_pending_tasks(xprt, status);
}
#ifdef CONFIG_SUNRPC_SWAP
static void xs_set_memalloc(struct rpc_xprt *xprt)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
xprt);
if (xprt->swapper)
sk_set_memalloc(transport->inet);
}
/**
* xs_swapper - Tag this transport as being used for swap.
* @xprt: transport to tag
* @enable: enable/disable
*
*/
int xs_swapper(struct rpc_xprt *xprt, int enable)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
xprt);
int err = 0;
if (enable) {
xprt->swapper++;
xs_set_memalloc(xprt);
} else if (xprt->swapper) {
xprt->swapper--;
sk_clear_memalloc(transport->inet);
}
return err;
}
EXPORT_SYMBOL_GPL(xs_swapper);
#else
static void xs_set_memalloc(struct rpc_xprt *xprt)
{
}
#endif
static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
@ -1951,6 +1990,8 @@ static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
transport->sock = sock;
transport->inet = sk;
xs_set_memalloc(xprt);
write_unlock_bh(&sk->sk_callback_lock);
}
xs_udp_do_set_buffer_size(xprt);
@ -2075,6 +2116,8 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
if (!xprt_bound(xprt))
goto out;
xs_set_memalloc(xprt);
/* Tell the socket layer to start connecting... */
xprt->stat.connect_count++;
xprt->stat.connect_start = jiffies;