* [PATCH 00/12] Swap-over-NFS without deadlocking V8
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
Changelog since V7
o Rebase to linux-next 20120629
o bi->page_dma instead of bi->page in intel driver
o Build fix for !CONFIG_NET (sebastian)
o Restore PF_MEMALLOC flags correctly in all cases (jlayton)
Changelog since V6
o Rebase to linux-next 20120622
Changelog since V5
o Rebase to v3.5-rc3
Changelog since V4
o Catch if SOCK_MEMALLOC flag is cleared with rmem tokens (davem)
Changelog since V3
o Rebase to 3.4-rc5
o kmap pages for writing to swap (akpm)
o Move forward declaration to reduce chance of duplication (akpm)
Changelog since V2
o Nothing significant, just rebases. A radix tree lookup is replaced with
a linear search would be the biggest rebase artifact
This patch series is based on top of "Swap-over-NBD without deadlocking v14"
as it depends on the same reservation of PF_MEMALLOC reserves logic.
When a user or administrator requires swap for their application, they
create a swap partition and file, format it with mkswap and activate it with
swapon. In diskless systems this is not an option so if swap if required
then swapping over the network is considered. The two likely scenarios
are when blade servers are used as part of a cluster where the form factor
or maintenance costs do not allow the use of disks and thin clients.
The Linux Terminal Server Project recommends the use of the Network
Block Device (NBD) for swap but this is not always an option. There is
no guarantee that the network attached storage (NAS) device is running
Linux or supports NBD. However, it is likely that it supports NFS so there
are users that want support for swapping over NFS despite any performance
concern. Some distributions currently carry patches that support swapping
over NFS but it would be preferable to support it in the mainline kernel.
Patch 1 avoids a stream-specific deadlock that potentially affects TCP.
Patch 2 is a small modification to SELinux to avoid using PFMEMALLOC
reserves.
Patch 3 adds three helpers for filesystems to handle swap cache pages.
For example, page_file_mapping() returns page->mapping for
file-backed pages and the address_space of the underlying
swap file for swap cache pages.
Patch 4 adds two address_space_operations to allow a filesystem
to pin all metadata relevant to a swapfile in memory. Upon
successful activation, the swapfile is marked SWP_FILE and
the address space operation ->direct_IO is used for writing
and ->readpage for reading in swap pages.
Patch 5 notes that patch 3 is bolting
filesystem-specific-swapfile-support onto the side and that
the default handlers have different information to what
is available to the filesystem. This patch refactors the
code so that there are generic handlers for each of the new
address_space operations.
Patch 6 adds an API to allow a vector of kernel addresses to be
translated to struct pages and pinned for IO.
Patch 7 adds support for using highmem pages for swap by kmapping
the pages before calling the direct_IO handler.
Patch 8 updates NFS to use the helpers from patch 3 where necessary.
Patch 9 avoids setting PF_private on PG_swapcache pages within NFS.
Patch 10 implements the new swapfile-related address_space operations
for NFS and teaches the direct IO handler how to manage
kernel addresses.
Patch 11 prevents page allocator recursions in NFS by using GFP_NOIO
where appropriate.
Patch 12 fixes a NULL pointer dereference that occurs when using
swap-over-NFS.
With the patches applied, it is possible to mount a swapfile that is on an
NFS filesystem. Swap performance is not great with a swap stress test taking
roughly twice as long to complete than if the swap device was backed by NBD.
Documentation/filesystems/Locking | 13 ++++
Documentation/filesystems/vfs.txt | 12 +++
fs/nfs/Kconfig | 8 ++
fs/nfs/direct.c | 82 ++++++++++++++-------
fs/nfs/file.c | 28 +++++--
fs/nfs/inode.c | 4 +
fs/nfs/internal.h | 7 +-
fs/nfs/pagelist.c | 4 +-
fs/nfs/read.c | 6 +-
fs/nfs/write.c | 91 ++++++++++++++---------
include/linux/blk_types.h | 2 +
include/linux/fs.h | 8 ++
include/linux/highmem.h | 7 ++
include/linux/mm.h | 29 ++++++++
include/linux/nfs_fs.h | 4 +-
include/linux/pagemap.h | 5 ++
include/linux/sunrpc/xprt.h | 3 +
include/linux/swap.h | 8 ++
include/net/sock.h | 8 +-
mm/highmem.c | 12 +++
mm/memory.c | 52 +++++++++++++
mm/page_io.c | 145 +++++++++++++++++++++++++++++++++++++
mm/swap_state.c | 2 +-
mm/swapfile.c | 141 ++++++++++++++----------------------
net/caif/caif_socket.c | 2 +-
net/core/sock.c | 14 +++-
net/ipv4/tcp_input.c | 21 +++---
net/sctp/ulpevent.c | 3 +-
net/sunrpc/Kconfig | 5 ++
net/sunrpc/clnt.c | 2 +
net/sunrpc/sched.c | 7 +-
net/sunrpc/xprtsock.c | 54 ++++++++++++++
security/selinux/avc.c | 2 +-
33 files changed, 605 insertions(+), 186 deletions(-)
--
1.7.9.2
--
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^ permalink raw reply
* [PATCH 01/12] netvm: Prevent a stream-specific deadlock
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
It could happen that all !SOCK_MEMALLOC sockets have buffered so
much data that we're over the global rmem limit. This will prevent
SOCK_MEMALLOC buffers from receiving data, which will prevent userspace
from running, which is needed to reduce the buffered data.
Fix this by exempting the SOCK_MEMALLOC sockets from the rmem limit.
Once this change it applied, it is important that sockets that set
SOCK_MEMALLOC do not clear the flag until the socket is being torn down.
If this happens, a warning is generated and the tokens reclaimed to
avoid accounting errors until the bug is fixed.
[davem@davemloft.net: Warning about clearing SOCK_MEMALLOC]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Rik van Riel<riel@redhat.com>
---
include/net/sock.h | 8 +++++---
net/caif/caif_socket.c | 2 +-
net/core/sock.c | 14 +++++++++++++-
net/ipv4/tcp_input.c | 21 +++++++++++----------
net/sctp/ulpevent.c | 3 ++-
5 files changed, 32 insertions(+), 16 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index 767c443..5faae49 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1326,12 +1326,14 @@ static inline bool sk_wmem_schedule(struct sock *sk, int size)
__sk_mem_schedule(sk, size, SK_MEM_SEND);
}
-static inline bool sk_rmem_schedule(struct sock *sk, int size)
+static inline bool
+sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, unsigned int size)
{
if (!sk_has_account(sk))
return true;
- return size <= sk->sk_forward_alloc ||
- __sk_mem_schedule(sk, size, SK_MEM_RECV);
+ return size<= sk->sk_forward_alloc ||
+ __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
+ skb_pfmemalloc(skb);
}
static inline void sk_mem_reclaim(struct sock *sk)
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 78f1cda..095259f 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -141,7 +141,7 @@ static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
err = sk_filter(sk, skb);
if (err)
return err;
- if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
+ if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
set_rx_flow_off(cf_sk);
net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
diff --git a/net/core/sock.c b/net/core/sock.c
index c551563..5cbca0e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -295,6 +295,18 @@ void sk_clear_memalloc(struct sock *sk)
sock_reset_flag(sk, SOCK_MEMALLOC);
sk->sk_allocation &= ~__GFP_MEMALLOC;
static_key_slow_dec(&memalloc_socks);
+
+ /*
+ * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
+ * progress of swapping. However, if SOCK_MEMALLOC is cleared while
+ * it has rmem allocations there is a risk that the user of the
+ * socket cannot make forward progress due to exceeding the rmem
+ * limits. By rights, sk_clear_memalloc() should only be called
+ * on sockets being torn down but warn and reset the accounting if
+ * that assumption breaks.
+ */
+ if (WARN_ON(sk->sk_forward_alloc))
+ sk_mem_reclaim(sk);
}
EXPORT_SYMBOL_GPL(sk_clear_memalloc);
@@ -396,7 +408,7 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (err)
return err;
- if (!sk_rmem_schedule(sk, skb->truesize)) {
+ if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
atomic_inc(&sk->sk_drops);
return -ENOBUFS;
}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8416f8a..7d6ff91 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4512,19 +4512,20 @@ static void tcp_ofo_queue(struct sock *sk)
static bool tcp_prune_ofo_queue(struct sock *sk);
static int tcp_prune_queue(struct sock *sk);
-static int tcp_try_rmem_schedule(struct sock *sk, unsigned int size)
+static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb,
+ unsigned int size)
{
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
- !sk_rmem_schedule(sk, size)) {
+ !sk_rmem_schedule(sk, skb, size)) {
if (tcp_prune_queue(sk) < 0)
return -1;
- if (!sk_rmem_schedule(sk, size)) {
+ if (!sk_rmem_schedule(sk, skb, size)) {
if (!tcp_prune_ofo_queue(sk))
return -1;
- if (!sk_rmem_schedule(sk, size))
+ if (!sk_rmem_schedule(sk, skb, size))
return -1;
}
}
@@ -4579,7 +4580,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
TCP_ECN_check_ce(tp, skb);
- if (tcp_try_rmem_schedule(sk, skb->truesize)) {
+ if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) {
/* TODO: should increment a counter */
__kfree_skb(skb);
return;
@@ -4710,17 +4711,17 @@ static int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, int
int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
{
- struct sk_buff *skb;
+ struct sk_buff *skb = NULL;
struct tcphdr *th;
bool fragstolen;
- if (tcp_try_rmem_schedule(sk, size + sizeof(*th)))
- goto err;
-
skb = alloc_skb(size + sizeof(*th), sk->sk_allocation);
if (!skb)
goto err;
+ if (tcp_try_rmem_schedule(sk, skb, size + sizeof(*th)))
+ goto err_free;
+
th = (struct tcphdr *)skb_put(skb, sizeof(*th));
skb_reset_transport_header(skb);
memset(th, 0, sizeof(*th));
@@ -4791,7 +4792,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
if (eaten <= 0) {
queue_and_out:
if (eaten < 0 &&
- tcp_try_rmem_schedule(sk, skb->truesize))
+ tcp_try_rmem_schedule(sk, skb, skb->truesize))
goto drop;
eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index 8a84017..1f89add 100644
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -702,7 +702,8 @@ struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
if (rx_count >= asoc->base.sk->sk_rcvbuf) {
if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
- (!sk_rmem_schedule(asoc->base.sk, chunk->skb->truesize)))
+ (!sk_rmem_schedule(asoc->base.sk, chunk->skb,
+ chunk->skb->truesize)))
goto fail;
}
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 02/12] selinux: tag avc cache alloc as non-critical
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
Failing to allocate a cache entry will only harm performance not
correctness. Do not consume valuable reserve pages for something
like that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
---
security/selinux/avc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 68d82da..4d3fab4 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -274,7 +274,7 @@ static struct avc_node *avc_alloc_node(void)
{
struct avc_node *node;
- node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC);
+ node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC|__GFP_NOMEMALLOC);
if (!node)
goto out;
--
1.7.9.2
--
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the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related
* [PATCH 03/12] mm: Methods for teaching filesystems about PG_swapcache pages
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
In order to teach filesystems to handle swap cache pages, three new
page functions are introduced:
pgoff_t page_file_index(struct page *);
loff_t page_file_offset(struct page *);
struct address_space *page_file_mapping(struct page *);
page_file_index() - gives the offset of this page in the file in
PAGE_CACHE_SIZE blocks. Like page->index is for mapped pages, this
function also gives the correct index for PG_swapcache pages.
page_file_offset() - uses page_file_index(), so that it will give
the expected result, even for PG_swapcache pages.
page_file_mapping() - gives the mapping backing the actual page;
that is for swap cache pages it will give swap_file->f_mapping.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
---
include/linux/mm.h | 25 +++++++++++++++++++++++++
include/linux/pagemap.h | 5 +++++
mm/swapfile.c | 19 +++++++++++++++++++
3 files changed, 49 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a4549c6..b3d4cd9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -805,6 +805,17 @@ static inline void *page_rmapping(struct page *page)
return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
}
+extern struct address_space *__page_file_mapping(struct page *);
+
+static inline
+struct address_space *page_file_mapping(struct page *page)
+{
+ if (unlikely(PageSwapCache(page)))
+ return __page_file_mapping(page);
+
+ return page->mapping;
+}
+
static inline int PageAnon(struct page *page)
{
return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
@@ -821,6 +832,20 @@ static inline pgoff_t page_index(struct page *page)
return page->index;
}
+extern pgoff_t __page_file_index(struct page *page);
+
+/*
+ * Return the file index of the page. Regular pagecache pages use ->index
+ * whereas swapcache pages use swp_offset(->private)
+ */
+static inline pgoff_t page_file_index(struct page *page)
+{
+ if (unlikely(PageSwapCache(page)))
+ return __page_file_index(page);
+
+ return page->index;
+}
+
/*
* Return true if this page is mapped into pagetables.
*/
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 7cfad3b..e42c762 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -286,6 +286,11 @@ static inline loff_t page_offset(struct page *page)
return ((loff_t)page->index) << PAGE_CACHE_SHIFT;
}
+static inline loff_t page_file_offset(struct page *page)
+{
+ return ((loff_t)page_file_index(page)) << PAGE_CACHE_SHIFT;
+}
+
extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
unsigned long address);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 64408be..f4e02bd 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -33,6 +33,7 @@
#include <linux/oom.h>
#include <linux/frontswap.h>
#include <linux/swapfile.h>
+#include <linux/export.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -2299,6 +2300,24 @@ int swapcache_prepare(swp_entry_t entry)
}
/*
+ * out-of-line __page_file_ methods to avoid include hell.
+ */
+struct address_space *__page_file_mapping(struct page *page)
+{
+ VM_BUG_ON(!PageSwapCache(page));
+ return page_swap_info(page)->swap_file->f_mapping;
+}
+EXPORT_SYMBOL_GPL(__page_file_mapping);
+
+pgoff_t __page_file_index(struct page *page)
+{
+ swp_entry_t swap = { .val = page_private(page) };
+ VM_BUG_ON(!PageSwapCache(page));
+ return swp_offset(swap);
+}
+EXPORT_SYMBOL_GPL(__page_file_index);
+
+/*
* add_swap_count_continuation - called when a swap count is duplicated
* beyond SWAP_MAP_MAX, it allocates a new page and links that to the entry's
* page of the original vmalloc'ed swap_map, to hold the continuation count
--
1.7.9.2
^ permalink raw reply related
* [PATCH 04/12] mm: Add support for a filesystem to activate swap files and use direct_IO for writing swap pages
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
Currently swapfiles are managed entirely by the core VM by using ->bmap
to allocate space and write to the blocks directly. This effectively
ensures that the underlying blocks are allocated and avoids the need
for the swap subsystem to locate what physical blocks store offsets
within a file.
If the swap subsystem is to use the filesystem information to locate
the blocks, it is critical that information such as block groups,
block bitmaps and the block descriptor table that map the swap file
were resident in memory. This patch adds address_space_operations that
the VM can call when activating or deactivating swap backed by a file.
int swap_activate(struct file *);
int swap_deactivate(struct file *);
The ->swap_activate() method is used to communicate to the
file that the VM relies on it, and the address_space should take
adequate measures such as reserving space in the underlying device,
reserving memory for mempools and pinning information such as the
block descriptor table in memory. The ->swap_deactivate() method is
called on sys_swapoff() if ->swap_activate() returned success.
After a successful swapfile ->swap_activate, the swapfile
is marked SWP_FILE and swapper_space.a_ops will proxy to
sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache
pages and ->readpage to read.
It is perfectly possible that direct_IO be used to read the swap
pages but it is an unnecessary complication. Similarly, it is possible
that ->writepage be used instead of direct_io to write the pages but
filesystem developers have stated that calling writepage from the VM
is undesirable for a variety of reasons and using direct_IO opens up
the possibility of writing back batches of swap pages in the future.
[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
Documentation/filesystems/Locking | 13 ++++++++++
Documentation/filesystems/vfs.txt | 12 +++++++++
include/linux/fs.h | 4 +++
include/linux/swap.h | 3 +++
mm/page_io.c | 52 +++++++++++++++++++++++++++++++++++++
mm/swap_state.c | 2 +-
mm/swapfile.c | 30 +++++++++++++++++++--
7 files changed, 113 insertions(+), 3 deletions(-)
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index e0cce2a..2db1900 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -206,6 +206,8 @@ prototypes:
int (*launder_page)(struct page *);
int (*is_partially_uptodate)(struct page *, read_descriptor_t *, unsigned long);
int (*error_remove_page)(struct address_space *, struct page *);
+ int (*swap_activate)(struct file *);
+ int (*swap_deactivate)(struct file *);
locking rules:
All except set_page_dirty and freepage may block
@@ -229,6 +231,8 @@ migratepage: yes (both)
launder_page: yes
is_partially_uptodate: yes
error_remove_page: yes
+swap_activate: no
+swap_deactivate: no
->write_begin(), ->write_end(), ->sync_page() and ->readpage()
may be called from the request handler (/dev/loop).
@@ -330,6 +334,15 @@ cleaned, or an error value if not. Note that in order to prevent the page
getting mapped back in and redirtied, it needs to be kept locked
across the entire operation.
+ ->swap_activate will be called with a non-zero argument on
+files backing (non block device backed) swapfiles. A return value
+of zero indicates success, in which case this file can be used for
+backing swapspace. The swapspace operations will be proxied to the
+address space operations.
+
+ ->swap_deactivate() will be called in the sys_swapoff()
+path after ->swap_activate() returned success.
+
----------------------- file_lock_operations ------------------------------
prototypes:
void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index aa754e0..8aea28f 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -592,6 +592,8 @@ struct address_space_operations {
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
int (*error_remove_page) (struct mapping *mapping, struct page *page);
+ int (*swap_activate)(struct file *);
+ int (*swap_deactivate)(struct file *);
};
writepage: called by the VM to write a dirty page to backing store.
@@ -760,6 +762,16 @@ struct address_space_operations {
Setting this implies you deal with pages going away under you,
unless you have them locked or reference counts increased.
+ swap_activate: Called when swapon is used on a file to allocate
+ space if necessary and pin the block lookup information in
+ memory. A return value of zero indicates success,
+ in which case this file can be used to back swapspace. The
+ swapspace operations will be proxied to this address space's
+ ->swap_{out,in} methods.
+
+ swap_deactivate: Called during swapoff on files where swap_activate
+ was successful.
+
The File Object
===============
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3e035f4..2a6396b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -638,6 +638,10 @@ struct address_space_operations {
int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
unsigned long);
int (*error_remove_page)(struct address_space *, struct page *);
+
+ /* swapfile support */
+ int (*swap_activate)(struct file *file);
+ int (*swap_deactivate)(struct file *file);
};
extern const struct address_space_operations empty_aops;
diff --git a/include/linux/swap.h b/include/linux/swap.h
index b967eda..b236bc4 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -151,6 +151,7 @@ enum {
SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
SWP_BLKDEV = (1 << 6), /* its a block device */
+ SWP_FILE = (1 << 7), /* set after swap_activate success */
/* add others here before... */
SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
};
@@ -320,6 +321,7 @@ static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
/* linux/mm/page_io.c */
extern int swap_readpage(struct page *);
extern int swap_writepage(struct page *page, struct writeback_control *wbc);
+extern int swap_set_page_dirty(struct page *page);
extern void end_swap_bio_read(struct bio *bio, int err);
/* linux/mm/swap_state.c */
@@ -356,6 +358,7 @@ extern unsigned int count_swap_pages(int, int);
extern sector_t map_swap_page(struct page *, struct block_device **);
extern sector_t swapdev_block(int, pgoff_t);
extern int page_swapcount(struct page *);
+extern struct swap_info_struct *page_swap_info(struct page *);
extern int reuse_swap_page(struct page *);
extern int can_reuse_swap_page(struct page *);
extern int try_to_free_swap(struct page *);
diff --git a/mm/page_io.c b/mm/page_io.c
index 34f0292..307a3e7 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -17,6 +17,7 @@
#include <linux/swap.h>
#include <linux/bio.h>
#include <linux/swapops.h>
+#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/frontswap.h>
#include <asm/pgtable.h>
@@ -94,6 +95,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
{
struct bio *bio;
int ret = 0, rw = WRITE;
+ struct swap_info_struct *sis = page_swap_info(page);
if (try_to_free_swap(page)) {
unlock_page(page);
@@ -105,6 +107,32 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
end_page_writeback(page);
goto out;
}
+
+ if (sis->flags & SWP_FILE) {
+ struct kiocb kiocb;
+ struct file *swap_file = sis->swap_file;
+ struct address_space *mapping = swap_file->f_mapping;
+ struct iovec iov = {
+ .iov_base = page_address(page),
+ .iov_len = PAGE_SIZE,
+ };
+
+ init_sync_kiocb(&kiocb, swap_file);
+ kiocb.ki_pos = page_file_offset(page);
+ kiocb.ki_left = PAGE_SIZE;
+ kiocb.ki_nbytes = PAGE_SIZE;
+
+ unlock_page(page);
+ ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
+ &kiocb, &iov,
+ kiocb.ki_pos, 1);
+ if (ret == PAGE_SIZE) {
+ count_vm_event(PSWPOUT);
+ ret = 0;
+ }
+ return ret;
+ }
+
bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
if (bio == NULL) {
set_page_dirty(page);
@@ -126,6 +154,7 @@ int swap_readpage(struct page *page)
{
struct bio *bio;
int ret = 0;
+ struct swap_info_struct *sis = page_swap_info(page);
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(PageUptodate(page));
@@ -134,6 +163,17 @@ int swap_readpage(struct page *page)
unlock_page(page);
goto out;
}
+
+ if (sis->flags & SWP_FILE) {
+ struct file *swap_file = sis->swap_file;
+ struct address_space *mapping = swap_file->f_mapping;
+
+ ret = mapping->a_ops->readpage(swap_file, page);
+ if (!ret)
+ count_vm_event(PSWPIN);
+ return ret;
+ }
+
bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
if (bio == NULL) {
unlock_page(page);
@@ -145,3 +185,15 @@ int swap_readpage(struct page *page)
out:
return ret;
}
+
+int swap_set_page_dirty(struct page *page)
+{
+ struct swap_info_struct *sis = page_swap_info(page);
+
+ if (sis->flags & SWP_FILE) {
+ struct address_space *mapping = sis->swap_file->f_mapping;
+ return mapping->a_ops->set_page_dirty(page);
+ } else {
+ return __set_page_dirty_no_writeback(page);
+ }
+}
diff --git a/mm/swap_state.c b/mm/swap_state.c
index c85b559..0cb36fb 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -27,7 +27,7 @@
*/
static const struct address_space_operations swap_aops = {
.writepage = swap_writepage,
- .set_page_dirty = __set_page_dirty_no_writeback,
+ .set_page_dirty = swap_set_page_dirty,
.migratepage = migrate_page,
};
diff --git a/mm/swapfile.c b/mm/swapfile.c
index f4e02bd..b8b5861 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1342,6 +1342,14 @@ static void destroy_swap_extents(struct swap_info_struct *sis)
list_del(&se->list);
kfree(se);
}
+
+ if (sis->flags & SWP_FILE) {
+ struct file *swap_file = sis->swap_file;
+ struct address_space *mapping = swap_file->f_mapping;
+
+ sis->flags &= ~SWP_FILE;
+ mapping->a_ops->swap_deactivate(swap_file);
+ }
}
/*
@@ -1423,7 +1431,9 @@ add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
*/
static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
{
- struct inode *inode;
+ struct file *swap_file = sis->swap_file;
+ struct address_space *mapping = swap_file->f_mapping;
+ struct inode *inode = mapping->host;
unsigned blocks_per_page;
unsigned long page_no;
unsigned blkbits;
@@ -1434,13 +1444,22 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
int nr_extents = 0;
int ret;
- inode = sis->swap_file->f_mapping->host;
if (S_ISBLK(inode->i_mode)) {
ret = add_swap_extent(sis, 0, sis->max, 0);
*span = sis->pages;
goto out;
}
+ if (mapping->a_ops->swap_activate) {
+ ret = mapping->a_ops->swap_activate(swap_file);
+ if (!ret) {
+ sis->flags |= SWP_FILE;
+ ret = add_swap_extent(sis, 0, sis->max, 0);
+ *span = sis->pages;
+ }
+ goto out;
+ }
+
blkbits = inode->i_blkbits;
blocks_per_page = PAGE_SIZE >> blkbits;
@@ -2299,6 +2318,13 @@ int swapcache_prepare(swp_entry_t entry)
return __swap_duplicate(entry, SWAP_HAS_CACHE);
}
+struct swap_info_struct *page_swap_info(struct page *page)
+{
+ swp_entry_t swap = { .val = page_private(page) };
+ BUG_ON(!PageSwapCache(page));
+ return swap_info[swp_type(swap)];
+}
+
/*
* out-of-line __page_file_ methods to avoid include hell.
*/
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 05/12] mm: swap: Implement generic handler for swap_activate
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
The version of swap_activate introduced is sufficient for swap-over-NFS
but would not provide enough information to implement a generic handler.
This patch shuffles things slightly to ensure the same information is
available for aops->swap_activate() as is available to the core.
No functionality change.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
include/linux/fs.h | 6 ++--
include/linux/swap.h | 5 +++
mm/page_io.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
mm/swapfile.c | 91 +++----------------------------------------------
4 files changed, 106 insertions(+), 88 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2a6396b..006aa85 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -427,6 +427,7 @@ struct kstatfs;
struct vm_area_struct;
struct vfsmount;
struct cred;
+struct swap_info_struct;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
@@ -640,8 +641,9 @@ struct address_space_operations {
int (*error_remove_page)(struct address_space *, struct page *);
/* swapfile support */
- int (*swap_activate)(struct file *file);
- int (*swap_deactivate)(struct file *file);
+ int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
+ sector_t *span);
+ void (*swap_deactivate)(struct file *file);
};
extern const struct address_space_operations empty_aops;
diff --git a/include/linux/swap.h b/include/linux/swap.h
index b236bc4..57f4858 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -324,6 +324,11 @@ extern int swap_writepage(struct page *page, struct writeback_control *wbc);
extern int swap_set_page_dirty(struct page *page);
extern void end_swap_bio_read(struct bio *bio, int err);
+int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
+ unsigned long nr_pages, sector_t start_block);
+int generic_swapfile_activate(struct swap_info_struct *, struct file *,
+ sector_t *);
+
/* linux/mm/swap_state.c */
extern struct address_space swapper_space;
#define total_swapcache_pages swapper_space.nrpages
diff --git a/mm/page_io.c b/mm/page_io.c
index 307a3e7..4a37962 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -87,6 +87,98 @@ void end_swap_bio_read(struct bio *bio, int err)
bio_put(bio);
}
+int generic_swapfile_activate(struct swap_info_struct *sis,
+ struct file *swap_file,
+ sector_t *span)
+{
+ struct address_space *mapping = swap_file->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned blocks_per_page;
+ unsigned long page_no;
+ unsigned blkbits;
+ sector_t probe_block;
+ sector_t last_block;
+ sector_t lowest_block = -1;
+ sector_t highest_block = 0;
+ int nr_extents = 0;
+ int ret;
+
+ blkbits = inode->i_blkbits;
+ blocks_per_page = PAGE_SIZE >> blkbits;
+
+ /*
+ * Map all the blocks into the extent list. This code doesn't try
+ * to be very smart.
+ */
+ probe_block = 0;
+ page_no = 0;
+ last_block = i_size_read(inode) >> blkbits;
+ while ((probe_block + blocks_per_page) <= last_block &&
+ page_no < sis->max) {
+ unsigned block_in_page;
+ sector_t first_block;
+
+ first_block = bmap(inode, probe_block);
+ if (first_block == 0)
+ goto bad_bmap;
+
+ /*
+ * It must be PAGE_SIZE aligned on-disk
+ */
+ if (first_block & (blocks_per_page - 1)) {
+ probe_block++;
+ goto reprobe;
+ }
+
+ for (block_in_page = 1; block_in_page < blocks_per_page;
+ block_in_page++) {
+ sector_t block;
+
+ block = bmap(inode, probe_block + block_in_page);
+ if (block == 0)
+ goto bad_bmap;
+ if (block != first_block + block_in_page) {
+ /* Discontiguity */
+ probe_block++;
+ goto reprobe;
+ }
+ }
+
+ first_block >>= (PAGE_SHIFT - blkbits);
+ if (page_no) { /* exclude the header page */
+ if (first_block < lowest_block)
+ lowest_block = first_block;
+ if (first_block > highest_block)
+ highest_block = first_block;
+ }
+
+ /*
+ * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
+ */
+ ret = add_swap_extent(sis, page_no, 1, first_block);
+ if (ret < 0)
+ goto out;
+ nr_extents += ret;
+ page_no++;
+ probe_block += blocks_per_page;
+reprobe:
+ continue;
+ }
+ ret = nr_extents;
+ *span = 1 + highest_block - lowest_block;
+ if (page_no == 0)
+ page_no = 1; /* force Empty message */
+ sis->max = page_no;
+ sis->pages = page_no - 1;
+ sis->highest_bit = page_no - 1;
+out:
+ return ret;
+bad_bmap:
+ printk(KERN_ERR "swapon: swapfile has holes\n");
+ ret = -EINVAL;
+ goto out;
+}
+
/*
* We may have stale swap cache pages in memory: notice
* them here and get rid of the unnecessary final write.
diff --git a/mm/swapfile.c b/mm/swapfile.c
index b8b5861..1d77b13 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1358,7 +1358,7 @@ static void destroy_swap_extents(struct swap_info_struct *sis)
*
* This function rather assumes that it is called in ascending page order.
*/
-static int
+int
add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
unsigned long nr_pages, sector_t start_block)
{
@@ -1434,106 +1434,25 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
struct file *swap_file = sis->swap_file;
struct address_space *mapping = swap_file->f_mapping;
struct inode *inode = mapping->host;
- unsigned blocks_per_page;
- unsigned long page_no;
- unsigned blkbits;
- sector_t probe_block;
- sector_t last_block;
- sector_t lowest_block = -1;
- sector_t highest_block = 0;
- int nr_extents = 0;
int ret;
if (S_ISBLK(inode->i_mode)) {
ret = add_swap_extent(sis, 0, sis->max, 0);
*span = sis->pages;
- goto out;
+ return ret;
}
if (mapping->a_ops->swap_activate) {
- ret = mapping->a_ops->swap_activate(swap_file);
+ ret = mapping->a_ops->swap_activate(sis, swap_file, span);
if (!ret) {
sis->flags |= SWP_FILE;
ret = add_swap_extent(sis, 0, sis->max, 0);
*span = sis->pages;
}
- goto out;
+ return ret;
}
- blkbits = inode->i_blkbits;
- blocks_per_page = PAGE_SIZE >> blkbits;
-
- /*
- * Map all the blocks into the extent list. This code doesn't try
- * to be very smart.
- */
- probe_block = 0;
- page_no = 0;
- last_block = i_size_read(inode) >> blkbits;
- while ((probe_block + blocks_per_page) <= last_block &&
- page_no < sis->max) {
- unsigned block_in_page;
- sector_t first_block;
-
- first_block = bmap(inode, probe_block);
- if (first_block == 0)
- goto bad_bmap;
-
- /*
- * It must be PAGE_SIZE aligned on-disk
- */
- if (first_block & (blocks_per_page - 1)) {
- probe_block++;
- goto reprobe;
- }
-
- for (block_in_page = 1; block_in_page < blocks_per_page;
- block_in_page++) {
- sector_t block;
-
- block = bmap(inode, probe_block + block_in_page);
- if (block == 0)
- goto bad_bmap;
- if (block != first_block + block_in_page) {
- /* Discontiguity */
- probe_block++;
- goto reprobe;
- }
- }
-
- first_block >>= (PAGE_SHIFT - blkbits);
- if (page_no) { /* exclude the header page */
- if (first_block < lowest_block)
- lowest_block = first_block;
- if (first_block > highest_block)
- highest_block = first_block;
- }
-
- /*
- * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
- */
- ret = add_swap_extent(sis, page_no, 1, first_block);
- if (ret < 0)
- goto out;
- nr_extents += ret;
- page_no++;
- probe_block += blocks_per_page;
-reprobe:
- continue;
- }
- ret = nr_extents;
- *span = 1 + highest_block - lowest_block;
- if (page_no == 0)
- page_no = 1; /* force Empty message */
- sis->max = page_no;
- sis->pages = page_no - 1;
- sis->highest_bit = page_no - 1;
-out:
- return ret;
-bad_bmap:
- printk(KERN_ERR "swapon: swapfile has holes\n");
- ret = -EINVAL;
- goto out;
+ return generic_swapfile_activate(sis, swap_file, span);
}
static void enable_swap_info(struct swap_info_struct *p, int prio,
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 06/12] mm: Add get_kernel_page[s] for pinning of kernel addresses for I/O
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
This patch adds two new APIs get_kernel_pages() and get_kernel_page()
that may be used to pin a vector of kernel addresses for IO. The initial
user is expected to be NFS for allowing pages to be written to swap
using aops->direct_IO(). Strictly speaking, swap-over-NFS only needs
to pin one page for IO but it makes sense to express the API in terms
of a vector and add a helper for pinning single pages.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
---
include/linux/blk_types.h | 2 ++
include/linux/fs.h | 2 ++
include/linux/mm.h | 4 ++++
mm/memory.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 61 insertions(+)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 0edb65d..7b7ac9c 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -160,6 +160,7 @@ enum rq_flag_bits {
__REQ_FLUSH_SEQ, /* request for flush sequence */
__REQ_IO_STAT, /* account I/O stat */
__REQ_MIXED_MERGE, /* merge of different types, fail separately */
+ __REQ_KERNEL, /* direct IO to kernel pages */
__REQ_NR_BITS, /* stops here */
};
@@ -201,5 +202,6 @@ enum rq_flag_bits {
#define REQ_IO_STAT (1 << __REQ_IO_STAT)
#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
#define REQ_SECURE (1 << __REQ_SECURE)
+#define REQ_KERNEL (1 << __REQ_KERNEL)
#endif /* __LINUX_BLK_TYPES_H */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 006aa85..c2a4554 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -165,6 +165,8 @@ struct inodes_stat_t {
#define READ 0
#define WRITE RW_MASK
#define READA RWA_MASK
+#define KERNEL_READ (READ|REQ_KERNEL)
+#define KERNEL_WRITE (WRITE|REQ_KERNEL)
#define READ_SYNC (READ | REQ_SYNC)
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b3d4cd9..bbb3167 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1019,6 +1019,10 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
struct page **pages, struct vm_area_struct **vmas);
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages);
+struct kvec;
+int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
+ struct page **pages);
+int get_kernel_page(unsigned long start, int write, struct page **pages);
struct page *get_dump_page(unsigned long addr);
extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
diff --git a/mm/memory.c b/mm/memory.c
index 6322d36..c8153f5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1843,6 +1843,59 @@ next_page:
EXPORT_SYMBOL(__get_user_pages);
/*
+ * get_kernel_pages() - pin kernel pages in memory
+ * @kiov: An array of struct kvec structures
+ * @nr_segs: number of segments to pin
+ * @write: pinning for read/write, currently ignored
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_segs long.
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno. Each page returned must be released
+ * with a put_page() call when it is finished with.
+ */
+int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write,
+ struct page **pages)
+{
+ int seg;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE))
+ return seg;
+
+ /* virt_to_page sanity checks the PFN */
+ pages[seg] = virt_to_page(kiov[seg].iov_base);
+ page_cache_get(pages[seg]);
+ }
+
+ return seg;
+}
+EXPORT_SYMBOL_GPL(get_kernel_pages);
+
+/*
+ * get_kernel_page() - pin a kernel page in memory
+ * @start: starting kernel address
+ * @write: pinning for read/write, currently ignored
+ * @pages: array that receives pointer to the page pinned.
+ * Must be at least nr_segs long.
+ *
+ * Returns 1 if page is pinned. If the page was not pinned, returns
+ * -errno. The page returned must be released with a put_page() call
+ * when it is finished with.
+ */
+int get_kernel_page(unsigned long start, int write, struct page **pages)
+{
+ const struct kvec kiov = {
+ .iov_base = (void *)start,
+ .iov_len = PAGE_SIZE
+ };
+
+ return get_kernel_pages(&kiov, 1, write, pages);
+}
+EXPORT_SYMBOL_GPL(get_kernel_page);
+
+/*
* fixup_user_fault() - manually resolve a user page fault
* @tsk: the task_struct to use for page fault accounting, or
* NULL if faults are not to be recorded.
--
1.7.9.2
--
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* [PATCH 07/12] mm: Add support for direct_IO to highmem pages
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
The patch "mm: Add support for a filesystem to activate swap files and
use direct_IO for writing swap pages" added support for using direct_IO
to write swap pages but it is insufficient for highmem pages.
To support highmem pages, this patch kmaps() the page before calling the
direct_IO() handler. As direct_IO deals with virtual addresses an
additional helper is necessary for get_kernel_pages() to lookup the
struct page for a kmap virtual address.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
include/linux/highmem.h | 7 +++++++
mm/highmem.c | 12 ++++++++++++
mm/memory.c | 3 +--
mm/page_io.c | 3 ++-
4 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 774fa47..ef788b5 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -39,10 +39,17 @@ extern unsigned long totalhigh_pages;
void kmap_flush_unused(void);
+struct page *kmap_to_page(void *addr);
+
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
+static inline struct page *kmap_to_page(void *addr)
+{
+ return virt_to_page(addr);
+}
+
#define totalhigh_pages 0UL
#ifndef ARCH_HAS_KMAP
diff --git a/mm/highmem.c b/mm/highmem.c
index 57d82c6..d517cd1 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -94,6 +94,18 @@ static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
#endif
+struct page *kmap_to_page(void *vaddr)
+{
+ unsigned long addr = (unsigned long)vaddr;
+
+ if (addr >= PKMAP_ADDR(0) && addr <= PKMAP_ADDR(LAST_PKMAP)) {
+ int i = (addr - PKMAP_ADDR(0)) >> PAGE_SHIFT;
+ return pte_page(pkmap_page_table[i]);
+ }
+
+ return virt_to_page(addr);
+}
+
static void flush_all_zero_pkmaps(void)
{
int i;
diff --git a/mm/memory.c b/mm/memory.c
index c8153f5..94f916e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1864,8 +1864,7 @@ int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write,
if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE))
return seg;
- /* virt_to_page sanity checks the PFN */
- pages[seg] = virt_to_page(kiov[seg].iov_base);
+ pages[seg] = kmap_to_page(kiov[seg].iov_base);
page_cache_get(pages[seg]);
}
diff --git a/mm/page_io.c b/mm/page_io.c
index 4a37962..78eee32 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -205,7 +205,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
struct file *swap_file = sis->swap_file;
struct address_space *mapping = swap_file->f_mapping;
struct iovec iov = {
- .iov_base = page_address(page),
+ .iov_base = kmap(page),
.iov_len = PAGE_SIZE,
};
@@ -218,6 +218,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
&kiocb, &iov,
kiocb.ki_pos, 1);
+ kunmap(page);
if (ret == PAGE_SIZE) {
count_vm_event(PSWPOUT);
ret = 0;
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 08/12] nfs: teach the NFS client how to treat PG_swapcache pages
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
Replace all relevant occurences of page->index and page->mapping in
the NFS client with the new page_file_index() and page_file_mapping()
functions.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
fs/nfs/file.c | 6 +++---
fs/nfs/internal.h | 7 ++++---
fs/nfs/pagelist.c | 2 +-
fs/nfs/read.c | 6 +++---
fs/nfs/write.c | 38 +++++++++++++++++++-------------------
5 files changed, 30 insertions(+), 29 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index a6708e6b..406caac 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -442,7 +442,7 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset)
if (offset != 0)
return;
/* Cancel any unstarted writes on this page */
- nfs_wb_page_cancel(page->mapping->host, page);
+ nfs_wb_page_cancel(page_file_mapping(page)->host, page);
nfs_fscache_invalidate_page(page, page->mapping->host);
}
@@ -484,7 +484,7 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
*/
static int nfs_launder_page(struct page *page)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_inode *nfsi = NFS_I(inode);
dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
@@ -533,7 +533,7 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page);
lock_page(page);
- mapping = page->mapping;
+ mapping = page_file_mapping(page);
if (mapping != dentry->d_inode->i_mapping)
goto out_unlock;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 18f99ef..43ea79a 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -463,13 +463,14 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
static inline
unsigned int nfs_page_length(struct page *page)
{
- loff_t i_size = i_size_read(page->mapping->host);
+ loff_t i_size = i_size_read(page_file_mapping(page)->host);
if (i_size > 0) {
+ pgoff_t page_index = page_file_index(page);
pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
- if (page->index < end_index)
+ if (page_index < end_index)
return PAGE_CACHE_SIZE;
- if (page->index == end_index)
+ if (page_index == end_index)
return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
}
return 0;
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index aed913c..9ef8b3c 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -117,7 +117,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
* long write-back delay. This will be adjusted in
* update_nfs_request below if the region is not locked. */
req->wb_page = page;
- req->wb_index = page->index;
+ req->wb_index = page_file_index(page);
page_cache_get(page);
req->wb_offset = offset;
req->wb_pgbase = offset;
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 86ced78..c5b83ce 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -532,11 +532,11 @@ static const struct rpc_call_ops nfs_read_common_ops = {
int nfs_readpage(struct file *file, struct page *page)
{
struct nfs_open_context *ctx;
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
int error;
dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
- page, PAGE_CACHE_SIZE, page->index);
+ page, PAGE_CACHE_SIZE, page_file_index(page));
nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
nfs_add_stats(inode, NFSIOS_READPAGES, 1);
@@ -590,7 +590,7 @@ static int
readpage_async_filler(void *data, struct page *page)
{
struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *new;
unsigned int len;
int error;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index ee929e5..f6a8ebc 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -153,7 +153,7 @@ static struct nfs_page *nfs_page_find_request_locked(struct page *page)
static struct nfs_page *nfs_page_find_request(struct page *page)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *req = NULL;
spin_lock(&inode->i_lock);
@@ -165,16 +165,16 @@ static struct nfs_page *nfs_page_find_request(struct page *page)
/* Adjust the file length if we're writing beyond the end */
static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
loff_t end, i_size;
pgoff_t end_index;
spin_lock(&inode->i_lock);
i_size = i_size_read(inode);
end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
- if (i_size > 0 && page->index < end_index)
+ if (i_size > 0 && page_file_index(page) < end_index)
goto out;
- end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
+ end = page_file_offset(page) + ((loff_t)offset+count);
if (i_size >= end)
goto out;
i_size_write(inode, end);
@@ -187,7 +187,7 @@ out:
static void nfs_set_pageerror(struct page *page)
{
SetPageError(page);
- nfs_zap_mapping(page->mapping->host, page->mapping);
+ nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
}
/* We can set the PG_uptodate flag if we see that a write request
@@ -228,7 +228,7 @@ static int nfs_set_page_writeback(struct page *page)
int ret = test_set_page_writeback(page);
if (!ret) {
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_server *nfss = NFS_SERVER(inode);
if (atomic_long_inc_return(&nfss->writeback) >
@@ -242,7 +242,7 @@ static int nfs_set_page_writeback(struct page *page)
static void nfs_end_page_writeback(struct page *page)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_server *nfss = NFS_SERVER(inode);
end_page_writeback(page);
@@ -252,7 +252,7 @@ static void nfs_end_page_writeback(struct page *page)
static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *req;
int ret;
@@ -313,13 +313,13 @@ out:
static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
int ret;
nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
- nfs_pageio_cond_complete(pgio, page->index);
+ nfs_pageio_cond_complete(pgio, page_file_index(page));
ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
if (ret == -EAGAIN) {
redirty_page_for_writepage(wbc, page);
@@ -336,8 +336,8 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
struct nfs_pageio_descriptor pgio;
int err;
- nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc),
- &nfs_async_write_completion_ops);
+ nfs_pageio_init_write(&pgio, page_file_mapping(page)->host,
+ wb_priority(wbc), &nfs_async_write_completion_ops);
err = nfs_do_writepage(page, wbc, &pgio);
nfs_pageio_complete(&pgio);
if (err < 0)
@@ -470,7 +470,7 @@ nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
spin_unlock(cinfo->lock);
if (!cinfo->dreq) {
inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- inc_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
BDI_RECLAIMABLE);
__mark_inode_dirty(req->wb_context->dentry->d_inode,
I_DIRTY_DATASYNC);
@@ -537,7 +537,7 @@ static void
nfs_clear_page_commit(struct page *page)
{
dec_zone_page_state(page, NR_UNSTABLE_NFS);
- dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
+ dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE);
}
static void
@@ -788,7 +788,7 @@ out_err:
static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
struct page *page, unsigned int offset, unsigned int bytes)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *req;
req = nfs_try_to_update_request(inode, page, offset, bytes);
@@ -841,7 +841,7 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
nfs_release_request(req);
if (!do_flush)
return 0;
- status = nfs_wb_page(page->mapping->host, page);
+ status = nfs_wb_page(page_file_mapping(page)->host, page);
} while (status == 0);
return status;
}
@@ -871,7 +871,7 @@ int nfs_updatepage(struct file *file, struct page *page,
unsigned int offset, unsigned int count)
{
struct nfs_open_context *ctx = nfs_file_open_context(file);
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
int status = 0;
nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
@@ -879,7 +879,7 @@ int nfs_updatepage(struct file *file, struct page *page,
dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n",
file->f_path.dentry->d_parent->d_name.name,
file->f_path.dentry->d_name.name, count,
- (long long)(page_offset(page) + offset));
+ (long long)(page_file_offset(page) + offset));
/* If we're not using byte range locks, and we know the page
* is up to date, it may be more efficient to extend the write
@@ -1475,7 +1475,7 @@ void nfs_retry_commit(struct list_head *page_list,
nfs_mark_request_commit(req, lseg, cinfo);
if (!cinfo->dreq) {
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
- dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ dec_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
BDI_RECLAIMABLE);
}
nfs_unlock_and_release_request(req);
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 09/12] nfs: disable data cache revalidation for swapfiles
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
The VM does not like PG_private set on PG_swapcache pages. As suggested
by Trond in http://lkml.org/lkml/2006/8/25/348, this patch disables
NFS data cache revalidation on swap files. as it does not make
sense to have other clients change the file while it is being used as
swap. This avoids setting PG_private on swap pages, since there ought
to be no further races with invalidate_inode_pages2() to deal with.
Since we cannot set PG_private we cannot use page->private which
is already used by PG_swapcache pages to store the nfs_page. Thus
augment the new nfs_page_find_request logic.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
fs/nfs/inode.c | 4 ++++
fs/nfs/write.c | 49 +++++++++++++++++++++++++++++++++++--------------
2 files changed, 39 insertions(+), 14 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index edecd05..90810a4 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -883,6 +883,10 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
struct nfs_inode *nfsi = NFS_I(inode);
int ret = 0;
+ /* swapfiles are not supposed to be shared. */
+ if (IS_SWAPFILE(inode))
+ goto out;
+
if (nfs_mapping_need_revalidate_inode(inode)) {
ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
if (ret < 0)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f6a8ebc..947e1e6 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -139,15 +139,28 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
}
-static struct nfs_page *nfs_page_find_request_locked(struct page *page)
+static struct nfs_page *
+nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page)
{
struct nfs_page *req = NULL;
- if (PagePrivate(page)) {
+ if (PagePrivate(page))
req = (struct nfs_page *)page_private(page);
- if (req != NULL)
- kref_get(&req->wb_kref);
+ else if (unlikely(PageSwapCache(page))) {
+ struct nfs_page *freq, *t;
+
+ /* Linearly search the commit list for the correct req */
+ list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
+ if (freq->wb_page == page) {
+ req = freq;
+ break;
+ }
+ }
}
+
+ if (req)
+ kref_get(&req->wb_kref);
+
return req;
}
@@ -157,7 +170,7 @@ static struct nfs_page *nfs_page_find_request(struct page *page)
struct nfs_page *req = NULL;
spin_lock(&inode->i_lock);
- req = nfs_page_find_request_locked(page);
+ req = nfs_page_find_request_locked(NFS_I(inode), page);
spin_unlock(&inode->i_lock);
return req;
}
@@ -258,7 +271,7 @@ static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblo
spin_lock(&inode->i_lock);
for (;;) {
- req = nfs_page_find_request_locked(page);
+ req = nfs_page_find_request_locked(NFS_I(inode), page);
if (req == NULL)
break;
if (nfs_lock_request(req))
@@ -412,9 +425,15 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
spin_lock(&inode->i_lock);
if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE))
inode->i_version++;
- set_bit(PG_MAPPED, &req->wb_flags);
- SetPagePrivate(req->wb_page);
- set_page_private(req->wb_page, (unsigned long)req);
+ /*
+ * Swap-space should not get truncated. Hence no need to plug the race
+ * with invalidate/truncate.
+ */
+ if (likely(!PageSwapCache(req->wb_page))) {
+ set_bit(PG_MAPPED, &req->wb_flags);
+ SetPagePrivate(req->wb_page);
+ set_page_private(req->wb_page, (unsigned long)req);
+ }
nfsi->npages++;
kref_get(&req->wb_kref);
spin_unlock(&inode->i_lock);
@@ -431,9 +450,11 @@ static void nfs_inode_remove_request(struct nfs_page *req)
BUG_ON (!NFS_WBACK_BUSY(req));
spin_lock(&inode->i_lock);
- set_page_private(req->wb_page, 0);
- ClearPagePrivate(req->wb_page);
- clear_bit(PG_MAPPED, &req->wb_flags);
+ if (likely(!PageSwapCache(req->wb_page))) {
+ set_page_private(req->wb_page, 0);
+ ClearPagePrivate(req->wb_page);
+ clear_bit(PG_MAPPED, &req->wb_flags);
+ }
nfsi->npages--;
spin_unlock(&inode->i_lock);
nfs_release_request(req);
@@ -729,7 +750,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
spin_lock(&inode->i_lock);
for (;;) {
- req = nfs_page_find_request_locked(page);
+ req = nfs_page_find_request_locked(NFS_I(inode), page);
if (req == NULL)
goto out_unlock;
@@ -1744,7 +1765,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
*/
int nfs_wb_page(struct inode *inode, struct page *page)
{
- loff_t range_start = page_offset(page);
+ loff_t range_start = page_file_offset(page);
loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 10/12] nfs: enable swap on NFS
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
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>
---
fs/nfs/Kconfig | 8 +++++
fs/nfs/direct.c | 82 ++++++++++++++++++++++++++++---------------
fs/nfs/file.c | 22 ++++++++++--
include/linux/nfs_fs.h | 4 +--
include/linux/sunrpc/xprt.h | 3 ++
net/sunrpc/Kconfig | 5 +++
net/sunrpc/clnt.c | 2 ++
net/sunrpc/sched.c | 7 ++--
net/sunrpc/xprtsock.c | 54 ++++++++++++++++++++++++++++
9 files changed, 153 insertions(+), 34 deletions(-)
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index b47452f..07f35c6 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -85,6 +85,14 @@ 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
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 9a4cbfc..0f9f264 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -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(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
+ if (uio) {
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
npages, 1, 0, pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (result < 0)
- break;
+ up_read(¤t->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;
@@ -606,7 +625,7 @@ 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;
@@ -634,12 +653,19 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
if (!pagevec)
break;
- down_read(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- npages, 0, 0, pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (result < 0)
- break;
+ if (uio) {
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
+ npages, 0, 0, pagevec, NULL);
+ up_read(¤t->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;
@@ -770,7 +796,7 @@ 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;
@@ -786,7 +812,7 @@ 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;
@@ -814,7 +840,7 @@ 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;
@@ -832,7 +858,7 @@ 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:
@@ -863,7 +889,7 @@ 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;
@@ -888,7 +914,7 @@ 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;
@@ -919,7 +945,7 @@ 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;
@@ -951,7 +977,7 @@ 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;
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 406caac..d010335 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -194,7 +194,7 @@ 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,
@@ -494,6 +494,20 @@ 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,
@@ -508,6 +522,10 @@ 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
};
/*
@@ -582,7 +600,7 @@ static 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,
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index b23cfc1..fae495a 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -477,10 +477,10 @@ 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
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 77d278d..cff40aa 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -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
diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig
index 9fe8857..03d03e3 100644
--- a/net/sunrpc/Kconfig
+++ b/net/sunrpc/Kconfig
@@ -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
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f56f045..09e71d1 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -717,6 +717,8 @@ 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 (task->tk_client->cl_xprt->swapper)
+ task->tk_flags |= RPC_TASK_SWAPPER;
/* Add to the client's list of all tasks */
spin_lock(&clnt->cl_lock);
list_add_tail(&task->tk_task, &clnt->cl_tasks);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 994cfea..83a4c43 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -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);
}
/*
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 890b03f..3d58b92 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1930,6 +1930,45 @@ 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);
@@ -1954,6 +1993,8 @@ 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);
@@ -1965,11 +2006,15 @@ static void xs_udp_setup_socket(struct work_struct *work)
container_of(work, struct sock_xprt, connect_worker.work);
struct rpc_xprt *xprt = &transport->xprt;
struct socket *sock = transport->sock;
+ unsigned long pflags = current->flags;
int status = -EIO;
if (xprt->shutdown)
goto out;
+ if (xprt->swapper)
+ current->flags |= PF_MEMALLOC;
+
/* Start by resetting any existing state */
xs_reset_transport(transport);
sock = xs_create_sock(xprt, transport,
@@ -1988,6 +2033,7 @@ static void xs_udp_setup_socket(struct work_struct *work)
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
}
/*
@@ -2078,6 +2124,8 @@ 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;
@@ -2108,11 +2156,15 @@ static void xs_tcp_setup_socket(struct work_struct *work)
container_of(work, struct sock_xprt, connect_worker.work);
struct socket *sock = transport->sock;
struct rpc_xprt *xprt = &transport->xprt;
+ unsigned long pflags = current->flags;
int status = -EIO;
if (xprt->shutdown)
goto out;
+ if (xprt->swapper)
+ current->flags |= PF_MEMALLOC;
+
if (!sock) {
clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
sock = xs_create_sock(xprt, transport,
@@ -2162,6 +2214,7 @@ static void xs_tcp_setup_socket(struct work_struct *work)
case -EINPROGRESS:
case -EALREADY:
xprt_clear_connecting(xprt);
+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
return;
case -EINVAL:
/* Happens, for instance, if the user specified a link
@@ -2174,6 +2227,7 @@ out_eagain:
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
}
/**
--
1.7.9.2
^ permalink raw reply related
* [PATCH 12/12] Avoid dereferencing bd_disk during swap_entry_free for network storage
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
Commit [b3a27d: swap: Add swap slot free callback to
block_device_operations] dereferences p->bdev->bd_disk but this is a
NULL dereference if using swap-over-NFS. This patch checks SWP_BLKDEV
on the swap_info_struct before dereferencing.
With reference to this callback, Christoph Hellwig stated "Please
just remove the callback entirely. It has no user outside the staging
tree and was added clearly against the rules for that staging tree".
This would also be my preference but there was not an obvious way of
keeping zram in staging/ happy.
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
mm/swapfile.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1d77b13..f4c802d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -549,7 +549,6 @@ static unsigned char swap_entry_free(struct swap_info_struct *p,
/* free if no reference */
if (!usage) {
- struct gendisk *disk = p->bdev->bd_disk;
if (offset < p->lowest_bit)
p->lowest_bit = offset;
if (offset > p->highest_bit)
@@ -560,9 +559,11 @@ static unsigned char swap_entry_free(struct swap_info_struct *p,
nr_swap_pages++;
p->inuse_pages--;
frontswap_invalidate_page(p->type, offset);
- if ((p->flags & SWP_BLKDEV) &&
- disk->fops->swap_slot_free_notify)
- disk->fops->swap_slot_free_notify(p->bdev, offset);
+ if (p->flags & SWP_BLKDEV) {
+ struct gendisk *disk = p->bdev->bd_disk;
+ if (disk->fops->swap_slot_free_notify)
+ disk->fops->swap_slot_free_notify(p->bdev, offset);
+ }
}
return usage;
--
1.7.9.2
--
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^ permalink raw reply related
* [PATCH 11/12] nfs: Prevent page allocator recursions with swap over NFS.
From: Mel Gorman @ 2012-06-29 13:33 UTC (permalink / raw)
To: Andrew Morton
Cc: Linux-MM, Linux-Netdev, Linux-NFS, LKML, David Miller,
Trond Myklebust, Neil Brown, Christoph Hellwig, Peter Zijlstra,
Mike Christie, Eric B Munson, Sebastian Andrzej Siewior,
Mel Gorman
In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de>
GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate
IO, just not of any filesystem data.
The problem is that previously NOFS was correct because that avoids
recursion into the NFS code. With swap-over-NFS, it is no longer
correct as swap IO can lead to this recursion.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
---
fs/nfs/pagelist.c | 2 +-
fs/nfs/write.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 9ef8b3c..7de1646 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -70,7 +70,7 @@ void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
static inline struct nfs_page *
nfs_page_alloc(void)
{
- struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
+ struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
if (p)
INIT_LIST_HEAD(&p->wb_list);
return p;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 947e1e6..0f7fdb7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -52,7 +52,7 @@ static mempool_t *nfs_commit_mempool;
struct nfs_commit_data *nfs_commitdata_alloc(void)
{
- struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
+ struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
if (p) {
memset(p, 0, sizeof(*p));
@@ -70,7 +70,7 @@ EXPORT_SYMBOL_GPL(nfs_commit_free);
struct nfs_write_header *nfs_writehdr_alloc(void)
{
- struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
+ struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
if (p) {
struct nfs_pgio_header *hdr = &p->header;
--
1.7.9.2
^ permalink raw reply related
* Re: [PATCH net-next 1/2] r8169: support RTL8106E
From: Francois Romieu @ 2012-06-29 13:50 UTC (permalink / raw)
To: Hayes Wang; +Cc: netdev, linux-kernel
In-Reply-To: <1340966060-2749-1-git-send-email-hayeswang@realtek.com>
Hayes Wang <hayeswang@realtek.com> :
[...]
> Support the new chip RTL8106E.
I'll give it a try this week end.
Thanks.
--
Ueimor
^ permalink raw reply
* Re: [PATCH net-next 2/2] r8169: support RTL8168G
From: Francois Romieu @ 2012-06-29 13:51 UTC (permalink / raw)
To: Hayes Wang; +Cc: netdev, linux-kernel
In-Reply-To: <1340966060-2749-2-git-send-email-hayeswang@realtek.com>
Hayes Wang <hayeswang@realtek.com> :
[...]
> @@ -264,6 +267,11 @@ static const struct {
> [RTL_GIGA_MAC_VER_39] =
> _R("RTL8106e", RTL_TD_1, FIRMWARE_8106E_1,
> JUMBO_1K, true),
> + [RTL_GIGA_MAC_VER_40] =
> + _R("RTL8168g/8111g", RTL_TD_1, FIRMWARE_8168G_1,
> + JUMBO_9K, false),
> + [RTL_GIGA_MAC_VER_41] =
> + _R("RTL8168g/8111g", RTL_TD_1, NULL, JUMBO_9K, false),
You may explicitely state that jumbo operation requires no special action
by completing rtl_init_jumbo_ops.
(no checksuming with jumbo, sigh)
[...]
> static void rtl_lock_work(struct rtl8169_private *tp)
> {
> @@ -919,6 +936,99 @@ static int r8168dp_check_dash(struct rtl8169_private *tp)
> return (ocp_read(tp, 0x0f, reg) & 0x00008000) ? 1 : 0;
> }
>
> +static void r8168_phy_ocp_write(void __iomem *ioaddr, u32 reg, u32 data)
> +{
> + int i;
> +
> + if (reg & 0xffff0001)
> + BUG();
The patch adds a lot of BUG(). BUG is terrible from a system or end user
viewpoint.
Were they only a devel helper or are they still supposed to be of use
in the future ? If the latter applies, why ?
[...]
> +static u16 r8168_phy_ocp_read(void __iomem *ioaddr, u32 reg)
> +{
> + int i;
> + u32 data;
> +
> + if (reg & 0xffff0001)
> + BUG();
> +
> + RTL_W32(GPHY_OCP, (reg << 15));
You can save on parenthesis here.
[...]
> +static void r8168g_mdio_write(void __iomem *ioaddr, int reg_addr, int value)
> +{
> + if (reg_addr == 0x1f)
> + return;
> +
> + r8168_phy_ocp_write(ioaddr, 0xa400 + reg_addr * 2, value);
> +}
> +
> +static int r8168g_mdio_read(void __iomem *ioaddr, int reg_addr)
> +{
> + return r8168_phy_ocp_read(ioaddr, 0xa400 + reg_addr * 2);
> +}
#define XYZ_{BASE/OFFSET} 0xa400 ?
[...]
> @@ -2241,6 +2355,92 @@ static void rtl_phy_write_fw(struct rtl8169_private *tp, struct rtl_fw *rtl_fw)
> }
> }
>
> +static void rtl_ocp_write_fw(struct rtl8169_private *tp, struct rtl_fw *rtl_fw)
> +{
> + struct rtl_fw_phy_action *pa = &rtl_fw->phy_action;
> + void __iomem *ioaddr = tp->mmio_addr;
> + u32 predata, count;
> + u32 base_addr;
> + size_t index;
> +
> + predata = count = 0;
> + base_addr = 0xa400;
> +
> + for (index = 0; index < pa->size; ) {
> + u32 action = le32_to_cpu(pa->code[index]);
> + u32 data = action & 0x0000ffff;
> + u32 regno = (action & 0x0fff0000) >> 16;
> +
> + if (!action)
> + break;
> +
> + switch(action & 0xf0000000) {
> + case PHY_READ:
> + predata = r8168_phy_ocp_read(ioaddr,
> + base_addr + (regno -16) * 2);
> + count++;
> + index++;
> + break;
[duplicated code removed]
> + case PHY_WRITE:
> + if (regno == 0x1f)
> + base_addr = data << 4;
> + else
> + r8168_phy_ocp_write(ioaddr,
> + base_addr + (regno - 0x10) * 2,
> + data);
> + index++;
> + break;
[duplicated code removed]
> + case PHY_WRITE_PREVIOUS:
> + r8168_phy_ocp_write(ioaddr, base_addr + (regno -16) * 2,
> + predata);
> + index++;
> + break;
I can't believe that the hardware people have designed something which
needs a different firmware write method, especially as it copies at lot
of code.
How did you come to the conclusion that it was not possible to hide this
stuff behind r8168g_mdio_{read / write} ?
I would not mind replacing the PHY_{READ/WRITE/WRITE_PREVIOUS} case with
chipset specific {READ/WRITE/WRITE_PREVIOUS} methods as long as the
semantic looks the same but going through a different (*write_fw) does not
trivially seem to be the best abstraction.
[...]
> @@ -3221,6 +3421,56 @@ static void rtl8411_hw_phy_config(struct rtl8169_private *tp)
> rtl_writephy(tp, 0x1f, 0x0000);
> }
>
> +static void rtl8168g_1_hw_phy_config(struct rtl8169_private *tp)
> +{
> + void __iomem *ioaddr = tp->mmio_addr;
> + u32 mac_ocp_addr, i;
> + static const u16 mac_ocp_patch[] = {
> + 0xE008, 0xE01B, 0xE01D, 0xE01F,
> + 0xE021, 0xE023, 0xE025, 0xE027,
> + 0x49D2 ,0xF10D, 0x766C, 0x49E2,
> + 0xF00A, 0x1EC0, 0x8EE1, 0xC60A,
> + 0x77C0, 0x4870, 0x9FC0, 0x1EA0,
> + 0xC707, 0x8EE1, 0x9D6C, 0xC603,
> + 0xBE00, 0xB416, 0x0076, 0xE86C,
> + 0xC602, 0xBE00, 0x0000, 0xC602,
> + 0xBE00, 0x0000, 0xC602, 0xBE00,
> + 0x0000, 0xC602, 0xBE00, 0x0000,
> + 0xC602, 0xBE00, 0x0000, 0xC602,
> + 0xBE00, 0x0000, 0xC602, 0xBE00,
> + 0x0000, 0x0000, 0x0000, 0x0000
Please s/\(.*\)/\L\1/
> + };
> +
> + /* patch code for GPHY reset */
> + mac_ocp_addr = 0xf800;
> + for (i = 0; mac_ocp_addr < 0xf868; i++) {
> + r8168_mac_ocp_write(ioaddr, mac_ocp_addr, mac_ocp_patch[i]);
> + mac_ocp_addr += 2;
> + }
for (i = 0; i < ARRAY_SIZE(mac_ocp_patch); i++)
r8168_mac_ocp_write(ioaddr, 0xf800 + 2*i, mac_ocp_patch[i]);
The array must be correctly sized anyway. :o)
You may save a bit on the 'mac_ocp_patch' identifier and replace 0xf800 with
a #define.
> + r8168_mac_ocp_write(ioaddr, 0xfc26, 0x8000);
> + r8168_mac_ocp_write(ioaddr, 0xfc28, 0x0075);
> +
> + rtl_apply_firmware(tp);
> +
> + if (r8168_phy_ocp_read(ioaddr, 0xa460) & 0x0100)
> + rtl_w1w0_phy_ocp(ioaddr, 0xbcc4, 0x0000, 0x8000);
> + else
> + rtl_w1w0_phy_ocp(ioaddr, 0xbcc4, 0x8000, 0x0000);
> +
> + if (r8168_phy_ocp_read(ioaddr, 0xa466) & 0x0100)
> + rtl_w1w0_phy_ocp(ioaddr, 0xc41a, 0x0002, 0x0000);
> + else
> + rtl_w1w0_phy_ocp(ioaddr, 0xbcc4, 0x0000, 0x0002);
> +
> + rtl_w1w0_phy_ocp(ioaddr, 0xa442, 0x000c, 0x0000);
> + rtl_w1w0_phy_ocp(ioaddr, 0xa4b2, 0x0004, 0x0000);
> +
> + r8168_phy_ocp_write(ioaddr, 0xa436, 0x8012);
> + rtl_w1w0_phy_ocp(ioaddr, 0xa438, 0x8000, 0x0000);
> +
> + rtl_w1w0_phy_ocp(ioaddr, 0xc422, 0x4000, 0x2000);
> +}
Is there any chance for this part to be a bit more literate ?
[...]
> @@ -4921,6 +5193,28 @@ static void rtl_hw_start_8411(struct rtl8169_private *tp)
> ERIAR_EXGMAC);
> }
>
> +static void rtl_hw_start_8168g_1(struct rtl8169_private *tp)
> +{
> + void __iomem *ioaddr = tp->mmio_addr;
> + struct pci_dev *pdev = tp->pci_dev;
> +
> + rtl_eri_write(ioaddr, 0xc8, ERIAR_MASK_0101, 0x080002, ERIAR_EXGMAC);
> + rtl_eri_write(ioaddr, 0xcc, ERIAR_MASK_0001, 0x38, ERIAR_EXGMAC);
> + rtl_eri_write(ioaddr, 0xd0, ERIAR_MASK_0001, 0x48, ERIAR_EXGMAC);
> + rtl_eri_write(ioaddr, 0xe8, ERIAR_MASK_1111, 0x00100006, ERIAR_EXGMAC);
> + rtl_csi_access_enable_1(tp);
> + rtl_tx_performance_tweak(pdev, 0x5 << MAX_READ_REQUEST_SHIFT);
> + rtl_w1w0_eri(ioaddr, 0xdc, ERIAR_MASK_0001, 0x00, 0x01, ERIAR_EXGMAC);
> + rtl_w1w0_eri(ioaddr, 0xdc, ERIAR_MASK_0001, 0x01, 0x00, ERIAR_EXGMAC);
> + RTL_W8(ChipCmd, CmdTxEnb | CmdRxEnb);
> + RTL_W32(MISC, RTL_R32(MISC) & ~RXDV_GATED_EN);
> + RTL_W8(MaxTxPacketSize, EarlySize);
> + rtl_eri_write(ioaddr, 0xc0, ERIAR_MASK_0011, 0x0000, ERIAR_EXGMAC);
> + rtl_eri_write(ioaddr, 0xb8, ERIAR_MASK_0011, 0x0000, ERIAR_EXGMAC);
> + RTL_W8(EEE_LED, RTL_R8(EEE_LED) & ~0x07);
> + rtl_w1w0_eri(ioaddr, 0x2fc, ERIAR_MASK_0001, 0x01, 0x02, ERIAR_EXGMAC);
> +}
(ok, now it can be compared with similar functions)
[...]
> @@ -6491,6 +6790,47 @@ static unsigned rtl_try_msi(struct rtl8169_private *tp,
> return msi;
> }
>
> +static void __devinit rtl_hw_init_8168g(struct rtl8169_private *tp)
> +{
> + void __iomem *ioaddr = tp->mmio_addr;
> + u32 tmp_data;
> +
> + RTL_W32(MISC, RTL_R32(MISC) | RXDV_GATED_EN);
> + while (!(RTL_R32(TxConfig) & TXCFG_EMPTY))
> + udelay(100);
> +
> + while ((RTL_R8(MCU) & (TX_EMPTY | RX_EMPTY)) != (TX_EMPTY | RX_EMPTY))
> + udelay(100);
#define RXTX_EMPTY (TX_EMPTY | RX_EMPTY) ?
> +
> + RTL_W8(ChipCmd, RTL_R8(ChipCmd) & ~(CmdTxEnb | CmdRxEnb));
> + msleep(1);
> + RTL_W8(MCU, RTL_R8(MCU) & ~NOW_IS_OOB);
> +
> + tmp_data = r8168_mac_ocp_read(ioaddr, 0xe8de);
> + tmp_data &= ~(1 << 14);
> + r8168_mac_ocp_write(ioaddr, 0xe8de, tmp_data);
> + while (!(RTL_R8(MCU) & LINK_LIST_RDY))
> + udelay(100);
> +
> + tmp_data = r8168_mac_ocp_read(ioaddr, 0xe8de);
Same 0xe8de offset used twice. #define ?
> + tmp_data |= (1 << 15);
> + r8168_mac_ocp_write(ioaddr, 0xe8de, tmp_data);
> + while (!(RTL_R8(MCU) & LINK_LIST_RDY))
> + udelay(100);
> +}
> +
> +static void __devinit rtl_hw_initialize(struct rtl8169_private *tp)
> +{
> + switch (tp->mac_version) {
> + case RTL_GIGA_MAC_VER_40:
> + case RTL_GIGA_MAC_VER_41:
> + rtl_hw_init_8168g(tp);
> + break;
> + default:
> + break;
> + }
> +}
Why doesn't it belong to hw_start ?
Is it completely unneeded if the device requires a rtl8169_hw_reset,
resumes or such ?
Thanks.
--
Ueimor
^ permalink raw reply
* [RFC] [TCP 0/3] Receive from socket into bio without copying
From: Andreas Gruenbacher @ 2012-06-29 14:53 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: Herbert Xu, David S. Miller
Hello,
I'm (still) trying to pass data from the network to the block layer without
copying. The block layer needs blocks to be contiguous in memory, and may have
some alignment restrictions as well. A lot of modern network hardware will
receive large packets into separate buffers, so individual large packets will
end up in contiguous, aligned buffers. I would like to make use of that, but
tcp currently doesn't allow me to control what ends up in which packets.
This patch series introduces a new flag for indicating to tcp when it should
start a new segment. Using that on the sender side, I can get data over the
network with no cpu copying at all.
[My last posting on this topic from May 8 is archived here:
http://www.spinics.net/lists/netdev/msg197788.html ]
Thanks,
Andreas
Andreas Gruenbacher (3):
tcp: Add MSG_NEW_PACKET flag to indicate preferable packet boundaries
tcp: Zero-copy receive from a socket into a bio
fs: Export bio_release_pages()
fs/bio.c | 3 +-
include/linux/bio.h | 1 +
include/linux/socket.h | 1 +
include/net/tcp.h | 3 +
net/ipv4/Makefile | 3 +-
net/ipv4/tcp.c | 5 +-
net/ipv4/tcp_recvbio.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 180 insertions(+), 4 deletions(-)
create mode 100644 net/ipv4/tcp_recvbio.c
--
1.7.10.2
^ permalink raw reply
* [RFC] [TCP 1/3] tcp: Add MSG_NEW_PACKET flag to indicate preferable packet boundaries
From: Andreas Gruenbacher @ 2012-06-29 14:54 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: Herbert Xu, David S. Miller
The MSG_NEW_PACKET flag indicates to sendmsg / sendpage that the message or
page should be put into a new packet even when there is still room left in the
previous packet.
In the tcp protocol, messages which are not sent immediately are queued. When
more data is sent, it will be added to the last segment in that queue until
that segment is "full" whenever possible; only then is a new segment added.
Right now, there is no way to indicate when tcp should start a new segment.
The new flag allows to control that.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
---
include/linux/socket.h | 1 +
net/ipv4/tcp.c | 5 +++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 25d6322..be166de 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -266,6 +266,7 @@ struct ucred {
#define MSG_MORE 0x8000 /* Sender will send more */
#define MSG_WAITFORONE 0x10000 /* recvmmsg(): block until 1+ packets avail */
#define MSG_SENDPAGE_NOTLAST 0x20000 /* sendpage() internal : not the last page */
+#define MSG_NEW_PACKET 0x40000 /* tcp: try to put message into a new packet */
#define MSG_EOF MSG_FIN
#define MSG_CMSG_CLOEXEC 0x40000000 /* Set close_on_exit for file
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3ba605f..148aebe 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -854,7 +854,8 @@ static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffse
int size = min_t(size_t, psize, PAGE_SIZE - offset);
bool can_coalesce;
- if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
+ if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0 ||
+ (flags & MSG_NEW_PACKET)) {
new_segment:
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
@@ -1044,7 +1045,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
copy = max - skb->len;
}
- if (copy <= 0) {
+ if (copy <= 0 || (flags & MSG_NEW_PACKET)) {
new_segment:
/* Allocate new segment. If the interface is SG,
* allocate skb fitting to single page.
--
1.7.10.2
^ permalink raw reply related
* [RFC] [TCP 2/3] tcp: Zero-copy receive from a socket into a bio
From: Andreas Gruenbacher @ 2012-06-29 14:55 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: Herbert Xu, David S. Miller
"Receive" data from a tcp socket by directly mapping sectors in the socket receive
buffers into a bio without copying. This requires that the receive buffer
contains contiguous sectors which are well-enough aligned for the block device
associated with the bio.
Any data that cannot be mapped into the bio is left in the socket receive
buffers and can be received conventionally, by copying it out of the buffers.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
---
include/net/tcp.h | 3 +
net/ipv4/Makefile | 3 +-
net/ipv4/tcp_recvbio.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 173 insertions(+), 1 deletion(-)
create mode 100644 net/ipv4/tcp_recvbio.c
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e79aa48..c4d924b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -538,6 +538,9 @@ typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
+/* tcp_recvbio.c */
+extern int tcp_recvbio(struct sock *sk, struct bio *bio, size_t size);
+
extern void tcp_initialize_rcv_mss(struct sock *sk);
extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index ff75d3b..7ee9f92 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -11,7 +11,8 @@ obj-y := route.o inetpeer.o protocol.o \
datagram.o raw.o udp.o udplite.o \
arp.o icmp.o devinet.o af_inet.o igmp.o \
fib_frontend.o fib_semantics.o fib_trie.o \
- inet_fragment.o ping.o
+ inet_fragment.o ping.o \
+ tcp_recvbio.o
obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
obj-$(CONFIG_PROC_FS) += proc.o
diff --git a/net/ipv4/tcp_recvbio.c b/net/ipv4/tcp_recvbio.c
new file mode 100644
index 0000000..4d6f833
--- /dev/null
+++ b/net/ipv4/tcp_recvbio.c
@@ -0,0 +1,168 @@
+#include <linux/module.h>
+#include <net/tcp.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+
+static int tcp_recvbio_add(struct bio *bio, struct sk_buff *skb,
+ struct bio_vec *last)
+{
+ struct request_queue *q = bio->bi_bdev->bd_disk->queue;
+ unsigned short vcnt = bio->bi_vcnt;
+ int ret;
+
+ if (vcnt == queue_max_segments(q))
+ return 0;
+ if (!blk_rq_aligned(q, last->bv_offset, last->bv_len))
+ return -EOPNOTSUPP;
+ ret = bio_add_page(bio, last->bv_page, last->bv_len, last->bv_offset);
+ if (vcnt != bio->bi_vcnt)
+ get_page(last->bv_page);
+ return ret;
+}
+
+static int tcp_recvbio_data(read_descriptor_t *rd_desc, struct sk_buff *skb,
+ unsigned int offset, size_t len)
+{
+ struct bio *bio = rd_desc->arg.data;
+ int start = skb_headlen(skb), consumed = 0, frag_len, i;
+ struct sk_buff *frag_iter;
+ struct bio_vec last = { };
+ int ret = 0;
+
+ if (offset > (int)skb->len - len)
+ return -EFAULT;
+
+ /* Do not consume more data than we need. */
+ if (len > rd_desc->count)
+ len = rd_desc->count;
+
+ /* Head of the skb */
+ frag_len = start - offset;
+ if (frag_len > 0) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ int end;
+
+ WARN_ON(start > offset + len);
+
+ end = start + skb_frag_size(frag);
+ frag_len = end - offset;
+ if (frag_len > 0) {
+ if (frag_len > len)
+ frag_len = len;
+
+ last.bv_page = skb_frag_page(frag);
+ last.bv_offset = frag->page_offset + offset - start;
+ last.bv_len = frag_len;
+ ret = tcp_recvbio_add(bio, skb, &last);
+ if (ret <= 0)
+ goto out;
+ consumed += frag_len;
+ len -= frag_len;
+ if (!len)
+ break;
+ offset += frag_len;
+ }
+ start = end;
+ }
+
+ skb_walk_frags(skb, frag_iter) {
+ int end;
+
+ WARN_ON(start > offset + len);
+
+ end = start + frag_iter->len;
+ frag_len = end - offset;
+ if (frag_len > 0) {
+ if (frag_len > len)
+ frag_len = len;
+
+ ret = tcp_recvbio_data(rd_desc, frag_iter, offset -
+ start, frag_len);
+ if (ret <= 0)
+ goto out;
+ consumed += frag_len;
+ len -= frag_len;
+ if (!len)
+ break;
+ offset += frag_len;
+ }
+ start = end;
+ }
+
+out:
+ rd_desc->written += consumed;
+ rd_desc->count -= consumed;
+ return consumed ? consumed : ret;
+}
+
+/**
+ * tcp_recvbio - zero-copy receive from a socket into a bio
+ * @sk: socket to receive from
+ * @bio: empty bio to receive into
+ * @size: number of bytes to receive
+ *
+ * Directly add page fragments from @sk's receive buffer to @bio. The page
+ * fragments are held referenced with get_page(). Release those references
+ * with bio_release_pages() when done.
+ *
+ * Returns the number of bytes received into @bio.
+ */
+int tcp_recvbio(struct sock *sk, struct bio *bio, size_t size)
+{
+ long timeo = sock_rcvtimeo(sk, 0);
+ read_descriptor_t rd_desc = {
+ .count = size,
+ .arg = { .data = bio },
+ };
+ int ret = 0;
+
+ BUG_ON(bio->bi_idx != 0);
+
+ lock_sock(sk);
+ while (rd_desc.count) {
+ read_lock(&sk->sk_callback_lock);
+ ret = tcp_read_sock(sk, &rd_desc, tcp_recvbio_data);
+ read_unlock(&sk->sk_callback_lock);
+ if (ret < 0)
+ break;
+ else if (ret > 0)
+ timeo = sock_rcvtimeo(sk, 0);
+ else {
+ if (sock_flag(sk, SOCK_DONE))
+ break;
+ if (sk->sk_err) {
+ ret = sock_error(sk);
+ break;
+ }
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ break;
+ if (sk->sk_state == TCP_CLOSE) {
+ /*
+ * This occurs when user tries to read
+ * from never connected socket.
+ */
+ if (!sock_flag(sk, SOCK_DONE))
+ ret = -ENOTCONN;
+ break;
+ }
+ if (!timeo) {
+ ret = -EAGAIN;
+ break;
+ }
+ sk_wait_data(sk, &timeo);
+ if (signal_pending(current)) {
+ ret = timeo ? sock_intr_errno(timeo) : -EAGAIN;
+ break;
+ }
+ timeo = 0;
+ }
+ }
+ release_sock(sk);
+ return rd_desc.written ? rd_desc.written : ret;
+}
+EXPORT_SYMBOL(tcp_recvbio);
--
1.7.10.2
^ permalink raw reply related
* [RFC] [TCP 3/3] fs: Export bio_release_pages()
From: Andreas Gruenbacher @ 2012-06-29 14:56 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: Herbert Xu, David S. Miller
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
---
fs/bio.c | 3 ++-
include/linux/bio.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/bio.c b/fs/bio.c
index 73922ab..90501a5 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1335,7 +1335,7 @@ void bio_set_pages_dirty(struct bio *bio)
}
}
-static void bio_release_pages(struct bio *bio)
+void bio_release_pages(struct bio *bio)
{
struct bio_vec *bvec = bio->bi_io_vec;
int i;
@@ -1347,6 +1347,7 @@ static void bio_release_pages(struct bio *bio)
put_page(page);
}
}
+EXPORT_SYMBOL(bio_release_pages);
/*
* bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 2643589..268ec49 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -246,6 +246,7 @@ extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
gfp_t, int);
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
+extern void bio_release_pages(struct bio *bio);
#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
--
1.7.10.2
^ permalink raw reply related
* Re: [RFC] [TCP 0/3] Receive from socket into bio without copying
From: Eric Dumazet @ 2012-06-29 15:08 UTC (permalink / raw)
To: Andreas Gruenbacher; +Cc: netdev, linux-kernel, Herbert Xu, David S. Miller
In-Reply-To: <1340981632.25226.2.camel@gurkel.linbit>
On Fri, 2012-06-29 at 16:53 +0200, Andreas Gruenbacher wrote:
> Hello,
>
> I'm (still) trying to pass data from the network to the block layer without
> copying. The block layer needs blocks to be contiguous in memory, and may have
> some alignment restrictions as well. A lot of modern network hardware will
> receive large packets into separate buffers, so individual large packets will
> end up in contiguous, aligned buffers. I would like to make use of that, but
> tcp currently doesn't allow me to control what ends up in which packets.
>
> This patch series introduces a new flag for indicating to tcp when it should
> start a new segment. Using that on the sender side, I can get data over the
> network with no cpu copying at all.
>
> [My last posting on this topic from May 8 is archived here:
> http://www.spinics.net/lists/netdev/msg197788.html ]
>
> Thanks,
> Andreas
>
> Andreas Gruenbacher (3):
> tcp: Add MSG_NEW_PACKET flag to indicate preferable packet boundaries
> tcp: Zero-copy receive from a socket into a bio
> fs: Export bio_release_pages()
This looks like yet another zero copy, needing another couple of hundred
of lines.
Why splice infrastructure doesnt fit your needs ?
^ permalink raw reply
* [patch net-next v2 0/4] net: introduce and use IFF_LIFE_ADDR_CHANGE
From: Jiri Pirko @ 2012-06-29 15:10 UTC (permalink / raw)
To: netdev; +Cc: mst, shimoda.hiroaki, virtualization, danny.kukawka, edumazet,
davem
three drivers updated, but this can be used in many others.
v1->v2:
%s/LIFE/LIVE
Jiri Pirko (4):
net: introduce new priv_flag indicating iface capable of change mac
when running
virtio_net: use IFF_LIVE_ADDR_CHANGE priv_flag
team: use IFF_LIVE_ADDR_CHANGE priv_flag
dummy: use IFF_LIVE_ADDR_CHANGE priv_flag
drivers/net/dummy.c | 15 ++-------------
drivers/net/team/team.c | 9 +++++----
drivers/net/virtio_net.c | 11 +++++------
include/linux/if.h | 2 ++
net/ethernet/eth.c | 2 +-
5 files changed, 15 insertions(+), 24 deletions(-)
--
1.7.10.4
^ permalink raw reply
* [patch net-next v2 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
From: Jiri Pirko @ 2012-06-29 15:10 UTC (permalink / raw)
To: netdev; +Cc: mst, shimoda.hiroaki, virtualization, danny.kukawka, edumazet,
davem
In-Reply-To: <1340982608-897-1-git-send-email-jpirko@redhat.com>
Introduce IFF_LIVE_ADDR_CHANGE priv_flag and use it to disable
netif_running() check in eth_mac_addr()
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
---
include/linux/if.h | 2 ++
net/ethernet/eth.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/if.h b/include/linux/if.h
index f995c66..1ec407b 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -81,6 +81,8 @@
#define IFF_UNICAST_FLT 0x20000 /* Supports unicast filtering */
#define IFF_TEAM_PORT 0x40000 /* device used as team port */
#define IFF_SUPP_NOFCS 0x80000 /* device supports sending custom FCS */
+#define IFF_LIVE_ADDR_CHANGE 0x100000 /* device supports hardware address
+ * change when it's running */
#define IF_GET_IFACE 0x0001 /* for querying only */
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 36e5880..db6a6c1 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -283,7 +283,7 @@ int eth_mac_addr(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
- if (netif_running(dev))
+ if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
return -EBUSY;
if (!is_valid_ether_addr(addr->sa_data))
return -EADDRNOTAVAIL;
--
1.7.10.4
^ permalink raw reply related
* [patch net-next v2 2/4] virtio_net: use IFF_LIVE_ADDR_CHANGE priv_flag
From: Jiri Pirko @ 2012-06-29 15:10 UTC (permalink / raw)
To: netdev
Cc: davem, rusty, mst, virtualization, edumazet, danny.kukawka,
shimoda.hiroaki
In-Reply-To: <1340982608-897-1-git-send-email-jpirko@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
---
drivers/net/virtio_net.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 36a16d5..1db445b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -679,12 +679,11 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
{
struct virtnet_info *vi = netdev_priv(dev);
struct virtio_device *vdev = vi->vdev;
- struct sockaddr *addr = p;
+ int ret;
- if (!is_valid_ether_addr(addr->sa_data))
- return -EADDRNOTAVAIL;
- memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
- dev->addr_assign_type &= ~NET_ADDR_RANDOM;
+ ret = eth_mac_addr(dev, p);
+ if (ret)
+ return ret;
if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
@@ -1063,7 +1062,7 @@ static int virtnet_probe(struct virtio_device *vdev)
return -ENOMEM;
/* Set up network device as normal. */
- dev->priv_flags |= IFF_UNICAST_FLT;
+ dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
dev->netdev_ops = &virtnet_netdev;
dev->features = NETIF_F_HIGHDMA;
--
1.7.10.4
^ permalink raw reply related
* [patch net-next v2 3/4] team: use IFF_LIVE_ADDR_CHANGE priv_flag
From: Jiri Pirko @ 2012-06-29 15:10 UTC (permalink / raw)
To: netdev
Cc: davem, rusty, mst, virtualization, edumazet, danny.kukawka,
shimoda.hiroaki
In-Reply-To: <1340982608-897-1-git-send-email-jpirko@redhat.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
---
drivers/net/team/team.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 89853c3..9b94f53 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1188,10 +1188,11 @@ static int team_set_mac_address(struct net_device *dev, void *p)
{
struct team *team = netdev_priv(dev);
struct team_port *port;
- struct sockaddr *addr = p;
+ int err;
- dev->addr_assign_type &= ~NET_ADDR_RANDOM;
- memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+ err = eth_mac_addr(dev, p);
+ if (err)
+ return err;
rcu_read_lock();
list_for_each_entry_rcu(port, &team->port_list, list)
if (team->ops.port_change_mac)
@@ -1393,7 +1394,7 @@ static void team_setup(struct net_device *dev)
* bring us to promisc mode in case a unicast addr is added.
* Let this up to underlay drivers.
*/
- dev->priv_flags |= IFF_UNICAST_FLT;
+ dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
dev->features |= NETIF_F_LLTX;
dev->features |= NETIF_F_GRO;
--
1.7.10.4
^ permalink raw reply related
* [patch net-next v2 4/4] dummy: use IFF_LIVE_ADDR_CHANGE priv_flag
From: Jiri Pirko @ 2012-06-29 15:10 UTC (permalink / raw)
To: netdev
Cc: davem, rusty, mst, virtualization, edumazet, danny.kukawka,
shimoda.hiroaki
In-Reply-To: <1340982608-897-1-git-send-email-jpirko@redhat.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
---
drivers/net/dummy.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index bab0158..9d6a067 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -40,18 +40,6 @@
static int numdummies = 1;
-static int dummy_set_address(struct net_device *dev, void *p)
-{
- struct sockaddr *sa = p;
-
- if (!is_valid_ether_addr(sa->sa_data))
- return -EADDRNOTAVAIL;
-
- dev->addr_assign_type &= ~NET_ADDR_RANDOM;
- memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
- return 0;
-}
-
/* fake multicast ability */
static void set_multicast_list(struct net_device *dev)
{
@@ -118,7 +106,7 @@ static const struct net_device_ops dummy_netdev_ops = {
.ndo_start_xmit = dummy_xmit,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_rx_mode = set_multicast_list,
- .ndo_set_mac_address = dummy_set_address,
+ .ndo_set_mac_address = eth_mac_addr,
.ndo_get_stats64 = dummy_get_stats64,
};
@@ -134,6 +122,7 @@ static void dummy_setup(struct net_device *dev)
dev->tx_queue_len = 0;
dev->flags |= IFF_NOARP;
dev->flags &= ~IFF_MULTICAST;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_TSO;
dev->features |= NETIF_F_HW_CSUM | NETIF_F_HIGHDMA | NETIF_F_LLTX;
eth_hw_addr_random(dev);
--
1.7.10.4
^ permalink raw reply related
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