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openwrt-xburst/obsolete-buildroot/sources/openwrt/kernel/patches/130-nfsswap.patch

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diff -Nurb linux.orig/Documentation/netswap.txt linux/Documentation/netswap.txt
--- linux.orig/Documentation/netswap.txt 1969-12-31 19:00:00.000000000 -0500
+++ linux/Documentation/netswap.txt 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,51 @@
+ Swapping over network
+
+Support for this is enabled via the CONFIG_NETSWAP option, which is
+automatically enabled when enabling swap files located on NFS volumes
+(CONFIG_SWAP_VIA_NFS).
+
+When swapping to files located on a network file system like NFS or
+CODA or others or to nbd (network block device, see `nbd.txt')
+partitions there is the problem that this requires additional memory,
+besides the page which is currently swapped in or out, probably at
+least two more pages for each page in question.
+
+This means that not only there needs to be free space left in the swap
+file or the swap partition, but in addition there must be enough free
+memory left in the system to perform the swap out of pages.
+
+This is particularly painful as receiving data over the network itself
+consumes memory, and this memory is allocated from an interrupt
+context (i.e. in the interrupt handler of the network card). That
+means that on a congested network there are chances that the machine
+runs out of memory, simply because the network device's interrupt
+routines allocate memory faster that it is freed by swapping via
+network.
+
+To cope with this problem, there is a new socket option `SO_SWAPPING'
+which has to be set on the `SOL_SOCKET' level with setsockopt() (see
+setsockopt(2)). When this option is set on any network socket, then
+the system will start to drop network packets it receives on any other
+socket when the number of free pages falls below a certain threshold.
+
+This threshold initially is 4 pages less than `freepages.min' (see
+`Documentation/sysctl/vm.txt') but can be tuned using the sysctl
+interface by writing to the file `/proc/sys/net/swapping/threshold'
+
+There are two other files:
+
+`/proc/sys/net/swapping/dropped':
+ how many network packets have been dropped so far. This file is
+ writable, writing to it simply sets the counter to the given value
+ (useful for resetting the counter).
+
+`/proc/sys/net/swapping/sock_count':
+ How many network sockets have the `SO_SWAPPING' option set (read
+ only, of course).
+
+When using swap-files on NFS volumes, then the `SO_SWAPPING' option is
+set or cleared by swapon/swapoff system calls, so the user need not
+care about it.
+
+Swapping over the network is insecure unless the data would be
+encrypted, which is not the case with NFS. It is also very slow.
diff -Nurb linux.orig/Documentation/nfsswap.txt linux/Documentation/nfsswap.txt
--- linux.orig/Documentation/nfsswap.txt 1969-12-31 19:00:00.000000000 -0500
+++ linux/Documentation/nfsswap.txt 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,41 @@
+ Swapping to files on NFS volumes
+
+To do this you have to say `Y' or `M' to the CONFIG_SWAP_VIA_NFS
+configuration option. When compling support for this as a module you
+should read `Documentation/modules.txt'. For auto-loading of the
+module during the `swapon' system call you have to place a line like
+
+alias swapfile-mod nfsswap
+
+in `/etc/modules.conf' (or `/etc/conf.modules', depending on your
+setup). NFS volumes holding swapfile should be mounted with `rsize'
+and `wsize' set to something less than the size of a page, otherwise
+deadlocks caused by memory fragmentation can happen, i.e. mount the
+volume which is to hold the swapfiles with
+
+mount -t nfs -o rsize=2048,wsize=2048 NFS_SERVER_IP:/server_volume /mount_point
+
+or set the option in `/etc/fstab'. Read `Documentation/nfsroot.txt' to
+learn how to set mount options for the root file system, if your swap
+files are to be located on the root file system.
+
+Setting the `rsize' and `wsize' to anything less than PAGE_SIZE is a
+performance hit, so you probably want to have at least two volumes
+mounted, one for the swapfiles, one for the rest.
+
+You may want to read `Documentation/netswap.txt' as well.
+
+Swapfiles on NFS volumes can be treated like any other swapfile,
+i.e.
+
+dd if=/dev/zero of=/swapfiles/SWAPFILE bs=1k count=20480
+mkswap /swapfiles/SWAPFILE
+swapon /swapfiles/SWAPFILE
+
+will create a 20M swapfile and tell the system to use it. Actually,
+one could use lseek(2) to create an empty swapfile. This is different
+from swapfiles located on local harddisk.
+
+Swapping over the network is insecure unless the data would be
+encrypted, which is not the case with NFS. It is also very slow.
+
diff -Nurb linux.orig/drivers/block/blkpg.c linux/drivers/block/blkpg.c
--- linux.orig/drivers/block/blkpg.c 2003-07-04 04:11:31.000000000 -0400
+++ linux/drivers/block/blkpg.c 2004-05-31 02:18:03.000000000 -0400
@@ -34,7 +34,7 @@
#include <linux/blk.h> /* for set_device_ro() */
#include <linux/blkpg.h>
#include <linux/genhd.h>
-#include <linux/swap.h> /* for is_swap_partition() */
+#include <linux/swap.h> /* for swap_run_test() */
#include <linux/module.h> /* for EXPORT_SYMBOL */
#include <asm/uaccess.h>
@@ -114,6 +114,29 @@
return 0;
}
+/* swap_run_test() applies this hook to all swapfiles until it returns
+ * "1". If it never returns "1", the result of swap_run_test() is "0",
+ * otherwise "1".
+ */
+static int is_swap_partition_hook(unsigned int flags, struct file *swap_file,
+ void *testdata)
+{
+ kdev_t swap_dev = S_ISBLK(swap_file->f_dentry->d_inode->i_mode)
+ ? swap_file->f_dentry->d_inode->i_rdev : 0;
+ kdev_t dev = *((kdev_t *)testdata);
+
+ if (flags & SWP_USED && dev == swap_dev) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+static inline int is_swap_partition(kdev_t dev)
+{
+ return swap_run_test(is_swap_partition_hook, &dev);
+}
+
/*
* Delete a partition given by partition number
*
diff -Nurb linux.orig/fs/Config.in linux/fs/Config.in
--- linux.orig/fs/Config.in 2004-05-31 02:02:43.000000000 -0400
+++ linux/fs/Config.in 2004-05-31 02:18:03.000000000 -0400
@@ -4,6 +4,12 @@
mainmenu_option next_comment
comment 'File systems'
+if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+ tristate 'Swapping to block devices' CONFIG_BLKDEV_SWAP
+else
+ define_bool CONFIG_BLKDEV_SWAP y
+fi
+
bool 'Quota support' CONFIG_QUOTA
tristate 'Kernel automounter support' CONFIG_AUTOFS_FS
tristate 'Kernel automounter version 4 support (also supports v3)' CONFIG_AUTOFS4_FS
@@ -110,6 +116,12 @@
dep_tristate 'NFS file system support' CONFIG_NFS_FS $CONFIG_INET
dep_mbool ' Provide NFSv3 client support' CONFIG_NFS_V3 $CONFIG_NFS_FS
dep_bool ' Root file system on NFS' CONFIG_ROOT_NFS $CONFIG_NFS_FS $CONFIG_IP_PNP
+ if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+ dep_tristate ' Swapping via NFS (EXPERIMENTAL)' CONFIG_SWAP_VIA_NFS $CONFIG_NFS_FS
+ if [ "$CONFIG_SWAP_VIA_NFS" = "y" -o "$CONFIG_SWAP_VIA_NFS" = "m" ]; then
+ define_bool CONFIG_NETSWAP y
+ fi
+ fi
dep_tristate 'NFS server support' CONFIG_NFSD $CONFIG_INET
dep_mbool ' Provide NFSv3 server support' CONFIG_NFSD_V3 $CONFIG_NFSD
diff -Nurb linux.orig/fs/Makefile linux/fs/Makefile
--- linux.orig/fs/Makefile 2004-05-31 02:02:42.000000000 -0400
+++ linux/fs/Makefile 2004-05-31 02:18:03.000000000 -0400
@@ -8,7 +8,7 @@
O_TARGET := fs.o
export-objs := filesystems.o open.o dcache.o buffer.o
-mod-subdirs := nls
+mod-subdirs := nls nfs
obj-y := open.o read_write.o devices.o file_table.o buffer.o \
super.o block_dev.o char_dev.o stat.o exec.o pipe.o namei.o \
@@ -70,6 +70,7 @@
subdir-$(CONFIG_JFS_FS) += jfs
subdir-$(CONFIG_SQUASHFS) += squashfs
+obj-$(CONFIG_BLKDEV_SWAP) += blkdev_swap.o
obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o
obj-$(CONFIG_BINFMT_EM86) += binfmt_em86.o
diff -Nurb linux.orig/fs/blkdev_swap.c linux/fs/blkdev_swap.c
--- linux.orig/fs/blkdev_swap.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/fs/blkdev_swap.c 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,309 @@
+/*
+ * Swapping to partitions or files located on partitions.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/locks.h>
+#include <linux/blkdev.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/fs.h>
+
+#ifdef DEBUG_BLKDEV_SWAP
+# define dprintk(fmt...) printk(##fmt)
+#else
+# define dprintk(fmt...) do { /* */ } while (0)
+#endif
+
+#define BLKDEV_SWAP_ID "blkdev"
+#define BLKDEV_FILE_SWAP_ID "blkdev file"
+
+/*
+ * Helper function, copied here from buffer.c
+ */
+
+/*
+ * Start I/O on a page.
+ * This function expects the page to be locked and may return
+ * before I/O is complete. You then have to check page->locked
+ * and page->uptodate.
+ *
+ * brw_page() is SMP-safe, although it's being called with the
+ * kernel lock held - but the code is ready.
+ *
+ * FIXME: we need a swapper_inode->get_block function to remove
+ * some of the bmap kludges and interface ugliness here.
+ */
+int brw_page(int rw, struct page *page, kdev_t dev, int b[], int size)
+{
+ struct buffer_head *head, *bh;
+
+ if (!PageLocked(page))
+ panic("brw_page: page not locked for I/O");
+
+ if (!page->buffers)
+ create_empty_buffers(page, dev, size);
+ head = bh = page->buffers;
+
+ /* Stage 1: lock all the buffers */
+ do {
+ lock_buffer(bh);
+ bh->b_blocknr = *(b++);
+ set_bit(BH_Mapped, &bh->b_state);
+ set_buffer_async_io(bh);
+ bh = bh->b_this_page;
+ } while (bh != head);
+
+ /* Stage 2: start the IO */
+ do {
+ struct buffer_head *next = bh->b_this_page;
+ submit_bh(rw, bh);
+ bh = next;
+ } while (bh != head);
+ return 0;
+}
+
+/*
+ * We implement to methods: swapping to partitions, and swapping to files
+ * located on partitions.
+ */
+
+struct blkdev_swap_data {
+ kdev_t dev;
+};
+
+struct test_data {
+ struct file * filp;
+ kdev_t dev;
+};
+
+static int is_blkdev_swapping(unsigned int flags,
+ struct file * swapf,
+ void *data)
+{
+ struct test_data *testdata = (struct test_data *) data;
+ struct file * filp = testdata->filp;
+ kdev_t dev = testdata->dev;
+
+ /* Only check filp's that don't match the one already opened
+ * for us by sys_swapon(). Otherwise, we will always flag a
+ * busy swap file.
+ */
+
+ if (swapf != filp) {
+ if (dev == swapf->f_dentry->d_inode->i_rdev)
+ return 1;
+ }
+ return 0;
+}
+
+static int blkdev_swap_open(struct file * filp, void **dptr)
+{
+ int swapfilesize;
+ kdev_t dev;
+ struct blkdev_swap_data *data;
+ int error;
+ struct test_data testdata;
+
+ MOD_INC_USE_COUNT;
+
+ if (!S_ISBLK(filp->f_dentry->d_inode->i_mode)) {
+ dprintk(__FUNCTION__": can't handle this swap file: %s\n",
+ swapf->d_name.name);
+ error = 0; /* not for us */
+ goto bad_swap;
+ }
+
+ dev = filp->f_dentry->d_inode->i_rdev;
+ set_blocksize(dev, PAGE_SIZE);
+ error = -ENODEV;
+ if (!dev ||
+ (blk_size[MAJOR(dev)] && !blk_size[MAJOR(dev)][MINOR(dev)])) {
+ printk("blkdev_swap_open: blkdev weirdness for %s\n",
+ filp->f_dentry->d_name.name);
+ goto bad_swap;
+ }
+
+ /* Check to make sure that we aren't already swapping. */
+ error = -EBUSY;
+ testdata.filp = filp;
+ testdata.dev = dev;
+ if (swap_run_test(is_blkdev_swapping, &testdata)) {
+ printk("blkdev_swap_open: already swapping to %s\n",
+ filp->f_dentry->d_name.name);
+ goto bad_swap;
+ }
+
+ swapfilesize = 0;
+ if (blk_size[MAJOR(dev)])
+ swapfilesize = blk_size[MAJOR(dev)][MINOR(dev)]
+ >> (PAGE_SHIFT - 10);
+
+ if ((data = kmalloc(sizeof(*data), GFP_KERNEL)) == NULL) {
+ printk("blkdev_swap_open: can't allocate data for %s\n",
+ filp->f_dentry->d_name.name);
+ error = -ENOMEM;
+ goto bad_swap;
+ }
+ data->dev = dev;
+ *dptr = data;
+
+ dprintk("blkdev_swap_open: returning %d\n", swapfilesize);
+ return swapfilesize;
+
+ bad_swap:
+ MOD_DEC_USE_COUNT;
+ return error; /* this swap thing is not for us */
+}
+
+static int blkdev_swap_release(struct file * filp, void *data)
+{
+ dprintk("blkdev_swap_release: releasing swap device %s\n",
+ filp->f_dentry->d_name.name);
+ kfree(data);
+ MOD_DEC_USE_COUNT;
+ return 0;
+}
+
+static int blkdev_rw_page(int rw, struct page *page, unsigned long offset,
+ void *ptr)
+{
+ struct blkdev_swap_data *data = (struct blkdev_swap_data *)ptr;
+ brw_page(rw, page, data->dev, (int *)&offset, PAGE_SIZE);
+ return 1;
+}
+
+static struct swap_ops blkdev_swap_ops = {
+ blkdev_swap_open,
+ blkdev_swap_release,
+ blkdev_rw_page
+};
+
+struct blkdevfile_swap_data {
+ struct inode *swapf;
+};
+
+static int is_blkdevfile_swapping(unsigned int flags,
+ struct file * swapf,
+ void * data)
+{
+ struct file * filp = (struct file *) data;
+
+ /* Only check filp's that don't match the one already opened
+ * for us by sys_swapon(). Otherwise, we will always flag a
+ * busy swap file.
+ */
+
+ if (swapf != filp) {
+ if (filp->f_dentry->d_inode == swapf->f_dentry->d_inode)
+ return 1;
+ }
+ return 0;
+}
+
+static int blkdevfile_swap_open(struct file *swapf, void **dptr)
+{
+ int error = 0;
+ int swapfilesize;
+ struct blkdevfile_swap_data *data;
+
+ MOD_INC_USE_COUNT;
+
+ /* first check whether this is a regular file located on a local
+ * hard disk
+ */
+ if (!S_ISREG(swapf->f_dentry->d_inode->i_mode)) {
+ dprintk("blkdevfile_swap_open: "
+ "can't handle this swap file: %s\n",
+ swapf->d_name.name);
+ error = 0; /* not for us */
+ goto bad_swap;
+ }
+ if (!swapf->f_dentry->d_inode->i_mapping->a_ops->bmap) {
+ dprintk("blkdevfile_swap_open: no bmap for file: %s\n",
+ swapf->d_name.name);
+ error = 0; /* not for us */
+ goto bad_swap;
+ }
+
+ if (swap_run_test(is_blkdevfile_swapping, swapf)) {
+ dprintk("blkdevfile_swap_open: already swapping to %s\n",
+ swapf->d_name.name);
+ error = -EBUSY;
+ goto bad_swap;
+ }
+ swapfilesize = swapf->f_dentry->d_inode->i_size >> PAGE_SHIFT;
+ if ((data = kmalloc(sizeof(*data), GFP_KERNEL)) == NULL) {
+ error = -ENOMEM;
+ goto bad_swap;
+ }
+ data->swapf = swapf->f_dentry->d_inode;
+ *dptr = data;
+ return swapfilesize;
+
+ bad_swap:
+ MOD_DEC_USE_COUNT;
+ return error;
+}
+
+static int blkdevfile_swap_release(struct file *swapf, void *data)
+{
+ kfree(data);
+ MOD_DEC_USE_COUNT;
+ return 0;
+}
+
+static int blkdevfile_rw_page(int rw, struct page *page, unsigned long offset,
+ void *ptr)
+{
+ struct blkdevfile_swap_data *data = (struct blkdevfile_swap_data *)ptr;
+ struct inode * swapf = data->swapf;
+ int i, j;
+ unsigned int block = offset
+ << (PAGE_SHIFT - swapf->i_sb->s_blocksize_bits);
+ kdev_t dev = swapf->i_dev;
+ int block_size;
+ int zones[PAGE_SIZE/512];
+ int zones_used;
+
+ block_size = swapf->i_sb->s_blocksize;
+ for (i=0, j=0; j< PAGE_SIZE ; i++, j += block_size)
+ if (!(zones[i] = bmap(swapf,block++))) {
+ printk("blkdevfile_rw_page: bad swap file\n");
+ return 0;
+ }
+ zones_used = i;
+
+ /* block_size == PAGE_SIZE/zones_used */
+ brw_page(rw, page, dev, zones, block_size);
+ return 1;
+}
+
+static struct swap_ops blkdevfile_swap_ops = {
+ blkdevfile_swap_open,
+ blkdevfile_swap_release,
+ blkdevfile_rw_page
+ };
+
+int __init blkdev_swap_init(void)
+{
+ (void)register_swap_method(BLKDEV_SWAP_ID, &blkdev_swap_ops);
+ (void)register_swap_method(BLKDEV_FILE_SWAP_ID, &blkdevfile_swap_ops);
+ return 0;
+}
+
+void __exit blkdev_swap_exit(void)
+{
+ unregister_swap_method(BLKDEV_SWAP_ID);
+ unregister_swap_method(BLKDEV_FILE_SWAP_ID);
+}
+
+module_init(blkdev_swap_init)
+module_exit(blkdev_swap_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Many. Stuffed into a module by cH (Claus-Justus Heine)");
+MODULE_DESCRIPTION("Swapping to partitions and files on local hard-disks");
diff -Nurb linux.orig/fs/buffer.c linux/fs/buffer.c
--- linux.orig/fs/buffer.c 2003-07-04 04:12:05.000000000 -0400
+++ linux/fs/buffer.c 2004-05-31 02:21:05.000000000 -0400
@@ -743,7 +743,7 @@
bh->b_private = private;
}
-static void end_buffer_io_async(struct buffer_head * bh, int uptodate)
+void end_buffer_io_async(struct buffer_head * bh, int uptodate)
{
static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
unsigned long flags;
@@ -2344,35 +2344,6 @@
return err;
}
-int brw_page(int rw, struct page *page, kdev_t dev, int b[], int size)
-{
- struct buffer_head *head, *bh;
-
- if (!PageLocked(page))
- panic("brw_page: page not locked for I/O");
-
- if (!page->buffers)
- create_empty_buffers(page, dev, size);
- head = bh = page->buffers;
-
- /* Stage 1: lock all the buffers */
- do {
- lock_buffer(bh);
- bh->b_blocknr = *(b++);
- set_bit(BH_Mapped, &bh->b_state);
- set_buffer_async_io(bh);
- bh = bh->b_this_page;
- } while (bh != head);
-
- /* Stage 2: start the IO */
- do {
- struct buffer_head *next = bh->b_this_page;
- submit_bh(rw, bh);
- bh = next;
- } while (bh != head);
- return 0;
-}
-
int block_symlink(struct inode *inode, const char *symname, int len)
{
struct address_space *mapping = inode->i_mapping;
diff -Nurb linux.orig/fs/nfs/Makefile linux/fs/nfs/Makefile
--- linux.orig/fs/nfs/Makefile 2003-07-04 04:12:07.000000000 -0400
+++ linux/fs/nfs/Makefile 2004-05-31 02:18:03.000000000 -0400
@@ -15,6 +15,14 @@
obj-$(CONFIG_ROOT_NFS) += nfsroot.o mount_clnt.o
obj-$(CONFIG_NFS_V3) += nfs3proc.o nfs3xdr.o
-obj-m := $(O_TARGET)
+obj-$(CONFIG_SWAP_VIA_NFS) += nfsswap.o
+ifeq ($(CONFIG_SWAP_VIA_NFS),m)
+export-objs := nfs_syms.o
+obj-y += nfs_syms.o
+endif
+
+ifeq ($(CONFIG_NFS_FS),m)
+obj-m += $(O_TARGET)
+endif
include $(TOPDIR)/Rules.make
diff -Nurb linux.orig/fs/nfs/file.c linux/fs/nfs/file.c
--- linux.orig/fs/nfs/file.c 2003-07-04 04:12:07.000000000 -0400
+++ linux/fs/nfs/file.c 2004-05-31 02:18:03.000000000 -0400
@@ -58,11 +58,6 @@
setattr: nfs_notify_change,
};
-/* Hack for future NFS swap support */
-#ifndef IS_SWAPFILE
-# define IS_SWAPFILE(inode) (0)
-#endif
-
/*
* Flush all dirty pages, and check for write errors.
*
@@ -217,8 +212,6 @@
inode->i_ino, (unsigned long) count, (unsigned long) *ppos);
result = -EBUSY;
- if (IS_SWAPFILE(inode))
- goto out_swapfile;
result = nfs_revalidate_inode(NFS_SERVER(inode), inode);
if (result)
goto out;
@@ -230,10 +223,6 @@
result = generic_file_write(file, buf, count, ppos);
out:
return result;
-
-out_swapfile:
- printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
- goto out;
}
/*
diff -Nurb linux.orig/fs/nfs/nfs_syms.c linux/fs/nfs/nfs_syms.c
--- linux.orig/fs/nfs/nfs_syms.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/fs/nfs/nfs_syms.c 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,10 @@
+#include <linux/config.h>
+#define __NO_VERSION__
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+
+EXPORT_SYMBOL(__nfs_refresh_inode);
+EXPORT_SYMBOL(nfs_write_attributes);
+
diff -Nurb linux.orig/fs/nfs/nfsswap.c linux/fs/nfs/nfsswap.c
--- linux.orig/fs/nfs/nfsswap.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/fs/nfs/nfsswap.c 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,350 @@
+/*
+ * Swapping to files located on NFS mounted volumes
+ * Copyright (c) 2000 Claus-Justus Heine
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/socket.h>
+#include <linux/smp_lock.h>
+#include <net/netswapping.h>
+#include <net/sock.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <asm/uaccess.h>
+
+#define NFSDBG_FACILITY NFSDBG_SWAP
+
+#define NFS_SWAP_ID "nfs file"
+
+/* we cache some values here. In principle, we only need the file.
+ */
+struct nfs_swap_data {
+ struct file *file;
+ struct inode *inode;
+ struct nfs_server *server;
+ struct socket *socket;
+};
+
+/* Nearly a clone of nfs_readpage_sync() in read.c, but "struct page" does not
+ * contain information about the file offset when swapping. So.
+ */
+static int nfs_read_swap_page(struct page *page,
+ struct nfs_server *server,
+ struct inode *inode,
+ struct file *file)
+{
+ unsigned int rsize = server->rsize;
+ unsigned int count = PAGE_SIZE;
+ unsigned int offset = 0; /* always at start of page */
+ int result, eof;
+ struct rpc_cred *cred;
+ struct nfs_fattr fattr;
+
+ cred = nfs_file_cred(file);
+
+ do {
+ if (count < rsize)
+ rsize = count;
+
+ lock_kernel();
+ result = NFS_PROTO(inode)->read(inode, cred,
+ &fattr,
+ NFS_RPC_SWAPFLAGS,
+ offset, rsize, page, &eof);
+ nfs_refresh_inode(inode, &fattr);
+ unlock_kernel();
+
+ /*
+ * Even if we had a partial success we can't mark the page
+ * cache valid.
+ */
+ if (result < 0) {
+ if (result == -EISDIR)
+ result = -EINVAL;
+ goto io_error;
+ }
+ count -= result;
+ offset += result;
+ if (result < rsize) /* NFSv2ism */
+ break;
+ } while (count);
+
+ if (count) {
+ char *kaddr = kmap(page);
+ memset(kaddr + offset, 0, count);
+ kunmap(page);
+ }
+ flush_dcache_page(page);
+ result = 0;
+
+io_error:
+ return result;
+}
+
+/* Like nfs_writepage_sync(), but when swapping page->index does not encode
+ * the offset in the swap file alone.
+ *
+ */
+static int nfs_write_swap_page(struct page *page,
+ struct nfs_server *server,
+ struct inode *inode,
+ struct file *file)
+{
+ struct rpc_cred *cred;
+ unsigned int wsize = server->wsize;
+ unsigned int count = PAGE_SIZE;
+ unsigned int offset = 0;
+ int result;
+ struct nfs_writeverf verf;
+ struct nfs_fattr fattr;
+
+ cred = nfs_file_cred(file);
+
+ do {
+ if (count < wsize)
+ wsize = count;
+
+ lock_kernel();
+ result = NFS_PROTO(inode)->write(inode, cred, &fattr,
+ NFS_RW_SWAP|NFS_RW_SYNC,
+ offset, wsize, page, &verf);
+ nfs_write_attributes(inode, &fattr);
+ unlock_kernel();
+
+ if (result < 0) {
+ goto io_error;
+ }
+ if (result != wsize)
+ printk("NFS: short write, wsize=%u, result=%d\n",
+ wsize, result);
+ offset += wsize;
+ count -= wsize;
+ /*
+ * If we've extended the file, update the inode
+ * now so we don't invalidate the cache.
+ */
+ if (offset > inode->i_size)
+ inode->i_size = offset;
+ } while (count);
+
+ result = 0;
+
+io_error:
+
+ return result;
+}
+
+/* Unluckily (for us) form 2.4.19 -> 2.4.20 the nfs-proc's where
+ * changed and expect now a proper file-mapping page, where index
+ * encodes the offset alone.
+ *
+ * What we do: we save the original value of page->index, initialize
+ * page->index to what the NFS/sun-rpc subsystem expects and restore
+ * the index later.
+ */
+static int nfs_rw_swap_page(int rw, struct page *page,
+ unsigned long offset, void *dptr)
+{
+ int error;
+ struct nfs_swap_data *data = dptr;
+ unsigned long alloc_flag = current->flags & PF_MEMALLOC;
+ unsigned long page_index;
+
+ if (!PageLocked(page))
+ panic("nfs_rw_swap_page: page not locked for I/O");
+
+ /* prevent memory deadlocks */
+ if (!(current->flags & PF_MEMALLOC)) {
+ dprintk("nfs_rw_swap_page: Setting PF_MEMALLOC\n");
+ }
+ current->flags |= PF_MEMALLOC;
+
+ /* now tweak the page->index field ... */
+ page_index = page->index;
+ page->index = ((loff_t)offset*(loff_t)PAGE_SIZE) >> PAGE_CACHE_SHIFT;
+
+ if (rw == WRITE) {
+ error = nfs_write_swap_page(page,
+ data->server,
+ data->inode,
+ data->file);
+ } else {
+ error = nfs_read_swap_page(page,
+ data->server,
+ data->inode,
+ data->file);
+ }
+
+ if (!alloc_flag) {
+ current->flags &= ~PF_MEMALLOC;
+ }
+
+ /* now restore the page->index field ... */
+ page->index = page_index;
+
+ if (error) {
+ /* Must mark the page invalid after I/O error */
+ SetPageError(page);
+ ClearPageUptodate(page);
+ } else {
+ ClearPageError(page);
+ SetPageUptodate(page);
+ }
+
+ if (!error) { /* in case of an error rw_swap_page() likes to unlock
+ * itself.
+ */
+ UnlockPage(page);
+ }
+
+ return error < 0 ? 0 : 1;
+}
+
+static int is_nfsfile_swapping(unsigned int flags,
+ struct file * swapf,
+ void * data)
+{
+ struct file * filp = (struct file *) data;
+
+ /* Only check filp's that don't match the one already opened
+ * for us by sys_swapon(). Otherwise, we will always flag a
+ * busy swap file.
+ */
+
+ if (swapf != filp) {
+ if (filp->f_dentry->d_inode == swapf->f_dentry->d_inode)
+ return 1;
+ }
+ return 0;
+}
+
+static int nfs_swap_open(struct file *swapf, void **dptr)
+{
+ int error = 0;
+ int swapfilesize;
+ struct nfs_swap_data *data;
+ int on = 1;
+ mm_segment_t fs;
+ struct inode *inode = swapf->f_dentry->d_inode;
+
+ MOD_INC_USE_COUNT;
+
+ if (!S_ISREG(inode->i_mode)) {
+ dprintk("nfs_swap_open: can't handle this swap file: %s\n",
+ swapf->f_dentry->d_name.name);
+ error = 0; /* not for us */
+ goto bad_swap;
+ }
+ /* determine whether this file really is located on an NFS mounted
+ * volume
+ */
+ if (!inode->i_sb || inode->i_sb->s_magic != NFS_SUPER_MAGIC) {
+ dprintk("nfs_swap_open: %s is not an NFS file.\n",
+ swapf->f_dentry->d_name.name);
+ error = 0; /* not for us */
+ goto bad_swap;
+ }
+
+ if (swap_run_test(is_nfsfile_swapping, swapf)) {
+ dprintk("nfs_swap_open: already swapping to %s\n",
+ swapf->f_dentry->d_name.name);
+ error = -EBUSY;
+ goto bad_swap;
+ }
+ swapfilesize = inode->i_size >> PAGE_SHIFT;
+ if ((data = kmalloc(sizeof(*data), GFP_KERNEL)) == NULL) {
+ error = -ENOMEM;
+ goto bad_swap;
+ }
+ data->file = swapf;
+ data->inode = inode;
+ data->server = NFS_SERVER(inode);
+ data->socket = data->server->client->cl_xprt->sock;
+
+ /* set socket option SO_SWAPPING */
+ fs = get_fs();
+ set_fs(KERNEL_DS);
+ error = sock_setsockopt(data->socket, SOL_SOCKET, SO_SWAPPING,
+ (char *)&on, sizeof(on));
+ set_fs(fs);
+ if (error) {
+ dprintk("nfs_swap_open: error setting SO_SWAPPING\n");
+ goto bad_swap_2;
+ }
+
+ *dptr = data;
+ return swapfilesize;
+
+ bad_swap_2:
+ kfree(data);
+ bad_swap:
+ MOD_DEC_USE_COUNT;
+ return error;
+}
+
+static int nfs_swap_release(struct file *swapf, void *dptr)
+{
+ struct nfs_swap_data *data = (struct nfs_swap_data *)dptr;
+ int off = 0;
+ mm_segment_t fs;
+ int error;
+
+#if 1
+ if (swapf != data->file ||
+ swapf->f_dentry->d_inode != data->inode ||
+ !swapf->f_dentry->d_inode->i_sb ||
+ swapf->f_dentry->d_inode->i_sb->s_magic != NFS_SUPER_MAGIC ||
+ NFS_SERVER(swapf->f_dentry->d_inode) != data->server ||
+ data->socket != data->server->client->cl_xprt->sock) {
+ panic("nfs_swap_release: nfs swap data messed up");
+ }
+#endif
+
+ /* remove socket option SO_SWAPPING */
+ fs = get_fs();
+ set_fs(KERNEL_DS);
+ error = sock_setsockopt(data->socket, SOL_SOCKET, SO_SWAPPING,
+ (char *)&off, sizeof(off));
+ set_fs(fs);
+ if (error) {
+ dprintk("nfs_swap_open: error clearing SO_SWAPPING\n");
+ }
+ kfree(data);
+ MOD_DEC_USE_COUNT;
+ return error;
+}
+
+static struct swap_ops nfs_swap_ops = {
+ open: nfs_swap_open,
+ release: nfs_swap_release,
+ rw_page: nfs_rw_swap_page
+};
+
+int __init nfs_swap_init(void)
+{
+ (void)register_swap_method(NFS_SWAP_ID, &nfs_swap_ops);
+ return 0;
+}
+
+void __exit nfs_swap_exit(void)
+{
+ unregister_swap_method(NFS_SWAP_ID);
+}
+
+module_init(nfs_swap_init)
+module_exit(nfs_swap_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("(c) 1996-2002 cH (Claus-Justus Heine)");
+MODULE_DESCRIPTION("Swapping to files located on volumes mounted via NFS");
diff -Nurb linux.orig/fs/nfs/read.c linux/fs/nfs/read.c
--- linux.orig/fs/nfs/read.c 2003-07-04 04:12:08.000000000 -0400
+++ linux/fs/nfs/read.c 2004-05-31 02:18:03.000000000 -0400
@@ -50,11 +50,6 @@
*/
static void nfs_readpage_result(struct rpc_task *task);
-/* Hack for future NFS swap support */
-#ifndef IS_SWAPFILE
-# define IS_SWAPFILE(inode) (0)
-#endif
-
static kmem_cache_t *nfs_rdata_cachep;
static __inline__ struct nfs_read_data *nfs_readdata_alloc(void)
@@ -92,7 +87,6 @@
int rsize = NFS_SERVER(inode)->rsize;
int result;
int count = PAGE_CACHE_SIZE;
- int flags = IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0;
int eof;
dprintk("NFS: nfs_readpage_sync(%p)\n", page);
@@ -114,7 +108,7 @@
offset, rsize, page);
lock_kernel();
- result = NFS_PROTO(inode)->read(inode, cred, &fattr, flags,
+ result = NFS_PROTO(inode)->read(inode, cred, &fattr, 0,
offset, rsize, page, &eof);
nfs_refresh_inode(inode, &fattr);
unlock_kernel();
@@ -246,7 +240,7 @@
task = &data->task;
/* N.B. Do we need to test? Never called for swapfile inode */
- flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
+ flags = RPC_TASK_ASYNC;
nfs_read_rpcsetup(head, data);
@@ -476,8 +470,6 @@
}
error = nfs_readpage_sync(file, inode, page);
- if (error < 0 && IS_SWAPFILE(inode))
- printk("Aiee.. nfs swap-in of page failed!\n");
out:
return error;
diff -Nurb linux.orig/fs/nfs/write.c linux/fs/nfs/write.c
--- linux.orig/fs/nfs/write.c 2003-07-04 04:12:08.000000000 -0400
+++ linux/fs/nfs/write.c 2004-05-31 02:20:47.000000000 -0400
@@ -3,7 +3,6 @@
#include <linux/config.h>
#include <linux/types.h>
#include <linux/slab.h>
-#include <linux/swap.h>
#include <linux/pagemap.h>
#include <linux/file.h>
@@ -46,11 +45,6 @@
static void nfs_commit_done(struct rpc_task *);
#endif
-/* Hack for future NFS swap support */
-#ifndef IS_SWAPFILE
-# define IS_SWAPFILE(inode) (0)
-#endif
-
static kmem_cache_t *nfs_wdata_cachep;
static __inline__ struct nfs_write_data *nfs_writedata_alloc(void)
@@ -82,7 +76,7 @@
* For the moment, we just call nfs_refresh_inode().
*/
static __inline__ int
-nfs_write_attributes(struct inode *inode, struct nfs_fattr *fattr)
+__nfs_write_attributes(struct inode *inode, struct nfs_fattr *fattr)
{
if ((fattr->valid & NFS_ATTR_FATTR) && !(fattr->valid & NFS_ATTR_WCC)) {
fattr->pre_size = NFS_CACHE_ISIZE(inode);
@@ -93,6 +87,11 @@
return nfs_refresh_inode(inode, fattr);
}
+int nfs_write_attributes(struct inode *inode, struct nfs_fattr *fattr)
+{
+ return __nfs_write_attributes(inode, fattr);
+}
+
/*
* Write a page synchronously.
* Offset is the data offset within the page.
@@ -104,8 +103,7 @@
struct rpc_cred *cred = NULL;
loff_t base;
unsigned int wsize = NFS_SERVER(inode)->wsize;
- int result, refresh = 0, written = 0, flags;
- u8 *buffer;
+ int result, refresh = 0, written = 0;
struct nfs_fattr fattr;
struct nfs_writeverf verf;
@@ -121,15 +119,14 @@
base = page_offset(page) + offset;
- flags = ((IS_SWAPFILE(inode)) ? NFS_RW_SWAP : 0) | NFS_RW_SYNC;
-
do {
- if (count < wsize && !IS_SWAPFILE(inode))
+ if (count < wsize)
wsize = count;
- result = NFS_PROTO(inode)->write(inode, cred, &fattr, flags,
+ result = NFS_PROTO(inode)->write(inode, cred, &fattr,
+ NFS_RW_SYNC,
offset, wsize, page, &verf);
- nfs_write_attributes(inode, &fattr);
+ __nfs_write_attributes(inode, &fattr);
if (result < 0) {
/* Must mark the page invalid after I/O error */
@@ -140,7 +137,6 @@
printk("NFS: short write, wsize=%u, result=%d\n",
wsize, result);
refresh = 1;
- buffer += wsize;
base += wsize;
offset += wsize;
written += wsize;
@@ -979,7 +975,7 @@
}
#endif
- nfs_write_attributes(inode, resp->fattr);
+ __nfs_write_attributes(inode, resp->fattr);
while (!list_empty(&data->pages)) {
req = nfs_list_entry(data->pages.next);
nfs_list_remove_request(req);
@@ -1133,7 +1129,7 @@
if (nfs_async_handle_jukebox(task))
return;
- nfs_write_attributes(inode, resp->fattr);
+ __nfs_write_attributes(inode, resp->fattr);
while (!list_empty(&data->pages)) {
req = nfs_list_entry(data->pages.next);
nfs_list_remove_request(req);
diff -Nurb linux.orig/include/linux/fs.h linux/include/linux/fs.h
--- linux.orig/include/linux/fs.h 2004-05-31 02:06:19.000000000 -0400
+++ linux/include/linux/fs.h 2004-05-31 02:18:03.000000000 -0400
@@ -1500,6 +1500,10 @@
extern int inode_change_ok(struct inode *, struct iattr *);
extern int inode_setattr(struct inode *, struct iattr *);
+/* for swapping to block devices */
+void create_empty_buffers(struct page *page, kdev_t dev, unsigned long blocksize);
+void end_buffer_io_async(struct buffer_head * bh, int uptodate);
+
/*
* Common dentry functions for inclusion in the VFS
* or in other stackable file systems. Some of these
diff -Nurb linux.orig/include/linux/nfs_fs.h linux/include/linux/nfs_fs.h
--- linux.orig/include/linux/nfs_fs.h 2004-05-31 02:06:28.000000000 -0400
+++ linux/include/linux/nfs_fs.h 2004-05-31 02:18:03.000000000 -0400
@@ -40,8 +40,8 @@
*/
#define NFS_MAX_DIRCACHE 16
-#define NFS_MAX_FILE_IO_BUFFER_SIZE 32768
-#define NFS_DEF_FILE_IO_BUFFER_SIZE 4096
+#define NFS_MAX_FILE_IO_BUFFER_SIZE (8*PAGE_SIZE)
+#define NFS_DEF_FILE_IO_BUFFER_SIZE PAGE_SIZE
/*
* The upper limit on timeouts for the exponential backoff algorithm.
@@ -205,6 +205,8 @@
extern int nfs_writepage(struct page *);
extern int nfs_flush_incompatible(struct file *file, struct page *page);
extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
+extern int nfs_write_attributes(struct inode *inode, struct nfs_fattr *fattr);
+
/*
* Try to write back everything synchronously (but check the
* return value!)
@@ -375,6 +377,7 @@
#define NFSDBG_XDR 0x0020
#define NFSDBG_FILE 0x0040
#define NFSDBG_ROOT 0x0080
+#define NFSDBG_SWAP 0x0100
#define NFSDBG_ALL 0xFFFF
#ifdef __KERNEL__
diff -Nurb linux.orig/include/linux/slab.h linux/include/linux/slab.h
--- linux.orig/include/linux/slab.h 2004-05-31 02:06:19.000000000 -0400
+++ linux/include/linux/slab.h 2004-05-31 02:18:03.000000000 -0400
@@ -39,6 +39,7 @@
#define SLAB_HWCACHE_ALIGN 0x00002000UL /* align objs on a h/w cache lines */
#define SLAB_CACHE_DMA 0x00004000UL /* use GFP_DMA memory */
#define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL /* force alignment */
+#define SLAB_LOW_GFP_ORDER 0x00010000UL /* use as low a gfp order as possible */
/* flags passed to a constructor func */
#define SLAB_CTOR_CONSTRUCTOR 0x001UL /* if not set, then deconstructor */
diff -Nurb linux.orig/include/linux/swap.h linux/include/linux/swap.h
--- linux.orig/include/linux/swap.h 2004-05-31 02:06:19.000000000 -0400
+++ linux/include/linux/swap.h 2004-05-31 02:18:03.000000000 -0400
@@ -58,15 +58,29 @@
#define SWAP_MAP_MAX 0x7fff
#define SWAP_MAP_BAD 0x8000
+struct swap_ops {
+ int (*open)(struct file *swapf, void **data);
+ int (*release)(struct file *swapf, void *data);
+ int (*rw_page)(int rw,
+ struct page *page, unsigned long offset, void *data);
+};
+
+struct swap_method {
+ struct swap_method *next;
+ char * name;
+ struct swap_ops *ops;
+ int use_count;
+};
+
/*
* The in-memory structure used to track swap areas.
*/
struct swap_info_struct {
unsigned int flags;
- kdev_t swap_device;
+ struct file *swap_file;
+ struct swap_method *method;
+ void *data;
spinlock_t sdev_lock;
- struct dentry * swap_file;
- struct vfsmount *swap_vfsmnt;
unsigned short * swap_map;
unsigned int lowest_bit;
unsigned int highest_bit;
@@ -141,11 +155,15 @@
extern int total_swap_pages;
extern unsigned int nr_swapfiles;
extern struct swap_info_struct swap_info[];
-extern int is_swap_partition(kdev_t);
+extern int register_swap_method(char *name, struct swap_ops *ops);
+extern int unregister_swap_method(char *name);
+extern int swap_run_test(int (*test_fct)(unsigned int flags,
+ struct file *swap_file,
+ void *testdata), void *testdata);
extern void si_swapinfo(struct sysinfo *);
extern swp_entry_t get_swap_page(void);
-extern void get_swaphandle_info(swp_entry_t, unsigned long *, kdev_t *,
- struct inode **);
+struct swap_method *get_swaphandle_info(swp_entry_t entry,
+ unsigned long *offset, void **data);
extern int swap_duplicate(swp_entry_t);
extern int swap_count(struct page *);
extern int valid_swaphandles(swp_entry_t, unsigned long *);
diff -Nurb linux.orig/include/net/netswapping.h linux/include/net/netswapping.h
--- linux.orig/include/net/netswapping.h 1969-12-31 19:00:00.000000000 -0500
+++ linux/include/net/netswapping.h 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,47 @@
+#ifndef _LINUX_NETSWAPPING_H
+#define _LINUX_NETSWAPPING_H
+
+#include <linux/swap.h>
+#include <linux/init.h>
+
+/* It is a mess. Socket options are defined in asm-ARCH/socket.h */
+
+#define SO_SWAPPING 0x00100000 /* hopefully not used by anybody else */
+
+#ifdef __KERNEL__
+
+#define CTL_NETSWAP 0x00100000
+
+enum {
+ NET_SWAP_DROPPED = 1,
+ NET_SWAP_DROP_THRESHOLD = 2,
+ NET_SWAP_SOCK_COUNT = 3
+};
+
+extern unsigned int netswap_free_pages_min;
+extern int netswap_sock_count;
+extern unsigned int netswap_dropped;
+
+/* this is "#defined" and not inline because sock.h includes us, but we need
+ * the "struct sock" definition.
+ */
+#define netswap_low_memory(sk, skb) \
+({ \
+ int _ret = 0; \
+ \
+ if (netswap_sock_count > 0 && /* anybody swapping via network? */ \
+ !(sk)->swapping && /* but we are not needed for swapping */ \
+ nr_free_pages() < netswap_free_pages_min) { /* so drop us */ \
+ printk("netswap_low_memory: " \
+ "dropping skb 0x%p@0x%p\n", skb, sk); \
+ netswap_dropped ++; \
+ _ret = 1; \
+ } \
+ _ret; \
+})
+
+extern int __init netswap_init(void);
+
+#endif
+
+#endif
diff -Nurb linux.orig/include/net/sock.h linux/include/net/sock.h
--- linux.orig/include/net/sock.h 2004-05-31 02:07:17.000000000 -0400
+++ linux/include/net/sock.h 2004-05-31 02:18:03.000000000 -0400
@@ -103,6 +103,10 @@
#include <linux/filter.h>
#endif
+#ifdef CONFIG_NETSWAP
+#include <net/netswapping.h>
+#endif
+
#include <asm/atomic.h>
#include <net/dst.h>
@@ -536,6 +540,12 @@
no_check,
broadcast,
bsdism;
+#ifdef CONFIG_NETSWAP
+ /* Increased by SO_SWAPPING with arg != 0, decreased by
+ * SO_SWAPPING with arg 0
+ */
+ int swapping;
+#endif
unsigned char debug;
unsigned char rcvtstamp;
unsigned char use_write_queue;
@@ -1165,6 +1175,11 @@
return err; /* Toss packet */
}
#endif /* CONFIG_FILTER */
+#ifdef CONFIG_NETSWAP
+ /* an inline function defined in net/netswapping.h */
+ if (netswap_low_memory(sk, skb))
+ return -ENOMEM;
+#endif /* CONFIG_NETSWAP */
skb->dev = NULL;
skb_set_owner_r(skb, sk);
diff -Nurb linux.orig/kernel/ksyms.c linux/kernel/ksyms.c
--- linux.orig/kernel/ksyms.c 2004-05-31 02:02:43.000000000 -0400
+++ linux/kernel/ksyms.c 2004-05-31 02:18:03.000000000 -0400
@@ -41,6 +41,7 @@
#include <linux/mm.h>
#include <linux/capability.h>
#include <linux/highuid.h>
+#include <linux/swapctl.h>
#include <linux/brlock.h>
#include <linux/fs.h>
#include <linux/tty.h>
@@ -127,6 +128,11 @@
EXPORT_SYMBOL(kmap_prot);
EXPORT_SYMBOL(kmap_pte);
#endif
+EXPORT_SYMBOL(nr_free_pages);
+/* EXPORT_SYMBOL(freepages); */
+EXPORT_SYMBOL(register_swap_method);
+EXPORT_SYMBOL(unregister_swap_method);
+EXPORT_SYMBOL(swap_run_test);
/* filesystem internal functions */
EXPORT_SYMBOL(def_blk_fops);
@@ -531,7 +537,7 @@
EXPORT_SYMBOL(make_bad_inode);
EXPORT_SYMBOL(is_bad_inode);
EXPORT_SYMBOL(event);
-EXPORT_SYMBOL(brw_page);
+EXPORT_SYMBOL(end_buffer_io_async);
EXPORT_SYMBOL(__inode_dir_notify);
#ifdef CONFIG_UID16
diff -Nurb linux.orig/mm/page_io.c linux/mm/page_io.c
--- linux.orig/mm/page_io.c 2003-07-04 04:12:29.000000000 -0400
+++ linux/mm/page_io.c 2004-05-31 02:18:03.000000000 -0400
@@ -36,11 +36,8 @@
static int rw_swap_page_base(int rw, swp_entry_t entry, struct page *page)
{
unsigned long offset;
- int zones[PAGE_SIZE/512];
- int zones_used;
- kdev_t dev = 0;
- int block_size;
- struct inode *swapf = 0;
+ struct swap_method *method;
+ void *data;
if (rw == READ) {
ClearPageUptodate(page);
@@ -48,30 +45,11 @@
} else
kstat.pswpout++;
- get_swaphandle_info(entry, &offset, &dev, &swapf);
- if (dev) {
- zones[0] = offset;
- zones_used = 1;
- block_size = PAGE_SIZE;
- } else if (swapf) {
- int i, j;
- unsigned int block = offset
- << (PAGE_SHIFT - swapf->i_sb->s_blocksize_bits);
-
- block_size = swapf->i_sb->s_blocksize;
- for (i=0, j=0; j< PAGE_SIZE ; i++, j += block_size)
- if (!(zones[i] = bmap(swapf,block++))) {
- printk("rw_swap_page: bad swap file\n");
- return 0;
- }
- zones_used = i;
- dev = swapf->i_dev;
- } else {
+ method = get_swaphandle_info(entry, &offset, &data);
+ if (!method || !method->ops->rw_page(rw, page, offset, data)) {
return 0;
}
- /* block_size == PAGE_SIZE/zones_used */
- brw_page(rw, page, dev, zones, block_size);
return 1;
}
diff -Nurb linux.orig/mm/slab.c linux/mm/slab.c
--- linux.orig/mm/slab.c 2003-07-04 04:12:29.000000000 -0400
+++ linux/mm/slab.c 2004-05-31 02:18:03.000000000 -0400
@@ -111,10 +111,12 @@
# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
SLAB_POISON | SLAB_HWCACHE_ALIGN | \
SLAB_NO_REAP | SLAB_CACHE_DMA | \
- SLAB_MUST_HWCACHE_ALIGN)
+ SLAB_MUST_HWCACHE_ALIGN | \
+ SLAB_LOW_GFP_ORDER)
#else
# define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \
- SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN)
+ SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
+ SLAB_LOW_GFP_ORDER)
#endif
/*
@@ -247,8 +249,13 @@
};
/* internal c_flags */
-#define CFLGS_OFF_SLAB 0x010000UL /* slab management in own cache */
-#define CFLGS_OPTIMIZE 0x020000UL /* optimized slab lookup */
+#define CFLGS_OFF_SLAB 0x020000UL /* slab management in own cache */
+#define CFLGS_OPTIMIZE 0x040000UL /* optimized slab lookup */
+#define CFLGS_MASK (CFLGS_OFF_SLAB | CFLGS_OPTIMIZE)
+
+#if (CFLGS_MASK & CREATE_MASK)
+# error BUG: internal and external SLAB flags overlap
+#endif
/* c_dflags (dynamic flags). Need to hold the spinlock to access this member */
#define DFLGS_GROWN 0x000001UL /* don't reap a recently grown */
@@ -452,7 +459,12 @@
snprintf(name, sizeof(name), "size-%Zd",sizes->cs_size);
if (!(sizes->cs_cachep =
kmem_cache_create(name, sizes->cs_size,
- 0, SLAB_HWCACHE_ALIGN, NULL, NULL))) {
+ 0,
+#if CONFIG_NETSWAP
+ SLAB_LOW_GFP_ORDER| /* sorry */
+#endif
+ SLAB_HWCACHE_ALIGN,
+ NULL, NULL))) {
BUG();
}
@@ -731,6 +743,8 @@
break;
if (!cachep->num)
goto next;
+ if (cachep->gfporder == 0 && (flags & SLAB_LOW_GFP_ORDER))
+ break;
if (flags & CFLGS_OFF_SLAB && cachep->num > offslab_limit) {
/* Oops, this num of objs will cause problems. */
cachep->gfporder--;
diff -Nurb linux.orig/mm/swapfile.c linux/mm/swapfile.c
--- linux.orig/mm/swapfile.c 2003-07-04 04:12:29.000000000 -0400
+++ linux/mm/swapfile.c 2004-05-31 02:18:03.000000000 -0400
@@ -11,12 +11,17 @@
#include <linux/swap.h>
#include <linux/swapctl.h>
#include <linux/blkdev.h> /* for blk_size */
+#include <linux/file.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/shm.h>
#include <asm/pgtable.h>
+#ifdef CONFIG_KMOD
+#include <linux/kmod.h>
+#endif
+
spinlock_t swaplock = SPIN_LOCK_UNLOCKED;
unsigned int nr_swapfiles;
int total_swap_pages;
@@ -31,8 +36,78 @@
struct swap_info_struct swap_info[MAX_SWAPFILES];
+static struct swap_method *swap_methods = NULL;
+
#define SWAPFILE_CLUSTER 256
+int register_swap_method(char *name, struct swap_ops *ops)
+{
+ struct swap_method *pos;
+ struct swap_method *new;
+ int result = 0;
+
+ lock_kernel();
+
+ for (pos = swap_methods; pos; pos = pos->next) {
+ if (strcmp(pos->name, name) == 0) {
+ printk(KERN_ERR "register_swap_method: "
+ "method %s already registered\n", name);
+ result = -EBUSY;
+ goto out;
+ }
+ }
+
+ if (!(new = kmalloc(sizeof(*new), GFP_KERNEL))) {
+ printk(KERN_ERR "register_swap_method: "
+ "no memory for new method \"%s\"\n", name);
+ result = -ENOMEM;
+ goto out;
+ }
+
+ new->name = name;
+ new->ops = ops;
+ new->use_count = 0;
+
+ /* ok, insert at top of list */
+ printk("register_swap_method: method %s\n", name);
+ new->next = swap_methods;
+ swap_methods = new;
+ out:
+ unlock_kernel();
+ return result;
+}
+
+int unregister_swap_method(char *name)
+{
+ struct swap_method **method, *next;
+ int result = 0;
+
+ lock_kernel();
+
+ for (method = &swap_methods; *method; method = &(*method)->next) {
+ if (strcmp((*method)->name, name) == 0) {
+ if ((*method)->use_count > 0) {
+ printk(KERN_ERR "unregister_swap_method: "
+ "method \"%s\" is in use\n", name);
+ result = -EBUSY;
+ goto out;
+ }
+
+ next = (*method)->next;
+ kfree(*method);
+ *method = next;
+ printk("unregister_swap_method: method %s\n", name);
+ goto out;
+ }
+ }
+ /* not found */
+ printk("unregister_swap_method: no such method %s\n", name);
+ result = -ENOENT;
+ out:
+ unlock_kernel();
+ return result;
+}
+
static inline int scan_swap_map(struct swap_info_struct *si)
{
unsigned long offset;
@@ -711,13 +786,14 @@
struct nameidata nd;
int i, type, prev;
int err;
+ struct file *swap_file;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = user_path_walk(specialfile, &nd);
if (err)
- goto out;
+ return err;
lock_kernel();
prev = -1;
@@ -725,15 +801,20 @@
for (type = swap_list.head; type >= 0; type = swap_info[type].next) {
p = swap_info + type;
if ((p->flags & SWP_WRITEOK) == SWP_WRITEOK) {
- if (p->swap_file == nd.dentry)
+ if (p->swap_file &&
+ p->swap_file->f_dentry == nd.dentry)
break;
}
prev = type;
}
err = -EINVAL;
+ /* p->swap_file contains all needed info, no need to keep nd, so
+ * release it now.
+ */
+ path_release(&nd);
if (type < 0) {
swap_list_unlock();
- goto out_dput;
+ goto out;
}
if (prev < 0) {
@@ -767,32 +848,30 @@
total_swap_pages += p->pages;
p->flags = SWP_WRITEOK;
swap_list_unlock();
- goto out_dput;
+ goto out;
}
- if (p->swap_device)
- blkdev_put(p->swap_file->d_inode->i_bdev, BDEV_SWAP);
- path_release(&nd);
+ if (p->method->ops->release)
+ p->method->ops->release(p->swap_file, p->data);
swap_list_lock();
swap_device_lock(p);
- nd.mnt = p->swap_vfsmnt;
- nd.dentry = p->swap_file;
- p->swap_vfsmnt = NULL;
+ p->method->use_count --;
+ p->method = NULL;
+ p->data = NULL;
+ swap_file = p->swap_file;
p->swap_file = NULL;
- p->swap_device = 0;
p->max = 0;
swap_map = p->swap_map;
p->swap_map = NULL;
p->flags = 0;
swap_device_unlock(p);
swap_list_unlock();
+ filp_close(swap_file, NULL);
vfree(swap_map);
err = 0;
-out_dput:
- unlock_kernel();
- path_release(&nd);
out:
+ unlock_kernel();
return err;
}
@@ -805,18 +884,17 @@
if (!page)
return -ENOMEM;
- len += sprintf(buf, "Filename\t\t\tType\t\tSize\tUsed\tPriority\n");
+ len += sprintf(buf, "%-32s%-16s%-8s%-8sPriority\n",
+ "Filename", "Type", "Size", "Used");
for (i = 0 ; i < nr_swapfiles ; i++, ptr++) {
if ((ptr->flags & SWP_USED) && ptr->swap_map) {
- char * path = d_path(ptr->swap_file, ptr->swap_vfsmnt,
+ char * path = d_path(ptr->swap_file->f_dentry,
+ ptr->swap_file->f_vfsmnt,
page, PAGE_SIZE);
len += sprintf(buf + len, "%-31s ", path);
- if (!ptr->swap_device)
- len += sprintf(buf + len, "file\t\t");
- else
- len += sprintf(buf + len, "partition\t");
+ len += sprintf(buf + len, "%-15s ", ptr->method->name);
usedswap = 0;
for (j = 0; j < ptr->max; ++j)
@@ -827,7 +905,7 @@
default:
usedswap++;
}
- len += sprintf(buf + len, "%d\t%d\t%d\n", ptr->pages << (PAGE_SHIFT - 10),
+ len += sprintf(buf + len, "%-8d%-8d%d\n", ptr->pages << (PAGE_SHIFT - 10),
usedswap << (PAGE_SHIFT - 10), ptr->prio);
}
}
@@ -835,18 +913,55 @@
return len;
}
-int is_swap_partition(kdev_t dev) {
+/* apply a test function to all active swap objects. E.g. for checking
+ * whether a partition is used for swapping
+ */
+int swap_run_test(int (*test_fct)(unsigned int flags,
+ struct file * swap_file,
+ void *testdata), void *testdata)
+{
struct swap_info_struct *ptr = swap_info;
int i;
for (i = 0 ; i < nr_swapfiles ; i++, ptr++) {
- if (ptr->flags & SWP_USED)
- if (ptr->swap_device == dev)
+ if (ptr->swap_file &&
+ test_fct(ptr->flags, ptr->swap_file, testdata))
return 1;
}
return 0;
}
+/* Walk through the list of known swap method until somebody wants to
+ * handle this file. Pick the first one which claims to be able to
+ * swap to this kind of file.
+ *
+ * return value: < 0: error, 0: not found, > 0: swapfilesize
+ */
+int find_swap_method(struct file *swap_file,
+ struct swap_info_struct *p)
+{
+ int swapfilesize = 0;
+ struct swap_method *method;
+
+ p->method = NULL;
+ for (method = swap_methods; method; method = method->next) {
+ swapfilesize = method->ops->open(swap_file, &p->data);
+ if (swapfilesize == 0) {
+ continue;
+ }
+ if (swapfilesize > 0) {
+ p->method = method;
+ p->method->use_count ++;
+ p->swap_file = swap_file;
+ break;
+ }
+ if (swapfilesize < 0) {
+ break;
+ }
+ }
+ return swapfilesize;
+}
+
/*
* Written 01/25/92 by Simmule Turner, heavily changed by Linus.
*
@@ -855,8 +970,6 @@
asmlinkage long sys_swapon(const char * specialfile, int swap_flags)
{
struct swap_info_struct * p;
- struct nameidata nd;
- struct inode * swap_inode;
unsigned int type;
int i, j, prev;
int error;
@@ -866,8 +979,9 @@
int nr_good_pages = 0;
unsigned long maxpages = 1;
int swapfilesize;
- struct block_device *bdev = NULL;
unsigned short *swap_map;
+ char * tmp_specialfile;
+ struct file *swap_file;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -886,8 +1000,7 @@
nr_swapfiles = type+1;
p->flags = SWP_USED;
p->swap_file = NULL;
- p->swap_vfsmnt = NULL;
- p->swap_device = 0;
+ p->method = NULL;
p->swap_map = NULL;
p->lowest_bit = 0;
p->highest_bit = 0;
@@ -901,53 +1014,56 @@
p->prio = --least_priority;
}
swap_list_unlock();
- error = user_path_walk(specialfile, &nd);
- if (error)
+
+ /* Open the swap using filp_open. Bail out on any errors. */
+ tmp_specialfile = getname(specialfile);
+ if (IS_ERR(tmp_specialfile)) {
+ error = PTR_ERR(tmp_specialfile);
goto bad_swap_2;
+ }
+ p->swap_file = filp_open(tmp_specialfile, O_RDWR, 0600);
+ putname(tmp_specialfile);
+ if (IS_ERR(p->swap_file)) {
+ error = PTR_ERR(p->swap_file);
+ goto bad_swap_1;
+ }
- p->swap_file = nd.dentry;
- p->swap_vfsmnt = nd.mnt;
- swap_inode = nd.dentry->d_inode;
error = -EINVAL;
- if (S_ISBLK(swap_inode->i_mode)) {
- kdev_t dev = swap_inode->i_rdev;
- struct block_device_operations *bdops;
- devfs_handle_t de;
-
- p->swap_device = dev;
- set_blocksize(dev, PAGE_SIZE);
-
- bd_acquire(swap_inode);
- bdev = swap_inode->i_bdev;
- de = devfs_get_handle_from_inode(swap_inode);
- bdops = devfs_get_ops(de); /* Increments module use count */
- if (bdops) bdev->bd_op = bdops;
-
- error = blkdev_get(bdev, FMODE_READ|FMODE_WRITE, 0, BDEV_SWAP);
- devfs_put_ops(de);/*Decrement module use count now we're safe*/
- if (error)
- goto bad_swap_2;
- set_blocksize(dev, PAGE_SIZE);
- error = -ENODEV;
- if (!dev || (blk_size[MAJOR(dev)] &&
- !blk_size[MAJOR(dev)][MINOR(dev)]))
- goto bad_swap;
- swapfilesize = 0;
- if (blk_size[MAJOR(dev)])
- swapfilesize = blk_size[MAJOR(dev)][MINOR(dev)]
- >> (PAGE_SHIFT - 10);
- } else if (S_ISREG(swap_inode->i_mode))
- swapfilesize = swap_inode->i_size >> PAGE_SHIFT;
- else
- goto bad_swap;
+ swapfilesize = find_swap_method(p->swap_file, p);
+ if (swapfilesize < 0) {
+ error = swapfilesize;
+ goto bad_swap_1;
+ }
+#ifdef CONFIG_KMOD
+ if (swapfilesize == 0) {
+ (void)request_module("swapfile-mod");
+
+ swapfilesize = find_swap_method(p->swap_file, p);
+ if (swapfilesize < 0) {
+ error = swapfilesize;
+ goto bad_swap_1;
+ }
+ }
+#endif
+ if (swapfilesize == 0) {
+ printk("Don't know how to swap to this kind of file\n");
+ goto bad_swap_1; /* free swap map */
+ }
+
+ /* After this point, the swap-file has been opened by the swap
+ * method. We must make sure to use the bad_swap label for any
+ * errors.
+ */
error = -EBUSY;
for (i = 0 ; i < nr_swapfiles ; i++) {
struct swap_info_struct *q = &swap_info[i];
if (i == type || !q->swap_file)
continue;
- if (swap_inode->i_mapping == q->swap_file->d_inode->i_mapping)
+ if (p->swap_file->f_dentry->d_inode->i_mapping
+ ==
+ q->swap_file->f_dentry->d_inode->i_mapping)
goto bad_swap;
}
@@ -1083,17 +1199,27 @@
swap_list_unlock();
error = 0;
goto out;
+
bad_swap:
- if (bdev)
- blkdev_put(bdev, BDEV_SWAP);
+ if (p->method->ops->release)
+ p->method->ops->release(p->swap_file, p->data);
+ swap_list_lock();
+ p->method->use_count --;
+ p->method = NULL;
+ p->data = NULL;
+ swap_list_unlock();
+
+bad_swap_1:
+ swap_list_lock();
+ swap_file = p->swap_file;
+ p->swap_file = NULL;
+ swap_list_unlock();
+ filp_close(swap_file, NULL);
+
bad_swap_2:
+
swap_list_lock();
swap_map = p->swap_map;
- nd.mnt = p->swap_vfsmnt;
- nd.dentry = p->swap_file;
- p->swap_device = 0;
- p->swap_file = NULL;
- p->swap_vfsmnt = NULL;
p->swap_map = NULL;
p->flags = 0;
if (!(swap_flags & SWAP_FLAG_PREFER))
@@ -1101,7 +1227,7 @@
swap_list_unlock();
if (swap_map)
vfree(swap_map);
- path_release(&nd);
+
out:
if (swap_header)
free_page((long) swap_header);
@@ -1217,8 +1343,8 @@
/*
* Prior swap_duplicate protects against swap device deletion.
*/
-void get_swaphandle_info(swp_entry_t entry, unsigned long *offset,
- kdev_t *dev, struct inode **swapf)
+struct swap_method *get_swaphandle_info(swp_entry_t entry,
+ unsigned long *offset, void **data)
{
unsigned long type;
struct swap_info_struct *p;
@@ -1226,32 +1352,26 @@
type = SWP_TYPE(entry);
if (type >= nr_swapfiles) {
printk(KERN_ERR "rw_swap_page: %s%08lx\n", Bad_file, entry.val);
- return;
+ return NULL;
}
p = &swap_info[type];
*offset = SWP_OFFSET(entry);
if (*offset >= p->max && *offset != 0) {
printk(KERN_ERR "rw_swap_page: %s%08lx\n", Bad_offset, entry.val);
- return;
+ return NULL;
}
if (p->swap_map && !p->swap_map[*offset]) {
printk(KERN_ERR "rw_swap_page: %s%08lx\n", Unused_offset, entry.val);
- return;
+ return NULL;
}
if (!(p->flags & SWP_USED)) {
printk(KERN_ERR "rw_swap_page: %s%08lx\n", Unused_file, entry.val);
- return;
+ return NULL;
}
- if (p->swap_device) {
- *dev = p->swap_device;
- } else if (p->swap_file) {
- *swapf = p->swap_file->d_inode;
- } else {
- printk(KERN_ERR "rw_swap_page: no swap file or device\n");
- }
- return;
+ *data = p->data;
+ return p->method;
}
/*
diff -Nurb linux.orig/net/Config.in linux/net/Config.in
--- linux.orig/net/Config.in 2003-07-04 04:12:29.000000000 -0400
+++ linux/net/Config.in 2004-05-31 02:18:03.000000000 -0400
@@ -16,6 +16,9 @@
fi
bool 'Socket Filtering' CONFIG_FILTER
tristate 'Unix domain sockets' CONFIG_UNIX
+if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+ bool 'Swapping via network sockets (EXPERIMENTAL)' CONFIG_NETSWAP
+fi
bool 'TCP/IP networking' CONFIG_INET
if [ "$CONFIG_INET" = "y" ]; then
source net/ipv4/Config.in
diff -Nurb linux.orig/net/Makefile linux/net/Makefile
--- linux.orig/net/Makefile 2003-07-04 04:12:29.000000000 -0400
+++ linux/net/Makefile 2004-05-31 02:18:03.000000000 -0400
@@ -51,6 +51,7 @@
ifeq ($(CONFIG_NET),y)
obj-$(CONFIG_MODULES) += netsyms.o
obj-$(CONFIG_SYSCTL) += sysctl_net.o
+obj-$(CONFIG_NETSWAP) += netswapping.o
endif
include $(TOPDIR)/Rules.make
diff -Nurb linux.orig/net/core/sock.c linux/net/core/sock.c
--- linux.orig/net/core/sock.c 2003-10-14 04:09:32.000000000 -0400
+++ linux/net/core/sock.c 2004-05-31 02:18:03.000000000 -0400
@@ -402,6 +402,21 @@
ret = -ENONET;
break;
#endif
+#ifdef CONFIG_NETSWAP
+ case SO_SWAPPING:
+ if (valbool) {
+ if (!sk->swapping) {
+ netswap_sock_count ++;
+ }
+ sk->swapping ++;
+ } else if (sk->swapping > 0) {
+ sk->swapping --;
+ if (!sk->swapping) {
+ netswap_sock_count --;
+ }
+ }
+ break;
+#endif
/* We implement the SO_SNDLOWAT etc to
not be settable (1003.1g 5.3) */
default:
@@ -552,6 +567,12 @@
goto lenout;
}
+#ifdef CONFIG_NETSWAP
+ case SO_SWAPPING:
+ v.val = sk->swapping;
+ break;
+#endif
+
/* Dubious BSD thing... Probably nobody even uses it, but
* the UNIX standard wants it for whatever reason... -DaveM
*/
diff -Nurb linux.orig/net/ipv4/tcp_ipv4.c linux/net/ipv4/tcp_ipv4.c
--- linux.orig/net/ipv4/tcp_ipv4.c 2003-10-14 04:09:33.000000000 -0400
+++ linux/net/ipv4/tcp_ipv4.c 2004-05-31 02:18:03.000000000 -0400
@@ -1657,6 +1657,12 @@
if (filter && sk_filter(skb, filter))
goto discard;
#endif /* CONFIG_FILTER */
+#ifdef CONFIG_NETSWAP
+ /* tcp doesn't use sock_queue_rcv_skb() ... */
+ /* an inline function defined in net/netswapping.h */
+ if (netswap_low_memory(sk, skb))
+ goto discard;
+#endif /* CONFIG_NETSWAP */
IP_INC_STATS_BH(IpInDelivers);
diff -Nurb linux.orig/net/ipv6/tcp_ipv6.c linux/net/ipv6/tcp_ipv6.c
--- linux.orig/net/ipv6/tcp_ipv6.c 2003-10-14 04:09:34.000000000 -0400
+++ linux/net/ipv6/tcp_ipv6.c 2004-05-31 02:18:03.000000000 -0400
@@ -1424,6 +1424,12 @@
if (filter && sk_filter(skb, filter))
goto discard;
#endif /* CONFIG_FILTER */
+#ifdef CONFIG_NETSWAP
+ /* tcp doesn't use sock_queue_rcv_skb() ... */
+ /* an inline function defined in net/netswapping.h */
+ if (netswap_low_memory(sk, skb))
+ goto discard;
+#endif /* CONFIG_NETSWAP */
/*
* socket locking is here for SMP purposes as backlog rcv
diff -Nurb linux.orig/net/netswapping.c linux/net/netswapping.c
--- linux.orig/net/netswapping.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/net/netswapping.c 2004-05-31 02:18:03.000000000 -0400
@@ -0,0 +1,76 @@
+/*
+ * linux/net/swapping.c
+ *
+ * Support paging over network connections (inet only)
+ *
+ * (c) 2000 Claus-Justus Heine <heine@instmath.rwth-aachen.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapctl.h>
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/init.h>
+#include <net/netswapping.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+
+unsigned int netswap_dropped; /* statistics */
+unsigned int netswap_free_pages_min;
+int netswap_sock_count; /* how many sockets have swapping option set */
+
+#ifdef CONFIG_SYSCTL
+
+static ctl_table netswap_table[] = {
+ {NET_SWAP_DROPPED, "dropped",
+ &netswap_dropped, sizeof(int), 0644, NULL, &proc_dointvec },
+ {NET_SWAP_DROP_THRESHOLD, "threshold",
+ &netswap_free_pages_min, sizeof(int), 0644, NULL, &proc_dointvec },
+ {NET_SWAP_SOCK_COUNT, "sock_count",
+ &netswap_sock_count, sizeof(int), 0444, NULL, &proc_dointvec },
+ {0},
+};
+
+static struct ctl_table_header *netswap_sysctl_header;
+
+static ctl_table netswap_net_table[] = {
+ {CTL_NETSWAP, "swapping", NULL, 0, 0555, netswap_table},
+ {0}
+};
+
+static ctl_table netswap_root_table[] = {
+ {CTL_NET, "net", NULL, 0, 0555, netswap_net_table},
+ {0}
+};
+
+#endif
+
+int __init netswap_init(void)
+{
+ /* drop packets when below this threshold */
+ netswap_free_pages_min = 32 /* freepages.min */;
+#ifdef CONFIG_SYSCTL
+ netswap_sysctl_header = register_sysctl_table(netswap_root_table, 0);
+#endif
+ return 0;
+}
+
+void __exit netswap_exit(void)
+{
+#ifdef CONFIG_SYSCTL
+ unregister_sysctl_table(netswap_sysctl_header);
+#endif
+}
+
+/* linux/init.h -- VERY nice :-)
+ *
+ * On the other hand, we have no control over the order the initcalls
+ * are performed ...
+ *
+ * Actually, we are not compiled as module ...
+ */
+
+module_init(netswap_init)
+module_exit(netswap_exit)
diff -Nurb linux.orig/net/netsyms.c linux/net/netsyms.c
--- linux.orig/net/netsyms.c 2004-05-31 02:02:49.000000000 -0400
+++ linux/net/netsyms.c 2004-05-31 02:18:03.000000000 -0400
@@ -601,4 +601,10 @@
EXPORT_SYMBOL(wireless_send_event);
#endif /* CONFIG_NET_RADIO || CONFIG_NET_PCMCIA_RADIO */
+#ifdef CONFIG_NETSWAP
+EXPORT_SYMBOL(netswap_sock_count);
+EXPORT_SYMBOL(netswap_free_pages_min);
+EXPORT_SYMBOL(netswap_dropped);
+#endif
+
#endif /* CONFIG_NET */
diff -Nurb linux.orig/net/packet/af_packet.c linux/net/packet/af_packet.c
--- linux.orig/net/packet/af_packet.c 2003-10-14 04:09:35.000000000 -0400
+++ linux/net/packet/af_packet.c 2004-05-31 02:18:03.000000000 -0400
@@ -449,6 +449,12 @@
snaplen = res;
}
#endif /* CONFIG_FILTER */
+#ifdef CONFIG_NETSWAP
+ /* packet doesn't use sock_queue_rcv_skb() ... */
+ /* an inline function defined in net/netswapping.h */
+ if (netswap_low_memory(sk, skb))
+ goto drop_n_restore;
+#endif /* CONFIG_NETSWAP */
if (atomic_read(&sk->rmem_alloc) + skb->truesize >= (unsigned)sk->rcvbuf)
goto drop_n_acct;
@@ -496,7 +502,7 @@
po->stats.tp_drops++;
spin_unlock(&sk->receive_queue.lock);
-#ifdef CONFIG_FILTER
+#if defined(CONFIG_FILTER) || defined(CONFIG_NETSWAP)
drop_n_restore:
#endif
if (skb_head != skb->data && skb_shared(skb)) {
@@ -557,6 +563,12 @@
snaplen = res;
}
#endif
+#ifdef CONFIG_NETSWAP
+ /* packet doesn't use sock_queue_rcv_skb() ... */
+ /* an inline function defined in net/netswapping.h */
+ if (netswap_low_memory(sk, skb))
+ goto drop_n_restore;
+#endif /* CONFIG_NETSWAP */
if (sk->type == SOCK_DGRAM) {
macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16;
diff -Nurb linux.orig/net/sunrpc/sched.c linux/net/sunrpc/sched.c
--- linux.orig/net/sunrpc/sched.c 2003-07-04 04:12:33.000000000 -0400
+++ linux/net/sunrpc/sched.c 2004-05-31 02:18:03.000000000 -0400
@@ -79,10 +79,11 @@
*/
static spinlock_t rpc_sched_lock = SPIN_LOCK_UNLOCKED;
+#if CONFIG_SWAP_VIA_NFS || CONFIG_SWAP_VIA_NFS_MODULE
/*
* This is the last-ditch buffer for NFS swap requests
*/
-static u32 swap_buffer[PAGE_SIZE >> 2];
+static u32 swap_buffer[2*PAGE_SIZE >> 2];
static long swap_buffer_used;
/*
@@ -96,6 +97,7 @@
{
clear_bit(1, &swap_buffer_used);
}
+#endif
/*
* Disable the timer for a given RPC task. Should be called with
@@ -501,6 +503,7 @@
__rpc_execute(struct rpc_task *task)
{
int status = 0;
+ unsigned long alloc_flag = current->flags & PF_MEMALLOC;
dprintk("RPC: %4d rpc_execute flgs %x\n",
task->tk_pid, task->tk_flags);
@@ -510,6 +513,13 @@
return 0;
}
+ if (task->tk_flags & RPC_TASK_SWAPPER) {
+ if (!current->flags & PF_MEMALLOC) {
+ dprintk("__rpc_execute: Setting PF_MEMALLOC\n");
+ }
+ current->flags |= PF_MEMALLOC;
+ }
+
restarted:
while (1) {
/*
@@ -554,7 +564,8 @@
rpc_set_sleeping(task);
if (RPC_IS_ASYNC(task)) {
spin_unlock_bh(&rpc_queue_lock);
- return 0;
+ status = 0;
+ goto out;
}
}
spin_unlock_bh(&rpc_queue_lock);
@@ -563,7 +574,12 @@
/* sync task: sleep here */
dprintk("RPC: %4d sync task going to sleep\n",
task->tk_pid);
- if (current->pid == rpciod_pid)
+ /* it's ok to wait for rpciod when swapping,
+ * because this means it needed memory and is
+ * doing the swap-out itself.
+ */
+ if (current->pid == rpciod_pid &&
+ !(task->tk_flags & RPC_TASK_SWAPPER))
printk(KERN_ERR "RPC: rpciod waiting on sync task!\n");
__wait_event(task->tk_wait, !RPC_IS_SLEEPING(task));
@@ -608,6 +624,10 @@
/* Release all resources associated with the task */
rpc_release_task(task);
+ out:
+ if (!alloc_flag) {
+ current->flags &= ~PF_MEMALLOC;
+ }
return status;
}
@@ -699,10 +719,16 @@
{
u32 *buffer;
int gfp;
+ unsigned long alloc_flag = current->flags & PF_MEMALLOC;
+ void *ret = NULL;
- if (flags & RPC_TASK_SWAPPER)
+ if (flags & RPC_TASK_SWAPPER) {
gfp = GFP_ATOMIC;
- else if (flags & RPC_TASK_ASYNC)
+ if (!(current->flags & PF_MEMALLOC)) {
+ dprintk("rpc_allocate: Setting PF_MEMALLOC\n");
+ }
+ current->flags |= PF_MEMALLOC;
+ } else if (flags & RPC_TASK_ASYNC)
gfp = GFP_RPC;
else
gfp = GFP_KERNEL;
@@ -710,29 +736,44 @@
do {
if ((buffer = (u32 *) kmalloc(size, gfp)) != NULL) {
dprintk("RPC: allocated buffer %p\n", buffer);
- return buffer;
+ ret = buffer;
+ goto out;
}
+#if CONFIG_SWAP_VIA_NFS || CONFIG_SWAP_VIA_NFS_MODULE
if ((flags & RPC_TASK_SWAPPER) && size <= sizeof(swap_buffer)
&& rpc_lock_swapbuf()) {
dprintk("RPC: used last-ditch swap buffer\n");
- return swap_buffer;
+ ret = swap_buffer;
+ goto out;
+#endif
+ }
+ if (flags & RPC_TASK_ASYNC) {
+ ret = NULL;
+ goto out;
}
- if (flags & RPC_TASK_ASYNC)
- return NULL;
yield();
} while (!signalled());
- return NULL;
+ out:
+ if (!alloc_flag) {
+ current->flags &= ~PF_MEMALLOC;
+ }
+ return ret;
}
void
rpc_free(void *buffer)
{
+#if CONFIG_SWAP_VIA_NFS || CONFIG_SWAP_VIA_NFS_MODULE
if (buffer != swap_buffer) {
+#endif
kfree(buffer);
return;
+#if CONFIG_SWAP_VIA_NFS || CONFIG_SWAP_VIA_NFS_MODULE
}
rpc_unlock_swapbuf();
+ printk("RPC: Released swap buffer\n");
+#endif
}
/*
diff -Nurb linux.orig/net/sunrpc/xprt.c linux/net/sunrpc/xprt.c
--- linux.orig/net/sunrpc/xprt.c 2003-07-04 04:12:33.000000000 -0400
+++ linux/net/sunrpc/xprt.c 2004-05-31 02:18:03.000000000 -0400
@@ -139,7 +139,7 @@
__xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
{
if (!xprt->snd_task) {
- if (xprt->nocong || __xprt_get_cong(xprt, task))
+ if (__xprt_get_cong(xprt, task))
xprt->snd_task = task;
}
if (xprt->snd_task != task) {
@@ -179,7 +179,7 @@
if (!task)
return;
}
- if (xprt->nocong || __xprt_get_cong(xprt, task))
+ if (__xprt_get_cong(xprt, task))
xprt->snd_task = task;
}
@@ -276,6 +276,9 @@
{
struct rpc_rqst *req = task->tk_rqstp;
+ if (xprt->nocong || RPC_IS_SWAPPER(task))
+ return 1;
+
if (req->rq_cong)
return 1;
dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n",