mirror of
https://github.com/schoebel/mars
synced 2024-12-14 10:45:51 +00:00
c411a6f243
side effect / regression from 814b92ba19
292 lines
6.4 KiB
C
292 lines
6.4 KiB
C
// (c) 2012 Thomas Schoebel-Theuer / 1&1 Internet AG
|
|
|
|
#include "lib_mapfree.h"
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/list.h>
|
|
#include <linux/types.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/file.h>
|
|
|
|
int mapfree_period_sec = 10;
|
|
EXPORT_SYMBOL_GPL(mapfree_period_sec);
|
|
|
|
static
|
|
DECLARE_RWSEM(mapfree_mutex);
|
|
|
|
static
|
|
LIST_HEAD(mapfree_list);
|
|
|
|
static
|
|
void mapfree_pages(struct mapfree_info *mf, bool force)
|
|
{
|
|
struct address_space *mapping;
|
|
pgoff_t start;
|
|
pgoff_t end;
|
|
|
|
if (unlikely(!mf->mf_filp || !(mapping = mf->mf_filp->f_mapping)))
|
|
goto done;
|
|
|
|
if (force) {
|
|
start = 0;
|
|
end = -1;
|
|
} else {
|
|
unsigned long flags;
|
|
loff_t tmp;
|
|
loff_t min;
|
|
|
|
traced_lock(&mf->mf_lock, flags);
|
|
|
|
min = tmp = mf->mf_min[0];
|
|
if (likely(mf->mf_min[1] < min))
|
|
min = mf->mf_min[1];
|
|
if (tmp) {
|
|
mf->mf_min[1] = tmp;
|
|
mf->mf_min[0] = 0;
|
|
}
|
|
|
|
traced_unlock(&mf->mf_lock, flags);
|
|
|
|
if (min || mf->mf_last) {
|
|
start = mf->mf_last / PAGE_SIZE;
|
|
mf->mf_last = min;
|
|
end = min / PAGE_SIZE;
|
|
} else { // there was no progress for at least 2 rounds
|
|
start = 0;
|
|
end = -1;
|
|
}
|
|
|
|
MARS_DBG("file = '%s' start = %lu end = %lu\n", SAFE_STR(mf->mf_name), start, end);
|
|
}
|
|
|
|
if (end >= start || end == -1) {
|
|
invalidate_mapping_pages(mapping, start, end);
|
|
}
|
|
|
|
done:;
|
|
}
|
|
|
|
static
|
|
void _mapfree_put(struct mapfree_info *mf)
|
|
{
|
|
if (atomic_dec_and_test(&mf->mf_count)) {
|
|
MARS_DBG("closing file '%s' filp = %p\n", mf->mf_name, mf->mf_filp);
|
|
list_del_init(&mf->mf_head);
|
|
if (likely(mf->mf_filp)) {
|
|
mapfree_pages(mf, true);
|
|
filp_close(mf->mf_filp, NULL);
|
|
}
|
|
brick_string_free(mf->mf_name);
|
|
brick_mem_free(mf);
|
|
}
|
|
}
|
|
|
|
void mapfree_put(struct mapfree_info *mf)
|
|
{
|
|
down_write(&mapfree_mutex);
|
|
_mapfree_put(mf);
|
|
up_write(&mapfree_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mapfree_put);
|
|
|
|
struct mapfree_info *mapfree_get(const char *name, int flags)
|
|
{
|
|
struct mapfree_info *mf = NULL;
|
|
struct list_head *tmp;
|
|
|
|
if (!(flags & O_DIRECT)) {
|
|
down_read(&mapfree_mutex);
|
|
for (tmp = mapfree_list.next; tmp != &mapfree_list; tmp = tmp->next) {
|
|
struct mapfree_info *_mf = container_of(tmp, struct mapfree_info, mf_head);
|
|
if (_mf->mf_flags == flags && !strcmp(_mf->mf_name, name)) {
|
|
mf = _mf;
|
|
atomic_inc(&mf->mf_count);
|
|
break;
|
|
}
|
|
}
|
|
up_read(&mapfree_mutex);
|
|
|
|
if (mf)
|
|
goto done;
|
|
}
|
|
|
|
for (;;) {
|
|
struct address_space *mapping;
|
|
struct inode *inode;
|
|
int ra = 1;
|
|
int prot = 0600;
|
|
mm_segment_t oldfs;
|
|
|
|
mf = brick_zmem_alloc(sizeof(struct mapfree_info));
|
|
if (unlikely(!mf)) {
|
|
MARS_ERR("no mem, name = '%s'\n", name);
|
|
continue;
|
|
}
|
|
|
|
mf->mf_name = brick_strdup(name);
|
|
if (unlikely(!mf->mf_name)) {
|
|
MARS_ERR("no mem, name = '%s'\n", name);
|
|
brick_mem_free(mf);
|
|
continue;
|
|
}
|
|
|
|
mf->mf_flags = flags;
|
|
INIT_LIST_HEAD(&mf->mf_head);
|
|
atomic_set(&mf->mf_count, 1);
|
|
spin_lock_init(&mf->mf_lock);
|
|
mf->mf_max = -1;
|
|
|
|
oldfs = get_fs();
|
|
set_fs(get_ds());
|
|
mf->mf_filp = filp_open(name, flags, prot);
|
|
set_fs(oldfs);
|
|
|
|
MARS_DBG("file '%s' flags = %d prot = %d filp = %p\n", name, flags, prot, mf->mf_filp);
|
|
|
|
if (unlikely(!mf->mf_filp || IS_ERR(mf->mf_filp))) {
|
|
int err = PTR_ERR(mf->mf_filp);
|
|
MARS_ERR("can't open file '%s' status=%d\n", name, err);
|
|
mf->mf_filp = NULL;
|
|
_mapfree_put(mf);
|
|
mf = NULL;
|
|
break;
|
|
}
|
|
|
|
if (unlikely(!(mapping = mf->mf_filp->f_mapping) ||
|
|
!(inode = mapping->host))) {
|
|
MARS_ERR("file '%s' has no mapping\n", name);
|
|
mf->mf_filp = NULL;
|
|
_mapfree_put(mf);
|
|
mf = NULL;
|
|
break;
|
|
}
|
|
|
|
mapping_set_gfp_mask(mapping, mapping_gfp_mask(mapping) & ~(__GFP_IO | __GFP_FS));
|
|
|
|
mf->mf_max = i_size_read(inode);
|
|
|
|
if (S_ISBLK(inode->i_mode)) {
|
|
MARS_INF("changing blkdev readahead from %lu to %d\n", inode->i_bdev->bd_disk->queue->backing_dev_info.ra_pages, ra);
|
|
inode->i_bdev->bd_disk->queue->backing_dev_info.ra_pages = ra;
|
|
}
|
|
|
|
if (flags & O_DIRECT) { // never share them
|
|
break;
|
|
}
|
|
|
|
// maintain global list of all open files
|
|
down_write(&mapfree_mutex);
|
|
for (tmp = mapfree_list.next; tmp != &mapfree_list; tmp = tmp->next) {
|
|
struct mapfree_info *_mf = container_of(tmp, struct mapfree_info, mf_head);
|
|
if (unlikely(_mf->mf_flags == flags && !strcmp(_mf->mf_name, name))) {
|
|
MARS_WRN("race on creation of '%s' detected\n", name);
|
|
_mapfree_put(mf);
|
|
mf = _mf;
|
|
goto leave;
|
|
}
|
|
}
|
|
list_add_tail(&mf->mf_head, &mapfree_list);
|
|
leave:
|
|
up_write(&mapfree_mutex);
|
|
break;
|
|
}
|
|
done:
|
|
return mf;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mapfree_get);
|
|
|
|
void mapfree_set(struct mapfree_info *mf, loff_t min, loff_t max)
|
|
{
|
|
unsigned long flags;
|
|
|
|
traced_lock(&mf->mf_lock, flags);
|
|
if (!mf->mf_min[0] || mf->mf_min[0] > min)
|
|
mf->mf_min[0] = min;
|
|
if (max >= 0 && mf->mf_max < max)
|
|
mf->mf_max = max;
|
|
traced_unlock(&mf->mf_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mapfree_set);
|
|
|
|
static
|
|
int mapfree_thread(void *data)
|
|
{
|
|
while (!brick_thread_should_stop()) {
|
|
struct mapfree_info *mf = NULL;
|
|
struct list_head *tmp;
|
|
long long eldest = 0;
|
|
|
|
brick_msleep(500);
|
|
|
|
if (mapfree_period_sec <= 0)
|
|
continue;
|
|
|
|
down_read(&mapfree_mutex);
|
|
|
|
for (tmp = mapfree_list.next; tmp != &mapfree_list; tmp = tmp->next) {
|
|
struct mapfree_info *_mf = container_of(tmp, struct mapfree_info, mf_head);
|
|
if (unlikely(!_mf->mf_jiffies)) {
|
|
_mf->mf_jiffies = jiffies;
|
|
continue;
|
|
}
|
|
if ((long long)jiffies - _mf->mf_jiffies > mapfree_period_sec * HZ &&
|
|
(!mf || _mf->mf_jiffies < eldest)) {
|
|
mf = _mf;
|
|
eldest = _mf->mf_jiffies;
|
|
}
|
|
}
|
|
if (mf)
|
|
atomic_inc(&mf->mf_count);
|
|
|
|
up_read(&mapfree_mutex);
|
|
|
|
if (!mf) {
|
|
continue;
|
|
}
|
|
|
|
mapfree_pages(mf, false);
|
|
|
|
mf->mf_jiffies = jiffies;
|
|
mapfree_put(mf);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
////////////////// module init stuff /////////////////////////
|
|
|
|
static
|
|
struct task_struct *mf_thread = NULL;
|
|
|
|
int __init init_mars_mapfree(void)
|
|
{
|
|
MARS_DBG("init_mapfree()\n");
|
|
mf_thread = brick_thread_create(mapfree_thread, NULL, "mars_mapfree");
|
|
if (unlikely(!mf_thread)) {
|
|
MARS_ERR("could not create mapfree thread\n");
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void __exit exit_mars_mapfree(void)
|
|
{
|
|
MARS_DBG("exit_mapfree()\n");
|
|
if (likely(mf_thread)) {
|
|
brick_thread_stop(mf_thread);
|
|
mf_thread = NULL;
|
|
}
|
|
}
|
|
|
|
#ifndef CONFIG_MARS_HAVE_BIGMODULE
|
|
MODULE_DESCRIPTION("MARS mapfree infrastructure");
|
|
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(init_mars_mapfree);
|
|
module_exit(exit_mars_mapfree);
|
|
#endif
|