e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include <errno.h>

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include <stdlib.h>

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include <sys/mman.h>

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include "alloc-util.h"

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering#include "fd-util.h"

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering#include "hashmap.h"

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering#include "list.h"

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include "log.h"

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include "macro.h"

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include "mmap-cache.h"

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#include "sigbus.h"

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering#include "util.h"

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersentypedef struct Window Window;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersentypedef struct Context Context;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersentypedef struct FileDescriptor FileDescriptor;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstruct Window {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *cache;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool invalidated:1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool keep_always:1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool in_unused:1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int prot;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen void *ptr;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t offset;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen size_t size;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen FileDescriptor *fd;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_FIELDS(Window, by_fd);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_FIELDS(Window, unused);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_HEAD(Context, contexts);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen};

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstruct Context {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *cache;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned id;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *window;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_FIELDS(Context, by_window);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen};

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstruct FileDescriptor {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *cache;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int fd;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool sigbus;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_HEAD(Window, windows);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen};

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstruct MMapCache {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int n_ref;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned n_windows;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned n_hit, n_missed;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Hashmap *fds;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *contexts[MMAP_CACHE_MAX_CONTEXTS];

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_HEAD(Window, unused);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *last_unused;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen};

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#define WINDOWS_MIN 64

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#ifdef ENABLE_DEBUG_MMAP_CACHE

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen# define WINDOW_SIZE (page_size())

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#else

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen# define WINDOW_SIZE (8ULL*1024ULL*1024ULL)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#endif

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom GundersenMMapCache* mmap_cache_new(void) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m = new0(MMapCache, 1);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!m)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m->n_ref = 1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom GundersenMMapCache* mmap_cache_ref(MMapCache *m) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m->n_ref > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m->n_ref ++;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void window_unlink(Window *w) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->ptr)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen munmap(w->ptr, w->size);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->fd)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_REMOVE(by_fd, w->fd->windows, w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->in_unused) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->cache->last_unused == w)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->cache->last_unused = w->unused_prev;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_REMOVE(unused, w->cache->unused, w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_FOREACH(by_window, c, w->contexts) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c->window == w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->window = NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void window_invalidate(Window *w) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->invalidated)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Replace the window with anonymous pages. This is useful

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert_se(mmap(w->ptr, w->size, w->prot, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0) == w->ptr);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->invalidated = true;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void window_free(Window *w) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_unlink(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->cache->n_windows--;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen free(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen_pure_ static bool window_matches(Window *w, int fd, int prot, uint64_t offset, size_t size) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(fd >= 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(size > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->fd &&

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen fd == w->fd->fd &&

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen prot == w->prot &&

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen offset >= w->offset &&

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen offset + size <= w->offset + w->size;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic Window *window_add(MMapCache *m) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!m->last_unused || m->n_windows <= WINDOWS_MIN) {

2237aa02f3e2739a1ebe9c0bc224b5125f5eb292David Herrmann

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Allocate a new window */

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w = new0(Window, 1);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!w)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m->n_windows++;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen } else {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Reuse an existing one */

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w = m->last_unused;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_unlink(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen zero(*w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->cache = m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void context_detach_window(Context *c) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c->window)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w = c->window;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->window = NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_REMOVE(by_window, w->contexts, c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!w->contexts && !w->keep_always) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Not used anymore? */

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#ifdef ENABLE_DEBUG_MMAP_CACHE

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Unmap unused windows immediately to expose use-after-unmap

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_free(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#else

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_PREPEND(unused, c->cache->unused, w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c->cache->last_unused)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->cache->last_unused = w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->in_unused = true;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen#endif

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void context_attach_window(Context *c, Window *w) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (c->window == w)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen context_detach_window(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (w->in_unused) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Used again? */

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_REMOVE(unused, c->cache->unused, w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (c->cache->last_unused == w)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->cache->last_unused = w->unused_prev;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->in_unused = false;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->window = w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_PREPEND(by_window, w->contexts, c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic Context *context_add(MMapCache *m, unsigned id) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c = m->contexts[id];

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (c)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c = new0(Context, 1);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->cache = m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->id = id;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(!m->contexts[id]);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m->contexts[id] = c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void context_free(Context *c) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen context_detach_window(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (c->cache) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c->cache->contexts[c->id] == c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->cache->contexts[c->id] = NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen free(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void fd_free(FileDescriptor *f) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(f);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen while (f->windows)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_free(f->windows);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (f->cache)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert_se(hashmap_remove(f->cache->fds, FD_TO_PTR(f->fd)));

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen free(f);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic FileDescriptor* fd_add(MMapCache *m, int fd) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen FileDescriptor *f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int r;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(fd >= 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen f = hashmap_get(m->fds, FD_TO_PTR(fd));

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (f)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen r = hashmap_ensure_allocated(&m->fds, NULL);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (r < 0)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen f = new0(FileDescriptor, 1);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!f)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen f->cache = m;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen f->fd = fd;

2237aa02f3e2739a1ebe9c0bc224b5125f5eb292David Herrmann

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen r = hashmap_put(m->fds, FD_TO_PTR(fd), f);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (r < 0) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen free(f);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic void mmap_cache_free(MMapCache *m) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen FileDescriptor *f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int i;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen for (i = 0; i < MMAP_CACHE_MAX_CONTEXTS; i++)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (m->contexts[i])

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen context_free(m->contexts[i]);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen while ((f = hashmap_first(m->fds)))

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen fd_free(f);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen hashmap_free(m->fds);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen while (m->unused)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_free(m->unused);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen free(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

2237aa02f3e2739a1ebe9c0bc224b5125f5eb292David Herrmann

e3dca0089b7b50e2ec21409d1292727921d06102Tom GundersenMMapCache* mmap_cache_unref(MMapCache *m) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!m)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m->n_ref > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen m->n_ref --;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (m->n_ref == 0)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen mmap_cache_free(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return NULL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic int make_room(MMapCache *m) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!m->last_unused)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen window_free(m->last_unused);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic int try_context(

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *m,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int fd,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int prot,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned context,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool keep_always,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t offset,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen size_t size,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen void **ret) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m->n_ref > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(fd >= 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(size > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(ret);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c = m->contexts[context];

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(c->id == context);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c->window)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!window_matches(c->window, fd, prot, offset, size)) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Drop the reference to the window, since it's unnecessary now */

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen context_detach_window(c);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (c->window->fd->sigbus)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -EIO;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c->window->keep_always = c->window->keep_always || keep_always;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic int find_mmap(

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *m,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int fd,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int prot,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned context,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool keep_always,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t offset,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen size_t size,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen void **ret) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen FileDescriptor *f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m->n_ref > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(fd >= 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(size > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen f = hashmap_get(m->fds, FD_TO_PTR(fd));

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!f)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(f->fd == fd);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (f->sigbus)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -EIO;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen LIST_FOREACH(by_fd, w, f->windows)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (window_matches(w, fd, prot, offset, size))

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen break;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!w)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c = context_add(m, context);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (!c)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -ENOMEM;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen context_attach_window(c, w);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen w->keep_always = w->keep_always || keep_always;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen *ret = (uint8_t*) w->ptr + (offset - w->offset);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return 1;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen}

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersenstatic int add_mmap(

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen MMapCache *m,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int fd,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int prot,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen unsigned context,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen bool keep_always,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t offset,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen size_t size,

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen struct stat *st,

04c0136989b7eb896bfb0fb176e11233d69e1453Lennart Poettering void **ret) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t woffset, wsize;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Context *c;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen FileDescriptor *f;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen Window *w;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen void *d;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen int r;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(m->n_ref > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(fd >= 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(size > 0);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen assert(ret);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen woffset = offset & ~((uint64_t) page_size() - 1ULL);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen wsize = size + (offset - woffset);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen wsize = PAGE_ALIGN(wsize);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (wsize < WINDOW_SIZE) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen uint64_t delta;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen delta = PAGE_ALIGN((WINDOW_SIZE - wsize) / 2);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (delta > offset)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen woffset = 0;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen else

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen woffset -= delta;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen wsize = WINDOW_SIZE;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (st) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen /* Memory maps that are larger then the files

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (woffset >= (uint64_t) st->st_size)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -EADDRNOTAVAIL;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (woffset + wsize > (uint64_t) st->st_size)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen wsize = PAGE_ALIGN(st->st_size - woffset);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen for (;;) {

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen d = mmap(NULL, wsize, prot, MAP_SHARED, fd, woffset);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (d != MAP_FAILED)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen break;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (errno != ENOMEM)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -errno;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen r = make_room(m);

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (r < 0)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return r;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen if (r == 0)

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen return -ENOMEM;

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen }

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen

e3dca0089b7b50e2ec21409d1292727921d06102Tom Gundersen c = context_add(m, context);

if (!c)

goto outofmem;

f = fd_add(m, fd);

if (!f)

goto outofmem;

w = window_add(m);

if (!w)

goto outofmem;

w->keep_always = keep_always;

w->ptr = d;

w->offset = woffset;

w->prot = prot;

w->size = wsize;

w->fd = f;

LIST_PREPEND(by_fd, f->windows, w);

context_detach_window(c);

c->window = w;

LIST_PREPEND(by_window, w->contexts, c);

*ret = (uint8_t*) w->ptr + (offset - w->offset);

return 1;

outofmem:

munmap(d, wsize);

return -ENOMEM;

}

int mmap_cache_get(

MMapCache *m,

int fd,

int prot,

unsigned context,

bool keep_always,

uint64_t offset,

size_t size,

struct stat *st,

void **ret) {

int r;

assert(m);

assert(m->n_ref > 0);

assert(fd >= 0);

assert(size > 0);

assert(ret);

assert(context < MMAP_CACHE_MAX_CONTEXTS);

/* Check whether the current context is the right one already */

r = try_context(m, fd, prot, context, keep_always, offset, size, ret);

if (r != 0) {

m->n_hit ++;

return r;

}

/* Search for a matching mmap */

r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret);

if (r != 0) {

m->n_hit ++;

return r;

}

m->n_missed++;

/* Create a new mmap */

return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret);

}

unsigned mmap_cache_get_hit(MMapCache *m) {

assert(m);

return m->n_hit;

}

unsigned mmap_cache_get_missed(MMapCache *m) {

assert(m);

return m->n_missed;

}

static void mmap_cache_process_sigbus(MMapCache *m) {

bool found = false;

FileDescriptor *f;

Iterator i;

int r;

assert(m);

/* Iterate through all triggered pages and mark their files as

for (;;) {

bool ours;

void *addr;

r = sigbus_pop(&addr);

if (_likely_(r == 0))

break;

if (r < 0) {

log_error_errno(r, "SIGBUS handling failed: %m");

abort();

}

ours = false;

HASHMAP_FOREACH(f, m->fds, i) {

Window *w;

LIST_FOREACH(by_fd, w, f->windows) {

if ((uint8_t*) addr >= (uint8_t*) w->ptr &&

(uint8_t*) addr < (uint8_t*) w->ptr + w->size) {

found = ours = f->sigbus = true;

break;

}

}

if (ours)

break;

}

/* Didn't find a matching window, give up */

if (!ours) {

log_error("Unknown SIGBUS page, aborting.");

abort();

}

}

/* The list of triggered pages is now empty. Now, let's remap

if (_likely_(!found))

return;

HASHMAP_FOREACH(f, m->fds, i) {

Window *w;

if (!f->sigbus)

continue;

LIST_FOREACH(by_fd, w, f->windows)

window_invalidate(w);

}

}

bool mmap_cache_got_sigbus(MMapCache *m, int fd) {

FileDescriptor *f;

assert(m);

assert(fd >= 0);

mmap_cache_process_sigbus(m);

f = hashmap_get(m->fds, FD_TO_PTR(fd));

if (!f)

return false;

return f->sigbus;

}

void mmap_cache_close_fd(MMapCache *m, int fd) {

FileDescriptor *f;

assert(m);

assert(fd >= 0);

/* Make sure that any queued SIGBUS are first dispatched, so

mmap_cache_process_sigbus(m);

f = hashmap_get(m->fds, FD_TO_PTR(fd));

if (!f)

return;

fd_free(f);

}