minix/minix/tests/test72.c
David van Moolenbroek e321f65582 libfsdriver: support mmap on FSes with no device
This patch adds (very limited) support for memory-mapping pages on
file systems that are mounted on the special "none" device and that
do not implement PEEK support by themselves.  This includes hgfs,
vbfs, and procfs.

The solution is implemented in libvtreefs, and consists of allocating
pages, filling them with content by calling the file system's READ
functionality, passing the pages to VM, and freeing them again.  A new
VM flag is used to indicate that these pages should be mapped in only
once, and thus not cached beyond their single use.  This prevents
stale data from getting mapped in without the involvement of the file
system, which would be problematic on file systems where file contents
may become outdated at any time.  No VM caching means no sharing and
poor performance, but mmap no longer fails on these file systems.

Compared to a libc-based approach, this patch retains the on-demand
nature of mmap.  Especially tail(1) is known to map in a large file
area only to use a small portion of it.

All file systems now need to be given permission for the SETCACHEPAGE
and CLEARCACHE calls to VM.

A very basic regression test is added to test74.

Change-Id: I17afc4cb97315b515cad1542521b98f293b6b559
2014-11-15 11:19:52 +00:00

293 lines
5.5 KiB
C

/* Test 72 - libminixfs unit test.
*
* Exercise the caching functionality of libminixfs in isolation.
*/
#define _MINIX_SYSTEM
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/vm.h>
#include <minix/bdev.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/ioc_memory.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <math.h>
#include <minix/libminixfs.h>
int max_error = 0;
#include "common.h"
#include "testcache.h"
#define MYMAJOR 40 /* doesn't really matter, shouldn't be NO_DEV though */
#define MYDEV makedev(MYMAJOR, 1)
static int curblocksize = -1;
static char *writtenblocks[MAXBLOCKS];
/* Some functions used by testcache.c */
int
dowriteblock(int b, int blocksize, u32_t seed, char *data)
{
struct buf *bp;
assert(blocksize == curblocksize);
if(!(bp = lmfs_get_block(MYDEV, b, NORMAL))) {
e(30);
return 0;
}
memcpy(bp->data, data, blocksize);
lmfs_markdirty(bp);
lmfs_put_block(bp, FULL_DATA_BLOCK);
return blocksize;
}
int
readblock(int b, int blocksize, u32_t seed, char *data)
{
struct buf *bp;
assert(blocksize == curblocksize);
if(!(bp = lmfs_get_block(MYDEV, b, NORMAL))) {
e(30);
return 0;
}
memcpy(data, bp->data, blocksize);
lmfs_put_block(bp, FULL_DATA_BLOCK);
return blocksize;
}
void testend(void)
{
int i;
for(i = 0; i < MAXBLOCKS; i++) {
if(writtenblocks[i]) {
free(writtenblocks[i]);
writtenblocks[i] = NULL;
}
}
}
/* Fake some libminixfs client functions */
void
fs_blockstats(u64_t *total, u64_t *free, u64_t *used)
{
*total = *free = *used = 0;
}
static void allocate(int b)
{
assert(curblocksize > 0);
assert(!writtenblocks[b]);
if(!(writtenblocks[b] = calloc(1, curblocksize))) {
fprintf(stderr, "out of memory allocating block %d\n", b);
exit(1);
}
}
/* Fake some libblockdriver functions */
ssize_t
bdev_gather(dev_t dev, u64_t pos, iovec_t *vec, int count, int flags)
{
int i, block;
size_t size, block_off;
ssize_t tot = 0;
assert(dev == MYDEV);
assert(curblocksize > 0);
assert(!(pos % curblocksize));
for(i = 0; i < count; i++) {
char *data = (char *) vec[i].iov_addr;
block = pos / curblocksize;
block_off = (size_t)(pos % curblocksize);
size = vec[i].iov_size;
assert(size == PAGE_SIZE);
assert(block >= 0);
assert(block < MAXBLOCKS);
assert(block_off + size <= curblocksize);
if(!writtenblocks[block]) {
allocate(block);
}
memcpy(data, writtenblocks[block] + block_off, size);
pos += size;
tot += size;
}
return tot;
}
ssize_t
bdev_scatter(dev_t dev, u64_t pos, iovec_t *vec, int count, int flags)
{
int i, block;
size_t size, block_off;
ssize_t tot = 0;
assert(dev == MYDEV);
assert(curblocksize > 0);
assert(!(pos % curblocksize));
for(i = 0; i < count; i++) {
char *data = (char *) vec[i].iov_addr;
block = pos / curblocksize;
block_off = (size_t)(pos % curblocksize);
size = vec[i].iov_size;
assert(size == PAGE_SIZE);
assert(block >= 0);
assert(block < MAXBLOCKS);
assert(block_off + size <= curblocksize);
if(!writtenblocks[block]) {
allocate(block);
}
memcpy(writtenblocks[block] + block_off, data, size);
pos += size;
tot += size;
}
return tot;
}
ssize_t
bdev_read(dev_t dev, u64_t pos, char *data, size_t count, int flags)
{
int block;
assert(dev == MYDEV);
assert(curblocksize > 0);
assert(!(pos % curblocksize));
assert(count > 0);
assert(!(count % curblocksize));
assert(count == PAGE_SIZE);
assert(curblocksize == PAGE_SIZE);
block = pos / curblocksize;
assert(block >= 0);
assert(block < MAXBLOCKS);
if(!writtenblocks[block]) {
allocate(block);
}
memcpy(data, writtenblocks[block], curblocksize);
return count;
}
/* Fake some libsys functions */
__dead void
panic(const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
vfprintf(stderr, fmt, va);
va_end(va);
exit(1);
}
int
vm_info_stats(struct vm_stats_info *vsi)
{
return ENOSYS;
}
void
util_stacktrace(void)
{
fprintf(stderr, "fake stacktrace\n");
}
void *alloc_contig(size_t len, int flags, phys_bytes *phys)
{
return malloc(len);
}
int free_contig(void *addr, size_t len)
{
free(addr);
return 0;
}
u32_t sqrt_approx(u32_t v)
{
return (u32_t) sqrt(v);
}
int vm_set_cacheblock(void *block, dev_t dev, off_t dev_offset,
ino_t ino, off_t ino_offset, u32_t *flags, int blocksize, int setflags)
{
return ENOSYS;
}
void *vm_map_cacheblock(dev_t dev, off_t dev_offset,
ino_t ino, off_t ino_offset, u32_t *flags, int blocksize)
{
return MAP_FAILED;
}
int vm_clear_cache(dev_t dev)
{
return 0;
}
int
main(int argc, char *argv[])
{
size_t newblocksize;
int wss, cs, n = 0, p;
#define ITER 3
#define BLOCKS 200
start(72);
lmfs_setquiet(1);
/* Can the cache handle differently sized blocks? */
for(p = 1; p <= 3; p++) {
/* Do not update curblocksize until the cache is flushed. */
newblocksize = PAGE_SIZE*p;
lmfs_set_blocksize(newblocksize, MYMAJOR);
curblocksize = newblocksize; /* now it's safe to update */
lmfs_buf_pool(BLOCKS);
if(dotest(curblocksize, BLOCKS, ITER)) e(n);
n++;
}
/* Can the cache handle various combinations of the working set
* being larger and smaller than the cache?
*/
for(wss = 2; wss <= 3; wss++) {
int wsblocks = 10*wss*wss*wss*wss*wss;
for(cs = wsblocks/4; cs <= wsblocks*3; cs *= 1.5) {
lmfs_set_blocksize(PAGE_SIZE, MYMAJOR);
curblocksize = PAGE_SIZE; /* same as above */
lmfs_buf_pool(cs);
if(dotest(curblocksize, wsblocks, ITER)) e(n);
n++;
}
}
quit();
return 0;
}