Attachment 239910 Details for Bug 269328 – Test program that triggers the error on the NFS client

Test program that triggers the error on the NFS client

fspace-and-mmap.c (text/plain), 3.72 KB, created by Alan Somers on 2023-02-04 22:02:18 UTC

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Creator: Alan Somers

Created: 2023-02-04 22:02:18 UTC

Size: 3.72 KB

patch

obsolete

>#include <sys/mman.h>
>#include <sys/param.h>
>#include <assert.h>
>#include <err.h>
>#include <fcntl.h>
>#include <malloc_np.h>
>#include <stdlib.h>
>#include <string.h>
>#include <strings.h>
>#include <unistd.h>
>
>
>off_t filesize = 0;
>int fd = -1;
>unsigned char *control_buf = NULL;
>const off_t MAX_FILESIZE = 0x100000;
>
>static void
>do_ftruncate(off_t offs)
>{
>	if (ftruncate(fd, offs) != 0)
>		err(1, "ftruncate");
>	filesize = offs;
>}
>
>static void
>do_fspacectl(ssize_t size, off_t offs)
>{
>	struct spacectl_range rqsr = {
>		.r_offset = offs,
>		.r_len = size,
>	};
>	struct spacectl_range rmsr;
>
>	if (0 != fspacectl(fd, SPACECTL_DEALLOC, &rqsr, 0, &rmsr))
>		err(1, "fspacectl");
>	assert(0 == rmsr.r_len);
>	assert(offs + size == rmsr.r_offset);
>	memset(control_buf + offs, 0, size);
>}
>
>static void
>do_mapread(ssize_t size, off_t offs)
>{
>	unsigned char *p;
>	off_t pg_offset, page_mask;
>	size_t map_size;
>	int i;
>
>	page_mask = getpagesize() - 1;
>	pg_offset = offs & page_mask;
>	map_size = pg_offset + size;
>
>	p = mmap(NULL, map_size, PROT_READ, MAP_FILE | MAP_SHARED, fd,
>	    offs - pg_offset);
>	if (p == MAP_FAILED)
>		err(1, "mmap");
>
>	for (i=0; i < size; i++) {
>		if (*(p + pg_offset + i) != *(control_buf + offs + i)) {
>			errx(1, "miscompare at offset %#lx.  "
>				"expected %#02x got %#02x",
>				offs + i,
>				*(control_buf + offs + i),
>				*(p + pg_offset + i));
>		}
>
>	}
>
>	if (munmap(p, map_size) != 0)
>		err(1, "munmap");
>}
>
>static void
>do_mapwrite(ssize_t size, off_t offs)
>{
>	char *buf;
>	void *p;
>	off_t pg_offset, page_mask;
>	size_t map_size;
>	long i;
>
>	assert(offs + size <= MAX_FILESIZE);
>
>	page_mask = getpagesize() - 1;
>	pg_offset = offs & page_mask;
>	map_size = pg_offset + size;
>
>	buf = (char*)malloc(size);
>	if (buf == NULL)
>		err(1, "malloc");
>	for (i=0; i < size; i++)
>		buf[i] = random();
>
>	if (offs + size > filesize) {
>		/* 
>		 * Must manually extend.  vm_mmap_vnode will not implicitly
>		 * extend a vnode
>		 */
>		do_ftruncate(offs + size);
>	}
>
>	p = mmap(NULL, map_size, PROT_READ | PROT_WRITE,
>	    MAP_FILE | MAP_SHARED, fd, offs - pg_offset);
>	if (p == MAP_FAILED)
>		err(1, "mmap");
>
>	bcopy(buf, (char*)p + pg_offset, size);
>	bcopy(buf, control_buf + offs, size);
>
>	free(buf);
>	// Uncomment to enable msync, which masks the bug
>	/*if (msync(p, map_size, MS_SYNC) != 0) err(1, "msync");*/
>	if (munmap(p, map_size) != 0)
>		err(1, "munmap");
>}
>
>void do_write(ssize_t size, off_t offs)
>{
>	long i;
>
>	for (i=0; i < size; i++)
>		control_buf[offs + i] = random();
>
>	if (pwrite(fd, control_buf + offs, size, offs ) != size)
>		err(1, "pwrite");
>	filesize = MAX(filesize, offs + size);
>}
>
>
>int main(int argc, char **argv) {
>	const char *filename;
>
>	if (argc != 2) {
>		errx(1, "usage: %s <FILENAME>", argv[0]);
>	}
>
>	filename = argv[1];
>
>	fd = open(filename, O_CREAT | O_RDWR | O_TRUNC, 0644);
>	if (fd < 0)
>		err(1, "open");
>
>	srandom(12345);
>
>	control_buf = calloc(MAX_FILESIZE, 1);
>	if (control_buf == NULL)
>		err(1, "calloc");
>
>	/* 
>	 * These three operations suffice to produce miscompare on either
>	 * fusefs or UFS, albeit at different offsets.
>	 * ZFS, msdosfs, and tmpfs do not seem to be affected.
>	 * PR 269261 fixes it for UFS
>	 */
>	/*do_mapwrite(0xd052, 0xee29);*/
>	/*do_fspacectl(0x55b0, 0x16166);*/
>	/*do_mapread(0xea1f, 0xbb4e);*/
>
>	/* 
>	 * Alternate method also produces failure on fusefs:
>	 * mmapwrite, directwrite, mmapread 
>	 */
>	/*do_mapwrite(0xd052, 0xee29);*/
>	/*if (fcntl(fd, F_SETFL, O_DIRECT) != 0)*/
>		/*err(1, "fcntl");*/
>	/*do_write(0x55b0, 0x16166);*/
>	/*if (fcntl(fd, F_SETFL, 0) != 0)*/
>		/*err(1, "fcntl");*/
>	/*do_mapread(0xea1f, 0xbb4e);*/
>
>	/* This sequence produces a failure on NFS */
>	do_mapwrite(0x9708, 0xb65af);
>	do_fspacectl(0x5f4d6,0x492cd);
>	do_mapwrite(0x13a13, 0x775cb);
>	do_mapwrite(0x47c8, 0x40d57);
>	do_mapwrite(0x2c4b5, 0xd3b4b);
>	do_mapread( 0x5e5a7, 0x34ba5);
>}

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Attachments on bug 269328: 239910 | 239937 | 239981