Add mmap tests.

Two test programs are added. The run time is about 1min on my el7
instance.

The test script finishes up with a read/write mmap test on offline
extents to verify the data wait paths in those functions.

One program will perform vfs read/write and mmap read/write calls on
the same file from across 5 threads (mounts) repeatedly.  The goal
is to assure there are no locking issues between read/write paths.

The second test program performs consistency checking on a file that is
repeatedly written/read using memory maps and normal reads and writes,
and the content is verified after every operation.

Signed-off-by: Auke Kok <auke.kok@versity.com>

tests/.gitignore

@@ -10,3 +10,5 @@ src/stage_tmpfile
 src/create_xattr_loop
 src/o_tmpfile_umask
 src/o_tmpfile_linkat
+src/mmap_stress
+src/mmap_validate

tests/Makefile

@@ -13,7 +13,9 @@ BIN := src/createmany			\
 	src/create_xattr_loop		\
 	src/fragmented_data_extents	\
 	src/o_tmpfile_umask		\
-	src/o_tmpfile_linkat
+	src/o_tmpfile_linkat		\
+	src/mmap_stress			\
+	src/mmap_validate
 
 DEPS := $(wildcard src/*.d)
 
@@ -23,8 +25,10 @@ ifneq ($(DEPS),)
 -include $(DEPS)
 endif
 
+src/mmap_stress: LIBS+=-lpthread
+
 $(BIN): %: %.c Makefile
-	gcc $(CFLAGS) -MD -MP -MF $*.d $< -o $@
+	gcc $(CFLAGS) -MD -MP -MF $*.d $< -o $@ $(LIBS)
 
 .PHONY: clean
 clean:

tests/golden/mmap

@@ -0,0 +1,27 @@
+== mmap_stress
+thread 0 complete
+thread 1 complete
+thread 2 complete
+thread 3 complete
+thread 4 complete
+== basic mmap/read/write consistency checks
+== mmap read from offline extent
+0: offset: 0 length: 2 flags: O.L
+extents: 1
+1
+00000200:  ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea  ................
+0
+0: offset: 0 length: 2 flags: ..L
+extents: 1
+== mmap write to an offline extent
+0: offset: 0 length: 2 flags: O.L
+extents: 1
+1
+0
+0: offset: 0 length: 2 flags: ..L
+extents: 1
+00000000  ea ea ea ea ea ea ea ea  ea ea ea ea ea ea ea ea  |................|
+00000010  11 11 11 11 11 11 11 11  11 11 11 11 11 11 11 11  |................|
+00000020  ea ea ea ea ea ea ea ea  ea ea ea ea ea ea ea ea  |................|
+00000030
+== done

tests/sequence

@@ -17,6 +17,7 @@ projects.sh
 large-fragmented-free.sh
 format-version-forward-back.sh
 enospc.sh
+mmap.sh
 srch-safe-merge-pos.sh
 srch-basic-functionality.sh
 simple-xattr-unit.sh

tests/src/mmap_stress.c

@@ -0,0 +1,181 @@
+#define _GNU_SOURCE
+/*
+ * mmap() stress test for scoutfs
+ *
+ * This test exercises the scoutfs kernel module's locking by
+ * repeatedly reading/writing using mmap and pread/write calls
+ * across 5 clients (mounts).
+ *
+ * Each thread operates on a single thread/client, and performs
+ * operations in a random order on the file.
+ *
+ * The goal is to assure that locking between _page_mkwrite vfs
+ * calls and the normal read/write paths do not cause deadlocks.
+ *
+ * There is no content validation performed. All that is done is
+ * assure that the programs continues without errors.
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+#include <pthread.h>
+#include <errno.h>
+
+static int size = 0;
+static int count = 0; /* XXX make this duration instead */
+
+struct thread_info {
+	int nr;
+	int fd;
+};
+
+static void *run_test_func(void *ptr)
+{
+	void *buf = NULL;
+	char *addr = NULL;
+	struct thread_info *tinfo = ptr;
+	int c = 0;
+	int fd;
+	ssize_t read, written, ret;
+	int preads = 0, pwrites = 0, mreads = 0, mwrites = 0;
+
+	fd = tinfo->fd;
+
+	if (posix_memalign(&buf, 4096, size) != 0) {
+		perror("calloc");
+		exit(-1);
+	}
+
+	addr = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED) {
+		perror("mmap");
+		exit(-1);
+	}
+
+	usleep(100000); /* 0.1sec to allow all threads to start roughly at the same time */
+
+	for (;;) {
+		if (++c > count)
+			break;
+
+		switch (rand() % 4) {
+		case 0: /* pread */
+			preads++;
+			for (read = 0; read < size;) {
+				ret = pread(fd, buf, size - read, read);
+				if (ret < 0) {
+					perror("pwrite");
+					exit(-1);
+				}
+				read += ret;
+			}
+			break;
+		case 1: /* pwrite */
+			pwrites++;
+			memset(buf, (char)(c & 0xff), size);
+			for (written = 0; written < size;) {
+				ret = pwrite(fd, buf, size - written, written);
+				if (ret < 0) {
+					perror("pwrite");
+					exit(-1);
+				}
+				written += ret;
+			}
+			break;
+		case 2: /* mmap read */
+			mreads++;
+			memcpy(buf, addr, size); /* noerr */
+			break;
+		case 3: /* mmap write */
+			mwrites++;
+			memset(buf, (char)(c & 0xff), size);
+			memcpy(addr, buf, size); /* noerr */
+			break;
+		}
+	}
+
+	munmap(addr, size);
+
+	free(buf);
+
+	printf("thread %u complete: preads %u pwrites %u mreads %u mwrites %u\n", tinfo->nr,
+		mreads, mwrites, preads, pwrites);
+
+	return NULL;
+}
+
+int main(int argc, char **argv)
+{
+	pthread_t thread[5];
+	struct thread_info tinfo[5];
+	int fd[5];
+	int ret;
+	int i;
+
+	if (argc != 8) {
+		fprintf(stderr, "%s requires 7 arguments - size count file1 file2 file3 file4 file5\n", argv[0]);
+		exit(-1);
+	}
+
+	size = atoi(argv[1]);
+	if (size <= 0) {
+		fprintf(stderr, "invalid size, must be greater than 0\n");
+		exit(-1);
+	}
+
+	count = atoi(argv[2]);
+	if (count < 0) {
+		fprintf(stderr, "invalid count, must be greater than 0\n");
+		exit(-1);
+	}
+
+	/* create and truncate one fd */
+	fd[0] = open(argv[3], O_RDWR | O_CREAT | O_TRUNC, 00644);
+	if (fd[0] < 0) {
+		perror("open");
+		exit(-1);
+	}
+
+	/* make it the test size */
+	if (posix_fallocate(fd[0], 0, size) != 0) {
+		perror("fallocate");
+		exit(-1);
+	}
+
+	/* now open the rest of the fds */
+	for (i = 1; i < 5; i++) {
+		fd[i] = open(argv[3+i], O_RDWR);
+		if (fd[i] < 0) {
+			perror("open");
+			exit(-1);
+		}
+	}
+
+	/* start threads */
+	for (i = 0; i < 5; i++) {
+		tinfo[i].fd = fd[i];
+		tinfo[i].nr = i;
+		ret = pthread_create(&thread[i], NULL, run_test_func, (void*)&tinfo[i]);
+
+		if (ret) {
+			perror("pthread_create");
+			exit(-1);
+		}
+	}
+
+	/* wait for complete */
+	for (i = 0; i < 5; i++)
+		pthread_join(thread[i], NULL);
+
+	for (i = 0; i < 5; i++)
+		close(fd[i]);
+
+	exit(0);
+}

tests/src/mmap_validate.c

@@ -0,0 +1,159 @@
+#define _GNU_SOURCE
+/*
+ * mmap() content consistency checking for scoutfs
+ *
+ * This test program validates that content from memory mappings
+ * are consistent across clients, whether written/read with mmap or
+ * normal writes/reads.
+ *
+ * One side of (read/write) will always be memory mapped. It may
+ * be that both sides do memory mapped (33% of the time).
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <errno.h>
+
+static int count = 0;
+static int size = 0;
+
+static void run_test_func(int fd1, int fd2)
+{
+	void *buf1 = NULL;
+	void *buf2 = NULL;
+	char *addr1 = NULL;
+	char *addr2 = NULL;
+	int c = 0;
+	ssize_t read, written, ret;
+
+	/* buffers for both sides to compare */
+	if (posix_memalign(&buf1, 4096, size) != 0) {
+		perror("calloc1");
+		exit(-1);
+	}
+
+	if (posix_memalign(&buf2, 4096, size) != 0) {
+		perror("calloc1");
+		exit(-1);
+	}
+
+	/* memory maps for both sides */
+	addr1 = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, fd1, 0);
+	if (addr1 == MAP_FAILED) {
+		perror("mmap1");
+		exit(-1);
+	}
+
+	addr2 = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, fd2, 0);
+	if (addr2 == MAP_FAILED) {
+		perror("mmap2");
+		exit(-1);
+	}
+
+	for (;;) {
+		if (++c > count) /* 10k iterations */
+			break;
+
+		/* put a pattern in buf1 */
+		memset(buf1, c & 0xff, size);
+
+		/* pwrite or mmap write from buf1 */
+		switch (c % 3) {
+		case 0:	/* pwrite */
+			for (written = 0; written < size;) {
+				ret = pwrite(fd1, buf1, size - written, written);
+				if (ret < 0) {
+					perror("pwrite");
+					exit(-1);
+				}
+				written += ret;
+			}
+			break;
+		default: /* mmap write */
+			memcpy(addr1, buf1, size);
+			break;
+		}
+
+		/* pread or mmap read to buf2 */
+		switch (c % 3) {
+		case 2: /* pread */
+			for (read = 0; read < size;) {
+				ret = pread(fd2, buf2, size - read, read);
+				if (ret < 0) {
+					perror("pwrite");
+					exit(-1);
+				}
+				read += ret;
+			}
+			break;
+		default: /* mmap read */
+			memcpy(buf2, addr2, size);
+			break;
+		}
+
+		/* compare bufs */
+		if (memcmp(buf1, buf2, size) != 0) {
+			fprintf(stderr, "memcmp() failed\n");
+			exit(-1);
+		}
+	}
+
+	munmap(addr1, size);
+	munmap(addr2, size);
+
+	free(buf1);
+	free(buf2);
+}
+
+int main(int argc, char **argv)
+{
+	int fd[1];
+
+	if (argc != 5) {
+		fprintf(stderr, "%s requires 4 arguments - size count file1 file2\n", argv[0]);
+		exit(-1);
+	}
+
+	size = atoi(argv[1]);
+	if (size <= 0) {
+		fprintf(stderr, "invalid size, must be greater than 0\n");
+		exit(-1);
+	}
+
+	count = atoi(argv[2]);
+	if (count < 3) {
+		fprintf(stderr, "invalid count, must be greater than 3\n");
+		exit(-1);
+	}
+
+	/* create and truncate one fd */
+	fd[0] = open(argv[3], O_RDWR | O_CREAT | O_TRUNC, 00644);
+	if (fd[0] < 0) {
+		perror("open");
+		exit(-1);
+	}
+
+	fd[1] = open(argv[4], O_RDWR , 00644);
+	if (fd[1] < 0) {
+		perror("open");
+		exit(-1);
+	}
+
+	/* make it the test size */
+	if (posix_fallocate(fd[0], 0, size) != 0) {
+		perror("fallocate");
+		exit(-1);
+	}
+
+	/* run the test function */
+	run_test_func(fd[0], fd[1]);
+
+	close(fd[0]);
+	close(fd[1]);
+
+	exit(0);
+}

tests/tests/mmap.sh

@@ -0,0 +1,54 @@
+#
+# test mmap() and normal read/write consistency between different nodes
+#
+
+t_require_commands mmap_stress mmap_validate scoutfs xfs_io
+
+echo "== mmap_stress"
+mmap_stress 8192 2000 "$T_D0/mmap_stress" "$T_D1/mmap_stress" "$T_D2/mmap_stress" "$T_D3/mmap_stress" "$T_D4/mmap_stress" | sed 's/:.*//g' | sort
+
+echo "== basic mmap/read/write consistency checks"
+mmap_validate 256 1000 "$T_D0/mmap_val1" "$T_D1/mmap_val1"
+mmap_validate 8192 1000 "$T_D0/mmap_val2" "$T_D1/mmap_val2"
+mmap_validate 88400 1000 "$T_D0/mmap_val3" "$T_D1/mmap_val3"
+
+echo "== mmap read from offline extent"
+F="$T_D0/mmap-offline"
+touch "$F"
+xfs_io -c "pwrite -S 0xEA 0 8192" "$F" > /dev/null
+cp "$F" "${F}-stage"
+vers=$(scoutfs stat -s data_version "$F")
+scoutfs release "$F" -V "$vers" -o 0 -l 8192
+scoutfs get-fiemap -L "$F"
+xfs_io -c "mmap -rwx 0 8192" \
+	-c "mread -v 512 16" "$F" &
+sleep 1
+# should be 1 - data waiting
+jobs | wc -l
+scoutfs stage "${F}-stage" "$F" -V "$vers" -o 0 -l 8192
+# xfs_io thread <here> will output 16 bytes of read data
+sleep 1
+# should be 0 - no more waiting jobs, xfs_io should have exited
+jobs | wc -l
+scoutfs get-fiemap -L "$F"
+
+echo "== mmap write to an offline extent"
+# reuse the same file
+scoutfs release "$F" -V "$vers" -o 0 -l 8192
+scoutfs get-fiemap -L "$F"
+xfs_io -c "mmap -rwx 0 8192" \
+	-c "mwrite -S 0x11 528 16" "$F" &
+sleep 1
+# should be 1 job waiting
+jobs | wc -l
+scoutfs stage "${F}-stage" "$F" -V "$vers" -o 0 -l 8192
+# no output here from write
+sleep 1
+# should be 0 - no more waiting jobs, xfs_io should have exited
+jobs | wc -l
+scoutfs get-fiemap -L "$F"
+# read back contents to assure write changed the file
+dd status=none if="$F" bs=1 count=48 skip=512 | hexdump -C
+
+echo "== done"
+t_pass