xfstests: Introduce a new SEEK_DATA/SEEK_HOLE tester

src/seek_copy_tester.c new file +4 -0

+#include<stdio.h>
+#include<stdlib.h>
+#include<stdint.h>
+#include<stdarg.h>

src/seek_copy_tester.c new file +8 -0

+int
+full_write(int fd, const void *buf, size_t count)
+{
+	int ret = 0;
+	const char *ptr = (const char *) buf;
+
+	while (count>  0) {
+		ssize_t n = write(fd, ptr, count);

src/seek_copy_tester.c new file +7 -0

+
+		ptr += n;
+		count -= n;
+	}
+
+	return ret;
+}

src/seek_copy_tester.c new file +6 -0

+int
+create_data_and_holes(int fd, size_t nr_total_bytes, off_t start_offset,
+		      uint64_t nr_skip_bytes, uint64_t nr_data_bytes,
+		      int wrote_hole_at_eof)
+{
+	int ret = 0;

src/seek_copy_tester.c new file +4 -0

+		} while (data_len>  0);
+
+		off += (nr_skip_bytes + nr_data_bytes);
+		total -= off;

src/seek_copy_tester.c new file +34 -0

+
+/*
+ * Copy a data extent from source file to dest file.
+ * @data_off: data offset
+ * @hole_off: hole offset
+ * The length of this extent is (hole_off - data_off).
+ */
+int
+do_extent_copy(int src_fd, int dest_fd, off_t data_off, off_t hole_off)
+{
+	uint64_t len = (uint64_t)(hole_off - data_off);
+	char buf[BUF_SIZE];
+	int ret;
+
+	/* Seek to data_off for data reading */
+	ret = lseek(src_fd, data_off, SEEK_SET);
+	if (ret<  0) {
+		error("seek source file to %llu failed as %s",
+		       (uint64_t)data_off, strerror(errno));
+		return ret;
+	}
+
+	/* Seek to data_off for data writing, make holes as well */
+	ret = lseek(dest_fd, data_off, SEEK_SET);
+	if (ret<  0) {
+		error("seek dest file to %llu failed as %s",
+		       (uint64_t)data_off, strerror(errno));
+		return ret;
+	}
+
+	while (len>  0) {
+		memset(buf, 0, sizeof(buf));
+		ssize_t n_read = read(src_fd, buf, BUF_SIZE);
+		if (n_read<  0) {

Quoted 7 lines · Jeff Liu

Hello,

This is another SEEK_DATA/SEEK_HOLE tester which is intended to cover multiple extents checking.
I have ran it against btrfs to ensure the tester works, and ran it against XFS to ensure the SEEK_DATA/SEEK_HOLE patch works too.

src/seek_copy_tester.c

Quoted 6 lines

src/seek_copy_tester.c new file +0 -0

new file mode 100755
index 0000000..4971f34
@@ -0,0 +1,674 @@

Do you want to add Author/Copyright and description?

Quoted 5 lines

src/seek_copy_tester.c new file +4 -0

+#include<stdio.h>
+#include<stdlib.h>
+#include<stdint.h>
+#include<stdarg.h>

...

Quoted 13 lines

src/seek_copy_tester.c new file +13 -0

+int
+full_write(int fd, const void *buf, size_t count)
+{
+    int ret = 0;
+    const char *ptr = (const char *) buf;
+
+    while (count>  0) {
+        ssize_t n = write(fd, ptr, count);
+        if (n<  0) {
+            if (errno == EINTR)
+                continue;
+            error("full_write failed as %s", strerror(errno));
+            ret = -1;

src/seek_copy_tester.c line 101

Quoted 5 lines

src/seek_copy_tester.c new file +5 -0

+            break;
+        }
+
+        if (n == 0)
+            break;

Callers of this routine expect the count number of bytes to be written. Write a message if leaving this routine early? An error?

Quoted 8 lines

src/seek_copy_tester.c new file +7 -0

+
+        ptr += n;
+        count -= n;
+    }
+
+    return ret;
+}

...

Quoted 6 lines

src/seek_copy_tester.c new file +6 -0

+int
+create_data_and_holes(int fd, size_t nr_total_bytes, off_t start_offset,
+              uint64_t nr_skip_bytes, uint64_t nr_data_bytes,
+              int wrote_hole_at_eof)
+{
+    int ret = 0;

src/seek_copy_tester.c line 215

Quoted 10 lines

src/seek_copy_tester.c new file +10 -0

+    off_t total = nr_total_bytes;
+    off_t data_len = nr_data_bytes;
+    off_t off = start_offset;
+    char buf[4096];
+
+    memset(buf, 'A', sizeof(buf));
+
+    total -= start_offset;
+    while (total>  0) {
+        do {

You can actually write more than total byte on the last data write. If writing exact total is important, then give do_pwrite() the count:
cnt = MIN(total, sizeof(buf))

src/seek_copy_tester.c line 224

Quoted 9 lines

src/seek_copy_tester.c new file +9 -0

+            ssize_t nr_write = do_pwrite(fd, buf, sizeof(buf), off);
+            if (nr_write<  0) {
+                error("do_pwrite() failed as %s", strerror(errno));
+                ret = -1;
+                goto out;
+            }
+            if (nr_write == 0)
+                break;
+

do_pwrite will return 0 if not an error.

Quoted 2 lines

+            off += nr_write;
            data_len -= nr_write;

These are probably sizeof(buf0 or my cnt not nr_write

Quoted 4 lines

src/seek_copy_tester.c new file +4 -0

+        } while (data_len>  0);
+
+        off += (nr_skip_bytes + nr_data_bytes);
+        total -= off;

...

Quoted 38 lines

src/seek_copy_tester.c new file +38 -0

+
+/*
+ * Copy a data extent from source file to dest file.
+ * @data_off: data offset
+ * @hole_off: hole offset
+ * The length of this extent is (hole_off - data_off).
+ */
+int
+do_extent_copy(int src_fd, int dest_fd, off_t data_off, off_t hole_off)
+{
+    uint64_t len = (uint64_t)(hole_off - data_off);
+    char buf[BUF_SIZE];
+    int ret;
+
+    /* Seek to data_off for data reading */
+    ret = lseek(src_fd, data_off, SEEK_SET);
+    if (ret<  0) {
+        error("seek source file to %llu failed as %s",
+               (uint64_t)data_off, strerror(errno));
+        return ret;
+    }
+
+    /* Seek to data_off for data writing, make holes as well */
+    ret = lseek(dest_fd, data_off, SEEK_SET);
+    if (ret<  0) {
+        error("seek dest file to %llu failed as %s",
+               (uint64_t)data_off, strerror(errno));
+        return ret;
+    }
+
+    while (len>  0) {
+        memset(buf, 0, sizeof(buf));
+        ssize_t n_read = read(src_fd, buf, BUF_SIZE);
+        if (n_read<  0) {
+            if (errno == EINTR)
+                continue;
+
+            error("read source file extent failed as %s",

src/seek_copy_tester.c line 293

Quoted 6 lines

src/seek_copy_tester.c new file +6 -0

+                  strerror(errno));   
+            return n_read;
+        }
+
+        if (n_read == 0)
+            break;

Message? Error?

--Mark Tinguely

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