From: Denis Plotnikov <dplotnikov@virtuozzo.com>
The patch allows to provide a pattern file for write
command. There was no similar ability before.
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Message-id: 20190820164616.4072-1-dplotnikov@virtuozzo.com
Reviewed-by: Eric Blake <eblake@redhat.com>
[mreitz: Keep optstring in alphabetical order]
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
qemu-io-cmds.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 93 insertions(+), 6 deletions(-)
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 8904733961..d46fa166d3 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -350,6 +350,79 @@ static void qemu_io_free(void *p)
qemu_vfree(p);
}
+/*
+ * qemu_io_alloc_from_file()
+ *
+ * Allocates the buffer and populates it with the content of the given file
+ * up to @len bytes. If the file length is less than @len, then the buffer
+ * is populated with the file content cyclically.
+ *
+ * @blk - the block backend where the buffer content is going to be written to
+ * @len - the buffer length
+ * @file_name - the file to read the content from
+ *
+ * Returns: the buffer pointer on success
+ * NULL on error
+ */
+static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len,
+ const char *file_name)
+{
+ char *buf, *buf_origin;
+ FILE *f = fopen(file_name, "r");
+ int pattern_len;
+
+ if (!f) {
+ perror(file_name);
+ return NULL;
+ }
+
+ if (qemuio_misalign) {
+ len += MISALIGN_OFFSET;
+ }
+
+ buf_origin = buf = blk_blockalign(blk, len);
+
+ if (qemuio_misalign) {
+ buf_origin += MISALIGN_OFFSET;
+ buf += MISALIGN_OFFSET;
+ len -= MISALIGN_OFFSET;
+ }
+
+ pattern_len = fread(buf_origin, 1, len, f);
+
+ if (ferror(f)) {
+ perror(file_name);
+ goto error;
+ }
+
+ if (pattern_len == 0) {
+ fprintf(stderr, "%s: file is empty\n", file_name);
+ goto error;
+ }
+
+ fclose(f);
+
+ if (len > pattern_len) {
+ len -= pattern_len;
+ buf += pattern_len;
+
+ while (len > 0) {
+ size_t len_to_copy = MIN(pattern_len, len);
+
+ memcpy(buf, buf_origin, len_to_copy);
+
+ len -= len_to_copy;
+ buf += len_to_copy;
+ }
+ }
+
+ return buf_origin;
+
+error:
+ qemu_io_free(buf_origin);
+ return NULL;
+}
+
static void dump_buffer(const void *buffer, int64_t offset, int64_t len)
{
uint64_t i;
@@ -948,6 +1021,7 @@ static void write_help(void)
" -n, -- with -z, don't allow slow fallback\n"
" -p, -- ignored for backwards compatibility\n"
" -P, -- use different pattern to fill file\n"
+" -s, -- use a pattern file to fill the write buffer\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quiet mode, do not show I/O statistics\n"
" -u, -- with -z, allow unmapping\n"
@@ -964,7 +1038,7 @@ static const cmdinfo_t write_cmd = {
.perm = BLK_PERM_WRITE,
.argmin = 2,
.argmax = -1,
- .args = "[-bcCfnquz] [-P pattern] off len",
+ .args = "[-bcCfnquz] [-P pattern | -s source_file] off len",
.oneline = "writes a number of bytes at a specified offset",
.help = write_help,
};
@@ -973,7 +1047,7 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
{
struct timespec t1, t2;
bool Cflag = false, qflag = false, bflag = false;
- bool Pflag = false, zflag = false, cflag = false;
+ bool Pflag = false, zflag = false, cflag = false, sflag = false;
int flags = 0;
int c, cnt, ret;
char *buf = NULL;
@@ -982,8 +1056,9 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
/* Some compilers get confused and warn if this is not initialized. */
int64_t total = 0;
int pattern = 0xcd;
+ const char *file_name = NULL;
- while ((c = getopt(argc, argv, "bcCfnpP:quz")) != -1) {
+ while ((c = getopt(argc, argv, "bcCfnpP:qs:uz")) != -1) {
switch (c) {
case 'b':
bflag = true;
@@ -1013,6 +1088,10 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
case 'q':
qflag = true;
break;
+ case 's':
+ sflag = true;
+ file_name = optarg;
+ break;
case 'u':
flags |= BDRV_REQ_MAY_UNMAP;
break;
@@ -1050,8 +1129,9 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
return -EINVAL;
}
- if (zflag && Pflag) {
- printf("-z and -P cannot be specified at the same time\n");
+ if (zflag + Pflag + sflag > 1) {
+ printf("Only one of -z, -P, and -s "
+ "can be specified at the same time\n");
return -EINVAL;
}
@@ -1087,7 +1167,14 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
}
if (!zflag) {
- buf = qemu_io_alloc(blk, count, pattern);
+ if (sflag) {
+ buf = qemu_io_alloc_from_file(blk, count, file_name);
+ if (!buf) {
+ return -EINVAL;
+ }
+ } else {
+ buf = qemu_io_alloc(blk, count, pattern);
+ }
}
clock_gettime(CLOCK_MONOTONIC, &t1);
--
2.21.0