pattern: Add support for files in buffer_pattern argument.

It is useful to be able to initialize the buffer contents using an
input file (e.g. when testing certain pathological patterns for
compression). Add support to the buffer_pattern input argument for
reading data from a file via enclosing the filename in ``''``.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-By: Muli Ben-Yehuda <muli@lightbitslabs.com>
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/HOWTO b/HOWTO
index 289c51808a142af3a18a61aa89078a3c1e372ac0..d3a578378ab49e43e89fd33be9cdc6046b22e674 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1401,11 +1401,18 @@ Buffers and memory
 
 .. option:: buffer_pattern=str
 
-       If set, fio will fill the I/O buffers with this pattern. If not set, the
-       contents of I/O buffers is defined by the other options related to buffer
-       contents. The setting can be any pattern of bytes, and can be prefixed with
-       0x for hex values. It may also be a string, where the string must then be
-       wrapped with ``""``, e.g.::
+       If set, fio will fill the I/O buffers with this pattern or with the contents
+       of a file. If not set, the contents of I/O buffers are defined by the other
+       options related to buffer contents. The setting can be any pattern of bytes,
+       and can be prefixed with 0x for hex values. It may also be a string, where
+       the string must then be wrapped with ``""``. Or it may also be a filename,
+       where the filename must be wrapped with ``''`` in which case the file is
+       opened and read. Note that not all the file contents will be read if that
+       would cause the buffers to overflow. So, for example::
+
+               buffer_pattern='filename'
+
+       or::
 
                buffer_pattern="abcd"
 
@@ -1419,7 +1426,7 @@ Buffers and memory
 
        Also you can combine everything together in any order::
 
-               buffer_pattern=0xdeadface"abcd"-12
+               buffer_pattern=0xdeadface"abcd"-12'filename'
 
 .. option:: dedupe_percentage=int
 

diff --git a/lib/pattern.c b/lib/pattern.c
index 0aeb935266fa129d2995a4c49f94b0f0c76b1bc2..420d74a9a4338d56b605a7a6a5806466a582525a 100644 (file)
--- a/lib/pattern.c
+++ b/lib/pattern.c
@@ -4,12 +4,74 @@
 #include <limits.h>
 #include <errno.h>
 #include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 #include "strntol.h"
 #include "pattern.h"
 #include "../minmax.h"
 #include "../oslib/strcasestr.h"
 
+/**
+ * parse_file() - parses binary file to fill buffer
+ * @beg - string input, extract filename from this
+ * @out - output buffer where parsed number should be put
+ * @out_len - length of the output buffer
+ * @filled - pointer where number of bytes successfully
+ *           parsed will be put
+ *
+ * Returns the end pointer where parsing has been stopped.
+ * In case of parsing error or lack of bytes in output buffer
+ * NULL will be returned.
+ */
+static const char *parse_file(const char *beg, char *out,
+                             unsigned int out_len,
+                             unsigned int *filled)
+{
+       const char *end;
+       char *file;
+       int fd;
+       ssize_t count;
+
+       if (!out_len)
+               goto err_out;
+
+       assert(*beg == '\'');
+       beg++;
+       end = strchr(beg, '\'');
+       if (!end)
+               goto err_out;
+
+       file = strndup(beg, end - beg);
+       if (file == NULL)
+               goto err_out;
+
+       fd = open(file, O_RDONLY);
+       if (fd < 0)
+               goto err_free_out;
+
+       count = read(fd, out, out_len);
+       if (count == -1)
+               goto err_free_close_out;
+
+       *filled = count;
+       close(fd);
+       free(file);
+
+       /* Catch up quote */
+       return end + 1;
+
+err_free_close_out:
+       close(fd);
+err_free_out:
+       free(file);
+err_out:
+       return NULL;
+
+}
+
 /**
  * parse_string() - parses string in double quotes, like "abc"
  * @beg - string input
@@ -271,6 +333,9 @@ int parse_and_fill_pattern(const char *in, unsigned int in_len,
                parsed_fmt = 0;
 
                switch (*beg) {
+               case '\'':
+                       end = parse_file(beg, out, out_len, &filled);
+                       break;
                case '"':
                        end = parse_string(beg, out, out_len, &filled);
                        break;