f2fs_io: add mmap read operation

This patch adds an option, mmap, when reading data.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
index 30544c1..6266454 100644 (file)
--- a/tools/f2fs_io/f2fs_io.c
+++ b/tools/f2fs_io/f2fs_io.c
@@ -489,15 +489,18 @@ static void do_write(int argc, char **argv, const struct cmd_desc *cmd)
 "IO can be\n"                                          \
 "  buffered : buffered IO\n"                           \
 "  dio      : direct IO\n"                             \
+"  mmap     : mmap IO\n"                               \
 
 static void do_read(int argc, char **argv, const struct cmd_desc *cmd)
 {
        u64 buf_size = 0, ret = 0, read_cnt = 0;
        u64 offset;
        char *buf = NULL;
+       char *data;
        char *print_buf = NULL;
        unsigned bs, count, i, print_bytes;
        int flags = 0;
+       int do_mmap = 0;
        int fd;
 
        if (argc != 7) {
@@ -518,6 +521,8 @@ static void do_read(int argc, char **argv, const struct cmd_desc *cmd)
        count = atoi(argv[3]);
        if (!strcmp(argv[4], "dio"))
                flags |= O_DIRECT;
+       else if (!strcmp(argv[4], "mmap"))
+               do_mmap = 1;
        else if (strcmp(argv[4], "buffered"))
                die("Wrong IO type");
 
@@ -529,8 +534,20 @@ static void do_read(int argc, char **argv, const struct cmd_desc *cmd)
 
        fd = xopen(argv[6], O_RDONLY | flags, 0);
 
+       if (do_mmap) {
+               data = mmap(NULL, count * buf_size, PROT_READ,
+                                               MAP_SHARED, fd, offset);
+               if (data == MAP_FAILED)
+                       die("Mmap failed");
+       }
+
        for (i = 0; i < count; i++) {
-               ret = pread(fd, buf, buf_size, offset + buf_size * i);
+               if (do_mmap) {
+                       memcpy(buf, data + offset + buf_size * i, buf_size);
+                       ret = buf_size;
+               } else {
+                       ret = pread(fd, buf, buf_size, offset + buf_size * i);
+               }
                if (ret != buf_size)
                        break;