Improve verify pattern failure logging

Show number of bad bits and block offset.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/verify.c b/verify.c
index 96a2f120fbb4028fb3732055311eabad32fc5e14..f5ed51a5354c35486c727ed18c7591886fef3bde 100644 (file)
--- a/verify.c
+++ b/verify.c
@@ -338,6 +338,14 @@ static int verify_io_u_md5(struct verify_header *hdr, struct io_u *io_u,
        return 0;
 }
 
+static unsigned int hweight8(unsigned int w)
+{
+       unsigned int res = w - ((w >> 1) & 0x55);
+
+       res = (res & 0x33) + ((res >> 2) & 0x33);
+       return (res + (res >> 4)) & 0x0F;
+}
+
 int verify_io_u_pattern(unsigned long pattern, unsigned long pattern_size,
                         char* buf, unsigned int len, unsigned int mod)
 {
@@ -350,8 +358,15 @@ int verify_io_u_pattern(unsigned long pattern, unsigned long pattern_size,
        }
 
        for (i = 0; i < len; i++) {
-               if (buf[i] != split_pattern[mod])
+               if (buf[i] != split_pattern[mod]) {
+                       unsigned int bits;
+
+                       bits = hweight8(buf[i] ^ split_pattern[mod]);
+                       log_err("fio: got pattern %x, wanted %x. Bad bits %d\n",
+                               buf[i], split_pattern[mod], bits);
+                       log_err("fio: bad pattern block offset %u\n", i);
                        return 1;
+               }
                mod++;
                if (mod == pattern_size)
                        mod = 0;
@@ -374,29 +389,28 @@ int verify_io_u(struct thread_data *td, struct io_u *io_u)
        if (td->o.verify_interval)
                hdr_inc = td->o.verify_interval;
 
-       for (p = io_u->buf; p < io_u->buf + io_u->buflen; p += hdr_inc) {
+       for (p = io_u->buf; p < io_u->buf + io_u->buflen; p += hdr_inc, hdr_num++) {
                hdr_size = __hdr_size(td->o.verify);
                if (td->o.verify_offset)
                        memswp(p, p + td->o.verify_offset, hdr_size);
                hdr = p;
 
+               if (hdr->fio_magic != FIO_HDR_MAGIC) {
+                       log_err("Bad verify header %x\n", hdr->fio_magic);
+                       return EIO;
+               }
+
                if (td->o.verify_pattern_bytes) {
                        ret = verify_io_u_pattern(td->o.verify_pattern,
                                                  td->o.verify_pattern_bytes,
                                                  p + hdr_size,
                                                  hdr_inc - hdr_size,
                                                  hdr_size % 4);
-                       if (ret) {
-                               log_err("pattern: verify failed at %llu/%u\n",
+                       if (ret)
+                               log_err("fio: verify failed at %llu/%u\n",
                                        io_u->offset + hdr_num * hdr->len,
-                                       hdr->len);
-                               return ret;
-                       }
-               }
-
-               if (hdr->fio_magic != FIO_HDR_MAGIC) {
-                       log_err("Bad verify header %x\n", hdr->fio_magic);
-                       return EIO;
+                                       hdr->len);
+                       continue;
                }
 
                switch (hdr->verify_type) {
@@ -428,7 +442,6 @@ int verify_io_u(struct thread_data *td, struct io_u *io_u)
                        log_err("Bad verify type %u\n", hdr->verify_type);
                        ret = 1;
                }
-               hdr_num++;
        }
 
        return 0;