Recently we found a bug by trigger a page fault when io-vector of
writev is in processing. If do memset between malloc() and write
operations, memset will init the pages. So do memset randomly
maybe help to cover above situation.
Signed-off-by: Zorro Lang <zlang@xxxxxxxxxx>
---
ltp/fsstress.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/ltp/fsstress.c b/ltp/fsstress.c
index 4ff90d5..e1b73e4 100644
--- a/ltp/fsstress.c
+++ b/ltp/fsstress.c
@@ -1924,7 +1924,8 @@ do_aio_rw(int opno, long r, int flags)
off = (off64_t)(lr % MIN(stb.st_size + (1024 * 1024), MAXFSIZE));
off -= (off % align);
off %= maxfsize;
- memset(buf, nameseq & 0xff, len);
+ /* randomly memset maybe trigger page fault at write time */
+ if (random() / 2) memset(buf, nameseq & 0xff, len);
io_prep_pwrite(&iocb, fd, buf, len, off);
} else {
off = (off64_t)(lr % stb.st_size);
@@ -2455,7 +2456,8 @@ dwrite_f(int opno, long r)
buf = memalign(diob.d_mem, len);
off %= maxfsize;
lseek64(fd, off, SEEK_SET);
- memset(buf, nameseq & 0xff, len);
+ /* randomly memset maybe trigger page fault at write time */
+ if (random() / 2) memset(buf, nameseq & 0xff, len);
e = write(fd, buf, len) < 0 ? errno : 0;
free(buf);
if (v)
@@ -3672,7 +3674,8 @@ write_f(int opno, long r)
lseek64(fd, off, SEEK_SET);
len = (random() % FILELEN_MAX) + 1;
buf = malloc(len);
- memset(buf, nameseq & 0xff, len);
+ /* randomly memset maybe trigger page fault at write time */
+ if (random() / 2) memset(buf, nameseq & 0xff, len);
e = write(fd, buf, len) < 0 ? errno : 0;
free(buf);
if (v)
@@ -3733,7 +3736,8 @@ writev_f(int opno, long r)
lseek64(fd, off, SEEK_SET);
len = (random() % FILELEN_MAX) + 1;
buf = malloc(len);
- memset(buf, nameseq & 0xff, len);
+ /* randomly memset maybe trigger page fault at write time */
+ if (random() / 2) memset(buf, nameseq & 0xff, len);
iovcnt = (random() % MIN(len, IOV_MAX)) + 1;
iov = malloc(sizeof(struct iovec) * iovcnt);
--
2.7.4
--
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