os/bluestore/BlueStore: Don't leak trim overlay data before write.

Suppose: bluestore_overlay_max_length=bluestore_min_alloc_size;
bluestore_overlay_max = 2;
For the following ops:
write(off=0, len=4096) --->write into overlay
write(off=4096, len=4096)-->write into overlay
write(off=0, len=bluestore_min_alloc_size)-->because overlay_map.size()
>=2, it allocate a extent.

It should trim overlay data(0,4096) &(4096, 4096),and then write(0,
bluestore_min_alloc_size).
But the original code don't trim overlay data.
This make the later read data is orignal data rather that new data.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 96a10f423bdfdefbe0563d61098b2ef466c75b3e..c52f3371d51068d72f4b1a0e4c31486d47b716da 100644 (file)
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -5538,6 +5538,7 @@ int BlueStore::_do_write(
        uint64_t x_off = offset - bp->first;
        dout(20) << __func__ << " write " << offset << "~" << length
                 << " x_off " << x_off << dendl;
+       _do_overlay_trim(txc, o, offset, length);
        bdev->aio_write(bp->second.offset + x_off, bl, &txc->ioc, buffered);
        bp->second.clear_flag(bluestore_extent_t::FLAG_UNWRITTEN);
        bp->second.clear_flag(bluestore_extent_t::FLAG_COW_HEAD);