os/bluestore: Add an option to choose bluefs direct or buffered io

For now, set default to buffered io; after rocksdb block cache
has ability to cache writes, we will set default to direct io.

Signed-off-by: Jianjian Huo <jianjian.huo@ssi.samsung.com>

diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index 326a78fdb6ae8b381e534cc9b77b477fee62e82d..5648a35c1ed3ca101b8b697f428186bc7cfc1d04 100644 (file)
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -934,6 +934,7 @@ OPTION(bluestore_bluefs_min_ratio, OPT_FLOAT, .02)  // min fs free / total free
 OPTION(bluestore_bluefs_max_ratio, OPT_FLOAT, .90)  // max fs free / total free
 OPTION(bluestore_bluefs_gift_ratio, OPT_FLOAT, .02) // how much to add at a time
 OPTION(bluestore_bluefs_reclaim_ratio, OPT_FLOAT, .20) // how much to reclaim at a time
+OPTION(bluestore_bluefs_buffered_io, OPT_BOOL, true)
 // If you want to use spdk driver, you need to specify NVMe serial number here
 // with "spdk:" prefix.
 // Users can use 'lspci -vvv -d 8086:0953 | grep "Device Serial Number"' to

diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
index 3a4610a4f08bf1232e3d792143b3bef699c422cd..83f02d8aa1def553f84e7c5be16c5f4d32724385 100644 (file)
--- a/src/os/bluestore/BlueFS.cc
+++ b/src/os/bluestore/BlueFS.cc
@@ -740,7 +740,8 @@ int BlueFS::_read_random(
     }
     dout(20) << __func__ << " read buffered " << x_off << "~" << l << " of "
               << *p << dendl;
-    int r = bdev[p->bdev]->read_random(p->offset + x_off, l, out, false);
+    int r = bdev[p->bdev]->read_random(p->offset + x_off, l, out,
+                                      g_conf->bluestore_bluefs_buffered_io);
     assert(r == 0);
     off += l;
     len -= l;
@@ -799,7 +800,7 @@ int BlueFS::_read(
       dout(20) << __func__ << " fetching " << x_off << "~" << l << " of "
               << *p << dendl;
       int r = bdev[p->bdev]->read(p->offset + x_off, l, &buf->bl, ioc[p->bdev],
-                                 false);
+                                 g_conf->bluestore_bluefs_buffered_io);
       assert(r == 0);
     }
     left = buf->get_buf_remaining(off);
@@ -1123,7 +1124,8 @@ int BlueFS::_flush_range(FileWriter *h, uint64_t offset, uint64_t length)
       h->tail_block.substr_of(bl, bl.length() - tail, tail);
       t.append_zero(super.block_size - tail);
     }
-    bdev[p->bdev]->aio_write(p->offset + x_off, t, h->iocv[p->bdev], false);
+    bdev[p->bdev]->aio_write(p->offset + x_off, t, h->iocv[p->bdev],
+                            g_conf->bluestore_bluefs_buffered_io);
     bloff += x_len;
     length -= x_len;
     ++p;