os/bluestore: support main/slow device's alloc unit for BlueFS.

This effectively enables having 4K allocation units for BlueFS.
But it doesn't turn it on by default for the sake of performance.
Using main device which lacks enough free large continuous extents
might do the trick though.

Signed-off-by: Igor Fedotov <igor.fedotov@croit.io>

1 files changed, 81 insertions, 41 deletions

diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
index 529a34fc229..326cbce5472 100644
--- a/src/os/bluestore/BlueFS.cc
+++ b/src/os/bluestore/BlueFS.cc
@@ -377,6 +377,16 @@ void BlueFS::_init_logger()
                     "Average lock duration while compacting bluefs log",
                     "c_lt",
                     PerfCountersBuilder::PRIO_INTERESTING);
+  b.add_u64_counter(l_bluefs_alloc_shared_dev_fallbacks, "alloc_slow_fallback",
+		    "Amount of allocations that required fallback to "
+                    " slow/shared device",
+		     "asdf",
+		    PerfCountersBuilder::PRIO_USEFUL);
+  b.add_u64_counter(l_bluefs_alloc_shared_size_fallbacks, "alloc_slow_size_fallback",
+		    "Amount of allocations that required fallback to shared device's "
+                    "regular unit size",
+		     "assf",
+		    PerfCountersBuilder::PRIO_USEFUL);
   b.add_u64(l_bluefs_read_zeros_candidate, "read_zeros_candidate",
 	    "How many times bluefs read found page with all 0s");
   b.add_u64(l_bluefs_read_zeros_errors, "read_zeros_errors",
@@ -586,6 +596,7 @@ int BlueFS::mkfs(uuid_d osd_uuid, const bluefs_layout_t& layout)
   int r = _allocate(
     vselector->select_prefer_bdev(log_file->vselector_hint),
     cct->_conf->bluefs_max_log_runway,
+    0,
     &log_file->fnode);
   vselector->add_usage(log_file->vselector_hint, log_file->fnode);
   ceph_assert(r == 0);
@@ -1098,12 +1109,17 @@ int BlueFS::_check_allocations(const bluefs_fnode_t& fnode,
     auto id = e.bdev;
     bool fail = false;
     ceph_assert(id < MAX_BDEV);
+    ceph_assert(bdev[id]);
+    // let's use minimal allocation unit we can have
+    auto alloc_unit = bdev[id]->get_block_size();
+
     if (int r = _verify_alloc_granularity(id, e.offset, e.length,
+                                          alloc_unit,
 					  op_name); r < 0) {
       return r;
     }
 
-    apply_for_bitset_range(e.offset, e.length, alloc_size[id], used_blocks[id],
+    apply_for_bitset_range(e.offset, e.length, alloc_unit, used_blocks[id],
       [&](uint64_t pos, boost::dynamic_bitset<uint64_t> &bs) {
 	if (is_alloc == bs.test(pos)) {
 	  fail = true;
@@ -1125,31 +1141,14 @@ int BlueFS::_check_allocations(const bluefs_fnode_t& fnode,
 }
 
 int BlueFS::_verify_alloc_granularity(
-  __u8 id, uint64_t offset, uint64_t length, const char *op)
+  __u8 id, uint64_t offset, uint64_t length, uint64_t alloc_unit, const char *op)
 {
-  if ((offset & (alloc_size[id] - 1)) ||
-      (length & (alloc_size[id] - 1))) {
+  if ((offset & (alloc_unit - 1)) ||
+      (length & (alloc_unit - 1))) {
     derr << __func__ << " " << op << " of " << (int)id
 	 << ":0x" << std::hex << offset << "~" << length << std::dec
 	 << " does not align to alloc_size 0x"
-	 << std::hex << alloc_size[id] << std::dec << dendl;
-    // be helpful
-    auto need = alloc_size[id];
-    while (need && ((offset & (need - 1)) ||
-		    (length & (need - 1)))) {
-      need >>= 1;
-    }
-    if (need) {
-      const char *which;
-      if (id == BDEV_SLOW ||
-	  (id == BDEV_DB && !bdev[BDEV_SLOW])) {
-	which = "bluefs_shared_alloc_size";
-      } else {
-	which = "bluefs_alloc_size";
-      }
-      derr << "work-around by setting " << which << " = " << need
-	   << " for this OSD" << dendl;
-    }
+	 << std::hex << alloc_unit << std::dec << dendl;
     return -EFAULT;
   }
   return 0;
@@ -1186,8 +1185,11 @@ int BlueFS::_replay(bool noop, bool to_stdout)
   if (!noop) {
     if (cct->_conf->bluefs_log_replay_check_allocations) {
       for (size_t i = 0; i < MAX_BDEV; ++i) {
-	if (alloc_size[i] != 0 && bdev[i] != nullptr) {
-	  used_blocks[i].resize(round_up_to(bdev[i]->get_size(), alloc_size[i]) / alloc_size[i]);
+	if (bdev[i] != nullptr) {
+          // let's use minimal allocation unit we can have
+          auto au = bdev[i]->get_block_size();
+          //hmm... on 32TB/4K drive this would take 1GB RAM!!!
+	  used_blocks[i].resize(round_up_to(bdev[i]->get_size(), au) / au);
 	}
       }
       // check initial log layout
@@ -1767,7 +1769,7 @@ int BlueFS::device_migrate_to_existing(
       }
 
       // write entire file
-      auto l = _allocate_without_fallback(dev_target, bl.length(),
+      auto l = _allocate_without_fallback(dev_target, bl.length(), 0,
         &file_ref->fnode);
       if (l < 0) {
 	derr << __func__ << " unable to allocate len 0x" << std::hex
@@ -1907,7 +1909,7 @@ int BlueFS::device_migrate_to_new(
       }
 
       // write entire file
-      auto l = _allocate_without_fallback(dev_target, bl.length(),
+      auto l = _allocate_without_fallback(dev_target, bl.length(), 0,
         &file_ref->fnode);
       if (l < 0) {
 	derr << __func__ << " unable to allocate len 0x" << std::hex
@@ -2551,8 +2553,8 @@ void BlueFS::_rewrite_log_and_layout_sync_LNF_LD(bool allocate_with_fallback,
   dout(20) << __func__ << " compacted_meta_need " << compacted_meta_need << dendl;
 
   int r = allocate_with_fallback ?
-    _allocate(log_dev, compacted_meta_need, &fnode_tail) :
-    _allocate_without_fallback(log_dev, compacted_meta_need, &fnode_tail);
+    _allocate(log_dev, compacted_meta_need, 0, &fnode_tail) :
+    _allocate_without_fallback(log_dev, compacted_meta_need, 0, &fnode_tail);
   ceph_assert(r == 0);
 
 
@@ -2563,8 +2565,8 @@ void BlueFS::_rewrite_log_and_layout_sync_LNF_LD(bool allocate_with_fallback,
 
   bluefs_fnode_t fnode_starter(log_file->fnode.ino, 0, mtime);
   r = allocate_with_fallback ?
-    _allocate(log_dev, starter_need, &fnode_starter) :
-    _allocate_without_fallback(log_dev, starter_need, &fnode_starter);
+    _allocate(log_dev, starter_need, 0, &fnode_starter) :
+    _allocate_without_fallback(log_dev, starter_need, 0, &fnode_starter);
   ceph_assert(r == 0);
 
   // 1.4 Building starter fnode
@@ -2766,6 +2768,7 @@ void BlueFS::_compact_log_async_LD_LNF_D() //also locks FW for new_writer
            << " need 0x" << cct->_conf->bluefs_max_log_runway << std::dec << dendl;
   int r = _allocate(vselector->select_prefer_bdev(log_file->vselector_hint),
 		    cct->_conf->bluefs_max_log_runway,
+                    0,
                     &fnode_tail);
   ceph_assert(r == 0);
 
@@ -2837,6 +2840,7 @@ void BlueFS::_compact_log_async_LD_LNF_D() //also locks FW for new_writer
     // do allocate
     r = _allocate(vselector->select_prefer_bdev(log_file->vselector_hint),
                   compacted_meta_need,
+                  0,
                   &fnode_pre_tail);
     ceph_assert(r == 0);
     // build trailing list of extents in fnode_tail,
@@ -2858,6 +2862,7 @@ void BlueFS::_compact_log_async_LD_LNF_D() //also locks FW for new_writer
   // and now allocate and store at new_log_fnode
   r = _allocate(vselector->select_prefer_bdev(log_file->vselector_hint),
                 starter_need,
+                0,
                 &new_log->fnode);
   ceph_assert(r == 0);
 
@@ -3065,6 +3070,7 @@ int64_t BlueFS::_maybe_extend_log()
     int r = _allocate(
       vselector->select_prefer_bdev(log.writer->file->vselector_hint),
       cct->_conf->bluefs_max_log_runway,
+      0,
       &log.writer->file->fnode);
     ceph_assert(r == 0);
     vselector->add_usage(log.writer->file->vselector_hint, log.writer->file->fnode);
@@ -3366,6 +3372,7 @@ int BlueFS::_flush_range_F(FileWriter *h, uint64_t offset, uint64_t length)
     // in _flush_and_sync_log.
     int r = _allocate(vselector->select_prefer_bdev(h->file->vselector_hint),
 		      offset + length - allocated,
+                      0,
 		      &h->file->fnode);
     if (r < 0) {
       derr << __func__ << " allocated: 0x" << std::hex << allocated
@@ -3727,18 +3734,24 @@ const char* BlueFS::get_device_name(unsigned id)
 }
 
 int BlueFS::_allocate_without_fallback(uint8_t id, uint64_t len,
+                      uint64_t alloc_unit,
 		      bluefs_fnode_t* node)
 {
-  dout(10) << __func__ << " len 0x" << std::hex << len << std::dec
+  dout(10) << __func__ << " len 0x" << std::hex << len
+           << " alloc_unit hint 0x " << alloc_unit
+           << std::dec
            << " from " << (int)id << dendl;
   assert(id < alloc.size());
   if (!alloc[id]) {
     return -ENOENT;
   }
+  if (!alloc_unit) {
+   alloc_unit = alloc_size[id];
+  }
   PExtentVector extents;
   extents.reserve(4);  // 4 should be (more than) enough for most allocations
-  int64_t need = round_up_to(len, alloc_size[id]);
-  int64_t alloc_len = alloc[id]->allocate(need, alloc_size[id], 0, &extents);
+  int64_t need = round_up_to(len, alloc_unit);
+  int64_t alloc_len = alloc[id]->allocate(need, alloc_unit, 0, &extents);
   if (alloc_len < 0 || alloc_len < need) {
     if (alloc_len > 0) {
       alloc[id]->release(extents);
@@ -3754,6 +3767,15 @@ int BlueFS::_allocate_without_fallback(uint8_t id, uint64_t len,
          << ", fragmentation " << alloc[id]->get_fragmentation()
          << ", allocated 0x" << (alloc_len > 0 ? alloc_len : 0)
 	 << std::dec << dendl;
+    if (is_shared_alloc(id) && alloc_unit != shared_alloc->alloc_unit) {
+      // fallback to shared alloc unit is permitted though
+      alloc_unit = shared_alloc->alloc_unit;
+      dout(20) << __func__ << " fallback to bdev "
+	       << (int)id
+               << " with alloc unit 0x" << std::hex << alloc_unit
+               << std::dec << dendl;
+      return _allocate_without_fallback(id, len, alloc_unit, node);
+    }
     alloc[id]->dump();
     return -ENOSPC;
   }
@@ -3768,22 +3790,27 @@ int BlueFS::_allocate_without_fallback(uint8_t id, uint64_t len,
 }
 
 int BlueFS::_allocate(uint8_t id, uint64_t len,
+		      uint64_t alloc_unit,
 		      bluefs_fnode_t* node)
 {
-  dout(10) << __func__ << " len 0x" << std::hex << len << std::dec
-           << " from " << (int)id << dendl;
+  dout(10) << __func__ << " len 0x" << std::hex << len
+           << " alloc unit hint 0x" << alloc_unit
+           << std::dec << " from " << (int)id << dendl;
   ceph_assert(id < alloc.size());
   int64_t alloc_len = 0;
   PExtentVector extents;
   uint64_t hint = 0;
   int64_t need = len;
   if (alloc[id]) {
-    need = round_up_to(len, alloc_size[id]);
+    if (!alloc_unit) {
+      alloc_unit = alloc_size[id];
+    }
+    need = round_up_to(len, alloc_unit);
     if (!node->extents.empty() && node->extents.back().bdev == id) {
       hint = node->extents.back().end();
     }   
     extents.reserve(4);  // 4 should be (more than) enough for most allocations
-    alloc_len = alloc[id]->allocate(need, alloc_size[id], hint, &extents);
+    alloc_len = alloc[id]->allocate(need, alloc_unit, hint, &extents);
   }
   if (alloc_len < 0 || alloc_len < need) {
     if (alloc[id]) {
@@ -3796,20 +3823,32 @@ int BlueFS::_allocate(uint8_t id, uint64_t len,
               << ", allocator type " << alloc[id]->get_type()
               << ", capacity 0x" << alloc[id]->get_capacity()
               << ", block size 0x" << alloc[id]->get_block_size()
-              << ", alloc size 0x" << alloc_size[id]
+              << ", alloc unit 0x" << alloc_unit
               << ", free 0x" << alloc[id]->get_free()
               << ", fragmentation " << alloc[id]->get_fragmentation()
               << ", allocated 0x" << (alloc_len > 0 ? alloc_len : 0)
 	      << std::dec << dendl;
     } else {
-      dout(20) << __func__ << " alloc-id not set on index="<< (int)id << " unable to allocate 0x" << std::hex << need
+      dout(20) << __func__ << " alloc-id not set on index="<< (int)id
+               << " unable to allocate 0x" << std::hex << need
 	       << " on bdev " << (int)id << std::dec << dendl;
     }
-    if (id != BDEV_SLOW) {
+    if (alloc[id] && is_shared_alloc(id) && alloc_unit != shared_alloc->alloc_unit) {
+      alloc_unit = shared_alloc->alloc_unit;
+      dout(20) << __func__ << " fallback to bdev "
+	       << (int)id
+               << " with alloc unit 0x" << std::hex << alloc_unit
+               << std::dec << dendl;
+      logger->inc(l_bluefs_alloc_shared_size_fallbacks);
+      return _allocate(id, len, alloc_unit, node);
+    } else if (id != BDEV_SLOW && alloc[id + 1]) {
       dout(20) << __func__ << " fallback to bdev "
 	       << (int)id + 1
 	       << dendl;
-      return _allocate(id + 1, len, node);
+      if (alloc[id] && is_shared_alloc(id + 1)) {
+        logger->inc(l_bluefs_alloc_shared_dev_fallbacks);
+      }
+      return _allocate(id + 1, len, 0, node); // back to default alloc unit
     } else {
       derr << __func__ << " allocation failed, needed 0x" << std::hex << need
            << dendl;
@@ -3851,6 +3890,7 @@ int BlueFS::preallocate(FileRef f, uint64_t off, uint64_t len)/*_LF*/
     vselector->sub_usage(f->vselector_hint, f->fnode);
     int r = _allocate(vselector->select_prefer_bdev(f->vselector_hint),
       want,
+      0,
       &f->fnode);
     vselector->add_usage(f->vselector_hint, f->fnode);
     if (r < 0)