Merge "libnetutils: Restore dhcptool"
diff --git a/adb/adb.cpp b/adb/adb.cpp
index 23f6580..808d8ff 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -1241,10 +1241,7 @@
         return true;
     });
 
-    D("update_transport_status: transports_ready = %s", result ? "true" : "false");
-
     bool ready;
-
     {
         std::lock_guard<std::mutex> lock(init_mutex);
         transports_ready = result;
@@ -1252,14 +1249,11 @@
     }
 
     if (ready) {
-        D("update_transport_status: notifying");
         init_cv.notify_all();
     }
 }
 
 void adb_notify_device_scan_complete() {
-    D("device scan complete");
-
     {
         std::lock_guard<std::mutex> lock(init_mutex);
         device_scan_complete = true;
diff --git a/adb/client/usb_libusb.cpp b/adb/client/usb_libusb.cpp
index 18a8ff2..fc32469 100644
--- a/adb/client/usb_libusb.cpp
+++ b/adb/client/usb_libusb.cpp
@@ -151,10 +151,7 @@
 static auto& usb_handles = *new std::unordered_map<std::string, std::unique_ptr<usb_handle>>();
 static auto& usb_handles_mutex = *new std::mutex();
 
-static std::thread* device_poll_thread = nullptr;
-static bool terminate_device_poll_thread = false;
-static auto& device_poll_mutex = *new std::mutex();
-static auto& device_poll_cv = *new std::condition_variable();
+static libusb_hotplug_callback_handle hotplug_handle;
 
 static std::string get_device_address(libusb_device* device) {
     return StringPrintf("usb:%d:%d", libusb_get_bus_number(device),
@@ -175,6 +172,17 @@
     path += "/serial";
     return path;
 }
+
+static std::string get_device_dev_path(libusb_device* device) {
+    uint8_t ports[7];
+    int port_count = libusb_get_port_numbers(device, ports, 7);
+    if (port_count < 0) return "";
+    return StringPrintf("/dev/bus/usb/%03u/%03u", libusb_get_bus_number(device), ports[0]);
+}
+
+static bool is_device_accessible(libusb_device* device) {
+    return access(get_device_dev_path(device).c_str(), R_OK | W_OK) == 0;
+}
 #endif
 
 static bool endpoint_is_output(uint8_t endpoint) {
@@ -229,7 +237,7 @@
             // TODO: Is this assumption valid?
             LOG(VERBOSE) << "skipping interface with incorrect num_altsetting at " << device_address
                          << " (interface " << interface_num << ")";
-            return;
+            continue;
         }
 
         const libusb_interface_descriptor& interface_desc = interface.altsetting[0];
@@ -237,7 +245,7 @@
                               interface_desc.bInterfaceProtocol)) {
             LOG(VERBOSE) << "skipping non-adb interface at " << device_address << " (interface "
                          << interface_num << ")";
-            return;
+            continue;
         }
 
         LOG(VERBOSE) << "found potential adb interface at " << device_address << " (interface "
@@ -253,7 +261,7 @@
             const uint8_t transfer_type = endpoint_attr & LIBUSB_TRANSFER_TYPE_MASK;
 
             if (transfer_type != LIBUSB_TRANSFER_TYPE_BULK) {
-                return;
+                continue;
             }
 
             if (endpoint_is_output(endpoint_addr) && !found_out) {
@@ -371,33 +379,62 @@
     }
 
     register_usb_transport(usb_handle_raw, device_serial.c_str(), device_address.c_str(), writable);
-
     LOG(INFO) << "registered new usb device '" << device_serial << "'";
 }
 
-static void poll_for_devices() {
-    libusb_device** list;
-    adb_thread_setname("device poll");
-    while (true) {
-        const ssize_t device_count = libusb_get_device_list(nullptr, &list);
+static std::atomic<int> connecting_devices(0);
 
-        LOG(VERBOSE) << "found " << device_count << " attached devices";
-
-        for (ssize_t i = 0; i < device_count; ++i) {
-            process_device(list[i]);
+static void device_connected(libusb_device* device) {
+#if defined(__linux__)
+    // Android's host linux libusb uses netlink instead of udev for device hotplug notification,
+    // which means we can get hotplug notifications before udev has updated ownership/perms on the
+    // device. Since we're not going to be able to link against the system's libudev any time soon,
+    // hack around this by checking for accessibility in a loop.
+    ++connecting_devices;
+    auto thread = std::thread([device]() {
+        std::string device_path = get_device_dev_path(device);
+        auto start = std::chrono::steady_clock::now();
+        while (std::chrono::steady_clock::now() - start < 500ms) {
+            if (is_device_accessible(device)) {
+                break;
+            }
+            std::this_thread::sleep_for(10ms);
         }
 
-        libusb_free_device_list(list, 1);
+        process_device(device);
+        --connecting_devices;
+    });
+    thread.detach();
+#else
+    process_device(device);
+#endif
+}
 
-        adb_notify_device_scan_complete();
+static void device_disconnected(libusb_device* device) {
+    std::string device_address = get_device_address(device);
 
-        std::unique_lock<std::mutex> lock(device_poll_mutex);
-        if (device_poll_cv.wait_for(lock, 500ms, []() { return terminate_device_poll_thread; })) {
-            return;
+    LOG(INFO) << "device disconnected: " << device_address;
+    std::unique_lock<std::mutex> lock(usb_handles_mutex);
+    auto it = usb_handles.find(device_address);
+    if (it != usb_handles.end()) {
+        if (!it->second->device_handle) {
+            // If the handle is null, we were never able to open the device.
+            unregister_usb_transport(it->second.get());
         }
+        usb_handles.erase(it);
     }
 }
 
+static int hotplug_callback(libusb_context*, libusb_device* device, libusb_hotplug_event event,
+                            void*) {
+    if (event == LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) {
+        device_connected(device);
+    } else if (event == LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT) {
+        device_disconnected(device);
+    }
+    return 0;
+}
+
 void usb_init() {
     LOG(DEBUG) << "initializing libusb...";
     int rc = libusb_init(nullptr);
@@ -405,6 +442,24 @@
         LOG(FATAL) << "failed to initialize libusb: " << libusb_error_name(rc);
     }
 
+    // Register the hotplug callback.
+    rc = libusb_hotplug_register_callback(
+        nullptr, static_cast<libusb_hotplug_event>(LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED |
+                                                   LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT),
+        LIBUSB_HOTPLUG_ENUMERATE, LIBUSB_HOTPLUG_MATCH_ANY, LIBUSB_HOTPLUG_MATCH_ANY,
+        LIBUSB_CLASS_PER_INTERFACE, hotplug_callback, nullptr, &hotplug_handle);
+
+    if (rc != LIBUSB_SUCCESS) {
+        LOG(FATAL) << "failed to register libusb hotplug callback";
+    }
+
+    // Wait for all of the connecting devices to finish.
+    while (connecting_devices != 0) {
+        std::this_thread::sleep_for(10ms);
+    }
+
+    adb_notify_device_scan_complete();
+
     // Spawn a thread for libusb_handle_events.
     std::thread([]() {
         adb_thread_setname("libusb");
@@ -412,24 +467,10 @@
             libusb_handle_events(nullptr);
         }
     }).detach();
-
-    // Spawn a thread to do device enumeration.
-    // TODO: Use libusb_hotplug_* instead?
-    std::unique_lock<std::mutex> lock(device_poll_mutex);
-    device_poll_thread = new std::thread(poll_for_devices);
 }
 
 void usb_cleanup() {
-    {
-        std::unique_lock<std::mutex> lock(device_poll_mutex);
-        terminate_device_poll_thread = true;
-
-        if (!device_poll_thread) {
-            return;
-        }
-    }
-    device_poll_cv.notify_all();
-    device_poll_thread->join();
+    libusb_hotplug_deregister_callback(nullptr, hotplug_handle);
 }
 
 // Dispatch a libusb transfer, unlock |device_lock|, and then wait for the result.
diff --git a/base/Android.bp b/base/Android.bp
index 81b96db..b636dc3 100644
--- a/base/Android.bp
+++ b/base/Android.bp
@@ -53,7 +53,6 @@
 
     header_libs: [
         "libbase_headers",
-        "libutils_headers",
     ],
     export_header_lib_headers: ["libbase_headers"],
 
diff --git a/base/file.cpp b/base/file.cpp
index 7fbebc5..a2f2887 100644
--- a/base/file.cpp
+++ b/base/file.cpp
@@ -32,13 +32,14 @@
 #include "android-base/macros.h"  // For TEMP_FAILURE_RETRY on Darwin.
 #include "android-base/unique_fd.h"
 #include "android-base/utf8.h"
-#include "utils/Compat.h"
 
 #if defined(__APPLE__)
 #include <mach-o/dyld.h>
 #endif
 #if defined(_WIN32)
 #include <windows.h>
+#define O_CLOEXEC O_NOINHERIT
+#define O_NOFOLLOW 0
 #endif
 
 namespace android {
@@ -133,7 +134,7 @@
                        bool follow_symlinks) {
   int flags = O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_BINARY |
               (follow_symlinks ? 0 : O_NOFOLLOW);
-  android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path.c_str(), flags, DEFFILEMODE)));
+  android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path.c_str(), flags, 0666)));
   if (fd == -1) {
     return false;
   }
diff --git a/fs_mgr/fs_mgr_avb.cpp b/fs_mgr/fs_mgr_avb.cpp
index 2b32201..6618003 100644
--- a/fs_mgr/fs_mgr_avb.cpp
+++ b/fs_mgr/fs_mgr_avb.cpp
@@ -16,15 +16,14 @@
 
 #include "fs_mgr_avb.h"
 
-#include <errno.h>
 #include <fcntl.h>
-#include <inttypes.h>
 #include <libgen.h>
-#include <stdio.h>
 #include <string.h>
-#include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <sys/types.h>
-#include <unistd.h>
+
+#include <sstream>
+#include <string>
 #include <vector>
 
 #include <android-base/file.h>
@@ -33,11 +32,7 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
-#include <cutils/properties.h>
 #include <libavb/libavb.h>
-#include <openssl/sha.h>
-#include <sys/ioctl.h>
-#include <utils/Compat.h>
 
 #include "fs_mgr.h"
 #include "fs_mgr_priv.h"
@@ -45,48 +40,6 @@
 #include "fs_mgr_priv_dm_ioctl.h"
 #include "fs_mgr_priv_sha.h"
 
-/* The format of dm-verity construction parameters:
- *     <version> <dev> <hash_dev> <data_block_size> <hash_block_size>
- *     <num_data_blocks> <hash_start_block> <algorithm> <digest> <salt>
- */
-#define VERITY_TABLE_FORMAT \
-    "%u %s %s %u %u "       \
-    "%" PRIu64 " %" PRIu64 " %s %s %s "
-
-#define VERITY_TABLE_PARAMS(hashtree_desc, blk_device, digest, salt)                        \
-    hashtree_desc.dm_verity_version, blk_device, blk_device, hashtree_desc.data_block_size, \
-        hashtree_desc.hash_block_size,                                                      \
-        hashtree_desc.image_size / hashtree_desc.data_block_size,  /* num_data_blocks. */   \
-        hashtree_desc.tree_offset / hashtree_desc.hash_block_size, /* hash_start_block. */  \
-        (char*)hashtree_desc.hash_algorithm, digest, salt
-
-#define VERITY_TABLE_OPT_RESTART "restart_on_corruption"
-#define VERITY_TABLE_OPT_IGNZERO "ignore_zero_blocks"
-
-/* The default format of dm-verity optional parameters:
- *     <#opt_params> ignore_zero_blocks restart_on_corruption
- */
-#define VERITY_TABLE_OPT_DEFAULT_FORMAT "2 %s %s"
-#define VERITY_TABLE_OPT_DEFAULT_PARAMS VERITY_TABLE_OPT_IGNZERO, VERITY_TABLE_OPT_RESTART
-
-/* The FEC (forward error correction) format of dm-verity optional parameters:
- *     <#opt_params> use_fec_from_device <fec_dev>
- *     fec_roots <num> fec_blocks <num> fec_start <offset>
- *     ignore_zero_blocks restart_on_corruption
- */
-#define VERITY_TABLE_OPT_FEC_FORMAT \
-    "10 use_fec_from_device %s fec_roots %u fec_blocks %" PRIu64 " fec_start %" PRIu64 " %s %s"
-
-/* Note that fec_blocks is the size that FEC covers, *not* the
- * size of the FEC data. Since we use FEC for everything up until
- * the FEC data, it's the same as the offset (fec_start).
- */
-#define VERITY_TABLE_OPT_FEC_PARAMS(hashtree_desc, blk_device)                     \
-    blk_device, hashtree_desc.fec_num_roots,                                       \
-        hashtree_desc.fec_offset / hashtree_desc.data_block_size, /* fec_blocks */ \
-        hashtree_desc.fec_offset / hashtree_desc.data_block_size, /* fec_start */  \
-        VERITY_TABLE_OPT_IGNZERO, VERITY_TABLE_OPT_RESTART
-
 static inline bool nibble_value(const char& c, uint8_t* value) {
     FS_MGR_CHECK(value != nullptr);
 
@@ -280,10 +233,81 @@
     return true;
 }
 
-static bool hashtree_load_verity_table(struct dm_ioctl* io, const std::string& dm_device_name,
-                                       int fd, const std::string& blk_device,
-                                       const AvbHashtreeDescriptor& hashtree_desc,
-                                       const std::string& salt, const std::string& root_digest) {
+// Constructs dm-verity arguments for sending DM_TABLE_LOAD ioctl to kernel.
+// See the following link for more details:
+// https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity
+static std::string construct_verity_table(const AvbHashtreeDescriptor& hashtree_desc,
+                                          const std::string& salt, const std::string& root_digest,
+                                          const std::string& blk_device) {
+    // Loads androidboot.veritymode from kernel cmdline.
+    std::string verity_mode;
+    if (!fs_mgr_get_boot_config("veritymode", &verity_mode)) {
+        verity_mode = "enforcing";  // Defaults to enforcing when it's absent.
+    }
+
+    // Converts veritymode to the format used in kernel.
+    std::string dm_verity_mode;
+    if (verity_mode == "enforcing") {
+        dm_verity_mode = "restart_on_corruption";
+    } else if (verity_mode == "logging") {
+        dm_verity_mode = "ignore_corruption";
+    } else if (verity_mode != "eio") {  // Default dm_verity_mode is eio.
+        LERROR << "Unknown androidboot.veritymode: " << verity_mode;
+        return "";
+    }
+
+    // dm-verity construction parameters:
+    //   <version> <dev> <hash_dev>
+    //   <data_block_size> <hash_block_size>
+    //   <num_data_blocks> <hash_start_block>
+    //   <algorithm> <digest> <salt>
+    //   [<#opt_params> <opt_params>]
+    std::ostringstream verity_table;
+    verity_table << hashtree_desc.dm_verity_version << " " << blk_device << " " << blk_device << " "
+                 << hashtree_desc.data_block_size << " " << hashtree_desc.hash_block_size << " "
+                 << hashtree_desc.image_size / hashtree_desc.data_block_size << " "
+                 << hashtree_desc.tree_offset / hashtree_desc.hash_block_size << " "
+                 << hashtree_desc.hash_algorithm << " " << root_digest << " " << salt;
+
+    // Continued from the above optional parameters:
+    //   [<#opt_params> <opt_params>]
+    int optional_argc = 0;
+    std::ostringstream optional_args;
+
+    // dm-verity optional parameters for FEC (forward error correction):
+    //   use_fec_from_device <fec_dev>
+    //   fec_roots <num>
+    //   fec_blocks <num>
+    //   fec_start <offset>
+    if (hashtree_desc.fec_size > 0) {
+        // Note that fec_blocks is the size that FEC covers, *NOT* the
+        // size of the FEC data. Since we use FEC for everything up until
+        // the FEC data, it's the same as the offset (fec_start).
+        optional_argc += 8;
+        // clang-format off
+        optional_args << "use_fec_from_device " << blk_device
+                      << " fec_roots " << hashtree_desc.fec_num_roots
+                      << " fec_blocks " << hashtree_desc.fec_offset / hashtree_desc.data_block_size
+                      << " fec_start " << hashtree_desc.fec_offset / hashtree_desc.data_block_size
+                      << " ";
+        // clang-format on
+    }
+
+    if (!dm_verity_mode.empty()) {
+        optional_argc += 1;
+        optional_args << dm_verity_mode << " ";
+    }
+
+    // Always use ignore_zero_blocks.
+    optional_argc += 1;
+    optional_args << "ignore_zero_blocks";
+
+    verity_table << " " << optional_argc << " " << optional_args.str();
+    return verity_table.str();
+}
+
+static bool load_verity_table(struct dm_ioctl* io, const std::string& dm_device_name, int fd,
+                              uint64_t image_size, const std::string& verity_table) {
     fs_mgr_verity_ioctl_init(io, dm_device_name, DM_STATUS_TABLE_FLAG);
 
     // The buffer consists of [dm_ioctl][dm_target_spec][verity_params].
@@ -294,35 +318,25 @@
     io->target_count = 1;
     dm_target->status = 0;
     dm_target->sector_start = 0;
-    dm_target->length = hashtree_desc.image_size / 512;
+    dm_target->length = image_size / 512;
     strcpy(dm_target->target_type, "verity");
 
     // Builds the verity params.
     char* verity_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
     size_t bufsize = DM_BUF_SIZE - (verity_params - buffer);
 
-    int res = 0;
-    if (hashtree_desc.fec_size > 0) {
-        res = snprintf(verity_params, bufsize, VERITY_TABLE_FORMAT VERITY_TABLE_OPT_FEC_FORMAT,
-                       VERITY_TABLE_PARAMS(hashtree_desc, blk_device.c_str(), root_digest.c_str(),
-                                           salt.c_str()),
-                       VERITY_TABLE_OPT_FEC_PARAMS(hashtree_desc, blk_device.c_str()));
-    } else {
-        res = snprintf(verity_params, bufsize, VERITY_TABLE_FORMAT VERITY_TABLE_OPT_DEFAULT_FORMAT,
-                       VERITY_TABLE_PARAMS(hashtree_desc, blk_device.c_str(), root_digest.c_str(),
-                                           salt.c_str()),
-                       VERITY_TABLE_OPT_DEFAULT_PARAMS);
-    }
+    LINFO << "Loading verity table: '" << verity_table << "'";
 
-    if (res < 0 || (size_t)res >= bufsize) {
-        LERROR << "Error building verity table; insufficient buffer size?";
+    // Copies verity_table to verity_params (including the terminating null byte).
+    if (verity_table.size() > bufsize - 1) {
+        LERROR << "Verity table size too large: " << verity_table.size()
+               << " (max allowable size: " << bufsize - 1 << ")";
         return false;
     }
-
-    LINFO << "Loading verity table: '" << verity_params << "'";
+    memcpy(verity_params, verity_table.c_str(), verity_table.size() + 1);
 
     // Sets ext target boundary.
-    verity_params += strlen(verity_params) + 1;
+    verity_params += verity_table.size() + 1;
     verity_params = (char*)(((unsigned long)verity_params + 7) & ~7);
     dm_target->next = verity_params - buffer;
 
@@ -362,9 +376,15 @@
         return false;
     }
 
+    std::string verity_table =
+        construct_verity_table(hashtree_desc, salt, root_digest, fstab_entry->blk_device);
+    if (verity_table.empty()) {
+        LERROR << "Failed to construct verity table.";
+        return false;
+    }
+
     // Loads the verity mapping table.
-    if (!hashtree_load_verity_table(io, mount_point, fd, std::string(fstab_entry->blk_device),
-                                    hashtree_desc, salt, root_digest)) {
+    if (!load_verity_table(io, mount_point, fd, hashtree_desc.image_size, verity_table)) {
         LERROR << "Couldn't load verity table!";
         return false;
     }
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 64d1d2f..e9ef9cc 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -530,6 +530,7 @@
         "  process    — Display PID only.\n"
         "  raw        — Display the raw log message, with no other metadata fields.\n"
         "  tag        — Display the priority/tag only.\n"
+        "  thread     — Display priority, PID and TID of process issuing the message.\n"
         "  threadtime — Display the date, invocation time, priority, tag, and the PID\n"
         "               and TID of the thread issuing the message. (the default format).\n"
         "  time       — Display the date, invocation time, priority/tag, and PID of the\n"
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index d9ec081..fbed83b 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -605,6 +605,33 @@
     }
 };
 
+// Determine if watermark is within pruneMargin + 1s from the end of the list,
+// the caller will use this result to set an internal busy flag indicating
+// the prune operation could not be completed because a reader is blocking
+// the request.
+bool LogBuffer::isBusy(log_time watermark) {
+    LogBufferElementCollection::iterator ei = mLogElements.end();
+    --ei;
+    return watermark < ((*ei)->getRealTime() - pruneMargin - log_time(1, 0));
+}
+
+// If the selected reader is blocking our pruning progress, decide on
+// what kind of mitigation is necessary to unblock the situation.
+void LogBuffer::kickMe(LogTimeEntry* me, log_id_t id, unsigned long pruneRows) {
+    if (stats.sizes(id) > (2 * log_buffer_size(id))) {  // +100%
+        // A misbehaving or slow reader has its connection
+        // dropped if we hit too much memory pressure.
+        me->release_Locked();
+    } else if (me->mTimeout.tv_sec || me->mTimeout.tv_nsec) {
+        // Allow a blocked WRAP timeout reader to
+        // trigger and start reporting the log data.
+        me->triggerReader_Locked();
+    } else {
+        // tell slow reader to skip entries to catch up
+        me->triggerSkip_Locked(id, pruneRows);
+    }
+}
+
 // prune "pruneRows" of type "id" from the buffer.
 //
 // This garbage collection task is used to expire log entries. It is called to
@@ -695,12 +722,8 @@
             }
 
             if (oldest && (watermark <= element->getRealTime())) {
-                busy = true;
-                if (oldest->mTimeout.tv_sec || oldest->mTimeout.tv_nsec) {
-                    oldest->triggerReader_Locked();
-                } else {
-                    oldest->triggerSkip_Locked(id, pruneRows);
-                }
+                busy = isBusy(watermark);
+                if (busy) kickMe(oldest, id, pruneRows);
                 break;
             }
 
@@ -787,10 +810,8 @@
             LogBufferElement* element = *it;
 
             if (oldest && (watermark <= element->getRealTime())) {
-                busy = true;
-                if (oldest->mTimeout.tv_sec || oldest->mTimeout.tv_nsec) {
-                    oldest->triggerReader_Locked();
-                }
+                busy = isBusy(watermark);
+                // Do not let chatty eliding trigger any reader mitigation
                 break;
             }
 
@@ -941,19 +962,8 @@
         }
 
         if (oldest && (watermark <= element->getRealTime())) {
-            busy = true;
-            if (whitelist) {
-                break;
-            }
-
-            if (stats.sizes(id) > (2 * log_buffer_size(id))) {
-                // kick a misbehaving log reader client off the island
-                oldest->release_Locked();
-            } else if (oldest->mTimeout.tv_sec || oldest->mTimeout.tv_nsec) {
-                oldest->triggerReader_Locked();
-            } else {
-                oldest->triggerSkip_Locked(id, pruneRows);
-            }
+            busy = isBusy(watermark);
+            if (!whitelist && busy) kickMe(oldest, id, pruneRows);
             break;
         }
 
@@ -985,15 +995,8 @@
             }
 
             if (oldest && (watermark <= element->getRealTime())) {
-                busy = true;
-                if (stats.sizes(id) > (2 * log_buffer_size(id))) {
-                    // kick a misbehaving log reader client off the island
-                    oldest->release_Locked();
-                } else if (oldest->mTimeout.tv_sec || oldest->mTimeout.tv_nsec) {
-                    oldest->triggerReader_Locked();
-                } else {
-                    oldest->triggerSkip_Locked(id, pruneRows);
-                }
+                busy = isBusy(watermark);
+                if (busy) kickMe(oldest, id, pruneRows);
                 break;
             }
 
@@ -1139,10 +1142,6 @@
             continue;
         }
 
-        if (element->getRealTime() <= start) {
-            continue;
-        }
-
         // NB: calling out to another object with wrlock() held (safe)
         if (filter) {
             int ret = (*filter)(element, arg);
@@ -1169,11 +1168,10 @@
         unlock();
 
         // range locking in LastLogTimes looks after us
-        max = element->flushTo(reader, this, privileged, sameTid);
+        log_time next = element->flushTo(reader, this, privileged, sameTid);
 
-        if (max == element->FLUSH_ERROR) {
-            return max;
-        }
+        if (next == element->FLUSH_ERROR) return next;
+        if (next > max) max = next;
 
         skip = maxSkip;
         rdlock();
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index f0d6fcb..0942987 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -184,6 +184,9 @@
     static const log_time pruneMargin;
 
     void maybePrune(log_id_t id);
+    bool isBusy(log_time watermark);
+    void kickMe(LogTimeEntry* me, log_id_t id, unsigned long pruneRows);
+
     bool prune(log_id_t id, unsigned long pruneRows, uid_t uid = AID_ROOT);
     LogBufferElementCollection::iterator erase(
         LogBufferElementCollection::iterator it, bool coalesce = false);