Merge df1ba101419729aafa382d970ee605e2a6273e26 into db2c57ae9eebdb75c58cd165ac929919969c19a9

doc/files.md

@@ -16,6 +16,8 @@
 
 - [Legacy subdirectories and files](#legacy-subdirectories-and-files)
 
+- [Filesystem recommendations](#filesystem-recommendations)
+
 - [Notes](#notes)
 
 ## Data directory location
@@ -123,6 +125,12 @@ Path           | Description | Repository notes
 `addr.dat`     | Peer IP address BDB database; replaced by `peers.dat` in [0.7.0](https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.7.0.md) | [PR #1198](https://github.com/bitcoin/bitcoin/pull/1198), [`928d3a01`](https://github.com/bitcoin/bitcoin/commit/928d3a011cc66c7f907c4d053f674ea77dc611cc)
 `onion_private_key` | Cached Tor onion service private key for `-listenonion` option. Was used for Tor v2 services; replaced by `onion_v3_private_key` in [0.21.0](https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.21.0.md) | [PR #19954](https://github.com/bitcoin/bitcoin/pull/19954)
 
+## Filesystem recommendations
+
+When choosing a filesystem for the data directory (`datadir`) or blocks directory (`blocksdir`), some filesystems should be avoided:
+
+- **macOS**: The exFAT filesystem should not be used. There have been multiple reports of database and other corruption when using exFAT on macOS for Bitcoin Core. This appears to be due to filesystem-level issues with exFAT on the macOS operating system. See [Issue #31454](https://github.com/bitcoin/bitcoin/issues/31454) for more details.
+
 ## Notes
 
 <a name="note1">1</a>. The `/` (slash, U+002F) is used as the platform-independent path component separator in this document.

src/common/init.cpp

@@ -6,8 +6,10 @@
 #include <common/args.h>
 #include <common/init.h>
 #include <logging.h>
+#include <node/interface_ui.h>
 #include <tinyformat.h>
 #include <util/fs.h>
+#include <util/fs_helpers.h>
 #include <util/translation.h>
 
 #include <algorithm>
@@ -61,7 +63,48 @@ std::optional<ConfigError> InitConfig(ArgsManager& args, SettingsAbortFn setting
         if (!fs::exists(net_path)) {
             fs::create_directories(net_path / "wallets");
         }
+#ifdef __APPLE__
+        struct PathCheck {
+            fs::path path;
+            std::string_view description;
+        };
 
+        std::array<PathCheck, 2> paths{{
+            {args.GetDataDirNet(), "data directory"},
+            {args.GetBlocksDirPath(), "blocks directory"}
+        }};
+
+        std::vector<std::string> exfat_paths;
+        std::vector<std::string> error_paths;
+
+        for (const auto& check : paths) {
+            FSType fs_type = GetFilesystemType(check.path);
+            switch(fs_type) {
+                case FSType::EXFAT:
+                    exfat_paths.push_back(strprintf("%s (\"%s\")",
+                        check.description,
+                        fs::PathToString(check.path)));
+                    break;
+                case FSType::ERROR:
+                    error_paths.push_back(strprintf("%s (\"%s\")",
+                        check.description,
+                        fs::PathToString(check.path)));
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        if (!exfat_paths.empty()) {
+            InitWarning(strprintf(_("The following paths are on exFAT which is known to have intermittent corruption problems on MacOS: %s. "
+                "See https://github.com/bitcoin/bitcoin/blob/master/doc/files.md#filesystem-recommendations for more information."),
+                util::Join(exfat_paths, ", ")));
+        }
+
+        if (!error_paths.empty()) {
+            LogInfo("Failed to detect filesystem type for: %s\n", util::Join(error_paths, ", "));
+        }
+#endif
         // Show an error or warn/log if there is a bitcoin.conf file in the
         // datadir that is being ignored.
         const fs::path base_config_path = base_path / BITCOIN_CONF_FILENAME;

src/util/fs_helpers.cpp

@@ -41,6 +41,11 @@
 #include <shlobj.h> /* For SHGetSpecialFolderPathW */
 #endif // WIN32
 
+#ifdef __APPLE__
+#include <sys/mount.h>
+#include <sys/param.h>
+#endif
+
 /** Mutex to protect dir_locks. */
 static GlobalMutex cs_dir_locks;
 /** A map that contains all the currently held directory locks. After
@@ -309,3 +314,17 @@ std::optional<fs::perms> InterpretPermString(const std::string& s)
         return std::nullopt;
     }
 }
+
+#ifdef __APPLE__
+FSType GetFilesystemType(const fs::path& path) {
+    struct statfs fs_info;
+    if (statfs(path.c_str(), &fs_info) != 0) {
+        return FSType::ERROR;
+    }
+
+    if (strcmp(fs_info.f_fstypename, "exfat") == 0) {
+        return FSType::EXFAT;
+    }
+    return FSType::OTHER;
+}
+#endif

src/util/fs_helpers.h

@@ -14,6 +14,23 @@
 #include <limits>
 #include <optional>
 
+#ifdef __APPLE__
+enum class FSType {
+    EXFAT,
+    OTHER,
+    ERROR
+};
+
+/**
+ * Detect filesystem type for a given path.
+ * Currently identifies exFAT filesystems which cause issues on MacOS.
+ *
+ * @param[in] path The directory path to check
+ * @return FSType enum indicating the filesystem type
+ */
+FSType GetFilesystemType(const fs::path& path);
+#endif
+
 /**
  * Ensure file contents are fully committed to disk, using a platform-specific
  * feature analogous to fsync().