From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 25 Mar 2022 23:38:24 +0000 (-0700)
Subject: Merge branch 'ns/core-fsyncmethod'
X-Git-Tag: v2.36.0-rc0~35
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eb804cd405618ef78b772072685c39392aea4ac1;p=thirdparty%2Fgit.git

Merge branch 'ns/core-fsyncmethod'

Replace core.fsyncObjectFiles with two new configuration variables,
core.fsync and core.fsyncMethod.

* ns/core-fsyncmethod:
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
---

eb804cd405618ef78b772072685c39392aea4ac1
diff --cc git-compat-util.h
index e50e2fafae,00356476a9..0892e209a2
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@@ -1262,7 -1265,36 +1256,31 @@@ extern int BUG_exit_code
  __attribute__((format (printf, 3, 4))) NORETURN
  void BUG_fl(const char *file, int line, const char *fmt, ...);
  #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
 -#else
 -__attribute__((format (printf, 1, 2))) NORETURN
 -void BUG(const char *fmt, ...);
 -#endif
  
+ #ifdef __APPLE__
+ #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_WRITEOUT_ONLY
+ #else
+ #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_FSYNC
+ #endif
+ 
+ enum fsync_action {
+ 	FSYNC_WRITEOUT_ONLY,
+ 	FSYNC_HARDWARE_FLUSH
+ };
+ 
+ /*
+  * Issues an fsync against the specified file according to the specified mode.
+  *
+  * FSYNC_WRITEOUT_ONLY attempts to use interfaces available on some operating
+  * systems to flush the OS cache without issuing a flush command to the storage
+  * controller. If those interfaces are unavailable, the function fails with
+  * ENOSYS.
+  *
+  * FSYNC_HARDWARE_FLUSH does an OS writeout and hardware flush to ensure that
+  * changes are durable. It is not expected to fail.
+  */
+ int git_fsync(int fd, enum fsync_action action);
+ 
  /*
   * Preserves errno, prints a message, but gives no warning for ENOENT.
   * Returns 0 on success, which includes trying to unlink an object that does