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author | Junio C Hamano <gitster@pobox.com> | 2022-03-15 23:30:37 +0300 |
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committer | Junio C Hamano <gitster@pobox.com> | 2022-03-15 23:30:37 +0300 |
commit | 00997924001f3d8a07510613ab44d16c0a9b2883 (patch) | |
tree | 7cb0ae32b7f4b80ee6538774596f3cfdc4239f3f /Documentation | |
parent | 1a4874565fa3b6668042216189551b98b4dc0b1b (diff) | |
parent | b9f5d0358d2e882d47f496c1a5589f6cebc25578 (diff) |
Merge branch 'ns/core-fsyncmethod' into ps/fsync-refs
* 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
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/config/core.txt | 58 |
1 files changed, 54 insertions, 4 deletions
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index c04f62a54a..9a3ad71e9e 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -547,13 +547,63 @@ core.whitespace:: is relevant for `indent-with-non-tab` and when Git fixes `tab-in-indent` errors. The default tab width is 8. Allowed values are 1 to 63. +core.fsync:: + A comma-separated list of components of the repository that + should be hardened via the core.fsyncMethod when created or + modified. You can disable hardening of any component by + prefixing it with a '-'. Items that are not hardened may be + lost in the event of an unclean system shutdown. Unless you + have special requirements, it is recommended that you leave + this option empty or pick one of `committed`, `added`, + or `all`. ++ +When this configuration is encountered, the set of components starts with +the platform default value, disabled components are removed, and additional +components are added. `none` resets the state so that the platform default +is ignored. ++ +The empty string resets the fsync configuration to the platform +default. The default on most platforms is equivalent to +`core.fsync=committed,-loose-object`, which has good performance, +but risks losing recent work in the event of an unclean system shutdown. ++ +* `none` clears the set of fsynced components. +* `loose-object` hardens objects added to the repo in loose-object form. +* `pack` hardens objects added to the repo in packfile form. +* `pack-metadata` hardens packfile bitmaps and indexes. +* `commit-graph` hardens the commit graph file. +* `index` hardens the index when it is modified. +* `objects` is an aggregate option that is equivalent to + `loose-object,pack`. +* `derived-metadata` is an aggregate option that is equivalent to + `pack-metadata,commit-graph`. +* `committed` is an aggregate option that is currently equivalent to + `objects`. This mode sacrifices some performance to ensure that work + that is committed to the repository with `git commit` or similar commands + is hardened. +* `added` is an aggregate option that is currently equivalent to + `committed,index`. This mode sacrifices additional performance to + ensure that the results of commands like `git add` and similar operations + are hardened. +* `all` is an aggregate option that syncs all individual components above. + +core.fsyncMethod:: + A value indicating the strategy Git will use to harden repository data + using fsync and related primitives. ++ +* `fsync` uses the fsync() system call or platform equivalents. +* `writeout-only` issues pagecache writeback requests, but depending on the + filesystem and storage hardware, data added to the repository may not be + durable in the event of a system crash. This is the default mode on macOS. + core.fsyncObjectFiles:: This boolean will enable 'fsync()' when writing object files. + This setting is deprecated. Use core.fsync instead. + -This is a total waste of time and effort on a filesystem that orders -data writes properly, but can be useful for filesystems that do not use -journalling (traditional UNIX filesystems) or that only journal metadata -and not file contents (OS X's HFS+, or Linux ext3 with "data=writeback"). +This setting affects data added to the Git repository in loose-object +form. When set to true, Git will issue an fsync or similar system call +to flush caches so that loose-objects remain consistent in the face +of a unclean system shutdown. core.preloadIndex:: Enable parallel index preload for operations like 'git diff' |