use a subdirectory of annex.dbdir

This allows annex.dbdir to be set globally or always set to the same
value when needed. Each repository uses a subdirectory of it.

Sponsored-by: Dartmouth College's Datalad project

Annex/Perms.hs

@@ -114,7 +114,7 @@ createAnnexDirectory dir = do
 	top <- parentDir <$> fromRepo gitAnnexDir
 	tops <- annexDbDir <$> Annex.getGitConfig >>= return . \case
 		Nothing -> [top]
-		Just dbdir -> [top, parentDir dbdir]
+		Just dbdir -> [top, parentDir (parentDir dbdir)]
 	createDirectoryUnder' tops dir createdir
   where
 	createdir p = do

Database/Init.hs

@@ -38,7 +38,7 @@ initDb db migration = do
 	gc <- Annex.getGitConfig
 	top <- parentDir <$> fromRepo gitAnnexDir
 	let tops = case annexDbDir gc of
-		Just topdbdir -> [top, parentDir topdbdir]
+		Just topdbdir -> [top, parentDir (parentDir topdbdir)]
 		Nothing -> [top]
 	liftIO $ do
 		createDirectoryUnder tops tmpdbdir

Types/GitConfig.hs

@@ -53,6 +53,7 @@ import Control.Concurrent.STM
 import qualified Data.Set as S
 import qualified Data.Map as M
 import qualified Data.ByteString as B
+import qualified System.FilePath.ByteString as P
 
 -- | A configurable value, that may not be fully determined yet because
 -- the global git config has not yet been loaded.
@@ -213,7 +214,8 @@ extractGitConfig configsource r = GitConfig
 	, annexPidLock = getbool (annexConfig "pidlock") False
 	, annexPidLockTimeout = Seconds $ fromMaybe 300 $
 		getmayberead (annexConfig "pidlocktimeout")
-	, annexDbDir = toRawFilePath <$> getmaybe (annexConfig "dbdir")
+	, annexDbDir = (\d -> toRawFilePath d P.</> fromUUID hereuuid)
+		<$> getmaybe (annexConfig "dbdir")
 	, annexAddUnlocked = configurable Nothing $
 		fmap Just $ getmaybe (annexConfig "addunlocked")
 	, annexSecureHashesOnly = getbool (annexConfig "securehashesonly") False

doc/bugs/crippled_filesystem__58___SQLite3_returned_ErrorBusy/comment_12_918ed48f23dfdc1fc95e3df9526b489c._comment

@@ -3,11 +3,14 @@
  subject="""comment 12"""
  date="2022-08-12T17:07:51Z"
  content="""
-annex.dbdir is now implemented.
+annex.dbdir is now implemented. Note that it can safely be set to the same
+path in several repositories. If all your repositories were on cifs,
+you could even set it globally.
 
 This issue remains open because `git-annex init` ought to probe to
 determine when sqlite cannot be used on the repository's filesystem.
 I don't think it could itself set annex.dbdir to work around the
-problem, because what would it set it to? But it could explain the problem
-to the user and suggest that they set it.
+problem, because what would it set it to? Maybe
+`~/.cache/git-annex/something`? Seems better for it to explain the
+problem to the user and suggest that they set it.
 """]]

doc/git-annex.mdwn

@@ -1237,6 +1237,10 @@ repository, using [[git-annex-config]]. See its man page for a list.)
   that sqlite needs, and setting this to a directory on another filesystem
   can work around such a problem.
 
+  This can safely be set to the same directory in the configuration of
+  multiple repositories; each repository will use a subdirectory for its
+  sqlite database.
+
 * `annex.cachecreds`
 
   When "true" (the default), git-annex will cache credentials used to