Dropping an object with drop --unused or dropunused will mark it as
dead, preventing fsck --all from complaining about it after it's been
dropped from all repositories.
If another repository still has a copy, it won't be treated as dead
until it's also dropped from there.
The drop has to use --unused, can't be --key or something else, because
this indicates that the user has recently ran git-annex unused. If it
checked the unused log on every drop, bad things would happen when the
unused log was out of date, eg a file used to be unused but then got
re-added. Marking such a file as dead could be confusing. When the user
uses --unused/dropunused, they must consider the unused information to be
up-to-date.
The particular workflow this enables is:
git annex add foo
git annex unannex foo
git annex unused
git annex drop --unused / dropunused
git annex fsck --all # no warnings
The docs for git-annex unannex say to use git-annex unused and dropunused,
so the user should be pointed in this direction when they want to undo an
accidental add.
Sponsored-by: Brock Spratlen on Patreon
Freeze first sets the file perms, and then runs
freezecontent-command. Thaw runs thawcontent-command before
restoring file permissions. This is in case the freeze command
prevents changing file perms, as eg setting a file immutable does.
Also, changing file perms tends to mess up previously set ACLs.
git-annex init's probe for crippled filesystem uses them, so if file perms
don't work, but freezecontent-command manages to prevent write to a file,
it won't treat the filesystem as crippled.
When the the filesystem has been probed as crippled, the hooks are not
used, because there seems to be no point then; git-annex won't be relying
on locking annex objects down. Also, this avoids them being run when the
file perms have not been changed, in case they somehow rely on
git-annex's setting of the file perms in order to work.
Sponsored-by: Dartmouth College's Datalad project