diff options
Diffstat (limited to 'pkgs')
| -rw-r--r-- | pkgs/populate/default.nix | 55 |
1 files changed, 42 insertions, 13 deletions
diff --git a/pkgs/populate/default.nix b/pkgs/populate/default.nix index 7130570..71844cb 100644 --- a/pkgs/populate/default.nix +++ b/pkgs/populate/default.nix @@ -65,12 +65,14 @@ let # Shell code that removes what's at path, a shell word, with everything # below it, also what isn't writable. A symlink gets removed itself, - # instead of followed. + # instead of followed. Only directories get made writable, which is what + # removing what's in them needs: a file may be a hard link to one + # elsewhere, which shares its mode. removeTree = path: /* sh */ '' if test -L ${path}; then rm ${path} elif test -e ${path}; then - chmod -R u+w ${path} + find ${path} -type d -exec chmod u+w {} + rm -fR ${path} fi ''; @@ -79,8 +81,7 @@ let # that aren't named names. find, unlike a loop reading names, copes with # every name, e.g. ones that end in blanks or contain newlines. Entries of # populate's own state get removed like removeTree does. Entries of the - # target directory get removed without making them writable first, which - # would change files elsewhere that are hard links to files therein; for + # target directory get removed without making anything writable first; for # those, log is a shell word for the directory's name in the line that # gets printed for each entry. removeOthers = { dir, names, log ? null }: /* sh */ '' @@ -101,7 +102,8 @@ let if test -L "$path"; then rm "$path" else - chmod -R u+w "$path" + # Escaped, or the outer find takes the braces for its own. + find "$path" -type d -exec chmod u+w {\} + rm -fR "$path" fi ''} @@ -124,7 +126,8 @@ let # it points into the store, like the links populate puts there itself. removeForeignLink = path: /* sh */ '' if test -L ${quote path}; then - case $(readlink ${quote path}) in + # Resolved, so a link like /nix/store/../.. doesn't count. + case $(readlink -f ${quote path}) in /nix/store/*) ;; *) ${removeLink path} @@ -217,7 +220,9 @@ let fi ${optionalString force /* sh */ '' mkdir -vp ${quote (dirOf sentinelFile)} >&2 - touch ${quote sentinelFile} + if ! test -e ${quote sentinelFile}; then + touch ${quote sentinelFile} + fi ''} if ! test -e ${quote sentinelFile}; then >&2 printf 'error: missing sentinel file: %s\n' ${quote ( @@ -371,6 +376,13 @@ let removeWork = removeTree (quote "${dir}/work"); in /* sh */ '' ( + # Writes the key $1 to a new file, which then replaces the key, so + # nothing at its place gets written through, e.g. a symlink. + write_key() { + key_file=$(mktemp ${quote "${dir}/key"}.XXXXXX) + printf '%s\n' "$1" > "$key_file" + mv -f "$key_file" ${quote "${dir}/key"} + } original=$(readlink -f ${quote "${dir}/original"}) path=$(printf '%s\n' "$original" | cut -d/ -f1-4) subdir=''${original#"$path"} @@ -417,7 +429,7 @@ let ${removeForeignLink targetPath} rm -fR ${quote targetPath} mv ${quote "${dir}/work"} ${quote targetPath} - printf '%s\n' "$key" > ${quote "${dir}/key"} + write_key "$key" fi ${optionalString rewriteLock /* sh */ '' ${overrideArgs name} @@ -450,7 +462,7 @@ let ${removeWork} nix-store --realise "$result" \ --add-root ${quote "${dir}/result"} --indirect >/dev/null - printf '%s\n' "$key" > ${quote "${dir}/key"} + write_key "$key" fi ${makeRoomForLink targetPath} # .populate/derived/<name>/result roots the store path. @@ -530,10 +542,13 @@ let # a hard link to the lock file, e.g. in a backup, or what it is a # symlink to. So the lock file of the flake in the directory $1 # gets replaced by a copy first. + # The copy goes to a new file, so nothing that's there already + # gets written through. own_lock() { if test -e "$1"/flake.lock; then - cp -p "$1"/flake.lock "$1"/flake.lock.populate - mv -f "$1"/flake.lock.populate "$1"/flake.lock + own_lock_copy=$(mktemp "$1"/.flake.lock.XXXXXX) + cp -p "$1"/flake.lock "$own_lock_copy" + mv -f "$own_lock_copy" "$1"/flake.lock fi } @@ -1259,8 +1274,22 @@ let rsync' = target: config: sourcePath: /* sh */ '' # rsync writes through a symlink at the target path, e.g. one a symlink or - # flake source left there, into what it points to. - ${runShell target (removeLink target.path)} + # flake source left there, into what it points to. And rsync fixes the + # mode and time of a file it takes for unchanged in place, which changes + # every hard link to it, e.g. one elsewhere, or a backup's. So each file + # with other hard links gets replaced by a copy of its own first. + ${runShell target /* sh */ '' + ${removeLink target.path} + if test -d ${quote target.path}; then + find ${quote target.path} -type f -links +1 -exec sh -c ' + for file; do + copy=$(mktemp "$file.XXXXXX") + cp -p "$file" "$copy" + mv -f "$copy" "$file" + done + ' sh {} + + fi + ''} source_path=${sourcePath} if test -d "$source_path"; then source_path=$source_path/ |