lib/libfs.sh

   1 #!/bin/sh -e
   2 # ==============================================================================
   3 # portsreinstall library script
   4 # - File system operations -
   5 # Copyright (C) 2018 Mamoru Sakaue, MwGhennndo, All Rights Reserved.
   6 # This software is distributed under the 2-Clause BSD License.
   7 # ==============================================================================
   8
   9 # ============= Get the global path of a possibly not yet created file/directory =============
  10 fs_global_path ()
  11 {
  12         local $path_src
  13         path_src=$1
  14         if [ -e "$path_src" ]
  15         then
  16                 realpath "$path_src"
  17         else
  18                 expr "$path_src" : '^/' > /dev/null || echo -n `realpath .`
  19                 echo "$path_src"
  20         fi
  21 }
  22
  23 # ============= Inspect the privilege of the current environment on file system operation =============
  24 fs_inspect_fs_privilege ()
  25 {
  26         local tgv mp mp_regexp mount_privilege basedir
  27         [ -d "${TMPDIR}"/fs_privilege ] && return
  28         tgv=${TMPDIR}/fs_privilege/test_tg
  29         mkdir -p "$tgv" "${TMPDIR}"/fs_privilege/test_mp
  30         mp=`realpath "${TMPDIR}"/fs_privilege/test_mp`
  31         mp_regexp=`str_escape_regexp "$mp"`
  32         echo yes > ${TMPDIR}/fs_privilege/fs_privilege
  33         cat > ${TMPDIR}/fs_privilege/fslist << eof
  34 devfs   devfs
  35 fdescfs null
  36 procfs  proc
  37 tmpfs   tmpfs
  38 nullfs  "$tgv"
  39 unionfs "$tgv"
  40 eof
  41         while read fs tg
  42         do
  43                 if mount -t $fs "$tgv" "$mp" 2> /dev/null && umount "$mp"
  44                 then
  45                         echo yes
  46                 else
  47                         echo no
  48                         echo no > ${TMPDIR}/fs_privilege/fs_privilege
  49                 fi > ${TMPDIR}/fs_privilege/fs_privilege:$fs 2> /dev/null
  50                 umount -f "$mp" 2> /dev/null || :
  51                 [ -e "${TMPDIR}"/fs_privilege/basedir ] && continue
  52                 mount -t $fs "$tgv" "$mp" 2> /dev/null && \
  53                         df "$mp" > ${TMPDIR}/fs_privilege/df:$fs && \
  54                         umount "$mp"
  55                 real_mp=`sed 1d "${TMPDIR}"/fs_privilege/df:$fs | tail -n 1 | \
  56                         sed -E 's/^.*[[:space:]][0-9]+%[[:space:]]+//'`
  57                 echo "$real_mp" | sed -E "s/$mp_regexp$//" > ${TMPDIR}/fs_privilege/basedir
  58         done < ${TMPDIR}/fs_privilege/fslist
  59         mount_privilege=`cat "${TMPDIR}"/fs_privilege/fs_privilege`
  60         if [ "x$mount_privilege" = xyes ]
  61         then
  62                 mount -t nullfs /bin "$mp" 2> /dev/null
  63                 if [ `ls "$mp" 2> /dev/null | wc -l` -gt 0 ]
  64                 then
  65                         echo yes
  66                 else
  67                         echo no
  68                 fi > ${TMPDIR}/fs_privilege/nullfs_target_recognition
  69                 umount -f "$mp" 2> /dev/null || :
  70                 nullfs_target_recognition=`cat "${TMPDIR}"/fs_privilege/nullfs_target_recognition`
  71                 if [ "x$nullfs_target_recognition" = xyes ]
  72                 then
  73                         message_echo "INFO: The current environment has the full required privilege of mounting/unmounting file systems."
  74                 else
  75                         message_echo "INFO: The current environment formally has the full required privilege of mounting/unmounting file systems but the recognition of nullfs/unionfs targets is incorrect."
  76                 fi
  77         else
  78                 echo no > ${TMPDIR}/fs_privilege/nullfs_target_recognition
  79                 message_echo "INFO: The current environment does not have the privilege of mounting/unmounting for the following file system(s)."
  80                 while read fs tg
  81                 do
  82                          mount_privilege=`cat "${TMPDIR}"/fs_privilege/fs_privilege:$fs`
  83                          [ "x$mount_privilege" = xyes ] || echo '  '$fs
  84                 done < ${TMPDIR}/fs_privilege/fslist | message_cat
  85         fi
  86         basedir=`cat "${TMPDIR}"/fs_privilege/basedir 2> /dev/null || :`
  87         if [ -n "$basedir" ]
  88         then
  89                 message_echo "INFO: The current environment will be a chroot/jail guest whose base directory is \"$basedir\"."
  90         fi
  91         if [ "x$opt_invalidate_mount_privilege" = xyes ]
  92         then
  93                 message_echo "INFO: The privilege of mounting/unmounting in this environment is forcibly invalidated."
  94         fi
  95 }
  96
  97 # ============= Check whether mounting file systems are available at the current environment =============
  98 fs_chk_mount_privilege ()
  99 {
 100         local mount_privilege
 101         fs_inspect_fs_privilege
 102         [ "x$opt_invalidate_mount_privilege" = xno ] || return
 103         mount_privilege=`cat "${TMPDIR}"/fs_privilege/fs_privilege`
 104         nullfs_target_recognition=`cat "${TMPDIR}"/fs_privilege/nullfs_target_recognition`
 105         [ "x$nullfs_target_recognition" = xyes -a "x$mount_privilege" = xyes ]
 106 }
 107
 108 # ============= Check whether mounting file systems are available at the current environment =============
 109 fs_chk_unmount_privilege ()
 110 {
 111         local mount_privilege
 112         fs_inspect_fs_privilege
 113         [ "x$opt_invalidate_mount_privilege" = xno ] || return
 114         mount_privilege=`cat "${TMPDIR}"/fs_privilege/fs_privilege`
 115         [ "x$mount_privilege" = xyes ]
 116 }
 117
 118 # ============= Get the base directory the current environment (applicable in case of a chroot guest) =============
 119 fs_get_system_basedir ()
 120 {
 121         fs_inspect_fs_privilege
 122         cat "${TMPDIR}"/fs_privilege/basedir 2> /dev/null || :
 123 }
 124
 125 # ============= Get the regular expression pattern of the actual mount point =============
 126 fs_get_actual_mount_point_pattern ()
 127 {
 128         local mountpoint basedir mountpoint_real
 129         mountpoint=$1
 130         fs_inspect_fs_privilege
 131         basedir=`cat "${TMPDIR}"/fs_privilege/basedir 2> /dev/null || :`
 132         if [ -e  "$mountpoint" ]
 133         then
 134                 mountpoint_real=`realpath "$mountpoint"`
 135         else
 136                 curdir=$mountpoint
 137                 curnode=$mountpoint
 138                 relative=
 139                 while { curbase=`basename "$curdir"`; curdir=`dirname "$curdir"`; [ -n "$curdir" ]; }
 140                 do
 141                         relative=$curbase/$relative
 142                         if [ -e  "$curdir" ]
 143                         then
 144                                 mountpoint_real=`realpath "$curdir"`/$relative
 145                                 break
 146                         fi
 147                 done
 148         fi
 149         mountpoint_real_full=`str_regularize_df_path "$basedir/$mountpoint_real"`
 150         str_escape_regexp "$mountpoint_real_full"
 151 }
 152
 153 # ============= Get mount info at the descendant directory levels required for builder chroot environment =============
 154 fs_get_descendant_mount_info ()
 155 {
 156         local mountpoint mountpoint_real_regexp basedir
 157         mountpoint=$1
 158         mountpoint_real_regexp=`fs_get_actual_mount_point_pattern "$mountpoint"` || return
 159         basedir=`cat "${TMPDIR}"/fs_privilege/basedir 2> /dev/null || :`
 160         basedir_ptn=`str_escape_regexp "$basedir"`
 161         df | sed 1d | grep -E "%[[:space:]]+$mountpoint_real_regexp\/" | while read fs data
 162         do
 163                 echo "$fs" | grep -q -e '^/' -e '^<above>:' && fs=normal
 164                 mp_abs=`echo "$data" | sed -E  's|.*%[[:space:]]+(/.+)$|\1|'`
 165                 mp=`echo "$mp_abs" | sed -E "s|^$basedir_ptn||"`
 166                 relative=`echo "$mp_abs" | sed -E "s|^$mountpoint_real_regexp||"`
 167                 printf '%s\t%s\t%s\n' "$fs" "$mp" "$relative"
 168         done
 169 }
 170
 171 # ============= Repair the unionfs image if applicable and hidden =============
 172 # Use the side effect of find(1) as a medicine for disappearance of lower layer images of unionfs.
 173 # This treatment, however, can lose its effect when the symptom gets serious.
 174 # When the effect is lost, "umount -A" after "shutdown now" may be the only practical solution.
 175 fs_fix_unionfs_image_if_hidden ()
 176 {
 177         local needlepath needlepath_cur needlepath_next needlepath_lowest_exist
 178         needlepath=$1
 179         needlepath_cur=$needlepath
 180         needlepath_lowest_exist=
 181         while :
 182         do
 183                 [ -z "$needlepath_lowest_exist" -a -e "$needlepath_cur" ] && needlepath_lowest_exist=$needlepath_cur
 184                 find -dx "$needlepath_cur" -maxdepth 0 > /dev/null 2>&1 || :
 185                 needlepath_next=`dirname "$needlepath_cur"`
 186                 [ "x$needlepath_cur" = "x$needlepath_next" ] && break
 187                 needlepath_cur=$needlepath_next
 188         done
 189         [ -e "$needlepath" ] && return
 190         if [ -n "$needlepath_lowest_exist" ] && df "$needlepath_lowest_exist" | sed 1d | grep -q '^<above>:'
 191         then
 192                 message_echo "ERROR: Failed to recover a lost mandatory file, probably due to the bug of unionfs: $needlepath" >&2
 193                 mkdir -p "${DBDIR}/execflag"
 194                 touch "${DBDIR}/execflag/unionfs_error"
 195         else
 196                 message_echo "ERROR: Failed to recover a lost mandatory file due to unknown reasons: $needlepath" >&2
 197         fi
 198         exit 1
 199 }
 200
 201 # ============= Check whether a directory is mounted properly =============
 202 fs_chk_mounted ()
 203 {
 204         local type target mountpoint target_ptn mountpoint_real_regexp tmpsrc
 205         type=$1
 206         target=`str_regularize_df_path "$2"`
 207         mountpoint=`str_regularize_df_path "$3"`
 208         target_ptn=`str_escape_regexp "$target"`
 209         mountpoint_real_regexp=`fs_get_actual_mount_point_pattern "$mountpoint"` || return
 210         basedir=`cat "${TMPDIR}"/fs_privilege/basedir 2> /dev/null || :`
 211         basedir_target_ptn=`str_regularize_df_path "$basedir/$target" | str_escape_regexp_filter`
 212         tmpsrc=`df | sed 1d | grep -E "%[[:space:]]+$mountpoint_real_regexp$"`
 213         case $type in
 214                 nullfs )
 215                         echo "$tmpsrc" | grep -qE "^${target_ptn}[[:space:]]" && return
 216                         echo "$tmpsrc" | grep -qE "^${basedir_target_ptn}[[:space:]]" && return
 217                         ;;
 218                 unionfs )
 219                         echo "$tmpsrc" | grep -qE "^<above>:${target_ptn}[[:space:]]" && return
 220                         echo "$tmpsrc" | grep -qE "^<above>:${basedir_target_ptn}[[:space:]]" && return
 221                         ;;
 222                 devfs | fdescfs | procfs | linprocfs | tmpfs )
 223                         echo "$tmpsrc" | grep -q "^$type" && return
 224                         ;;
 225                 *)
 226                         message_echo "ERROR: Unsupported fyle system [$type]" >&2
 227                         exit 1
 228                         ;;
 229         esac
 230         return 1
 231 }
 232