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bash/dup-live-disk.sh

@@ -2,14 +2,14 @@
 #
 # dup-live-disk.sh - duplicate (possibly live) system partitions
 #
-# (C) Bruno Raoult ("br"), 2007-2021
-# Licensed under the Mozilla Public License (MPL) version 2.0.
+# (C) Bruno Raoult ("br"), 2007-2022
+# Licensed under the GNU General Public License v3.0 or later.
 # Some rights reserved. See COPYING.
 #
-# You should have received a copy of the Mozilla Public License along with this
-# program.  If not, see <https://www.mozilla.org/en-US/MPL>
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
 #
-# SPDX-License-Identifier: MPL-2.0 <https://spdx.org/licenses/MPL-2.0.html>
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
 #
 #%MAN_BEGIN%
 # NAME
@@ -37,16 +37,27 @@
 #
 #       -c, --copy=ACTION
 #          ACTION can be 'yes' (all eligible partitions will be copied), 'no'
-#          (no partition will be copied), or 'ask' (will ask for all eligible
-#          partitions). Default is 'no'.
+#          (no partition will be copied), or 'ask'. Default is 'Ask'.
+#          See ACTIONS below.
 #
 #       -d, --dry-run
-#          Dry-run: nothing will be really be done.
+#          Dry-run: nothing will be really be written to disk. This option
+#          0verrides any of '--yes', '--copy', '--fstab', '--grub', and
+#          '--mariadb' options.
 #
-#       -g, --grub
-#          Install grub on destination disk.
-#          Warning: Only works if root partition contains all necessary for
-#          grub: /boot, /usr, etc...
+#       -f, --fstab=ACTION
+#          ACTION ('yes', 'no', or 'ask') defines whether fstab should be
+#          adjusted on destination root partition. Default is 'ask'.
+#          /etc/fstab/LABEL must exist on source root partition. LABEL is the
+#          partition LABEL of destination root disk.
+#          See ACTIONS below.
+#
+#       -g, --grub=ACTION
+#          ACTION ('yes', 'no', 'ask') defines if grub should be installed on
+#          destination disk). Default is 'ask'.
+#          Warning: Only works if root partition contains all necessary files
+#          for grub: /boot, /usr, etc...
+#          See ACTIONS below.
 #
 #       -h, --help
 #          Display short help and exit.
@@ -54,20 +65,75 @@
 #       -m, --man
 #          Display a "man-like" description and exit.
 #
-#       --mariadb
-#          Stop mysql/mariadb before effective copies, restart after.
+#       -M, --mariadb=ACTION
+#          ACTION may be 'yes', 'no', or 'ask', which indicates whether mysql
+#          or mariadb should be stopped before effective partition copies, and
+#          restarted after.
+#          See ACTIONS below.
+#
+#       -n, --no
+#          Will answer 'no' to any question asked to user.
 #
 #       -r, --root=PARTNUM
 #          Mandatory if SRC is provided, forbidden otherwise.
 #          PARTNUM is root partition number on SRC disk.
 #
+#       -y, --yes
+#          Will answer 'yes' to any question asked to user.
+#
+# ACTIONS
+#       Before writing anything, of if something unexpected happens, the
+#       program may ask to proceed. User may answer 'yes', 'no', or 'quit'.
+#       Options --yes, and --no will default respectively to 'yes' and 'no',
+#       default is to ask.
+#       Options '--copy', '--fstab', and '--grub' (which can take the values
+#       'yes', 'no', and 'ask') can override the specific action for copying
+#       partitions, adjusting destination fstab file, and
+#       installing grub on destination disk.
+#
 # EXAMPLES
-#       Copy sda to sdb, root partition is partition (sda1/sdb1)
+#       Copy sda to sdb, root partition is partition 1 (sda1/sdb1) on both
+#       disks. The user will be asked for any action (partition copy, grub,
+#       etc...)
 #       $ sudo dup-live-disk.sh --root 1 sda sdb
 #
-#       Copy live system (where / is mounted) to sdb
+#       Copy live disk (all partitions of current / partition disk) to sdb.
+#       The user will be asked for any action (partition copy, grub, etc...)
 #       $ sudo dup-live-disk.sh sdb
 #
+#       Copy live disk (all partitions of current / partition disk) to sdb.
+#       All valid partitions will be copied, and grub installed on sdb.
+#       $ sudo dup-live-disk.sh --yes sdb
+#
+#       Do not copy partitions, only install grub on sdb.
+#       $ sudo ./dup-live-disk.sh --copy=no --grub=yes sdb
+#       or
+#       $ sudo ./dup-live-disk.sh --no --grub=yes sdb
+#
+# AUTOFS
+#       This script relies on autofs to mount partitions according to partitions
+#       LABELS. See autofs(5) and auto.master(5) for more details.
+#       For example, the following will mount partitions withs LABELS 'root1',
+#       'root2' in /mnt/hd/root1 and /mnt/hd/root2, simply when we try to access
+#       the directories (for example with 'ls /mnt/hd/root1') :
+#
+#       # in file /etc/auto.master
+#       /mnt/hd   /etc/auto.hd              --timeout 60 --ghost
+#
+#       # in file /etc/auto.hd
+#       *         -fstype=auto,defaults     :LABEL=&
+#
+#       This script uses /mnt as default autofs directory. In fact, /mnt contains
+#       symbolic links to different disk labels :
+#
+#       $ ls -l /mnt/root?
+#       lrwxrwxrwx 1 root root 8 Oct 10  2020 /mnt/root1 -> hd/root1/
+#       lrwxrwxrwx 1 root root 8 May 25  2018 /mnt/root2 -> hd/root2/
+#
+#       It means that accessing /mnt/root1 will automagically mount /mnt/hd/root1.
+#       With the maps above, and without the /mnt symlinks, it is possible to
+#       use '--autofs=/mnt/hd' to directly use the automounter map.
+#
 # BUGS
 #       * Cannot generate grub with a separate /boot partition.
 #       * This script will not work for all situations, I strongly suggest you
@@ -75,7 +141,6 @@
 #       * Extended attributes are not preserved (easy fix, but I cannot test)
 #
 # TODO
-#       * Write about autofs configuration.
 #       * Log levels
 #%MAN_END%
 
@@ -88,7 +153,7 @@ CMD="${0##*/}"
 VALIDFS=(ext3 ext4 btrfs vfat reiserfs xfs zfs)
 
 function man {
-    sed -n '/^#%MAN_BEGIN%/,/^#%MAN_END%$/{//!s/^#[ ]\{0,1\}//p}' "$SCRIPT"
+    sed -n '/^#%MAN_BEGIN%/,/^#%MAN_END%$/{//!s/^#[ ]\{0,1\}//p}' "$SCRIPT" | more
 }
 
 function usage {
@@ -98,40 +163,27 @@ Duplicate SRC (or live system) disk partitions to DST disk partitions.
 
 Options:
       -a, --autofs=DIR     autofs "LABEL-based" directory. Default is '/mnt'.
-      -c, --copy=ACTION    do partitions copies ('yes'), do not copy then ('no')
-                           or ask for each of them ('ask'). Default is 'no'.
+      -c, --copy=ACTION    do partitions copies (ACTION='yes', 'no, 'ask).
+                           Default is 'ask'
       -d, --dry-run        dry-run: nothing will be written to disk
-      -g, --grub           install grub on destination disk
+      -f, --fstab=ACTION   adjust fstab on destination disk ('yes', 'no, 'ask')
+                           Default is 'ask'
+      -g, --grub=ACTION    install grub on destination disk ('yes', 'no, 'ask')
+                           Default is 'ask'
       -h, --help           this help
       -m, --man            display a "man-like" page and exit
-      --mariadb            stop and restart mysql/mariadb server before and
-                           after copies
+      -M, --mariadb=ACTION stop and restart mysql/mariadb server before and
+                           after copies ('yes', 'no', 'ask').
+                           Default is 'ask'
+      -n, --no             Will answer 'no' to any question
       -r, --root=PARTNUM   root partition number on SRC device
                            mandatory if and only if SRC is provided
+      -y, --yes            Will answer 'yes' to any question
 
 SRC and DST have strong constraints on partitions schemes and naming.
 Type '$CMD --man" for more details"
 _EOF
-    exit 0
-}
-
-# mariadb start/stop
-function mariadb_maybe_stop {
-    if [[ $MARIADB == yes ]] && systemctl is-active --quiet mysql; then
-        #log -n "stopping mariadb/mysql... "
-        echorun systemctl stop mariadb
-        # bug if script stops here
-        MARIADBSTOPPED=yes
-        #log "done."
-    fi
-}
-function mariadb_maybe_start {
-    if [[ $MARIADB == yes && $MARIADBSTOPPED == yes ]]; then
-        #log -n "restarting mariadb/mysql... "
-        echorun systemctl start mariadb
-        MARIADBSTOPPED=no
-        #log "done."
-    fi
+    return 0
 }
 
 # log function
@@ -159,16 +211,73 @@ function log {
     return 0
 }
 
-# prints out and run a command.
-function echorun {
+# prints out and run (maybe) a command.
+function echorun_maybe {
     if [[ "$DRYRUN" == 'yes' ]]; then
-        log "%s " "dry-run: " "$@"
+        log "dry-run: %s" "$*"
     else
-        log "%s " "$@"
+        log "%s" "$*"
         "$@"
     fi
 }
 
+yesno() {
+    local reason answer
+
+    # shellcheck disable=SC2059
+    printf -v reason "*** $1 [y/n/q] ? " "${@:2}"
+
+    while true; do
+        if [[ $YESNO =~ ^(yes|no)$ ]]; then
+            answer="$YESNO"
+            # shellcheck disable=SC2059
+            printf "$reason%s\n" "$answer"
+        else
+            read -p "$reason" -r answer
+        fi
+        case "${answer,,}" in
+            y|yes) return 0
+                   ;;
+            n|no) return 1
+                  ;;
+            q|quit) printf "Aborting...\n"
+                    exit 1
+        esac
+    done
+}
+
+# mariadb start/stop
+function mariadb_maybe_stop {
+    [[ $MARIADBSTOPPED == yes ]] && return 0
+    if systemctl is-active --quiet mysql; then
+        if [[ $MARIADB == ask ]]; then
+            if yesno "Stop MariaDB/MySQL"; then
+               MARIADB=yes
+            else
+               MARIADB=no
+            fi
+        fi
+        if [[ $MARIADB == no ]]; then
+            log "Warning: MariaDB/MySQL is running, database corruption possible on DEST disk."
+            return 0
+        fi
+        echorun_maybe systemctl stop mariadb
+        # bug if script stops here
+        MARIADBSTOPPED=yes
+    else
+        log "MariaDB/MySQL is inactive."
+    fi
+}
+
+function mariadb_maybe_start {
+    if [[ $MARIADB == yes && $MARIADBSTOPPED == yes ]]; then
+        #log -n "restarting mariadb/mysql... "
+        echorun_maybe systemctl start mariadb
+        MARIADBSTOPPED=no
+        #log "done."
+    fi
+}
+
 function error_handler {
     local ERROR=$2
     log "FATAL: Error line $1, exit code $2. Aborting."
@@ -184,12 +293,14 @@ function exit_handler {
     if [[ -n "$DSTMNT" ]] && mountpoint -q "$DSTMNT"; then
         for mnt in "$DSTMNT"/{dev,proc,sys}; do
             if mountpoint -q "$mnt"; then
-                echorun umount "$mnt"
+                # https://unix.stackexchange.com/questions/693346
+                if ! echorun_maybe umount "$mnt"; then
+                    echorun_maybe umount --lazy "$mnt"
+                fi
             fi
         done
     fi
 }
-
 trap 'exit_handler $LINENO' EXIT
 
 function check_block_device {
@@ -212,23 +323,33 @@ function check_block_device {
     return 0
 }
 
-# check that /etc/fstab.XXX exists in SRCR
+# check that /etc/fstab.DESTLABEL exists in SRC disk.
 function check_fstab {
-    local fstab
-    for f in "$SRCROOTLABEL" "$DSTROOTLABEL"; do
-        fstab="${AUTOFS_DIR}/$SRCROOTLABEL/etc/fstab.$f"
-        #log -n "======= check %s=%s " "$fstab" "$f"
-        if [[ ! -f "$fstab" ]]; then
-            log "Fatal: source or destination fstab (%s) not found" "$fstab"
-            return 1
-        fi
-    done
+    local etc="${AUTOFS_DIR}/$SRCROOTLABEL/etc"
+    local fstab="fstab.$DSTROOTLABEL"
+    #if [[ "$FSTAB" != no ]]; then
+    if [[ ! -f "$etc/$fstab" ]]; then
+        FSTAB=no
+        log "Warning: No target fstab (%s) on SRC disk" "$etc/$fstab"
+    else
+        log "Info: Found target fstab (%s) in SRC root partition (%s)." "$fstab" "$etc"
+    fi
     return 0
 }
 
 function fix_fstab {
     local fstab="${AUTOFS_DIR}/$DSTROOTLABEL/etc/fstab"
-    echorun ln -f "$fstab.$DSTROOTLABEL" "$fstab"
+
+    #[[ ! -f "$fstab" ]] && log "Warning: DST fstab will be wrong !" && FSTAB=no
+    if [[ "$FSTAB" == ask ]]; then
+        yesno "Link %s to %s" "$fstab.$DSTROOTLABEL" "$fstab" && FSTAB=yes || FSTAB=no
+    fi
+    if [[ "$FSTAB" == no ]]; then
+        log "Warning: DST fstab will be *wrong*, boot is compromised"
+    else
+        echorun_maybe ln -f "$fstab.$DSTROOTLABEL" "$fstab"
+    fi
+    return 0
 }
 
 # check if $1 is in array $2 ($2 is by reference)
@@ -241,29 +362,6 @@ function in_array {
     return 1
 }
 
-# get y/n/q user input
-function yesno {
-    local input
-    while true; do
-        printf "%s " "$1"
-        read -r input
-        case "$input" in
-            y|Y)
-                return 0
-                ;;
-            q|Q)
-                log "aborting..."
-                exit 0
-                ;;
-            n|N)
-                return 1
-                ;;
-            *)
-                printf "invalid answer. "
-        esac
-    done
-}
-
 # source and destination devices, root partition
 SRC=""
 DST=""
@@ -272,14 +370,17 @@ ROOTPARTNUM=""
 AUTOFS_DIR=/mnt
 
 DRYRUN=no                                         # dry-run
-GRUB=no                                           # install grub
-COPY=no                                           # do FS copies
-MARIADB=no                                        # stop/start mysql/mariadb
+FSTAB=ask                                         # adjust fstab
+GRUB=ask                                          # install grub
+COPY=ask                                          # do FS copies
+MARIADB=ask                                       # stop/start mysql/mariadb
 MARIADBSTOPPED=no                                 # mysql stopped ?
+YESNO=                                            # default answer
+ROOTCOPIED=no                                     # was root partition copied ?
 
 # short and long options
-SOPTS="a:c:dghmr:"
-LOPTS="autofs:,copy:,dry-run,grub,help,man,mariadb,root:"
+SOPTS="a:c:df:g:hmM:nr:y"
+LOPTS="autofs:,copy:,dry-run,fstab:,grub:,help,man,mariadb:,no,root:,yes"
 
 if ! TMP=$(getopt -o "$SOPTS" -l "$LOPTS" -n "$CMD" -- "$@"); then
     log "Use '$CMD --help' or '$CMD --man' for help."
@@ -296,7 +397,7 @@ while true; do
             shift
             ;;
         '-c'|'--copy')
-            case "$2" in
+            case "${2,,}" in
                 "no") COPY=no;;
                 "yes") COPY=yes;;
                 "ask") COPY=ask;;
@@ -309,8 +410,27 @@ while true; do
         '-d'|'--dry-run')
             DRYRUN=yes
             ;;
+        '-f'|'--fstab')
+            case "${2,,}" in
+                "no") FSTAB=no;;
+                "yes") FSTAB=yes;;
+                "ask") FSTAB=ask;;
+                *) log "invalid '$2' --fstab flag"
+                   usage
+                   exit 1
+            esac
+            shift
+            ;;
         '-g'|'--grub')
-            GRUB=yes
+            case "${2,,}" in
+                "no") GRUB=no;;
+                "yes") GRUB=yes;;
+                "ask") GRUB=ask;;
+                *) log "invalid '$2' --grub flag"
+                   usage
+                   exit 1
+            esac
+            shift
             ;;
         '-h'|'--help')
             usage
@@ -320,8 +440,19 @@ while true; do
             man
             exit 0
             ;;
-        '--mariadb')
-            MARIADB=yes
+        '-n'|'--no')
+            YESNO=no
+            ;;
+        '-M'|'--mariadb')
+            case "${2,,}" in
+                "no") MARIADB=no;;
+                "yes") MARIADB=yes;;
+                "ask") MARIADB=ask;;
+                *) log "invalid '$2' --mariadb flag"
+                   usage
+                   exit 1
+            esac
+            shift
             ;;
         '-r'|'--root')
             ROOTPARTNUM="$2"
@@ -335,6 +466,9 @@ while true; do
             shift
             break
             ;;
+        '-y'|'--yes')
+            YESNO=yes
+            ;;
         *)
             usage
             log 'Internal error!'
@@ -344,6 +478,12 @@ while true; do
     shift
 done
 
+# check if current user is root
+if (( EUID != 0 )); then
+    log "This script must be run as root... Aborting."
+    exit 1
+fi
+
 case "$#" in
     1)
         if [[ -n "$ROOTPARTNUM" ]]; then
@@ -367,6 +507,11 @@ case "$#" in
         SRCROOT="$SRC$ROOTPARTNUM"
         DST="/dev/$2"
         ;;
+    0)
+        log "Missing destination disk."
+        usage
+        exit 1
+        ;;
     *)
         usage
         exit 1
@@ -374,7 +519,7 @@ esac
 
 # check SRC and DST are different, find out their characteristics
 if [[ "$SRC" = "$DST" ]]; then
-    log "%s: Fatal: destination disk (%s) cannot be source.\n" "$CMD" "$SRC"
+    log "Fatal: destination and source disk are identical (%s)" "$SRC"
     log "Use '%s --help' or '%s --man' for help." "$CMD" "$CMD"
     exit 1
 fi
@@ -383,7 +528,6 @@ check_block_device "destination disk" w "$DST"
 check_block_device "source root partition" r "$SRCROOT"
 
 SRCROOTLABEL=$(lsblk -no label "$SRCROOT")
-SRCCHAR=${SRCROOTLABEL: -1}
 ROOTLABEL=${SRCROOTLABEL:0:-1}
 
 # find out all partitions labels on SRC disk...
@@ -394,9 +538,9 @@ declare -a LABELS=(${SRCLABELS[@]%?})
 
 # ... and corresponding partition device and fstype
 declare -a SRCDEVS SRCFS SRC_VALID_FS
-for ((i=0; i<${#LABELS[@]}; ++i)); do
-    TMP="${LABELS[$i]}$SRCCHAR"
+for ((i=0; i<${#SRCLABELS[@]}; ++i)); do
     TMP="${SRCLABELS[$i]}"
+    #log "TMP=%s" "$TMP"
     TMPDEV=$(findfs LABEL="$TMP")
     TMPFS=$(lsblk -no fstype "$TMPDEV")
     log "found LABEL=$TMP DEV=$TMPDEV FSTYPE=$TMPFS"
@@ -422,13 +566,13 @@ declare -a DSTLABELS DSTDEVS DSTFS DST_VALID_FS
 # Do the same for corresponding DST partitions labels, device, and fstype
 for ((i=0; i<${#LABELS[@]}; ++i)); do
     TMP="${LABELS[$i]}$DSTCHAR"
-    log -n "Looking for [%s] label... " "$TMP"
+    log -n "Looking for [%s] label : " "$TMP"
     if ! TMPDEV=$(findfs LABEL="$TMP"); then
         log "not found."
         exit 1
     fi
     TMPDISK=${TMPDEV%?}
-    log -n "DEV=%s... DISK=%s..." "$TMPDEV" "$TMPDISK"
+    log -n "DEV=%s DISK=%s " "$TMPDEV" "$TMPDISK"
     if [[ "$TMPDISK" != "$DST" ]]; then
         log "wrong disk (%s != %s)" "$TMPDISK" "$DST"
         exit 1
@@ -469,30 +613,44 @@ for ((i=0; i<${#LABELS[@]}; ++i)); do
     #log "\t%s %s %s %s %s" rsync "${RSYNCOPTS}" "$FILTER" "$SRCPART" "$DSTPART"
     copy="$COPY"
     if [[ "$COPY" == 'ask' ]]; then
-        yesno "Copy $SRCPART to $DSTPART ? [y/n/q]" && copy=yes || copy=no
+        yesno "Copy $SRCPART to $DSTPART" && copy=yes || copy=no
     fi
     if [[ "$copy" == yes ]]; then
         mariadb_maybe_stop
         # shellcheck disable=SC2086
-        echorun rsync "$FILTER" ${RSYNCOPTS} "$SRCPART" "$DSTPART"
+        echorun_maybe rsync "$FILTER" ${RSYNCOPTS} "$SRCPART" "$DSTPART"
         if [[ "$DSTROOTLABEL" == "${DSTLABELS[$i]}" ]]; then
+            ROOTCOPIED=yes
             fix_fstab
         fi
     fi
     #log ""
 done
+mariadb_maybe_start
 
 # grub install
-if [[ "$GRUB" == yes ]]; then
+if [[ $GRUB == ask ]]; then
+    if ! yesno "install grub on %s (root: %s)" "$GRUB_DEV" "$GRUB_ROOT"; then
+        GRUB=no
+    fi
+fi
+if [[ $GRUB == no ]]; then
+    if [[ $ROOTCOPIED == yes ]]; then
+        log "Warning: root filesystem changed, and skipping grub install on %s, boot will probably fail." "$DST"
+    else
+        log "Warning: Skipping grub install on %s." "$DST"
+    fi
+else
     log "installing grub on $DST..."
+
     DSTMNT="$AUTOFS_DIR/$DSTROOTLABEL"
     # mount virtual devices
-    echorun mount -o bind /sys  "$DSTMNT/sys"
-    echorun mount -o bind /proc "$DSTMNT/proc"
-    echorun mount -o bind /dev  "$DSTMNT/dev"
+    echorun_maybe mount -o bind /sys  "$DSTMNT/sys"
+    echorun_maybe mount -o bind /proc "$DSTMNT/proc"
+    echorun_maybe mount -o bind /dev  "$DSTMNT/dev"
 
-    echorun chroot "$DSTMNT" update-grub
-    echorun chroot "$DSTMNT" grub-install "$DST"
+    echorun_maybe chroot "$DSTMNT" update-grub
+    echorun_maybe chroot "$DSTMNT" grub-install "$DST"
 fi
 
 exit 0

bash/sync-conf-example.sh

@@ -2,14 +2,14 @@
 #
 # sync-conf-example.sh - a "sync.sh" configuration file example.
 #
-# (C) Bruno Raoult ("br"), 2007-2021
-# Licensed under the Mozilla Public License (MPL) version 2.0.
+# (C) Bruno Raoult ("br"), 2007-2022
+# Licensed under the GNU General Public License v3.0 or later.
 # Some rights reserved. See COPYING.
 #
-# You should have received a copy of the Mozilla Public License along with this
-# program.  If not, see <https://www.mozilla.org/en-US/MPL>
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
 #
-# SPDX-License-Identifier: MPL-2.0 <https://spdx.org/licenses/MPL-2.0.html>
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
 #
 # USAGE:
 #    sync.sh -rfu /path/to/sync-conf-example.sh

bash/sync.sh

@@ -2,14 +2,14 @@
 #
 # sync.sh - a backup utility using ssh/rsync facilities.
 #
-# (C) Bruno Raoult ("br"), 2007-2021
-# Licensed under the Mozilla Public License (MPL) version 2.0.
+# (C) Bruno Raoult ("br"), 2007-2022
+# Licensed under the GNU General Public License v3.0 or later.
 # Some rights reserved. See COPYING.
 #
-# You should have received a copy of the Mozilla Public License along with this
-# program.  If not, see <https://www.mozilla.org/en-US/MPL>
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
 #
-# SPDX-License-Identifier: MPL-2.0 <https://spdx.org/licenses/MPL-2.0.html>
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
 #
 # NAME
 #       sync.sh - a backup utility using ssh/rsync facilities.
@@ -152,9 +152,10 @@ LOCKED=n                        # indicates if we created lock file.
 SUBJECT="${0##*/} ${*##*/}"     # mail subject (removes paths)
 ERROR=0                         # set by error_handler when called
 STARTTIME=$(date +%s)           # time since epoch in seconds
+CMDNAME=${0##*/}
 
 usage () {
-    echo "usage: ${0##*/} [-ymwdnfrzuD]" config-file
+    printf "usage: %s [-ymwdnfrzuD] config-file\n" "$CMDNAME"
     exit 1
 }
 
@@ -185,6 +186,7 @@ if [[ ! -f "$CONFIG" ]]; then
     echo "No $CONFIG file."
     usage
 fi
+# shellcheck source=/dev/null
 source "$CONFIG"
 
 # we set backups to be done if none has been set yet (i.e. none is "y").
@@ -261,27 +263,48 @@ exit_handler() {
         exec 0<<<""             # force empty input for the following
     fi
 
+    SECS=$(($(date +%s)-STARTTIME))
+
     # Warning: no logs allowed here (before next braces), as stdout is no
     # more handled the final way.
     {
-        SECS=$(($(date +%s)-STARTTIME))
-
         # we write these logs here so that they are on top if no DEBUG.
-        log "Exit code: $ERROR"
-        log "$(printf "Elapsed time: $SECS seconds (%d:%02d:%02d)\n\n" \
-            $((SECS/3600)) $((SECS%3600/60)) $((SECS%60)))"
+        printf "%s: Exit code: %d\n\n" "$CMDNAME" "$ERROR"
+        printf "Elapsed time: %d seconds (%d:%02d:%02d)\n\n" \
+            $((SECS)) $((SECS/3600)) $((SECS%3600/60)) $((SECS%60))
 
         if [[ -n $FILTERLNK ]]; then
-            grep -vE "^(hf|cd|cL)[ \+]" ;
+            grep -vE "^(hf|cd|cL)[ \+]"
         else
-            cat ;
+            cat
         fi
     } |
     {
         if [[ -n $MAILTO ]]; then
-            mail -s "${SUBJECT}" "${MAILTO}";
+            MIMESTR="FEDCBA987654321"
+            MIMEHDR="Content-Type: multipart/mixed; boundary=\"$MIMESTR\""
+            {
+                # We write a short information in email's body
+                printf "\n--%s\n" "$MIMESTR"
+                printf 'Content-Type: text/plain; charset=UTF-8\n'
+                printf '\n'
+
+                # send first lines in message body (until the mark line)
+                while read -r line; do
+                    [[ $line =~ ^\*+\ Mark$ ]] && break
+                    printf "%s\n" "$line"
+                done
+
+                printf "\n--%s\n" "$MIMESTR"
+                printf "Content-Type: application/gzip\n"
+                printf "Content-Transfer-Encoding: base64\n"
+                printf 'Content-Disposition: attachment; filename="sync.log.txt.gz"\n'
+                printf '\n'
+                gzip | uuencode -m "dummy" | sed '1d; $d'
+                printf "\n--%s--\n" "$MIMESTR"
+            } | mail -a "$MIMEHDR" -s "${SUBJECT}" "${MAILTO}"
         else
-            cat;
+            cat
         fi
     }
 }
@@ -300,7 +323,10 @@ if [[ ! -d $SOURCEDIR ]]; then
     log -s "Source directory (\"${SOURCEDIR}\") is not a valid directory."
     error_handler $LINENO 1
 fi
-cd ${SOURCEDIR}
+if ! cd ${SOURCEDIR}; then
+    log -s "Cannot cd to \"${SOURCEDIR}\"."
+    error_handler $LINENO 1
+fi
 
 # prepare list of backups, such as "daily 7 weekly 4", etc...
 TODO=()
@@ -310,10 +336,30 @@ TODO=()
 [[ $YEARLY = y && $NYEARS -gt 0 ]]   && TODO+=(yearly "$NYEARS")
 
 log -l -t "Starting backup."
+log "Hostname: $(hostname)"
+log "Operating System: $(uname -sr) on $(uname -m)"
+log "Bash version: ${BASH_VERSINFO[0]}.${BASH_VERSINFO[1]}.${BASH_VERSINFO[2]}"
 log "Config : ${CONFIG}"
 log "Src dir: ${SOURCEDIR}"
 log "Dst dir: ${SERVER}:${DESTDIR}"
-log "Actions: ${TODO[@]}"
+log "Actions: ${TODO[*]}"
+# check for available gzip and uuencode
+declare -a cmdavail=()
+for cmd in gzip uuencode; do
+    log -n "Checking for $cmd... "
+    if type -p "$cmd" > /dev/null; then
+        log "ok"
+    else
+        log "NOK"
+        cmdavail+=("$cmd")
+    fi
+done
+if (( ${#cmdavail[@]} )); then
+    log -s "Fatal. Please install the followine: ${cmdavail[*]}."
+    error_handler $LINENO 1
+fi
+
+log -s "Mark"                   # to separate email body
 
 # select handling depending on local or networked target (ssh or not).
 if [[ $SERVER = local ]]; then  # local backup
@@ -342,6 +388,7 @@ echorun () {
 # we first build a list from $2 to zero, with 2 padded digits: 03 02 01 00
 # then we remove $1-03, and move $1-02 to $1-03, $1-01 to $1-02, etc...
 rotate-files () {
+    # shellcheck disable=SC2207
     files=( $(seq -f "${DESTDIR}/${1}-%02g" "${2}" -1 0) )
     log -s -t -n "${files[0]##*/} deletion... "
     status=0
@@ -364,7 +411,7 @@ rotate-files () {
             [[ $DEBUG = y ]] && log -n "${files[1]:(-2)} "
             ${MOVE} "${files[1]}" "${files[0]}"
         fi
-        unset files[0]          # shift and pack array
+        unset "files[0]"        # shift and pack array
         files=( "${files[@]}" )
     done
     log "done."

bash/trans.sh

@@ -2,14 +2,14 @@
 #
 # trans.sh - Translate words using linguee.com.
 #
-# (C) Bruno Raoult ("br"), 2021
-# Licensed under the Mozilla Public License (MPL) version 2.0.
+# (C) Bruno Raoult ("br"), 2021-2022
+# Licensed under the GNU General Public License v3.0 or later.
 # Some rights reserved. See COPYING.
 #
-# You should have received a copy of the Mozilla Public License along with this
-# program.  If not, see <https://www.mozilla.org/en-US/MPL>
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
 #
-# SPDX-License-Identifier: MPL-2.0 <https://spdx.org/licenses/MPL-2.0.html>
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
 #
 # Options: See usage function in code below.
 

c/COPYING

@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
+
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
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+
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+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
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+
+  "This License" refers to version 3 of the GNU General Public License.
+
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+same work.
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+conditions are met.  This License explicitly affirms your unlimited
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+covered work is covered by this License only if the output, given its
+content, constitutes a covered work.  This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+
+  You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force.  You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
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+for you must do so exclusively on your behalf, under your direction
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+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
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+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
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+  You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
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+keep intact all notices of the absence of any warranty; and give all
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+give under the previous paragraph, plus a right to possession of the
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+the predecessor has it or can get it with reasonable efforts.
+
+  You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License.  For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+
+  11. Patents.
+
+  A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based.  The
+work thus licensed is called the contributor's "contributor version".
+
+  A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version.  For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+
+  Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+
+  In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement).  To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+
+  If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients.  "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+
+  If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

c/bits.h

@@ -0,0 +1,178 @@
+/* bits.h - bits functions.
+ *
+ * Copyright (C) 2021-2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+#ifndef BITS_H
+#define BITS_H
+
+#include <stdint.h>
+
+/* next include will define __WORDSIZE: 32 or 64
+ */
+#include <bits/wordsize.h>
+
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#endif
+
+/* no plan to support 32bits for now...
+ */
+#if __WORDSIZE != 64
+#error "Only 64 bits word size supported."
+#endif
+
+/* fixed-size types
+ */
+typedef int64_t  s64;
+typedef int32_t  s32;
+typedef int16_t  s16;
+typedef int8_t   s8;
+
+typedef uint64_t u64;
+typedef uint32_t u32;
+typedef uint16_t u16;
+typedef uint8_t  u8;
+
+/* convenience types
+ */
+typedef unsigned long int ulong;
+typedef unsigned int uint;
+typedef unsigned short ushort;
+typedef unsigned char uchar;
+
+/* char is a special case, as it can be signed or unsigned
+ */
+typedef signed char schar;
+
+/* count trailing zeroes : 00101000 -> 3
+ *                              ^^^
+ */
+static inline int ctz64(u64 n)
+{
+#   if __has_builtin(__builtin_ctzl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin ctzl.\n");
+#   endif
+    return __builtin_ctzl(n);
+
+#   elif __has_builtin(__builtin_clzl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin clzl.\n");
+#   endif
+    return __WORDSIZE - (__builtin_clzl(n & -n) + 1);
+
+#   else
+#   ifdef DEBUG_BITS
+    log_f(1, "emulated.\n");
+#   endif
+    return popcount64((n & −n) − 1);
+#   endif
+}
+
+/* count leading zeroes : 00101000 -> 2
+ *                        ^^
+ */
+static inline int clz64(u64 n)
+{
+#   if __has_builtin(__builtin_clzl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin.\n");
+#   endif
+    return __builtin_clzl(n);
+
+#   else
+#   ifdef DEBUG_BITS
+    log_f(1, "emulated.\n");
+#   endif
+    u64 r, q;
+
+    r = (n > 0xFFFFFFFF) << 5; n >>= r;
+    q = (n > 0xFFFF)     << 4; n >>= q; r |= q;
+    q = (n > 0xFF  )     << 3; n >>= q; r |= q;
+    q = (n > 0xF   )     << 2; n >>= q; r |= q;
+    q = (n > 0x3   )     << 1; n >>= q; r |= q;
+    r |= (n >> 1);
+    return __WORDSIZE - r - 1;
+#   endif
+}
+
+/* find first set :  00101000 -> 4
+ *                       ^
+ */
+static inline uint ffs64(u64 n)
+{
+#   if __has_builtin(__builtin_ffsl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin ffsl.\n");
+#   endif
+    return __builtin_ffsll(n);
+
+#   elif __has_builtin(__builtin_ctzl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin ctzl.\n");
+#   endif
+    if (n == 0)
+        return (0);
+    return __builtin_ctzl(n) + 1;
+
+#   else
+#   ifdef DEBUG_BITS
+    log_f(1, "emulated.\n");
+#   endif
+    return popcount64(n ^ ~-n);
+#   endif
+}
+
+static inline int popcount64(u64 n)
+{
+#   if __has_builtin(__builtin_popcountl)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin.\n");
+#   endif
+    return __builtin_popcountl(n);
+
+#   else
+#   ifdef DEBUG_BITS
+    log_f(1, "emulated.\n");
+#   endif
+    int count = 0;
+    while (n) {
+        count++;
+        n &= (n - 1);
+    }
+    return count;
+#   endif
+}
+
+/** bit_for_each64 - iterate over an u64 bits
+ * @pos:        an int used as current bit
+ * @tmp:        a temp u64 used as temporary storage
+ * @ul:         the u64 to loop over
+ *
+ * Usage:
+ * u64 u=139, _t;     //  u=b10001011
+ * int cur;
+ * bit_for_each64(cur, _t, u) {
+ *     printf("%d\n", cur);
+ * }
+ * This will display the position of each bit set in ul: 1, 2, 4, 8
+ *
+ * I should probably re-think the implementation...
+ */
+#define bit_for_each64(pos, tmp, ul)                                    \
+    for (tmp = ul, pos = ffs64(tmp); tmp; tmp &= (tmp - 1),  pos = ffs64(tmp))
+
+/** or would it be more useful (counting bits from zero instead of 1) ?
+ */
+#define bit_for_each64_2(pos, tmp, ul)                                  \
+    for (tmp = ul, pos = ctz64(tmp); tmp; tmp ^= 1UL<<pos, pos = ctz64(tmp))
+
+#endif  /* BITS_H */

c/debug.c

@@ -0,0 +1,111 @@
+/* debug.c - debug/log management
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <time.h>
+
+#ifndef DEBUG_DEBUG
+#define DEBUG_DEBUG
+#endif
+
+#include "debug.h"
+
+#define NANOSEC  1000000000                       /* nano sec in sec */
+#define MILLISEC 1000000                          /* milli sec in sec */
+
+static s64 timer_start;                           /* in nanosecond */
+static u32 debug_level=0;
+
+void debug_level_set(u32 level)
+{
+    debug_level = level;
+
+    log(1, "debug level set to %u\n", level);
+}
+
+void debug_init(u32 level)
+{
+    struct timespec timer;
+
+    debug_level_set(level);
+    if (!clock_gettime(CLOCK_MONOTONIC, &timer)) {
+        timer_start = timer.tv_sec * NANOSEC + timer.tv_nsec;
+    }
+    else {
+        timer_start = 0;
+    }
+    log(0, "timer started.\n");
+}
+
+inline static s64 timer_elapsed()
+{
+    struct timespec timer;
+
+    clock_gettime(CLOCK_MONOTONIC, &timer);
+    return (timer.tv_sec * NANOSEC + timer.tv_nsec) - timer_start;
+}
+
+
+/* void debug - log function
+ * @timestamp : boolean
+ * @indent    : indent level (2 spaces each)
+ * @src       : source file/func name (or NULL)
+ * @line      : line number
+ */
+void debug(u32 level, bool timestamp, u32 indent, const char *src,
+           u32 line, const char *fmt, ...)
+{
+    if (level > debug_level)
+        return;
+
+    va_list ap;
+
+    if (indent)
+        printf("%*s", 2*(indent-1), "");
+
+    if (timestamp) {
+        s64 diff = timer_elapsed();
+        printf("%ld.%03ld ", diff/NANOSEC, (diff/1000000)%1000);
+        printf("%010ld ", diff);
+    }
+
+    if (src) {
+        if (line)
+            printf("[%s:%u] ", src, line);
+        else
+            printf("[%s] ", src);
+    }
+    va_start(ap, fmt);
+    vprintf(fmt, ap);
+    va_end(ap);
+}
+
+#ifdef BIN_debug
+#include <unistd.h>
+
+int main()
+{
+    int foo=1;
+    debug_init(5);
+
+    log(0, "log0=%d\n", foo++);
+    log(1, "log1=%d\n", foo++);
+    log(2, "log2=%d\n", foo++);
+    log_i(2, "log_i 2=%d\n", foo++);
+    log_i(5, "log_i 5=%d\n", foo++);
+    log_i(6, "log_i 6=%d\n", foo++);
+    log_it(4, "log_it 4=%d\n", foo++);
+    log_f(1, "log_f 5=%d\n", foo++);
+}
+#endif

c/debug.h

@@ -0,0 +1,86 @@
+/* move.h - debug/log management.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "bits.h"
+
+#define _unused __attribute__((__unused__))
+#define _printf __attribute__ ((format (printf, 6, 7)))
+#ifdef DEBUG_DEBUG
+void debug_init(u32 level);
+void debug_level_set(u32 level);
+void debug_devel_set(u32 level);
+void _printf debug(u32 level, bool timestamp,
+                   u32 indent, const char *src,
+                   u32 line, const char *, ...);
+#else  /* DEBUG_DEBUG */
+static inline void debug_init(_unused u32 level) {}
+static inline void debug_level_set(_unused u32 level) {}
+static inline void debug_devel_set(_unused u32 level) {}
+static inline void _printf debug(_unused u32 level, _unused bool timestamp,
+                                 _unused u32 indent, _unused const char *src,
+                                 _unused u32 line, const char *, ...) {}
+#endif  /* DEBUG_DEBUG */
+#undef _unused
+#undef _printf
+
+/* format: only printf
+ */
+#define log(level, fmt, args...) \
+    debug((level), false, 0, NULL, 0, fmt, ##args)
+
+/* format : indent, no func name, no timestamp
+ * >>>>val=2
+ */
+#define log_i(level, fmt, args...) \
+    debug((level), false, (level), NULL, 0, fmt, ##args)
+
+/* format : func name, no indent, no timestamp
+ * [foo] val=2
+ */
+#define log_f(level, fmt, args...) \
+    debug((level), false, 0, __func__, 0, fmt, ##args)
+
+/* format : func name, no indent, no timestamp
+ * >>>> [foo:15] val=2
+ */
+#define log_if(level, fmt, args...) \
+    debug((level), false, (level), __func__, __LINE__, fmt, ##args)
+
+/* format : func name, indent, timestamp
+ * >>>>foo:15 val=2
+ */
+#define log_it(level, fmt, args...) \
+    debug((level), true, (level), __func__, __LINE__, fmt, ##args)
+
+/* format: file name, no indent, no timestamp
+ * foo:15 val=2
+ *
+ * #define log_f(level, fmt, args...)                            \
+ *   debug((level), false, 0, __FILE__, __LINE__, fmt, args)
+ */
+
+#else
+#define log(level, fmt, args...)
+#define log_i(...)
+#define log_f(...)
+#define log_if(...)
+#define log_it(...)
+#define log_f(...)
+
+#endif  /* DEBUG_H */

c/list.h

@@ -4,11 +4,13 @@
  * Main change is that I don't use READ_ONCE and WRITE_ONCE
  * See https://www.kernel.org/doc/Documentation/memory-barriers.txt
  */
+
 #ifndef __BR_LIST_H
 #define __BR_LIST_H
 
 #include <stddef.h>
 #include <stdbool.h>
+#include "rwonce.h"
 
 /************ originally in <include/linux/types.h> */
 struct list_head {
@@ -23,12 +25,18 @@ struct hlist_node {
 };
 
 /************ originally in <include/linux/poison.h> */
-#define LIST_POISON1  ((void *) 0x100)
-#define LIST_POISON2  ((void *) 0x122)
+# define POISON_POINTER_DELTA 0
+/* These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x100 + POISON_POINTER_DELTA)
+#define LIST_POISON2  ((void *) 0x200 + POISON_POINTER_DELTA)
 
 /************ originally in <include/linux/kernel.h> */
-#define container_of(ptr, type, member) \
-    ((type *)((char *)(ptr) - offsetof(type, member)))
+#define container_of(ptr, type, member) ({				\
+	void *__mptr = (void *)(ptr);					\
+	((type *)(__mptr - offsetof(type, member))); })
 
 /*
  * Circular doubly linked list implementation.
@@ -54,7 +62,7 @@ struct hlist_node {
  */
 static inline void INIT_LIST_HEAD(struct list_head *list)
 {
-    list->next = list;
+    WRITE_ONCE(list->next, list);
     list->prev = list;
 }
 
@@ -71,7 +79,7 @@ static inline void __list_add(struct list_head *new,
     next->prev = new;
     new->next  = next;
     new->prev  = prev;
-    prev->next = new;
+    WRITE_ONCE(prev->next, new);
 }
 
 /**
@@ -111,7 +119,7 @@ static inline void list_add_tail(struct list_head *new, struct list_head *head)
 static inline void __list_del(struct list_head * prev, struct list_head * next)
 {
     next->prev = prev;
-    prev->next = next;
+    WRITE_ONCE(prev->next, next);
 }
 
 /*
@@ -277,7 +285,7 @@ static inline int list_is_last(const struct list_head *list,
  */
 static inline int list_empty(const struct list_head *head)
 {
-    return head->next == head;
+    return READ_ONCE(head->next) == head;
 }
 
 /**
@@ -503,7 +511,7 @@ static inline void list_splice_tail_init(struct list_head *list,
  */
 #define list_first_entry_or_null(ptr, type, member) ({                  \
             struct list_head *head__ = (ptr);                           \
-            struct list_head *pos__ = head__->next;                     \
+            struct list_head *pos__ = READ_ONCE(head__->next);          \
             pos__ != head__ ? list_entry(pos__, type, member) : NULL;   \
         })
 
@@ -779,7 +787,7 @@ static inline int hlist_unhashed(const struct hlist_node *h)
  */
 static inline int hlist_unhashed_lockless(const struct hlist_node *h)
 {
-    return !h->pprev;
+    return !READ_ONCE(h->pprev);
 }
 
 /**
@@ -788,7 +796,7 @@ static inline int hlist_unhashed_lockless(const struct hlist_node *h)
  */
 static inline int hlist_empty(const struct hlist_head *h)
 {
-    return !h->first;
+    return !READ_ONCE(h->first);
 }
 
 static inline void __hlist_del(struct hlist_node *n)
@@ -796,9 +804,9 @@ static inline void __hlist_del(struct hlist_node *n)
     struct hlist_node *next = n->next;
     struct hlist_node **pprev = n->pprev;
 
-    *pprev = next;
+    WRITE_ONCE(*pprev, next);
     if (next)
-        next->pprev = pprev;
+        WRITE_ONCE(next->pprev, pprev);
 }
 
 /**
@@ -840,11 +848,11 @@ static inline void hlist_del_init(struct hlist_node *n)
 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
 {
     struct hlist_node *first = h->first;
-    n->next = first;
+    WRITE_ONCE(n->next, first);
     if (first)
-        first->pprev = &n->next;
-    h->first = n;
-    n->pprev = &h->first;
+        WRITE_ONCE(first->pprev, &n->next);
+    WRITE_ONCE(h->first, n);
+    WRITE_ONCE(n->pprev, &h->first);
 }
 
 /**
@@ -855,10 +863,10 @@ static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
 static inline void hlist_add_before(struct hlist_node *n,
 				    struct hlist_node *next)
 {
-    n->pprev    = next->pprev;
-    n->next     = next;
-    next->pprev = &n->next;
-    *(n->pprev) = n;
+    WRITE_ONCE(n->pprev, next->pprev);
+    WRITE_ONCE(n->next, next);
+    WRITE_ONCE(next->pprev, &n->next);
+    WRITE_ONCE(*(n->pprev), n);
 }
 
 /**
@@ -869,12 +877,12 @@ static inline void hlist_add_before(struct hlist_node *n,
 static inline void hlist_add_behind(struct hlist_node *n,
 				    struct hlist_node *prev)
 {
-    n->next = prev->next;
-    prev->next = n;
-    n->pprev = &prev->next;
+    WRITE_ONCE(n->next, prev->next);
+    WRITE_ONCE(prev->next, n);
+    WRITE_ONCE(n->pprev, &prev->next);
 
     if (n->next)
-        n->next->pprev = &n->next;
+        WRITE_ONCE(n->next->pprev, &n->next);
 }
 
 /**
@@ -953,7 +961,7 @@ static inline void hlist_move_list(struct hlist_head *old,
 #define hlist_for_each_entry(pos, head, member)				\
     for (pos = hlist_entry_safe((head)->first, __typeof__(*(pos)), member); \
          pos;                                                           \
-         pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
+         pos = hlist_entry_safe((pos)->member.next, __typeof__(*(pos)), member))
 
 /**
  * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
@@ -961,9 +969,9 @@ static inline void hlist_move_list(struct hlist_head *old,
  * @member:	the name of the hlist_node within the struct.
  */
 #define hlist_for_each_entry_continue(pos, member)			\
-    for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member); \
+    for (pos = hlist_entry_safe((pos)->member.next, __typeof__(*(pos)), member); \
          pos;                                                           \
-         pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
+         pos = hlist_entry_safe((pos)->member.next, __typeof__(*(pos)), member))
 
 /**
  * hlist_for_each_entry_from - iterate over a hlist continuing from current point
@@ -972,7 +980,7 @@ static inline void hlist_move_list(struct hlist_head *old,
  */
 #define hlist_for_each_entry_from(pos, member)				\
     for (; pos;                                                         \
-         pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
+         pos = hlist_entry_safe((pos)->member.next, __typeof__(*(pos)), member))
 
 /**
  * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
@@ -982,8 +990,8 @@ static inline void hlist_move_list(struct hlist_head *old,
  * @member:	the name of the hlist_node within the struct.
  */
 #define hlist_for_each_entry_safe(pos, n, head, member) 		\
-    for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);   \
+    for (pos = hlist_entry_safe((head)->first, __typeof__(*pos), member);   \
          pos && ({ n = pos->member.next; 1; });                         \
-         pos = hlist_entry_safe(n, typeof(*pos), member))
+         pos = hlist_entry_safe(n, __typeof__(*pos), member))
 
-#endif
+#endif  /* __BR_LIST_H */

c/pool.c

@@ -0,0 +1,225 @@
+/* pool.c - A simple pool manager.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stddef.h>
+#include <malloc.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include "list.h"
+#include "pool.h"
+#include "debug.h"
+#include "bits.h"
+
+void pool_stats(pool_t *pool)
+{
+    if (pool) {
+#       ifdef DEBUG_POOL
+        block_t *block;
+
+        log_f(1, "[%s] pool [%p]: blocks:%u avail:%u alloc:%u grow:%u eltsize:%lu\n",
+              pool->name, (void *)pool, pool->nblocks, pool->available, pool->allocated,
+              pool->growsize, pool->eltsize);
+        log(5, "\tblocks: ");
+        list_for_each_entry(block, &pool->list_blocks, list_blocks) {
+            log(5, "%p ", block);
+        }
+        log(5, "\n");
+#       endif
+    }
+}
+
+pool_t *pool_create(const char *name, u32 growsize, size_t eltsize)
+{
+    pool_t *pool;
+
+#   ifdef DEBUG_POOL
+    log_f(1, "name=[%s] growsize=%u eltsize=%lu\n",
+          name, growsize, eltsize);
+#   endif
+    /* we need at least  sizeof(struct list_head) space in pool elements
+     */
+    if (eltsize < sizeof (struct list_head)) {
+#       ifdef DEBUG_POOL
+        log_f(1, "[%s]: structure size too small (%lu < %lu), adjusting to %lu.\n",
+              name, eltsize, sizeof(struct list_head), sizeof(struct list_head));
+#       endif
+        eltsize = sizeof(struct list_head);
+    }
+    if ((pool = malloc(sizeof (*pool)))) {
+        strncpy(pool->name, name, POOL_NAME_LENGTH - 1);
+        pool->name[POOL_NAME_LENGTH - 1] = 0;
+        pool->growsize = growsize;
+        pool->eltsize = eltsize;
+        pool->available = 0;
+        pool->allocated = 0;
+        pool->nblocks = 0;
+        INIT_LIST_HEAD(&pool->list_available);
+        INIT_LIST_HEAD(&pool->list_blocks);
+    }
+    return pool;
+}
+
+static u32 _pool_add(pool_t *pool, struct list_head *elt)
+{
+#   ifdef DEBUG_POOL
+    log_f(6, "pool=%p &head=%p elt=%p off1=%lu off2=%lu\n",
+          (void *)pool,
+          (void *)&pool->list_available,
+          (void *)elt,
+          (void *)&pool->list_available-(void *)pool,
+          offsetof(pool_t, list_available));
+#   endif
+
+    list_add(elt, &pool->list_available);
+    return ++pool->available;
+}
+
+u32 pool_add(pool_t *pool, void *elt)
+{
+    return _pool_add(pool, elt);
+}
+
+static struct list_head *_pool_get(pool_t *pool)
+{
+    struct list_head *res = pool->list_available.next;
+    pool->available--;
+    list_del(res);
+    return res;
+}
+
+void *pool_get(pool_t *pool)
+{
+    if (!pool)
+        return NULL;
+    if (!pool->available) {
+        block_t *block = malloc(sizeof(block_t) + pool->eltsize * pool->growsize);
+        void *cur;
+        u32 i;
+
+        if (!block) {
+#           ifdef DEBUG_POOL
+            log_f(1, "[%s]: failed block allocation\n", pool->name);
+#           endif
+            errno = ENOMEM;
+            return NULL;
+        }
+
+        /* maintain list of allocated blocks
+         */
+        list_add(&block->list_blocks, &pool->list_blocks);
+        pool->nblocks++;
+
+#       ifdef DEBUG_POOL
+        log_f(1, "[%s]: growing pool from %u to %u elements. block=%p nblocks=%u\n",
+              pool->name,
+              pool->allocated,
+              pool->allocated + pool->growsize,
+              block,
+              pool->nblocks);
+#       endif
+
+        pool->allocated += pool->growsize;
+        for (i = 0; i < pool->growsize; ++i) {
+            cur = block->data + i * pool->eltsize;
+#           ifdef DEBUG_POOL
+            log_f(7, "alloc=%p cur=%p\n", block, cur);
+#           endif
+            _pool_add(pool, (struct list_head *)cur);
+        }
+        //pool_stats(pool);
+    }
+    /* this is the effective address if the object (and also the
+     * pool list_head address)
+     */
+    return _pool_get(pool);
+}
+
+void pool_destroy(pool_t *pool)
+{
+    block_t *block, *tmp;
+    if (!pool)
+        return;
+    /* release memory blocks */
+#   ifdef DEBUG_POOL
+    log_f(1, "[%s]: releasing %d blocks and main structure\n", pool->name, pool->nblocks);
+    log(5, "blocks:");
+#   endif
+    list_for_each_entry_safe(block, tmp, &pool->list_blocks, list_blocks) {
+        list_del(&block->list_blocks);
+        free(block);
+#       ifdef DEBUG_POOL
+        log(5, " %p", block);
+#       endif
+    }
+#   ifdef DEBUG_POOL
+    log(5, "\n");
+#   endif
+    free(pool);
+}
+
+#ifdef BIN_pool
+struct d {
+    u16 data1;
+    char c;
+    struct list_head list;
+};
+
+static LIST_HEAD (head);
+
+int main(int ac, char**av)
+{
+    pool_t *pool;
+    int total;
+    int action=0;
+    u16 icur=0;
+    char ccur='z';
+    struct d *elt;
+
+    debug_init(3);
+    log_f(1, "%s: sizeof(d)=%lu sizeof(*d)=%lu off=%lu\n", *av, sizeof(elt),
+          sizeof(*elt), offsetof(struct d, list));
+
+    if ((pool = pool_create("dummy", 3, sizeof(*elt)))) {
+        pool_stats(pool);
+        for (int cur=1; cur<ac; ++cur) {
+            total = atoi(av[cur]);
+            if (action == 0) {                    /* add elt to list */
+                log_f(2, "adding %d elements\n", total);
+                for (int i = 0; i < total; ++i) {
+                    elt = pool_get(pool);
+                    elt->data1 = icur++;
+                    elt->c = ccur--;
+                    list_add(&elt->list, &head);
+                }
+                pool_stats(pool);
+                action = 1;
+            } else {                              /* remove one elt from list */
+                log_f(2, "deleting %d elements\n", total);
+                for (int i = 0; i < total; ++i) {
+                    if (!list_empty(&head)) {
+                        elt = list_last_entry(&head, struct d, list);
+                        printf("elt=[%d, %c]\n", elt->data1, elt->c);
+                        list_del(&elt->list);
+                        pool_add(pool, elt);
+                    }
+                }
+                pool_stats(pool);
+                action = 0;
+            }
+        }
+    }
+    pool_stats(pool);
+}
+#endif

c/pool.h

@@ -0,0 +1,77 @@
+/* pool.h - A simple memory pool manager.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef POOL_H
+#define POOL_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include "list.h"
+#include "bits.h"
+
+#define POOL_NAME_LENGTH (16)                     /* max name length including trailing \0 */
+
+typedef struct {
+    struct list_head list_blocks;                 /* list of allocated blocks in pool */
+    char data[];                                  /* objects block */
+} block_t;
+
+typedef struct {
+    char name[POOL_NAME_LENGTH];                  /* pool name */
+    u32 available;                                /* current available elements */
+    u32 allocated;                                /* total objects allocated */
+    u32 growsize;                                 /* number of objects per block allocated */
+    size_t eltsize;                               /* object size */
+    u32 nblocks;                                  /* number of blocks allocated */
+    struct list_head list_available;              /* available nodes */
+    struct list_head list_blocks;                 /* allocated blocks */
+} pool_t;
+
+/**
+ * pool_stats - display some pool statistics
+ * @pool:    the pool address.
+ */
+void pool_stats(pool_t *pool);
+
+/**
+ * pool_create - create a new memory pool
+ * @name:    the name to give to the pool.
+ * @grow:    the number of elements to add when no more available.
+ * @size:    the size of an element in pool.
+ */
+pool_t *pool_create(const char *name, u32 grow, size_t size);
+
+/**
+ * pool_get - get an element from a pool
+ * @pool:    the pool address.
+ */
+void *pool_get(pool_t *pool);
+
+/**
+ * pool_add - add (release) an element to a pool
+ * @pool:    the pool address.
+ * @elt:     the address of the object to add to the pool.
+ */
+u32 pool_add(pool_t *pool, void *elt);
+
+/**
+ * pool_destroy - destroy a pool.
+ * @pool:    the pool address.
+ *
+ * Attention: All memory is freed, but no check is done whether all pool
+ * elements has been released. Referencing any pool object after this call
+ * is strongly discouraged.
+ */
+void pool_destroy(pool_t *pool);
+
+#endif

c/rwonce.h

@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* adaptation of kernel's <asm-generic/rwonce.h>
+ * See https://www.kernel.org/doc/Documentation/memory-barriers.txt
+ */
+/*
+ * Prevent the compiler from merging or refetching reads or writes. The
+ * compiler is also forbidden from reordering successive instances of
+ * READ_ONCE and WRITE_ONCE, but only when the compiler is aware of some
+ * particular ordering. One way to make the compiler aware of ordering is to
+ * put the two invocations of READ_ONCE or WRITE_ONCE in different C
+ * statements.
+ *
+ * These two macros will also work on aggregate data types like structs or
+ * unions.
+ *
+ * Their two major use cases are: (1) Mediating communication between
+ * process-level code and irq/NMI handlers, all running on the same CPU,
+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
+ * mutilate accesses that either do not require ordering or that interact
+ * with an explicit memory barrier or atomic instruction that provides the
+ * required ordering.
+ */
+#ifndef __BR_RWONCE_H
+#define __BR_RWONCE_H
+
+/************ originally in <include/linux/compiler_types.h> */
+# define __compiletime_error(message) __attribute__((error(message)))
+
+/************ originally in <include/linux/compiler_types.h> */
+/*
+ * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
+ *                             non-scalar types unchanged.
+ */
+/*
+ * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
+ * is not type-compatible with 'signed char', and we define a separate case.
+ */
+#define __scalar_type_to_expr_cases(type)                               \
+    unsigned type:  (unsigned type)0,                                   \
+    signed type:    (signed type)0
+
+#define __unqual_scalar_typeof(x)                                       \
+    typeof(_Generic((x),                                                \
+                    char:  (char)0,                                     \
+                    __scalar_type_to_expr_cases(char),                  \
+                    __scalar_type_to_expr_cases(short),                 \
+                    __scalar_type_to_expr_cases(int),                   \
+                    __scalar_type_to_expr_cases(long),                  \
+                    __scalar_type_to_expr_cases(long long),             \
+                    default: (x)))
+
+/* Is this type a native word size -- useful for atomic operations */
+#define __native_word(t) \
+    (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
+     sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
+
+#ifdef __OPTIMIZE__
+# define __compiletime_assert(condition, msg, prefix, suffix)           \
+    do {                                                                \
+        extern void prefix ## suffix(void) __compiletime_error(msg);    \
+        if (!(condition))                                               \
+            prefix ## suffix();                                         \
+    } while (0)
+#else
+# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
+#endif
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+    __compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg:       a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg)                              \
+    _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
+
+#define compiletime_assert_atomic_type(t)                               \
+    compiletime_assert(__native_word(t),                                \
+                       "Need native word sized stores/loads for atomicity.")
+
+/************ originally in <asm-generic/rwonce.h> */
+/*
+ * Yes, this permits 64-bit accesses on 32-bit architectures. These will
+ * actually be atomic in some cases (namely Armv7 + LPAE), but for others we
+ * rely on the access being split into 2x32-bit accesses for a 32-bit quantity
+ * (e.g. a virtual address) and a strong prevailing wind.
+ */
+#define compiletime_assert_rwonce_type(t)                                  \
+    compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
+                       "Unsupported access size for {READ,WRITE}_ONCE().")
+
+/*
+ * Use __READ_ONCE() instead of READ_ONCE() if you do not require any
+ * atomicity. Note that this may result in tears!
+ */
+#ifndef __READ_ONCE
+#define __READ_ONCE(x)  (*(const volatile __unqual_scalar_typeof(x) *)&(x))
+#endif
+
+#define READ_ONCE(x)                                                    \
+({                                                                      \
+    compiletime_assert_rwonce_type(x);                                  \
+    __READ_ONCE(x);                                                     \
+})
+
+#define __WRITE_ONCE(x, val)                                            \
+do {                                                                    \
+    *(volatile typeof(x) *)&(x) = (val);                                \
+} while (0)
+
+#define WRITE_ONCE(x, val)                                              \
+do {                                                                    \
+    compiletime_assert_rwonce_type(x);                                  \
+    __WRITE_ONCE(x, val);                                               \
+} while (0)
+
+#endif  /* __BR_RWONCE_H */