Introduce Initialize_Last_SysTarget_Snapshot() function

[backup-script.git] / bin / backup-script

diff --git a/bin/backup-script b/bin/backup-script
index 85b62a8d8c8085ce4886167c362a1ae13f7f894e..8da13700f2c790a323f4e5558588da531a6ae8ce 100755 (executable)
--- a/bin/backup-script
+++ b/bin/backup-script
@@ -76,8 +76,8 @@ GotSignal() {
 }
 
 ExecJob() {
-       what="$1"
-       cmd="$2"
+       local what="$1"
+       local cmd="$2"
 
        echo "Running job ${what}-exec command ..."
        [ "$local" -eq 0 ] \
@@ -85,7 +85,7 @@ ExecJob() {
        echo -n "Start date (${what}-exec): "; date
        echo "$cmd"
        if [ "$DRYRUN" -eq 0 ]; then
-               $SHELL -c "$cmd"; ret=$?
+               $SHELL -c "$cmd"; local ret=$?
        else
                echo " *** Trial run, not executing ${what}-exec command!"
                ret=0
@@ -97,9 +97,10 @@ ExecJob() {
 }
 
 GetFS() {
-       dir="$1"
+       local dir="$1"
+
        while [ -n "$dir" ]; do
-               findmnt -fn -o FSTYPE --raw "$dir" 2>/dev/null; r=$?
+               findmnt -fn -o FSTYPE --raw "$dir" 2>/dev/null; local r=$?
                if [ $r -eq 0 ]; then
                        return 0
                elif [ $r -eq 127 ]; then
@@ -111,7 +112,9 @@ GetFS() {
 }
 
 CreateSubvolume() {
-       volume="$1"
+       local volume="$1"
+       local fs
+       local dir
 
        dir=$(dirname "$volume")
        fs=$(GetFS "$dir")
@@ -127,14 +130,17 @@ CreateSubvolume() {
 }
 
 CloneSubvolume() {
-       source="$1"
-       volume="$2"
+       local source="$1"
+       local volume="$2"
+       local snapshot="$3"
+       local dir
+       local fs
 
        dir=$(dirname "source")
        fs=$(GetFS "$source")
        case "$fs" in
          "btrfs")
-               btrfs subvolume snapshot "$source" "$volume"  >/dev/null || return 1
+               btrfs subvolume snapshot "$source" "$snapshot"  >/dev/null || return 1
                ;;
          *)
                echo "CloneSubvolume: Incompatible FS type \"$fs\" on \"$source\"!"
@@ -144,8 +150,9 @@ CloneSubvolume() {
 }
 
 RenameSubvolume() {
-       source="$1"
-       target="$2"
+       local source="$1"
+       local target="$2"
+       local fs
 
        fs=$(GetFS "$source")
        case "$fs" in
@@ -160,7 +167,8 @@ RenameSubvolume() {
 }
 
 DeleteSubvolume() {
-       volume="$1"
+       local volume="$1"
+       local fs
 
        fs=$(GetFS "$source")
        case "$fs" in
@@ -174,6 +182,33 @@ DeleteSubvolume() {
        return 0
 }
 
+Initialize_Last_SysTarget_Snapshot() {
+       sys_target="$1"
+       unset last
+       unset snapshot
+
+       fs=$(GetFS "$sys_target")
+       case "$fs" in
+         "btrfs")
+               # Search directory of last generation, if any
+               last=$(ls -1d "$sys_target"/[0-9]* 2>/dev/null | sort -r | head -n1)
+               if [ -n "$last" ]; then
+                       if [ ! -d "$last" ]; then
+                               echo "Last snapshot \"$last\" seems not to be a directory!? \"$system\" skipped!"
+                               echo
+                               return 1
+                       fi
+               fi
+               sys_target="$sys_target/$(date +%Y%m%d-%H%M%S)"
+               snapshot="$sys_target"
+               ;;
+         *)
+               echo "Initialize_Last_SysTarget_Snapshot: Incompatible FS type \"$fs\" on \"$sys_target\"!"
+               return 1
+       esac
+       return 0
+}
+
 while [ $# -gt 0 ]; do
        case "$1" in
          "-n"|"--dry-run")
@@ -269,9 +304,33 @@ for f in $sys; do
        job_pre_exec="$default_job_pre_exec"
        job_post_exec="$default_job_post_exec"
 
+       # Compatibility with backup-pull(1) script: Save global values ...
+       pre_exec_saved="$pre_exec"
+       post_exec_saved="$post_exec"
+
+       # Compatibility with backup-pull(1) script: Set defaults
+       unset host
+       unset source
+       unset pre_exec
+       unset post_exec
+
        # Read in system configuration file
        source "$f"
 
+       # Compatibility with backup-pull(1) script: Fix up configuration
+       [ "$system" = "$fname" -a -n "$host" ] \
+               && system="$host"
+       [ "$source_root" = "$default_source_root" -a -n "$source" ] \
+               && source_root="$source"
+       [ -z "$job_pre_exec" -a -n "$pre_exec" ] \
+               && job_pre_exec="$pre_exec"
+       [ -z "$job_post_exec" -a -n "$post_exec" ] \
+               && job_post_exec="$post_exec"
+
+       # Compatibility with backup-pull(1) script: Restore global values ...
+       pre_exec="$pre_exec_saved"
+       post_exec="$post_exec_saved"
+
        # Validate configuration
        [ "$system" = "localhost" -o "$system" = "127.0.0.1" ] && local=1
 
@@ -323,15 +382,7 @@ for f in $sys; do
                        echo; continue
                fi
 
-               # Search directory of last generation, if any
-               last=$(ls -1d "$sys_target"/[0-9]* 2>/dev/null | sort -r | head -n1)
-               if [ -n "$last" ]; then
-                       if [ ! -d "$last" ]; then
-                               echo "Last snapshot \"$last\" seems not to be a directory!? \"$system\" skipped!"
-                               echo; continue
-                       fi
-               fi
-               sys_target="$sys_target/$(date +%Y%m%d-%H%M%S)"
+               Initialize_Last_SysTarget_Snapshot "$sys_target" || continue
 
                if [ -n "$last" -a ! -e "$last/.stamp" ]; then
                        # Old backup directory without "stamp file", continue
@@ -345,12 +396,12 @@ for f in $sys; do
                        # Old backup directory found, create new snapshot
                        echo "Found last snapshot in \"$last\"."
                        if [ "$DRYRUN" -eq 0 ]; then
-                               CloneSubvolume "$last" "$sys_target"; r=$?
+                               CloneSubvolume "$last" "$sys_target" "$snapshot"; r=$?
                                if [ $r -ne 0 ]; then
-                                       echo "Can't create snapshot \"$sys_target\" of \"$last\", code $r!? \"$system\" skipped!"
+                                       echo "Can't create snapshot \"$snapshot\" of \"$last\", code $r!? \"$system\" skipped!"
                                        echo; continue
                                fi
-                               echo "Created new snapshot in \"$sys_target\"."
+                               echo "Created new snapshot in \"$snapshot\"."
                        else
                                echo " *** Trial run, not creating new snapshot in \"$sys_target\"!"
                        fi
@@ -406,7 +457,7 @@ for f in $sys; do
        echo "$cmd"
        count_started=$count_started+1
        ok=0
-       
+
        if [ "$DRYRUN" -eq 0 ]; then
                rm -f "$sys_target/.stamp"
                $SHELL -c "$cmd"; ret=$?
@@ -445,10 +496,11 @@ for f in $sys; do
                        ln -s "$sys_target" "$sys_root/latest"
                fi
                # Clean up old generations
-               to_delete=$(ls -1t "$sys_root" 2>/dev/null | tail -n+$generations | sort)
+               declare -i gen_count=$generations+2
+               to_delete=$(ls -1t "$sys_root" 2>/dev/null | tail -n+$gen_count | sort)
                if [ -n "$to_delete" -a $ok -eq 1 ]; then
                        [ "$DRYRUN" -eq 0 ] \
-                               && echo "Deleting old backup generations:" \
+                               && echo "Deleting old backup generations (keep $generations) ..." \
                                || echo " *** Trial run, not deleting old generations:"
                        for delete in $to_delete; do
                                dir="$sys_root/$delete"