BEE Backport bacula/src/filed/fd_snapshot.c

This commit is the result of the squash of the following main commits:

Author: Eric Bollengier <eric@baculasystems.com>
Date:   Thu Apr 9 21:55:29 2020 +0200

    Tweak comment

Author: Alain Spineux <alain@baculasystems.com>
Date:   Mon Nov 12 11:07:04 2018 +0100

    win32: Fix #4286 about the restore of a volume root directory with the hidden & system attributes

    - Detect root directories like C:\ or C:\mount_point
      and setup st_rdev=WIN32_ROOT_POINT to tell restore to not restore
      the hidden and system attributes
    - Be aware that there is 2 different "directories" (1) the parent
      directory like c:\mount_point and (2) the root directory of the volume
      that your are attaching to the parent. The attributes that you see is
      the attribute of (1) but for drive letters, their is no (1) then
      you see always (2) (that are hidden and system).
      When VSS snapshot is used

Author: Alain Spineux <alain@baculasystems.com>
Date:   Tue Aug 28 17:14:31 2018 +0200

    snapshot: maintain both paths instead of stripping and unstripping

    - snap_fname is the path inside the snapshot used for "system" operation
    - fname is the path from the FileSet used for display and for SD or DIR
      "computation"
    - when snapshot is not in used, both are equal

Author: Alain Spineux <alain@baculasystems.com>
Date:   Fri Aug 24 14:14:43 2018 +0200

    snapshot: create bsnapshot.log in {working} instead of /tmp directory

Author: Eric Bollengier <eric@baculasystems.com>
Date:   Wed Jul 25 17:28:42 2018 +0200

    snapshot: Add mountopts bsnapshot.conf option

    $ cat bsnapshot.conf
    mountopts=noexec,nodev             <---  default
    mountopts=/dev/vgroot/root:nouuid            <---- for one device
    mountopts=/dev/vgroot/home:nouuid,uid=backup <---- for one device

Author: Alain Spineux <alain@baculasystems.com>
Date:   Mon Mar 26 18:23:06 2018 +0200

    win32: update compat.cpp "file" functions to use new path functions

    - statDir
    - stat 2
    - GetApplicationName
    - win32_chmod win32_chdir win32_mkdir
    - win32_getcwd file_open utime
    - symlink
    - stat
    - breaddir
    - opendir

Author: Eric Bollengier <eric@baculasystems.com>
Date:   Thu Feb 5 09:42:01 2015 +0100

    Add Snapshot Engine to bacula core

            Rename jcr->VSS to jcr->Snapshot and use the same variable on Linux/Windows
            Pass snapshot retention to the FD
            Add SnapshotRetention to client and job resource
            Add documentation about snapshot backend
            regress: Add snapshot script for lvm backend
            Use retry in lvm unmount procedure
            Read config file from sysconfigdir
            Load bsnapshot.cfg by default and configure bsnapshot using exepath
            Add config file to specify lvm snapshot parameters
            Control LVM free space for snapshot
            Implement OT_PINT64 in output writer, should display job speed api2 mode status command
            regress: Add test to test snapshot bconsole commands
            regress: Add test for zfs snapshot
            implement zfs driver (linux zfs driver cannot mount snapshots)
            regress: Add regress script for snapshots
            Include automatically subvolumes with onefs=no
            Handle ff->link in strip snapshot path
            Scan for subvolumes not listed in mtab
            Snapshots can be created/deleted from the catalog
            Implement path translation between snapshot
            Add JobId to Snapshot table
            Add code to execute snapshot script on the FD side
            Add more Director snapshots command
            Implement CatReq interface for Snapshots
            Implement DB snapshot functions
            the delete snapshot is now connecting to the FD, and the
            FD is calling the snapshot script with the delete argument
            Allow to specify env variable in run_command_full_output() and open_bpipe()
            Modify cmd_parser to not look for plugin name with use_name option
            Add ARG_LIST to generate nice arg1=arg2 output from db_list function
            Add tag DT_SNAPSHOT
            Add JobId in the list snapshot output
            Add list snapshot command
            Add JobId to snapshot table

diff --git a/bacula/src/filed/fd_snapshot.c b/bacula/src/filed/fd_snapshot.c
index 12a797d8c561ad45470dabbf702d933230eb4936..e55db9378f568738202187d455bd06cc465a37c6 100644 (file)
--- a/bacula/src/filed/fd_snapshot.c
+++ b/bacula/src/filed/fd_snapshot.c
@@ -15,11 +15,16 @@
    conveyed and/or propagated.
 
    Bacula(R) is a registered trademark of Kern Sibbald.
+   Bacula Systems(R) is a trademark of Bacula Systems SA.
+   Bacula Enterprise(TM) is a trademark of Bacula Systems SA.
 
-   Written by Eric Bollengier, 2015
+   The licensor of Bacula Enterprise(TM) is Bacula Systems(R) SA,
+   Rue Galilee 5, 1400 Yverdon-les-Bains, Switzerland.
 */
 
 /*
+   Written by Eric Bollengier, 2015
+
            Documentation about snapshot backend
 ----------------------------------------------------------------
 
@@ -404,6 +409,7 @@ public:
 
    /* Get subvolumes for a specific device */
    bool get_subvolumes(uint32_t dev, alist *items, FF_PKT *ff) {
+      int l, l2;
       fs_device *elt, *elt2;
       elt = (fs_device *)entries->search((void*)(intptr_t)dev, search_entry);
       if (!elt) {
@@ -414,10 +420,14 @@ public:
          if (elt2->dev == elt->dev) {
             continue;
          }
-         if (strncmp(elt2->mountpoint, elt->mountpoint, strlen(elt->mountpoint)) == 0) {
-            /* the mount point is included in the volume */
+         l = strlen(elt->mountpoint);
+         if (strncmp(elt2->mountpoint, elt->mountpoint, l) == 0) {
+            l2 = strlen(elt2->mountpoint);
+            if (l2 > l && !IsPathSeparator(elt2->mountpoint[l])) {
+               Dmsg1(DT_SNAPSHOT|50, "Not subvolume %s\n", elt2->mountpoint);
 
-            if (file_is_excluded(ff, elt2->mountpoint)) {
+            } else if (file_is_excluded(ff, elt2->mountpoint)) {
+            /* the mount point is included in the volume */
                Dmsg1(DT_SNAPSHOT|50, "Looks to be excluded %s\n", elt2->mountpoint);
 
             } else {
@@ -591,7 +601,6 @@ public:
 
       pm_strcat(ff->snap_top_fname, ff->top_fname + mp_first);
       ff->top_fname = ff->snap_top_fname;
-      ff->strip_snap_path = true;
       Dmsg1(DT_SNAPSHOT|50, "top_fname=%s\n", ff->top_fname);
       return true;
    };
@@ -714,7 +723,7 @@ public:
 
       if (chk_dbglvl(DT_SNAPSHOT|10)) {
          POOL_MEM tmp;
-         Mmsg(tmp, " -d %d -o /tmp/bsnapshot.log ", debug_level);
+         Mmsg(tmp, " -d %d -o %s/bsnapshot.log ", debug_level, working_directory);
          pm_strcat(omsg, tmp.c_str());
       }
 
@@ -828,6 +837,7 @@ public:
 
          } else if (strcasecmp(cmd->argk[i], "SnapDirectory") == 0 && cmd->argv[i]) {
             pm_strcpy(SnapDirectory, cmd->argv[i]);
+            strip_trailing_slashes(SnapDirectory);
 
          } else if (strcasecmp(cmd->argk[i], "status") == 0 && cmd->argv[i]) {
             status = str_to_int64(cmd->argv[i]);
@@ -1485,7 +1495,7 @@ bool snapshot_manager::create_snapshots()
                /* Set the Exclude context */
                set_incexe(jcr, exclude);
             }
-            Mmsg(t, "%s/.snapshots", elt->snap->SnapMountPoint);
+            Mmsg(t, "%s", elt->snap->SnapDirectory);
             Dmsg1(DT_SNAPSHOT|10, "Excluding %s\n", t.c_str());
             add_file_to_fileset(jcr, t.c_str(), true);
          }
@@ -1626,7 +1636,9 @@ bool snapshot_manager::scan_mtab()
 }
 
 
-/* Scan the fileset to select partitions to snapshot */
+/* Scan the fileset to select the volumes to snapshot (and subvolumes when
+ * FO_MULTIFS is used) but also extend the FileSet to walk these subvolumes
+ * that are not anymore in the same tree as their parent */
 bool snapshot_manager::scan_fileset()
 {
    if (!jcr->ff || !jcr->ff->fileset) {
@@ -1646,6 +1658,7 @@ bool snapshot_manager::scan_fileset()
       /* look through all files */
       foreach_dlist(node, &incexe->name_list) {
          char *fname = node->c_str();
+         Dmsg1(DT_SNAPSHOT|20, "Inspect %s for sub volume to mark for the snapshot\n", fname);
          if (mount_list->add_in_snapshot_set(fname, &incexe->name_list, node)) {
             /* When all volumes are selected, we can stop */
             Dmsg0(DT_SNAPSHOT, "All Volumes are marked, stopping the loop here\n");
@@ -1677,8 +1690,10 @@ all_included:
             }
 
             /* TODO: See how to avoid having two entries for the same directory */
-            /* Add the directory explicitely in the fileset */
+            /* Add the directory explicitly in the fileset (elt->include is a */
+            /* pointer to the FileSet->include_list->name_list) */
             elt->include->insert_after(new_dlistString(elt2->mountpoint), elt->node);
+            Dmsg1(DT_SNAPSHOT|20, "Add a sub volume to the FileSet: %s\n", elt2->mountpoint);
 
             if (mount_list->add_in_snapshot_set(elt2, elt->include, elt->node)) {
                /* When all volumes are selected, we can stop */
@@ -1783,11 +1798,91 @@ bail_out:
    return ret;
 }
 
+
+#ifdef HAVE_WIN32
+BOOL VSSPathConvertW(const wchar_t *szFilePath, wchar_t *szShadowPath, int nBuflen);
+
+/* This function is called by find_files(), once for every "Include" entries
+ * in the FileSet.
+ * This function must redirect "ff->top_fname" to its snapshot version if it
+ * exists
+ */
+bool snapshot_convert_path(JCR *jcr, FF_PKT *ff, dlist *filelist, dlistString *node)
+{
+   Dmsg1(DT_SNAPSHOT, "snapshot_convert_path(%s)\n", ff->top_fname);
+   // FYI jcr->snap_mgr==NULL because Win32 use VSSClient instead
+
+   /* Convert the filename to the original path */
+   /* get the path of "ff->top_fname" inside the snapshots */
+   // convert to Windows wchar_t path
+   POOL_MEM wpath(PM_FNAME);
+   POOL_MEM wsnap(PM_FNAME);
+   make_win32_path_UTF8_2_wchar(&wpath.addr(), ff->top_fname);
+   wchar_t *p = (wchar_t *)wpath.c_str();
+   Dmsg2(10, "ASX Convert wchart %s => %ls\n", ff->top_fname, p);
+   DWORD len = wcslen(p);
+#if 0
+   // remove any trailing '/' or '\\'
+      while (IsWPathSeparator(p[len-1])) {
+         len--;
+         p[len]=L'\0';
+      }
+      Dmsg2(10, "ASX Convert wchart %s => %ls\n", ff->top_fname, p);
+#endif
+   // get the snapshot path
+   len+=MAX_PATH; // allocate enough space for "GLOBALROOT\Device\HarddiskVolumeShadowCopyXXX"
+   wsnap.check_size(2*len);
+   BOOL vss_exist=VSSPathConvertW((wchar_t *)&wpath.c_str()[8], (wchar_t *)wsnap.c_str(), len); // 8 == skip r"\\?\" prefix
+   if (!vss_exist) {
+      return true;
+   }
+   // Their is a snapshot for this path, I'll need some buffers
+   if (!ff->snap_top_fname) {
+      ff->snap_top_fname = get_pool_memory(PM_FNAME);
+   }
+   // convert back to utf8
+   wchar_path_2_wutf8(&ff->snap_top_fname, (wchar_t *)wsnap.c_str());
+   // end convert Windows '\' into posix '/'
+   char *q=ff->snap_top_fname;
+   while (*q) {
+      if (*q=='\\') {
+         *q='/';
+      }
+      q++;
+   }
+   ff->root_of_volume = false;
+   // add a trailing '\' to snap_top_fname if it is the root of the snapshot volume.
+   // "None" of the Windows API can deal with this kind of path without the trailing '\'
+   if (strncmp(ff->snap_top_fname, "//?/GLOBALROOT/Device/HarddiskVolumeShadowCopy", 46) == 0) {
+      q=&ff->snap_top_fname[46];
+      while (*q!='\0' && isdigit(*q)) q++;
+      if ((*q=='\0' || (*q=='/' && q[1]=='\0')) && ff->statp.st_rdev==WIN32_REPARSE_NONE) {
+         ff->root_of_volume = true;
+      }
+      if (*q=='\0') {
+         pm_strcat(ff->snap_top_fname, "/"); // of course this is posix, then use '/'
+      }
+   }
+
+   // ff->volume_path && ff->snapshot_path are just pointer without any allocated
+   // space, then they must point to some other pointer, snapshot::convert_path()
+   // does the same
+   ff->volume_path = ff->top_fname;    /* c:\tmp */
+   ff->top_fname_save = ff->top_fname;
+
+   ff->snapshot_path = ff->snap_top_fname;
+
+   ff->top_fname = ff->snap_top_fname;
+
+   Dmsg2(20, "ASX SnapConPath top_fname=%s snapshot_path=%s\n", ff->top_fname, ff->snapshot_path);
+
+   return true;
+}
+#else
 bool snapshot_convert_path(JCR *jcr, FF_PKT *ff, dlist *filelist, dlistString *node)
 {
    Dmsg1(DT_SNAPSHOT, "snapshot_convert_path(%s)\n", ff->top_fname);
    snapshot_manager *snapmgr = jcr->snap_mgr;
-   ff->strip_snap_path = false;
 
    if (!snapmgr) {
       return true;
@@ -1798,9 +1893,6 @@ bool snapshot_convert_path(JCR *jcr, FF_PKT *ff, dlist *filelist, dlistString *n
       return true;              /* not found */
    }
 
-   if (!ff->snap_fname) {
-      ff->snap_fname = get_pool_memory(PM_FNAME);
-   }
 
    /* Convert the filename to the original path */
    if (!elt->snap->convert_path(ff)) {
@@ -1810,6 +1902,7 @@ bool snapshot_convert_path(JCR *jcr, FF_PKT *ff, dlist *filelist, dlistString *n
    }
    return true;
 }
+#endif
 
 /* ListSnap[] = "CatReq Job=%s list_snapshot name=%s volume=%s device=%s tdate=%d type=%s before=%s after=%s expired=%d"; */