tools: Finds missing files in gluster volume given backend brickpath

The tool finds the missing files in a geo-replication slave volume.
The tool crawls backend .glusterfs of the brickpath, which is passed
as a parameter and stats each entry on slave volume mount to check
the presence of file. The mount used is aux-gfid-mount, hence no path
conversion is required and is fast. The tool needs to be run on every
node in cluster for each brickpath of geo-rep master volume to find
missing files on slave volume. The tool is generic enough and can be
used in non geo-replication context as well.

Most of the crawler code is leverged from Avati's xfind and is modified
to crawl only .glusterfs (https://github.com/avati/xsync)

Thanks Aravinda for scripts to convert gfid to path.

Change-Id: I84deaaaf638f7c571ff1319b67a3440fe27da810
BUG: 1187140
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/9503
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/tools/gfind_missing_files/gfid_to_path.py b/tools/gfind_missing_files/gfid_to_path.py
new file mode 100644
index 00000000000..8362f68b955
--- /dev/null
+++ b/tools/gfind_missing_files/gfid_to_path.py
@@ -0,0 +1,162 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2015 Red Hat, Inc. <http://www.redhat.com/>
+# This file is part of GlusterFS.
+#
+# This file is licensed to you under your choice of the GNU Lesser
+# General Public License, version 3 or any later version (LGPLv3 or
+# later), or the GNU General Public License, version 2 (GPLv2), in all
+# cases as published by the Free Software Foundation.
+
+import sys
+import os
+import xattr
+import uuid
+import re
+import errno
+
+CHANGELOG_SEARCH_MAX_TRY = 31
+DEC_CTIME_START = 5
+ROOT_GFID = "00000000-0000-0000-0000-000000000001"
+MAX_NUM_CHANGELOGS_TRY = 2
+
+
+def output_not_found(gfid):
+    # Write GFID to stderr
+    sys.stderr.write("%s\n" % gfid)
+
+
+def output_success(path):
+    # Write converted Path to Stdout
+    sys.stdout.write("%s\n" % path)
+
+
+def full_dir_path(gfid):
+    out_path = ""
+    while True:
+        path = os.path.join(".glusterfs", gfid[0:2], gfid[2:4], gfid)
+        path_readlink = os.readlink(path)
+        pgfid = os.path.dirname(path_readlink)
+        out_path = os.path.join(os.path.basename(path_readlink), out_path)
+        if pgfid == "../../00/00/%s" % ROOT_GFID:
+            out_path = os.path.join("./", out_path)
+            break
+        gfid = os.path.basename(pgfid)
+    return out_path
+
+
+def find_path_from_changelog(fd, gfid):
+    """
+    In given Changelog File, finds using following pattern
+    <T><GFID>\x00<TYPE>\x00<MODE>\x00<UID>\x00<GID>\x00<PARGFID>/<BASENAME>
+    Pattern search finds PARGFID and BASENAME, Convert PARGFID to Path
+    Using readlink and add basename to form Full path.
+    """
+    content = fd.read()
+
+    pattern = "E%s" % gfid
+    pattern += "\x00(3|23)\x00\d+\x00\d+\x00\d+\x00([^\x00]+)/([^\x00]+)"
+    pat = re.compile(pattern)
+    match = pat.search(content)
+
+    if match:
+        pgfid = match.group(2)
+        basename = match.group(3)
+        if pgfid == ROOT_GFID:
+            return os.path.join("./", basename)
+        else:
+            full_path_parent = full_dir_path(pgfid)
+            if full_path_parent:
+                return os.path.join(full_path_parent, basename)
+
+    return None
+
+
+def gfid_to_path(gfid):
+    """
+    Try readlink, if it is directory it succeeds.
+    Get ctime of the GFID file, Decrement by 5 sec
+    Search for Changelog filename, Since Changelog file generated
+    every 15 sec, Search and get immediate next Changelog after the file
+    Creation. Get the Path by searching in Changelog file.
+    Get the resultant file's GFID and Compare with the input, If these
+    GFIDs are different then Some thing is changed(May be Rename)
+    """
+    gfid = gfid.strip()
+    gpath = os.path.join(".glusterfs", gfid[0:2], gfid[2:4], gfid)
+    try:
+        output_success(full_dir_path(gfid))
+        return
+    except OSError:
+        # Not an SymLink
+        pass
+
+    try:
+        ctime = int(os.stat(gpath).st_ctime)
+        ctime -= DEC_CTIME_START
+    except (OSError, IOError):
+        output_not_found(gfid)
+        return
+
+    path = None
+    found_changelog = False
+    changelog_parse_try = 0
+    for i in range(CHANGELOG_SEARCH_MAX_TRY):
+        cl = os.path.join(".glusterfs/changelogs", "CHANGELOG.%s" % ctime)
+
+        try:
+            with open(cl, "rb") as f:
+                changelog_parse_try += 1
+                found_changelog = True
+                path = find_path_from_changelog(f, gfid)
+                if not path and changelog_parse_try < MAX_NUM_CHANGELOGS_TRY:
+                    ctime += 1
+                    continue
+            break
+        except (IOError, OSError) as e:
+            if e.errno == errno.ENOENT:
+                ctime += 1
+            else:
+                break
+
+    if not found_changelog:
+        output_not_found(gfid)
+        return
+
+    if not path:
+        output_not_found(gfid)
+        return
+    gfid1 = str(uuid.UUID(bytes=xattr.get(path, "trusted.gfid")))
+    if gfid != gfid1:
+        output_not_found(gfid)
+        return
+
+    output_success(path)
+
+
+def main():
+    num_arguments = 3
+    if not sys.stdin.isatty():
+        num_arguments = 2
+
+    if len(sys.argv) != num_arguments:
+        sys.stderr.write("Invalid arguments\nUsage: "
+                         "%s <BRICK_PATH> <GFID_FILE>\n" % sys.argv[0])
+        sys.exit(1)
+
+    path = sys.argv[1]
+
+    if sys.stdin.isatty():
+        gfid_list = os.path.abspath(sys.argv[2])
+        os.chdir(path)
+        with open(gfid_list) as f:
+            for gfid in f:
+                gfid_to_path(gfid)
+    else:
+        os.chdir(path)
+        for gfid in sys.stdin:
+            gfid_to_path(gfid)
+
+
+if __name__ == "__main__":
+    main()