svn commit: r1712937 - /subversion/trunk/subversion/libsvn_fs_x/recovery.c

[st...@apache.org]

Author: stefan2
Date: Fri Nov  6 11:01:00 2015
New Revision: 1712937

URL: http://svn.apache.org/viewvc?rev=1712937&view=rev
Log:
In FSX, make 'svnadmin recover' discard all transactions - or any remnants
thereof.

Transactions are fragile wrt. to any scenario that would require a recovery
and dead txns tend to accumulate over time.  So, let's get rid of them
before somebody uses the FS API to reopen them and ends up with incomplete
or otherwise corrupted data.

This can be backported to FSFS.

* subversion/libsvn_fs_x/recovery.c
  (clear_directory,
   discard_transactions): New utilities implementing the txn cleanup.
  (recover_body): Invoke the new cleanup step.

Modified:
    subversion/trunk/subversion/libsvn_fs_x/recovery.c

Modified: subversion/trunk/subversion/libsvn_fs_x/recovery.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_x/recovery.c?rev=1712937&r1=1712936&r2=1712937&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_fs_x/recovery.c (original)
+++ subversion/trunk/subversion/libsvn_fs_x/recovery.c Fri Nov  6 11:01:00 2015
@@ -22,6 +22,7 @@
 
 #include "recovery.h"
 
+#include "svn_dirent_uri.h"
 #include "svn_hash.h"
 #include "svn_pools.h"
 #include "private/svn_string_private.h"
@@ -106,6 +107,72 @@ recover_get_largest_revision(svn_fs_t *f
   return SVN_NO_ERROR;
 }
 
+/* Delete all files and sub-directories (recursively) of DIR_PATH but
+   leave DIR_PATH itself in place.  Use SCRATCH_POOL for temporaries. */
+static svn_error_t *
+clear_directory(const char *dir_path,
+                apr_pool_t *scratch_pool)
+{
+  apr_hash_t *dirents;
+  apr_hash_index_t *hi;
+  apr_pool_t *iterpool = svn_pool_create(scratch_pool);
+
+  SVN_ERR(svn_io_get_dirents3(&dirents, dir_path, TRUE, scratch_pool,
+                              scratch_pool));
+
+  for (hi = apr_hash_first(scratch_pool, dirents);
+       hi;
+       hi = apr_hash_next(hi))
+    {
+      const char *path;
+      const char *name;
+      svn_dirent_t *dirent;
+
+      svn_pool_clear(iterpool);
+      apr_hash_this(hi, (const void **)&name, NULL, (void **)&dirent);
+
+      path = svn_dirent_join(dir_path, name, iterpool);
+      if (dirent->kind == svn_node_dir)
+        SVN_ERR(svn_io_remove_dir2(path, TRUE, NULL, NULL, iterpool));
+      else
+        SVN_ERR(svn_io_remove_file2(path, TRUE, iterpool));
+    }
+
+  svn_pool_destroy(iterpool);
+
+  return SVN_NO_ERROR;
+}
+
+/* Delete all uncommitted transaction data from FS.
+   Use SCRATCH_POOL for temporaries. */
+static svn_error_t *
+discard_transactions(svn_fs_t *fs,
+                     apr_pool_t *scratch_pool)
+{
+  svn_fs_x__data_t *ffd = fs->fsap_data;
+  svn_fs_x__shared_data_t *ffsd = ffd->shared;
+
+  /* In case this FS has been opened more than once in this process,
+     we should purge their shared transaction data as well.  We do the
+     same as abort_txn would, except that we don't expect all txn files
+     to be complete on disk. */
+  while (ffsd->txns)
+    {
+      svn_fs_x__shared_txn_data_t *txn = ffsd->txns;
+      ffsd->txns = txn->next;
+
+      svn_pool_destroy(txn->pool);
+    }
+
+  /* Remove anything from the transaction folders. */
+  SVN_ERR(clear_directory(svn_fs_x__path_txns_dir(fs, scratch_pool),
+                          scratch_pool));
+  SVN_ERR(clear_directory(svn_fs_x__path_txn_proto_revs(fs, scratch_pool),
+                          scratch_pool));
+
+  return SVN_NO_ERROR;
+}
+
 /* Baton used for recover_body below. */
 typedef struct recover_baton_t {
   svn_fs_t *fs;
@@ -136,6 +203,11 @@ recover_body(void *baton,
      Bump the instance ID. */
   SVN_ERR(svn_fs_x__set_uuid(fs, fs->uuid, NULL, TRUE, scratch_pool));
 
+  /* Because transactions are not resilient against system crashes,
+     any existing transaction is suspect (and would probably not be
+     reopened anyway).  Get rid of those. */
+  SVN_ERR(discard_transactions(fs, scratch_pool));
+
   /* We need to know the largest revision in the filesystem. */
   SVN_ERR(recover_get_largest_revision(fs, &max_rev, scratch_pool));