Add tests to ensure that an sqlite3_snapshot_open() client cannot be tricked into reading a corrupt snapshot even if another process fails mid-checkpoint.

FossilOrigin-Name: b908048b6cfa1ee2fe1f7a17bae475ddd9d0376c
2015-12-10 18:06:21 +00:00
parent 3bf83ccd70
commit 7d15979420
4 changed files with 174 additions and 10 deletions
@@ -1,5 +1,5 @@
-C Have\ssqlite3_snapshot_open()\savoid\sa\srace\scondition\sby\staking\sa\sshared\sCHECKPOINTER\slock\swhile\schecking\spInfo->nBackfillAttempted.
-D 2015-12-10T15:45:15.186
+C Add\stests\sto\sensure\sthat\san\ssqlite3_snapshot_open()\sclient\scannot\sbe\stricked\sinto\sreading\sa\scorrupt\ssnapshot\seven\sif\sanother\sprocess\sfails\smid-checkpoint.
+D 2015-12-10T18:06:21.050
 F Makefile.in 28bcd6149e050dff35d4dcfd97e890cd387a499d
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc e8fdca1cb89a1b58b5f4d3a130ea9a3d28cb314d
@@ -1020,7 +1020,8 @@ F test/skipscan2.test d1d1450952b7275f0b0a3a981f0230532743951a
 F test/skipscan3.test ec5bab3f81c7038b43450e7b3062e04a198bdbb5
 F test/skipscan5.test 67817a4b6857c47e0e33ba3e506da6f23ef68de2
 F test/skipscan6.test 5866039d03a56f5bd0b3d172a012074a1d90a15b
-F test/snapshot.test f91d907460e7acc01d531834d068e1215ccac7e4
+F test/snapshot.test 5631669a133c96aaa228f7233989f6d2d069fb02
+F test/snapshot_fault.test 06472056c516be4610834de4688ea3357e8bde01
 F test/soak.test 0b5b6375c9f4110c828070b826b3b4b0bb65cd5f
 F test/softheap1.test 843cd84db9891b2d01b9ab64cef3e9020f98d087
 F test/sort.test 3f492e5b7be1d3f756728d2ff6edf4f6091e84cb
@@ -1409,7 +1410,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 3a18526fc2253658dad84c5e600481c8a62efe40
-R 7bb35c02cb12ea2ff304c777229238a5
+P 8084eae0bc4f6513b1147fb890a6b2813f1c0a09
+R b7a6ff87063d246e894cc3fd88f3e89f
 U dan
-Z 0b9f17bd41106b46c64f60d98c85b1e3
+Z 1fe7db1e51b0eef5aa529631bb7527d1
@@ -1 +1 @@
-8084eae0bc4f6513b1147fb890a6b2813f1c0a09
+b908048b6cfa1ee2fe1f7a17bae475ddd9d0376c
@@ -8,10 +8,9 @@
 #    May you share freely, never taking more than you give.
 #
 #***********************************************************************
-# This file implements regression tests for SQLite library.  The
-# focus of this file is testing the SELECT statement.
+# This file implements regression tests for SQLite library. The focus
+# of this file is the sqlite3_snapshot_xxx() APIs.
 #
-# $Id: select1.test,v 1.70 2009/05/28 01:00:56 drh Exp $

 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -0,0 +1,164 @@
+# 2015 December 10
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. The focus
+# of this file is the sqlite3_snapshot_xxx() APIs.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix snapshot_fault
+
+#-------------------------------------------------------------------------
+# Check that an sqlite3_snapshot_open() client cannot be tricked into
+# reading a corrupt snapshot even if a second client fails while 
+# checkpointing the db.
+#
+do_faultsim_test 1.0 -prep {
+  faultsim_delete_and_reopen
+  sqlite3 db2 test.db
+  db2 eval { 
+    CREATE TABLE t1(a, b UNIQUE, c UNIQUE);
+    INSERT INTO t1 VALUES(1, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(2, randomblob(500), randomblob(500));
+    PRAGMA journal_mode = wal;
+    INSERT INTO t1 VALUES(3, randomblob(500), randomblob(500));
+    BEGIN;
+      SELECT a FROM t1;
+  }
+  set ::snapshot [sqlite3_snapshot_get db2 main] 
+  db2 eval COMMIT
+  db2 eval {
+    UPDATE t1 SET b=randomblob(501), c=randomblob(501) WHERE a=1;
+    INSERT INTO t1 VALUES(4, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(5, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(6, randomblob(500), randomblob(500));
+  }
+} -body {
+  db eval { PRAGMA wal_checkpoint }
+} -test {
+  db2 eval BEGIN
+  if {[catch { sqlite3_snapshot_open db2 main $::snapshot } msg]} {
+    if {$msg != "SQLITE_BUSY_SNAPSHOT" && $msg != "SQLITE_BUSY"} {
+      error "error is $msg" 
+    }
+  } else {
+    set res [db2 eval { 
+      SELECT a FROM t1;
+      PRAGMA integrity_check;
+    }]
+    if {$res != "1 2 3 ok"} { error "res is $res" }
+  }
+
+  sqlite3_snapshot_free $::snapshot
+}
+
+#-------------------------------------------------------------------------
+# This test is similar to the previous one. Except, after the 
+# "PRAGMA wal_checkpoint" command fails the db is closed and reopened
+# so as to require wal file recovery. It should not be possible to open
+# a snapshot that is part of the body of a recovered wal file.
+#
+do_faultsim_test 2.0 -prep {
+  faultsim_delete_and_reopen
+  db eval { 
+    CREATE TABLE t1(a, b UNIQUE, c UNIQUE);
+    INSERT INTO t1 VALUES(1, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(2, randomblob(500), randomblob(500));
+    PRAGMA journal_mode = wal;
+    INSERT INTO t1 VALUES(3, randomblob(500), randomblob(500));
+    BEGIN;
+      SELECT a FROM t1;
+  }
+  set ::snapshot [sqlite3_snapshot_get db main] 
+  db eval COMMIT
+
+  db eval {
+    UPDATE t1 SET b=randomblob(501), c=randomblob(501) WHERE a=1;
+    INSERT INTO t1 VALUES(4, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(5, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(6, randomblob(500), randomblob(500));
+  }
+} -body {
+  db eval { PRAGMA wal_checkpoint }
+} -test {
+
+  db_save
+  db close
+  db_restore_and_reopen
+  db eval { SELECT * FROM t1 }
+  
+  db eval BEGIN
+  if {[catch { sqlite3_snapshot_open db main $::snapshot } msg]} {
+    if {$msg != "SQLITE_BUSY_SNAPSHOT" && $msg != "SQLITE_BUSY"} {
+      error "error is $msg" 
+    }
+  } else {
+    # This branch should actually never be taken. But it was useful in
+    # determining whether or not this test was actually working (by 
+    # running a modified version of SQLite that allowed snapshots to be
+    # opened following a recovery).
+    error "TEST HAS FAILED"
+
+    set res [db eval { 
+      SELECT a FROM t1;
+      PRAGMA integrity_check;
+    }]
+    if {$res != "1 2 3 ok"} { error "res is $res" }
+  }
+
+  sqlite3_snapshot_free $::snapshot
+}
+
+#-------------------------------------------------------------------------
+# Test the handling of faults that occur within sqlite3_snapshot_open().
+#
+do_faultsim_test 3.0 -prep {
+  faultsim_delete_and_reopen
+  db eval { 
+    CREATE TABLE t1(a, b UNIQUE, c UNIQUE);
+    INSERT INTO t1 VALUES(1, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(2, randomblob(500), randomblob(500));
+    PRAGMA journal_mode = wal;
+    INSERT INTO t1 VALUES(3, randomblob(500), randomblob(500));
+    BEGIN;
+      SELECT a FROM t1;
+  }
+  set ::snapshot [sqlite3_snapshot_get db main] 
+  db eval COMMIT
+  db eval {
+    UPDATE t1 SET b=randomblob(501), c=randomblob(501) WHERE a=1;
+    INSERT INTO t1 VALUES(4, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(5, randomblob(500), randomblob(500));
+    INSERT INTO t1 VALUES(6, randomblob(500), randomblob(500));
+    BEGIN;
+  }
+} -body {
+  if { [catch { sqlite3_snapshot_open db main $::snapshot } msg] } {
+    error $msg
+  }
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_IOERR} \
+                              {1 SQLITE_IOERR_NOMEM} {1 SQLITE_IOERR_READ}
+  if {$testrc==0} {
+    set res [db eval { 
+      SELECT a FROM t1;
+      PRAGMA integrity_check;
+    }]
+    if {$res != "1 2 3 ok"} { error "res is $res" }
+  }
+
+  sqlite3_snapshot_free $::snapshot
+}
+
+
+
+finish_test
+