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Overview
Comment: | Remove some assert() statements that can fail with corrupt databases. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
7654ae71bd26ae5d713935624d2b6cb8 |
User & Date: | dan 2012-01-12 14:25:55.908 |
Context
2012-01-12
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15:05 | Fix typos in a testcase() macro introduced by the previous commit. (check-in: 0467742fd6 user: dan tags: trunk) | |
14:25 | Remove some assert() statements that can fail with corrupt databases. (check-in: 7654ae71bd user: dan tags: trunk) | |
2012-01-11
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16:16 | Remove code made unreachable by the enhancement of the previous check-in. (check-in: 9e31a275ef user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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4190 4191 4192 4193 4194 4195 4196 | pCur->validNKey = 0; if( pNewPage->nCell<1 || pNewPage->intKey!=pCur->apPage[i]->intKey ){ return SQLITE_CORRUPT_BKPT; } return SQLITE_OK; } | | | 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 | pCur->validNKey = 0; if( pNewPage->nCell<1 || pNewPage->intKey!=pCur->apPage[i]->intKey ){ return SQLITE_CORRUPT_BKPT; } return SQLITE_OK; } #if 0 /* ** Page pParent is an internal (non-leaf) tree page. This function ** asserts that page number iChild is the left-child if the iIdx'th ** cell in page pParent. Or, if iIdx is equal to the total number of ** cells in pParent, that page number iChild is the right-child of ** the page. */ |
︙ | ︙ | |||
4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 | ** the largest cell index. */ static void moveToParent(BtCursor *pCur){ assert( cursorHoldsMutex(pCur) ); assert( pCur->eState==CURSOR_VALID ); assert( pCur->iPage>0 ); assert( pCur->apPage[pCur->iPage] ); assertParentIndex( pCur->apPage[pCur->iPage-1], pCur->aiIdx[pCur->iPage-1], pCur->apPage[pCur->iPage]->pgno ); releasePage(pCur->apPage[pCur->iPage]); pCur->iPage--; pCur->info.nSize = 0; pCur->validNKey = 0; } /* | > > > > > > > > > > | 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 | ** the largest cell index. */ static void moveToParent(BtCursor *pCur){ assert( cursorHoldsMutex(pCur) ); assert( pCur->eState==CURSOR_VALID ); assert( pCur->iPage>0 ); assert( pCur->apPage[pCur->iPage] ); /* UPDATE: It is actually possible for the condition tested by the assert ** below to be untrue if the database file is corrupt. This can occur if ** one cursor has modified page pParent while a reference to it is held ** by a second cursor. Which can only happen if a single page is linked ** into more than one b-tree structure in a corrupt database. */ #if 0 assertParentIndex( pCur->apPage[pCur->iPage-1], pCur->aiIdx[pCur->iPage-1], pCur->apPage[pCur->iPage]->pgno ); #endif testcase( iIdx>pParent->nCell ); releasePage(pCur->apPage[pCur->iPage]); pCur->iPage--; pCur->info.nSize = 0; pCur->validNKey = 0; } /* |
︙ | ︙ | |||
4697 4698 4699 4700 4701 4702 4703 | return SQLITE_OK; } pCur->skipNext = 0; pPage = pCur->apPage[pCur->iPage]; idx = ++pCur->aiIdx[pCur->iPage]; assert( pPage->isInit ); | > > > > > > | | 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 | return SQLITE_OK; } pCur->skipNext = 0; pPage = pCur->apPage[pCur->iPage]; idx = ++pCur->aiIdx[pCur->iPage]; assert( pPage->isInit ); /* If the database file is corrupt, it is possible for the value of idx ** to be invalid here. This can only occur if a second cursor modifies ** the page while cursor pCur is holding a reference to it. Which can ** only happen if the database is corrupt in such a way as to link the ** page into more than one b-tree structure. */ testcase( idx>pPage->nCell ); pCur->info.nSize = 0; pCur->validNKey = 0; if( idx>=pPage->nCell ){ if( !pPage->leaf ){ rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8])); if( rc ) return rc; |
︙ | ︙ |
Added test/corruptF.test.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | # 2012 January 12 # # 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. # #*********************************************************************** # set testdir [file dirname $argv0] source $testdir/tester.tcl set testprefix corruptF # Do not use a codec for tests in this file, as the database file is # manipulated directly using tcl scripts (using the [hexio_write] command). # do_not_use_codec proc str {i} { format %08d $i } # Create a 6 page database containing a single table - t1. Table t1 # consists of page 2 (the root page) and pages 5 and 6 (leaf pages). # Database pages 3 and 4 are on the free list. # proc create_test_db {} { catch { db close } forcedelete test.db sqlite3 db test.db db func str str execsql { PRAGMA auto_vacuum = 0; PRAGMA page_size = 1024; CREATE TABLE t1(x); /* root page = 2 */ CREATE TABLE t2(x); /* root page = 3 */ CREATE TABLE t3(x); /* root page = 4 */ INSERT INTO t1 VALUES(str(1)); INSERT INTO t1 SELECT str(rowid+1) FROM t1; INSERT INTO t1 SELECT str(rowid+2) FROM t1; INSERT INTO t1 SELECT str(rowid+4) FROM t1; INSERT INTO t1 SELECT str(rowid+8) FROM t1; INSERT INTO t1 SELECT str(rowid+16) FROM t1; INSERT INTO t1 SELECT str(rowid+32) FROM t1; INSERT INTO t1 SELECT str(rowid+64) FROM t1; DROP TABLE t2; DROP TABLE t3; } db close } do_test 1.1 { create_test_db } {} # Check the db is as we expect. 6 pages in total, with 3 and 4 on the free # list. Page 3 is the free list trunk and page 4 is a leaf. # do_test 1.2 { file size test.db } [expr 6*1024] do_test 1.3 { hexio_read test.db 32 4 } 00000003 do_test 1.4 { hexio_read test.db [expr 2*1024] 12 } 000000000000000100000004 # Change the free-list entry to page 6 and reopen the db file. do_test 1.5 { hexio_write test.db [expr 2*1024 + 8] 00000006 sqlite3 db test.db } {} # Now create a new table in the database file. The root of the new table # is page 6, which is also the right-most leaf page in table t1. # do_execsql_test 1.6 { CREATE TABLE t4(x); SELECT * FROM sqlite_master; } { table t1 t1 2 {CREATE TABLE t1(x)} table t4 t4 6 {CREATE TABLE t4(x)} } # At one point this was causing an assert to fail. # # This statement opens a cursor on table t1 and does a full table scan. As # each row is visited, it is copied into table t4. There is no temporary # table. # # When the t1 cursor reaches page 6 (which is both the right-most leaf of # t1 and the root of t4), it continues to iterate through the keys within # it (which at this point are keys that have been inserted into t4). And # for each row visited, another row is inserted into page 6 - it being the # root page of t4. Eventually, page 6 becomes full and the height of the # b-tree for table t4 increased. From the point of view of the t1 cursor, # this unexpectedly reduces the number of keys on page 6 in the middle of # its iteration, which causes an assert() to fail. # db_save_and_close if 1 { for {set i 0} {$i < 128} {incr i} { db_restore_and_reopen do_test 1.7.$i { set res [ catchsql { INSERT INTO t4 SELECT x FROM t1 WHERE rowid>$i } ] if {$res == "0 {}" || $res == "1 {database disk image is malformed}"} { set res "" } set res } {} } } do_test 2.1 { create_test_db } {} do_test 2.2 { file size test.db } [expr 6*1024] do_test 2.3 { hexio_read test.db 32 4 } 00000003 do_test 2.4 { hexio_read test.db [expr 2*1024] 12 } 000000000000000100000004 # Change the free-list entry to page 5 and reopen the db file. do_test 2.5 { hexio_write test.db [expr 2*1024 + 8] 00000005 sqlite3 db test.db } {} # Now create a new table in the database file. The root of the new table # is page 5, which is also the right-most leaf page in table t1. # do_execsql_test 2.6 { CREATE TABLE t4(x); SELECT * FROM sqlite_master; } { table t1 t1 2 {CREATE TABLE t1(x)} table t4 t4 5 {CREATE TABLE t4(x)} } db_save_and_close for {set i 127} {$i >= 0} {incr i -1} { db_restore_and_reopen do_test 2.7.$i { set res [ catchsql { INSERT INTO t4 SELECT x FROM t1 WHERE rowid<$i ORDER BY rowid DESC } ] if {$res == "0 {}" || $res == "1 {database disk image is malformed}"} { set res "" } set res } {} } finish_test |