Commit 14ca1603 authored by Hallvard Furuseth's avatar Hallvard Furuseth
Browse files

ITS#8209 MDB_CP_COMPACT: Handle empty or broken DB

Preserve DB flags (use metapage#1) when main DB is empty.
Fail if metapage root != actual root in output file.
parent 1d862350
...@@ -679,6 +679,7 @@ int mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd); ...@@ -679,6 +679,7 @@ int mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd);
* <li>#MDB_CP_COMPACT - Perform compaction while copying: omit free * <li>#MDB_CP_COMPACT - Perform compaction while copying: omit free
* pages and sequentially renumber all pages in output. This option * pages and sequentially renumber all pages in output. This option
* consumes more CPU and runs more slowly than the default. * consumes more CPU and runs more slowly than the default.
* Currently it fails if the environment has suffered a page leak.
* </ul> * </ul>
* @return A non-zero error value on failure and 0 on success. * @return A non-zero error value on failure and 0 on success.
*/ */
......
...@@ -9093,6 +9093,7 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd) ...@@ -9093,6 +9093,7 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
mdb_copy my = {0}; mdb_copy my = {0};
MDB_txn *txn = NULL; MDB_txn *txn = NULL;
pthread_t thr; pthread_t thr;
pgno_t root, new_root;
int rc = MDB_SUCCESS; int rc = MDB_SUCCESS;
#ifdef _WIN32 #ifdef _WIN32
...@@ -9154,10 +9155,12 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd) ...@@ -9154,10 +9155,12 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
*(MDB_meta *)METADATA(mp) = *mm; *(MDB_meta *)METADATA(mp) = *mm;
mm = (MDB_meta *)METADATA(mp); mm = (MDB_meta *)METADATA(mp);
/* Count the number of free pages, subtract from lastpg to find /* Set metapage 1 with current main DB */
* number of active pages root = new_root = txn->mt_dbs[MAIN_DBI].md_root;
*/ if (root != P_INVALID) {
{ /* Count free pages + freeDB pages. Subtract from last_pg
* to find the new last_pg, which also becomes the new root.
*/
MDB_ID freecount = 0; MDB_ID freecount = 0;
MDB_cursor mc; MDB_cursor mc;
MDB_val key, data; MDB_val key, data;
...@@ -9170,19 +9173,26 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd) ...@@ -9170,19 +9173,26 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
txn->mt_dbs[FREE_DBI].md_leaf_pages + txn->mt_dbs[FREE_DBI].md_leaf_pages +
txn->mt_dbs[FREE_DBI].md_overflow_pages; txn->mt_dbs[FREE_DBI].md_overflow_pages;
/* Set metapage 1 */ new_root = txn->mt_next_pgno - 1 - freecount;
mm->mm_last_pg = txn->mt_next_pgno - freecount - 1; mm->mm_last_pg = new_root;
mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI]; mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
if (mm->mm_last_pg > NUM_METAS-1) { mm->mm_dbs[MAIN_DBI].md_root = new_root;
mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg; } else {
mm->mm_txnid = 1; /* When the DB is empty, handle it specially to
} else { * fix any breakage like page leaks from ITS#8174.
mm->mm_dbs[MAIN_DBI].md_root = P_INVALID; */
} mm->mm_dbs[MAIN_DBI].md_flags = txn->mt_dbs[MAIN_DBI].md_flags;
}
if (root != P_INVALID || mm->mm_dbs[MAIN_DBI].md_flags) {
mm->mm_txnid = 1; /* use metapage 1 */
} }
my.mc_wlen[0] = env->me_psize * NUM_METAS; my.mc_wlen[0] = env->me_psize * NUM_METAS;
my.mc_txn = txn; my.mc_txn = txn;
rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0); rc = mdb_env_cwalk(&my, &root, 0);
if (rc == MDB_SUCCESS && root != new_root) {
rc = MDB_INCOMPATIBLE; /* page leak or corrupt DB */
}
finish: finish:
if (rc) if (rc)
......
...@@ -36,6 +36,7 @@ Write the library version number to the standard output, and exit. ...@@ -36,6 +36,7 @@ Write the library version number to the standard output, and exit.
Compact while copying. Only current data pages will be copied; freed Compact while copying. Only current data pages will be copied; freed
or unused pages will be omitted from the copy. This option will or unused pages will be omitted from the copy. This option will
slow down the backup process as it is more CPU-intensive. slow down the backup process as it is more CPU-intensive.
Currently it fails if the environment has suffered a page leak.
.TP .TP
.BR \-n .BR \-n
Open LDMB environment(s) which do not use subdirectories. Open LDMB environment(s) which do not use subdirectories.
......
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