When undoing an expansion of an mmap'd database while cancelling a
transaction, the tdb code prematurely decreases the variable that
tracks the file size, which leads to a region leak during the
subsequent unmap. Fix this by maintaining a separate counter for the
region size.
(This is probably unnecessary since e2undo was the only user of tdb
transactions, but I suppose we could be proactive.)
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
lib/ext2fs/tdb.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/ext2fs/tdb.c b/lib/ext2fs/tdb.c
index 61e30ed..1d97685 100644
--- a/lib/ext2fs/tdb.c
+++ b/lib/ext2fs/tdb.c
@@ -246,6 +246,7 @@ struct tdb_context {
int page_size;
int max_dead_records;
bool have_transaction_lock;
+ tdb_len_t real_map_size; /* how much space has been mapped */
};
@@ -970,9 +971,10 @@ int tdb_munmap(struct tdb_context *tdb)
#ifdef HAVE_MMAP
if (tdb->map_ptr) {
- int ret = munmap(tdb->map_ptr, tdb->map_size);
+ int ret = munmap(tdb->map_ptr, tdb->real_map_size);
if (ret != 0)
return ret;
+ tdb->real_map_size = 0;
}
#endif
tdb->map_ptr = NULL;
@@ -995,10 +997,12 @@ void tdb_mmap(struct tdb_context *tdb)
*/
if (tdb->map_ptr == MAP_FAILED) {
+ tdb->real_map_size = 0;
tdb->map_ptr = NULL;
TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %d (%s)\n",
tdb->map_size, strerror(errno)));
}
+ tdb->real_map_size = tdb->map_size;
} else {
tdb->map_ptr = NULL;
}
--
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