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Diffstat (limited to 'tdb/tdb.c')
-rw-r--r--tdb/tdb.c56
1 files changed, 49 insertions, 7 deletions
diff --git a/tdb/tdb.c b/tdb/tdb.c
index e87ea3692e..4cc1e07024 100644
--- a/tdb/tdb.c
+++ b/tdb/tdb.c
@@ -45,7 +45,12 @@
#define STANDALONE
#define TDB_DEBUG
#define HAVE_MMAP 1
-
+/* this should prevent deadlocks loops on corrupt databases
+ * we've discovered. Most deadlocks happend by iterating over the
+ * list of entries with the same hash value. */
+#define LOOP_MAX 100000
+#define TDB_LOG(x) TDB_LOG_UDEV x
+#define TDB_LOG_UDEV(tdb, level, format, arg...) info(format, ##arg)
#ifdef STANDALONE
#if HAVE_CONFIG_H
@@ -66,6 +71,7 @@
#include "tdb.h"
#include "spinlock.h"
#include "../udev_lib.h"
+#include "../logging.h"
#else
#include "includes.h"
#endif
@@ -89,7 +95,9 @@
/* NB assumes there is a local variable called "tdb" that is the
* current context, also takes doubly-parenthesized print-style
* argument. */
+#ifndef TDB_LOG
#define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0)
+#endif
/* lock offsets */
#define GLOBAL_LOCK 0
@@ -268,7 +276,7 @@ static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
if (tdb->locked[list+1].count == 0) {
if (!tdb->read_only && tdb->header.rwlocks) {
if (tdb_spinlock(tdb, list, ltype)) {
- TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list ltype=%d\n",
+ TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n",
list, ltype));
return -1;
}
@@ -481,7 +489,7 @@ static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
if (rec->magic == TDB_MAGIC) {
/* this happens when a app is showdown while deleting a record - we should
not completely fail when this happens */
- TDB_LOG((tdb, 0,"rec_free_read non-free magic at offset=%d - fixing\n",
+ TDB_LOG((tdb, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n",
rec->magic, off));
rec->magic = TDB_FREE_MAGIC;
if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
@@ -617,8 +625,10 @@ int tdb_printfreelist(TDB_CONTEXT *tdb)
static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
{
tdb_off last_ptr, i;
+ int maxloop;
/* read in the freelist top */
+ maxloop = LOOP_MAX;
last_ptr = FREELIST_TOP;
while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
if (i == off) {
@@ -627,6 +637,12 @@ static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
}
/* Follow chain (next offset is at start of record) */
last_ptr = i;
+
+ maxloop--;
+ if (maxloop == 0) {
+ TDB_LOG((tdb, 0, "remove_from_freelist: maxloop reached; corrupt database!\n"));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
+ }
}
TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
@@ -853,6 +869,7 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
{
tdb_off rec_ptr, last_ptr, newrec_ptr;
struct list_struct newrec;
+ int maxloop;
if (tdb_lock(tdb, -1, F_WRLCK) == -1)
return 0;
@@ -868,6 +885,7 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
goto fail;
/* keep looking until we find a freelist record big enough */
+ maxloop = LOOP_MAX;
while (rec_ptr) {
if (rec_free_read(tdb, rec_ptr, rec) == -1)
goto fail;
@@ -919,6 +937,12 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
/* move to the next record */
last_ptr = rec_ptr;
rec_ptr = rec->next;
+
+ maxloop--;
+ if (maxloop == 0) {
+ TDB_LOG((tdb, 0, "tdb_allocate: maxloop reached; corrupt database!\n"));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, 0);
+ }
}
/* we didn't find enough space. See if we can expand the
database and if we can then try again */
@@ -981,12 +1005,14 @@ static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
struct list_struct *r)
{
tdb_off rec_ptr;
-
+ int maxloop;
+
/* read in the hash top */
if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
+ maxloop = LOOP_MAX;
while (rec_ptr) {
if (rec_read(tdb, rec_ptr, r) == -1)
return 0;
@@ -1006,6 +1032,12 @@ static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
SAFE_FREE(k);
}
rec_ptr = r->next;
+
+ maxloop--;
+ if (maxloop == 0) {
+ TDB_LOG((tdb, 0, "tdb_find maxloop reached; corrupt database!\n"));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, 0);
+ }
}
return TDB_ERRCODE(TDB_ERR_NOEXIST, 0);
}
@@ -1188,6 +1220,7 @@ static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
{
tdb_off last_ptr, i;
struct list_struct lastrec;
+ int maxloop;
if (tdb->read_only) return -1;
@@ -1202,10 +1235,19 @@ static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
/* find previous record in hash chain */
if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
return -1;
- for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
+
+ maxloop = LOOP_MAX;
+ for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) {
if (rec_read(tdb, i, &lastrec) == -1)
return -1;
+ maxloop--;
+ if (maxloop == 0) {
+ TDB_LOG((tdb, 0, "(tdb)do_delete: maxloop reached; corrupt database!\n"));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
+ }
+ }
+
/* unlink it: next ptr is at start of record. */
if (last_ptr == 0)
last_ptr = TDB_HASH_TOP(rec->full_hash);
@@ -1789,8 +1831,8 @@ TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
/* Is it already in the open list? If so, fail. */
if (tdb_already_open(st.st_dev, st.st_ino)) {
TDB_LOG((tdb, 2, "tdb_open_ex: "
- "%s (%d,%d) is already open in this process\n",
- name, st.st_dev, st.st_ino));
+ "%s (%d:%d,%ld) is already open in this process\n",
+ name, major(st.st_dev), minor(st.st_dev), st.st_ino));
errno = EBUSY;
goto fail;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-20 14:30:25 +0000