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added a hook to reopen all tdb's after the server fork

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this prevents the fd seek pointer problem
This commit is contained in:
Andrew Tridgell 0001-01-01 00:00:00 +00:00
parent c4d8ad2c2e
commit f49518e497
3 changed files with 52 additions and 10 deletions
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3
source/smbd/server.c
View File

@ -309,6 +309,9 @@ max can be %d\n",
done correctly in the process. */
reset_globals_after_fork();
/* tdb needs special fork handling */
tdb_reopen_all();
return True;
}
/* The parent doesn't need this socket */

58
source/tdb/tdb.c
View File

@ -611,31 +611,24 @@ static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
#else
char b = 0;
#ifdef HAVE_PWRITE
if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) {
#else
if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 ||
write(tdb->fd, &b, 1) != 1) {
#endif
TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n",
size+addition, strerror(errno)));
return -1;
}
#endif
/* now fill the file with something. This ensures that the file isn't sparse, which would be
very bad if we ran out of disk. This must be done with write, not via mmap */
/* now fill the file with something. This ensures that the
file isn't sparse, which would be very bad if we ran out of
disk. This must be done with write, not via mmap */
memset(buf, 0x42, sizeof(buf));
while (addition) {
int n = addition>sizeof(buf)?sizeof(buf):addition;
#ifdef HAVE_PWRITE
int ret = pwrite(tdb->fd, buf, n, size);
#else
int ret;
if (lseek(tdb->fd, size, SEEK_SET) != size)
return -1;
ret = write(tdb->fd, buf, n);
#endif
if (ret != n) {
TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n",
n, strerror(errno)));
@ -1369,6 +1362,7 @@ TDB_CONTEXT *tdb_open(char *name, int hash_size, int tdb_flags,
tdb.map_ptr = NULL;
tdb.lockedkeys = NULL;
tdb.flags = tdb_flags;
tdb.open_flags = open_flags;
if ((open_flags & O_ACCMODE) == O_WRONLY)
goto fail;
@ -1605,3 +1599,47 @@ void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , cons
{
tdb->log_fn = fn;
}
/* reopen a tdb - this is used after a fork to ensure that we have an independent
seek pointer from our parent and to re-establish locks */
int tdb_reopen(TDB_CONTEXT *tdb)
{
struct stat st;
tdb_munmap(tdb);
close(tdb->fd);
tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
if (tdb->fd == -1) {
TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
goto fail;
}
fstat(tdb->fd, &st);
if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
goto fail;
}
tdb_mmap(tdb);
if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) {
TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
goto fail;
}
return 0;
fail:
tdb_close(tdb);
return -1;
}
/* reopen all tdb's */
int tdb_reopen_all(void)
{
TDB_CONTEXT *tdb;
for (tdb=tdbs; tdb; tdb = tdb->next) {
if (tdb_reopen(tdb) != 0) return -1;
}
return 0;
}

1
source/tdb/tdb.h
View File

@ -95,6 +95,7 @@ typedef struct tdb_context {
dev_t device; /* uniquely identifies this tdb */
ino_t inode; /* uniquely identifies this tdb */
void (*log_fn)(struct tdb_context *tdb, int level, const char *, ...); /* logging function */
int open_flags; /* flags used in the open - needed by reopen */
} TDB_CONTEXT;
typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *);