reftable/blocksource: stop using `xmmap()`
We use `xmmap()` to map reftables into memory. This function has two problems: - It causes us to die in case the mmap fails. - It ties us to the Git codebase. Refactor the code to use mmap(3p) instead with manual error checking. Note that this function may not be the system-provided mmap(3p), but may point to our `git_mmap()` wrapper that emulates the syscall on systems that do not have mmap(3p) available. Fix `reftable_block_source_from_file()` to properly bubble up the error code in case the map(3p) call fails. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt committed
Feb 18, 2025 at 10:20 UTC
70afa6fa318db517adb0cc7d4cb66260061bb684
1 file changed
+8
-3
reftable/blocksource.c
+8
-3
@@ -98,7 +98,7 @@ static struct reftable_block_source_vtable file_vtable = {
98
int reftable_block_source_from_file(struct reftable_block_source *bs,
99
const char *name)
100
{
101
- struct file_block_source *p;
101
+ struct file_block_source *p = NULL;
102
struct stat st;
103
int fd, err;
104
@@ -122,7 +122,12 @@ int reftable_block_source_from_file(struct reftable_block_source *bs,
122
}
123
124
p->size = st.st_size;
125
- p->data = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
125
+ p->data = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
126
+ if (p->data == MAP_FAILED) {
127
+ err = REFTABLE_IO_ERROR;
128
+ p->data = NULL;
129
+ goto out;
130
+ }
131
132
assert(!bs->ops);
133
bs->ops = &file_vtable;
@@ -135,5 +140,5 @@ out:
140
close(fd);
141
if (err < 0)
142
reftable_free(p);
138
- return 0;
143
+ return err;
144
}