Unlike files accessed via a normal file system, the file->read_hook is
not honoured when using blocklist notation.
This means that when trying to use a dedicated, 1KiB, raw partition
for the environment block and hence does something like
save_env --file=(hd0,gpt9)0+2 X Y Z
this fails with "sparse file not allowed", which is rather unexpected,
as I've explicitly said exactly which blocks should be used. Adding a
little debugging reveals that grub_file_size (file) is 1024 as
expected, but total_length is 0, simply because the callback was never
invoked, so blocklists is an empty list.
Fix that by honouring the ->read_hook set by the caller, also when a
"file" is specified with blocklist notation.
Signed-off-by: Rasmus Villemoes <rasmus.villem...@prevas.dk>
---
I've tried to keep the patch at a minimum, but since the
disk->read_hook needs to be cleared on all return paths, it seemed a
little easier to drop the 'return -1' and instead set ret and break.
For readability, it seemed best to introduce the disk local variable to
hold file->device->disk, and then there's no point in not also using
that in the grub_disk_read() call.
grub-core/kern/fs.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/grub-core/kern/fs.c b/grub-core/kern/fs.c
index 7ad0aaf4e..79f1a797c 100644
--- a/grub-core/kern/fs.c
+++ b/grub-core/kern/fs.c
@@ -215,12 +215,15 @@ grub_fs_blocklist_read (grub_file_t file, char *buf,
grub_size_t len)
grub_disk_addr_t sector;
grub_off_t offset;
grub_ssize_t ret = 0;
+ grub_disk_t disk = file->device->disk;
if (len > file->size - file->offset)
len = file->size - file->offset;
sector = (file->offset >> GRUB_DISK_SECTOR_BITS);
offset = (file->offset & (GRUB_DISK_SECTOR_SIZE - 1));
+ disk->read_hook = file->read_hook;
+ disk->read_hook_data = file->read_hook_data;
for (p = file->data; p->length && len > 0; p++)
{
if (sector < p->length)
@@ -232,9 +235,12 @@ grub_fs_blocklist_read (grub_file_t file, char *buf,
grub_size_t len)
>> GRUB_DISK_SECTOR_BITS) > p->length - sector)
size = ((p->length - sector) << GRUB_DISK_SECTOR_BITS) - offset;
- if (grub_disk_read (file->device->disk, p->offset + sector, offset,
+ if (grub_disk_read (disk, p->offset + sector, offset,
size, buf) != GRUB_ERR_NONE)
- return -1;
+ {
+ ret = -1;
+ break;
+ }
ret += size;
len -= size;
@@ -244,6 +250,7 @@ grub_fs_blocklist_read (grub_file_t file, char *buf,
grub_size_t len)
else
sector -= p->length;
}
+ disk->read_hook = 0;
return ret;
}
--
2.46.0
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