pxar/extract: if possible create files sparesly

instead of filling them with zeroes

this fixes an issue where we could not restore a container with large
sparse files in the backup (e.g. a 10GiB sparse file in a container
with a 8GiB disk)

if the last operation of the copy was a seek, we need to truncate
the file to the correct size (seek beyond filesize does not change it)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
This commit is contained in:
Dominik Csapak 2021-02-17 14:13:22 +01:00 committed by Wolfgang Bumiller
parent e68c0e68bd
commit cba167b874

View File

@ -21,7 +21,10 @@ use pxar::Metadata;
use pxar::accessor::aio::{Accessor, FileContents, FileEntry};
use proxmox::c_result;
use proxmox::tools::fs::{create_path, CreateOptions};
use proxmox::tools::{
fs::{create_path, CreateOptions},
io::{sparse_copy, sparse_copy_async},
};
use crate::pxar::dir_stack::PxarDirStack;
use crate::pxar::metadata;
@ -411,10 +414,23 @@ impl Extractor {
)
.map_err(|err| format_err!("failed to apply initial flags: {}", err))?;
let extracted = io::copy(&mut *contents, &mut file)
let result = sparse_copy(&mut *contents, &mut file)
.map_err(|err| format_err!("failed to copy file contents: {}", err))?;
if size != extracted {
bail!("extracted {} bytes of a file of {} bytes", extracted, size);
if size != result.written {
bail!(
"extracted {} bytes of a file of {} bytes",
result.written,
size
);
}
if result.seeked_last {
while match nix::unistd::ftruncate(file.as_raw_fd(), size as i64) {
Ok(_) => false,
Err(nix::Error::Sys(errno)) if errno == nix::errno::Errno::EINTR => true,
Err(err) => bail!("error setting file size: {}", err),
} {}
}
metadata::apply(
@ -454,11 +470,24 @@ impl Extractor {
)
.map_err(|err| format_err!("failed to apply initial flags: {}", err))?;
let extracted = tokio::io::copy(&mut *contents, &mut file)
let result = sparse_copy_async(&mut *contents, &mut file)
.await
.map_err(|err| format_err!("failed to copy file contents: {}", err))?;
if size != extracted {
bail!("extracted {} bytes of a file of {} bytes", extracted, size);
if size != result.written {
bail!(
"extracted {} bytes of a file of {} bytes",
result.written,
size
);
}
if result.seeked_last {
while match nix::unistd::ftruncate(file.as_raw_fd(), size as i64) {
Ok(_) => false,
Err(nix::Error::Sys(errno)) if errno == nix::errno::Errno::EINTR => true,
Err(err) => bail!("error setting file size: {}", err),
} {}
}
metadata::apply(