diff options
Diffstat (limited to 'devices/src/virtio/block.rs')
| -rw-r--r-- | devices/src/virtio/block.rs | 111 |
1 files changed, 74 insertions, 37 deletions
diff --git a/devices/src/virtio/block.rs b/devices/src/virtio/block.rs index 73fd416..b171864 100644 --- a/devices/src/virtio/block.rs +++ b/devices/src/virtio/block.rs @@ -3,7 +3,7 @@ // found in the LICENSE file. use std::fmt::{self, Display}; -use std::io::{self, Seek, SeekFrom}; +use std::io::{self, Seek, SeekFrom, Write}; use std::mem::size_of; use std::os::unix::io::{AsRawFd, RawFd}; use std::result; @@ -129,12 +129,14 @@ unsafe impl DataInit for virtio_blk_discard_write_zeroes {} #[derive(Debug)] enum ExecuteError { Descriptor(DescriptorError), + Read(io::Error), + WriteStatus(io::Error), /// Error arming the flush timer. Flush(io::Error), ReadIo { length: usize, sector: u64, - desc_error: DescriptorError, + desc_error: io::Error, }, ShortRead { sector: u64, @@ -149,7 +151,7 @@ enum ExecuteError { WriteIo { length: usize, sector: u64, - desc_error: DescriptorError, + desc_error: io::Error, }, ShortWrite { sector: u64, @@ -176,6 +178,8 @@ impl Display for ExecuteError { match self { Descriptor(e) => write!(f, "virtio descriptor error: {}", e), + Read(e) => write!(f, "failed to read message: {}", e), + WriteStatus(e) => write!(f, "failed to write request status: {}", e), Flush(e) => write!(f, "failed to flush: {}", e), ReadIo { length, @@ -247,6 +251,8 @@ impl ExecuteError { fn status(&self) -> u8 { match self { ExecuteError::Descriptor(_) => VIRTIO_BLK_S_IOERR, + ExecuteError::Read(_) => VIRTIO_BLK_S_IOERR, + ExecuteError::WriteStatus(_) => VIRTIO_BLK_S_IOERR, ExecuteError::Flush(_) => VIRTIO_BLK_S_IOERR, ExecuteError::ReadIo { .. } => VIRTIO_BLK_S_IOERR, ExecuteError::ShortRead { .. } => VIRTIO_BLK_S_IOERR, @@ -275,6 +281,50 @@ struct Worker { } impl Worker { + fn process_one_request( + avail_desc: DescriptorChain, + read_only: bool, + disk: &mut DiskFile, + disk_size: u64, + flush_timer: &mut TimerFd, + flush_timer_armed: &mut bool, + mem: &GuestMemory, + ) -> result::Result<usize, ExecuteError> { + let mut status_writer = + Writer::new(mem, avail_desc.clone()).map_err(ExecuteError::Descriptor)?; + let available_bytes = status_writer + .available_bytes() + .map_err(ExecuteError::Descriptor)?; + let status_offset = available_bytes + .checked_sub(1) + .ok_or(ExecuteError::MissingStatus)?; + + status_writer = status_writer + .split_at(status_offset) + .map_err(ExecuteError::Descriptor)?; + + let status = match Block::execute_request( + avail_desc, + read_only, + disk, + disk_size, + flush_timer, + flush_timer_armed, + mem, + ) { + Ok(()) => VIRTIO_BLK_S_OK, + Err(e) => { + error!("failed executing disk request: {}", e); + e.status() + } + }; + + status_writer + .write_all(&[status]) + .map_err(ExecuteError::WriteStatus)?; + Ok(available_bytes) + } + fn process_queue( &mut self, queue_index: usize, @@ -288,9 +338,8 @@ impl Worker { let mut needs_interrupt = false; while let Some(avail_desc) = queue.pop(&self.mem) { let desc_index = avail_desc.index; - let mut status_writer = Writer::new(&self.mem, avail_desc.clone()); - let status = match Block::execute_request( + let len = match Worker::process_one_request( avail_desc, self.read_only, &mut *self.disk_image, @@ -299,24 +348,11 @@ impl Worker { flush_timer_armed, &self.mem, ) { - Ok(()) => VIRTIO_BLK_S_OK, + Ok(len) => len, Err(e) => { - error!("failed executing disk request: {}", e); - e.status() - } - }; - - let len = if let Ok(status_offset) = status_writer.seek(SeekFrom::End(-1)) { - match status_writer.write_all(&[status]) { - Ok(_) => status_offset + 1, - Err(e) => { - error!("failed to write status: {}", e); - 0 - } + error!("block: failed to handle request: {}", e); + 0 } - } else { - error!("failed to seek to status location"); - 0 }; queue.add_used(&self.mem, desc_index, len as u32); @@ -541,11 +577,10 @@ impl Block { flush_timer_armed: &mut bool, mem: &GuestMemory, ) -> result::Result<(), ExecuteError> { - let mut reader = Reader::new(mem, avail_desc.clone()); - let mut writer = Writer::new(mem, avail_desc); + let mut reader = Reader::new(mem, avail_desc.clone()).map_err(ExecuteError::Descriptor)?; + let mut writer = Writer::new(mem, avail_desc).map_err(ExecuteError::Descriptor)?; - let req_header: virtio_blk_req_header = - reader.read_obj().map_err(ExecuteError::Descriptor)?; + let req_header: virtio_blk_req_header = reader.read_obj().map_err(ExecuteError::Read)?; let req_type = req_header.req_type.to_native(); let sector = req_header.sector.to_native(); @@ -580,6 +615,7 @@ impl Block { // The last byte of writer is virtio_blk_req::status, so subtract it from data_len. let data_len = writer .available_bytes() + .map_err(ExecuteError::Descriptor)? .checked_sub(1) .ok_or(ExecuteError::MissingStatus)?; let offset = sector @@ -588,14 +624,13 @@ impl Block { check_range(offset, data_len as u64, disk_size)?; disk.seek(SeekFrom::Start(offset)) .map_err(|e| ExecuteError::Seek { ioerr: e, sector })?; - let actual_length = - writer - .write_from_volatile(disk, data_len) - .map_err(|desc_error| ExecuteError::ReadIo { - length: data_len, - sector, - desc_error, - })?; + let actual_length = writer.write_from(disk, data_len).map_err(|desc_error| { + ExecuteError::ReadIo { + length: data_len, + sector, + desc_error, + } + })?; if actual_length < data_len { return Err(ExecuteError::ShortRead { sector, @@ -605,7 +640,7 @@ impl Block { } } VIRTIO_BLK_T_OUT => { - let data_len = reader.available_bytes(); + let data_len = reader.available_bytes().map_err(ExecuteError::Descriptor)?; let offset = sector .checked_shl(u32::from(SECTOR_SHIFT)) .ok_or(ExecuteError::OutOfRange)?; @@ -614,7 +649,7 @@ impl Block { .map_err(|e| ExecuteError::Seek { ioerr: e, sector })?; let actual_length = reader - .read_to_volatile(disk, data_len) + .read_to(disk, data_len) .map_err(|desc_error| ExecuteError::WriteIo { length: data_len, sector, @@ -635,9 +670,11 @@ impl Block { } } VIRTIO_BLK_T_DISCARD | VIRTIO_BLK_T_WRITE_ZEROES => { - while reader.available_bytes() >= size_of::<virtio_blk_discard_write_zeroes>() { + while reader.available_bytes().map_err(ExecuteError::Descriptor)? + >= size_of::<virtio_blk_discard_write_zeroes>() + { let seg: virtio_blk_discard_write_zeroes = - reader.read_obj().map_err(ExecuteError::Descriptor)?; + reader.read_obj().map_err(ExecuteError::Read)?; let sector = seg.sector.to_native(); let num_sectors = seg.num_sectors.to_native(); |