[pbs-devel] [PATCH proxmox-backup] tape: improve error on decode element status page
Dominik Csapak
d.csapak at proxmox.com
Wed Dec 6 09:17:54 CET 2023
instead of wrapping the function body in a 'try_block', simply move the
map_err to the only call site, where we can even add more context than
in the function itself.
aside from better error output, no functional change intended
this could help in debugging cases like this issue reported in the forum:
https://forum.proxmox.com/threads/137391/
Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
since most of this is just removing a level of indentation, best viewed with '-w'
pbs-tape/src/sg_pt_changer.rs | 227 +++++++++++++++++-----------------
1 file changed, 113 insertions(+), 114 deletions(-)
diff --git a/pbs-tape/src/sg_pt_changer.rs b/pbs-tape/src/sg_pt_changer.rs
index 6cb3a044..4c7b666e 100644
--- a/pbs-tape/src/sg_pt_changer.rs
+++ b/pbs-tape/src/sg_pt_changer.rs
@@ -326,7 +326,9 @@ fn get_element<F: AsRawFd>(
let data = execute_scsi_command(sg_raw, &cmd, "read element status (B8h)", retry)?;
- let page = decode_element_status_page(&data, start_element_address)?;
+ let page = decode_element_status_page(&data, start_element_address).map_err(|err| {
+ format_err!("decode element status for {element_type:?} on {start_element_address} failed - {err}")
+ })?;
retry = false; // only retry the first command
@@ -679,149 +681,146 @@ fn decode_element_status_page(
data: &[u8],
start_element_address: u16,
) -> Result<DecodedStatusPage, Error> {
- proxmox_lang::try_block!({
- let mut result = DecodedStatusPage {
- last_element_address: None,
- transports: Vec::new(),
- drives: Vec::new(),
- storage_slots: Vec::new(),
- import_export_slots: Vec::new(),
- };
+ let mut result = DecodedStatusPage {
+ last_element_address: None,
+ transports: Vec::new(),
+ drives: Vec::new(),
+ storage_slots: Vec::new(),
+ import_export_slots: Vec::new(),
+ };
- let mut reader = data;
+ let mut reader = data;
- let head: ElementStatusHeader = unsafe { reader.read_be_value()? };
+ let head: ElementStatusHeader = unsafe { reader.read_be_value()? };
- if head.number_of_elements_available == 0 {
- return Ok(result);
- }
+ if head.number_of_elements_available == 0 {
+ return Ok(result);
+ }
- if head.first_element_address_reported < start_element_address {
- bail!("got wrong first_element_address_reported"); // sanity check
+ if head.first_element_address_reported < start_element_address {
+ bail!("got wrong first_element_address_reported"); // sanity check
+ }
+
+ let len = head.byte_count_of_report_available;
+ let len = ((len[0] as usize) << 16) + ((len[1] as usize) << 8) + (len[2] as usize);
+
+ use std::cmp::Ordering;
+ match len.cmp(&reader.len()) {
+ Ordering::Less => reader = &reader[..len],
+ Ordering::Greater => bail!(
+ "wrong amount of data: expected {}, got {}",
+ len,
+ reader.len()
+ ),
+ _ => (),
+ }
+
+ loop {
+ if reader.is_empty() {
+ break;
}
- let len = head.byte_count_of_report_available;
- let len = ((len[0] as usize) << 16) + ((len[1] as usize) << 8) + (len[2] as usize);
-
- use std::cmp::Ordering;
- match len.cmp(&reader.len()) {
- Ordering::Less => reader = &reader[..len],
- Ordering::Greater => bail!(
- "wrong amount of data: expected {}, got {}",
- len,
- reader.len()
- ),
- _ => (),
+ let subhead: SubHeader = unsafe { reader.read_be_value()? };
+
+ let len = subhead.byte_count_of_descriptor_data_available;
+ let mut len = ((len[0] as usize) << 16) + ((len[1] as usize) << 8) + (len[2] as usize);
+ if len > reader.len() {
+ len = reader.len();
}
- loop {
- if reader.is_empty() {
- break;
- }
+ let descr_data = reader.read_exact_allocated(len)?;
- let subhead: SubHeader = unsafe { reader.read_be_value()? };
+ let descr_len = subhead.descriptor_length as usize;
- let len = subhead.byte_count_of_descriptor_data_available;
- let mut len = ((len[0] as usize) << 16) + ((len[1] as usize) << 8) + (len[2] as usize);
- if len > reader.len() {
- len = reader.len();
- }
+ if descr_len == 0 {
+ bail!("got elements, but descriptor length 0");
+ }
- let descr_data = reader.read_exact_allocated(len)?;
+ for descriptor in descr_data.chunks_exact(descr_len) {
+ let mut reader = descriptor;
- let descr_len = subhead.descriptor_length as usize;
+ match subhead.element_type_code {
+ 1 => {
+ let desc: TransportDescriptor = unsafe { reader.read_be_value()? };
- if descr_len == 0 {
- bail!("got elements, but descriptor length 0");
- }
+ let full = (desc.flags1 & 1) != 0;
+ let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
- for descriptor in descr_data.chunks_exact(descr_len) {
- let mut reader = descriptor;
+ subhead.skip_alternate_volume_tag(&mut reader)?;
- match subhead.element_type_code {
- 1 => {
- let desc: TransportDescriptor = unsafe { reader.read_be_value()? };
+ result.last_element_address = Some(desc.element_address);
+
+ let status = TransportElementStatus {
+ status: create_element_status(full, volume_tag),
+ element_address: desc.element_address,
+ };
+ result.transports.push(status);
+ }
+ 2 | 3 => {
+ let desc: StorageDescriptor = unsafe { reader.read_be_value()? };
- let full = (desc.flags1 & 1) != 0;
- let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
+ let full = (desc.flags1 & 1) != 0;
+ let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
- subhead.skip_alternate_volume_tag(&mut reader)?;
+ subhead.skip_alternate_volume_tag(&mut reader)?;
- result.last_element_address = Some(desc.element_address);
+ result.last_element_address = Some(desc.element_address);
- let status = TransportElementStatus {
+ if subhead.element_type_code == 3 {
+ let status = StorageElementStatus {
+ import_export: true,
status: create_element_status(full, volume_tag),
element_address: desc.element_address,
};
- result.transports.push(status);
- }
- 2 | 3 => {
- let desc: StorageDescriptor = unsafe { reader.read_be_value()? };
-
- let full = (desc.flags1 & 1) != 0;
- let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
-
- subhead.skip_alternate_volume_tag(&mut reader)?;
-
- result.last_element_address = Some(desc.element_address);
-
- if subhead.element_type_code == 3 {
- let status = StorageElementStatus {
- import_export: true,
- status: create_element_status(full, volume_tag),
- element_address: desc.element_address,
- };
- result.import_export_slots.push(status);
- } else {
- let status = StorageElementStatus {
- import_export: false,
- status: create_element_status(full, volume_tag),
- element_address: desc.element_address,
- };
- result.storage_slots.push(status);
- }
- }
- 4 => {
- let desc: TransferDescriptor = unsafe { reader.read_be_value()? };
-
- let loaded_slot = if (desc.flags2 & 128) != 0 {
- // SValid
- Some(desc.source_storage_element_address as u64)
- } else {
- None
- };
-
- let full = (desc.flags1 & 1) != 0;
- let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
-
- subhead.skip_alternate_volume_tag(&mut reader)?;
-
- let dvcid = decode_dvcid_info(&mut reader).unwrap_or(DvcidInfo {
- vendor: None,
- model: None,
- serial: None,
- });
-
- result.last_element_address = Some(desc.element_address);
-
- let drive = DriveStatus {
- loaded_slot,
+ result.import_export_slots.push(status);
+ } else {
+ let status = StorageElementStatus {
+ import_export: false,
status: create_element_status(full, volume_tag),
- drive_serial_number: dvcid.serial,
- vendor: dvcid.vendor,
- model: dvcid.model,
element_address: desc.element_address,
};
- result.drives.push(drive);
+ result.storage_slots.push(status);
}
- code => bail!("got unknown element type code {}", code),
}
+ 4 => {
+ let desc: TransferDescriptor = unsafe { reader.read_be_value()? };
+
+ let loaded_slot = if (desc.flags2 & 128) != 0 {
+ // SValid
+ Some(desc.source_storage_element_address as u64)
+ } else {
+ None
+ };
+
+ let full = (desc.flags1 & 1) != 0;
+ let volume_tag = subhead.parse_optional_volume_tag(&mut reader, full)?;
+
+ subhead.skip_alternate_volume_tag(&mut reader)?;
+
+ let dvcid = decode_dvcid_info(&mut reader).unwrap_or(DvcidInfo {
+ vendor: None,
+ model: None,
+ serial: None,
+ });
+
+ result.last_element_address = Some(desc.element_address);
+
+ let drive = DriveStatus {
+ loaded_slot,
+ status: create_element_status(full, volume_tag),
+ drive_serial_number: dvcid.serial,
+ vendor: dvcid.vendor,
+ model: dvcid.model,
+ element_address: desc.element_address,
+ };
+ result.drives.push(drive);
+ }
+ code => bail!("got unknown element type code {}", code),
}
}
+ }
- Ok(result)
- })
- .map_err(|err: Error| format_err!("decode element status failed - {}", err))
+ Ok(result)
}
/// Open the device for read/write, returns the file handle
--
2.39.2
More information about the pbs-devel
mailing list