[pbs-devel] [PATCH proxmox-backup v13 06/26] datastore: add helper for checking if a datastore is mounted
Hannes Laimer
h.laimer at proxmox.com
Wed Nov 13 16:00:42 CET 2024
... at a specific location. This is removable datastore specific so it
takes both a uuid and mount location.
Co-authored-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
---
changes since v12:
* clearify documentation
* make function more removable datastore specific to remove ambiguity
about what it does and what it is meant for
* only use for removable datastore
pbs-api-types/src/maintenance.rs | 2 +
pbs-datastore/src/datastore.rs | 73 +++++++++++++++++++++++++++++
pbs-datastore/src/lib.rs | 2 +-
src/server/metric_collection/mod.rs | 10 ++++
4 files changed, 86 insertions(+), 1 deletion(-)
diff --git a/pbs-api-types/src/maintenance.rs b/pbs-api-types/src/maintenance.rs
index fd4d3416..9f51292e 100644
--- a/pbs-api-types/src/maintenance.rs
+++ b/pbs-api-types/src/maintenance.rs
@@ -82,6 +82,8 @@ impl MaintenanceMode {
/// task finishes, so all open files are closed.
pub fn is_offline(&self) -> bool {
self.ty == MaintenanceType::Offline
+ || self.ty == MaintenanceType::Unmount
+ || self.ty == MaintenanceType::Delete
}
pub fn check(&self, operation: Option<Operation>) -> Result<(), Error> {
diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index fb37bd5a..cadf9245 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -1,5 +1,6 @@
use std::collections::{HashMap, HashSet};
use std::io::{self, Write};
+use std::os::unix::ffi::OsStrExt;
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::{Arc, LazyLock, Mutex};
@@ -14,6 +15,7 @@ use proxmox_schema::ApiType;
use proxmox_sys::error::SysError;
use proxmox_sys::fs::{file_read_optional_string, replace_file, CreateOptions};
use proxmox_sys::fs::{lock_dir_noblock, DirLockGuard};
+use proxmox_sys::linux::procfs::MountInfo;
use proxmox_sys::process_locker::ProcessLockSharedGuard;
use proxmox_worker_task::WorkerTaskContext;
@@ -46,6 +48,55 @@ pub fn check_backup_owner(owner: &Authid, auth_id: &Authid) -> Result<(), Error>
Ok(())
}
+/// Check if a device with a given UUID is currently mounted at store_mount_point by
+/// comparing the `st_rdev` values of `/dev/disk/by-uuid/<uuid>` and the source device in
+/// /proc/self/mountinfo.
+///
+/// If we can't check if it is mounted, we treat that as not mounted,
+/// returning false.
+///
+/// Reasons it could fail other than not being mounted where expected:
+/// - could not read /proc/self/mountinfo
+/// - could not stat /dev/disk/by-uuid/<uuid>
+/// - /dev/disk/by-uuid/<uuid> is not a block device
+///
+/// Since these are very much out of our control, there is no real value in distinguishing
+/// between them, so for this function they all are treated as 'device not mounted'
+pub fn is_datastore_mounted_at(store_mount_point: String, device_uuid: String) -> bool {
+ use nix::sys::stat::SFlag;
+
+ let store_mount_point = Path::new(&store_mount_point);
+
+ let dev_node = match nix::sys::stat::stat(format!("/dev/disk/by-uuid/{device_uuid}").as_str()) {
+ Ok(stat) if SFlag::from_bits_truncate(stat.st_mode) == SFlag::S_IFBLK => stat.st_rdev,
+ _ => return false,
+ };
+
+ let Ok(mount_info) = MountInfo::read() else {
+ return false;
+ };
+
+ for (_, entry) in mount_info {
+ let Some(source) = entry.mount_source else {
+ continue;
+ };
+
+ if entry.mount_point != store_mount_point || !source.as_bytes().starts_with(b"/") {
+ continue;
+ }
+
+ if let Ok(stat) = nix::sys::stat::stat(source.as_os_str()) {
+ let sflag = SFlag::from_bits_truncate(stat.st_mode);
+
+ if sflag == SFlag::S_IFBLK && stat.st_rdev == dev_node {
+ return true;
+ }
+ }
+ }
+
+ false
+}
+
/// Datastore Management
///
/// A Datastore can store severals backups, and provides the
@@ -154,6 +205,18 @@ impl DataStore {
bail!("datastore '{name}' is in {error}");
}
}
+ let mount_status = config
+ .get_mount_point()
+ .zip(config.backing_device.as_ref())
+ .map(|(mount_point, device_uuid)| {
+ is_datastore_mounted_at(mount_point, device_uuid.to_string())
+ });
+
+ if mount_status == Some(false) {
+ let mut datastore_cache = DATASTORE_MAP.lock().unwrap();
+ datastore_cache.remove(&config.name);
+ bail!("Removable Datastore is not mounted");
+ }
let mut datastore_cache = DATASTORE_MAP.lock().unwrap();
let entry = datastore_cache.get(name);
@@ -258,6 +321,16 @@ impl DataStore {
) -> Result<Arc<Self>, Error> {
let name = config.name.clone();
+ let mount_status = config
+ .get_mount_point()
+ .zip(config.backing_device.as_ref())
+ .map(|(mount_point, device_uuid)| {
+ is_datastore_mounted_at(mount_point, device_uuid.to_string())
+ });
+ if mount_status == Some(false) {
+ bail!("Datastore is not available")
+ }
+
let tuning: DatastoreTuning = serde_json::from_value(
DatastoreTuning::API_SCHEMA
.parse_property_string(config.tuning.as_deref().unwrap_or(""))?,
diff --git a/pbs-datastore/src/lib.rs b/pbs-datastore/src/lib.rs
index 202b0955..34113261 100644
--- a/pbs-datastore/src/lib.rs
+++ b/pbs-datastore/src/lib.rs
@@ -204,7 +204,7 @@ pub use manifest::BackupManifest;
pub use store_progress::StoreProgress;
mod datastore;
-pub use datastore::{check_backup_owner, DataStore};
+pub use datastore::{check_backup_owner, is_datastore_mounted_at, DataStore};
mod hierarchy;
pub use hierarchy::{
diff --git a/src/server/metric_collection/mod.rs b/src/server/metric_collection/mod.rs
index b95dba20..edba512c 100644
--- a/src/server/metric_collection/mod.rs
+++ b/src/server/metric_collection/mod.rs
@@ -176,6 +176,16 @@ fn collect_disk_stats_sync() -> (DiskStat, Vec<DiskStat>) {
continue;
}
+ let mount_status = config
+ .get_mount_point()
+ .zip(config.backing_device.as_ref())
+ .map(|(mount_point, device_uuid)| {
+ pbs_datastore::is_datastore_mounted_at(mount_point, device_uuid.to_string())
+ });
+ if mount_status == Some(false) {
+ continue;
+ }
+
datastores.push(gather_disk_stats(
disk_manager.clone(),
Path::new(&config.absolute_path()),
--
2.39.5
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