feat(s3): enforce multipart presigned size limits (#6732)

crates/ecstore/src/error/mod.rs

@@ -157,6 +157,8 @@ pub enum StorageError {
     InvalidPartNumber(usize),
     #[error("Your proposed upload is smaller than the minimum allowed size. Part {0} size {1} is less than minimum {2}")]
     EntityTooSmall(usize, i64, i64),
+    #[error("multipart upload size {0} exceeds the configured limit {1}")]
+    EntityTooLarge(u64, u64),
 
     // ── Erasure / Quorum ─────────────────────────────────────────────
     #[error("erasure read quorum")]
@@ -554,6 +556,7 @@ impl Clone for StorageError {
             StorageError::DecommissionNotStarted => StorageError::DecommissionNotStarted,
             StorageError::InvalidPart(a, b, c) => StorageError::InvalidPart(*a, b.clone(), c.clone()),
             StorageError::EntityTooSmall(a, b, c) => StorageError::EntityTooSmall(*a, *b, *c),
+            StorageError::EntityTooLarge(a, b) => StorageError::EntityTooLarge(*a, *b),
             StorageError::DoneForNow => StorageError::DoneForNow,
             StorageError::DecommissionAlreadyRunning => StorageError::DecommissionAlreadyRunning,
             StorageError::RebalanceAlreadyRunning => StorageError::RebalanceAlreadyRunning,
@@ -673,6 +676,7 @@ impl StorageError {
             StorageError::InsufficientWriteQuorum(_, _) => StorageErrorCode::InsufficientWriteQuorum,
             StorageError::PreconditionFailed => StorageErrorCode::PreconditionFailed,
             StorageError::EntityTooSmall(_, _, _) => StorageErrorCode::EntityTooSmall,
+            StorageError::EntityTooLarge(_, _) => StorageErrorCode::EntityTooLarge,
             StorageError::InvalidRangeSpec(_) => StorageErrorCode::InvalidRangeSpec,
             StorageError::NotModified => StorageErrorCode::NotModified,
             StorageError::InvalidPartNumber(_) => StorageErrorCode::InvalidPartNumber,
@@ -795,6 +799,7 @@ impl StorageError {
             StorageErrorCode::EntityTooSmall => {
                 Some(StorageError::EntityTooSmall(Default::default(), Default::default(), Default::default()))
             }
+            StorageErrorCode::EntityTooLarge => Some(StorageError::EntityTooLarge(Default::default(), Default::default())),
             StorageErrorCode::InvalidRangeSpec => Some(StorageError::InvalidRangeSpec(Default::default())),
             StorageErrorCode::NotModified => Some(StorageError::NotModified),
             StorageErrorCode::InvalidPartNumber => Some(StorageError::InvalidPartNumber(Default::default())),

crates/ecstore/src/set_disk/ops/multipart.rs

@@ -84,11 +84,13 @@ use rustfs_rio::TryGetIndex;
 use rustfs_utils::http::SSEC_ALGORITHM_HEADER;
 #[cfg(test)]
 use rustfs_utils::http::SUFFIX_COMPRESSION;
+use rustfs_utils::http::{SUFFIX_MAX_TOTAL_OBJECT_SIZE, get_consistent_str};
 use std::future::Future;
 #[cfg(test)]
 use std::sync::atomic::AtomicBool;
 #[cfg(any(test, feature = "test-util"))]
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Mutex, OnceLock};
 #[cfg(any(test, feature = "test-util"))]
 use std::time::Duration;
 #[cfg(test)]
@@ -97,6 +99,83 @@ use tokio::task::JoinSet;
 
 const MULTIPART_LIST_IO_CONCURRENCY: usize = 16;
 
+static CAPPED_MULTIPART_STAGING: OnceLock<Mutex<HashMap<String, Arc<tokio::sync::Semaphore>>>> = OnceLock::new();
+
+struct CappedMultipartStagingGuard {
+    upload_id_path: String,
+    permit: Option<tokio::sync::OwnedSemaphorePermit>,
+}
+
+impl Drop for CappedMultipartStagingGuard {
+    fn drop(&mut self) {
+        // Release the permit before checking the Arc count so a concurrent
+        // Abort/Complete cleanup can remove the now-unused map entry.
+        self.permit.take();
+        remove_capped_multipart_staging_semaphore(&self.upload_id_path);
+    }
+}
+
+fn capped_multipart_staging_semaphore(upload_id_path: &str) -> Arc<tokio::sync::Semaphore> {
+    CAPPED_MULTIPART_STAGING
+        .get_or_init(|| Mutex::new(HashMap::new()))
+        .lock()
+        .expect("capped multipart staging semaphore map should not be poisoned")
+        .entry(upload_id_path.to_owned())
+        .or_insert_with(|| Arc::new(tokio::sync::Semaphore::new(1)))
+        .clone()
+}
+
+fn remove_capped_multipart_staging_semaphore(upload_id_path: &str) {
+    if let Some(map) = CAPPED_MULTIPART_STAGING.get() {
+        let mut map = map
+            .lock()
+            .expect("capped multipart staging semaphore map should not be poisoned");
+        let removable = map
+            .get(upload_id_path)
+            .is_some_and(|semaphore| Arc::strong_count(semaphore) == 1);
+        if removable {
+            map.remove(upload_id_path);
+        }
+    }
+}
+
+fn multipart_size_limit_from_metadata(metadata: &HashMap<String, String>) -> Result<Option<u64>> {
+    if !contains_key_str(metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE) {
+        return Ok(None);
+    }
+
+    let Some(value) = get_consistent_str(metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE) else {
+        return Err(Error::InvalidArgument(
+            "multipart upload".to_string(),
+            SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+            "missing or conflicting internal size limit".to_string(),
+        ));
+    };
+
+    let limit = value.parse::<u64>().map_err(|_| {
+        Error::InvalidArgument(
+            "multipart upload".to_string(),
+            SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+            "invalid internal size limit".to_string(),
+        )
+    })?;
+    Ok(Some(limit))
+}
+
+fn admitted_multipart_size(current: u64, candidate: u64, limit: u64) -> Result<u64> {
+    let total = current.checked_add(candidate).ok_or_else(|| {
+        Error::InvalidArgument(
+            "multipart upload".to_string(),
+            SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+            "logical size overflow".to_string(),
+        )
+    })?;
+    if total > limit {
+        return Err(Error::EntityTooLarge(total, limit));
+    }
+    Ok(total)
+}
+
 pub(crate) struct StaleMultipartCleanupGuard {
     file_info: FileInfo,
     upload_path: String,
@@ -115,8 +194,13 @@ impl StaleMultipartCleanupGuard {
 
     pub(crate) async fn delete(self, set: &SetDisks) -> Result<()> {
         fence_commit_on_lock_loss(Some(&self.lock_guard), "stale_multipart_cleanup", &self.upload_path)?;
-        set.delete_all_with_quorum(RUSTFS_META_MULTIPART_BUCKET, &self.upload_path, self.write_quorum)
+        let result = set
-            .await
+            .delete_all_with_quorum(RUSTFS_META_MULTIPART_BUCKET, &self.upload_path, self.write_quorum)
+            .await;
+        if result.is_ok() {
+            remove_capped_multipart_staging_semaphore(&self.upload_path);
+        }
+        result
     }
 }
 
@@ -635,6 +719,61 @@ async fn multipart_upload_paths_on_disk(disk: DiskStore, bucket: &str) -> disk::
 }
 
 impl SetDisks {
+    async fn current_multipart_logical_size(
+        &self,
+        bucket: &str,
+        object: &str,
+        upload_id: &str,
+        upload_id_path: &str,
+        fi: &FileInfo,
+        replacing_part: usize,
+    ) -> Result<u64> {
+        let online_disks = self.get_disks_internal().await;
+        let read_quorum = fi.read_quorum(self.default_read_quorum());
+        let part_path = format!(
+            "{}{}",
+            path_join_buf(&[
+                upload_id_path,
+                fi.data_dir.map(|v| v.to_string()).unwrap_or_default().as_str(),
+            ]),
+            SLASH_SEPARATOR
+        );
+        let part_numbers = match Self::list_parts(&online_disks, &part_path, read_quorum).await {
+            Ok(parts) => parts,
+            Err(DiskError::FileNotFound) => return Ok(0),
+            Err(err) => return Err(to_object_err(err.into(), vec![bucket, object, upload_id])),
+        };
+        if part_numbers.is_empty() {
+            return Ok(0);
+        }
+        let part_meta_paths = part_numbers
+            .iter()
+            .map(|number| format!("{part_path}part.{number}.meta"))
+            .collect::<Vec<_>>();
+        let existing_parts =
+            Self::read_parts(&online_disks, RUSTFS_META_MULTIPART_BUCKET, &part_meta_paths, &part_numbers, read_quorum)
+                .await
+                .map_err(|err| to_object_err(err.into(), vec![bucket, object, upload_id]))?;
+
+        existing_parts.into_iter().try_fold(0_u64, |total, part| {
+            if part.error.is_some() || part.number == replacing_part {
+                return if part.error.is_some() {
+                    Err(Error::PartMissingOrCorrupt)
+                } else {
+                    Ok(total)
+                };
+            }
+            let part_size = u64::try_from(part.actual_size).map_err(|_| Error::PartMissingOrCorrupt)?;
+            total.checked_add(part_size).ok_or_else(|| {
+                Error::InvalidArgument(
+                    "multipart upload".to_string(),
+                    SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+                    "logical size overflow".to_string(),
+                )
+            })
+        })
+    }
+
     async fn discover_multipart_upload_paths(
         &self,
         orig_bucket: &str,
@@ -1130,9 +1269,18 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
         crate::hp_guard!("SetDisks::put_object_part");
         let upload_id_path = Self::get_multipart_upload_dir(bucket, object, upload_id, opts.data_movement);
 
-        let (fi, _) = self
+        let (fi, _) = match self
             .check_upload_id_exists_with_opts(bucket, object, upload_id, true, opts)
-            .await?;
+            .await
+        {
+            Ok(value) => value,
+            Err(err @ Error::InvalidUploadID(..)) => {
+                remove_capped_multipart_staging_semaphore(&upload_id_path);
+                return Err(err);
+            }
+            Err(err) => return Err(err),
+        };
+        let multipart_size_limit = multipart_size_limit_from_metadata(&fi.metadata)?;
         ensure_data_movement_upload_access(&fi, bucket, object, upload_id, opts)?;
         ensure_multipart_bucket_incarnation(&self.ctx, &fi, bucket, object, upload_id, opts.expected_bucket_incarnation_id)
             .await?;
@@ -1165,6 +1313,44 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
         let part_suffix = format!("part.{part_id}");
         let tmp_part = format!("{}x{}", Uuid::new_v4(), OffsetDateTime::now_utc().unix_timestamp());
         let tmp_part_path = Arc::new(format!("{tmp_part}/{part_suffix}"));
+        let part_path = format!("{}/{}/{}", upload_id_path, fi.data_dir.unwrap_or_default(), part_suffix);
+        let part_lock_path = format!("{upload_id_path}/{part_suffix}");
+
+        // Keep at most one capped part staging locally per upload. The
+        // distributed lock below is held only for the durable admission check;
+        // it is reacquired for the short final rename, so Complete/Abort are
+        // not blocked behind a slow body upload.
+        let _capped_staging_guard = if multipart_size_limit.is_some() {
+            Some(CappedMultipartStagingGuard {
+                upload_id_path: upload_id_path.clone(),
+                permit: Some(
+                    capped_multipart_staging_semaphore(&upload_id_path)
+                        .acquire_owned()
+                        .await
+                        .map_err(|_| Error::other("capped multipart staging semaphore closed"))?,
+                ),
+            })
+        } else {
+            None
+        };
+
+        if let Some(limit) = multipart_size_limit {
+            let admission_guard = self
+                .acquire_write_lock_diag("put_object_part_admission", RUSTFS_META_MULTIPART_BUCKET, &upload_id_path)
+                .await?;
+            let declared_size = if data.size() >= 0 {
+                u64::try_from(data.size()).map_err(|_| Error::PartMissingOrCorrupt)?
+            } else if data.actual_size() >= 0 {
+                u64::try_from(data.actual_size()).map_err(|_| Error::PartMissingOrCorrupt)?
+            } else {
+                return Err(Error::PartMissingOrCorrupt);
+            };
+            let current_size = self
+                .current_multipart_logical_size(bucket, object, upload_id, &upload_id_path, &fi, part_id)
+                .await?;
+            admitted_multipart_size(current_size, declared_size, limit)?;
+            drop(admission_guard);
+        }
 
         let result: Result<PartInfo> = async {
             let erasure =
@@ -1365,30 +1551,21 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
                 .await?;
             }
 
-            let part_path = format!("{}/{}/{}", upload_id_path, fi.data_dir.unwrap_or_default(), part_suffix);
-            let part_lock_path = format!("{upload_id_path}/{part_suffix}");
-
             #[cfg(test)]
             pause_multipart_commit(bucket, object, MultipartCommitPause::PutPartBeforeLockAcquire).await;
-            // Serialize only same-part commits (rename_part), not the whole upload.
+            // Capped uploads reacquire the upload-wide write lock for the
-            // Each concurrent stream writes to its own unique temp dir (see
+            // final durable check and rename. Uncapped uploads retain the
-            // `tmp_part` above), so the encode/stream phase never conflicts and must
+            // concurrent encode path and only serialize the final same-part
-            // stay lock-free — holding a lock across it would serialize slow
+            // rename; completion/abort use the upload-wide write lock.
-            // re-transmits of the same part and defeat the S3 "last finisher wins"
+            let (_upload_commit_guard, _part_commit_guard) = if multipart_size_limit.is_some() {
-            // semantics. The mixed-generation hazard is confined to rename_part,
+                let upload_guard = self
-            // where two temp parts are moved cross-disk onto the SAME final
+                    .acquire_write_lock_diag("put_object_part_commit", RUSTFS_META_MULTIPART_BUCKET, &upload_id_path)
-            // part_path: interleaving there can leave shards from two generations,
+                    .await?;
-            // each individually bitrot-valid, that only surface as silent corruption
+                let part_guard = self
-            // at read time (backlog#853). A write lock scoped to this part number
+                    .acquire_write_lock_diag("put_object_part_commit", RUSTFS_META_MULTIPART_BUCKET, &part_lock_path)
-            // makes each same-part commit atomic across disks, so the last committer
+                    .await?;
-            // wins consistently, while different part numbers commit onto disjoint
+                (Some(upload_guard), Some(part_guard))
-            // part paths and stay concurrent (issue#5961 — an uploadId-wide write
+            } else if opts.no_lock {
-            // lock serialized them into 503 lock-acquire timeouts). The shared
-            // uploadId read lock keeps completion/abort (which take the uploadId
-            // write lock) from racing any in-flight part commit; a guarded
-            // completion takes the object lock before the upload lock to preserve
-            // global ordering.
-            let (_upload_commit_guard, _part_commit_guard) = if opts.no_lock {
                 (None, None)
             } else {
                 let upload_guard = self
@@ -1400,8 +1577,16 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
                 (Some(upload_guard), Some(part_guard))
             };
             let (commit_fi, _) = self
-                .check_upload_id_exists_with_opts(bucket, object, upload_id, false, opts)
+                .check_upload_id_exists_with_opts(bucket, object, upload_id, multipart_size_limit.is_some(), opts)
                 .await?;
+            let commit_size_limit = multipart_size_limit_from_metadata(&commit_fi.metadata)?;
+            if commit_size_limit != multipart_size_limit {
+                return Err(Error::InvalidArgument(
+                    "multipart upload".to_string(),
+                    SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+                    "size limit metadata changed or is missing".to_string(),
+                ));
+            }
             ensure_data_movement_upload_access(&commit_fi, bucket, object, upload_id, opts)?;
             ensure_multipart_bucket_incarnation(
                 &self.ctx,
@@ -1431,6 +1616,14 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
             }
             ensure_multipart_bucket_lifecycle_lock_held(bucket, object, opts)?;
 
+            if let Some(limit) = commit_size_limit {
+                let current_size = self
+                    .current_multipart_logical_size(bucket, object, upload_id, &upload_id_path, &commit_fi, part_id)
+                    .await?;
+                let candidate_size = u64::try_from(actual_size).map_err(|_| Error::PartMissingOrCorrupt)?;
+                admitted_multipart_size(current_size, candidate_size, limit)?;
+            }
+
             let _ = self
                 .rename_part(
                     &shuffle_disks,
@@ -1891,12 +2084,17 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
         ensure_multipart_bucket_lifecycle_lock_held(bucket, object, opts)?;
         let upload_id_path = Self::get_multipart_upload_dir(bucket, object, upload_id, opts.data_movement);
 
-        self.delete_all_with_quorum(
+        let result = self
-            RUSTFS_META_MULTIPART_BUCKET,
+            .delete_all_with_quorum(
-            &upload_id_path,
+                RUSTFS_META_MULTIPART_BUCKET,
-            fi.write_quorum(self.default_write_quorum()),
+                &upload_id_path,
-        )
+                fi.write_quorum(self.default_write_quorum()),
-        .await
+            )
+            .await;
+        if result.is_ok() {
+            remove_capped_multipart_staging_semaphore(&upload_id_path);
+        }
+        result
     }
     // complete_multipart_upload finished
     #[tracing::instrument(skip(self))]
@@ -2016,6 +2214,27 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
             return Err(Error::other("part result number err"));
         }
 
+        if let Some(limit) = multipart_size_limit_from_metadata(&fi.metadata)? {
+            let mut total = 0_u64;
+            for part in &object_parts {
+                if part.error.is_some() {
+                    return Err(Error::PartMissingOrCorrupt);
+                }
+                let part_size = u64::try_from(part.actual_size).map_err(|_| Error::PartMissingOrCorrupt)?;
+                total = total.checked_add(part_size).ok_or_else(|| {
+                    Error::InvalidArgument(
+                        "multipart upload".to_string(),
+                        SUFFIX_MAX_TOTAL_OBJECT_SIZE.to_string(),
+                        "logical size overflow".to_string(),
+                    )
+                })?;
+            }
+            if total > limit {
+                return Err(Error::EntityTooLarge(total, limit));
+            }
+            rustfs_utils::http::metadata_compat::remove_str(&mut fi.metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE);
+        }
+
         let mut checksum_type = rustfs_rio::ChecksumType::NONE;
 
         if let Some(cs) = fi.metadata.get(rustfs_rio::RUSTFS_MULTIPART_CHECKSUM) {
@@ -3024,13 +3243,17 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
             Ok(ObjectInfo::from_file_info(&fi, &commit_bucket, &commit_object, commit_is_versioned))
         };
 
-        if detach_commit_owner {
+        let result = if detach_commit_owner {
             tokio::spawn(commit)
                 .await
                 .map_err(|err| Error::other(format!("complete_multipart_upload commit task failed: {err}")))?
         } else {
             commit.await
+        };
+        if result.is_ok() {
+            remove_capped_multipart_staging_semaphore(&upload_id_path);
         }
+        result
     }
 }
 
@@ -3096,6 +3319,34 @@ mod tests {
         assert!(multipart_bucket_incarnation_id(&nil_metadata).is_err());
     }
 
+    #[test]
+    fn multipart_size_limit_metadata_is_dual_key_and_fail_closed() {
+        let mut metadata = HashMap::new();
+        insert_str(&mut metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE, "100".to_string());
+        assert_eq!(multipart_size_limit_from_metadata(&metadata).unwrap(), Some(100));
+
+        metadata.insert("x-minio-internal-max-total-object-size".to_string(), "101".to_string());
+        assert!(multipart_size_limit_from_metadata(&metadata).is_err());
+
+        let mut invalid = HashMap::new();
+        insert_str(&mut invalid, SUFFIX_MAX_TOTAL_OBJECT_SIZE, "-1".to_string());
+        assert!(multipart_size_limit_from_metadata(&invalid).is_err());
+    }
+
+    #[test]
+    fn multipart_size_admission_handles_boundaries_and_overflow() {
+        assert_eq!(admitted_multipart_size(90, 10, 100).unwrap(), 100);
+        assert!(matches!(
+            admitted_multipart_size(90, 11, 100),
+            Err(StorageError::EntityTooLarge(101, 100))
+        ));
+        assert!(admitted_multipart_size(u64::MAX - 1, 1, u64::MAX).is_ok());
+        assert!(matches!(
+            admitted_multipart_size(u64::MAX, 1, u64::MAX),
+            Err(StorageError::InvalidArgument(_, _, _))
+        ));
+    }
+
     #[test]
     fn multipart_bucket_incarnation_gate_accepts_only_current_or_same_lifetime_legacy_uploads() {
         let expected = Uuid::new_v4();

crates/storage-api/src/error.rs

@@ -81,6 +81,7 @@ pub enum StorageErrorCode {
     InsufficientWriteQuorum,
     PreconditionFailed,
     EntityTooSmall,
+    EntityTooLarge,
     InvalidRangeSpec,
     NotModified,
     InvalidPartNumber,
@@ -169,6 +170,7 @@ impl StorageErrorCode {
             Self::InsufficientWriteQuorum => 0x3A,
             Self::PreconditionFailed => 0x3B,
             Self::EntityTooSmall => 0x3C,
+            Self::EntityTooLarge => 0x56,
             Self::InvalidRangeSpec => 0x3D,
             Self::NotModified => 0x3E,
             Self::InvalidPartNumber => 0x3F,
@@ -257,6 +259,7 @@ impl StorageErrorCode {
             0x3A => Some(Self::InsufficientWriteQuorum),
             0x3B => Some(Self::PreconditionFailed),
             0x3C => Some(Self::EntityTooSmall),
+            0x56 => Some(Self::EntityTooLarge),
             0x3D => Some(Self::InvalidRangeSpec),
             0x3E => Some(Self::NotModified),
             0x3F => Some(Self::InvalidPartNumber),
@@ -350,6 +353,7 @@ mod tests {
         (StorageErrorCode::InsufficientWriteQuorum, 0x3A),
         (StorageErrorCode::PreconditionFailed, 0x3B),
         (StorageErrorCode::EntityTooSmall, 0x3C),
+        (StorageErrorCode::EntityTooLarge, 0x56),
         (StorageErrorCode::InvalidRangeSpec, 0x3D),
         (StorageErrorCode::NotModified, 0x3E),
         (StorageErrorCode::InvalidPartNumber, 0x3F),

crates/utils/src/http/metadata_compat.rs

@@ -44,6 +44,8 @@ pub const SUFFIX_COMPRESSION: &str = "compression";
 pub const SUFFIX_REPLICATION_PRESERVE_CIPHERTEXT: &str = "replication-preserve-ciphertext";
 pub const SUFFIX_COMPRESSION_SIZE: &str = "compression-size";
 pub const SUFFIX_ACTUAL_SIZE: &str = "actual-size";
+/// Maximum logical object size for a capability-bound multipart upload.
+pub const SUFFIX_MAX_TOTAL_OBJECT_SIZE: &str = "max-total-object-size";
 pub const SUFFIX_ACTUAL_OBJECT_SIZE: &str = "actual-object-size";
 /// Used by replication; key stored with capital A
 pub const SUFFIX_ACTUAL_OBJECT_SIZE_CAP: &str = "Actual-Object-Size";

docs/operations/presigned-multipart-size-limit.md

@@ -0,0 +1,55 @@
+# Presigned multipart total-size limit
+
+RustFS V2 supports an optional capability on a signed or SigV4-presigned
+`CreateMultipartUpload` request:
+
+```text
+x-rustfs-max-total-object-size=<unsigned 64-bit integer>
+```
+
+The backend must include the parameter before calculating the SigV4
+signature. It is part of the canonical query and cannot be added, removed, or
+changed by the browser. RustFS stores the verified limit in the multipart
+upload session and applies it to every `UploadPart` and to
+`CompleteMultipartUpload`.
+
+Backend pseudocode (the custom query must be present before signing):
+
+```text
+uri = "/photos/archive.zip?uploads"
+uri += "&x-rustfs-max-total-object-size=104857600"
+presigned_url = sigv4_presign("POST", uri, credentials)
+# Return presigned_url to the browser. Never append the parameter afterwards.
+```
+
+The resulting flow is:
+
+1. The backend signs `CreateMultipartUpload?...&x-rustfs-max-total-object-size=104857600`.
+2. RustFS verifies the SigV4 request and persists the limit with the upload ID.
+3. The browser uploads parts using the returned upload ID.
+4. RustFS rejects a part whose declared logical size would exceed the remaining
+   budget and rejects completion if the server-side part metadata exceeds the
+   limit.
+
+The limit is measured in logical object bytes (`actual_size`), not erasure,
+encryption, or compression bytes. Replacing an existing part uses replacement
+semantics: the old part size is removed before the new part size is admitted.
+Unknown-length parts are rejected for capped sessions rather than buffered
+without a bound. Capped parts are admitted under an upload-wide write lock
+before temporary shards are created and use a per-upload staging permit to
+bound local in-flight data. The distributed lock is released while the body is
+read and reacquired for the final check/rename, so Complete and Abort are not
+blocked behind a slow upload. The normal request-body stall timeout releases
+the staging permit when a client stops sending.
+
+The parameter is accepted only on `CreateMultipartUpload`. Supplying it on
+`UploadPart`, `CompleteMultipartUpload`, `AbortMultipartUpload`, listing, or
+copy operations returns `InvalidRequest`; those requests use the persisted
+session state. A multipart upload created without this parameter remains
+unlimited for backward compatibility. The V1 single-request capability
+(`x-rustfs-max-content-length`) is independent and is not a multipart limit.
+
+Because enforcement happens in the multipart data plane, every node that may
+receive requests for a capped upload must run the V2 implementation. During a
+rolling upgrade, route capped uploads only to upgraded nodes; older nodes treat
+the internal metadata as unknown and cannot enforce the limit.

rustfs/src/app/multipart_usecase.rs

@@ -67,6 +67,7 @@ use super::storage_api::multipart_usecase::sse::{
 use super::storage_api::multipart_usecase::{
     StorageObjectInfo as ObjectInfo, StorageObjectOptions as ObjectOptions, StoragePutObjReader as PutObjReader,
 };
+use crate::app::object::{guard_put_object_body_read_timeout, put_object_body_read_timeout};
 use crate::app::object_data_cache::{
     ObjectDataCacheAdapter, invalidate_object_data_cache_after_complete_multipart_success,
     invalidate_object_data_cache_before_mutation,
@@ -78,7 +79,11 @@ use crate::app::object_usecase::{
 use crate::app::runtime_sources::{
     AppContext, current_app_context, current_object_data_cache_for_context, current_object_store_handle_for_context,
 };
-use crate::auth::{VerifiedPresignedRequest, reject_presigned_put_max_content_length_for_other_operation};
+use crate::auth::{
+    VerifiedPresignedRequest, VerifiedSigV4Request, parse_presigned_multipart_max_total_object_size,
+    reject_presigned_multipart_max_total_object_size_for_other_operation,
+    reject_presigned_put_max_content_length_for_other_operation,
+};
 use crate::capacity::record_capacity_write;
 use crate::error::ApiError;
 use crate::table_catalog;
@@ -92,8 +97,9 @@ use rustfs_utils::CompressionAlgorithm;
 #[cfg(test)]
 use rustfs_utils::http::insert_header;
 use rustfs_utils::http::{
-    SUFFIX_REPLICATION_PRESERVE_CIPHERTEXT, SUFFIX_REPLICATION_STATUS, SUFFIX_REPLICATION_TIMESTAMP,
+    SUFFIX_MAX_TOTAL_OBJECT_SIZE, SUFFIX_REPLICATION_PRESERVE_CIPHERTEXT, SUFFIX_REPLICATION_STATUS,
-    SUFFIX_SOURCE_REPLICATION_REQUEST, contains_key_str, get_header, get_source_scheme,
+    SUFFIX_REPLICATION_TIMESTAMP, SUFFIX_SOURCE_REPLICATION_REQUEST, contains_key_str, get_consistent_str, get_header,
+    get_source_scheme,
     headers::{AMZ_DECODED_CONTENT_LENGTH, AMZ_OBJECT_TAGGING, AMZ_STORAGE_CLASS},
     insert_str,
 };
@@ -108,6 +114,7 @@ use s3s::{S3Error, S3ErrorCode, S3Request, S3Response, S3Result, s3_error};
 use std::collections::{HashMap, HashSet};
 use std::str::FromStr;
 use std::sync::Arc;
+use std::time::Duration;
 use tokio::sync::RwLock;
 use tokio_util::io::StreamReader;
 use tracing::{instrument, warn};
@@ -226,6 +233,22 @@ fn create_multipart_upload_metadata(
     metadata
 }
 
+fn multipart_max_total_object_size(metadata: &HashMap<String, String>) -> S3Result<Option<u64>> {
+    if !contains_key_str(metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE) {
+        return Ok(None);
+    }
+
+    let value = get_consistent_str(metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE).ok_or_else(|| {
+        S3Error::with_message(
+            S3ErrorCode::InvalidRequest,
+            "multipart size capability metadata is missing or inconsistent".to_string(),
+        )
+    })?;
+    value.parse::<u64>().map(Some).map_err(|_| {
+        S3Error::with_message(S3ErrorCode::InvalidRequest, "multipart size capability metadata is invalid".to_string())
+    })
+}
+
 /// A multipart session advertises disk compression only when the staged-rollout
 /// switch (`RUSTFS_COMPRESSION_MULTIPART_ENABLED`) is on, the object key/headers
 /// qualify, AND the session is not an SSE-C ciphertext-passthrough replication
@@ -398,6 +421,11 @@ impl DefaultMultipartUsecase {
         &self,
         req: S3Request<AbortMultipartUploadInput>,
     ) -> S3Result<S3Response<AbortMultipartUploadOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -444,6 +472,11 @@ impl DefaultMultipartUsecase {
         &self,
         req: S3Request<CompleteMultipartUploadInput>,
     ) -> S3Result<S3Response<CompleteMultipartUploadOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -752,6 +785,11 @@ impl DefaultMultipartUsecase {
         &self,
         req: S3Request<CreateMultipartUploadInput>,
     ) -> S3Result<S3Response<CreateMultipartUploadOutput>> {
+        let multipart_max_total_object_size = parse_presigned_multipart_max_total_object_size(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -807,6 +845,9 @@ impl DefaultMultipartUsecase {
         )?;
 
         let mut metadata = create_multipart_upload_metadata(input_metadata, &req.headers, tagging, storage_class.as_ref());
+        if let Some(limit) = multipart_max_total_object_size {
+            insert_str(&mut metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE, limit.to_string());
+        }
 
         let has_explicit_object_lock_retention = object_lock_mode.is_some()
             || object_lock_retain_until_date.is_some()
@@ -978,6 +1019,11 @@ impl DefaultMultipartUsecase {
     #[instrument(level = "debug", skip(self, req))]
     #[hotpath::measure(impl_type = "MultipartUsecase")]
     pub async fn execute_upload_part(&self, req: S3Request<UploadPartInput>) -> S3Result<S3Response<UploadPartOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -1006,6 +1052,40 @@ impl DefaultMultipartUsecase {
 
         let mut size = resolve_upload_part_size(&req.headers, content_length)?;
         let mut body_stream = body.ok_or_else(|| s3_error!(IncompleteBody))?;
+        let Some(store) = self.object_store() else {
+            return Err(S3Error::with_message(S3ErrorCode::InternalError, "Not init".to_string()));
+        };
+        let fi = store
+            .get_multipart_info(&bucket, &key, &upload_id, &opts)
+            .await
+            .map_err(ApiError::from)?;
+        let max_total_object_size = multipart_max_total_object_size(&fi.user_defined)?;
+        if max_total_object_size.is_some() && size.is_some_and(|size| size < 0) {
+            return Err(S3Error::new(S3ErrorCode::UnexpectedContent));
+        }
+        if max_total_object_size.is_some() && size.is_none() {
+            return Err(S3Error::new(S3ErrorCode::UnexpectedContent));
+        }
+        if let (Some(limit), Some(size)) = (max_total_object_size, size)
+            && u64::try_from(size).is_ok_and(|size| size > limit)
+        {
+            return Err(S3Error::new(S3ErrorCode::EntityTooLarge));
+        }
+        if max_total_object_size.is_some() {
+            let request_id = req
+                .extensions
+                .get::<super::storage_api::multipart_usecase::request_context::RequestContext>()
+                .map(|ctx| ctx.request_id.clone())
+                .unwrap_or_default();
+            body_stream = guard_put_object_body_read_timeout(
+                body_stream,
+                &bucket,
+                &key,
+                &request_id,
+                content_length,
+                put_object_body_read_timeout().max(Duration::from_secs(rustfs_config::DEFAULT_HTTP_REQUEST_BODY_READ_TIMEOUT)),
+            );
+        }
 
         if size.is_none() {
             let mut total = 0i64;
@@ -1026,16 +1106,6 @@ impl DefaultMultipartUsecase {
             body_stream = StreamingBlob::wrap(stream);
         }
 
-        // Get multipart info early to check if managed encryption will be applied
-        let Some(store) = self.object_store() else {
-            return Err(S3Error::with_message(S3ErrorCode::InternalError, "Not init".to_string()));
-        };
-
-        let fi = store
-            .get_multipart_info(&bucket, &key, &upload_id, &opts)
-            .await
-            .map_err(ApiError::from)?;
-
         let mut size = size.ok_or_else(|| s3_error!(UnexpectedContent))?;
         let ingress_stage_start = rustfs_io_metrics::put_stage_metrics_enabled().then(std::time::Instant::now);
 
@@ -1250,6 +1320,11 @@ impl DefaultMultipartUsecase {
         &self,
         req: S3Request<ListMultipartUploadsInput>,
     ) -> S3Result<S3Response<ListMultipartUploadsOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -1302,6 +1377,11 @@ impl DefaultMultipartUsecase {
     }
 
     pub async fn execute_list_parts(&self, req: S3Request<ListPartsInput>) -> S3Result<S3Response<ListPartsOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -1338,6 +1418,11 @@ impl DefaultMultipartUsecase {
         &self,
         req: S3Request<UploadPartCopyInput>,
     ) -> S3Result<S3Response<UploadPartCopyOutput>> {
+        reject_presigned_multipart_max_total_object_size_for_other_operation(
+            &req.headers,
+            req.uri.query(),
+            req.extensions.get::<VerifiedSigV4Request>().is_some(),
+        )?;
         reject_presigned_put_max_content_length_for_other_operation(
             &req.headers,
             req.uri.query(),
@@ -1441,6 +1526,7 @@ impl DefaultMultipartUsecase {
             .get_multipart_info(&bucket, &key, &upload_id, &dst_opts)
             .await
             .map_err(ApiError::from)?;
+        let destination_size_limit = multipart_max_total_object_size(&mp_info.user_defined)?;
         EncryptionRequest {
             bucket: &bucket,
             key: &key,
@@ -1523,19 +1609,25 @@ impl DefaultMultipartUsecase {
             return Err(s3_error!(PreconditionFailed));
         }
 
+        let source_logical_size = match src_info.get_actual_size() {
+            Ok(size) if size >= 0 => size,
+            Ok(_) | Err(_) if destination_size_limit.is_some() => {
+                return Err(S3Error::new(S3ErrorCode::UnexpectedContent));
+            }
+            Ok(_) | Err(_) => src_info.size,
+        };
+
         let (_start_offset, length) = if let Some(ref range_spec) = rs {
             // Copy-source ranges are expressed over the logical plaintext object.
             // Encrypted (and compressed) objects have a larger or smaller physical
             // representation, so validating against `size` rejects valid later parts.
-            let validation_size = src_info.get_actual_size().unwrap_or(src_info.size);
+            validate_copy_source_range_not_exceeds(range_spec, source_logical_size)?;
-
-            validate_copy_source_range_not_exceeds(range_spec, validation_size)?;
 
             range_spec
-                .get_offset_length(validation_size)
+                .get_offset_length(source_logical_size)
                 .map_err(|e| S3Error::with_message(S3ErrorCode::InvalidRange, e.to_string()))?
         } else {
-            (0, src_info.size)
+            (0, source_logical_size)
         };
 
         let is_disk_compressed =
@@ -2137,6 +2229,16 @@ mod tests {
         assert_eq!(metadata.get(AMZ_OBJECT_TAGGING), Some(&"project=rustfs".to_string()));
     }
 
+    #[test]
+    fn multipart_max_total_object_size_reads_compatible_internal_metadata() {
+        let mut metadata = HashMap::new();
+        insert_str(&mut metadata, SUFFIX_MAX_TOTAL_OBJECT_SIZE, "104857600".to_string());
+        assert_eq!(multipart_max_total_object_size(&metadata).unwrap(), Some(104_857_600));
+
+        metadata.insert("x-minio-internal-max-total-object-size".to_string(), "1".to_string());
+        assert!(multipart_max_total_object_size(&metadata).is_err());
+    }
+
     #[tokio::test]
     async fn execute_complete_multipart_upload_rejects_missing_parts_payload() {
         let input = CompleteMultipartUploadInput::builder()

rustfs/src/app/object/mod.rs

@@ -195,6 +195,7 @@ pub(crate) use self::delete::*;
 pub(crate) use self::extract::*;
 pub(crate) use self::get::*;
 use self::put::*;
+pub(crate) use self::put::{guard_put_object_body_read_timeout, put_object_body_read_timeout};
 pub(crate) use self::shared::*;
 #[cfg(test)]
 use self::test_support::*;

rustfs/src/app/object/put.rs

@@ -90,7 +90,7 @@ fn resolve_put_object_authoritative_size(headers: &HeaderMap, content_length: Op
 /// Returns `Duration::ZERO` when disabled (`RUSTFS_HTTP_REQUEST_BODY_READ_TIMEOUT=0`),
 /// in which case [`guard_put_object_body_read_timeout`] passes the body through
 /// untouched.
-fn put_object_body_read_timeout() -> Duration {
+pub(crate) fn put_object_body_read_timeout() -> Duration {
     Duration::from_secs(rustfs_utils::get_env_u64(
         rustfs_config::ENV_HTTP_REQUEST_BODY_READ_TIMEOUT,
         rustfs_config::DEFAULT_HTTP_REQUEST_BODY_READ_TIMEOUT,
@@ -260,7 +260,7 @@ impl ByteStream for RequestBodyReadTimeout {
 /// Wrap an incoming request body with [`RequestBodyReadTimeout`] unless the
 /// feature is disabled (`timeout == 0`), in which case the body is returned
 /// untouched. `remaining_length` is preserved via [`StreamingBlob::new`].
-fn guard_put_object_body_read_timeout(
+pub(crate) fn guard_put_object_body_read_timeout(
     body: StreamingBlob,
     bucket: &str,
     key: &str,

rustfs/src/auth.rs

@@ -53,6 +53,7 @@ const EVENT_SESSION_TOKEN_EXTRACTION: &str = "session_token_extraction";
 
 /// RustFS-specific query capability for a single presigned PutObject request.
 pub(crate) const RUSTFS_MAX_CONTENT_LENGTH_QUERY: &str = "x-rustfs-max-content-length";
+pub(crate) const RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY: &str = "x-rustfs-max-total-object-size";
 
 /// Inserted by the S3 access boundary after the upstream verifier accepts a
 /// request as SigV4 presigned. Downstream capability parsing must require this
@@ -60,6 +61,9 @@ pub(crate) const RUSTFS_MAX_CONTENT_LENGTH_QUERY: &str = "x-rustfs-max-content-l
 #[derive(Debug, Clone, Copy)]
 pub(crate) struct VerifiedPresignedRequest;
 
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct VerifiedSigV4Request;
+
 /// Performs constant-time string comparison to prevent timing attacks.
 ///
 /// This function should be used when comparing sensitive values like passwords,
@@ -1111,6 +1115,92 @@ pub(crate) fn reject_presigned_put_max_content_length_for_other_operation(
     Ok(())
 }
 
+/// Parse the V2 multipart total-size capability after SigV4 authentication.
+/// Header-authenticated CreateMultipartUpload requests are accepted because the
+/// custom query is covered by the SigV4 canonical request; later multipart
+/// operations read the immutable value from the upload session metadata.
+pub(crate) fn parse_presigned_multipart_max_total_object_size(
+    header: &HeaderMap,
+    query: Option<&str>,
+    verified_sigv4: bool,
+) -> S3Result<Option<u64>> {
+    let Some(query) = query else {
+        return Ok(None);
+    };
+
+    let mut value = None;
+    let mut decoded_query = Vec::new();
+    for (name, candidate) in form_urlencoded::parse(query.as_bytes()) {
+        decoded_query.push((name.to_string(), candidate.to_string()));
+        if name == RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY {
+            if value.is_some() {
+                return Err(S3Error::with_message(
+                    S3ErrorCode::InvalidRequest,
+                    format!("{RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY} must appear exactly once"),
+                ));
+            }
+            value = Some(candidate.into_owned());
+        } else if name.eq_ignore_ascii_case(RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY) {
+            return Err(S3Error::with_message(
+                S3ErrorCode::InvalidRequest,
+                format!("query parameter name must be exactly {RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY}"),
+            ));
+        }
+    }
+
+    let Some(value) = value else {
+        return Ok(None);
+    };
+
+    let auth_type = get_request_auth_type_with_query(header, Some(query));
+    let is_presigned = matches!(auth_type, AuthType::Presigned);
+    let is_header_signed = matches!(auth_type, AuthType::Signed);
+    let complete_presigned_query = [
+        ("x-amz-algorithm", "AWS4-HMAC-SHA256"),
+        ("x-amz-date", ""),
+        ("x-amz-expires", ""),
+        ("x-amz-signedheaders", ""),
+        ("x-amz-credential", ""),
+        ("x-amz-signature", ""),
+    ]
+    .into_iter()
+    .all(|(name, expected)| {
+        decoded_query
+            .iter()
+            .find(|(candidate, _)| candidate.eq_ignore_ascii_case(name))
+            .is_some_and(|(_, candidate)| !candidate.is_empty() && (expected.is_empty() || candidate == expected))
+    });
+
+    let authenticated = verified_sigv4 && (is_header_signed || (is_presigned && complete_presigned_query));
+    if !authenticated {
+        return Err(S3Error::with_message(
+            S3ErrorCode::InvalidRequest,
+            format!("{RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY} requires a verified SigV4 request"),
+        ));
+    }
+
+    value.parse::<u64>().map(Some).map_err(|_| {
+        S3Error::with_message(
+            S3ErrorCode::InvalidRequest,
+            format!("{RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY} must be a non-negative 64-bit integer"),
+        )
+    })
+}
+
+pub(crate) fn reject_presigned_multipart_max_total_object_size_for_other_operation(
+    header: &HeaderMap,
+    query: Option<&str>,
+    verified_sigv4: bool,
+) -> S3Result<()> {
+    if parse_presigned_multipart_max_total_object_size(header, query, verified_sigv4)?.is_some() {
+        return Err(S3Error::with_message(
+            S3ErrorCode::InvalidRequest,
+            format!("{RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY} is only supported for CreateMultipartUpload"),
+        ));
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1816,6 +1906,52 @@ mod tests {
         }
     }
 
+    #[test]
+    fn multipart_max_total_object_size_requires_signed_create_request() {
+        let headers = HeaderMap::new();
+        let signed_prefix = "X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20260827T000000Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Credential=test/20260827/us-east-1/s3/aws4_request&X-Amz-Signature=signature";
+        let query = format!("{signed_prefix}&x-rustfs-max-total-object-size=104857600");
+
+        assert_eq!(
+            parse_presigned_multipart_max_total_object_size(&headers, Some(&query), true).unwrap(),
+            Some(104_857_600)
+        );
+        assert_eq!(
+            reject_presigned_multipart_max_total_object_size_for_other_operation(&headers, Some(&query), true)
+                .unwrap_err()
+                .code(),
+            &S3ErrorCode::InvalidRequest
+        );
+    }
+
+    #[test]
+    fn multipart_max_total_object_size_rejects_tampering_and_invalid_values() {
+        let headers = HeaderMap::new();
+        let signed_prefix = "X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20260827T000000Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Credential=test/20260827/us-east-1/s3/aws4_request&X-Amz-Signature=signature";
+        for query in [
+            "x-rustfs-max-total-object-size=1",
+            "X-RustFS-Max-Total-Object-Size=1",
+            "X-Amz-Algorithm=AWS4-HMAC-SHA256&x-rustfs-max-total-object-size=1&x-rustfs-max-total-object-size=2",
+            "X-Amz-Algorithm=AWS4-HMAC-SHA256&x-rustfs-max-total-object-size=-1",
+            "X-Amz-Algorithm=AWS4-HMAC-SHA256&x-rustfs-max-total-object-size=18446744073709551616",
+        ] {
+            assert_eq!(
+                parse_presigned_multipart_max_total_object_size(&headers, Some(query), true)
+                    .unwrap_err()
+                    .code(),
+                &S3ErrorCode::InvalidRequest
+            );
+        }
+
+        let forged = format!("{signed_prefix}&x-rustfs-max-total-object-size=1");
+        assert_eq!(
+            parse_presigned_multipart_max_total_object_size(&headers, Some(&forged), false)
+                .unwrap_err()
+                .code(),
+            &S3ErrorCode::InvalidRequest
+        );
+    }
+
     #[test]
     fn test_credentials_is_expired() {
         let mut cred = create_test_credentials();

rustfs/src/error.rs

@@ -372,6 +372,7 @@ impl From<StorageError> for ApiError {
             StorageError::ObjectExistsAsDirectory(_, _) => S3ErrorCode::InvalidArgument,
             StorageError::InvalidPart(_, _, _) => S3ErrorCode::InvalidPart,
             StorageError::EntityTooSmall(_, _, _) => S3ErrorCode::EntityTooSmall,
+            StorageError::EntityTooLarge(_, _) => S3ErrorCode::EntityTooLarge,
             StorageError::PreconditionFailed => S3ErrorCode::PreconditionFailed,
             StorageError::NotModified => S3ErrorCode::NotModified,
             StorageError::InvalidRangeSpec(_) => S3ErrorCode::InvalidRange,

rustfs/src/storage/access.rs

@@ -16,9 +16,10 @@ use super::ObjectOptions;
 use super::ecfs::FS;
 use super::{ECStore, PolicySys, ReplicationStatusType, StorageError, get_lock_acquire_timeout, is_err_bucket_not_found};
 use crate::auth::{
-    AuthType, RUSTFS_MAX_CONTENT_LENGTH_QUERY, VerifiedPresignedRequest, check_key_valid_with_context,
+    AuthType, RUSTFS_MAX_CONTENT_LENGTH_QUERY, RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY, VerifiedPresignedRequest,
-    get_condition_values_with_client_info, get_condition_values_with_query_and_client_info, get_request_auth_type_with_query,
+    VerifiedSigV4Request, check_key_valid_with_context, get_condition_values_with_client_info,
-    get_session_token, parse_presigned_put_max_content_length,
+    get_condition_values_with_query_and_client_info, get_request_auth_type_with_query, get_session_token,
+    parse_presigned_multipart_max_total_object_size, parse_presigned_put_max_content_length,
 };
 use crate::error::ApiError;
 use crate::license::license_check;
@@ -1771,7 +1772,9 @@ impl S3Access for FS {
 
         // Publish this server's context slot so downstream data-plane handlers
         // resolve the same store (backlog#1052 S6).
-        let verified_presigned = matches!(get_request_auth_type_with_query(cx.headers(), cx.uri().query()), AuthType::Presigned);
+        let auth_type = get_request_auth_type_with_query(cx.headers(), cx.uri().query());
+        let verified_presigned = matches!(auth_type, AuthType::Presigned);
+        let verified_sigv4 = matches!(auth_type, AuthType::Presigned | AuthType::Signed);
         {
             let ext = cx.extensions_mut();
             ext.insert(self.server_ctx().clone());
@@ -1779,6 +1782,9 @@ impl S3Access for FS {
             if verified_presigned {
                 ext.insert(VerifiedPresignedRequest);
             }
+            if verified_sigv4 {
+                ext.insert(VerifiedSigV4Request);
+            }
         }
 
         // The size capability is intentionally scoped to the single-object
@@ -1793,6 +1799,14 @@ impl S3Access for FS {
                 format!("{RUSTFS_MAX_CONTENT_LENGTH_QUERY} is only supported for presigned PutObject"),
             ));
         }
+        if parse_presigned_multipart_max_total_object_size(cx.headers(), cx.uri().query(), verified_sigv4)?.is_some()
+            && cx.s3_op().name() != "CreateMultipartUpload"
+        {
+            return Err(S3Error::with_message(
+                S3ErrorCode::InvalidRequest,
+                format!("{RUSTFS_MAX_TOTAL_OBJECT_SIZE_QUERY} is only supported for CreateMultipartUpload"),
+            ));
+        }
         license_check().map_err(|er| match er.kind() {
             std::io::ErrorKind::PermissionDenied => s3_error!(AccessDenied, "{er}"),
             _ => {