diff --git a/backend/posix/posix.go b/backend/posix/posix.go
index ca14dde8..304c0716 100644
--- a/backend/posix/posix.go
+++ b/backend/posix/posix.go
@@ -79,6 +79,9 @@ const (
 	bucketLockKey       = "bucket-lock"
 	objectRetentionKey  = "object-retention"
 	objectLegalHoldKey  = "object-legal-hold"
+
+	doFalloc   = true
+	skipFalloc = false
 )
 
 type PosixOpts struct {
@@ -461,7 +464,7 @@ func (p *Posix) CompleteMultipartUpload(ctx context.Context, input *s3.CompleteM
 	}
 
 	f, err := p.openTmpFile(filepath.Join(bucket, metaTmpDir), bucket, object,
-		totalsize, acct)
+		totalsize, acct, skipFalloc)
 	if err != nil {
 		if errors.Is(err, syscall.EDQUOT) {
 			return nil, s3err.GetAPIError(s3err.ErrQuotaExceeded)
@@ -477,7 +480,7 @@ func (p *Posix) CompleteMultipartUpload(ctx context.Context, input *s3.CompleteM
 		if err != nil {
 			return nil, fmt.Errorf("open part %v: %v", *part.PartNumber, err)
 		}
-		_, err = io.Copy(f, pf)
+		_, err = io.Copy(f.File(), pf)
 		pf.Close()
 		if err != nil {
 			if errors.Is(err, syscall.EDQUOT) {
@@ -970,7 +973,7 @@ func (p *Posix) UploadPart(ctx context.Context, input *s3.UploadPartInput) (stri
 	partPath := filepath.Join(objdir, uploadID, fmt.Sprintf("%v", *part))
 
 	f, err := p.openTmpFile(filepath.Join(bucket, objdir),
-		bucket, partPath, length, acct)
+		bucket, partPath, length, acct, doFalloc)
 	if err != nil {
 		if errors.Is(err, syscall.EDQUOT) {
 			return "", s3err.GetAPIError(s3err.ErrQuotaExceeded)
@@ -1078,7 +1081,7 @@ func (p *Posix) UploadPartCopy(ctx context.Context, upi *s3.UploadPartCopyInput)
 	}
 
 	f, err := p.openTmpFile(filepath.Join(*upi.Bucket, objdir),
-		*upi.Bucket, partPath, length, acct)
+		*upi.Bucket, partPath, length, acct, doFalloc)
 	if err != nil {
 		if errors.Is(err, syscall.EDQUOT) {
 			return s3response.CopyObjectResult{}, s3err.GetAPIError(s3err.ErrQuotaExceeded)
@@ -1217,7 +1220,7 @@ func (p *Posix) PutObject(ctx context.Context, po *s3.PutObjectInput) (string, e
 	}
 
 	f, err := p.openTmpFile(filepath.Join(*po.Bucket, metaTmpDir),
-		*po.Bucket, *po.Key, contentLength, acct)
+		*po.Bucket, *po.Key, contentLength, acct, doFalloc)
 	if err != nil {
 		if errors.Is(err, syscall.EDQUOT) {
 			return "", s3err.GetAPIError(s3err.ErrQuotaExceeded)
diff --git a/backend/posix/with_otmpfile.go b/backend/posix/with_otmpfile.go
index a772800a..fc49827f 100644
--- a/backend/posix/with_otmpfile.go
+++ b/backend/posix/with_otmpfile.go
@@ -50,7 +50,7 @@ var (
 	defaultFilePerm uint32 = 0644
 )
 
-func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Account) (*tmpfile, error) {
+func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Account, dofalloc bool) (*tmpfile, error) {
 	uid, gid, doChown := p.getChownIDs(acct)
 
 	// O_TMPFILE allows for a file handle to an unnamed file in the filesystem.
@@ -81,7 +81,7 @@ func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Accou
 			gid:        gid,
 		}
 		// falloc is best effort, its fine if this fails
-		if size > 0 {
+		if size > 0 && dofalloc {
 			tmp.falloc()
 		}
 
@@ -111,7 +111,7 @@ func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Accou
 	}
 
 	// falloc is best effort, its fine if this fails
-	if size > 0 {
+	if size > 0 && dofalloc {
 		tmp.falloc()
 	}
 
@@ -221,3 +221,7 @@ func (tmp *tmpfile) Write(b []byte) (int, error) {
 func (tmp *tmpfile) cleanup() {
 	tmp.f.Close()
 }
+
+func (tmp *tmpfile) File() *os.File {
+	return tmp.f
+}
diff --git a/backend/posix/without_otmpfile.go b/backend/posix/without_otmpfile.go
index d6d41944..717f3c6c 100644
--- a/backend/posix/without_otmpfile.go
+++ b/backend/posix/without_otmpfile.go
@@ -36,7 +36,7 @@ type tmpfile struct {
 	size    int64
 }
 
-func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Account) (*tmpfile, error) {
+func (p *Posix) openTmpFile(dir, bucket, obj string, size int64, acct auth.Account, _ bool) (*tmpfile, error) {
 	uid, gid, doChown := p.getChownIDs(acct)
 
 	// Create a temp file for upload while in progress (see link comments below).
@@ -112,3 +112,7 @@ func (tmp *tmpfile) Write(b []byte) (int, error) {
 func (tmp *tmpfile) cleanup() {
 	tmp.f.Close()
 }
+
+func (tmp *tmpfile) File() *os.File {
+	return tmp.f
+}