From 4dbea1f298c99736b1e8f77669d10e4ab651da23 Mon Sep 17 00:00:00 2001
From: ethan <chenjie4255@gmail.com>
Date: Thu, 5 Feb 2026 08:15:22 +0800
Subject: [PATCH] dll & fuse: Added "AddWriteEaPerm" mount option.

---
 src/dll/fuse/fuse.c      |  3 +++
 src/dll/fuse/fuse_intf.c | 39 ++++++++++++++++++++++++++++++++++++++-
 src/dll/fuse/library.h   |  2 ++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/dll/fuse/fuse.c b/src/dll/fuse/fuse.c
index dae28a0f..2f63351a 100644
--- a/src/dll/fuse/fuse.c
+++ b/src/dll/fuse/fuse.c
@@ -119,6 +119,8 @@ static struct fuse_opt fsp_fuse_core_opts[] =
     FUSE_OPT_KEY("GroupName=", 'g'),
     FSP_FUSE_CORE_OPT("--GroupName=", set_gid, 1),
     FUSE_OPT_KEY("--GroupName=", 'g'),
+    
+    FSP_FUSE_CORE_OPT("AddWriteEaAccess", add_write_ea_access, 1),
 
     FUSE_OPT_END,
 };
@@ -902,6 +904,7 @@ FSP_FUSE_API struct fuse *fsp_fuse_new(struct fsp_fuse_env *env,
     f->set_create_dir_umask = opt_data.set_create_dir_umask; f->create_dir_umask = opt_data.create_dir_umask;
     f->set_uid = opt_data.set_uid; f->uid = opt_data.uid;
     f->set_gid = opt_data.set_gid; f->gid = opt_data.gid;
+    f->add_write_ea_access = opt_data.add_write_ea_access;
     f->rellinks = opt_data.rellinks;
     f->dothidden = opt_data.dothidden;
     f->ThreadCount = opt_data.ThreadCount;
diff --git a/src/dll/fuse/fuse_intf.c b/src/dll/fuse/fuse_intf.c
index 37acd0fa..73d60ce7 100644
--- a/src/dll/fuse/fuse_intf.c
+++ b/src/dll/fuse/fuse_intf.c
@@ -545,6 +545,39 @@ static NTSTATUS fsp_fuse_intf_GetFileInfoFunnel(FSP_FILE_SYSTEM *FileSystem,
     return STATUS_SUCCESS;
 }
 
+static VOID fsp_fuse_intf_AddWriteEaAccess(
+    PSECURITY_DESCRIPTOR SecurityDescriptor)
+{
+    BOOL DaclPresent, DaclDefaulted;
+    PACL Acl;
+    ACL_SIZE_INFORMATION AclSizeInfo;
+    PACE_HEADER Ace;
+    PACCESS_MASK AccessMask;
+
+    if (!GetSecurityDescriptorDacl(SecurityDescriptor, &DaclPresent, &Acl, &DaclDefaulted))
+        return;
+    if (0 == Acl)
+        return;
+    if (!GetAclInformation(Acl, &AclSizeInfo, sizeof AclSizeInfo, AclSizeInformation))
+        return;
+
+    for (DWORD I = 0; I < AclSizeInfo.AceCount; I++)
+    {
+        if (!GetAce(Acl, I, &Ace))
+            return;
+
+        if (Ace->AceType == ACCESS_ALLOWED_ACE_TYPE)
+            AccessMask = &((PACCESS_ALLOWED_ACE)Ace)->Mask;
+        else if (Ace->AceType == ACCESS_DENIED_ACE_TYPE)
+            AccessMask = &((PACCESS_DENIED_ACE)Ace)->Mask;
+        else
+            continue;
+
+        if (*AccessMask & FILE_WRITE_DATA)
+            *AccessMask |= FILE_WRITE_EA;
+    }
+}
+
 static NTSTATUS fsp_fuse_intf_GetSecurityEx(FSP_FILE_SYSTEM *FileSystem,
     const char *PosixPath, struct fuse_file_info *fi,
     PUINT32 PFileAttributes,
@@ -578,8 +611,12 @@ static NTSTATUS fsp_fuse_intf_GetSecurityEx(FSP_FILE_SYSTEM *FileSystem,
         }
 
         *PSecurityDescriptorSize = SecurityDescriptorSize;
-        if (0 != SecurityDescriptorBuf)
+        if (0 != SecurityDescriptorBuf) 
+        {
             memcpy(SecurityDescriptorBuf, SecurityDescriptor, SecurityDescriptorSize);
+            if (f->add_write_ea_access)
+                fsp_fuse_intf_AddWriteEaAccess(SecurityDescriptorBuf);
+        }
     }
 
     if (0 != PFileAttributes)
diff --git a/src/dll/fuse/library.h b/src/dll/fuse/library.h
index dc981225..d9185188 100644
--- a/src/dll/fuse/library.h
+++ b/src/dll/fuse/library.h
@@ -55,6 +55,7 @@ struct fuse
     int set_create_dir_umask, create_dir_umask;
     int set_uid, uid;
     int set_gid, gid;
+    int add_write_ea_access;
     int rellinks;
     int dothidden;
     unsigned ThreadCount;
@@ -147,6 +148,7 @@ struct fsp_fuse_core_opt_data
         set_create_dir_umask, create_dir_umask,
         set_uid, uid, username_to_uid_result,
         set_gid, gid,
+        add_write_ea_access,
         set_uidmap,
         set_attr_timeout, attr_timeout,
         rellinks,