Add the fsnotify hook function to the VFS layer

Signed-off-by: Zhenchen Wang <m202372036@hust.edu.cn>

kernel/src/fs/path/dentry.rs

@@ -265,16 +265,22 @@ impl Dentry {
         };
 
         self.inode.unlink(name)?;
+
+        let nlinks = child_inode.metadata().nlinks;
         fs::notify::on_link_count(&child_inode);
-        if child_inode.metadata().nlinks == 0 {
+        if nlinks == 0 {
             fs::notify::on_inode_removed(&child_inode);
-            let deleted_watches = child_inode.fsnotify_publisher().remove_all_subscribers();
+        }
+        fs::notify::on_delete(self.inode(), &child_inode, || name.to_string());
+        if nlinks == 0 {
+            let publisher = child_inode.fs_event_publisher();
+            publisher.disable_new_subscribers();
+            let removed_nr_subscribers = publisher.remove_all_subscribers();
             child_inode
                 .fs()
-                .fsnotify_info()
-                .remove_subscribers(deleted_watches);
+                .fs_event_subscriber_stats()
+                .remove_subscribers(removed_nr_subscribers);
         }
-        fs::notify::on_delete(self.inode(), &child_inode, String::from(name));
         Ok(())
     }
 
@@ -310,15 +316,21 @@ impl Dentry {
         };
 
         self.inode.rmdir(name)?;
-        if child_inode.metadata().nlinks == 0 {
+
+        let nlinks = child_inode.metadata().nlinks;
+        if nlinks == 0 {
             fs::notify::on_inode_removed(&child_inode);
-            let deleted_watches = child_inode.fsnotify_publisher().remove_all_subscribers();
+        }
+        fs::notify::on_delete(self.inode(), &child_inode, || name.to_string());
+        if nlinks == 0 {
+            let publisher = child_inode.fs_event_publisher();
+            publisher.disable_new_subscribers();
+            let removed_nr_subscribers = publisher.remove_all_subscribers();
             child_inode
                 .fs()
-                .fsnotify_info()
-                .remove_subscribers(deleted_watches);
+                .fs_event_subscriber_stats()
+                .remove_subscribers(removed_nr_subscribers);
         }
-        fs::notify::on_delete(self.inode(), &child_inode, String::from(name));
         Ok(())
     }
 

kernel/src/syscall/chmod.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::{get_file_fast, FileDesc},
         fs_resolver::{FsPath, AT_FDCWD},
@@ -16,6 +17,9 @@ pub fn sys_fchmod(fd: FileDesc, mode: u16, ctx: &Context) -> Result<SyscallRetur
     let mut file_table = ctx.thread_local.borrow_file_table_mut();
     let file = get_file_fast!(&mut file_table, fd);
     file.inode().set_mode(InodeMode::from_bits_truncate(mode))?;
+    if let Some(path) = file.path() {
+        fs::notify::on_attr_change(path);
+    }
     Ok(SyscallReturn::Return(0))
 }
 
@@ -46,9 +50,11 @@ pub fn sys_fchmodat(
             .read()
             .lookup_inode(&fs_path)?
     };
-
     path_or_inode
         .inode()
         .set_mode(InodeMode::from_bits_truncate(mode))?;
+    if let Some(path) = path_or_inode.into_path() {
+        fs::notify::on_attr_change(&path);
+    }
     Ok(SyscallReturn::Return(0))
 }

kernel/src/syscall/close.rs

@@ -4,6 +4,7 @@ use bitflags::bitflags;
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{FdFlags, FileDesc},
     prelude::*,
     process::ContextUnshareAdminApi,
@@ -26,6 +27,8 @@ pub fn sys_close(fd: FileDesc, ctx: &Context) -> Result<SyscallReturn> {
         file_table_locked.close_file(fd).unwrap()
     };
 
+    fs::notify::on_close(&file);
+
     // Cleanup work needs to be done in the `Drop` impl.
     //
     // We don't mind the races between closing the file descriptor and using the file descriptor,

kernel/src/syscall/fallocate.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::{get_file_fast, FileDesc},
         utils::FallocMode,
@@ -33,6 +34,7 @@ pub fn sys_fallocate(
     )?;
     file.fallocate(falloc_mode, offset as usize, len as usize)?;
 
+    fs::notify::on_modify(&file);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/getdents64.rs

@@ -4,6 +4,7 @@ use core::marker::PhantomData;
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::{get_file_fast, FileDesc},
         utils::{DirentVisitor, InodeType},
@@ -34,6 +35,7 @@ pub fn sys_getdents(
     let read_len = reader.read_len();
     ctx.user_space()
         .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+    fs::notify::on_access(&file);
     Ok(SyscallReturn::Return(read_len as _))
 }
 
@@ -60,6 +62,7 @@ pub fn sys_getdents64(
     let read_len = reader.read_len();
     ctx.user_space()
         .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+    fs::notify::on_access(&file);
     Ok(SyscallReturn::Return(read_len as _))
 }
 

kernel/src/syscall/mkdir.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::FileDesc,
         fs_resolver::{FsPath, AT_FDCWD},
@@ -35,7 +36,8 @@ pub fn sys_mkdirat(
         let mask_mode = mode & !fs_ref.umask().get();
         InodeMode::from_bits_truncate(mask_mode)
     };
-    let _ = dir_path.new_fs_child(&name, InodeType::Dir, inode_mode)?;
+    dir_path.new_fs_child(&name, InodeType::Dir, inode_mode)?;
+    fs::notify::on_mkdir(&dir_path, name);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/mknod.rs

@@ -5,6 +5,7 @@ use device_id::DeviceId;
 use super::SyscallReturn;
 use crate::{
     device::get_device,
+    fs,
     fs::{
         file_table::FileDesc,
         fs_resolver::{FsPath, AT_FDCWD},
@@ -59,7 +60,7 @@ pub fn sys_mknodat(
         }
         _ => return_errno_with_message!(Errno::EPERM, "unimplemented file types"),
     }
-
+    fs::notify::on_create(&dir_path, name);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/open.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_handle::FileLike,
         file_table::{FdFlags, FileDesc},
@@ -56,9 +57,10 @@ pub fn sys_openat(
             } else {
                 FdFlags::empty()
             };
-        file_table_locked.insert(file_handle, fd_flags)
+        file_table_locked.insert(file_handle.clone(), fd_flags)
     };
-
+    let file_like: Arc<dyn FileLike> = file_handle;
+    fs::notify::on_open(&file_like);
     Ok(SyscallReturn::Return(fd as _))
 }
 
@@ -122,6 +124,7 @@ fn do_open(
             let (parent, tail_name) = result.into_parent_and_basename();
             let new_path =
                 parent.new_fs_child(&tail_name, InodeType::File, open_args.inode_mode)?;
+            fs::notify::on_create(&parent, tail_name.clone());
 
             // Don't check access mode for newly created file.
             Arc::new(InodeHandle::new_unchecked_access(

kernel/src/syscall/pread64.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
 };
@@ -39,5 +40,9 @@ pub fn sys_pread64(
         file.read_at(offset as usize, &mut writer)?
     };
 
+    if read_len > 0 {
+        fs::notify::on_access(&file);
+    }
+
     Ok(SyscallReturn::Return(read_len as _))
 }

kernel/src/syscall/preadv.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
     util::VmWriterArray,
@@ -110,6 +111,10 @@ fn do_sys_preadv(
         }
     }
 
+    if total_len > 0 {
+        fs::notify::on_access(&file);
+    }
+
     Ok(total_len)
 }
 
@@ -155,6 +160,10 @@ fn do_sys_readv(
         }
     }
 
+    if total_len > 0 {
+        fs::notify::on_access(&file);
+    }
+
     Ok(total_len)
 }
 

kernel/src/syscall/pwrite64.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
 };
@@ -36,5 +37,10 @@ pub fn sys_pwrite64(
     let user_space = ctx.user_space();
     let mut reader = user_space.reader(user_buf_ptr, user_buf_len)?;
     let write_len = file.write_at(offset as _, &mut reader)?;
+
+    if write_len > 0 {
+        fs::notify::on_modify(&file);
+    }
+
     Ok(SyscallReturn::Return(write_len as _))
 }

kernel/src/syscall/pwritev.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
     util::VmReaderArray,
@@ -111,6 +112,10 @@ fn do_sys_pwritev(
             break;
         }
     }
+    if total_len > 0 {
+        fs::notify::on_modify(&file);
+    }
+
     Ok(total_len)
 }
 
@@ -151,6 +156,10 @@ fn do_sys_writev(
             break;
         }
     }
+    if total_len > 0 {
+        fs::notify::on_modify(&file);
+    }
+
     Ok(total_len)
 }
 

kernel/src/syscall/read.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
 };
@@ -37,5 +38,8 @@ pub fn sys_read(
         _ => err,
     })?;
 
+    if read_len > 0 {
+        fs::notify::on_access(&file);
+    }
     Ok(SyscallReturn::Return(read_len as _))
 }

kernel/src/syscall/removexattr.rs

@@ -8,6 +8,7 @@ use super::{
     SyscallReturn,
 };
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
     syscall::constants::MAX_FILENAME_LEN,
@@ -52,6 +53,12 @@ fn removexattr(
     let xattr_name = parse_xattr_name(name_str.as_ref())?;
     check_xattr_namespace(xattr_name.namespace(), ctx)?;
 
-    let path = lookup_path_for_xattr(&file_ctx, ctx)?;
-    path.remove_xattr(xattr_name)
+    match lookup_path_for_xattr(&file_ctx, ctx) {
+        Ok(path) => {
+            path.remove_xattr(xattr_name)?;
+            fs::notify::on_attr_change(&path);
+            Ok(())
+        }
+        Err(e) => Err(e),
+    }
 }

kernel/src/syscall/sendfile.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{FileDesc, WithFileTable},
     prelude::*,
 };
@@ -117,5 +118,8 @@ pub fn sys_sendfile(
         ctx.user_space().write_val(offset_ptr, &(offset as isize))?;
     }
 
+    fs::notify::on_access(&in_file);
+    fs::notify::on_modify(&out_file);
+
     Ok(SyscallReturn::Return(total_len as _))
 }

kernel/src/syscall/setxattr.rs

@@ -4,6 +4,7 @@ use alloc::borrow::Cow;
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_handle::FileLike,
         file_table::{get_file_fast, FileDesc},
@@ -114,7 +115,9 @@ fn setxattr(
     let mut value_reader = user_space.reader(value_ptr, value_len)?;
 
     let path = lookup_path_for_xattr(&file_ctx, ctx)?;
-    path.set_xattr(xattr_name, &mut value_reader, flags)
+    path.set_xattr(xattr_name, &mut value_reader, flags)?;
+    fs::notify::on_attr_change(&path);
+    Ok(())
 }
 
 /// The context to describe the target file for xattr operations.

kernel/src/syscall/symlink.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::FileDesc,
         fs_resolver::{FsPath, AT_FDCWD},
@@ -43,6 +44,7 @@ pub fn sys_symlinkat(
 
     let new_path = dir_path.new_fs_child(&link_name, InodeType::SymLink, mkmod!(a+rwx))?;
     new_path.inode().write_link(&target)?;
+    fs::notify::on_create(&dir_path, link_name);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/truncate.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::{
         file_table::{get_file_fast, FileDesc},
         fs_resolver::{FsPath, AT_FDCWD},
@@ -19,6 +20,9 @@ pub fn sys_ftruncate(fd: FileDesc, len: isize, ctx: &Context) -> Result<SyscallR
     let mut file_table = ctx.thread_local.borrow_file_table_mut();
     let file = get_file_fast!(&mut file_table, fd);
     file.resize(len as usize)?;
+    if let Some(path) = file.path() {
+        fs::notify::on_change(path);
+    }
     Ok(SyscallReturn::Return(0))
 }
 
@@ -38,6 +42,7 @@ pub fn sys_truncate(path_ptr: Vaddr, len: isize, ctx: &Context) -> Result<Syscal
             .lookup(&fs_path)?
     };
     dir_path.resize(len as usize)?;
+    fs::notify::on_change(&dir_path);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/utimens.rs

@@ -4,6 +4,7 @@ use core::time::Duration;
 
 use super::{constants::MAX_FILENAME_LEN, SyscallReturn};
 use crate::{
+    fs,
     fs::{
         file_table::FileDesc,
         fs_resolver::{FsPath, AT_FDCWD},
@@ -142,7 +143,7 @@ fn vfs_utimes(path: &Path, times: Option<TimeSpecPair>) -> Result<SyscallReturn>
     path.set_atime(atime);
     path.set_mtime(mtime);
     path.set_ctime(ctime);
-
+    fs::notify::on_attr_change(path);
     Ok(SyscallReturn::Return(0))
 }
 

kernel/src/syscall/write.rs

@@ -2,6 +2,7 @@
 
 use super::SyscallReturn;
 use crate::{
+    fs,
     fs::file_table::{get_file_fast, FileDesc},
     prelude::*,
 };
@@ -37,5 +38,8 @@ pub fn sys_write(
         _ => err,
     })?;
 
+    if write_len > 0 {
+        fs::notify::on_modify(&file);
+    }
     Ok(SyscallReturn::Return(write_len as _))
 }