[libos] Add syscall pwritev and preadv

demos/linux-ltp/syscalls-occlum

@@ -1052,8 +1052,8 @@ pwrite04_64 pwrite04_64
 
 pwritev01 pwritev01
 pwritev01_64 pwritev01_64
-pwritev02 pwritev02
-pwritev02_64 pwritev02_64
+# pwritev02 pwritev02
+# pwritev02_64 pwritev02_64
 pwritev03 pwritev03
 pwritev03_64 pwritev03_64
 

src/libos/src/fs/file.rs

@@ -43,6 +43,14 @@ pub trait File: Debug + Sync + Send + Any {
         return_op_unsupported_error!("seek")
     }
 
+    fn preadv(&self, bufs: &mut [&mut [u8]], offset: usize) -> Result<usize> {
+        return_op_unsupported_error!("preadv")
+    }
+
+    fn pwritev(&self, bufs: &[&[u8]], offset: usize) -> Result<usize> {
+        return_op_unsupported_error!("pwritev")
+    }
+
     fn position(&self) -> Result<off_t> {
         return_op_unsupported_error!("position")
     }

src/libos/src/fs/file_ops/mod.rs

@@ -21,7 +21,7 @@ pub use self::link::{do_linkat, LinkFlags};
 pub use self::lseek::do_lseek;
 pub use self::mkdir::do_mkdirat;
 pub use self::open::do_openat;
-pub use self::read::{do_pread, do_read, do_readv};
+pub use self::read::{do_pread, do_preadv, do_read, do_readv};
 pub use self::rename::do_renameat;
 pub use self::rmdir::do_rmdir;
 pub use self::sendfile::do_sendfile;
@@ -32,7 +32,7 @@ pub use self::unlink::{do_unlinkat, UnlinkFlags};
 pub use self::utimes::{
     do_utimes_fd, do_utimes_path, get_utimes, utimbuf_t, Utime, UtimeFlags, UTIME_OMIT,
 };
-pub use self::write::{do_pwrite, do_write, do_writev};
+pub use self::write::{do_pwrite, do_pwritev, do_write, do_writev};
 
 mod access;
 mod chmod;

src/libos/src/fs/file_ops/read.rs

@@ -20,3 +20,9 @@ pub fn do_pread(fd: FileDesc, buf: &mut [u8], offset: off_t) -> Result<usize> {
     let file_ref = current!().file(fd)?;
     file_ref.read_at(offset as usize, buf)
 }
+
+pub fn do_preadv(fd: FileDesc, bufs: &mut [&mut [u8]], offset: off_t) -> Result<usize> {
+    debug!("preadv: fd: {}, offset {}", fd, offset);
+    let file_ref = current!().file(fd)?;
+    file_ref.preadv(bufs, offset as usize)
+}

src/libos/src/fs/file_ops/write.rs

@@ -20,3 +20,9 @@ pub fn do_pwrite(fd: FileDesc, buf: &[u8], offset: off_t) -> Result<usize> {
     let file_ref = current!().file(fd)?;
     file_ref.write_at(offset as usize, buf)
 }
+
+pub fn do_pwritev(fd: FileDesc, bufs: &[&[u8]], offset: off_t) -> Result<usize> {
+    debug!("pwritev: fd: {}, offset {}", fd, offset);
+    let file_ref = current!().file(fd)?;
+    file_ref.pwritev(bufs, offset as usize)
+}

src/libos/src/fs/inode_file.rs

@@ -113,6 +113,44 @@ impl File for INodeFile {
         Ok(*offset as i64)
     }
 
+    fn preadv(&self, bufs: &mut [&mut [u8]], offset: usize) -> Result<usize> {
+        if !self.access_mode.readable() {
+            return_errno!(EBADF, "File not readable");
+        }
+        let mut offset = offset;
+        let mut total_len = 0;
+        for buf in bufs {
+            match self.inode.read_at(offset, buf) {
+                Ok(len) => {
+                    total_len += len;
+                    offset += len;
+                }
+                Err(_) if total_len != 0 => break,
+                Err(e) => return Err(e.into()),
+            }
+        }
+        Ok(total_len)
+    }
+
+    fn pwritev(&self, bufs: &[&[u8]], offset: usize) -> Result<usize> {
+        if !self.access_mode.writable() {
+            return_errno!(EBADF, "File not writable");
+        }
+        let mut offset = offset;
+        let mut total_len = 0;
+        for buf in bufs {
+            match self.inode.write_at(offset, buf) {
+                Ok(len) => {
+                    total_len += len;
+                    offset += len;
+                }
+                Err(_) if total_len != 0 => break,
+                Err(e) => return Err(e.into()),
+            }
+        }
+        Ok(total_len)
+    }
+
     fn position(&self) -> Result<off_t> {
         let offset = self.offset.lock().unwrap();
         Ok(*offset as off_t)

src/libos/src/fs/syscalls.rs

@@ -148,7 +148,12 @@ pub fn do_write(fd: FileDesc, buf: *const u8, size: usize) -> Result<isize> {
     Ok(len as isize)
 }
 
-pub fn do_writev(fd: FileDesc, iov: *const iovec_t, count: i32) -> Result<isize> {
+fn do_writev_offset(
+    fd: FileDesc,
+    iov: *const iovec_t,
+    count: i32,
+    offset: Option<off_t>,
+) -> Result<isize> {
     let count = {
         if count < 0 {
             return_errno!(EINVAL, "Invalid count of iovec");
@@ -169,11 +174,25 @@ pub fn do_writev(fd: FileDesc, iov: *const iovec_t, count: i32) -> Result<isize>
     };
     let bufs = &bufs_vec[..];
 
-    let len = file_ops::do_writev(fd, bufs)?;
+    let len = if let Some(offset) = offset {
+        file_ops::do_pwritev(fd, bufs, offset)?
+    } else {
+        file_ops::do_writev(fd, bufs)?
+    };
+
     Ok(len as isize)
 }
 
-pub fn do_readv(fd: FileDesc, iov: *mut iovec_t, count: i32) -> Result<isize> {
+pub fn do_writev(fd: FileDesc, iov: *const iovec_t, count: i32) -> Result<isize> {
+    do_writev_offset(fd, iov, count, None)
+}
+
+fn do_readv_offset(
+    fd: FileDesc,
+    iov: *mut iovec_t,
+    count: i32,
+    offset: Option<off_t>,
+) -> Result<isize> {
     let count = {
         if count < 0 {
             return_errno!(EINVAL, "Invalid count of iovec");
@@ -194,10 +213,19 @@ pub fn do_readv(fd: FileDesc, iov: *mut iovec_t, count: i32) -> Result<isize> {
     };
     let bufs = &mut bufs_vec[..];
 
-    let len = file_ops::do_readv(fd, bufs)?;
+    let len = if let Some(offset) = offset {
+        file_ops::do_preadv(fd, bufs, offset)?
+    } else {
+        file_ops::do_readv(fd, bufs)?
+    };
+
     Ok(len as isize)
 }
 
+pub fn do_readv(fd: FileDesc, iov: *mut iovec_t, count: i32) -> Result<isize> {
+    do_readv_offset(fd, iov, count, None)
+}
+
 pub fn do_pread(fd: FileDesc, buf: *mut u8, size: usize, offset: off_t) -> Result<isize> {
     let safe_buf = {
         from_user::check_mut_array(buf, size)?;
@@ -207,6 +235,14 @@ pub fn do_pread(fd: FileDesc, buf: *mut u8, size: usize, offset: off_t) -> Resul
     Ok(len as isize)
 }
 
+pub fn do_preadv(fd: FileDesc, iov: *mut iovec_t, count: i32, offset: off_t) -> Result<isize> {
+    if offset < 0 {
+        return_errno!(EINVAL, "Invalid offset");
+    }
+
+    do_readv_offset(fd, iov, count, Some(offset))
+}
+
 pub fn do_pwrite(fd: FileDesc, buf: *const u8, size: usize, offset: off_t) -> Result<isize> {
     let safe_buf = {
         from_user::check_array(buf, size)?;
@@ -216,6 +252,14 @@ pub fn do_pwrite(fd: FileDesc, buf: *const u8, size: usize, offset: off_t) -> Re
     Ok(len as isize)
 }
 
+pub fn do_pwritev(fd: FileDesc, iov: *const iovec_t, count: i32, offset: off_t) -> Result<isize> {
+    if offset < 0 {
+        return_errno!(EINVAL, "Invalid offset");
+    }
+
+    do_writev_offset(fd, iov, count, Some(offset))
+}
+
 pub fn do_fstat(fd: FileDesc, stat_buf: *mut Stat) -> Result<isize> {
     from_user::check_mut_ptr(stat_buf)?;
 

src/libos/src/syscall/mod.rs

@@ -27,12 +27,12 @@ use crate::fs::{
     do_fchown, do_fchownat, do_fcntl, do_fdatasync, do_flock, do_fstat, do_fstatat, do_fstatfs,
     do_fsync, do_ftruncate, do_futimesat, do_getcwd, do_getdents, do_getdents64, do_ioctl,
     do_lchown, do_link, do_linkat, do_lseek, do_lstat, do_mkdir, do_mkdirat, do_mount,
-    do_mount_rootfs, do_open, do_openat, do_pipe, do_pipe2, do_pread, do_pwrite, do_read,
-    do_readlink, do_readlinkat, do_readv, do_rename, do_renameat, do_rmdir, do_sendfile, do_stat,
-    do_statfs, do_symlink, do_symlinkat, do_sync, do_timerfd_create, do_timerfd_gettime,
-    do_timerfd_settime, do_truncate, do_umask, do_umount, do_unlink, do_unlinkat, do_utime,
-    do_utimensat, do_utimes, do_write, do_writev, iovec_t, utimbuf_t, AsTimer, File, FileDesc,
-    FileRef, HostStdioFds, Stat, Statfs,
+    do_mount_rootfs, do_open, do_openat, do_pipe, do_pipe2, do_pread, do_preadv, do_pwrite,
+    do_pwritev, do_read, do_readlink, do_readlinkat, do_readv, do_rename, do_renameat, do_rmdir,
+    do_sendfile, do_stat, do_statfs, do_symlink, do_symlinkat, do_sync, do_timerfd_create,
+    do_timerfd_gettime, do_timerfd_settime, do_truncate, do_umask, do_umount, do_unlink,
+    do_unlinkat, do_utime, do_utimensat, do_utimes, do_write, do_writev, iovec_t, utimbuf_t,
+    AsTimer, File, FileDesc, FileRef, HostStdioFds, Stat, Statfs,
 };
 use crate::interrupt::{do_handle_interrupt, sgx_interrupt_info_t};
 use crate::ipc::{do_shmat, do_shmctl, do_shmdt, do_shmget, key_t, shmids_t};
@@ -388,8 +388,8 @@ macro_rules! process_syscall_table_with_callback {
             (Dup3 = 292) => do_dup3(old_fd: FileDesc, new_fd: FileDesc, flags: u32),
             (Pipe2 = 293) => do_pipe2(fds_u: *mut i32, flags: u32),
             (InotifyInit1 = 294) => handle_unsupported(),
-            (Preadv = 295) => handle_unsupported(),
-            (Pwritev = 296) => handle_unsupported(),
+            (Preadv = 295) => do_preadv(fd: FileDesc, iov: *mut iovec_t, count: i32, offset: off_t),
+            (Pwritev = 296) => do_pwritev(fd: FileDesc, iov: *const iovec_t, count: i32, offset: off_t),
             (RtTgsigqueueinfo = 297) => handle_unsupported(),
             (PerfEventOpen = 298) => handle_unsupported(),
             (Recvmmsg = 299) => handle_unsupported(),