Add posix_fallocate

deps/sefs

@@ -1 +1 @@
-Subproject commit 88784548d5db1156f2d9e71f968d0d78fa7957db
+Subproject commit bb574e0c0bb0a3034f1f4eb48b1d559fe84d2555

src/libos/src/error/to_errno.rs

@@ -96,6 +96,7 @@ impl ToErrno for rcore_fs::vfs::FsError {
             FsError::NoIntegrity => EIO,
             FsError::PermError => EPERM,
             FsError::NameTooLong => ENAMETOOLONG,
+            FsError::FileTooBig => EFBIG,
         }
     }
 }

src/libos/src/fs/file.rs

@@ -91,6 +91,10 @@ pub trait File: Debug + Sync + Send + Any {
         return_op_unsupported_error!("set_advisory_lock")
     }
 
+    fn fallocate(&self, _mode: u32, _offset: u64, _len: u64) -> Result<()> {
+        return_op_unsupported_error!("fallocate")
+    }
+
     // TODO: remove this function after all users of this code are removed
     fn poll(&self) -> Result<(crate::net::PollEventFlags)> {
         return_op_unsupported_error!("poll")

src/libos/src/fs/file_ops/fallocate.rs

@@ -0,0 +1,11 @@
+use super::*;
+
+pub fn do_fallocate(fd: FileDesc, mode: u32, offset: u64, len: u64) -> Result<()> {
+    debug!(
+        "fallocate: fd: {}, mode: {}, offset: {}, len: {}",
+        fd, mode, offset, len
+    );
+    let file_ref = current!().file(fd)?;
+    file_ref.fallocate(mode, offset, len)?;
+    Ok(())
+}

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

@@ -7,6 +7,7 @@ pub use self::chown::{do_fchown, do_fchownat, ChownFlags};
 pub use self::close::do_close;
 pub use self::dirent::{do_getdents, do_getdents64};
 pub use self::dup::{do_dup, do_dup2, do_dup3};
+pub use self::fallocate::do_fallocate;
 pub use self::fcntl::{do_fcntl, FcntlCmd};
 pub use self::file_flags::{AccessMode, CreationFlags, StatusFlags};
 pub use self::flock::{Flock, FlockType};
@@ -36,6 +37,7 @@ mod chown;
 mod close;
 mod dirent;
 mod dup;
+mod fallocate;
 mod fcntl;
 mod file_flags;
 mod flock;

src/libos/src/fs/inode_file.rs

@@ -121,6 +121,11 @@ impl File for INodeFile {
         Ok(())
     }
 
+    fn fallocate(&self, mode: u32, offset: u64, len: u64) -> Result<()> {
+        self.inode.fallocate(mode, offset, len)?;
+        Ok(())
+    }
+
     fn set_len(&self, len: u64) -> Result<()> {
         if !self.access_mode.writable() {
             return_errno!(EACCES, "File not writable. Can't set len.");

src/libos/src/fs/syscalls.rs

@@ -537,3 +537,19 @@ pub fn do_mount_rootfs(
     fs_ops::do_mount_rootfs(&user_config, &key)?;
     Ok(0)
 }
+
+pub fn do_fallocate(fd: FileDesc, mode: u32, offset: off_t, len: off_t) -> Result<isize> {
+    if offset < 0 || len <= 0 {
+        return_errno!(
+            EINVAL,
+            "offset was less than 0, or len was less than or equal to 0"
+        );
+    }
+    // Current implementation is just the posix_fallocate
+    // TODO: Support more modes in fallocate
+    if mode != 0 {
+        return_errno!(ENOSYS, "unsupported mode");
+    }
+    file_ops::do_fallocate(fd, mode, offset as u64, len as u64)?;
+    Ok(0)
+}

src/libos/src/syscall/mod.rs

@@ -23,8 +23,8 @@ use util::mem_util::from_user::*;
 use crate::exception::do_handle_exception;
 use crate::fs::{
     do_access, do_chdir, do_chmod, do_chown, do_close, do_dup, do_dup2, do_dup3, do_eventfd,
-    do_eventfd2, do_faccessat, do_fchmod, do_fchmodat, do_fchown, do_fchownat, do_fcntl,
+    do_eventfd2, do_faccessat, do_fallocate, do_fchmod, do_fchmodat, do_fchown, do_fchownat,
-    do_fdatasync, do_fstat, do_fstatat, do_fsync, do_ftruncate, do_getcwd, do_getdents,
+    do_fcntl, do_fdatasync, do_fstat, do_fstatat, do_fsync, do_ftruncate, do_getcwd, do_getdents,
     do_getdents64, do_ioctl, do_lchown, do_link, do_linkat, do_lseek, do_lstat, do_mkdir,
     do_mkdirat, 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,
@@ -369,7 +369,7 @@ macro_rules! process_syscall_table_with_callback {
             (Signalfd = 282) => handle_unsupported(),
             (TimerfdCreate = 283) => handle_unsupported(),
             (Eventfd = 284) => do_eventfd(init_val: u32),
-            (Fallocate = 285) => handle_unsupported(),
+            (Fallocate = 285) => do_fallocate(fd: FileDesc, mode: u32, offset: off_t, len: off_t),
             (TimerfdSettime = 286) => handle_unsupported(),
             (TimerfdGettime = 287) => handle_unsupported(),
             (Accept4 = 288) => do_accept4(fd: c_int, addr: *mut libc::sockaddr, addr_len: *mut libc::socklen_t, flags: c_int),

test/file/main.c

@@ -2,6 +2,7 @@
 #include <sys/uio.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <stdlib.h>
 #include "test_fs.h"
 
 // ============================================================================
@@ -162,6 +163,46 @@ static int __test_lseek(const char *file_path) {
     return 0;
 }
 
+static int __test_posix_fallocate(const char *file_path) {
+    int fd = open(file_path, O_RDWR);
+    if (fd < 0) {
+        THROW_ERROR("failed to open a file to read/write");
+    }
+    off_t offset = -1;
+    off_t len = 100;
+    if (posix_fallocate(fd, offset, len) != EINVAL) {
+        THROW_ERROR("failed to call posix_fallocate with invalid offset");
+    }
+    offset = 16;
+    len = 0;
+    if (posix_fallocate(fd, offset, len) != EINVAL) {
+        THROW_ERROR("failed to call posix_fallocate with invalid len");
+    }
+    len = 48;
+    if (posix_fallocate(fd, offset, len) != 0) {
+        THROW_ERROR("failed to call posix_fallocate");
+    }
+    struct stat stat_buf;
+    if (fstat(fd, &stat_buf) < 0) {
+        THROW_ERROR("failed to stat file");
+    }
+    if (stat_buf.st_size < offset + len) {
+        THROW_ERROR("failed to check the len after posix_fallocate");
+    }
+
+    char *read_buf = malloc(stat_buf.st_size);
+    if (read_buf == NULL) {
+        THROW_ERROR("failed to malloc buf to read");
+    }
+    if (read(fd, read_buf, stat_buf.st_size) != stat_buf.st_size) {
+        THROW_ERROR("failed to read correct size of fallocated file");
+    }
+
+    free(read_buf);
+    close(fd);
+    return 0;
+}
+
 typedef int(*test_file_func_t)(const char *);
 
 static int test_file_framework(test_file_func_t fn) {
@@ -195,6 +236,10 @@ static int test_lseek() {
     return test_file_framework(__test_lseek);
 }
 
+static int test_posix_fallocate() {
+    return test_file_framework(__test_posix_fallocate);
+}
+
 // ============================================================================
 // Test suite main
 // ============================================================================
@@ -204,6 +249,7 @@ static test_case_t test_cases[] = {
     TEST_CASE(test_pwrite_pread),
     TEST_CASE(test_writev_readv),
     TEST_CASE(test_lseek),
+    TEST_CASE(test_posix_fallocate),
 };
 
 int main(int argc, const char *argv[]) {