[Minios-devel] [UNIKRAFT PATCH v2] lib/vfscore: Enable fcntl() function

[Costin Lupu <costin.lupu@xxxxxxxxx>]

This patch enables and adapt the existing fcntl() implementation which was
previously imported from OSv. Beside that, it also handles F_DUPFD_CLOEXEC
case, which is heavily used by Python 3 interpreter.

Signed-off-by: Costin Lupu <costin.lupu@xxxxxxxxx>
---
 lib/vfscore/exportsyms.uk          |  1 +
 lib/vfscore/include/vfscore/file.h |  4 +++
 lib/vfscore/main.c                 | 41 +++++++++++++++++++-----------
 lib/vfscore/syscalls.c             |  2 ++
 4 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/lib/vfscore/exportsyms.uk b/lib/vfscore/exportsyms.uk
index 822e6ecc..e3d6723a 100644
--- a/lib/vfscore/exportsyms.uk
+++ b/lib/vfscore/exportsyms.uk
@@ -78,3 +78,4 @@ uk_syscall_writev
 dentry_alloc
 drele
 vrele
+fcntl
diff --git a/lib/vfscore/include/vfscore/file.h 
b/lib/vfscore/include/vfscore/file.h
index 51f0791a..354a414e 100644
--- a/lib/vfscore/include/vfscore/file.h
+++ b/lib/vfscore/include/vfscore/file.h
@@ -59,8 +59,12 @@ struct vfscore_file {
        void            *f_data;        /* file descriptor specific data */
        int             f_vfs_flags;    /* internal implementation flags */
        struct dentry   *f_dentry;
+       struct uk_mutex f_lock;
 };
 
+#define FD_LOCK(fp)       uk_mutex_lock(&(fp->f_lock))
+#define FD_UNLOCK(fp)     uk_mutex_unlock(&(fp->f_lock))
+
 int vfscore_alloc_fd(void);
 void vfscore_put_fd(int fd);
 int vfscore_install_fd(int fd, struct vfscore_file *file);
diff --git a/lib/vfscore/main.c b/lib/vfscore/main.c
index be055b78..8d0e4b2c 100644
--- a/lib/vfscore/main.c
+++ b/lib/vfscore/main.c
@@ -1425,17 +1425,22 @@ int dup2(int oldfd, int newfd)
  */
 #define SETFL (O_APPEND | O_ASYNC | O_DIRECT | O_NOATIME | O_NONBLOCK)
 
-#if 0
 UK_TRACEPOINT(trace_vfs_fcntl, "%d %d 0x%x", int, int, int);
 UK_TRACEPOINT(trace_vfs_fcntl_ret, "\"%s\"", int);
 UK_TRACEPOINT(trace_vfs_fcntl_err, "%d", int);
 
-int fcntl(int fd, int cmd, int arg)
+int fcntl(int fd, int cmd, ...)
 {
+       int arg;
+       va_list ap;
        struct vfscore_file *fp;
        int ret = 0, error;
        int tmp;
 
+       va_start(ap, cmd);
+       arg = va_arg(ap, int);
+       va_end(ap);
+
        trace_vfs_fcntl(fd, cmd, arg);
        error = fget(fd, &fp);
        if (error)
@@ -1450,7 +1455,7 @@ int fcntl(int fd, int cmd, int arg)
        // ignored in OSv anyway, as it doesn't support exec().
        switch (cmd) {
        case F_DUPFD:
-               error = _fdalloc(fp, &ret, arg);
+               error = fdalloc(fp, &ret);
                if (error)
                        goto out_errno;
                break;
@@ -1467,35 +1472,42 @@ int fcntl(int fd, int cmd, int arg)
                // As explained above, the O_CLOEXEC should have been in 
f_flags,
                // and shouldn't be returned. Linux always returns 0100000 ("the
                // flag formerly known as O_LARGEFILE) so let's do it too.
-               ret = (oflags(fp->f_flags) & ~O_CLOEXEC) | 0100000;
+               ret = (vfscore_oflags(fp->f_flags) & ~O_CLOEXEC) | 0100000;
                break;
        case F_SETFL:
                FD_LOCK(fp);
-               fp->f_flags = fflags((oflags(fp->f_flags) & ~SETFL) |
+               fp->f_flags = vfscore_fflags((vfscore_oflags(fp->f_flags) & 
~SETFL) |
                                (arg & SETFL));
                FD_UNLOCK(fp);
 
+#if defined(FIONBIO) && defined(FIOASYNC)
                /* Sync nonblocking/async state with file flags */
                tmp = fp->f_flags & FNONBLOCK;
-               fp->ioctl(FIONBIO, &tmp);
+               vfs_ioctl(fp, FIONBIO, &tmp);
                tmp = fp->f_flags & FASYNC;
-               fp->ioctl(FIOASYNC, &tmp);
-
+               vfs_ioctl(fp, FIOASYNC, &tmp);
+#endif
+               break;
+       case F_DUPFD_CLOEXEC:
+               error = fdalloc(fp, &ret);
+               if (error)
+                       goto out_errno;
+               fp->f_flags |= O_CLOEXEC;
                break;
        case F_SETLK:
-               WARN_ONCE("fcntl(F_SETLK) stubbed\n");
+               uk_pr_warn("fcntl(F_SETLK) stubbed\n");
                break;
        case F_GETLK:
-               WARN_ONCE("fcntl(F_GETLK) stubbed\n");
+               uk_pr_warn("fcntl(F_GETLK) stubbed\n");
                break;
        case F_SETLKW:
-               WARN_ONCE("fcntl(F_SETLKW) stubbed\n");
+               uk_pr_warn("fcntl(F_SETLKW) stubbed\n");
                break;
        case F_SETOWN:
-               WARN_ONCE("fcntl(F_SETOWN) stubbed\n");
+               uk_pr_warn("fcntl(F_SETOWN) stubbed\n");
                break;
        default:
-               kprintf("unsupported fcntl cmd 0x%x\n", cmd);
+               uk_pr_err("unsupported fcntl cmd 0x%x\n", cmd);
                error = EINVAL;
        }
 
@@ -1505,12 +1517,11 @@ int fcntl(int fd, int cmd, int arg)
        trace_vfs_fcntl_ret(ret);
        return ret;
 
-       out_errno:
+out_errno:
        trace_vfs_fcntl_err(error);
        errno = error;
        return -1;
 }
-#endif
 
 UK_TRACEPOINT(trace_vfs_access, "\"%s\" 0%0o", const char*, int);
 UK_TRACEPOINT(trace_vfs_access_ret, "");
diff --git a/lib/vfscore/syscalls.c b/lib/vfscore/syscalls.c
index f9666c4c..54adc2d2 100644
--- a/lib/vfscore/syscalls.c
+++ b/lib/vfscore/syscalls.c
@@ -210,6 +210,8 @@ sys_open(char *path, int flags, mode_t mode, struct 
vfscore_file **fpp)
        fp->f_dentry = dp;
        dp = NULL;
 
+       uk_mutex_init(&fp->f_lock);
+
        error = VOP_OPEN(vp, fp);
        if (error) {
                vn_unlock(vp);
-- 
2.20.1


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