These functions are used in the imported code, which is not enabled
yet. This required to expand functionality of vfscore_install_fd and
friends with locking and reference counting.
Signed-off-by: Yuri Volchkov <yuri.volchkov@xxxxxxxxx>
---
lib/vfscore/fd.c | 71 ++++++++++++++++++++++++++++--
lib/vfscore/file.c | 22 ++++++++-
lib/vfscore/include/vfscore/file.h | 9 +++-
3 files changed, 96 insertions(+), 6 deletions(-)
diff --git a/lib/vfscore/fd.c b/lib/vfscore/fd.c
index 6c220428..5abed969 100644
--- a/lib/vfscore/fd.c
+++ b/lib/vfscore/fd.c
@@ -74,20 +74,45 @@ exit:
void vfscore_put_fd(int fd)
{
+ struct vfscore_file *fp;
+ unsigned long flags;
+
UK_ASSERT(fd < (int) FDTABLE_MAX_FILES);
/* Currently it is not allowed to free std(in|out|err) */
UK_ASSERT(fd > 2);
- __uk_clear_bit(fd, &fdtable.bitmap);
+ flags = ukplat_lcpu_save_irqf();
+ __uk_clear_bit(fd, &fdtable.bitmap);\
+ fp = fdtable.files[fd];
+ fdtable.files[fd] = NULL;
+ ukplat_lcpu_restore_irqf(flags);
+
+ fdrop(fp);
}
-void vfscore_install_fd(int fd, struct vfscore_file *file)
+int vfscore_install_fd(int fd, struct vfscore_file *file)
{
- UK_ASSERT(fd < (int) FDTABLE_MAX_FILES);
- UK_ASSERT(file);
+ unsigned long flags;
+ struct vfscore_file *orig;
+
+ if ((fd >= (int) FDTABLE_MAX_FILES) || (!file))
+ return -EBADF;
+
+ fhold(file);
file->fd = fd;
+
+ flags = ukplat_lcpu_save_irqf();
+ orig = fdtable.files[fd];
fdtable.files[fd] = file;
+ ukplat_lcpu_restore_irqf(flags);
+
+ fdrop(file);
+
+ if (orig)
+ fdrop(orig);
+
+ return 0;
}
struct vfscore_file *vfscore_get_file(int fd)
@@ -101,12 +126,50 @@ struct vfscore_file *vfscore_get_file(int fd)
if (!(fdtable.bitmap & ((uint64_t) 1 << fd)))
goto exit;
ret = fdtable.files[fd];
+ fhold(ret);
exit:
ukplat_lcpu_restore_irqf(flags);
return ret;
}
+int fget(int fd, struct vfscore_file **out_fp)
+{
+ int ret = 0;
+ struct vfscore_file *fp = vfscore_get_file(fd);
+
+ if (!fp)
+ ret = EBADF;
+ else
+ *out_fp = fp;
+
+ return ret;
+}
+
+int fdalloc(struct vfscore_file *fp, int *newfd)
+{
+ int fd, ret = 0;
+
+ fhold(fp);
+
+ fd = vfscore_alloc_fd();
+ if (fd < 0) {
+ ret = fd;
+ goto exit;
+ }
+
+ ret = vfscore_install_fd(fd, fp);
+ if (ret)
+ fdrop(fp);
+ else
+ *newfd = fd;
+
+exit:
+ return ret;
+}
+
+
+/* TODO: move this constructor to main.c */
__constructor static void fdtable_init(void)
{
memset(&fdtable, 0, sizeof(fdtable));
diff --git a/lib/vfscore/file.c b/lib/vfscore/file.c
index e7adf1a3..0f6dfa93 100644
--- a/lib/vfscore/file.c
+++ b/lib/vfscore/file.c
@@ -38,7 +38,7 @@
#include <uk/print.h>
#include <vfscore/file.h>
#include <uk/assert.h>
-
+#include <uk/arch/atomic.h>
int close(int fd)
{
@@ -95,3 +95,23 @@ ssize_t read(int fd, void *buf, size_t count)
return file->fops->read(file, buf, count);
}
+
+/* TODO: remove stub */
+#define vfs_close(fp) (0)
+
+int fdrop(struct vfscore_file *fp)
+{
+ int ret = 0;
+ int prev = ukarch_dec(&fp->f_count);
+
+ if (prev == 0)
+ UK_CRASH("Unbalanced fhold/fdrop");
+
+ if (prev == 1)
+ ret = vfs_close(fp);
+ return ret;
+}
+void fhold(struct vfscore_file *fp)
+{
+ ukarch_inc(&fp->f_count);
+}
diff --git a/lib/vfscore/include/vfscore/file.h
b/lib/vfscore/include/vfscore/file.h
index 3d8d667f..84eb35d7 100644
--- a/lib/vfscore/include/vfscore/file.h
+++ b/lib/vfscore/include/vfscore/file.h
@@ -53,14 +53,21 @@ struct vfscore_fops {
struct vfscore_file {
int fd;
+ int f_count; /* reference count */
const struct vfscore_fops *fops;
};
int vfscore_alloc_fd(void);
void vfscore_put_fd(int fd);
-void vfscore_install_fd(int fd, struct vfscore_file *file);
+int vfscore_install_fd(int fd, struct vfscore_file *file);
struct vfscore_file *vfscore_get_file(int fd);
+/*
+ * File descriptors reference count
+ */
