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#include "fs/file.h"
#include "fs/vfs.h"
#include "fs/vnode.h"
#include "kernel.h"
#include "mm/slab.h"
#include "util/debug.h"
#include "util/string.h"
static slab_allocator_t *file_allocator;
void file_init(void)
{
file_allocator = slab_allocator_create("file", sizeof(file_t));
}
void fref(file_t *f)
{
KASSERT(f->f_mode <= FMODE_MAX_VALUE && f->f_vnode);
f->f_refcount++;
if (f->f_vnode)
{
dbg(DBG_FREF, "fref: 0x%p, 0x%p ino %u, up to %lu\n", f,
f->f_vnode->vn_fs, f->f_vnode->vn_vno, f->f_refcount);
}
else
{
dbg(DBG_FREF, "fref: 0x%p up to %lu\n", f, f->f_refcount);
}
}
/*
* Create a file, initialize its members, vref the vnode, call acquire() on the
* vnode if the function pointer is non-NULL, and set the file descriptor in
* curproc->p_files.
*
* On successful return, the vnode's refcount should be incremented by one,
* the file's refcount should be 1, and curproc->p_files[fd] should point to
* the file being returned.
*/
file_t *fcreate(int fd, vnode_t *vnode, unsigned int mode)
{
KASSERT(!curproc->p_files[fd]);
file_t *file = slab_obj_alloc(file_allocator);
if (!file)
return NULL;
memset(file, 0, sizeof(file_t));
file->f_mode = mode;
vref(file->f_vnode = vnode);
if (vnode->vn_ops->acquire)
vnode->vn_ops->acquire(vnode, file);
curproc->p_files[fd] = file;
fref(file);
return file;
}
/*
* Perform bounds checking on the fd, use curproc->p_files to get the file,
* fref it if it exists, and return.
*/
file_t *fget(int fd)
{
if (fd < 0 || fd >= NFILES)
return NULL;
file_t *file = curproc->p_files[fd];
if (file)
fref(file);
return file;
}
/*
* Decrement the refcount, and set *filep to NULL.
*
* If the refcount drops to 0, call release on the vnode if the function pointer
* is non-null, vput() file's vnode, and free the file memory.
*
* Regardless of the ending refcount, *filep == NULL on return.
*/
void fput(file_t **filep)
{
file_t *file = *filep;
*filep = NULL;
KASSERT(file && file->f_mode <= FMODE_MAX_VALUE);
KASSERT(file->f_refcount > 0);
if (file->f_refcount != 1)
KASSERT(file->f_vnode);
file->f_refcount--;
if (file->f_vnode)
{
dbg(DBG_FREF, "fput: 0x%p, 0x%p ino %u, down to %lu\n", file,
file->f_vnode->vn_fs, file->f_vnode->vn_vno, file->f_refcount);
}
else
{
dbg(DBG_FREF, "fput: 0x%p down to %lu\n", file, file->f_refcount);
}
if (!file->f_refcount)
{
if (file->f_vnode)
{
vlock(file->f_vnode);
if (file->f_vnode->vn_ops->release)
file->f_vnode->vn_ops->release(file->f_vnode, file);
vput_locked(&file->f_vnode);
}
slab_obj_free(file_allocator, file);
}
}
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