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Diffstat (limited to 'drivers/staging/vboxsf/file.c')
-rw-r--r--drivers/staging/vboxsf/file.c370
1 files changed, 0 insertions, 370 deletions
diff --git a/drivers/staging/vboxsf/file.c b/drivers/staging/vboxsf/file.c
deleted file mode 100644
index 4b61ccf83fca..000000000000
--- a/drivers/staging/vboxsf/file.c
+++ /dev/null
@@ -1,370 +0,0 @@
-// SPDX-License-Identifier: MIT
-/*
- * VirtualBox Guest Shared Folders support: Regular file inode and file ops.
- *
- * Copyright (C) 2006-2018 Oracle Corporation
- */
-
-#include <linux/mm.h>
-#include <linux/page-flags.h>
-#include <linux/pagemap.h>
-#include <linux/highmem.h>
-#include <linux/sizes.h>
-#include "vfsmod.h"
-
-struct vboxsf_handle {
- u64 handle;
- u32 root;
- u32 access_flags;
- struct kref refcount;
- struct list_head head;
-};
-
-static int vboxsf_file_open(struct inode *inode, struct file *file)
-{
- struct vboxsf_inode *sf_i = VBOXSF_I(inode);
- struct shfl_createparms params = {};
- struct vboxsf_handle *sf_handle;
- u32 access_flags = 0;
- int err;
-
- sf_handle = kmalloc(sizeof(*sf_handle), GFP_KERNEL);
- if (!sf_handle)
- return -ENOMEM;
-
- /*
- * We check the value of params.handle afterwards to find out if
- * the call succeeded or failed, as the API does not seem to cleanly
- * distinguish error and informational messages.
- *
- * Furthermore, we must set params.handle to SHFL_HANDLE_NIL to
- * make the shared folders host service use our mode parameter.
- */
- params.handle = SHFL_HANDLE_NIL;
- if (file->f_flags & O_CREAT) {
- params.create_flags |= SHFL_CF_ACT_CREATE_IF_NEW;
- /*
- * We ignore O_EXCL, as the Linux kernel seems to call create
- * beforehand itself, so O_EXCL should always fail.
- */
- if (file->f_flags & O_TRUNC)
- params.create_flags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
- else
- params.create_flags |= SHFL_CF_ACT_OPEN_IF_EXISTS;
- } else {
- params.create_flags |= SHFL_CF_ACT_FAIL_IF_NEW;
- if (file->f_flags & O_TRUNC)
- params.create_flags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
- }
-
- switch (file->f_flags & O_ACCMODE) {
- case O_RDONLY:
- access_flags |= SHFL_CF_ACCESS_READ;
- break;
-
- case O_WRONLY:
- access_flags |= SHFL_CF_ACCESS_WRITE;
- break;
-
- case O_RDWR:
- access_flags |= SHFL_CF_ACCESS_READWRITE;
- break;
-
- default:
- WARN_ON(1);
- }
-
- if (file->f_flags & O_APPEND)
- access_flags |= SHFL_CF_ACCESS_APPEND;
-
- params.create_flags |= access_flags;
- params.info.attr.mode = inode->i_mode;
-
- err = vboxsf_create_at_dentry(file_dentry(file), &params);
- if (err == 0 && params.handle == SHFL_HANDLE_NIL)
- err = (params.result == SHFL_FILE_EXISTS) ? -EEXIST : -ENOENT;
- if (err) {
- kfree(sf_handle);
- return err;
- }
-
- /* the host may have given us different attr then requested */
- sf_i->force_restat = 1;
-
- /* init our handle struct and add it to the inode's handles list */
- sf_handle->handle = params.handle;
- sf_handle->root = VBOXSF_SBI(inode->i_sb)->root;
- sf_handle->access_flags = access_flags;
- kref_init(&sf_handle->refcount);
-
- mutex_lock(&sf_i->handle_list_mutex);
- list_add(&sf_handle->head, &sf_i->handle_list);
- mutex_unlock(&sf_i->handle_list_mutex);
-
- file->private_data = sf_handle;
- return 0;
-}
-
-static void vboxsf_handle_release(struct kref *refcount)
-{
- struct vboxsf_handle *sf_handle =
- container_of(refcount, struct vboxsf_handle, refcount);
-
- vboxsf_close(sf_handle->root, sf_handle->handle);
- kfree(sf_handle);
-}
-
-static int vboxsf_file_release(struct inode *inode, struct file *file)
-{
- struct vboxsf_inode *sf_i = VBOXSF_I(inode);
- struct vboxsf_handle *sf_handle = file->private_data;
-
- /*
- * When a file is closed on our (the guest) side, we want any subsequent
- * accesses done on the host side to see all changes done from our side.
- */
- filemap_write_and_wait(inode->i_mapping);
-
- mutex_lock(&sf_i->handle_list_mutex);
- list_del(&sf_handle->head);
- mutex_unlock(&sf_i->handle_list_mutex);
-
- kref_put(&sf_handle->refcount, vboxsf_handle_release);
- return 0;
-}
-
-/*
- * Write back dirty pages now, because there may not be any suitable
- * open files later
- */
-static void vboxsf_vma_close(struct vm_area_struct *vma)
-{
- filemap_write_and_wait(vma->vm_file->f_mapping);
-}
-
-static const struct vm_operations_struct vboxsf_file_vm_ops = {
- .close = vboxsf_vma_close,
- .fault = filemap_fault,
- .map_pages = filemap_map_pages,
-};
-
-static int vboxsf_file_mmap(struct file *file, struct vm_area_struct *vma)
-{
- int err;
-
- err = generic_file_mmap(file, vma);
- if (!err)
- vma->vm_ops = &vboxsf_file_vm_ops;
-
- return err;
-}
-
-/*
- * Note that since we are accessing files on the host's filesystem, files
- * may always be changed underneath us by the host!
- *
- * The vboxsf API between the guest and the host does not offer any functions
- * to deal with this. There is no inode-generation to check for changes, no
- * events / callback on changes and no way to lock files.
- *
- * To avoid returning stale data when a file gets *opened* on our (the guest)
- * side, we do a "stat" on the host side, then compare the mtime with the
- * last known mtime and invalidate the page-cache if they differ.
- * This is done from vboxsf_inode_revalidate().
- *
- * When reads are done through the read_iter fop, it is possible to do
- * further cache revalidation then, there are 3 options to deal with this:
- *
- * 1) Rely solely on the revalidation done at open time
- * 2) Do another "stat" and compare mtime again. Unfortunately the vboxsf
- * host API does not allow stat on handles, so we would need to use
- * file->f_path.dentry and the stat will then fail if the file was unlinked
- * or renamed (and there is no thing like NFS' silly-rename). So we get:
- * 2a) "stat" and compare mtime, on stat failure invalidate the cache
- * 2b) "stat" and compare mtime, on stat failure do nothing
- * 3) Simply always call invalidate_inode_pages2_range on the range of the read
- *
- * Currently we are keeping things KISS and using option 1. this allows
- * directly using generic_file_read_iter without wrapping it.
- *
- * This means that only data written on the host side before open() on
- * the guest side is guaranteed to be seen by the guest. If necessary
- * we may provide other read-cache strategies in the future and make this
- * configurable through a mount option.
- */
-const struct file_operations vboxsf_reg_fops = {
- .llseek = generic_file_llseek,
- .read_iter = generic_file_read_iter,
- .write_iter = generic_file_write_iter,
- .mmap = vboxsf_file_mmap,
- .open = vboxsf_file_open,
- .release = vboxsf_file_release,
- .fsync = noop_fsync,
- .splice_read = generic_file_splice_read,
-};
-
-const struct inode_operations vboxsf_reg_iops = {
- .getattr = vboxsf_getattr,
- .setattr = vboxsf_setattr
-};
-
-static int vboxsf_readpage(struct file *file, struct page *page)
-{
- struct vboxsf_handle *sf_handle = file->private_data;
- loff_t off = page_offset(page);
- u32 nread = PAGE_SIZE;
- u8 *buf;
- int err;
-
- buf = kmap(page);
-
- err = vboxsf_read(sf_handle->root, sf_handle->handle, off, &nread, buf);
- if (err == 0) {
- memset(&buf[nread], 0, PAGE_SIZE - nread);
- flush_dcache_page(page);
- SetPageUptodate(page);
- } else {
- SetPageError(page);
- }
-
- kunmap(page);
- unlock_page(page);
- return err;
-}
-
-static struct vboxsf_handle *vboxsf_get_write_handle(struct vboxsf_inode *sf_i)
-{
- struct vboxsf_handle *h, *sf_handle = NULL;
-
- mutex_lock(&sf_i->handle_list_mutex);
- list_for_each_entry(h, &sf_i->handle_list, head) {
- if (h->access_flags == SHFL_CF_ACCESS_WRITE ||
- h->access_flags == SHFL_CF_ACCESS_READWRITE) {
- kref_get(&h->refcount);
- sf_handle = h;
- break;
- }
- }
- mutex_unlock(&sf_i->handle_list_mutex);
-
- return sf_handle;
-}
-
-static int vboxsf_writepage(struct page *page, struct writeback_control *wbc)
-{
- struct inode *inode = page->mapping->host;
- struct vboxsf_inode *sf_i = VBOXSF_I(inode);
- struct vboxsf_handle *sf_handle;
- loff_t off = page_offset(page);
- loff_t size = i_size_read(inode);
- u32 nwrite = PAGE_SIZE;
- u8 *buf;
- int err;
-
- if (off + PAGE_SIZE > size)
- nwrite = size & ~PAGE_MASK;
-
- sf_handle = vboxsf_get_write_handle(sf_i);
- if (!sf_handle)
- return -EBADF;
-
- buf = kmap(page);
- err = vboxsf_write(sf_handle->root, sf_handle->handle,
- off, &nwrite, buf);
- kunmap(page);
-
- kref_put(&sf_handle->refcount, vboxsf_handle_release);
-
- if (err == 0) {
- ClearPageError(page);
- /* mtime changed */
- sf_i->force_restat = 1;
- } else {
- ClearPageUptodate(page);
- }
-
- unlock_page(page);
- return err;
-}
-
-static int vboxsf_write_end(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned int len, unsigned int copied,
- struct page *page, void *fsdata)
-{
- struct inode *inode = mapping->host;
- struct vboxsf_handle *sf_handle = file->private_data;
- unsigned int from = pos & ~PAGE_MASK;
- u32 nwritten = len;
- u8 *buf;
- int err;
-
- buf = kmap(page);
- err = vboxsf_write(sf_handle->root, sf_handle->handle,
- pos, &nwritten, buf + from);
- kunmap(page);
-
- if (err) {
- nwritten = 0;
- goto out;
- }
-
- /* mtime changed */
- VBOXSF_I(inode)->force_restat = 1;
-
- if (!PageUptodate(page) && nwritten == PAGE_SIZE)
- SetPageUptodate(page);
-
- pos += nwritten;
- if (pos > inode->i_size)
- i_size_write(inode, pos);
-
-out:
- unlock_page(page);
- put_page(page);
-
- return nwritten;
-}
-
-const struct address_space_operations vboxsf_reg_aops = {
- .readpage = vboxsf_readpage,
- .writepage = vboxsf_writepage,
- .set_page_dirty = __set_page_dirty_nobuffers,
- .write_begin = simple_write_begin,
- .write_end = vboxsf_write_end,
-};
-
-static const char *vboxsf_get_link(struct dentry *dentry, struct inode *inode,
- struct delayed_call *done)
-{
- struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
- struct shfl_string *path;
- char *link;
- int err;
-
- if (!dentry)
- return ERR_PTR(-ECHILD);
-
- path = vboxsf_path_from_dentry(sbi, dentry);
- if (IS_ERR(path))
- return (char *)path;
-
- link = kzalloc(PATH_MAX, GFP_KERNEL);
- if (!link) {
- __putname(path);
- return ERR_PTR(-ENOMEM);
- }
-
- err = vboxsf_readlink(sbi->root, path, PATH_MAX, link);
- __putname(path);
- if (err) {
- kfree(link);
- return ERR_PTR(err);
- }
-
- set_delayed_call(done, kfree_link, link);
- return link;
-}
-
-const struct inode_operations vboxsf_lnk_iops = {
- .get_link = vboxsf_get_link
-};