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- // SPDX-License-Identifier: MIT
- /*
- * VirtualBox Guest Shared Folders support: Directory inode and file operations
- *
- * Copyright (C) 2006-2018 Oracle Corporation
- */
- #include <linux/namei.h>
- #include <linux/vbox_utils.h>
- #include "vfsmod.h"
- static int vboxsf_dir_open(struct inode *inode, struct file *file)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
- struct shfl_createparms params = {};
- struct vboxsf_dir_info *sf_d;
- int err;
- sf_d = vboxsf_dir_info_alloc();
- if (!sf_d)
- return -ENOMEM;
- params.handle = SHFL_HANDLE_NIL;
- params.create_flags = SHFL_CF_DIRECTORY | SHFL_CF_ACT_OPEN_IF_EXISTS |
- SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;
- err = vboxsf_create_at_dentry(file_dentry(file), ¶ms);
- if (err)
- goto err_free_dir_info;
- if (params.result != SHFL_FILE_EXISTS) {
- err = -ENOENT;
- goto err_close;
- }
- err = vboxsf_dir_read_all(sbi, sf_d, params.handle);
- if (err)
- goto err_close;
- vboxsf_close(sbi->root, params.handle);
- file->private_data = sf_d;
- return 0;
- err_close:
- vboxsf_close(sbi->root, params.handle);
- err_free_dir_info:
- vboxsf_dir_info_free(sf_d);
- return err;
- }
- static int vboxsf_dir_release(struct inode *inode, struct file *file)
- {
- if (file->private_data)
- vboxsf_dir_info_free(file->private_data);
- return 0;
- }
- static unsigned int vboxsf_get_d_type(u32 mode)
- {
- unsigned int d_type;
- switch (mode & SHFL_TYPE_MASK) {
- case SHFL_TYPE_FIFO:
- d_type = DT_FIFO;
- break;
- case SHFL_TYPE_DEV_CHAR:
- d_type = DT_CHR;
- break;
- case SHFL_TYPE_DIRECTORY:
- d_type = DT_DIR;
- break;
- case SHFL_TYPE_DEV_BLOCK:
- d_type = DT_BLK;
- break;
- case SHFL_TYPE_FILE:
- d_type = DT_REG;
- break;
- case SHFL_TYPE_SYMLINK:
- d_type = DT_LNK;
- break;
- case SHFL_TYPE_SOCKET:
- d_type = DT_SOCK;
- break;
- case SHFL_TYPE_WHITEOUT:
- d_type = DT_WHT;
- break;
- default:
- d_type = DT_UNKNOWN;
- break;
- }
- return d_type;
- }
- static bool vboxsf_dir_emit(struct file *dir, struct dir_context *ctx)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(file_inode(dir)->i_sb);
- struct vboxsf_dir_info *sf_d = dir->private_data;
- struct shfl_dirinfo *info;
- struct vboxsf_dir_buf *b;
- unsigned int d_type;
- loff_t i, cur = 0;
- ino_t fake_ino;
- void *end;
- int err;
- list_for_each_entry(b, &sf_d->info_list, head) {
- try_next_entry:
- if (ctx->pos >= cur + b->entries) {
- cur += b->entries;
- continue;
- }
- /*
- * Note the vboxsf_dir_info objects we are iterating over here
- * are variable sized, so the info pointer may end up being
- * unaligned. This is how we get the data from the host.
- * Since vboxsf is only supported on x86 machines this is not
- * a problem.
- */
- for (i = 0, info = b->buf; i < ctx->pos - cur; i++) {
- end = &info->name.string.utf8[info->name.size];
- /* Only happens if the host gives us corrupt data */
- if (WARN_ON(end > (b->buf + b->used)))
- return false;
- info = end;
- }
- end = &info->name.string.utf8[info->name.size];
- if (WARN_ON(end > (b->buf + b->used)))
- return false;
- /* Info now points to the right entry, emit it. */
- d_type = vboxsf_get_d_type(info->info.attr.mode);
- /*
- * On 32-bit systems pos is 64-bit signed, while ino is 32-bit
- * unsigned so fake_ino may overflow, check for this.
- */
- if ((ino_t)(ctx->pos + 1) != (u64)(ctx->pos + 1)) {
- vbg_err("vboxsf: fake ino overflow, truncating dir\n");
- return false;
- }
- fake_ino = ctx->pos + 1;
- if (sbi->nls) {
- char d_name[NAME_MAX];
- err = vboxsf_nlscpy(sbi, d_name, NAME_MAX,
- info->name.string.utf8,
- info->name.length);
- if (err) {
- /* skip erroneous entry and proceed */
- ctx->pos += 1;
- goto try_next_entry;
- }
- return dir_emit(ctx, d_name, strlen(d_name),
- fake_ino, d_type);
- }
- return dir_emit(ctx, info->name.string.utf8, info->name.length,
- fake_ino, d_type);
- }
- return false;
- }
- static int vboxsf_dir_iterate(struct file *dir, struct dir_context *ctx)
- {
- bool emitted;
- do {
- emitted = vboxsf_dir_emit(dir, ctx);
- if (emitted)
- ctx->pos += 1;
- } while (emitted);
- return 0;
- }
- const struct file_operations vboxsf_dir_fops = {
- .open = vboxsf_dir_open,
- .iterate = vboxsf_dir_iterate,
- .release = vboxsf_dir_release,
- .read = generic_read_dir,
- .llseek = generic_file_llseek,
- };
- /*
- * This is called during name resolution/lookup to check if the @dentry in
- * the cache is still valid. the job is handled by vboxsf_inode_revalidate.
- */
- static int vboxsf_dentry_revalidate(struct dentry *dentry, unsigned int flags)
- {
- if (flags & LOOKUP_RCU)
- return -ECHILD;
- if (d_really_is_positive(dentry))
- return vboxsf_inode_revalidate(dentry) == 0;
- else
- return vboxsf_stat_dentry(dentry, NULL) == -ENOENT;
- }
- const struct dentry_operations vboxsf_dentry_ops = {
- .d_revalidate = vboxsf_dentry_revalidate
- };
- /* iops */
- static struct dentry *vboxsf_dir_lookup(struct inode *parent,
- struct dentry *dentry,
- unsigned int flags)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- struct shfl_fsobjinfo fsinfo;
- struct inode *inode;
- int err;
- dentry->d_time = jiffies;
- err = vboxsf_stat_dentry(dentry, &fsinfo);
- if (err) {
- inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
- } else {
- inode = vboxsf_new_inode(parent->i_sb);
- if (!IS_ERR(inode))
- vboxsf_init_inode(sbi, inode, &fsinfo);
- }
- return d_splice_alias(inode, dentry);
- }
- static int vboxsf_dir_instantiate(struct inode *parent, struct dentry *dentry,
- struct shfl_fsobjinfo *info)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- struct vboxsf_inode *sf_i;
- struct inode *inode;
- inode = vboxsf_new_inode(parent->i_sb);
- if (IS_ERR(inode))
- return PTR_ERR(inode);
- sf_i = VBOXSF_I(inode);
- /* The host may have given us different attr then requested */
- sf_i->force_restat = 1;
- vboxsf_init_inode(sbi, inode, info);
- d_instantiate(dentry, inode);
- return 0;
- }
- static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
- umode_t mode, bool is_dir, bool excl, u64 *handle_ret)
- {
- struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- struct shfl_createparms params = {};
- int err;
- params.handle = SHFL_HANDLE_NIL;
- params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW | SHFL_CF_ACCESS_READWRITE;
- if (is_dir)
- params.create_flags |= SHFL_CF_DIRECTORY;
- if (excl)
- params.create_flags |= SHFL_CF_ACT_FAIL_IF_EXISTS;
- params.info.attr.mode = (mode & 0777) |
- (is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE);
- params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING;
- err = vboxsf_create_at_dentry(dentry, ¶ms);
- if (err)
- return err;
- if (params.result != SHFL_FILE_CREATED)
- return -EPERM;
- err = vboxsf_dir_instantiate(parent, dentry, ¶ms.info);
- if (err)
- goto out;
- /* parent directory access/change time changed */
- sf_parent_i->force_restat = 1;
- out:
- if (err == 0 && handle_ret)
- *handle_ret = params.handle;
- else
- vboxsf_close(sbi->root, params.handle);
- return err;
- }
- static int vboxsf_dir_mkfile(struct inode *parent, struct dentry *dentry,
- umode_t mode, bool excl)
- {
- return vboxsf_dir_create(parent, dentry, mode, false, excl, NULL);
- }
- static int vboxsf_dir_mkdir(struct inode *parent, struct dentry *dentry,
- umode_t mode)
- {
- return vboxsf_dir_create(parent, dentry, mode, true, true, NULL);
- }
- static int vboxsf_dir_atomic_open(struct inode *parent, struct dentry *dentry,
- struct file *file, unsigned int flags, umode_t mode)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- struct vboxsf_handle *sf_handle;
- struct dentry *res = NULL;
- u64 handle;
- int err;
- if (d_in_lookup(dentry)) {
- res = vboxsf_dir_lookup(parent, dentry, 0);
- if (IS_ERR(res))
- return PTR_ERR(res);
- if (res)
- dentry = res;
- }
- /* Only creates */
- if (!(flags & O_CREAT) || d_really_is_positive(dentry))
- return finish_no_open(file, res);
- err = vboxsf_dir_create(parent, dentry, mode, false, flags & O_EXCL, &handle);
- if (err)
- goto out;
- sf_handle = vboxsf_create_sf_handle(d_inode(dentry), handle, SHFL_CF_ACCESS_READWRITE);
- if (IS_ERR(sf_handle)) {
- vboxsf_close(sbi->root, handle);
- err = PTR_ERR(sf_handle);
- goto out;
- }
- err = finish_open(file, dentry, generic_file_open);
- if (err) {
- /* This also closes the handle passed to vboxsf_create_sf_handle() */
- vboxsf_release_sf_handle(d_inode(dentry), sf_handle);
- goto out;
- }
- file->private_data = sf_handle;
- file->f_mode |= FMODE_CREATED;
- out:
- dput(res);
- return err;
- }
- static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
- struct inode *inode = d_inode(dentry);
- struct shfl_string *path;
- u32 flags;
- int err;
- if (S_ISDIR(inode->i_mode))
- flags = SHFL_REMOVE_DIR;
- else
- flags = SHFL_REMOVE_FILE;
- if (S_ISLNK(inode->i_mode))
- flags |= SHFL_REMOVE_SYMLINK;
- path = vboxsf_path_from_dentry(sbi, dentry);
- if (IS_ERR(path))
- return PTR_ERR(path);
- err = vboxsf_remove(sbi->root, path, flags);
- __putname(path);
- if (err)
- return err;
- /* parent directory access/change time changed */
- sf_parent_i->force_restat = 1;
- return 0;
- }
- static int vboxsf_dir_rename(struct inode *old_parent,
- struct dentry *old_dentry,
- struct inode *new_parent,
- struct dentry *new_dentry,
- unsigned int flags)
- {
- struct vboxsf_sbi *sbi = VBOXSF_SBI(old_parent->i_sb);
- struct vboxsf_inode *sf_old_parent_i = VBOXSF_I(old_parent);
- struct vboxsf_inode *sf_new_parent_i = VBOXSF_I(new_parent);
- u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS;
- struct shfl_string *old_path, *new_path;
- int err;
- if (flags)
- return -EINVAL;
- old_path = vboxsf_path_from_dentry(sbi, old_dentry);
- if (IS_ERR(old_path))
- return PTR_ERR(old_path);
- new_path = vboxsf_path_from_dentry(sbi, new_dentry);
- if (IS_ERR(new_path)) {
- err = PTR_ERR(new_path);
- goto err_put_old_path;
- }
- if (d_inode(old_dentry)->i_mode & S_IFDIR)
- shfl_flags = 0;
- err = vboxsf_rename(sbi->root, old_path, new_path, shfl_flags);
- if (err == 0) {
- /* parent directories access/change time changed */
- sf_new_parent_i->force_restat = 1;
- sf_old_parent_i->force_restat = 1;
- }
- __putname(new_path);
- err_put_old_path:
- __putname(old_path);
- return err;
- }
- static int vboxsf_dir_symlink(struct inode *parent, struct dentry *dentry,
- const char *symname)
- {
- struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
- struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
- int symname_size = strlen(symname) + 1;
- struct shfl_string *path, *ssymname;
- struct shfl_fsobjinfo info;
- int err;
- path = vboxsf_path_from_dentry(sbi, dentry);
- if (IS_ERR(path))
- return PTR_ERR(path);
- ssymname = kmalloc(SHFLSTRING_HEADER_SIZE + symname_size, GFP_KERNEL);
- if (!ssymname) {
- __putname(path);
- return -ENOMEM;
- }
- ssymname->length = symname_size - 1;
- ssymname->size = symname_size;
- memcpy(ssymname->string.utf8, symname, symname_size);
- err = vboxsf_symlink(sbi->root, path, ssymname, &info);
- kfree(ssymname);
- __putname(path);
- if (err) {
- /* -EROFS means symlinks are note support -> -EPERM */
- return (err == -EROFS) ? -EPERM : err;
- }
- err = vboxsf_dir_instantiate(parent, dentry, &info);
- if (err)
- return err;
- /* parent directory access/change time changed */
- sf_parent_i->force_restat = 1;
- return 0;
- }
- const struct inode_operations vboxsf_dir_iops = {
- .lookup = vboxsf_dir_lookup,
- .create = vboxsf_dir_mkfile,
- .mkdir = vboxsf_dir_mkdir,
- .atomic_open = vboxsf_dir_atomic_open,
- .rmdir = vboxsf_dir_unlink,
- .unlink = vboxsf_dir_unlink,
- .rename = vboxsf_dir_rename,
- .symlink = vboxsf_dir_symlink,
- .getattr = vboxsf_getattr,
- .setattr = vboxsf_setattr,
- };
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