diff options
Diffstat (limited to 'drivers/staging/vboxsf/dir.c')
| -rw-r--r-- | drivers/staging/vboxsf/dir.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/staging/vboxsf/dir.c b/drivers/staging/vboxsf/dir.c new file mode 100644 index 000000000000..f260b5cc1646 --- /dev/null +++ b/drivers/staging/vboxsf/dir.c @@ -0,0 +1,418 @@ +// 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; + size_t size; + 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++) { + size = offsetof(struct shfl_dirinfo, name.string) + + info->name.size; + info = (struct shfl_dirinfo *)((uintptr_t)info + size); + } + + /* 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 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 keep_iterating; + + for (keep_iterating = true; keep_iterating; ctx->pos += 1) + keep_iterating = vboxsf_dir_emit(dir, ctx); + + 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, int is_dir) +{ + 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_ACT_FAIL_IF_EXISTS | + SHFL_CF_ACCESS_READWRITE | + (is_dir ? SHFL_CF_DIRECTORY : 0); + 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; + + vboxsf_close(sbi->root, params.handle); + + err = vboxsf_dir_instantiate(parent, dentry, ¶ms.info); + if (err) + return err; + + /* parent directory access/change time changed */ + sf_parent_i->force_restat = 1; + + return 0; +} + +static int vboxsf_dir_mkfile(struct inode *parent, struct dentry *dentry, + umode_t mode, bool excl) +{ + return vboxsf_dir_create(parent, dentry, mode, 0); +} + +static int vboxsf_dir_mkdir(struct inode *parent, struct dentry *dentry, + umode_t mode) +{ + return vboxsf_dir_create(parent, dentry, mode, 1); +} + +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, + .rmdir = vboxsf_dir_unlink, + .unlink = vboxsf_dir_unlink, + .rename = vboxsf_dir_rename, + .symlink = vboxsf_dir_symlink, + .getattr = vboxsf_getattr, + .setattr = vboxsf_setattr, +}; |