diff options
Diffstat (limited to 'fs/udf/file.c')
| -rw-r--r-- | fs/udf/file.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/fs/udf/file.c b/fs/udf/file.c new file mode 100644 index 0000000000..0ceac4b593 --- /dev/null +++ b/fs/udf/file.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * file.c + * + * PURPOSE + * File handling routines for the OSTA-UDF(tm) filesystem. + * + * COPYRIGHT + * (C) 1998-1999 Dave Boynton + * (C) 1998-2004 Ben Fennema + * (C) 1999-2000 Stelias Computing Inc + * + * HISTORY + * + * 10/02/98 dgb Attempt to integrate into udf.o + * 10/07/98 Switched to using generic_readpage, etc., like isofs + * And it works! + * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but + * ICBTAG_FLAG_AD_IN_ICB. + * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c + * 05/12/99 Preliminary file write support + */ + +#include "udfdecl.h" +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/kernel.h> +#include <linux/string.h> /* memset */ +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/pagemap.h> +#include <linux/uio.h> + +#include "udf_i.h" +#include "udf_sb.h" + +static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct inode *inode = file_inode(vma->vm_file); + struct address_space *mapping = inode->i_mapping; + struct page *page = vmf->page; + loff_t size; + unsigned int end; + vm_fault_t ret = VM_FAULT_LOCKED; + int err; + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + filemap_invalidate_lock_shared(mapping); + lock_page(page); + size = i_size_read(inode); + if (page->mapping != inode->i_mapping || page_offset(page) >= size) { + unlock_page(page); + ret = VM_FAULT_NOPAGE; + goto out_unlock; + } + /* Space is already allocated for in-ICB file */ + if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) + goto out_dirty; + if (page->index == size >> PAGE_SHIFT) + end = size & ~PAGE_MASK; + else + end = PAGE_SIZE; + err = __block_write_begin(page, 0, end, udf_get_block); + if (err) { + unlock_page(page); + ret = vmf_fs_error(err); + goto out_unlock; + } + + block_commit_write(page, 0, end); +out_dirty: + set_page_dirty(page); + wait_for_stable_page(page); +out_unlock: + filemap_invalidate_unlock_shared(mapping); + sb_end_pagefault(inode->i_sb); + return ret; +} + +static const struct vm_operations_struct udf_file_vm_ops = { + .fault = filemap_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = udf_page_mkwrite, +}; + +static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + ssize_t retval; + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); + struct udf_inode_info *iinfo = UDF_I(inode); + + inode_lock(inode); + + retval = generic_write_checks(iocb, from); + if (retval <= 0) + goto out; + + if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && + inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + + iocb->ki_pos + iov_iter_count(from))) { + filemap_invalidate_lock(inode->i_mapping); + retval = udf_expand_file_adinicb(inode); + filemap_invalidate_unlock(inode->i_mapping); + if (retval) + goto out; + } + + retval = __generic_file_write_iter(iocb, from); +out: + if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) { + down_write(&iinfo->i_data_sem); + iinfo->i_lenAlloc = inode->i_size; + up_write(&iinfo->i_data_sem); + } + inode_unlock(inode); + + if (retval > 0) { + mark_inode_dirty(inode); + retval = generic_write_sync(iocb, retval); + } + + return retval; +} + +long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct inode *inode = file_inode(filp); + long old_block, new_block; + int result; + + if (file_permission(filp, MAY_READ) != 0) { + udf_debug("no permission to access inode %lu\n", inode->i_ino); + return -EPERM; + } + + if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || + (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { + udf_debug("invalid argument to udf_ioctl\n"); + return -EINVAL; + } + + switch (cmd) { + case UDF_GETVOLIDENT: + if (copy_to_user((char __user *)arg, + UDF_SB(inode->i_sb)->s_volume_ident, 32)) + return -EFAULT; + return 0; + case UDF_RELOCATE_BLOCKS: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + if (get_user(old_block, (long __user *)arg)) + return -EFAULT; + result = udf_relocate_blocks(inode->i_sb, + old_block, &new_block); + if (result == 0) + result = put_user(new_block, (long __user *)arg); + return result; + case UDF_GETEASIZE: + return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); + case UDF_GETEABLOCK: + return copy_to_user((char __user *)arg, + UDF_I(inode)->i_data, + UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; + default: + return -ENOIOCTLCMD; + } + + return 0; +} + +static int udf_release_file(struct inode *inode, struct file *filp) +{ + if (filp->f_mode & FMODE_WRITE && + atomic_read(&inode->i_writecount) == 1) { + /* + * Grab i_mutex to avoid races with writes changing i_size + * while we are running. + */ + inode_lock(inode); + down_write(&UDF_I(inode)->i_data_sem); + udf_discard_prealloc(inode); + udf_truncate_tail_extent(inode); + up_write(&UDF_I(inode)->i_data_sem); + inode_unlock(inode); + } + return 0; +} + +static int udf_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + file_accessed(file); + vma->vm_ops = &udf_file_vm_ops; + + return 0; +} + +const struct file_operations udf_file_operations = { + .read_iter = generic_file_read_iter, + .unlocked_ioctl = udf_ioctl, + .open = generic_file_open, + .mmap = udf_file_mmap, + .write_iter = udf_file_write_iter, + .release = udf_release_file, + .fsync = generic_file_fsync, + .splice_read = filemap_splice_read, + .splice_write = iter_file_splice_write, + .llseek = generic_file_llseek, +}; + +static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *attr) +{ + struct inode *inode = d_inode(dentry); + struct super_block *sb = inode->i_sb; + int error; + + error = setattr_prepare(&nop_mnt_idmap, dentry, attr); + if (error) + return error; + + if ((attr->ia_valid & ATTR_UID) && + UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && + !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) + return -EPERM; + if ((attr->ia_valid & ATTR_GID) && + UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && + !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) + return -EPERM; + + if ((attr->ia_valid & ATTR_SIZE) && + attr->ia_size != i_size_read(inode)) { + error = udf_setsize(inode, attr->ia_size); + if (error) + return error; + } + + if (attr->ia_valid & ATTR_MODE) + udf_update_extra_perms(inode, attr->ia_mode); + + setattr_copy(&nop_mnt_idmap, inode, attr); + mark_inode_dirty(inode); + return 0; +} + +const struct inode_operations udf_file_inode_operations = { + .setattr = udf_setattr, +}; |