1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * file.c |
4 | * |
5 | * PURPOSE |
6 | * File handling routines for the OSTA-UDF(tm) filesystem. |
7 | * |
8 | * COPYRIGHT |
9 | * (C) 1998-1999 Dave Boynton |
10 | * (C) 1998-2004 Ben Fennema |
11 | * (C) 1999-2000 Stelias Computing Inc |
12 | * |
13 | * HISTORY |
14 | * |
15 | * 10/02/98 dgb Attempt to integrate into udf.o |
16 | * 10/07/98 Switched to using generic_readpage, etc., like isofs |
17 | * And it works! |
18 | * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but |
19 | * ICBTAG_FLAG_AD_IN_ICB. |
20 | * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c |
21 | * 05/12/99 Preliminary file write support |
22 | */ |
23 | |
24 | #include "udfdecl.h" |
25 | #include <linux/fs.h> |
26 | #include <linux/uaccess.h> |
27 | #include <linux/kernel.h> |
28 | #include <linux/string.h> /* memset */ |
29 | #include <linux/capability.h> |
30 | #include <linux/errno.h> |
31 | #include <linux/pagemap.h> |
32 | #include <linux/uio.h> |
33 | |
34 | #include "udf_i.h" |
35 | #include "udf_sb.h" |
36 | |
37 | static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf) |
38 | { |
39 | struct vm_area_struct *vma = vmf->vma; |
40 | struct inode *inode = file_inode(f: vma->vm_file); |
41 | struct address_space *mapping = inode->i_mapping; |
42 | struct page *page = vmf->page; |
43 | loff_t size; |
44 | unsigned int end; |
45 | vm_fault_t ret = VM_FAULT_LOCKED; |
46 | int err; |
47 | |
48 | sb_start_pagefault(sb: inode->i_sb); |
49 | file_update_time(file: vma->vm_file); |
50 | filemap_invalidate_lock_shared(mapping); |
51 | lock_page(page); |
52 | size = i_size_read(inode); |
53 | if (page->mapping != inode->i_mapping || page_offset(page) >= size) { |
54 | unlock_page(page); |
55 | ret = VM_FAULT_NOPAGE; |
56 | goto out_unlock; |
57 | } |
58 | /* Space is already allocated for in-ICB file */ |
59 | if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) |
60 | goto out_dirty; |
61 | if (page->index == size >> PAGE_SHIFT) |
62 | end = size & ~PAGE_MASK; |
63 | else |
64 | end = PAGE_SIZE; |
65 | err = __block_write_begin(page, pos: 0, len: end, get_block: udf_get_block); |
66 | if (err) { |
67 | unlock_page(page); |
68 | ret = vmf_fs_error(err); |
69 | goto out_unlock; |
70 | } |
71 | |
72 | block_commit_write(page, from: 0, to: end); |
73 | out_dirty: |
74 | set_page_dirty(page); |
75 | wait_for_stable_page(page); |
76 | out_unlock: |
77 | filemap_invalidate_unlock_shared(mapping); |
78 | sb_end_pagefault(sb: inode->i_sb); |
79 | return ret; |
80 | } |
81 | |
82 | static const struct vm_operations_struct udf_file_vm_ops = { |
83 | .fault = filemap_fault, |
84 | .map_pages = filemap_map_pages, |
85 | .page_mkwrite = udf_page_mkwrite, |
86 | }; |
87 | |
88 | static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
89 | { |
90 | ssize_t retval; |
91 | struct file *file = iocb->ki_filp; |
92 | struct inode *inode = file_inode(f: file); |
93 | struct udf_inode_info *iinfo = UDF_I(inode); |
94 | |
95 | inode_lock(inode); |
96 | |
97 | retval = generic_write_checks(iocb, from); |
98 | if (retval <= 0) |
99 | goto out; |
100 | |
101 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && |
102 | inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + |
103 | iocb->ki_pos + iov_iter_count(i: from))) { |
104 | filemap_invalidate_lock(mapping: inode->i_mapping); |
105 | retval = udf_expand_file_adinicb(inode); |
106 | filemap_invalidate_unlock(mapping: inode->i_mapping); |
107 | if (retval) |
108 | goto out; |
109 | } |
110 | |
111 | retval = __generic_file_write_iter(iocb, from); |
112 | out: |
113 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) { |
114 | down_write(sem: &iinfo->i_data_sem); |
115 | iinfo->i_lenAlloc = inode->i_size; |
116 | up_write(sem: &iinfo->i_data_sem); |
117 | } |
118 | inode_unlock(inode); |
119 | |
120 | if (retval > 0) { |
121 | mark_inode_dirty(inode); |
122 | retval = generic_write_sync(iocb, count: retval); |
123 | } |
124 | |
125 | return retval; |
126 | } |
127 | |
128 | long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
129 | { |
130 | struct inode *inode = file_inode(f: filp); |
131 | long old_block, new_block; |
132 | int result; |
133 | |
134 | if (file_permission(file: filp, MAY_READ) != 0) { |
135 | udf_debug("no permission to access inode %lu\n" , inode->i_ino); |
136 | return -EPERM; |
137 | } |
138 | |
139 | if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || |
140 | (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { |
141 | udf_debug("invalid argument to udf_ioctl\n" ); |
142 | return -EINVAL; |
143 | } |
144 | |
145 | switch (cmd) { |
146 | case UDF_GETVOLIDENT: |
147 | if (copy_to_user(to: (char __user *)arg, |
148 | from: UDF_SB(sb: inode->i_sb)->s_volume_ident, n: 32)) |
149 | return -EFAULT; |
150 | return 0; |
151 | case UDF_RELOCATE_BLOCKS: |
152 | if (!capable(CAP_SYS_ADMIN)) |
153 | return -EPERM; |
154 | if (get_user(old_block, (long __user *)arg)) |
155 | return -EFAULT; |
156 | result = udf_relocate_blocks(inode->i_sb, |
157 | old_block, &new_block); |
158 | if (result == 0) |
159 | result = put_user(new_block, (long __user *)arg); |
160 | return result; |
161 | case UDF_GETEASIZE: |
162 | return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); |
163 | case UDF_GETEABLOCK: |
164 | return copy_to_user(to: (char __user *)arg, |
165 | from: UDF_I(inode)->i_data, |
166 | n: UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; |
167 | default: |
168 | return -ENOIOCTLCMD; |
169 | } |
170 | |
171 | return 0; |
172 | } |
173 | |
174 | static int udf_release_file(struct inode *inode, struct file *filp) |
175 | { |
176 | if (filp->f_mode & FMODE_WRITE && |
177 | atomic_read(v: &inode->i_writecount) == 1) { |
178 | /* |
179 | * Grab i_mutex to avoid races with writes changing i_size |
180 | * while we are running. |
181 | */ |
182 | inode_lock(inode); |
183 | down_write(sem: &UDF_I(inode)->i_data_sem); |
184 | udf_discard_prealloc(inode); |
185 | udf_truncate_tail_extent(inode); |
186 | up_write(sem: &UDF_I(inode)->i_data_sem); |
187 | inode_unlock(inode); |
188 | } |
189 | return 0; |
190 | } |
191 | |
192 | static int udf_file_mmap(struct file *file, struct vm_area_struct *vma) |
193 | { |
194 | file_accessed(file); |
195 | vma->vm_ops = &udf_file_vm_ops; |
196 | |
197 | return 0; |
198 | } |
199 | |
200 | const struct file_operations udf_file_operations = { |
201 | .read_iter = generic_file_read_iter, |
202 | .unlocked_ioctl = udf_ioctl, |
203 | .open = generic_file_open, |
204 | .mmap = udf_file_mmap, |
205 | .write_iter = udf_file_write_iter, |
206 | .release = udf_release_file, |
207 | .fsync = generic_file_fsync, |
208 | .splice_read = filemap_splice_read, |
209 | .splice_write = iter_file_splice_write, |
210 | .llseek = generic_file_llseek, |
211 | }; |
212 | |
213 | static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, |
214 | struct iattr *attr) |
215 | { |
216 | struct inode *inode = d_inode(dentry); |
217 | struct super_block *sb = inode->i_sb; |
218 | int error; |
219 | |
220 | error = setattr_prepare(&nop_mnt_idmap, dentry, attr); |
221 | if (error) |
222 | return error; |
223 | |
224 | if ((attr->ia_valid & ATTR_UID) && |
225 | UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && |
226 | !uid_eq(left: attr->ia_uid, right: UDF_SB(sb)->s_uid)) |
227 | return -EPERM; |
228 | if ((attr->ia_valid & ATTR_GID) && |
229 | UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && |
230 | !gid_eq(left: attr->ia_gid, right: UDF_SB(sb)->s_gid)) |
231 | return -EPERM; |
232 | |
233 | if ((attr->ia_valid & ATTR_SIZE) && |
234 | attr->ia_size != i_size_read(inode)) { |
235 | error = udf_setsize(inode, attr->ia_size); |
236 | if (error) |
237 | return error; |
238 | } |
239 | |
240 | if (attr->ia_valid & ATTR_MODE) |
241 | udf_update_extra_perms(inode, mode: attr->ia_mode); |
242 | |
243 | setattr_copy(&nop_mnt_idmap, inode, attr); |
244 | mark_inode_dirty(inode); |
245 | return 0; |
246 | } |
247 | |
248 | const struct inode_operations udf_file_inode_operations = { |
249 | .setattr = udf_setattr, |
250 | }; |
251 | |