xref: /linux/fs/ntfs/attrlist.c (revision cdd4dc3aebeab43a72ce0bc2b5bab6f0a80b97a5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Attribute list attribute handling code.
4  * Part of this file is based on code from the NTFS-3G.
5  *
6  * Copyright (c) 2004-2005 Anton Altaparmakov
7  * Copyright (c) 2004-2005 Yura Pakhuchiy
8  * Copyright (c)      2006 Szabolcs Szakacsits
9  * Copyright (c) 2025 LG Electronics Co., Ltd.
10  */
11 
12 #include "mft.h"
13 #include "attrib.h"
14 #include "attrlist.h"
15 
16 /*
17  * ntfs_attrlist_need - check whether inode need attribute list
18  * @ni:	opened ntfs inode for which perform check
19  *
20  * Check whether all are attributes belong to one MFT record, in that case
21  * attribute list is not needed.
22  *
23  * Return 1 if inode need attribute list, 0 if not, or -errno on error.
24  */
25 int ntfs_attrlist_need(struct ntfs_inode *ni)
26 {
27 	struct attr_list_entry *ale;
28 
29 	if (!ni) {
30 		ntfs_debug("Invalid arguments.\n");
31 		return -EINVAL;
32 	}
33 	ntfs_debug("Entering for inode 0x%llx.\n", (long long) ni->mft_no);
34 
35 	if (!NInoAttrList(ni)) {
36 		ntfs_debug("Inode haven't got attribute list.\n");
37 		return -EINVAL;
38 	}
39 
40 	if (!ni->attr_list) {
41 		ntfs_debug("Corrupt in-memory struct.\n");
42 		return -EINVAL;
43 	}
44 
45 	ale = (struct attr_list_entry *)ni->attr_list;
46 	while ((u8 *)ale < ni->attr_list + ni->attr_list_size) {
47 		if (MREF_LE(ale->mft_reference) != ni->mft_no)
48 			return 1;
49 		ale = (struct attr_list_entry *)((u8 *)ale + le16_to_cpu(ale->length));
50 	}
51 	return 0;
52 }
53 
54 int ntfs_attrlist_update(struct ntfs_inode *base_ni)
55 {
56 	struct inode *attr_vi;
57 	struct ntfs_inode *attr_ni;
58 	int err;
59 
60 	attr_vi = ntfs_attr_iget(VFS_I(base_ni), AT_ATTRIBUTE_LIST, AT_UNNAMED, 0);
61 	if (IS_ERR(attr_vi)) {
62 		err = PTR_ERR(attr_vi);
63 		return err;
64 	}
65 	attr_ni = NTFS_I(attr_vi);
66 
67 	err = ntfs_attr_truncate_i(attr_ni, base_ni->attr_list_size, HOLES_NO);
68 	if (err == -ENOSPC && attr_ni->mft_no == FILE_MFT) {
69 		err = ntfs_attr_truncate(attr_ni, 0);
70 		if (err || ntfs_attr_truncate_i(attr_ni, base_ni->attr_list_size, HOLES_NO) != 0) {
71 			iput(attr_vi);
72 			ntfs_error(base_ni->vol->sb,
73 					"Failed to truncate attribute list of inode %#llx",
74 					(long long)base_ni->mft_no);
75 			return -EIO;
76 		}
77 	} else if (err) {
78 		iput(attr_vi);
79 		ntfs_error(base_ni->vol->sb,
80 			   "Failed to truncate attribute list of inode %#llx",
81 			   (long long)base_ni->mft_no);
82 		return -EIO;
83 	}
84 
85 	i_size_write(attr_vi, base_ni->attr_list_size);
86 
87 	if (NInoNonResident(attr_ni) && !NInoAttrListNonResident(base_ni))
88 		NInoSetAttrListNonResident(base_ni);
89 
90 	if (ntfs_inode_attr_pwrite(attr_vi, 0, base_ni->attr_list_size,
91 				   base_ni->attr_list, false) !=
92 	    base_ni->attr_list_size) {
93 		iput(attr_vi);
94 		ntfs_error(base_ni->vol->sb,
95 			   "Failed to write attribute list of inode %#llx",
96 			   (long long)base_ni->mft_no);
97 		return -EIO;
98 	}
99 
100 	NInoSetAttrListDirty(base_ni);
101 	iput(attr_vi);
102 	return 0;
103 }
104 
105 /*
106  * ntfs_attrlist_entry_add - add an attribute list attribute entry
107  * @ni:	opened ntfs inode, which contains that attribute
108  * @attr: attribute record to add to attribute list
109  *
110  * Return 0 on success and -errno on error.
111  */
112 int ntfs_attrlist_entry_add(struct ntfs_inode *ni, struct attr_record *attr)
113 {
114 	struct attr_list_entry *ale;
115 	__le64 mref;
116 	struct ntfs_attr_search_ctx *ctx;
117 	u8 *new_al;
118 	int entry_len, entry_offset, err;
119 	struct mft_record *ni_mrec;
120 	u8 *old_al;
121 
122 	ntfs_debug("Entering for inode 0x%llx, attr 0x%x.\n",
123 			(long long) ni->mft_no,
124 			(unsigned int) le32_to_cpu(attr->type));
125 
126 	if (!ni || !attr) {
127 		ntfs_debug("Invalid arguments.\n");
128 		return -EINVAL;
129 	}
130 
131 	ni_mrec = map_mft_record(ni);
132 	if (IS_ERR(ni_mrec)) {
133 		ntfs_debug("Invalid arguments.\n");
134 		return -EIO;
135 	}
136 
137 	mref = MK_LE_MREF(ni->mft_no, le16_to_cpu(ni_mrec->sequence_number));
138 	unmap_mft_record(ni);
139 
140 	if (ni->nr_extents == -1)
141 		ni = ni->ext.base_ntfs_ino;
142 
143 	if (!NInoAttrList(ni)) {
144 		ntfs_debug("Attribute list isn't present.\n");
145 		return -ENOENT;
146 	}
147 
148 	/* Determine size and allocate memory for new attribute list. */
149 	entry_len = (sizeof(struct attr_list_entry) + sizeof(__le16) *
150 			attr->name_length + 7) & ~7;
151 	new_al = kvzalloc(ni->attr_list_size + entry_len, GFP_NOFS);
152 	if (!new_al)
153 		return -ENOMEM;
154 
155 	/* Find place for the new entry. */
156 	ctx = ntfs_attr_get_search_ctx(ni, NULL);
157 	if (!ctx) {
158 		err = -ENOMEM;
159 		ntfs_error(ni->vol->sb, "Failed to get search context");
160 		goto err_out;
161 	}
162 
163 	err = ntfs_attr_lookup(attr->type, (attr->name_length) ? (__le16 *)
164 			((u8 *)attr + le16_to_cpu(attr->name_offset)) :
165 			AT_UNNAMED, attr->name_length, CASE_SENSITIVE,
166 			(attr->non_resident) ? le64_to_cpu(attr->data.non_resident.lowest_vcn) :
167 			0, (attr->non_resident) ? NULL : ((u8 *)attr +
168 			le16_to_cpu(attr->data.resident.value_offset)), (attr->non_resident) ?
169 			0 : le32_to_cpu(attr->data.resident.value_length), ctx);
170 	if (!err) {
171 		/* Found some extent, check it to be before new extent. */
172 		if (ctx->al_entry->lowest_vcn == attr->data.non_resident.lowest_vcn) {
173 			err = -EEXIST;
174 			ntfs_debug("Such attribute already present in the attribute list.\n");
175 			ntfs_attr_put_search_ctx(ctx);
176 			goto err_out;
177 		}
178 		/* Add new entry after this extent. */
179 		ale = (struct attr_list_entry *)((u8 *)ctx->al_entry +
180 				le16_to_cpu(ctx->al_entry->length));
181 	} else {
182 		/* Check for real errors. */
183 		if (err != -ENOENT) {
184 			ntfs_debug("Attribute lookup failed.\n");
185 			ntfs_attr_put_search_ctx(ctx);
186 			goto err_out;
187 		}
188 		/* No previous extents found. */
189 		ale = ctx->al_entry;
190 	}
191 	/* Don't need it anymore, @ctx->al_entry points to @ni->attr_list. */
192 	ntfs_attr_put_search_ctx(ctx);
193 
194 	/* Determine new entry offset. */
195 	entry_offset = ((u8 *)ale - ni->attr_list);
196 	/* Set pointer to new entry. */
197 	ale = (struct attr_list_entry *)(new_al + entry_offset);
198 	memset(ale, 0, entry_len);
199 	/* Form new entry. */
200 	ale->type = attr->type;
201 	ale->length = cpu_to_le16(entry_len);
202 	ale->name_length = attr->name_length;
203 	ale->name_offset = offsetof(struct attr_list_entry, name);
204 	if (attr->non_resident)
205 		ale->lowest_vcn = attr->data.non_resident.lowest_vcn;
206 	else
207 		ale->lowest_vcn = 0;
208 	ale->mft_reference = mref;
209 	ale->instance = attr->instance;
210 	memcpy(ale->name, (u8 *)attr + le16_to_cpu(attr->name_offset),
211 			attr->name_length * sizeof(__le16));
212 
213 	/* Copy entries from old attribute list to new. */
214 	memcpy(new_al, ni->attr_list, entry_offset);
215 	memcpy(new_al + entry_offset + entry_len, ni->attr_list +
216 			entry_offset, ni->attr_list_size - entry_offset);
217 
218 	/* Set new runlist. */
219 	old_al = ni->attr_list;
220 	ni->attr_list = new_al;
221 	ni->attr_list_size = ni->attr_list_size + entry_len;
222 
223 	err = ntfs_attrlist_update(ni);
224 	if (err) {
225 		ni->attr_list = old_al;
226 		ni->attr_list_size -= entry_len;
227 		goto err_out;
228 	}
229 	kvfree(old_al);
230 	return 0;
231 err_out:
232 	kvfree(new_al);
233 	return err;
234 }
235 
236 /*
237  * ntfs_attrlist_entry_rm - remove an attribute list attribute entry
238  * @ctx:	attribute search context describing the attribute list entry
239  *
240  * Remove the attribute list entry @ctx->al_entry from the attribute list.
241  *
242  * Return 0 on success and -errno on error.
243  */
244 int ntfs_attrlist_entry_rm(struct ntfs_attr_search_ctx *ctx)
245 {
246 	u8 *new_al;
247 	int new_al_len;
248 	struct ntfs_inode *base_ni;
249 	struct attr_list_entry *ale;
250 
251 	if (!ctx || !ctx->ntfs_ino || !ctx->al_entry) {
252 		ntfs_debug("Invalid arguments.\n");
253 		return -EINVAL;
254 	}
255 
256 	if (ctx->base_ntfs_ino)
257 		base_ni = ctx->base_ntfs_ino;
258 	else
259 		base_ni = ctx->ntfs_ino;
260 	ale = ctx->al_entry;
261 
262 	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, lowest_vcn %lld.\n",
263 			(long long)ctx->ntfs_ino->mft_no,
264 			(unsigned int)le32_to_cpu(ctx->al_entry->type),
265 			(long long)le64_to_cpu(ctx->al_entry->lowest_vcn));
266 
267 	if (!NInoAttrList(base_ni)) {
268 		ntfs_debug("Attribute list isn't present.\n");
269 		return -ENOENT;
270 	}
271 
272 	/* Allocate memory for new attribute list. */
273 	new_al_len = base_ni->attr_list_size - le16_to_cpu(ale->length);
274 	new_al = kvzalloc(new_al_len, GFP_NOFS);
275 	if (!new_al)
276 		return -ENOMEM;
277 
278 	/* Copy entries from old attribute list to new. */
279 	memcpy(new_al, base_ni->attr_list, (u8 *)ale - base_ni->attr_list);
280 	memcpy(new_al + ((u8 *)ale - base_ni->attr_list), (u8 *)ale + le16_to_cpu(
281 				ale->length), new_al_len - ((u8 *)ale - base_ni->attr_list));
282 
283 	/* Set new runlist. */
284 	kvfree(base_ni->attr_list);
285 	base_ni->attr_list = new_al;
286 	base_ni->attr_list_size = new_al_len;
287 
288 	return ntfs_attrlist_update(base_ni);
289 }
290