1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  fs/partitions/aix.c
4 *
5 *  Copyright (C) 2012-2013 Philippe De Muyter <phdm@macqel.be>
6 */
7
8#include "check.h"
9
10struct lvm_rec {
11	char lvm_id[4]; /* "_LVM" */
12	char reserved4[16];
13	__be32 lvmarea_len;
14	__be32 vgda_len;
15	__be32 vgda_psn[2];
16	char reserved36[10];
17	__be16 pp_size; /* log2(pp_size) */
18	char reserved46[12];
19	__be16 version;
20	};
21
22struct vgda {
23	__be32 secs;
24	__be32 usec;
25	char reserved8[16];
26	__be16 numlvs;
27	__be16 maxlvs;
28	__be16 pp_size;
29	__be16 numpvs;
30	__be16 total_vgdas;
31	__be16 vgda_size;
32	};
33
34struct lvd {
35	__be16 lv_ix;
36	__be16 res2;
37	__be16 res4;
38	__be16 maxsize;
39	__be16 lv_state;
40	__be16 mirror;
41	__be16 mirror_policy;
42	__be16 num_lps;
43	__be16 res10[8];
44	};
45
46struct lvname {
47	char name[64];
48	};
49
50struct ppe {
51	__be16 lv_ix;
52	unsigned short res2;
53	unsigned short res4;
54	__be16 lp_ix;
55	unsigned short res8[12];
56	};
57
58struct pvd {
59	char reserved0[16];
60	__be16 pp_count;
61	char reserved18[2];
62	__be32 psn_part1;
63	char reserved24[8];
64	struct ppe ppe[1016];
65	};
66
67#define LVM_MAXLVS 256
68
69/**
70 * read_lba(): Read bytes from disk, starting at given LBA
71 * @state
72 * @lba
73 * @buffer
74 * @count
75 *
76 * Description:  Reads @count bytes from @state->disk into @buffer.
77 * Returns number of bytes read on success, 0 on error.
78 */
79static size_t read_lba(struct parsed_partitions *state, u64 lba, u8 *buffer,
80			size_t count)
81{
82	size_t totalreadcount = 0;
83
84	if (!buffer || lba + count / 512 > get_capacity(state->disk) - 1ULL)
85		return 0;
86
87	while (count) {
88		int copied = 512;
89		Sector sect;
90		unsigned char *data = read_part_sector(state, lba++, &sect);
91		if (!data)
92			break;
93		if (copied > count)
94			copied = count;
95		memcpy(buffer, data, copied);
96		put_dev_sector(sect);
97		buffer += copied;
98		totalreadcount += copied;
99		count -= copied;
100	}
101	return totalreadcount;
102}
103
104/**
105 * alloc_pvd(): reads physical volume descriptor
106 * @state
107 * @lba
108 *
109 * Description: Returns pvd on success,  NULL on error.
110 * Allocates space for pvd and fill it with disk blocks at @lba
111 * Notes: remember to free pvd when you're done!
112 */
113static struct pvd *alloc_pvd(struct parsed_partitions *state, u32 lba)
114{
115	size_t count = sizeof(struct pvd);
116	struct pvd *p;
117
118	p = kmalloc(count, GFP_KERNEL);
119	if (!p)
120		return NULL;
121
122	if (read_lba(state, lba, (u8 *) p, count) < count) {
123		kfree(p);
124		return NULL;
125	}
126	return p;
127}
128
129/**
130 * alloc_lvn(): reads logical volume names
131 * @state
132 * @lba
133 *
134 * Description: Returns lvn on success,  NULL on error.
135 * Allocates space for lvn and fill it with disk blocks at @lba
136 * Notes: remember to free lvn when you're done!
137 */
138static struct lvname *alloc_lvn(struct parsed_partitions *state, u32 lba)
139{
140	size_t count = sizeof(struct lvname) * LVM_MAXLVS;
141	struct lvname *p;
142
143	p = kmalloc(count, GFP_KERNEL);
144	if (!p)
145		return NULL;
146
147	if (read_lba(state, lba, (u8 *) p, count) < count) {
148		kfree(p);
149		return NULL;
150	}
151	return p;
152}
153
154int aix_partition(struct parsed_partitions *state)
155{
156	int ret = 0;
157	Sector sect;
158	unsigned char *d;
159	u32 pp_bytes_size;
160	u32 pp_blocks_size = 0;
161	u32 vgda_sector = 0;
162	u32 vgda_len = 0;
163	int numlvs = 0;
164	struct pvd *pvd = NULL;
165	struct lv_info {
166		unsigned short pps_per_lv;
167		unsigned short pps_found;
168		unsigned char lv_is_contiguous;
169	} *lvip;
170	struct lvname *n = NULL;
171
172	d = read_part_sector(state, 7, &sect);
173	if (d) {
174		struct lvm_rec *p = (struct lvm_rec *)d;
175		u16 lvm_version = be16_to_cpu(p->version);
176		char tmp[64];
177
178		if (lvm_version == 1) {
179			int pp_size_log2 = be16_to_cpu(p->pp_size);
180
181			pp_bytes_size = 1 << pp_size_log2;
182			pp_blocks_size = pp_bytes_size / 512;
183			snprintf(tmp, sizeof(tmp),
184				" AIX LVM header version %u found\n",
185				lvm_version);
186			vgda_len = be32_to_cpu(p->vgda_len);
187			vgda_sector = be32_to_cpu(p->vgda_psn[0]);
188		} else {
189			snprintf(tmp, sizeof(tmp),
190				" unsupported AIX LVM version %d found\n",
191				lvm_version);
192		}
193		strlcat(state->pp_buf, tmp, PAGE_SIZE);
194		put_dev_sector(sect);
195	}
196	if (vgda_sector && (d = read_part_sector(state, vgda_sector, &sect))) {
197		struct vgda *p = (struct vgda *)d;
198
199		numlvs = be16_to_cpu(p->numlvs);
200		put_dev_sector(sect);
201	}
202	lvip = kcalloc(state->limit, sizeof(struct lv_info), GFP_KERNEL);
203	if (!lvip)
204		return 0;
205	if (numlvs && (d = read_part_sector(state, vgda_sector + 1, &sect))) {
206		struct lvd *p = (struct lvd *)d;
207		int i;
208
209		n = alloc_lvn(state, vgda_sector + vgda_len - 33);
210		if (n) {
211			int foundlvs = 0;
212
213			for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
214				lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
215				if (lvip[i].pps_per_lv)
216					foundlvs += 1;
217			}
218			/* pvd loops depend on n[].name and lvip[].pps_per_lv */
219			pvd = alloc_pvd(state, vgda_sector + 17);
220		}
221		put_dev_sector(sect);
222	}
223	if (pvd) {
224		int numpps = be16_to_cpu(pvd->pp_count);
225		int psn_part1 = be32_to_cpu(pvd->psn_part1);
226		int i;
227		int cur_lv_ix = -1;
228		int next_lp_ix = 1;
229		int lp_ix;
230
231		for (i = 0; i < numpps; i += 1) {
232			struct ppe *p = pvd->ppe + i;
233			unsigned int lv_ix;
234
235			lp_ix = be16_to_cpu(p->lp_ix);
236			if (!lp_ix) {
237				next_lp_ix = 1;
238				continue;
239			}
240			lv_ix = be16_to_cpu(p->lv_ix) - 1;
241			if (lv_ix >= state->limit) {
242				cur_lv_ix = -1;
243				continue;
244			}
245			lvip[lv_ix].pps_found += 1;
246			if (lp_ix == 1) {
247				cur_lv_ix = lv_ix;
248				next_lp_ix = 1;
249			} else if (lv_ix != cur_lv_ix || lp_ix != next_lp_ix) {
250				next_lp_ix = 1;
251				continue;
252			}
253			if (lp_ix == lvip[lv_ix].pps_per_lv) {
254				char tmp[70];
255
256				put_partition(state, lv_ix + 1,
257				  (i + 1 - lp_ix) * pp_blocks_size + psn_part1,
258				  lvip[lv_ix].pps_per_lv * pp_blocks_size);
259				snprintf(tmp, sizeof(tmp), " <%s>\n",
260					 n[lv_ix].name);
261				strlcat(state->pp_buf, tmp, PAGE_SIZE);
262				lvip[lv_ix].lv_is_contiguous = 1;
263				ret = 1;
264				next_lp_ix = 1;
265			} else
266				next_lp_ix += 1;
267		}
268		for (i = 0; i < state->limit; i += 1)
269			if (lvip[i].pps_found && !lvip[i].lv_is_contiguous) {
270				char tmp[sizeof(n[i].name) + 1]; // null char
271
272				snprintf(tmp, sizeof(tmp), "%s", n[i].name);
273				pr_warn("partition %s (%u pp's found) is "
274					"not contiguous\n",
275					tmp, lvip[i].pps_found);
276			}
277		kfree(pvd);
278	}
279	kfree(n);
280	kfree(lvip);
281	return ret;
282}
283