Merge tag 'qemu-macppc-20230206' of https://github.com/mcayland/qemu into staging
[qemu/rayw.git] / block / qed-check.c
bloba6612be00f578012c773ca539c1e17af05ffe64a
1 /*
2 * QEMU Enhanced Disk Format Consistency Check
4 * Copyright IBM, Corp. 2010
6 * Authors:
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
10 * See the COPYING.LIB file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "block/block-io.h"
16 #include "qed.h"
18 typedef struct {
19 BDRVQEDState *s;
20 BdrvCheckResult *result;
21 bool fix; /* whether to fix invalid offsets */
23 uint64_t nclusters;
24 uint32_t *used_clusters; /* referenced cluster bitmap */
26 QEDRequest request;
27 } QEDCheck;
29 static bool qed_test_bit(uint32_t *bitmap, uint64_t n) {
30 return !!(bitmap[n / 32] & (1 << (n % 32)));
33 static void qed_set_bit(uint32_t *bitmap, uint64_t n) {
34 bitmap[n / 32] |= 1 << (n % 32);
37 /**
38 * Set bitmap bits for clusters
40 * @check: Check structure
41 * @offset: Starting offset in bytes
42 * @n: Number of clusters
44 static bool qed_set_used_clusters(QEDCheck *check, uint64_t offset,
45 unsigned int n)
47 uint64_t cluster = qed_bytes_to_clusters(check->s, offset);
48 unsigned int corruptions = 0;
50 while (n-- != 0) {
51 /* Clusters should only be referenced once */
52 if (qed_test_bit(check->used_clusters, cluster)) {
53 corruptions++;
56 qed_set_bit(check->used_clusters, cluster);
57 cluster++;
60 check->result->corruptions += corruptions;
61 return corruptions == 0;
64 /**
65 * Check an L2 table
67 * @ret: Number of invalid cluster offsets
69 static unsigned int qed_check_l2_table(QEDCheck *check, QEDTable *table)
71 BDRVQEDState *s = check->s;
72 unsigned int i, num_invalid = 0;
73 uint64_t last_offset = 0;
75 for (i = 0; i < s->table_nelems; i++) {
76 uint64_t offset = table->offsets[i];
78 if (qed_offset_is_unalloc_cluster(offset) ||
79 qed_offset_is_zero_cluster(offset)) {
80 continue;
82 check->result->bfi.allocated_clusters++;
83 if (last_offset && (last_offset + s->header.cluster_size != offset)) {
84 check->result->bfi.fragmented_clusters++;
86 last_offset = offset;
88 /* Detect invalid cluster offset */
89 if (!qed_check_cluster_offset(s, offset)) {
90 if (check->fix) {
91 table->offsets[i] = 0;
92 check->result->corruptions_fixed++;
93 } else {
94 check->result->corruptions++;
97 num_invalid++;
98 continue;
101 qed_set_used_clusters(check, offset, 1);
104 return num_invalid;
108 * Descend tables and check each cluster is referenced once only
110 static int coroutine_fn qed_check_l1_table(QEDCheck *check, QEDTable *table)
112 BDRVQEDState *s = check->s;
113 unsigned int i, num_invalid_l1 = 0;
114 int ret, last_error = 0;
116 /* Mark L1 table clusters used */
117 qed_set_used_clusters(check, s->header.l1_table_offset,
118 s->header.table_size);
120 for (i = 0; i < s->table_nelems; i++) {
121 unsigned int num_invalid_l2;
122 uint64_t offset = table->offsets[i];
124 if (qed_offset_is_unalloc_cluster(offset)) {
125 continue;
128 /* Detect invalid L2 offset */
129 if (!qed_check_table_offset(s, offset)) {
130 /* Clear invalid offset */
131 if (check->fix) {
132 table->offsets[i] = 0;
133 check->result->corruptions_fixed++;
134 } else {
135 check->result->corruptions++;
138 num_invalid_l1++;
139 continue;
142 if (!qed_set_used_clusters(check, offset, s->header.table_size)) {
143 continue; /* skip an invalid table */
146 ret = qed_read_l2_table_sync(s, &check->request, offset);
147 if (ret) {
148 check->result->check_errors++;
149 last_error = ret;
150 continue;
153 num_invalid_l2 = qed_check_l2_table(check,
154 check->request.l2_table->table);
156 /* Write out fixed L2 table */
157 if (num_invalid_l2 > 0 && check->fix) {
158 ret = qed_write_l2_table_sync(s, &check->request, 0,
159 s->table_nelems, false);
160 if (ret) {
161 check->result->check_errors++;
162 last_error = ret;
163 continue;
168 /* Drop reference to final table */
169 qed_unref_l2_cache_entry(check->request.l2_table);
170 check->request.l2_table = NULL;
172 /* Write out fixed L1 table */
173 if (num_invalid_l1 > 0 && check->fix) {
174 ret = qed_write_l1_table_sync(s, 0, s->table_nelems);
175 if (ret) {
176 check->result->check_errors++;
177 last_error = ret;
181 return last_error;
185 * Check for unreferenced (leaked) clusters
187 static void qed_check_for_leaks(QEDCheck *check)
189 BDRVQEDState *s = check->s;
190 uint64_t i;
192 for (i = s->header.header_size; i < check->nclusters; i++) {
193 if (!qed_test_bit(check->used_clusters, i)) {
194 check->result->leaks++;
200 * Mark an image clean once it passes check or has been repaired
202 static void qed_check_mark_clean(BDRVQEDState *s, BdrvCheckResult *result)
204 /* Skip if there were unfixable corruptions or I/O errors */
205 if (result->corruptions > 0 || result->check_errors > 0) {
206 return;
209 /* Skip if image is already marked clean */
210 if (!(s->header.features & QED_F_NEED_CHECK)) {
211 return;
214 /* Ensure fixes reach storage before clearing check bit */
215 bdrv_flush(s->bs);
217 s->header.features &= ~QED_F_NEED_CHECK;
218 qed_write_header_sync(s);
221 /* Called with table_lock held. */
222 int coroutine_fn qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix)
224 QEDCheck check = {
225 .s = s,
226 .result = result,
227 .nclusters = qed_bytes_to_clusters(s, s->file_size),
228 .request = { .l2_table = NULL },
229 .fix = fix,
231 int ret;
233 check.used_clusters = g_try_new0(uint32_t, (check.nclusters + 31) / 32);
234 if (check.nclusters && check.used_clusters == NULL) {
235 return -ENOMEM;
238 check.result->bfi.total_clusters =
239 DIV_ROUND_UP(s->header.image_size, s->header.cluster_size);
240 ret = qed_check_l1_table(&check, s->l1_table);
241 if (ret == 0) {
242 /* Only check for leaks if entire image was scanned successfully */
243 qed_check_for_leaks(&check);
245 if (fix) {
246 qed_check_mark_clean(s, result);
250 g_free(check.used_clusters);
251 return ret;