2 * QEMU Enhanced Disk Format Table I/O
4 * Copyright IBM, Corp. 2010
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
8 * Anthony Liguori <aliguori@us.ibm.com>
10 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
11 * See the COPYING.LIB file in the top-level directory.
15 #include "qemu/osdep.h"
17 #include "qemu/sockets.h" /* for EINPROGRESS on Windows */
19 #include "qemu/bswap.h"
20 #include "qemu/memalign.h"
22 /* Called with table_lock held. */
23 static int coroutine_fn qed_read_table(BDRVQEDState *s, uint64_t offset,
26 unsigned int bytes = s->header.cluster_size * s->header.table_size;
31 trace_qed_read_table(s, offset, table);
33 qemu_co_mutex_unlock(&s->table_lock);
34 ret = bdrv_co_pread(s->bs->file, offset, bytes, table->offsets, 0);
35 qemu_co_mutex_lock(&s->table_lock);
40 /* Byteswap offsets */
41 noffsets = bytes / sizeof(uint64_t);
42 for (i = 0; i < noffsets; i++) {
43 table->offsets[i] = le64_to_cpu(table->offsets[i]);
49 trace_qed_read_table_cb(s, table, ret);
54 * Write out an updated part or all of a table
57 * @offset: Offset of table in image file, in bytes
59 * @index: Index of first element
60 * @n: Number of elements
61 * @flush: Whether or not to sync to disk
63 * Called with table_lock held.
65 static int coroutine_fn qed_write_table(BDRVQEDState *s, uint64_t offset,
66 QEDTable *table, unsigned int index,
67 unsigned int n, bool flush)
69 unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
70 unsigned int start, end, i;
75 trace_qed_write_table(s, offset, table, index, n);
77 /* Calculate indices of the first and one after last elements */
78 start = index & ~sector_mask;
79 end = (index + n + sector_mask) & ~sector_mask;
81 len_bytes = (end - start) * sizeof(uint64_t);
83 new_table = qemu_blockalign(s->bs, len_bytes);
86 for (i = start; i < end; i++) {
87 uint64_t le_offset = cpu_to_le64(table->offsets[i]);
88 new_table->offsets[i - start] = le_offset;
91 /* Adjust for offset into table */
92 offset += start * sizeof(uint64_t);
94 qemu_co_mutex_unlock(&s->table_lock);
95 ret = bdrv_co_pwrite(s->bs->file, offset, len_bytes, new_table->offsets, 0);
96 qemu_co_mutex_lock(&s->table_lock);
97 trace_qed_write_table_cb(s, table, flush, ret);
103 ret = bdrv_flush(s->bs);
111 qemu_vfree(new_table);
115 int coroutine_fn qed_read_l1_table_sync(BDRVQEDState *s)
117 return qed_read_table(s, s->header.l1_table_offset, s->l1_table);
120 /* Called with table_lock held. */
121 int coroutine_fn qed_write_l1_table(BDRVQEDState *s, unsigned int index,
124 BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
125 return qed_write_table(s, s->header.l1_table_offset,
126 s->l1_table, index, n, false);
129 int coroutine_fn qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
132 return qed_write_l1_table(s, index, n);
135 /* Called with table_lock held. */
136 int coroutine_fn qed_read_l2_table(BDRVQEDState *s, QEDRequest *request,
141 qed_unref_l2_cache_entry(request->l2_table);
143 /* Check for cached L2 entry */
144 request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
145 if (request->l2_table) {
149 request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
150 request->l2_table->table = qed_alloc_table(s);
152 BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
153 ret = qed_read_table(s, offset, request->l2_table->table);
156 /* can't trust loaded L2 table anymore */
157 qed_unref_l2_cache_entry(request->l2_table);
158 request->l2_table = NULL;
160 request->l2_table->offset = offset;
162 qed_commit_l2_cache_entry(&s->l2_cache, request->l2_table);
164 /* This is guaranteed to succeed because we just committed the entry
167 request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
168 assert(request->l2_table != NULL);
174 int coroutine_fn qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
177 return qed_read_l2_table(s, request, offset);
180 /* Called with table_lock held. */
181 int coroutine_fn qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
182 unsigned int index, unsigned int n,
185 BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE);
186 return qed_write_table(s, request->l2_table->offset,
187 request->l2_table->table, index, n, flush);
190 int coroutine_fn qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
191 unsigned int index, unsigned int n,
194 return qed_write_l2_table(s, request, index, n, flush);