From 1f01e50b8330c24714ddca5841fdbb703076b121 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 29 Jun 2017 15:27:47 +0200 Subject: qed: protect table cache with CoMutex This makes the driver thread-safe. The CoMutex is dropped temporarily while accessing the data clusters or the backing file. Signed-off-by: Paolo Bonzini Message-Id: <20170629132749.997-10-pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi Reviewed-by: Fam Zheng Signed-off-by: Fam Zheng --- block/qed-table.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'block/qed-table.c') diff --git a/block/qed-table.c b/block/qed-table.c index ebee2c50f0..eead8b0fc7 100644 --- a/block/qed-table.c +++ b/block/qed-table.c @@ -18,6 +18,7 @@ #include "qed.h" #include "qemu/bswap.h" +/* Called either from qed_check or with table_lock held. */ static int qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table) { QEMUIOVector qiov; @@ -32,18 +33,22 @@ static int qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table) trace_qed_read_table(s, offset, table); + if (qemu_in_coroutine()) { + qemu_co_mutex_unlock(&s->table_lock); + } ret = bdrv_preadv(s->bs->file, offset, &qiov); + if (qemu_in_coroutine()) { + qemu_co_mutex_lock(&s->table_lock); + } if (ret < 0) { goto out; } /* Byteswap offsets */ - qed_acquire(s); noffsets = qiov.size / sizeof(uint64_t); for (i = 0; i < noffsets; i++) { table->offsets[i] = le64_to_cpu(table->offsets[i]); } - qed_release(s); ret = 0; out: @@ -61,6 +66,8 @@ out: * @index: Index of first element * @n: Number of elements * @flush: Whether or not to sync to disk + * + * Called either from qed_check or with table_lock held. */ static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, unsigned int index, unsigned int n, bool flush) @@ -97,16 +104,20 @@ static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, /* Adjust for offset into table */ offset += start * sizeof(uint64_t); + if (qemu_in_coroutine()) { + qemu_co_mutex_unlock(&s->table_lock); + } ret = bdrv_pwritev(s->bs->file, offset, &qiov); + if (qemu_in_coroutine()) { + qemu_co_mutex_lock(&s->table_lock); + } trace_qed_write_table_cb(s, table, flush, ret); if (ret < 0) { goto out; } if (flush) { - qed_acquire(s); ret = bdrv_flush(s->bs); - qed_release(s); if (ret < 0) { goto out; } @@ -123,6 +134,7 @@ int qed_read_l1_table_sync(BDRVQEDState *s) return qed_read_table(s, s->header.l1_table_offset, s->l1_table); } +/* Called either from qed_check or with table_lock held. */ int qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n) { BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE); @@ -136,6 +148,7 @@ int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index, return qed_write_l1_table(s, index, n); } +/* Called either from qed_check or with table_lock held. */ int qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset) { int ret; @@ -154,7 +167,6 @@ int qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset) BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD); ret = qed_read_table(s, offset, request->l2_table->table); - qed_acquire(s); if (ret) { /* can't trust loaded L2 table anymore */ qed_unref_l2_cache_entry(request->l2_table); @@ -170,7 +182,6 @@ int qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset) request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset); assert(request->l2_table != NULL); } - qed_release(s); return ret; } @@ -180,6 +191,7 @@ int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset return qed_read_l2_table(s, request, offset); } +/* Called either from qed_check or with table_lock held. */ int qed_write_l2_table(BDRVQEDState *s, QEDRequest *request, unsigned int index, unsigned int n, bool flush) { -- cgit v1.2.3