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From: Kevin Wolf <kwolf@redhat.com>
To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com, stefanha@redhat.com
Subject: [Qemu-devel] [PATCH 10/20] qcow1: Handle failure for potentially large allocations
Date: Wed, 21 May 2014 18:28:08 +0200	[thread overview]
Message-ID: <1400689698-3096-11-git-send-email-kwolf@redhat.com> (raw)
In-Reply-To: <1400689698-3096-1-git-send-email-kwolf@redhat.com>

Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the qcow1 block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/block/qcow.c b/block/qcow.c
index 7fd57d7..ab73ad7 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -182,7 +182,12 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     s->l1_table_offset = header.l1_table_offset;
-    s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
+    s->l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t));
+    if (s->l1_table == NULL) {
+        error_setg(errp, "Could not allocate memory for L1 table");
+        ret = -ENOMEM;
+        goto fail;
+    }
 
     ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
                s->l1_size * sizeof(uint64_t));
@@ -193,8 +198,16 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
     for(i = 0;i < s->l1_size; i++) {
         be64_to_cpus(&s->l1_table[i]);
     }
-    /* alloc L2 cache */
-    s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
+
+    /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
+    s->l2_cache =
+        qemu_try_blockalign(bs->file,
+                            s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
+    if (s->l2_cache == NULL) {
+        error_setg(errp, "Could not allocate L2 table cache");
+        ret = -ENOMEM;
+        goto fail;
+    }
     s->cluster_cache = g_malloc(s->cluster_size);
     s->cluster_data = g_malloc(s->cluster_size);
     s->cluster_cache_offset = -1;
@@ -517,7 +530,10 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
     void *orig_buf;
 
     if (qiov->niov > 1) {
-        buf = orig_buf = qemu_blockalign(bs, qiov->size);
+        buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
+        if (buf == NULL) {
+            return -ENOMEM;
+        }
     } else {
         orig_buf = NULL;
         buf = (uint8_t *)qiov->iov->iov_base;
@@ -619,7 +635,10 @@ static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
     s->cluster_cache_offset = -1; /* disable compressed cache */
 
     if (qiov->niov > 1) {
-        buf = orig_buf = qemu_blockalign(bs, qiov->size);
+        buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
+        if (buf == NULL) {
+            return -ENOMEM;
+        }
         qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
     } else {
         orig_buf = NULL;
-- 
1.8.3.1

  parent reply	other threads:[~2014-05-21 16:28 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-21 16:27 [Qemu-devel] [PATCH 00/20] block: Handle failure for potentially large allocations Kevin Wolf
2014-05-21 16:27 ` [Qemu-devel] [PATCH 01/20] block: Introduce qemu_try_blockalign() Kevin Wolf
2014-05-22 15:50   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 02/20] block: Handle failure for potentially large allocations Kevin Wolf
2014-05-22 15:50   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 03/20] bochs: " Kevin Wolf
2014-05-22 15:52   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 04/20] cloop: " Kevin Wolf
2014-05-22 15:53   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 05/20] curl: " Kevin Wolf
2014-05-22 15:54   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 06/20] dmg: " Kevin Wolf
2014-05-22 15:55   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 07/20] iscsi: " Kevin Wolf
2014-05-21 20:26   ` Paolo Bonzini
2014-05-22 15:58   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 08/20] nfs: " Kevin Wolf
2014-05-22 16:00   ` Stefan Hajnoczi
2014-05-22 16:38   ` ronnie sahlberg
2014-05-21 16:28 ` [Qemu-devel] [PATCH 09/20] parallels: " Kevin Wolf
2014-05-22 16:01   ` Stefan Hajnoczi
2014-05-21 16:28 ` Kevin Wolf [this message]
2014-05-22 16:01   ` [Qemu-devel] [PATCH 10/20] qcow1: " Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 11/20] qcow2: " Kevin Wolf
2014-05-22 16:07   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 12/20] qed: " Kevin Wolf
2014-05-22 16:08   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 13/20] raw-posix: " Kevin Wolf
2014-05-22 16:08   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 14/20] raw-win32: " Kevin Wolf
2014-05-22 16:09   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 15/20] rbd: " Kevin Wolf
2014-05-22 16:10   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 16/20] vdi: " Kevin Wolf
2014-05-22 16:10   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 17/20] vhdx: " Kevin Wolf
2014-05-22 16:11   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 18/20] vmdk: " Kevin Wolf
2014-05-22 16:11   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 19/20] vpc: " Kevin Wolf
2014-05-22 16:11   ` Stefan Hajnoczi
2014-05-21 16:28 ` [Qemu-devel] [PATCH 20/20] mirror: " Kevin Wolf
2014-05-22 16:11   ` Stefan Hajnoczi

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