From: Cole Robinson <crobinso@redhat.com>

Date: Thu, 24 Oct 2019 11:32:46 -0400

Subject: [PATCH] Revert "block: avoid recursive block_status call if possible"

This reverts commit 69f47505ee66afaa513305de0c1895a224e52c45.

Workaround for qcow2 triggered XFS corruption, bug 1763519

---

 block/io.c                 |  9 +--------

 block/qcow2-refcount.c     | 32 --------------------------------

 block/qcow2.c              | 11 -----------

 block/qcow2.h              |  4 ----

 include/block/block.h      |  8 +-------

 tests/qemu-iotests/102     |  2 +-

 tests/qemu-iotests/102.out |  3 +--

 tests/qemu-iotests/141.out |  2 +-

 tests/qemu-iotests/144.out |  2 +-

 9 files changed, 6 insertions(+), 67 deletions(-)

diff --git a/block/io.c b/block/io.c

index 06305c6ea6..ef057ba5db 100644

--- a/block/io.c

+++ b/block/io.c

@@ -2156,12 +2156,6 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,

      */

     assert(*pnum && QEMU_IS_ALIGNED(*pnum, align) &&

            align > offset - aligned_offset);

-    if (ret & BDRV_BLOCK_RECURSE) {

-        assert(ret & BDRV_BLOCK_DATA);

-        assert(ret & BDRV_BLOCK_OFFSET_VALID);

-        assert(!(ret & BDRV_BLOCK_ZERO));

-    }

-

     *pnum -= offset - aligned_offset;

     if (*pnum > bytes) {

         *pnum = bytes;

@@ -2192,8 +2186,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,

         }

     }

-    if (want_zero && ret & BDRV_BLOCK_RECURSE &&

-        local_file && local_file != bs &&

+    if (want_zero && local_file && local_file != bs &&

         (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&

         (ret & BDRV_BLOCK_OFFSET_VALID)) {

         int64_t file_pnum;

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c

index ef965d7895..81ecb88f9c 100644

--- a/block/qcow2-refcount.c

+++ b/block/qcow2-refcount.c

@@ -3448,35 +3448,3 @@ int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size)

                             "There are no references in the refcount table.");

     return -EIO;

 }

-

-int qcow2_detect_metadata_preallocation(BlockDriverState *bs)

-{

-    BDRVQcow2State *s = bs->opaque;

-    int64_t i, end_cluster, cluster_count = 0, threshold;

-    int64_t file_length, real_allocation, real_clusters;

-

-    file_length = bdrv_getlength(bs->file->bs);

-    if (file_length < 0) {

-        return file_length;

-    }

-

-    real_allocation = bdrv_get_allocated_file_size(bs->file->bs);

-    if (real_allocation < 0) {

-        return real_allocation;

-    }

-

-    real_clusters = real_allocation / s->cluster_size;

-    threshold = MAX(real_clusters * 10 / 9, real_clusters + 2);

-

-    end_cluster = size_to_clusters(s, file_length);

-    for (i = 0; i < end_cluster && cluster_count < threshold; i++) {

-        uint64_t refcount;

-        int ret = qcow2_get_refcount(bs, i, &refcount);

-        if (ret < 0) {

-            return ret;

-        }

-        cluster_count += !!refcount;

-    }

-

-    return cluster_count >= threshold;

-}

diff --git a/block/qcow2.c b/block/qcow2.c

index 039bdc2f7e..86e88f6af4 100644

--- a/block/qcow2.c

+++ b/block/qcow2.c

@@ -1895,12 +1895,6 @@ static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,

     unsigned int bytes;

     int status = 0;

-    if (!s->metadata_preallocation_checked) {

-        ret = qcow2_detect_metadata_preallocation(bs);

-        s->metadata_preallocation = (ret == 1);

-        s->metadata_preallocation_checked = true;

-    }

-

     bytes = MIN(INT_MAX, count);

     qemu_co_mutex_lock(&s->lock);

     ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset);

@@ -1923,11 +1917,6 @@ static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,

     } else if (ret != QCOW2_CLUSTER_UNALLOCATED) {

         status |= BDRV_BLOCK_DATA;

     }

-    if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) &&

-        (status & BDRV_BLOCK_OFFSET_VALID))

-    {

-        status |= BDRV_BLOCK_RECURSE;

-    }

     return status;

 }

diff --git a/block/qcow2.h b/block/qcow2.h

index fc1b0d3c1e..567375e56c 100644

--- a/block/qcow2.h

+++ b/block/qcow2.h

@@ -356,9 +356,6 @@ typedef struct BDRVQcow2State {

     int nb_threads;

     BdrvChild *data_file;

-

-    bool metadata_preallocation_checked;

-    bool metadata_preallocation;

 } BDRVQcow2State;

 typedef struct Qcow2COWRegion {

@@ -658,7 +655,6 @@ int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,

                                 void *cb_opaque, Error **errp);

 int qcow2_shrink_reftable(BlockDriverState *bs);

 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);

-int qcow2_detect_metadata_preallocation(BlockDriverState *bs);

 /* qcow2-cluster.c functions */

 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,

diff --git a/include/block/block.h b/include/block/block.h

index 50a07c1c33..269c0931e7 100644

--- a/include/block/block.h

+++ b/include/block/block.h

@@ -156,15 +156,10 @@ typedef struct HDGeometry {

  * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this

  *                 layer, set by block layer

  *

- * Internal flags:

+ * Internal flag:

  * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request

  *                 that the block layer recompute the answer from the returned

  *                 BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.

- * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for

- *                     zeroes in file child of current block node inside

- *                     returned region. Only valid together with both

- *                     BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not

- *                     appear with BDRV_BLOCK_ZERO.

  *

  * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the

  * host offset within the returned BDS that is allocated for the

@@ -189,7 +184,6 @@ typedef struct HDGeometry {

 #define BDRV_BLOCK_RAW          0x08

 #define BDRV_BLOCK_ALLOCATED    0x10

 #define BDRV_BLOCK_EOF          0x20

-#define BDRV_BLOCK_RECURSE      0x40

 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK

 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;

diff --git a/tests/qemu-iotests/102 b/tests/qemu-iotests/102

index b898df436f..749ff66b8a 100755

--- a/tests/qemu-iotests/102

+++ b/tests/qemu-iotests/102

@@ -55,7 +55,7 @@ $QEMU_IO -c 'write 0 64k' "$TEST_IMG" | _filter_qemu_io

 $QEMU_IMG resize -f raw --shrink "$TEST_IMG" $((5 * 64 * 1024))

 $QEMU_IO -c map "$TEST_IMG"

-$QEMU_IMG map "$TEST_IMG" | _filter_qemu_img_map

+$QEMU_IMG map "$TEST_IMG"

 echo

 echo '=== Testing map on an image file truncated outside of qemu ==='

diff --git a/tests/qemu-iotests/102.out b/tests/qemu-iotests/102.out

index cd2fdc7f96..4401b08fee 100644

--- a/tests/qemu-iotests/102.out

+++ b/tests/qemu-iotests/102.out

@@ -7,8 +7,7 @@ wrote 65536/65536 bytes at offset 0

 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

 Image resized.

 64 KiB (0x10000) bytes     allocated at offset 0 bytes (0x0)

-Offset          Length          File

-0               0x10000         TEST_DIR/t.IMGFMT

+Offset          Length          Mapped to       File

 === Testing map on an image file truncated outside of qemu ===

diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out

index 4d71d9dcae..41c7291258 100644

--- a/tests/qemu-iotests/141.out

+++ b/tests/qemu-iotests/141.out

@@ -42,9 +42,9 @@ Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.

 {"return": {}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}

-{"return": {}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "ready", "id": "job0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "job0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}

+{"return": {}}

 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: commit"}}

 {"return": {}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}

diff --git a/tests/qemu-iotests/144.out b/tests/qemu-iotests/144.out

index a9a8216bea..55299201e4 100644

--- a/tests/qemu-iotests/144.out

+++ b/tests/qemu-iotests/144.out

@@ -14,10 +14,10 @@ Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "virtio0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "virtio0"}}

-{"return": {}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "ready", "id": "virtio0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}

 {"return": {}}

+{"return": {}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "virtio0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "virtio0"}}

 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}