From 4a5025f224c53d2194e2f62cb730a1fef961ff45 Mon Sep 17 00:00:00 2001

Message-Id: <4a5025f224c53d2194e2f62cb730a1fef961ff45.1389014116.git.minovotn@redhat.com>

In-Reply-To: <c8cc35838d42aa286242772d97e3a9be7bb786ba.1389014116.git.minovotn@redhat.com>

References: <c8cc35838d42aa286242772d97e3a9be7bb786ba.1389014116.git.minovotn@redhat.com>

From: Paolo Bonzini <pbonzini@redhat.com>

Date: Mon, 9 Dec 2013 14:09:27 +0100

Subject: [PATCH 39/50] raw-posix: implement write_zeroes with MAY_UNMAP for

 files

RH-Author: Paolo Bonzini <pbonzini@redhat.com>

Message-id: <1386598178-11845-42-git-send-email-pbonzini@redhat.com>

Patchwork-id: 56078

O-Subject: [RHEL 7.0 qemu-kvm PATCH 41/52] raw-posix: implement write_zeroes with MAY_UNMAP for files

Bugzilla: 1007815

RH-Acked-by: Jeffrey Cody <jcody@redhat.com>

RH-Acked-by: Fam Zheng <famz@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Writing zeroes to a file can be done by punching a hole if

MAY_UNMAP is set.

Note that in this case ENOTSUP is not ignored, but makes

the block layer fall back to the generic implementation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

(cherry picked from commit 260a82e524b7f86c12b8e39d4c3f208af95645f7)

---

 block/raw-posix.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++--

 trace-events      |  1 +

 2 files changed, 65 insertions(+), 2 deletions(-)

Signed-off-by: Michal Novotny <minovotn@redhat.com>

---

 block/raw-posix.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++--

 trace-events      |  1 +

 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c

index 7a140b0..ca5bcb3 100644

--- a/block/raw-posix.c

+++ b/block/raw-posix.c

@@ -139,9 +139,10 @@ typedef struct BDRVRawState {

     void *aio_ctx;

 #endif

 #ifdef CONFIG_XFS

-    bool is_xfs : 1;

+    bool is_xfs:1;

 #endif

-    bool has_discard : 1;

+    bool has_discard:1;

+    bool discard_zeroes:1;

 } BDRVRawState;

 typedef struct BDRVRawReopenState {

@@ -283,6 +284,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,

     Error *local_err = NULL;

     const char *filename;

     int fd, ret;

+    struct stat st;

     opts = qemu_opts_create_nofail(&raw_runtime_opts);

     qemu_opts_absorb_qdict(opts, options, &local_err);

@@ -325,6 +327,15 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,

 #endif

     s->has_discard = true;

+

+    if (fstat(s->fd, &st) < 0) {

+        error_setg_errno(errp, errno, "Could not stat file");

+        goto fail;

+    }

+    if (S_ISREG(st.st_mode)) {

+        s->discard_zeroes = true;

+    }

+

 #ifdef CONFIG_XFS

     if (platform_test_xfs_fd(s->fd)) {

         s->is_xfs = true;

@@ -788,6 +799,29 @@ static int aio_worker(void *arg)

     return ret;

 }

+static int paio_submit_co(BlockDriverState *bs, int fd,

+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

+        int type)

+{

+    RawPosixAIOData *acb = g_slice_new(RawPosixAIOData);

+    ThreadPool *pool;

+

+    acb->bs = bs;

+    acb->aio_type = type;

+    acb->aio_fildes = fd;

+

+    if (qiov) {

+        acb->aio_iov = qiov->iov;

+        acb->aio_niov = qiov->niov;

+    }

+    acb->aio_nbytes = nb_sectors * 512;

+    acb->aio_offset = sector_num * 512;

+

+    trace_paio_submit_co(sector_num, nb_sectors, type);

+    pool = aio_get_thread_pool(bdrv_get_aio_context(bs));

+    return thread_pool_submit_co(pool, aio_worker, acb);

+}

+

 static BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,

         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

         BlockDriverCompletionFunc *cb, void *opaque, int type)

@@ -1200,6 +1234,31 @@ static coroutine_fn BlockDriverAIOCB *raw_aio_discard(BlockDriverState *bs,

                        cb, opaque, QEMU_AIO_DISCARD);

 }

+static int coroutine_fn raw_co_write_zeroes(

+    BlockDriverState *bs, int64_t sector_num,

+    int nb_sectors, BdrvRequestFlags flags)

+{

+    BDRVRawState *s = bs->opaque;

+

+    if (!(flags & BDRV_REQ_MAY_UNMAP)) {

+        return -ENOTSUP;

+    }

+    if (!s->discard_zeroes) {

+        return -ENOTSUP;

+    }

+    return paio_submit_co(bs, s->fd, sector_num, NULL, nb_sectors,

+                          QEMU_AIO_DISCARD);

+}

+

+static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)

+{

+    BDRVRawState *s = bs->opaque;

+

+    bdi->unallocated_blocks_are_zero = s->discard_zeroes;

+    bdi->can_write_zeroes_with_unmap = s->discard_zeroes;

+    return 0;

+}

+

 static QEMUOptionParameter raw_create_options[] = {

     {

         .name = BLOCK_OPT_SIZE,

@@ -1222,6 +1281,7 @@ static BlockDriver bdrv_file = {

     .bdrv_create = raw_create,

     .bdrv_has_zero_init = bdrv_has_zero_init_1,

     .bdrv_co_get_block_status = raw_co_get_block_status,

+    .bdrv_co_write_zeroes = raw_co_write_zeroes,

     .bdrv_aio_readv = raw_aio_readv,

     .bdrv_aio_writev = raw_aio_writev,

@@ -1230,6 +1290,7 @@ static BlockDriver bdrv_file = {

     .bdrv_truncate = raw_truncate,

     .bdrv_getlength = raw_getlength,

+    .bdrv_get_info = raw_get_info,

     .bdrv_get_allocated_file_size

                         = raw_get_allocated_file_size,

@@ -1584,6 +1645,7 @@ static BlockDriver bdrv_host_device = {

     .bdrv_truncate      = raw_truncate,

     .bdrv_getlength	= raw_getlength,

+    .bdrv_get_info = raw_get_info,

     .bdrv_get_allocated_file_size

                         = raw_get_allocated_file_size,

diff --git a/trace-events b/trace-events

index 40d4312..e9ee94f 100644

--- a/trace-events

+++ b/trace-events

@@ -120,6 +120,7 @@ thread_pool_cancel(void *req, void *opaque) "req %p opaque %p"

 # block/raw-win32.c

 # block/raw-posix.c

+paio_submit_co(int64_t sector_num, int nb_sectors, int type) "sector_num %"PRId64" nb_sectors %d type %d"

 paio_submit(void *acb, void *opaque, int64_t sector_num, int nb_sectors, int type) "acb %p opaque %p sector_num %"PRId64" nb_sectors %d type %d"

 # ioport.c

-- 

1.7.11.7