[Qemu-devel] [PATCH v4 15/16] block: Remove "growable" from BDS

[Max Reitz <mreitz@redhat.com>]

Now that request clamping is done in the BlockBackend, the "growable"
field can be removed from the BlockDriverState. All BDSs are now treated
as being "growable" (that is, they are allowed to grow; they are not
necessarily actually able to).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c                   | 24 +++++++-----------------
 block/qcow2.c             |  6 ------
 block/raw-posix.c         |  2 +-
 block/raw-win32.c         |  2 +-
 block/sheepdog.c          |  2 +-
 include/block/block_int.h |  3 ---
 6 files changed, 10 insertions(+), 29 deletions(-)

diff --git a/block.c b/block.c
index 84f801f..47468a5 100644
--- a/block.c
+++ b/block.c
@@ -972,7 +972,6 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     bs->zero_beyond_eof = true;
     open_flags = bdrv_open_flags(bs, flags);
     bs->read_only = !(open_flags & BDRV_O_RDWR);
-    bs->growable = !!(flags & BDRV_O_PROTOCOL);
 
     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
         error_setg(errp,
@@ -1886,7 +1885,6 @@ void bdrv_close(BlockDriverState *bs)
         bs->encrypted = 0;
         bs->valid_key = 0;
         bs->sg = 0;
-        bs->growable = 0;
         bs->zero_beyond_eof = false;
         QDECREF(bs->options);
         bs->options = NULL;
@@ -2646,25 +2644,17 @@ exit:
 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
                                    size_t size)
 {
-    int64_t len;
-
     if (size > INT_MAX) {
         return -EIO;
     }
 
-    if (!bdrv_is_inserted(bs))
+    if (!bdrv_is_inserted(bs)) {
         return -ENOMEDIUM;
+    }
 
-    if (bs->growable)
-        return 0;
-
-    len = bdrv_getlength(bs);
-
-    if (offset < 0)
-        return -EIO;
-
-    if ((offset > len) || (len - offset < size))
+    if (offset < 0) {
         return -EIO;
+    }
 
     return 0;
 }
@@ -3046,10 +3036,10 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
     }
 
     /* Forward the request to the BlockDriver */
-    if (!(bs->zero_beyond_eof && bs->growable)) {
+    if (!bs->zero_beyond_eof) {
         ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
     } else {
-        /* Read zeros after EOF of growable BDSes */
+        /* Read zeros after EOF */
         int64_t total_sectors, max_nb_sectors;
 
         total_sectors = bdrv_nb_sectors(bs);
@@ -3326,7 +3316,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
 
-    if (bs->growable && ret >= 0) {
+    if (ret >= 0) {
         bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
     }
 
diff --git a/block/qcow2.c b/block/qcow2.c
index 7e614d7..2ed8d95 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2521,15 +2521,12 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
 {
     BDRVQcowState *s = bs->opaque;
     int64_t total_sectors = bs->total_sectors;
-    int growable = bs->growable;
     bool zero_beyond_eof = bs->zero_beyond_eof;
     int ret;
 
     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
-    bs->growable = 1;
     bs->zero_beyond_eof = false;
     ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov);
-    bs->growable = growable;
     bs->zero_beyond_eof = zero_beyond_eof;
 
     /* bdrv_co_do_writev will have increased the total_sectors value to include
@@ -2544,15 +2541,12 @@ static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                               int64_t pos, int size)
 {
     BDRVQcowState *s = bs->opaque;
-    int growable = bs->growable;
     bool zero_beyond_eof = bs->zero_beyond_eof;
     int ret;
 
     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
-    bs->growable = 1;
     bs->zero_beyond_eof = false;
     ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size);
-    bs->growable = growable;
     bs->zero_beyond_eof = zero_beyond_eof;
 
     return ret;
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 7b42f37..4c1326c 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1047,7 +1047,7 @@ static int aio_worker(void *arg)
     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
     case QEMU_AIO_READ:
         ret = handle_aiocb_rw(aiocb);
-        if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->bs->growable) {
+        if (ret >= 0 && ret < aiocb->aio_nbytes) {
             iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret,
                       0, aiocb->aio_nbytes - ret);
 
diff --git a/block/raw-win32.c b/block/raw-win32.c
index 06243d7..dae5d2f 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -101,7 +101,7 @@ static int aio_worker(void *arg)
     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
     case QEMU_AIO_READ:
         count = handle_aiocb_rw(aiocb);
-        if (count < aiocb->aio_nbytes && aiocb->bs->growable) {
+        if (count < aiocb->aio_nbytes) {
             /* A short read means that we have reached EOF. Pad the buffer
              * with zeros for bytes after EOF. */
             iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
diff --git a/block/sheepdog.c b/block/sheepdog.c
index e9b0ca1..b320871 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2117,7 +2117,7 @@ static coroutine_fn int sd_co_writev(BlockDriverState *bs, int64_t sector_num,
     int64_t offset = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE;
     BDRVSheepdogState *s = bs->opaque;
 
-    if (bs->growable && offset > s->inode.vdi_size) {
+    if (offset > s->inode.vdi_size) {
         ret = sd_truncate(bs, offset);
         if (ret < 0) {
             return ret;
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7ad1950..b340e7e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -369,9 +369,6 @@ struct BlockDriverState {
     /* I/O Limits */
     BlockLimits bl;
 
-    /* Whether the disk can expand beyond total_sectors */
-    int growable;
-
     /* Whether produces zeros when read beyond eof */
     bool zero_beyond_eof;
 
-- 
2.1.0