block: Remove "growable" from BDS

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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-16-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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 > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
         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;
 }
@@ -3043,10 +3033,10 @@ 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);
@@ -3323,7 +3313,7 @@ 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);
     }
 

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;

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);
 

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,

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;

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;