block: Add "file" output parameter to block status query functions

The added parameter can be used to return the BDS pointer which the
valid offset is referring to. Its value should be ignored unless
BDRV_BLOCK_OFFSET_VALID in ret is set.

Until block drivers fill in the right value, let's clear it explicitly
right before calling .bdrv_get_block_status.

The "bs->file" condition in bdrv_co_get_block_status is kept now to keep iotest
case 102 passing, and will be fixed once all drivers return the right file
pointer.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1453780743-16806-2-git-send-email-famz@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

17 files changed, 66 insertions, 35 deletions

diff --git a/block/io.c b/block/io.c
index 5bb353a8ca..ea040bef22 100644
--- a/block/io.c
+++ b/block/io.c
@@ -664,6 +664,7 @@ int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
 int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
 {
     int64_t target_sectors, ret, nb_sectors, sector_num = 0;
+    BlockDriverState *file;
     int n;
 
     target_sectors = bdrv_nb_sectors(bs);
@@ -676,7 +677,7 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
         if (nb_sectors <= 0) {
             return 0;
         }
-        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n);
+        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &file);
         if (ret < 0) {
             error_report("error getting block status at sector %" PRId64 ": %s",
                          sector_num, strerror(-ret));
@@ -1466,6 +1467,7 @@ int bdrv_flush_all(void)
 typedef struct BdrvCoGetBlockStatusData {
     BlockDriverState *bs;
     BlockDriverState *base;
+    BlockDriverState **file;
     int64_t sector_num;
     int nb_sectors;
     int *pnum;
@@ -1487,10 +1489,14 @@ typedef struct BdrvCoGetBlockStatusData {
  *
  * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes
  * beyond the end of the disk image it will be clamped.
+ *
+ * If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, 'file'
+ * points to the BDS which the sector range is allocated in.
  */
 static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
                                                      int64_t sector_num,
-                                                     int nb_sectors, int *pnum)
+                                                     int nb_sectors, int *pnum,
+                                                     BlockDriverState **file)
 {
     int64_t total_sectors;
     int64_t n;
@@ -1520,7 +1526,9 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
         return ret;
     }
 
-    ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
+    *file = NULL;
+    ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum,
+                                            file);
     if (ret < 0) {
         *pnum = 0;
         return ret;
@@ -1529,7 +1537,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
     if (ret & BDRV_BLOCK_RAW) {
         assert(ret & BDRV_BLOCK_OFFSET_VALID);
         return bdrv_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS,
-                                     *pnum, pnum);
+                                     *pnum, pnum, file);
     }
 
     if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
@@ -1549,10 +1557,11 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
     if (bs->file &&
         (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
         (ret & BDRV_BLOCK_OFFSET_VALID)) {
+        BlockDriverState *file2;
         int file_pnum;
 
         ret2 = bdrv_co_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS,
-                                        *pnum, &file_pnum);
+                                        *pnum, &file_pnum, &file2);
         if (ret2 >= 0) {
             /* Ignore errors.  This is just providing extra information, it
              * is useful but not necessary.
@@ -1577,14 +1586,15 @@ static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,
         BlockDriverState *base,
         int64_t sector_num,
         int nb_sectors,
-        int *pnum)
+        int *pnum,
+        BlockDriverState **file)
 {
     BlockDriverState *p;
     int64_t ret = 0;
 
     assert(bs != base);
     for (p = bs; p != base; p = backing_bs(p)) {
-        ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum);
+        ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum, file);
         if (ret < 0 || ret & BDRV_BLOCK_ALLOCATED) {
             break;
         }
@@ -1603,7 +1613,8 @@ static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque)
     data->ret = bdrv_co_get_block_status_above(data->bs, data->base,
                                                data->sector_num,
                                                data->nb_sectors,
-                                               data->pnum);
+                                               data->pnum,
+                                               data->file);
     data->done = true;
 }
 
@@ -1615,12 +1626,14 @@ static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque)
 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
                                     BlockDriverState *base,
                                     int64_t sector_num,
-                                    int nb_sectors, int *pnum)
+                                    int nb_sectors, int *pnum,
+                                    BlockDriverState **file)
 {
     Coroutine *co;
     BdrvCoGetBlockStatusData data = {
         .bs = bs,
         .base = base,
+        .file = file,
         .sector_num = sector_num,
         .nb_sectors = nb_sectors,
         .pnum = pnum,
@@ -1644,16 +1657,19 @@ int64_t bdrv_get_block_status_above(BlockDriverState *bs,
 
 int64_t bdrv_get_block_status(BlockDriverState *bs,
                               int64_t sector_num,
-                              int nb_sectors, int *pnum)
+                              int nb_sectors, int *pnum,
+                              BlockDriverState **file)
 {
     return bdrv_get_block_status_above(bs, backing_bs(bs),
-                                       sector_num, nb_sectors, pnum);
+                                       sector_num, nb_sectors, pnum, file);
 }
 
 int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
                                    int nb_sectors, int *pnum)
 {
-    int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
+    BlockDriverState *file;
+    int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum,
+                                        &file);
     if (ret < 0) {
         return ret;
     }
diff --git a/block/iscsi.c b/block/iscsi.c
index bffd707b8b..e182557cfc 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -532,7 +532,8 @@ static bool iscsi_allocationmap_is_allocated(IscsiLun *iscsilun,
 
 static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
                                                   int64_t sector_num,
-                                                  int nb_sectors, int *pnum)
+                                                  int nb_sectors, int *pnum,
+                                                  BlockDriverState **file)
 {
     IscsiLun *iscsilun = bs->opaque;
     struct scsi_get_lba_status *lbas = NULL;
@@ -650,7 +651,8 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
         !iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
         int64_t ret;
         int pnum;
-        ret = iscsi_co_get_block_status(bs, sector_num, INT_MAX, &pnum);
+        BlockDriverState *file;
+        ret = iscsi_co_get_block_status(bs, sector_num, INT_MAX, &pnum, &file);
         if (ret < 0) {
             return ret;
         }
diff --git a/block/mirror.c b/block/mirror.c
index e9e151c341..2c0edfaf48 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -168,6 +168,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
     MirrorOp *op;
     int pnum;
     int64_t ret;
+    BlockDriverState *file;
 
     max_iov = MIN(source->bl.max_iov, s->target->bl.max_iov);
 
@@ -306,7 +307,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
     trace_mirror_one_iteration(s, sector_num, nb_sectors);
 
     ret = bdrv_get_block_status_above(source, NULL, sector_num,
-                                      nb_sectors, &pnum);
+                                      nb_sectors, &pnum, &file);
     if (ret < 0 || pnum < nb_sectors ||
             (ret & BDRV_BLOCK_DATA && !(ret & BDRV_BLOCK_ZERO))) {
         bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors,
diff --git a/block/parallels.c b/block/parallels.c
index ee390815dc..e2de308efa 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -261,7 +261,7 @@ static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 
 
 static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     BDRVParallelsState *s = bs->opaque;
     int64_t offset;
diff --git a/block/qcow.c b/block/qcow.c
index afed18fe98..4202797a11 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -489,7 +489,7 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
 }
 
 static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     BDRVQcowState *s = bs->opaque;
     int index_in_cluster, n;
diff --git a/block/qcow2.c b/block/qcow2.c
index fd8436c5f8..d4ea6b416d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1330,7 +1330,7 @@ static void qcow2_join_options(QDict *options, QDict *old_options)
 }
 
 static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     BDRVQcow2State *s = bs->opaque;
     uint64_t cluster_offset;
diff --git a/block/qed.c b/block/qed.c
index 0c870cd90f..8f6f8415d6 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -725,7 +725,8 @@ static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t l
 
 static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs,
                                                  int64_t sector_num,
-                                                 int nb_sectors, int *pnum)
+                                                 int nb_sectors, int *pnum,
+                                                 BlockDriverState **file)
 {
     BDRVQEDState *s = bs->opaque;
     size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE;
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 6df3067ddf..3ef9b256f8 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1818,7 +1818,8 @@ static int find_allocation(BlockDriverState *bs, off_t start,
  */
 static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
                                                     int64_t sector_num,
-                                                    int nb_sectors, int *pnum)
+                                                    int nb_sectors, int *pnum,
+                                                    BlockDriverState **file)
 {
     off_t start, data = 0, hole = 0;
     int64_t total_size;
diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index bcaee115e1..9a8933b211 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -115,7 +115,8 @@ fail:
 
 static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
                                             int64_t sector_num,
-                                            int nb_sectors, int *pnum)
+                                            int nb_sectors, int *pnum,
+                                            BlockDriverState **file)
 {
     *pnum = nb_sectors;
     return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
diff --git a/block/sheepdog.c b/block/sheepdog.c
index ff89298b13..2ea05a6e28 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2708,7 +2708,7 @@ retry:
 
 static coroutine_fn int64_t
 sd_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
-                       int *pnum)
+                       int *pnum, BlockDriverState **file)
 {
     BDRVSheepdogState *s = bs->opaque;
     SheepdogInode *inode = &s->inode;
diff --git a/block/vdi.c b/block/vdi.c
index 61bcd54575..294c43877a 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -527,7 +527,7 @@ static int vdi_reopen_prepare(BDRVReopenState *state,
 }
 
 static int64_t coroutine_fn vdi_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */
     BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
diff --git a/block/vmdk.c b/block/vmdk.c
index 4a5850bcf0..109fd5f729 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1261,7 +1261,7 @@ static inline uint64_t vmdk_find_index_in_cluster(VmdkExtent *extent,
 }
 
 static int64_t coroutine_fn vmdk_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     BDRVVmdkState *s = bs->opaque;
     int64_t index_in_cluster, n, ret;
diff --git a/block/vpc.c b/block/vpc.c
index d852f966a0..a0703074f8 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -579,7 +579,7 @@ static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num,
 }
 
 static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum)
+        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
 {
     BDRVVPCState *s = bs->opaque;
     VHDFooter *footer = (VHDFooter*) s->footer_buf;
diff --git a/block/vvfat.c b/block/vvfat.c
index 2ea5a4ab0b..b8d29e17cd 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -2884,7 +2884,7 @@ static coroutine_fn int vvfat_co_write(BlockDriverState *bs, int64_t sector_num,
 }
 
 static int64_t coroutine_fn vvfat_co_get_block_status(BlockDriverState *bs,
-	int64_t sector_num, int nb_sectors, int* n)
+	int64_t sector_num, int nb_sectors, int *n, BlockDriverState **file)
 {
     BDRVVVFATState* s = bs->opaque;
     *n = s->sector_count - sector_num;
diff --git a/include/block/block.h b/include/block/block.h
index 4452b79dd4..0035ad8ea8 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -111,9 +111,10 @@ typedef struct HDGeometry {
 
 /*
  * Allocation status flags
- * BDRV_BLOCK_DATA: data is read from bs->file or another file
+ * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
  * BDRV_BLOCK_ZERO: sectors read as zero
- * BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
+ * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
+ *                          bdrv_get_block_status.
  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
  *                       layer (as opposed to the backing file)
  * BDRV_BLOCK_RAW: used internally to indicate that the request
@@ -384,11 +385,13 @@ int bdrv_has_zero_init(BlockDriverState *bs);
 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
-                              int nb_sectors, int *pnum);
+                              int nb_sectors, int *pnum,
+                              BlockDriverState **file);
 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
                                     BlockDriverState *base,
                                     int64_t sector_num,
-                                    int nb_sectors, int *pnum);
+                                    int nb_sectors, int *pnum,
+                                    BlockDriverState **file);
 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
                       int *pnum);
 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index dd00d12a6f..9ef823a660 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -166,7 +166,8 @@ struct BlockDriver {
     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors);
     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum);
+        int64_t sector_num, int nb_sectors, int *pnum,
+        BlockDriverState **file);
 
     /*
      * Invalidate any cached meta-data.
diff --git a/qemu-img.c b/qemu-img.c
index 33e451c101..e653b2f304 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1072,13 +1072,15 @@ static int img_compare(int argc, char **argv)
 
     for (;;) {
         int64_t status1, status2;
+        BlockDriverState *file;
+
         nb_sectors = sectors_to_process(total_sectors, sector_num);
         if (nb_sectors <= 0) {
             break;
         }
         status1 = bdrv_get_block_status_above(bs1, NULL, sector_num,
                                               total_sectors1 - sector_num,
-                                              &pnum1);
+                                              &pnum1, &file);
         if (status1 < 0) {
             ret = 3;
             error_report("Sector allocation test failed for %s", filename1);
@@ -1088,7 +1090,7 @@ static int img_compare(int argc, char **argv)
 
         status2 = bdrv_get_block_status_above(bs2, NULL, sector_num,
                                               total_sectors2 - sector_num,
-                                              &pnum2);
+                                              &pnum2, &file);
         if (status2 < 0) {
             ret = 3;
             error_report("Sector allocation test failed for %s", filename2);
@@ -1271,9 +1273,10 @@ static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num)
     n = MIN(s->total_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
 
     if (s->sector_next_status <= sector_num) {
+        BlockDriverState *file;
         ret = bdrv_get_block_status(blk_bs(s->src[s->src_cur]),
                                     sector_num - s->src_cur_offset,
-                                    n, &n);
+                                    n, &n, &file);
         if (ret < 0) {
             return ret;
         }
@@ -2201,6 +2204,7 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num,
 {
     int64_t ret;
     int depth;
+    BlockDriverState *file;
 
     /* As an optimization, we could cache the current range of unallocated
      * clusters in each file of the chain, and avoid querying the same
@@ -2209,7 +2213,8 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num,
 
     depth = 0;
     for (;;) {
-        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors);
+        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors,
+                                    &file);
         if (ret < 0) {
             return ret;
         }