block: Expand block status mode from bool to flags

This patch is purely mechanical, changing bool want_zero into an
unsigned int for bitwise-or of flags.  As of this patch, all
implementations are unchanged (the old want_zero==true is now
mode==BDRV_WANT_PRECISE which is a superset of BDRV_WANT_ZERO); but
the callers in io.c that used to pass want_zero==false are now
prepared for future driver changes that can now distinguish bewteen
BDRV_WANT_ZERO vs. BDRV_WANT_ALLOCATED.  The next patch will actually
change the file-posix driver along those lines, now that we have
more-specific hints.

As for the background why this patch is useful: right now, the
file-posix driver recognizes that if allocation is being queried, the
entire image can be reported as allocated (there is no backing file to
refer to) - but this throws away information on whether the entire
image reads as zero (trivially true if lseek(SEEK_HOLE) at offset 0
returns -ENXIO, a bit more complicated to prove if the raw file was
created with 'qemu-img create' since we intentionally allocate a small
chunk of all-zero data to help with alignment probing).  Later patches
will add a generic algorithm for seeing if an entire file reads as
zeroes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20250509204341.3553601-16-eblake@redhat.com>

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 1c1967f8e0a3227313361263e4b6075924f24abc..c54aee0c84bf572e7223c9f6de7fa30ee984ff6e 100644 (file)
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -751,9 +751,9 @@ blkdebug_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-blkdebug_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
-                         int64_t bytes, int64_t *pnum, int64_t *map,
-                         BlockDriverState **file)
+blkdebug_co_block_status(BlockDriverState *bs, unsigned int mode,
+                         int64_t offset, int64_t bytes, int64_t *pnum,
+                         int64_t *map, BlockDriverState **file)
 {
     int err;
 

diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 00af0b18ac4f5b3d35d37771209757da9b4e39d2..36d5d3ed9b021f5eb84442c378ad3c30784c202c 100644 (file)
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -291,8 +291,8 @@ cbw_co_preadv_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-cbw_co_snapshot_block_status(BlockDriverState *bs,
-                             bool want_zero, int64_t offset, int64_t bytes,
+cbw_co_snapshot_block_status(BlockDriverState *bs, unsigned int mode,
+                             int64_t offset, int64_t bytes,
                              int64_t *pnum, int64_t *map,
                              BlockDriverState **file)
 {

diff --git a/block/coroutines.h b/block/coroutines.h
index 79e5efbf75286146eccde62d6aa425e7d2312ed4..892646bb7aaee479469ab17282d0444850919b67 100644 (file)
--- a/block/coroutines.h
+++ b/block/coroutines.h
@@ -47,7 +47,7 @@ int coroutine_fn GRAPH_RDLOCK
 bdrv_co_common_block_status_above(BlockDriverState *bs,
                                   BlockDriverState *base,
                                   bool include_base,
-                                  bool want_zero,
+                                  unsigned int mode,
                                   int64_t offset,
                                   int64_t bytes,
                                   int64_t *pnum,
@@ -78,7 +78,7 @@ int co_wrapper_mixed_bdrv_rdlock
 bdrv_common_block_status_above(BlockDriverState *bs,
                                BlockDriverState *base,
                                bool include_base,
-                               bool want_zero,
+                               unsigned int mode,
                                int64_t offset,
                                int64_t bytes,
                                int64_t *pnum,

diff --git a/block/file-posix.c b/block/file-posix.c
index ef52ed9169e17a82c21141635072e480aa544695..805a1a2949b9fa5a03ce10a48c8d49cbe5149eff 100644 (file)
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -3273,7 +3273,7 @@ static int find_allocation(BlockDriverState *bs, off_t start,
  * well exceed it.
  */
 static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
-                                            bool want_zero,
+                                            unsigned int mode,
                                             int64_t offset,
                                             int64_t bytes, int64_t *pnum,
                                             int64_t *map,
@@ -3289,7 +3289,7 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
         return ret;
     }
 
-    if (!want_zero) {
+    if (mode != BDRV_WANT_PRECISE) {
         *pnum = bytes;
         *map = offset;
         *file = bs;

diff --git a/block/gluster.c b/block/gluster.c
index 8712aa606a4bb97f7429aed24b7f2fdd5de7d792..1a2ef53e9b0389315c1e1776d2d4e1facc1fa71d 100644 (file)
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -1461,7 +1461,7 @@ exit:
  * (Based on raw_co_block_status() from file-posix.c.)
  */
 static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs,
-                                                     bool want_zero,
+                                                     unsigned int mode,
                                                      int64_t offset,
                                                      int64_t bytes,
                                                      int64_t *pnum,
@@ -1478,7 +1478,7 @@ static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs,
         return ret;
     }
 
-    if (!want_zero) {
+    if (mode != BDRV_WANT_PRECISE) {
         *pnum = bytes;
         *map = offset;
         *file = bs;

diff --git a/block/io.c b/block/io.c
index 6d98b0abb9803ea76659f00e6bcc9c81e3c1ad52..b5b143cd1b09ad432b57e246b0adf6b3bc198928 100644 (file)
--- a/block/io.c
+++ b/block/io.c
@@ -2364,10 +2364,8 @@ int bdrv_flush_all(void)
  * Drivers not implementing the functionality are assumed to not support
  * backing files, hence all their sectors are reported as allocated.
  *
- * If 'want_zero' is true, the caller is querying for mapping
- * purposes, with a focus on valid BDRV_BLOCK_OFFSET_VALID, _DATA, and
- * _ZERO where possible; otherwise, the result favors larger 'pnum',
- * with a focus on accurate BDRV_BLOCK_ALLOCATED.
+ * 'mode' serves as a hint as to which results are favored; see the
+ * BDRV_WANT_* macros for details.
  *
  * If 'offset' is beyond the end of the disk image the return value is
  * BDRV_BLOCK_EOF and 'pnum' is set to 0.
@@ -2387,7 +2385,7 @@ int bdrv_flush_all(void)
  * set to the host mapping and BDS corresponding to the guest offset.
  */
 static int coroutine_fn GRAPH_RDLOCK
-bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
+bdrv_co_do_block_status(BlockDriverState *bs, unsigned int mode,
                         int64_t offset, int64_t bytes,
                         int64_t *pnum, int64_t *map, BlockDriverState **file)
 {
@@ -2476,7 +2474,7 @@ bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
             local_file = bs;
             local_map = aligned_offset;
         } else {
-            ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset,
+            ret = bs->drv->bdrv_co_block_status(bs, mode, aligned_offset,
                                                 aligned_bytes, pnum, &local_map,
                                                 &local_file);
 
@@ -2488,10 +2486,10 @@ bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
              * the cache requires an RCU update, so double check here to avoid
              * such an update if possible.
              *
-             * Check want_zero, because we only want to update the cache when we
+             * Check mode, because we only want to update the cache when we
              * have accurate information about what is zero and what is data.
              */
-            if (want_zero &&
+            if (mode == BDRV_WANT_PRECISE &&
                 ret == (BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID) &&
                 QLIST_EMPTY(&bs->children))
             {
@@ -2548,7 +2546,7 @@ bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
 
     if (ret & BDRV_BLOCK_RAW) {
         assert(ret & BDRV_BLOCK_OFFSET_VALID && local_file);
-        ret = bdrv_co_do_block_status(local_file, want_zero, local_map,
+        ret = bdrv_co_do_block_status(local_file, mode, local_map,
                                       *pnum, pnum, &local_map, &local_file);
         goto out;
     }
@@ -2560,7 +2558,7 @@ bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
 
         if (!cow_bs) {
             ret |= BDRV_BLOCK_ZERO;
-        } else if (want_zero) {
+        } else if (mode == BDRV_WANT_PRECISE) {
             int64_t size2 = bdrv_co_getlength(cow_bs);
 
             if (size2 >= 0 && offset >= size2) {
@@ -2569,14 +2567,14 @@ bdrv_co_do_block_status(BlockDriverState *bs, bool want_zero,
         }
     }
 
-    if (want_zero && ret & BDRV_BLOCK_RECURSE &&
+    if (mode == BDRV_WANT_PRECISE && ret & BDRV_BLOCK_RECURSE &&
         local_file && local_file != bs &&
         (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
         (ret & BDRV_BLOCK_OFFSET_VALID)) {
         int64_t file_pnum;
         int ret2;
 
-        ret2 = bdrv_co_do_block_status(local_file, want_zero, local_map,
+        ret2 = bdrv_co_do_block_status(local_file, mode, local_map,
                                        *pnum, &file_pnum, NULL, NULL);
         if (ret2 >= 0) {
             /* Ignore errors.  This is just providing extra information, it
@@ -2627,7 +2625,7 @@ int coroutine_fn
 bdrv_co_common_block_status_above(BlockDriverState *bs,
                                   BlockDriverState *base,
                                   bool include_base,
-                                  bool want_zero,
+                                  unsigned int mode,
                                   int64_t offset,
                                   int64_t bytes,
                                   int64_t *pnum,
@@ -2654,7 +2652,7 @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
         return 0;
     }
 
-    ret = bdrv_co_do_block_status(bs, want_zero, offset, bytes, pnum,
+    ret = bdrv_co_do_block_status(bs, mode, offset, bytes, pnum,
                                   map, file);
     ++*depth;
     if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) {
@@ -2671,7 +2669,7 @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
     for (p = bdrv_filter_or_cow_bs(bs); include_base || p != base;
          p = bdrv_filter_or_cow_bs(p))
     {
-        ret = bdrv_co_do_block_status(p, want_zero, offset, bytes, pnum,
+        ret = bdrv_co_do_block_status(p, mode, offset, bytes, pnum,
                                       map, file);
         ++*depth;
         if (ret < 0) {
@@ -2734,7 +2732,8 @@ int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs,
                                             BlockDriverState **file)
 {
     IO_CODE();
-    return bdrv_co_common_block_status_above(bs, base, false, true, offset,
+    return bdrv_co_common_block_status_above(bs, base, false,
+                                             BDRV_WANT_PRECISE, offset,
                                              bytes, pnum, map, file, NULL);
 }
 
@@ -2765,8 +2764,9 @@ int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
         return 1;
     }
 
-    ret = bdrv_co_common_block_status_above(bs, NULL, false, false, offset,
-                                            bytes, &pnum, NULL, NULL, NULL);
+    ret = bdrv_co_common_block_status_above(bs, NULL, false, BDRV_WANT_ZERO,
+                                            offset, bytes, &pnum, NULL, NULL,
+                                            NULL);
 
     if (ret < 0) {
         return ret;
@@ -2782,9 +2782,9 @@ int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t offset,
     int64_t dummy;
     IO_CODE();
 
-    ret = bdrv_co_common_block_status_above(bs, bs, true, false, offset,
-                                            bytes, pnum ? pnum : &dummy, NULL,
-                                            NULL, NULL);
+    ret = bdrv_co_common_block_status_above(bs, bs, true, BDRV_WANT_ALLOCATED,
+                                            offset, bytes, pnum ? pnum : &dummy,
+                                            NULL, NULL, NULL);
     if (ret < 0) {
         return ret;
     }
@@ -2817,7 +2817,8 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *bs,
     int ret;
     IO_CODE();
 
-    ret = bdrv_co_common_block_status_above(bs, base, include_base, false,
+    ret = bdrv_co_common_block_status_above(bs, base, include_base,
+                                            BDRV_WANT_ALLOCATED,
                                             offset, bytes, pnum, NULL, NULL,
                                             &depth);
     if (ret < 0) {
@@ -3698,8 +3699,8 @@ bdrv_co_preadv_snapshot(BdrvChild *child, int64_t offset, int64_t bytes,
 }
 
 int coroutine_fn
-bdrv_co_snapshot_block_status(BlockDriverState *bs,
-                              bool want_zero, int64_t offset, int64_t bytes,
+bdrv_co_snapshot_block_status(BlockDriverState *bs, unsigned int mode,
+                              int64_t offset, int64_t bytes,
                               int64_t *pnum, int64_t *map,
                               BlockDriverState **file)
 {
@@ -3717,7 +3718,7 @@ bdrv_co_snapshot_block_status(BlockDriverState *bs,
     }
 
     bdrv_inc_in_flight(bs);
-    ret = drv->bdrv_co_snapshot_block_status(bs, want_zero, offset, bytes,
+    ret = drv->bdrv_co_snapshot_block_status(bs, mode, offset, bytes,
                                              pnum, map, file);
     bdrv_dec_in_flight(bs);
 

diff --git a/block/iscsi.c b/block/iscsi.c
index 2f0f4dac097b2b23e74f79f4eaf191f1c02b6a7e..15b96ee880061f4ecb9da44c4fa91dcd2c4fe433 100644 (file)
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -694,9 +694,9 @@ out_unlock:
 
 
 static int coroutine_fn iscsi_co_block_status(BlockDriverState *bs,
-                                              bool want_zero, int64_t offset,
-                                              int64_t bytes, int64_t *pnum,
-                                              int64_t *map,
+                                              unsigned int mode,
+                                              int64_t offset, int64_t bytes,
+                                              int64_t *pnum, int64_t *map,
                                               BlockDriverState **file)
 {
     IscsiLun *iscsilun = bs->opaque;

diff --git a/block/nbd.c b/block/nbd.c
index 887841bc813d867f4e569f103ff615ad55d46f8c..d5a2b21c6d14d7137bdd0295f055e10b061994f2 100644 (file)
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1397,8 +1397,8 @@ nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 }
 
 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_block_status(
-        BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes,
-        int64_t *pnum, int64_t *map, BlockDriverState **file)
+        BlockDriverState *bs, unsigned int mode, int64_t offset,
+        int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file)
 {
     int ret, request_ret;
     NBDExtent64 extent = { 0 };

diff --git a/block/null.c b/block/null.c
index dc0b1fdbd9b2a60e5a02c42662b688b62c287c6a..4e448d593d7364ea5bb062e7aee26d896c48f783 100644 (file)
--- a/block/null.c
+++ b/block/null.c
@@ -227,9 +227,9 @@ static int null_reopen_prepare(BDRVReopenState *reopen_state,
 }
 
 static int coroutine_fn null_co_block_status(BlockDriverState *bs,
-                                             bool want_zero, int64_t offset,
-                                             int64_t bytes, int64_t *pnum,
-                                             int64_t *map,
+                                             unsigned int mode,
+                                             int64_t offset, int64_t bytes,
+                                             int64_t *pnum, int64_t *map,
                                              BlockDriverState **file)
 {
     BDRVNullState *s = bs->opaque;

diff --git a/block/parallels.c b/block/parallels.c
index 347ca127f34439927ac728a1a68a9acc8f9e4bab..3a375e2a8aba01b57470a3ed20fb8a5ba3f450f9 100644 (file)
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -416,9 +416,9 @@ parallels_co_flush_to_os(BlockDriverState *bs)
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-parallels_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
-                          int64_t bytes, int64_t *pnum, int64_t *map,
-                          BlockDriverState **file)
+parallels_co_block_status(BlockDriverState *bs, unsigned int mode,
+                          int64_t offset, int64_t bytes, int64_t *pnum,
+                          int64_t *map, BlockDriverState **file)
 {
     BDRVParallelsState *s = bs->opaque;
     int count;

diff --git a/block/qcow.c b/block/qcow.c
index da8ad4d2430d727dc1a69292329e05f2d7d4b5c9..8a3e7591a929895bb35bfa728353ada79fa90338 100644 (file)
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -530,7 +530,7 @@ get_cluster_offset(BlockDriverState *bs, uint64_t offset, int allocate,
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-qcow_co_block_status(BlockDriverState *bs, bool want_zero,
+qcow_co_block_status(BlockDriverState *bs, unsigned int mode,
                      int64_t offset, int64_t bytes, int64_t *pnum,
                      int64_t *map, BlockDriverState **file)
 {

diff --git a/block/qcow2.c b/block/qcow2.c
index 7774e7f09098d45be28398940c903b219d2504a9..66fba89b414bf0d8ff74b722763dcb5a8338e2cc 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2141,9 +2141,9 @@ static void qcow2_join_options(QDict *options, QDict *old_options)
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
-                      int64_t count, int64_t *pnum, int64_t *map,
-                      BlockDriverState **file)
+qcow2_co_block_status(BlockDriverState *bs, unsigned int mode,
+                      int64_t offset, int64_t count, int64_t *pnum,
+                      int64_t *map, BlockDriverState **file)
 {
     BDRVQcow2State *s = bs->opaque;
     uint64_t host_offset;

diff --git a/block/qed.c b/block/qed.c
index ac24449ffb3f4e1b25bcff9ba2283933e383ff70..4a36fb39294c8a2f46e824355e81a562b8cc2f45 100644 (file)
--- a/block/qed.c
+++ b/block/qed.c
@@ -833,9 +833,9 @@ fail:
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-bdrv_qed_co_block_status(BlockDriverState *bs, bool want_zero, int64_t pos,
-                         int64_t bytes, int64_t *pnum, int64_t *map,
-                         BlockDriverState **file)
+bdrv_qed_co_block_status(BlockDriverState *bs, unsigned int mode,
+                         int64_t pos, int64_t bytes, int64_t *pnum,
+                         int64_t *map, BlockDriverState **file)
 {
     BDRVQEDState *s = bs->opaque;
     size_t len = MIN(bytes, SIZE_MAX);

diff --git a/block/quorum.c b/block/quorum.c
index 30747a6df9376f821c6b18beff6067dbd6375cbc..ed8ce801ee3475c77bb618725daf13f4ed19b76d 100644 (file)
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -1226,7 +1226,7 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c,
  * region contains zeroes, and BDRV_BLOCK_DATA otherwise.
  */
 static int coroutine_fn GRAPH_RDLOCK
-quorum_co_block_status(BlockDriverState *bs, bool want_zero,
+quorum_co_block_status(BlockDriverState *bs, unsigned int mode,
                        int64_t offset, int64_t count,
                        int64_t *pnum, int64_t *map, BlockDriverState **file)
 {
@@ -1238,7 +1238,7 @@ quorum_co_block_status(BlockDriverState *bs, bool want_zero,
     for (i = 0; i < s->num_children; i++) {
         int64_t bytes;
         ret = bdrv_co_common_block_status_above(s->children[i]->bs, NULL, false,
-                                                want_zero, offset, count,
+                                                mode, offset, count,
                                                 &bytes, NULL, NULL, NULL);
         if (ret < 0) {
             quorum_report_bad(QUORUM_OP_TYPE_READ, offset, count,

diff --git a/block/raw-format.c b/block/raw-format.c
index e08526e2ecad515a3eb4b21985a531cb9ac865fa..df16ac1ea25111df9a603cd5a765f9b6f201211f 100644 (file)
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -283,8 +283,8 @@ fail:
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-raw_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
-                    int64_t bytes, int64_t *pnum, int64_t *map,
+raw_co_block_status(BlockDriverState *bs, unsigned int mode,
+                    int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map,
                     BlockDriverState **file)
 {
     BDRVRawState *s = bs->opaque;

diff --git a/block/rbd.c b/block/rbd.c
index 7446e66659ee2ec330b66d270a109766ee1613f9..951cd63f9aedf2d0b82b84940d5913570618e18b 100644 (file)
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1503,9 +1503,9 @@ static int qemu_rbd_diff_iterate_cb(uint64_t offs, size_t len,
 }
 
 static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
-                                                 bool want_zero, int64_t offset,
-                                                 int64_t bytes, int64_t *pnum,
-                                                 int64_t *map,
+                                                 unsigned int mode,
+                                                 int64_t offset, int64_t bytes,
+                                                 int64_t *pnum, int64_t *map,
                                                  BlockDriverState **file)
 {
     BDRVRBDState *s = bs->opaque;

diff --git a/block/snapshot-access.c b/block/snapshot-access.c
index 71ac83c01f09e1022258565458cc15d95780a16c..17ed2402db8148a931b3282c6ce81d5569f1d315 100644 (file)
--- a/block/snapshot-access.c
+++ b/block/snapshot-access.c
@@ -41,11 +41,11 @@ snapshot_access_co_preadv_part(BlockDriverState *bs,
 
 static int coroutine_fn GRAPH_RDLOCK
 snapshot_access_co_block_status(BlockDriverState *bs,
-                                bool want_zero, int64_t offset,
+                                unsigned int mode, int64_t offset,
                                 int64_t bytes, int64_t *pnum,
                                 int64_t *map, BlockDriverState **file)
 {
-    return bdrv_co_snapshot_block_status(bs->file->bs, want_zero, offset,
+    return bdrv_co_snapshot_block_status(bs->file->bs, mode, offset,
                                          bytes, pnum, map, file);
 }
 

diff --git a/block/vdi.c b/block/vdi.c
index a2da6ecab01c2af8ff06a9f8b1b6c2c193a4527f..3ddc62a5690d861b6e9ad05199865e2535916085 100644 (file)
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -523,8 +523,8 @@ static int vdi_reopen_prepare(BDRVReopenState *state,
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-vdi_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
-                    int64_t bytes, int64_t *pnum, int64_t *map,
+vdi_co_block_status(BlockDriverState *bs, unsigned int mode,
+                    int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map,
                     BlockDriverState **file)
 {
     BDRVVdiState *s = (BDRVVdiState *)bs->opaque;

diff --git a/block/vmdk.c b/block/vmdk.c
index 2adec499122c8578268885e4c162451d2216172e..9c7ab037e14c2d0b262f0bc05dfff12f4e6fe986 100644 (file)
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1777,7 +1777,7 @@ static inline uint64_t vmdk_find_offset_in_cluster(VmdkExtent *extent,
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-vmdk_co_block_status(BlockDriverState *bs, bool want_zero,
+vmdk_co_block_status(BlockDriverState *bs, unsigned int mode,
                      int64_t offset, int64_t bytes, int64_t *pnum,
                      int64_t *map, BlockDriverState **file)
 {

diff --git a/block/vpc.c b/block/vpc.c
index 0309e319f606bde5e4d475f1bca957e6cf8083a6..801ff5793f8757649d943c7942b4074fa3b11305 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -726,7 +726,7 @@ fail:
 }
 
 static int coroutine_fn GRAPH_RDLOCK
-vpc_co_block_status(BlockDriverState *bs, bool want_zero,
+vpc_co_block_status(BlockDriverState *bs, unsigned int mode,
                     int64_t offset, int64_t bytes,
                     int64_t *pnum, int64_t *map,
                     BlockDriverState **file)

diff --git a/block/vvfat.c b/block/vvfat.c
index 91d69b3cc83e2575f056363c3fc69a338bcade78..814796d9185f14183194e0421b8c3ef052c81543 100644 (file)
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3134,9 +3134,9 @@ vvfat_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
 }
 
 static int coroutine_fn vvfat_co_block_status(BlockDriverState *bs,
-                                              bool want_zero, int64_t offset,
-                                              int64_t bytes, int64_t *n,
-                                              int64_t *map,
+                                              unsigned int mode,
+                                              int64_t offset, int64_t bytes,
+                                              int64_t *n, int64_t *map,
                                               BlockDriverState **file)
 {
     *n = bytes;

diff --git a/include/block/block-common.h b/include/block/block-common.h
index 0b831ef87b1bd87d795cac3110b2aae1f08bc69e..c8c626daeaa593d03019378e8d1476775228586d 100644 (file)
--- a/include/block/block-common.h
+++ b/include/block/block-common.h
@@ -333,6 +333,17 @@ typedef enum {
 #define BDRV_BLOCK_RECURSE      0x40
 #define BDRV_BLOCK_COMPRESSED   0x80
 
+/*
+ * Block status hints: the bitwise-or of these flags emphasize what
+ * the caller hopes to learn, and some drivers may be able to give
+ * faster answers by doing less work when the hint permits.
+ */
+#define BDRV_WANT_ZERO          BDRV_BLOCK_ZERO
+#define BDRV_WANT_OFFSET_VALID  BDRV_BLOCK_OFFSET_VALID
+#define BDRV_WANT_ALLOCATED     BDRV_BLOCK_ALLOCATED
+#define BDRV_WANT_PRECISE       (BDRV_WANT_ZERO | BDRV_WANT_OFFSET_VALID | \
+                                 BDRV_WANT_OFFSET_VALID)
+
 typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 
 typedef struct BDRVReopenState {

diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 0d8187f6567e5d87fbec323a8810aa548b390d2f..2982dd31180cfa412c5d7ec39c3ae3e294ea1b05 100644 (file)
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -604,15 +604,16 @@ struct BlockDriver {
      * according to the current layer, and should only need to set
      * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
      * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
-     * layer, the result should be 0 (and not BDRV_BLOCK_ZERO).  See
-     * block.h for the overall meaning of the bits.  As a hint, the
-     * flag want_zero is true if the caller cares more about precise
-     * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
-     * overall allocation (favor larger *pnum, perhaps by reporting
-     * _DATA instead of _ZERO).  The block layer guarantees input
-     * clamped to bdrv_getlength() and aligned to request_alignment,
-     * as well as non-NULL pnum, map, and file; in turn, the driver
-     * must return an error or set pnum to an aligned non-zero value.
+     * layer, the result should be 0 (and not BDRV_BLOCK_ZERO).  The
+     * caller will synthesize BDRV_BLOCK_ALLOCATED based on the
+     * non-zero results.  See block.h for the overall meaning of the
+     * bits.  As a hint, the flags in @mode may include a bitwise-or
+     * of BDRV_WANT_ALLOCATED, BDRV_WANT_OFFSET_VALID, or
+     * BDRV_WANT_ZERO based on what the caller is looking for in the
+     * results.  The block layer guarantees input clamped to
+     * bdrv_getlength() and aligned to request_alignment, as well as
+     * non-NULL pnum, map, and file; in turn, the driver must return
+     * an error or set pnum to an aligned non-zero value.
      *
      * Note that @bytes is just a hint on how big of a region the
      * caller wants to inspect.  It is not a limit on *pnum.
@@ -624,8 +625,8 @@ struct BlockDriver {
      * to clamping *pnum for return to its caller.
      */
     int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_block_status)(
-        BlockDriverState *bs,
-        bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
+        BlockDriverState *bs, unsigned int mode,
+        int64_t offset, int64_t bytes, int64_t *pnum,
         int64_t *map, BlockDriverState **file);
 
     /*
@@ -649,8 +650,8 @@ struct BlockDriver {
         QEMUIOVector *qiov, size_t qiov_offset);
 
     int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_snapshot_block_status)(
-        BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes,
-        int64_t *pnum, int64_t *map, BlockDriverState **file);
+        BlockDriverState *bs, unsigned int mode, int64_t offset,
+        int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file);
 
     int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_pdiscard_snapshot)(
         BlockDriverState *bs, int64_t offset, int64_t bytes);

diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h
index 4a7cf2b4fdc02b761d6a270a6cd4b3bb759aaf9b..4f94eb3c5a20d2fa386e2031f0edbdf6b0d946f2 100644 (file)
--- a/include/block/block_int-io.h
+++ b/include/block/block_int-io.h
@@ -38,8 +38,8 @@
 int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv_snapshot(BdrvChild *child,
     int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset);
 int coroutine_fn GRAPH_RDLOCK bdrv_co_snapshot_block_status(
-    BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes,
-    int64_t *pnum, int64_t *map, BlockDriverState **file);
+    BlockDriverState *bs, unsigned int mode, int64_t offset,
+    int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file);
 int coroutine_fn GRAPH_RDLOCK bdrv_co_pdiscard_snapshot(BlockDriverState *bs,
     int64_t offset, int64_t bytes);
 

diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index 2b358eaaa820f582c5c384beddd1c2844d8dce11..e26b3be593985e1354b98654279ae24b98d5f043 100644 (file)
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -63,7 +63,7 @@ bdrv_test_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
 }
 
 static int coroutine_fn bdrv_test_co_block_status(BlockDriverState *bs,
-                                                  bool want_zero,
+                                                  unsigned int mode,
                                                   int64_t offset, int64_t count,
                                                   int64_t *pnum, int64_t *map,
                                                   BlockDriverState **file)