Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- file-posix: Mitigate file fragmentation with extent size hints
- Tighten qemu-img rules on missing backing format
- qemu-img map: Don't limit block status request size
- Fix crash with virtio-scsi and iothreads

# gpg: Signature made Tue 14 Jul 2020 14:24:19 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: Avoid stale pointer dereference in blk_get_aio_context()
  qemu-img: Deprecate use of -b without -F
  block: Add support to warn on backing file change without format
  iotests: Specify explicit backing format where sensible
  qcow2: Deprecate use of qemu-img amend to change backing file
  block: Error if backing file fails during creation without -u
  qcow: Tolerate backing_fmt=
  vmdk: Add trivial backing_fmt support
  sheepdog: Add trivial backing_fmt support
  block: Finish deprecation of 'qemu-img convert -n -o'
  qemu-img: Flush stdout before before potential stderr messages
  file-posix: Mitigate file fragmentation with extent size hints
  iotests/059: Filter out disk size with more standard filter
  qemu-img map: Don't limit block status request size
  iotests: Simplify _filter_img_create() a bit

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

7 files changed, 103 insertions, 6 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index 6936b25c83..0bf0188133 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -808,6 +808,7 @@ void blk_remove_bs(BlockBackend *blk)
 {
     ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
     BlockDriverState *bs;
+    BdrvChild *root;
 
     notifier_list_notify(&blk->remove_bs_notifiers, blk);
     if (tgm->throttle_state) {
@@ -825,8 +826,9 @@ void blk_remove_bs(BlockBackend *blk)
      * to avoid that and a potential QEMU crash.
      */
     blk_drain(blk);
-    bdrv_root_unref_child(blk->root);
+    root = blk->root;
     blk->root = NULL;
+    bdrv_root_unref_child(root);
 }
 
 /*
diff --git a/block/file-posix.c b/block/file-posix.c
index 1989eae85f..8067e238cb 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -30,6 +30,7 @@
 #include "block/block_int.h"
 #include "qemu/module.h"
 #include "qemu/option.h"
+#include "qemu/units.h"
 #include "trace.h"
 #include "block/thread-pool.h"
 #include "qemu/iov.h"
@@ -2318,6 +2319,14 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
     if (!file_opts->has_preallocation) {
         file_opts->preallocation = PREALLOC_MODE_OFF;
     }
+    if (!file_opts->has_extent_size_hint) {
+        file_opts->extent_size_hint = 1 * MiB;
+    }
+    if (file_opts->extent_size_hint > UINT32_MAX) {
+        result = -EINVAL;
+        error_setg(errp, "Extent size hint is too large");
+        goto out;
+    }
 
     /* Create file */
     fd = qemu_open(file_opts->filename, O_RDWR | O_CREAT | O_BINARY, 0644);
@@ -2375,6 +2384,27 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
         }
 #endif
     }
+#ifdef FS_IOC_FSSETXATTR
+    /*
+     * Try to set the extent size hint. Failure is not fatal, and a warning is
+     * only printed if the option was explicitly specified.
+     */
+    {
+        struct fsxattr attr;
+        result = ioctl(fd, FS_IOC_FSGETXATTR, &attr);
+        if (result == 0) {
+            attr.fsx_xflags |= FS_XFLAG_EXTSIZE;
+            attr.fsx_extsize = file_opts->extent_size_hint;
+            result = ioctl(fd, FS_IOC_FSSETXATTR, &attr);
+        }
+        if (result < 0 && file_opts->has_extent_size_hint &&
+            file_opts->extent_size_hint)
+        {
+            warn_report("Failed to set extent size hint: %s",
+                        strerror(errno));
+        }
+    }
+#endif
 
     /* Resize and potentially preallocate the file to the desired
      * final size */
@@ -2410,6 +2440,8 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
 {
     BlockdevCreateOptions options;
     int64_t total_size = 0;
+    int64_t extent_size_hint = 0;
+    bool has_extent_size_hint = false;
     bool nocow = false;
     PreallocMode prealloc;
     char *buf = NULL;
@@ -2421,6 +2453,11 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
     /* Read out options */
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                           BDRV_SECTOR_SIZE);
+    if (qemu_opt_get(opts, BLOCK_OPT_EXTENT_SIZE_HINT)) {
+        has_extent_size_hint = true;
+        extent_size_hint =
+            qemu_opt_get_size_del(opts, BLOCK_OPT_EXTENT_SIZE_HINT, -1);
+    }
     nocow = qemu_opt_get_bool(opts, BLOCK_OPT_NOCOW, false);
     buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
     prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
@@ -2440,6 +2477,8 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
             .preallocation      = prealloc,
             .has_nocow          = true,
             .nocow              = nocow,
+            .has_extent_size_hint = has_extent_size_hint,
+            .extent_size_hint   = extent_size_hint,
         },
     };
     return raw_co_create(&options, errp);
@@ -2930,6 +2969,11 @@ static QemuOptsList raw_create_opts = {
 #endif
                     ", full)"
         },
+        {
+            .name = BLOCK_OPT_EXTENT_SIZE_HINT,
+            .type = QEMU_OPT_SIZE,
+            .help = "Extent size hint for the image file, 0 to disable"
+        },
         { /* end of list */ }
     }
 };
diff --git a/block/qcow.c b/block/qcow.c
index 1e134f3445..e514a86fe5 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -938,10 +938,11 @@ static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
 {
     BlockdevCreateOptions *create_options = NULL;
     BlockDriverState *bs = NULL;
-    QDict *qdict;
+    QDict *qdict = NULL;
     Visitor *v;
     const char *val;
     int ret;
+    char *backing_fmt;
 
     static const QDictRenames opt_renames[] = {
         { BLOCK_OPT_BACKING_FILE,       "backing-file" },
@@ -949,6 +950,17 @@ static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
         { NULL, NULL },
     };
 
+    /*
+     * We can't actually store a backing format, but can check that
+     * the user's request made sense.
+     */
+    backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
+    if (backing_fmt && !bdrv_find_format(backing_fmt)) {
+        error_setg(errp, "unrecognized backing format '%s'", backing_fmt);
+        ret = -EINVAL;
+        goto fail;
+    }
+
     /* Parse options and convert legacy syntax */
     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
 
@@ -1012,6 +1024,7 @@ static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
 
     ret = 0;
 fail:
+    g_free(backing_fmt);
     qobject_unref(qdict);
     bdrv_unref(bs);
     qapi_free_BlockdevCreateOptions(create_options);
@@ -1147,6 +1160,11 @@ static QemuOptsList qcow_create_opts = {
             .help = "File name of a base image"
         },
         {
+            .name = BLOCK_OPT_BACKING_FMT,
+            .type = QEMU_OPT_STRING,
+            .help = "Format of the backing image",
+        },
+        {
             .name = BLOCK_OPT_ENCRYPT,
             .type = QEMU_OPT_BOOL,
             .help = "Encrypt the image with format 'aes'. (Deprecated "
diff --git a/block/qcow2.c b/block/qcow2.c
index ea33673c55..fadf3422f8 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3627,7 +3627,7 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
         }
 
         ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
-                                       backing_format);
+                                       backing_format, false);
         if (ret < 0) {
             error_setg_errno(errp, -ret, "Could not assign backing file '%s' "
                              "with format '%s'", qcow2_opts->backing_file,
@@ -5511,6 +5511,11 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
     }
 
     if (backing_file || backing_format) {
+        if (g_strcmp0(backing_file, s->image_backing_file) ||
+            g_strcmp0(backing_format, s->image_backing_format)) {
+            warn_report("Deprecated use of amend to alter the backing file; "
+                        "use qemu-img rebase instead");
+        }
         ret = qcow2_change_backing_file(bs,
                     backing_file ?: s->image_backing_file,
                     backing_format ?: s->image_backing_format);
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 6c487c8322..cbbebc1aaf 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2151,13 +2151,21 @@ static int coroutine_fn sd_co_create_opts(BlockDriver *drv,
                                           Error **errp)
 {
     BlockdevCreateOptions *create_options = NULL;
-    QDict *qdict, *location_qdict;
+    QDict *qdict = NULL, *location_qdict;
     Visitor *v;
-    char *redundancy;
+    char *redundancy = NULL;
     Error *local_err = NULL;
     int ret;
+    char *backing_fmt = NULL;
 
     redundancy = qemu_opt_get_del(opts, BLOCK_OPT_REDUNDANCY);
+    backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
+
+    if (backing_fmt && strcmp(backing_fmt, "sheepdog") != 0) {
+        error_setg(errp, "backing_file must be a sheepdog image");
+        ret = -EINVAL;
+        goto fail;
+    }
 
     qdict = qemu_opts_to_qdict(opts, NULL);
     qdict_put_str(qdict, "driver", "sheepdog");
@@ -2220,6 +2228,7 @@ fail:
     qapi_free_BlockdevCreateOptions(create_options);
     qobject_unref(qdict);
     g_free(redundancy);
+    g_free(backing_fmt);
     return ret;
 }
 
@@ -3178,6 +3187,11 @@ static QemuOptsList sd_create_opts = {
             .help = "File name of a base image"
         },
         {
+            .name = BLOCK_OPT_BACKING_FMT,
+            .type = QEMU_OPT_STRING,
+            .help = "Must be 'sheepdog' if present",
+        },
+        {
             .name = BLOCK_OPT_PREALLOC,
             .type = QEMU_OPT_STRING,
             .help = "Preallocation mode (allowed values: off, full)"
diff --git a/block/stream.c b/block/stream.c
index aa2e7af98e..310ccbaa4c 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -78,7 +78,7 @@ static int stream_prepare(Job *job)
             }
         }
         bdrv_set_backing_hd(bs, base, &local_err);
-        ret = bdrv_change_backing_file(bs, base_id, base_fmt);
+        ret = bdrv_change_backing_file(bs, base_id, base_fmt, false);
         if (local_err) {
             error_report_err(local_err);
             return -EPERM;
diff --git a/block/vmdk.c b/block/vmdk.c
index 28cec50f38..bf9df5ce92 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2633,6 +2633,14 @@ static int coroutine_fn vmdk_co_create_opts(BlockDriver *drv,
     bool zeroed_grain;
     bool compat6;
     VMDKCreateOptsData data;
+    char *backing_fmt = NULL;
+
+    backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
+    if (backing_fmt && strcmp(backing_fmt, "vmdk") != 0) {
+        error_setg(errp, "backing_file must be a vmdk image");
+        ret = -EINVAL;
+        goto exit;
+    }
 
     if (filename_decompose(filename, path, prefix, postfix, PATH_MAX, errp)) {
         ret = -EINVAL;
@@ -2691,6 +2699,7 @@ static int coroutine_fn vmdk_co_create_opts(BlockDriver *drv,
                             vmdk_co_create_opts_cb, &data, errp);
 
 exit:
+    g_free(backing_fmt);
     g_free(adapter_type);
     g_free(backing_file);
     g_free(hw_version);
@@ -3027,6 +3036,11 @@ static QemuOptsList vmdk_create_opts = {
             .help = "File name of a base image"
         },
         {
+            .name = BLOCK_OPT_BACKING_FMT,
+            .type = QEMU_OPT_STRING,
+            .help = "Must be 'vmdk' if present",
+        },
+        {
             .name = BLOCK_OPT_COMPAT6,
             .type = QEMU_OPT_BOOL,
             .help = "VMDK version 6 image",