block: Use bdrv_refresh_filename() to pull

Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards).  However, that is
nonviable, considering that we want child changes not to concern
parents.

Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.

This patch is an intermediate step.  It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used.  The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.

Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.

In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/block.c b/block.c
index 16d59e0b32eb26ac817493d65eda83bad83a5fee..88aa687a6808ac3f1caa036e6feef112556cf1ae 100644 (file)
--- a/block.c
+++ b/block.c
@@ -323,8 +323,11 @@ void bdrv_get_full_backing_filename_from_filename(const char *backed,
 void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
                                     Error **errp)
 {
-    char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
+    char *backed;
 
+    bdrv_refresh_filename(bs);
+
+    backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
     bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
                                                  dest, sz, errp);
 }
@@ -1004,6 +1007,8 @@ static void bdrv_backing_attach(BdrvChild *c)
                "node is used as backing hd of '%s'",
                bdrv_get_device_or_node_name(parent));
 
+    bdrv_refresh_filename(backing_hd);
+
     parent->open_flags &= ~BDRV_O_NO_BACKING;
     pstrcpy(parent->backing_file, sizeof(parent->backing_file),
             backing_hd->filename);
@@ -1413,6 +1418,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
     }
 
     if (file != NULL) {
+        bdrv_refresh_filename(blk_bs(file));
         filename = blk_bs(file)->filename;
     } else {
         /*
@@ -2334,8 +2340,6 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
         bdrv_unref(backing_hd);
     }
 
-    bdrv_refresh_filename(bs);
-
 out:
     bdrv_refresh_limits(bs, NULL);
 }
@@ -2864,8 +2868,6 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
         g_free(child_key_dot);
     }
 
-    bdrv_refresh_filename(bs);
-
     /* Check if any unknown options were used */
     if (qdict_size(options) != 0) {
         const QDictEntry *entry = qdict_first(options);
@@ -3310,6 +3312,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
             if (local_err != NULL) {
                 error_propagate(errp, local_err);
             } else {
+                bdrv_refresh_filename(reopen_state->bs);
                 error_setg(errp, "failed while preparing to reopen image '%s'",
                            reopen_state->bs->filename);
             }
@@ -3937,7 +3940,10 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
     /* success - we can delete the intermediate states, and link top->base */
     /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
      * we've figured out how they should work. */
-    backing_file_str = backing_file_str ? backing_file_str : base->filename;
+    if (!backing_file_str) {
+        bdrv_refresh_filename(base);
+        backing_file_str = base->filename;
+    }
 
     QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
         /* Check whether we are allowed to switch c from top to base */
@@ -4485,16 +4491,6 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
     return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
 }
 
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
-{
-    if (bs->backing && bs->backing->bs->encrypted)
-        return bs->backing_file;
-    else if (bs->encrypted)
-        return bs->filename;
-    else
-        return NULL;
-}
-
 void bdrv_get_backing_filename(BlockDriverState *bs,
                                char *filename, int filename_size)
 {
@@ -4615,6 +4611,9 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 
     is_protocol = path_has_protocol(backing_file);
 
+    /* This will recursively refresh everything in the backing chain */
+    bdrv_refresh_filename(bs);
+
     for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
 
         /* If either of the filename paths is actually a protocol, then

diff --git a/block/qapi.c b/block/qapi.c
index 00291f910591d988337e282126f1812f026d5ad8..4623de1d7bc93263d33dc63198fbef8dfd147627 100644 (file)
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -51,6 +51,8 @@ BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
         return NULL;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_malloc0(sizeof(*info));
     info->file                   = g_strdup(bs->filename);
     info->ro                     = bs->read_only;
@@ -264,6 +266,8 @@ void bdrv_query_image_info(BlockDriverState *bs,
         goto out;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_new0(ImageInfo, 1);
     info->filename        = g_strdup(bs->filename);
     info->format          = g_strdup(bdrv_get_format_name(bs));

diff --git a/block/raw-format.c b/block/raw-format.c
index 6f6dc99b2ceb74540ce7f1064e082ee889c5670d..d07bcdae62d7cd02ac70a96bba210e828c113fb4 100644 (file)
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -436,6 +436,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
             bs->file->bs->supported_zero_flags);
 
     if (bs->probed && !bdrv_is_read_only(bs)) {
+        bdrv_refresh_filename(bs->file->bs);
         fprintf(stderr,
                 "WARNING: Image format was not specified for '%s' and probing "
                 "guessed raw.\n"

diff --git a/block/replication.c b/block/replication.c
index e70dd950015ec9e0df71a2cd5d90b59c9f372bd4..9b332002ee388fb90ea5251615c7949f35301236 100644 (file)
--- a/block/replication.c
+++ b/block/replication.c
@@ -616,8 +616,6 @@ static void replication_done(void *opaque, int ret)
     if (ret == 0) {
         s->stage = BLOCK_REPLICATION_DONE;
 
-        /* refresh top bs's filename */
-        bdrv_refresh_filename(bs);
         s->active_disk = NULL;
         s->secondary_disk = NULL;
         s->hidden_disk = NULL;

diff --git a/block/vhdx-log.c b/block/vhdx-log.c
index ecd64266c5ef167f9b07ec42613f46a8918f014f..3149ff08d803d8a358606b941096ad2608ec355d 100644 (file)
--- a/block/vhdx-log.c
+++ b/block/vhdx-log.c
@@ -803,6 +803,7 @@ int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,
 
     if (logs.valid) {
         if (bs->read_only) {
+            bdrv_refresh_filename(bs);
             ret = -EPERM;
             error_setg(errp,
                        "VHDX image file '%s' opened read-only, but "

diff --git a/block/vmdk.c b/block/vmdk.c
index 096e8eb662745221473a090834bdbabfb536f8d9..117dc6adfe341427348053f17a05647300d871de 100644 (file)
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -479,6 +479,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                      extent->l1_table,
                      l1_size);
     if (ret < 0) {
+        bdrv_refresh_filename(extent->file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read l1 table from extent '%s'",
                          extent->file->bs->filename);
@@ -499,6 +500,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                          extent->l1_backup_table,
                          l1_size);
         if (ret < 0) {
+            bdrv_refresh_filename(extent->file->bs);
             error_setg_errno(errp, -ret,
                              "Could not read l1 backup table from extent '%s'",
                              extent->file->bs->filename);
@@ -530,6 +532,7 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -607,6 +610,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -861,6 +865,7 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
         if (!path_is_absolute(fname) && !path_has_protocol(fname) &&
             !desc_file_path[0])
         {
+            bdrv_refresh_filename(bs->file->bs);
             error_setg(errp, "Cannot use relative extent paths with VMDK "
                        "descriptor file '%s'", bs->file->bs->filename);
             return -EINVAL;
@@ -2470,6 +2475,7 @@ static ImageInfo *vmdk_get_extent_info(VmdkExtent *extent)
 {
     ImageInfo *info = g_new0(ImageInfo, 1);
 
+    bdrv_refresh_filename(extent->file->bs);
     *info = (ImageInfo){
         .filename         = g_strdup(extent->file->bs->filename),
         .format           = g_strdup(extent->type),

diff --git a/blockdev.c b/blockdev.c
index 8714ad2702f9eb0b08cbf61fd167021d9ec2a1bc..7e6bf9955c8cab8bb5204c7990217074f5ef98c9 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -1627,6 +1627,7 @@ static void external_snapshot_prepare(BlkActionState *common,
                 error_setg_errno(errp, -size, "bdrv_getlength failed");
                 goto out;
             }
+            bdrv_refresh_filename(state->old_bs);
             bdrv_img_create(new_image_file, format,
                             state->old_bs->filename,
                             state->old_bs->drv->format_name,
@@ -3230,6 +3231,7 @@ void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
             goto out;
         }
         assert(bdrv_get_aio_context(base_bs) == aio_context);
+        bdrv_refresh_filename(base_bs);
         base_name = base_bs->filename;
     }
 
@@ -3349,6 +3351,10 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
             goto out;
         }
     } else if (has_top && top) {
+        /* This strcmp() is just a shortcut, there is no need to
+         * refresh @bs's filename.  If it mismatches,
+         * bdrv_find_backing_image() will do the refresh and may still
+         * return @bs. */
         if (strcmp(bs->filename, top) != 0) {
             top_bs = bdrv_find_backing_image(bs, top);
         }
@@ -3509,6 +3515,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
         assert(backup->format);
         if (source) {
+            bdrv_refresh_filename(source);
             bdrv_img_create(backup->target, backup->format, source->filename,
                             source->drv->format_name, NULL,
                             size, flags, false, &local_err);
@@ -3889,6 +3896,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
             break;
         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
             /* create new image with backing file */
+            bdrv_refresh_filename(source);
             bdrv_img_create(arg->target, format,
                             source->filename,
                             source->drv->format_name,

diff --git a/include/block/block.h b/include/block/block.h
index 73357c6c2501f64f2c8851f03805b037265825ed..aaae9009256e45d4ab925f41f1816beed92fcf43 100644 (file)
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -485,7 +485,6 @@ void bdrv_round_to_clusters(BlockDriverState *bs,
                             int64_t *cluster_offset,
                             int64_t *cluster_bytes);
 
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 void bdrv_get_backing_filename(BlockDriverState *bs,
                                char *filename, int filename_size);
 void bdrv_get_full_backing_filename(BlockDriverState *bs,

diff --git a/qemu-img.c b/qemu-img.c
index eb5045c742d1caf27ae08b49a3631d2c17288a92..d2fc28c987f064c32b07e30d9a6244d6ab87f014 100644 (file)
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2790,6 +2790,7 @@ static int get_block_status(BlockDriverState *bs, int64_t offset,
     BlockDriverState *file;
     bool has_offset;
     int64_t map;
+    char *filename = NULL;
 
     /* As an optimization, we could cache the current range of unallocated
      * clusters in each file of the chain, and avoid querying the same
@@ -2817,6 +2818,11 @@ static int get_block_status(BlockDriverState *bs, int64_t offset,
 
     has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID);
 
+    if (file && has_offset) {
+        bdrv_refresh_filename(file);
+        filename = file->filename;
+    }
+
     *e = (MapEntry) {
         .start = offset,
         .length = bytes,
@@ -2825,8 +2831,8 @@ static int get_block_status(BlockDriverState *bs, int64_t offset,
         .offset = map,
         .has_offset = has_offset,
         .depth = depth,
-        .has_filename = file && has_offset,
-        .filename = file && has_offset ? file->filename : NULL,
+        .has_filename = filename,
+        .filename = filename,
     };
 
     return 0;
@@ -3334,6 +3340,7 @@ static int img_rebase(int argc, char **argv)
                 qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true);
             }
 
+            bdrv_refresh_filename(bs);
             overlay_filename = bs->exact_filename[0] ? bs->exact_filename
                                                      : bs->filename;
             out_real_path = g_malloc(PATH_MAX);