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Block layer fixes for 2.9.0-rc0

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

Block layer fixes for 2.9.0-rc0

# gpg: Signature made Tue 07 Mar 2017 14:59:18 GMT
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (27 commits)
  commit: Don't use error_abort in commit_start
  block: Don't use error_abort in blk_new_open
  sheepdog: Support blockdev-add
  qapi-schema: Rename SocketAddressFlat's variant tcp to inet
  qapi-schema: Rename GlusterServer to SocketAddressFlat
  gluster: Plug memory leaks in qemu_gluster_parse_json()
  gluster: Don't duplicate qapi-util.c's qapi_enum_parse()
  gluster: Drop assumptions on SocketTransport names
  sheepdog: Implement bdrv_parse_filename()
  sheepdog: Use SocketAddress and socket_connect()
  sheepdog: Report errors in pseudo-filename more usefully
  sheepdog: Don't truncate long VDI name in _open(), _create()
  sheepdog: Fix snapshot ID parsing in _open(), _create, _goto()
  sheepdog: Mark sd_snapshot_delete() lossage FIXME
  sheepdog: Fix error handling sd_create()
  sheepdog: Fix error handling in sd_snapshot_delete()
  sheepdog: Defuse time bomb in sd_open() error handling
  block: Fix error handling in bdrv_replace_in_backing_chain()
  block: Handle permission errors in change_parent_backing_link()
  block: Ignore multiple children in bdrv_check_update_perm()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2017-03-08 09:47:52 +00:00
commit b64842dee4
11 changed files with 626 additions and 329 deletions
Download patch file Download diff file Expand all files Collapse all files

184
block.c
View file

@ -1403,7 +1403,8 @@ static int bdrv_fill_options(QDict **options, const char *filename,
* or bdrv_abort_perm_update().
*/
static int bdrv_check_perm(BlockDriverState *bs, uint64_t cumulative_perms,
uint64_t cumulative_shared_perms, Error **errp)
uint64_t cumulative_shared_perms,
GSList *ignore_children, Error **errp)
{
BlockDriver *drv = bs->drv;
BdrvChild *c;
@ -1439,7 +1440,8 @@ static int bdrv_check_perm(BlockDriverState *bs, uint64_t cumulative_perms,
drv->bdrv_child_perm(bs, c, c->role,
cumulative_perms, cumulative_shared_perms,
&cur_perm, &cur_shared);
ret = bdrv_child_check_perm(c, cur_perm, cur_shared, errp);
ret = bdrv_child_check_perm(c, cur_perm, cur_shared, ignore_children,
errp);
if (ret < 0) {
return ret;
}
@ -1559,15 +1561,15 @@ static char *bdrv_perm_names(uint64_t perm)
/*
* Checks whether a new reference to @bs can be added if the new user requires
* @new_used_perm/@new_shared_perm as its permissions. If @ignore_child is set,
* this old reference is ignored in the calculations; this allows checking
* permission updates for an existing reference.
* @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
* set, the BdrvChild objects in this list are ignored in the calculations;
* this allows checking permission updates for an existing reference.
*
* Needs to be followed by a call to either bdrv_set_perm() or
* bdrv_abort_perm_update(). */
static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm,
uint64_t new_shared_perm,
BdrvChild *ignore_child, Error **errp)
GSList *ignore_children, Error **errp)
{
BdrvChild *c;
uint64_t cumulative_perms = new_used_perm;
@ -1577,7 +1579,7 @@ static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm,
assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED);
QLIST_FOREACH(c, &bs->parents, next_parent) {
if (c == ignore_child) {
if (g_slist_find(ignore_children, c)) {
continue;
}
@ -1607,15 +1609,22 @@ static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm,
cumulative_shared_perms &= c->shared_perm;
}
return bdrv_check_perm(bs, cumulative_perms, cumulative_shared_perms, errp);
return bdrv_check_perm(bs, cumulative_perms, cumulative_shared_perms,
ignore_children, errp);
}
/* Needs to be followed by a call to either bdrv_child_set_perm() or
* bdrv_child_abort_perm_update(). */
int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
Error **errp)
GSList *ignore_children, Error **errp)
{
return bdrv_check_update_perm(c->bs, perm, shared, c, errp);
int ret;
ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c);
ret = bdrv_check_update_perm(c->bs, perm, shared, ignore_children, errp);
g_slist_free(ignore_children);
return ret;
}
void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
@ -1640,7 +1649,7 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
{
int ret;
ret = bdrv_child_check_perm(c, perm, shared, errp);
ret = bdrv_child_check_perm(c, perm, shared, NULL, errp);
if (ret < 0) {
bdrv_child_abort_perm_update(c);
return ret;
@ -1718,11 +1727,10 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
*nshared = shared;
}
static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
bool check_new_perm)
static void bdrv_replace_child_noperm(BdrvChild *child,
BlockDriverState *new_bs)
{
BlockDriverState *old_bs = child->bs;
uint64_t perm, shared_perm;
if (old_bs) {
if (old_bs->quiesce_counter && child->role->drained_end) {
@ -1732,13 +1740,6 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
child->role->detach(child);
}
QLIST_REMOVE(child, next_parent);
/* Update permissions for old node. This is guaranteed to succeed
* because we're just taking a parent away, so we're loosening
* restrictions. */
bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
bdrv_check_perm(old_bs, perm, shared_perm, &error_abort);
bdrv_set_perm(old_bs, perm, shared_perm);
}
child->bs = new_bs;
@ -1749,18 +1750,38 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
child->role->drained_begin(child);
}
bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
if (check_new_perm) {
bdrv_check_perm(new_bs, perm, shared_perm, &error_abort);
}
bdrv_set_perm(new_bs, perm, shared_perm);
if (child->role->attach) {
child->role->attach(child);
}
}
}
static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
bool check_new_perm)
{
BlockDriverState *old_bs = child->bs;
uint64_t perm, shared_perm;
if (old_bs) {
/* Update permissions for old node. This is guaranteed to succeed
* because we're just taking a parent away, so we're loosening
* restrictions. */
bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
bdrv_check_perm(old_bs, perm, shared_perm, NULL, &error_abort);
bdrv_set_perm(old_bs, perm, shared_perm);
}
bdrv_replace_child_noperm(child, new_bs);
if (new_bs) {
bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
if (check_new_perm) {
bdrv_check_perm(new_bs, perm, shared_perm, NULL, &error_abort);
}
bdrv_set_perm(new_bs, perm, shared_perm);
}
}
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
const char *child_name,
const BdrvChildRole *child_role,
@ -2891,35 +2912,82 @@ void bdrv_close_all(void)
assert(QTAILQ_EMPTY(&all_bdrv_states));
}
static void change_parent_backing_link(BlockDriverState *from,
BlockDriverState *to)
static bool should_update_child(BdrvChild *c, BlockDriverState *to)
{
BdrvChild *c, *next, *to_c;
BdrvChild *to_c;
if (c->role->stay_at_node) {
return false;
}
if (c->role == &child_backing) {
/* If @from is a backing file of @to, ignore the child to avoid
* creating a loop. We only want to change the pointer of other
* parents. */
QLIST_FOREACH(to_c, &to->children, next) {
if (to_c == c) {
break;
}
}
if (to_c) {
return false;
}
}
return true;
}
void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
Error **errp)
{
BdrvChild *c, *next;
GSList *list = NULL, *p;
uint64_t old_perm, old_shared;
uint64_t perm = 0, shared = BLK_PERM_ALL;
int ret;
assert(!atomic_read(&from->in_flight));
assert(!atomic_read(&to->in_flight));
/* Make sure that @from doesn't go away until we have successfully attached
* all of its parents to @to. */
bdrv_ref(from);
/* Put all parents into @list and calculate their cumulative permissions */
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
if (c->role->stay_at_node) {
if (!should_update_child(c, to)) {
continue;
}
if (c->role == &child_backing) {
/* If @from is a backing file of @to, ignore the child to avoid
* creating a loop. We only want to change the pointer of other
* parents. */
QLIST_FOREACH(to_c, &to->children, next) {
if (to_c == c) {
break;
}
}
if (to_c) {
continue;
}
}
list = g_slist_prepend(list, c);
perm |= c->perm;
shared &= c->shared_perm;
}
/* Check whether the required permissions can be granted on @to, ignoring
* all BdrvChild in @list so that they can't block themselves. */
ret = bdrv_check_update_perm(to, perm, shared, list, errp);
if (ret < 0) {
bdrv_abort_perm_update(to);
goto out;
}
/* Now actually perform the change. We performed the permission check for
* all elements of @list at once, so set the permissions all at once at the
* very end. */
for (p = list; p != NULL; p = p->next) {
c = p->data;
bdrv_ref(to);
/* FIXME Are we sure that bdrv_replace_child() can't run into
* &error_abort because of permissions? */
bdrv_replace_child(c, to, true);
bdrv_replace_child_noperm(c, to);
bdrv_unref(from);
}
bdrv_get_cumulative_perm(to, &old_perm, &old_shared);
bdrv_set_perm(to, old_perm | perm, old_shared | shared);
out:
g_slist_free(list);
bdrv_unref(from);
}
/*
@ -2943,16 +3011,18 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
{
Error *local_err = NULL;
assert(!atomic_read(&bs_top->in_flight));
assert(!atomic_read(&bs_new->in_flight));
bdrv_set_backing_hd(bs_new, bs_top, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto out;
}
change_parent_backing_link(bs_top, bs_new);
bdrv_replace_node(bs_top, bs_new, &local_err);
if (local_err) {
error_propagate(errp, local_err);
bdrv_set_backing_hd(bs_new, NULL, &error_abort);
goto out;
}
/* bs_new is now referenced by its new parents, we don't need the
* additional reference any more. */
@ -2960,18 +3030,6 @@ out:
bdrv_unref(bs_new);
}
void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new)
{
assert(!bdrv_requests_pending(old));
assert(!bdrv_requests_pending(new));
bdrv_ref(old);
change_parent_backing_link(old, new);
bdrv_unref(old);
}
static void bdrv_delete(BlockDriverState *bs)
{
assert(!bs->job);