block: Mark bdrv_apply_auto_read_only() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_apply_auto_read_only() need to hold a reader lock for the graph
because it calls bdrv_can_set_read_only(), which indirectly accesses the
parents list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-19-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2023-09-29 16:51:53 +02:00
parent 277f2007ce
commit 018f9dea9c
10 changed files with 22 additions and 5 deletions

View File

@ -320,8 +320,6 @@ int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
int ret = 0;
IO_CODE();
assume_graph_lock(); /* FIXME */
if (!(bs->open_flags & BDRV_O_RDWR)) {
return 0;
}
@ -1908,7 +1906,9 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, ro)) {
if (!ro && bdrv_is_whitelisted(drv, true)) {
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, NULL, NULL);
bdrv_graph_rdunlock_main_loop();
} else {
ret = -ENOTSUP;
}

View File

@ -106,7 +106,9 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
int ret;
/* No write support yet */
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, NULL, errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
return ret;
}

View File

@ -67,7 +67,9 @@ static int cloop_open(BlockDriverState *bs, QDict *options, int flags,
uint32_t offsets_size, max_compressed_block_size = 1, i;
int ret;
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, NULL, errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
return ret;
}

View File

@ -696,8 +696,10 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
const char *protocol_delimiter;
int ret;
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
return ret;
}

View File

@ -452,7 +452,9 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
int64_t offset;
int ret;
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, NULL, errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
return ret;
}

View File

@ -863,11 +863,13 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
if (ret == -EACCES || ret == -EROFS) {
/* Try to degrade to read-only, but if it doesn't work, still use the
* normal error message. */
bdrv_graph_rdlock_main_loop();
if (bdrv_apply_auto_read_only(bs, NULL, NULL) == 0) {
open_flags = (open_flags & ~O_RDWR) | O_RDONLY;
s->fd = glfs_open(s->glfs, gconf->path, open_flags);
ret = s->fd ? 0 : -errno;
}
bdrv_graph_rdunlock_main_loop();
}
s->supports_seek_data = qemu_gluster_test_seek(s->fd);

View File

@ -1925,7 +1925,9 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
/* Check the write protect flag of the LUN if we want to write */
if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) &&
iscsilun->write_protected) {
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, "LUN is write protected", errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
goto out;
}

View File

@ -275,7 +275,8 @@ static bool nbd_client_will_reconnect(BDRVNBDState *s)
* Return failure if the server's advertised options are incompatible with the
* client's needs.
*/
static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp)
static int coroutine_fn GRAPH_RDLOCK
nbd_handle_updated_info(BlockDriverState *bs, Error **errp)
{
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
int ret;

View File

@ -1168,7 +1168,9 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
bdrv_graph_rdlock_main_loop();
r = bdrv_apply_auto_read_only(bs, "rbd snapshots are read-only", errp);
bdrv_graph_rdunlock_main_loop();
if (r < 0) {
goto failed_post_open;
}

View File

@ -163,8 +163,10 @@ bdrv_is_allocated_above(BlockDriverState *bs, BlockDriverState *base,
int coroutine_fn GRAPH_RDLOCK
bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, int64_t bytes);
int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
Error **errp);
int GRAPH_RDLOCK
bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
Error **errp);
bool bdrv_is_read_only(BlockDriverState *bs);
bool bdrv_is_writable(BlockDriverState *bs);
bool bdrv_is_sg(BlockDriverState *bs);