From 018f9dea9c905506c49f8f37c018470dddfc50f1 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 29 Sep 2023 16:51:53 +0200 Subject: [PATCH] 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 Message-ID: <20230929145157.45443-19-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 4 ++-- block/bochs.c | 2 ++ block/cloop.c | 2 ++ block/curl.c | 2 ++ block/dmg.c | 2 ++ block/gluster.c | 2 ++ block/iscsi.c | 2 ++ block/nbd.c | 3 ++- block/rbd.c | 2 ++ include/block/block-io.h | 6 ++++-- 10 files changed, 22 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index fd348f5069..2ac7406c77 100644 --- a/block.c +++ b/block.c @@ -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; } diff --git a/block/bochs.c b/block/bochs.c index 66e7a58e5e..8c659fa9b9 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -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; } diff --git a/block/cloop.c b/block/cloop.c index 835a0fe3da..773d7918be 100644 --- a/block/cloop.c +++ b/block/cloop.c @@ -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; } diff --git a/block/curl.c b/block/curl.c index 0fc42d03d7..419f7c89ef 100644 --- a/block/curl.c +++ b/block/curl.c @@ -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; } diff --git a/block/dmg.c b/block/dmg.c index 06a0244a9c..38ee72bbe5 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -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; } diff --git a/block/gluster.c b/block/gluster.c index ad5fadbe79..cc74af06dc 100644 --- a/block/gluster.c +++ b/block/gluster.c @@ -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); diff --git a/block/iscsi.c b/block/iscsi.c index 5640c8b565..2ff14b7472 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -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; } diff --git a/block/nbd.c b/block/nbd.c index 52ebc8b2f5..b9d4f935e0 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -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; diff --git a/block/rbd.c b/block/rbd.c index 073bc92e39..84bb2fa5d7 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -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; } diff --git a/include/block/block-io.h b/include/block/block-io.h index 2c0c7b1906..e051e9bed6 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -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);