qemu/block
Kevin Wolf 86b1cf3227 block: Separate blk_is_writable() and blk_supports_write_perm()
Currently, blk_is_read_only() tells whether a given BlockBackend can
only be used in read-only mode because its root node is read-only. Some
callers actually try to answer a slightly different question: Is the
BlockBackend configured to be writable, by taking write permissions on
the root node?

This can differ, for example, for CD-ROM devices which don't take write
permissions, but may be backed by a writable image file. scsi-cd allows
write requests to the drive if blk_is_read_only() returns false.
However, the write request will immediately run into an assertion
failure because the write permission is missing.

This patch introduces separate functions for both questions.
blk_supports_write_perm() answers the question whether the block
node/image file can support writable devices, whereas blk_is_writable()
tells whether the BlockBackend is currently configured to be writable.

All calls of blk_is_read_only() are converted to one of the two new
functions.

Fixes: https://bugs.launchpad.net/bugs/1906693
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210118123448.307825-2-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-01-27 20:45:20 +01:00
..
export fuse: Implement hole detection through lseek 2020-12-11 17:52:40 +01:00
monitor qapi: block-stream: add "bottom" argument 2021-01-26 14:36:37 +01:00
accounting.c block/accounting: Use lock guard macros 2020-12-11 17:52:39 +01:00
aio_task.c block: introduce aio task pool 2019-10-10 10:56:17 +02:00
amend.c block/amend: Check whether the node exists 2020-07-27 12:37:25 +02:00
backup-top.c block/block-copy: drop unused argument of block_copy() 2021-01-26 14:36:37 +01:00
backup-top.h qapi: backup: add perf.use-copy-range parameter 2021-01-26 14:36:37 +01:00
backup.c backup: move to block-copy 2021-01-26 14:36:37 +01:00
blkdebug.c block: Fix some code style problems, "foo* bar" should be "foo *bar" 2020-11-09 18:42:47 +01:00
blklogwrites.c block: Inline bdrv_co_block_status_from_*() 2020-09-07 12:31:31 +02:00
blkreplay.c block: Use bdrv_default_perms() 2020-05-18 19:05:25 +02:00
blkverify.c error: Eliminate error_propagate() with Coccinelle, part 2 2020-07-10 15:18:08 +02:00
block-backend.c block: Separate blk_is_writable() and blk_supports_write_perm() 2021-01-27 20:45:20 +01:00
block-copy.c block/block-copy: drop unused argument of block_copy() 2021-01-26 14:36:37 +01:00
block-gen.h scripts: add block-coroutine-wrapper.py 2020-10-05 10:59:06 +01:00
bochs.c block: Use bdrv_default_perms() 2020-05-18 19:05:25 +02:00
cloop.c block: Use bdrv_default_perms() 2020-05-18 19:05:25 +02:00
commit.c block: Return depth level during bdrv_is_allocated_above 2020-10-30 15:21:23 -05:00
copy-on-read.c copy-on-read: skip non-guest reads if no copy needed 2021-01-26 14:36:37 +01:00
copy-on-read.h copy-on-read: add filter drop function 2021-01-26 11:26:54 +01:00
coroutines.h block: Return depth level during bdrv_is_allocated_above 2020-10-30 15:21:23 -05:00
create.c block/create: Do not abort if a block driver is not available 2019-09-13 12:18:37 +02:00
crypto.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
crypto.h nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
curl.c curl: remove compatibility code, require 7.29.0 2021-01-02 21:03:37 +01:00
dirty-bitmap.c block/dirty-bitmap: add bdrv_has_named_bitmaps helper 2020-05-28 13:15:22 -05:00
dmg-bz2.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
dmg-lzfse.c block: Remove unused include 2020-11-09 15:44:21 +01:00
dmg.c block: Fix some code style problems, "foo* bar" should be "foo *bar" 2020-11-09 18:42:47 +01:00
dmg.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
file-posix.c block: report errno when flock fcntl fails 2021-01-26 14:36:37 +01:00
file-win32.c block/file: switch to use qemu_open/qemu_create for improved errors 2020-09-16 10:33:48 +01:00
filter-compress.c block: Inline bdrv_co_block_status_from_*() 2020-09-07 12:31:31 +02:00
gluster.c qapi: Use QAPI_LIST_PREPEND() where possible 2020-12-19 10:20:14 +01:00
io_uring.c io_uring: do not use pointer after free 2020-11-17 12:26:48 +01:00
io.c block: include supported_read_flags into BDS structure 2021-01-26 14:36:37 +01:00
iscsi-opts.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
iscsi.c Remove superfluous timer_del() calls 2021-01-08 15:13:38 +00:00
linux-aio.c misc: Replace zero-length arrays with flexible array member (automatic) 2020-03-16 22:07:42 +01:00
meson.build meson: Propagate gnutls dependency 2021-01-12 12:38:03 +01:00
mirror.c block: Return depth level during bdrv_is_allocated_above 2020-10-30 15:21:23 -05:00
nbd.c block/nbd.c: Add yank feature 2021-01-13 10:21:17 +01:00
nfs.c block/nfs: fix int overflow in nfs_client_open_qdict 2020-12-18 11:48:39 +01:00
null.c block/null: Implement bdrv_get_allocated_file_size 2020-09-07 12:31:31 +02:00
nvme.c block/nvme: Implement fake truncate() coroutine 2020-12-18 12:35:55 +01:00
parallels.c error: Avoid error_propagate() after migrate_add_blocker() 2020-07-10 15:18:08 +02:00
parallels.h Clean up includes 2018-02-09 05:05:11 +01:00
preallocate.c block: introduce preallocate filter 2020-12-18 12:35:55 +01:00
qapi-sysemu.c block: Move system emulator QMP commands to block/qapi-sysemu.c 2020-03-06 17:15:38 +01:00
qapi.c qapi: Use QAPI_LIST_PREPEND() where possible 2020-12-19 10:20:14 +01:00
qcow2-bitmap.c qcow2: Use macros for the L1, refcount and bitmap table entry sizes 2020-09-15 11:05:12 +02:00
qcow2-cache.c core: replace getpagesize() with qemu_real_host_page_size 2019-10-26 15:38:06 +02:00
qcow2-cluster.c qcow2: Fix corruption on write_zeroes with MAY_UNMAP 2020-11-24 11:29:41 +01:00
qcow2-refcount.c qcow2: Make qcow2_free_any_clusters() free only one cluster 2020-09-15 11:05:13 +02:00
qcow2-snapshot.c migration: introduce icount field for snapshots 2020-10-06 08:34:49 +02:00
qcow2-threads.c qcow2: add zstd cluster compression 2020-05-13 14:20:31 +02:00
qcow2.c Remove superfluous timer_del() calls 2021-01-08 15:13:38 +00:00
qcow2.h block: Fix some code style problems, "foo* bar" should be "foo *bar" 2020-11-09 18:42:47 +01:00
qcow.c block/qcow: remove runtime opts 2020-09-15 11:05:13 +02:00
qed-check.c block/qed: add missed coroutine_fn markers 2019-04-30 15:29:00 +02:00
qed-cluster.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-l2-cache.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-table.c block/qed: add missed coroutine_fn markers 2019-04-30 15:29:00 +02:00
qed.c qapi: Smooth another visitor error checking pattern 2020-07-10 15:18:08 +02:00
qed.h qed: Simplify backing reads 2020-07-06 10:34:14 +02:00
quorum.c quorum: Implement bdrv_co_pwrite_zeroes() 2020-12-18 12:35:55 +01:00
raw-format.c error: Eliminate error_propagate() with Coccinelle, part 2 2020-07-10 15:18:08 +02:00
rbd.c qobject: Change qobject_to_json()'s value to GString 2020-12-19 10:38:43 +01:00
replication.c qapi: backup: add max-chunk and max-workers to x-perf struct 2021-01-26 14:36:37 +01:00
sheepdog.c block: deprecate the sheepdog block driver 2020-10-15 16:06:28 +02:00
snapshot.c block/snapshot: Fix fallback 2020-09-07 12:31:31 +02:00
ssh.c qapi: Smooth another visitor error checking pattern 2020-07-10 15:18:08 +02:00
stream.c block: apply COR-filter to block-stream jobs 2021-01-26 14:36:37 +01:00
throttle-groups.c block/throttle-groups: Use lock guard macros 2020-12-11 17:52:39 +01:00
throttle.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
trace-events block/nvme: Use unsigned integer for queue counter/size 2020-11-03 19:06:21 +00:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
vdi.c error: Avoid error_propagate() after migrate_add_blocker() 2020-07-10 15:18:08 +02:00
vhdx-endian.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vhdx-log.c block: Add flags to bdrv(_co)_truncate() 2020-04-30 17:51:07 +02:00
vhdx.c block/vhdx: Support vhdx image only with 512 bytes logical sector size 2020-09-15 11:05:13 +02:00
vhdx.h block/vhdx: Use IEC binary prefixes for size constants 2019-04-30 15:29:00 +02:00
vmdk.c vmdk: fix maybe uninitialized warnings 2020-10-13 13:33:45 +02:00
vpc.c block/vpc: Use sizeof() instead of HEADER_SIZE for footer size 2020-12-18 12:43:30 +01:00
vvfat.c block/vvfat: Fix bad printf format specifiers 2020-11-03 16:24:56 +01:00
win32-aio.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
write-threshold.c qapi: Drop qapi_event_send_FOO()'s Error ** argument 2018-08-28 18:21:38 +02:00