diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2021-01-18 13:34:47 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2021-01-27 20:45:20 +0100 |
| commit | 86b1cf322789b79c8ace977430ac6a443d491cc0 (patch) | |
| tree | baac83ce91c3f7ea7c7ec61fa9249b205459b387 /include/sysemu | |
| parent | bf159f0bdc7b8e7aa8342dedb3829ca744c1b612 (diff) | |
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>
Diffstat (limited to 'include/sysemu')
| -rw-r--r-- | include/sysemu/block-backend.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 8203d7f6f9..880e903293 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -191,7 +191,8 @@ BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, int error); void blk_error_action(BlockBackend *blk, BlockErrorAction action, bool is_read, int error); -bool blk_is_read_only(BlockBackend *blk); +bool blk_supports_write_perm(BlockBackend *blk); +bool blk_is_writable(BlockBackend *blk); bool blk_is_sg(BlockBackend *blk); bool blk_enable_write_cache(BlockBackend *blk); void blk_set_enable_write_cache(BlockBackend *blk, bool wce); |