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authorKevin Wolf <kwolf@redhat.com>2021-01-18 13:34:47 +0100
committerKevin Wolf <kwolf@redhat.com>2021-01-27 20:45:20 +0100
commit86b1cf322789b79c8ace977430ac6a443d491cc0 (patch)
treebaac83ce91c3f7ea7c7ec61fa9249b205459b387 /hw/scsi
parentbf159f0bdc7b8e7aa8342dedb3829ca744c1b612 (diff)
downloadqemu-arm-86b1cf322789b79c8ace977430ac6a443d491cc0.tar.gz
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 'hw/scsi')
-rw-r--r--hw/scsi/scsi-disk.c10
-rw-r--r--hw/scsi/scsi-generic.c4
2 files changed, 7 insertions, 7 deletions
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 29504ea081..ed52fcd49f 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1270,7 +1270,7 @@ static int scsi_disk_emulate_mode_sense(SCSIDiskReq *r, uint8_t *outbuf)
if (s->qdev.type == TYPE_DISK) {
dev_specific_param = s->features & (1 << SCSI_DISK_F_DPOFUA) ? 0x10 : 0;
- if (blk_is_read_only(s->qdev.conf.blk)) {
+ if (!blk_is_writable(s->qdev.conf.blk)) {
dev_specific_param |= 0x80; /* Readonly. */
}
} else {
@@ -1704,7 +1704,7 @@ static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
goto invalid_param_len;
}
- if (blk_is_read_only(s->qdev.conf.blk)) {
+ if (!blk_is_writable(s->qdev.conf.blk)) {
block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
return;
@@ -1795,7 +1795,7 @@ static void scsi_disk_emulate_write_same(SCSIDiskReq *r, uint8_t *inbuf)
return;
}
- if (blk_is_read_only(s->qdev.conf.blk)) {
+ if (!blk_is_writable(s->qdev.conf.blk)) {
scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
return;
}
@@ -2207,7 +2207,7 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
case WRITE_VERIFY_10:
case WRITE_VERIFY_12:
case WRITE_VERIFY_16:
- if (blk_is_read_only(s->qdev.conf.blk)) {
+ if (!blk_is_writable(s->qdev.conf.blk)) {
scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
return 0;
}
@@ -2380,7 +2380,7 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
}
}
- read_only = blk_is_read_only(s->qdev.conf.blk);
+ read_only = !blk_supports_write_perm(s->qdev.conf.blk);
if (dev->type == TYPE_ROM) {
read_only = true;
}
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index 9740f7e36a..ab220141f5 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -306,7 +306,7 @@ static void scsi_read_complete(void * opaque, int ret)
* readonly.
*/
if ((s->type == TYPE_DISK || s->type == TYPE_TAPE || s->type == TYPE_ZBC) &&
- blk_is_read_only(s->conf.blk) &&
+ !blk_is_writable(s->conf.blk) &&
(r->req.cmd.buf[0] == MODE_SENSE ||
r->req.cmd.buf[0] == MODE_SENSE_10) &&
(r->req.cmd.buf[1] & 0x8) == 0) {
@@ -694,7 +694,7 @@ static void scsi_generic_realize(SCSIDevice *s, Error **errp)
return;
}
if (!blkconf_apply_backend_options(&s->conf,
- blk_is_read_only(s->conf.blk),
+ !blk_supports_write_perm(s->conf.blk),
true, errp)) {
return;
}