[Qemu-devel] [PATCH 21/55] block: Revert entanglement of bdrv_is_inserted() with tray status

[Markus Armbruster <armbru@redhat.com>]

Commit 4be9762a changed bdrv_is_inserted() to fail when the tray is
open.  Unfortunately, there are two different kinds of users, with
conflicting needs.

1. Device models using bdrv_eject(), currently ide-cd and scsi-cd.
They expect bdrv_is_inserted() to reflect the tray status.  Commit
4be9762a makes them happy.

2. Code that wants to know whether a BlockDriverState has media, such
as find_image_format(), bdrv_flush_all().  Commit 4be9762a makes them
unhappy.  In particular, it breaks flush on VM stop for media ejected
by the guest.

Revert the change to bdrv_is_inserted().  Check the tray status in the
device models instead.

Note on IDE: Since only ATAPI devices have a tray, and they don't
accept ATA commands since the recent commit "ide: Reject ATA commands
specific to drive kinds", checking in atapi.c suffices.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 block.c        |    7 +++----
 hw/ide/atapi.c |   15 ++++++++-------
 hw/scsi-disk.c |   12 +++++++++---
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/block.c b/block.c
index 6727274..2b1eb4d 100644
--- a/block.c
+++ b/block.c
@@ -2734,13 +2734,12 @@ void qemu_aio_release(void *p)
 int bdrv_is_inserted(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
-    int ret;
+
     if (!drv)
         return 0;
     if (!drv->bdrv_is_inserted)
-        return !bs->tray_open;
-    ret = drv->bdrv_is_inserted(bs);
-    return ret;
+        return 1;
+    return drv->bdrv_is_inserted(bs);
 }
 
 /**
diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 96f7c31..08e1a7a 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -73,7 +73,7 @@ static void lba_to_msf(uint8_t *buf, int lba)
 
 static inline int media_present(IDEState *s)
 {
-    return (s->nb_sectors > 0);
+    return !s->tray_open && s->nb_sectors > 0;
 }
 
 /* XXX: DVDs that could fit on a CD will be reported as a CD */
@@ -1066,20 +1066,21 @@ static const struct {
     [ 0x03 ] = { cmd_request_sense,                 ALLOW_UA },
     [ 0x12 ] = { cmd_inquiry,                       ALLOW_UA },
     [ 0x1a ] = { cmd_mode_sense, /* (6) */          0 },
-    [ 0x1b ] = { cmd_start_stop_unit,               0 },
+    [ 0x1b ] = { cmd_start_stop_unit,               0 }, /* [1] */
     [ 0x1e ] = { cmd_prevent_allow_medium_removal,  0 },
     [ 0x25 ] = { cmd_read_cdvd_capacity,            CHECK_READY },
-    [ 0x28 ] = { cmd_read, /* (10) */               0 },
+    [ 0x28 ] = { cmd_read, /* (10) */               CHECK_READY },
     [ 0x2b ] = { cmd_seek,                          CHECK_READY },
     [ 0x43 ] = { cmd_read_toc_pma_atip,             CHECK_READY },
     [ 0x46 ] = { cmd_get_configuration,             ALLOW_UA },
     [ 0x4a ] = { cmd_get_event_status_notification, ALLOW_UA },
     [ 0x5a ] = { cmd_mode_sense, /* (10) */         0 },
-    [ 0xa8 ] = { cmd_read, /* (12) */               0 },
-    [ 0xad ] = { cmd_read_dvd_structure,            0 },
+    [ 0xa8 ] = { cmd_read, /* (12) */               CHECK_READY },
+    [ 0xad ] = { cmd_read_dvd_structure,            CHECK_READY },
     [ 0xbb ] = { cmd_set_speed,                     0 },
     [ 0xbd ] = { cmd_mechanism_status,              0 },
-    [ 0xbe ] = { cmd_read_cd,                       0 },
+    [ 0xbe ] = { cmd_read_cd,                       CHECK_READY },
+    /* [1] handler detects and reports not ready condition itself */
 };
 
 void ide_atapi_cmd(IDEState *s)
@@ -1115,7 +1116,7 @@ void ide_atapi_cmd(IDEState *s)
      * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close
      * states rely on this behavior.
      */
-    if (bdrv_is_inserted(s->bs) && s->cdrom_changed) {
+    if (!s->tray_open && bdrv_is_inserted(s->bs) && s->cdrom_changed) {
         ide_atapi_cmd_error(s, SENSE_NOT_READY, ASC_MEDIUM_NOT_PRESENT);
 
         s->cdrom_changed = 0;
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index fc36327..207a868 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -189,6 +189,9 @@ static void scsi_read_data(SCSIRequest *req)
     if (n > SCSI_DMA_BUF_SIZE / 512)
         n = SCSI_DMA_BUF_SIZE / 512;
 
+    if (s->tray_open) {
+        scsi_read_complete(r, -ENOMEDIUM);
+    }
     r->iov.iov_len = n * 512;
     qemu_iovec_init_external(&r->qiov, &r->iov, 1);
     r->req.aiocb = bdrv_aio_readv(s->bs, r->sector, &r->qiov, n,
@@ -287,6 +290,9 @@ static void scsi_write_data(SCSIRequest *req)
 
     n = r->iov.iov_len / 512;
     if (n) {
+        if (s->tray_open) {
+            scsi_write_complete(r, -ENOMEDIUM);
+        }
         qemu_iovec_init_external(&r->qiov, &r->iov, 1);
         r->req.aiocb = bdrv_aio_writev(s->bs, r->sector, &r->qiov, n,
                                    scsi_write_complete, r);
@@ -841,7 +847,7 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
 
     switch (req->cmd.buf[0]) {
     case TEST_UNIT_READY:
-        if (!bdrv_is_inserted(s->bs))
+        if (s->tray_open || !bdrv_is_inserted(s->bs))
             goto not_ready;
 	break;
     case REQUEST_SENSE:
@@ -978,7 +984,7 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
         break;
     case REZERO_UNIT:
         DPRINTF("Rezero Unit\n");
-        if (!bdrv_is_inserted(s->bs)) {
+        if (s->tray_open || !bdrv_is_inserted(s->bs)) {
             goto not_ready;
         }
         break;
@@ -990,7 +996,7 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
     return buflen;
 
 not_ready:
-    if (!bdrv_is_inserted(s->bs)) {
+    if (s->tray_open || !bdrv_is_inserted(s->bs)) {
         scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(NO_MEDIUM));
     } else {
         scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(LUN_NOT_READY));
-- 
1.7.2.3