From 5641703ef043ffc10ab9ab0e15f29ccbe30df7a5 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sat, 14 Nov 2020 12:51:03 +0100
Subject: rumpdisk: Support opening a device several times
* rumpdisk/block-rump.c (struct block_data): Make taken field an integer
instead of a boolean.
(device_open): When search_bd succeeds, set a new reference and return a
new port right. Separate out io_return_t err, int fd, and int ret to avoid
confusions. Simplify the error handling path.
(device_close): Decrement reference and close rump disk only when
reaching zero. Also destroy our port.
---
rumpdisk/block-rump.c | 113 ++++++++++++++++++++++++++------------------------
1 file changed, 58 insertions(+), 55 deletions(-)
(limited to 'rumpdisk')
diff --git a/rumpdisk/block-rump.c b/rumpdisk/block-rump.c
index afd91d49..dc7fbdd9 100644
--- a/rumpdisk/block-rump.c
+++ b/rumpdisk/block-rump.c
@@ -53,7 +53,7 @@ struct block_data
char name[DISK_NAME_LEN]; /* eg /dev/wd0 */
off_t media_size; /* total block device size */
uint32_t block_size; /* size in bytes of 1 sector */
- bool taken; /* simple refcount */
+ int taken; /* refcount */
struct block_data *next;
};
@@ -141,8 +141,19 @@ static io_return_t
device_close (void *d)
{
struct block_data *bd = d;
+ io_return_t err;
- return rump_errno2host (rump_sys_close (bd->rump_fd));
+ bd->taken--;
+ if (bd->taken)
+ return D_SUCCESS;
+
+ err = rump_errno2host (rump_sys_close (bd->rump_fd));
+ if (err != D_SUCCESS)
+ return err;
+
+ ports_port_deref (bd);
+ ports_destroy_right (bd);
+ return D_SUCCESS;
}
static void
@@ -169,8 +180,9 @@ device_open (mach_port_t reply_port, mach_msg_type_name_t reply_port_type,
dev_mode_t mode, char *name, device_t * devp,
mach_msg_type_name_t * devicePoly)
{
- io_return_t err = D_ALREADY_OPEN;
- struct block_data *bd = NULL;
+ io_return_t err;
+ int ret, fd;
+ struct block_data *bd;
char dev_name[DISK_NAME_LEN];
off_t media_size;
uint32_t block_size;
@@ -178,67 +190,58 @@ device_open (mach_port_t reply_port, mach_msg_type_name_t reply_port_type,
if (! is_disk_device (name, 8))
return D_NO_SUCH_DEVICE;
- translate_name (dev_name, DISK_NAME_LEN, name);
-
/* Find previous device or open if new */
bd = search_bd (name);
- if (!bd)
+ if (bd)
{
- err = machdev_create_device_port (sizeof (*bd), &bd);
-
- snprintf (bd->name, DISK_NAME_LEN, "%s", name);
- bd->mode = mode;
- bd->device.emul_data = bd;
- bd->device.emul_ops = &rump_block_emulation_ops;
-
- err = rump_sys_open (dev_name, dev_mode_to_rump_mode (bd->mode));
- if (err < 0)
- {
- err = rump_errno2host (errno);
- goto out;
- }
- bd->rump_fd = err;
-
- err = rump_sys_ioctl (bd->rump_fd, DIOCGMEDIASIZE, &media_size);
- if (err < 0)
- {
- mach_print ("DIOCGMEDIASIZE ioctl fails\n");
- err = rump_errno2host (errno);
- goto out;
- }
-
- err = rump_sys_ioctl (bd->rump_fd, DIOCGSECTORSIZE, &block_size);
- if (err < 0)
- {
- mach_print ("DIOCGSECTORSIZE ioctl fails\n");
- err = rump_errno2host (errno);
- goto out;
- }
- bd->media_size = media_size;
- bd->block_size = block_size;
-
- err = D_SUCCESS;
+ bd->taken++;
+ *devp = ports_get_right (bd);
+ *devicePoly = MACH_MSG_TYPE_MAKE_SEND;
+ return D_SUCCESS;
}
-out:
- if (err)
+ translate_name (dev_name, DISK_NAME_LEN, name);
+
+ fd = rump_sys_open (dev_name, dev_mode_to_rump_mode (mode));
+ if (fd < 0)
+ return rump_errno2host (errno);
+
+ ret = rump_sys_ioctl (fd, DIOCGMEDIASIZE, &media_size);
+ if (ret < 0)
{
- if (bd)
- {
- ports_port_deref (bd);
- ports_destroy_right (bd);
- bd = NULL;
- }
+ mach_print ("DIOCGMEDIASIZE ioctl fails\n");
+ return rump_errno2host (errno);
}
- if (bd)
+ ret = rump_sys_ioctl (fd, DIOCGSECTORSIZE, &block_size);
+ if (ret < 0)
{
- bd->next = block_head;
- block_head = bd;
- *devp = ports_get_right (bd);
- *devicePoly = MACH_MSG_TYPE_MAKE_SEND;
+ mach_print ("DIOCGSECTORSIZE ioctl fails\n");
+ return rump_errno2host (errno);
}
- return err;
+
+ err = machdev_create_device_port (sizeof (*bd), &bd);
+ if (err != 0)
+ {
+ rump_sys_close (fd);
+ return err;
+ }
+
+ bd->taken = 1;
+ snprintf (bd->name, DISK_NAME_LEN, "%s", name);
+ bd->rump_fd = fd;
+ bd->mode = mode;
+ bd->device.emul_data = bd;
+ bd->device.emul_ops = &rump_block_emulation_ops;
+ bd->media_size = media_size;
+ bd->block_size = block_size;
+
+ bd->next = block_head;
+ block_head = bd;
+
+ *devp = ports_get_right (bd);
+ *devicePoly = MACH_MSG_TYPE_MAKE_SEND;
+ return D_SUCCESS;
}
static io_return_t
--
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