Commit e5e78550 authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf
Browse files

blockdev: Separate BB name management 



Introduce separate functions (monitor_add_blk() and
monitor_remove_blk()) which set or unset a BB name. Since the name is
equivalent to the monitor's reference to a BB, adding a name the same as
declaring the BB to be monitor-owned and removing it revokes this
status, hence the function names.

Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 2cf22d6a

block/block-backend.c

+61 −31
Original line number Diff line number Diff line
@@ -90,30 +90,17 @@ BlockBackend *blk_new(const char *name, Error **errp) 
{

    BlockBackend *blk;



    assert(name && name[0]);

    if (!id_wellformed(name)) {

        error_setg(errp, "Invalid device name");

        return NULL;

    }

    if (blk_by_name(name)) {

        error_setg(errp, "Device with id '%s' already exists", name);

        return NULL;

    }

    if (bdrv_find_node(name)) {

        error_setg(errp,

                   "Device name '%s' conflicts with an existing node name",

                   name);

        return NULL;

    }



    blk = g_new0(BlockBackend, 1);

    blk->name = g_strdup(name);

    blk->refcnt = 1;

    notifier_list_init(&blk->remove_bs_notifiers);

    notifier_list_init(&blk->insert_bs_notifiers);



    QTAILQ_INSERT_TAIL(&block_backends, blk, link);

    QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link);



    if (!monitor_add_blk(blk, name, errp)) {

        blk_unref(blk);

        return NULL;

    }



    return blk;

}
@@ -174,7 +161,10 @@ BlockBackend *blk_new_open(const char *name, const char *filename, 


static void blk_delete(BlockBackend *blk)

{

    monitor_remove_blk(blk);



    assert(!blk->refcnt);

    assert(!blk->name);

    assert(!blk->dev);

    if (blk->bs) {

        blk_remove_bs(blk);
@@ -185,15 +175,7 @@ static void blk_delete(BlockBackend *blk) 
        g_free(blk->root_state.throttle_group);

        throttle_group_unref(blk->root_state.throttle_state);

    }



    /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */

    if (blk->name[0]) {

        QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);

    }

    g_free(blk->name);



    QTAILQ_REMOVE(&block_backends, blk, link);



    drive_info_del(blk->legacy_dinfo);

    block_acct_cleanup(&blk->stats);

    g_free(blk);
@@ -279,14 +261,63 @@ BlockBackend *blk_next(BlockBackend *blk) 
               : QTAILQ_FIRST(&monitor_block_backends);

}



/*

 * Add a BlockBackend into the list of backends referenced by the monitor, with

 * the given @name acting as the handle for the monitor.

 * Strictly for use by blockdev.c.

 *

 * @name must not be null or empty.

 *

 * Returns true on success and false on failure. In the latter case, an Error

 * object is returned through @errp.

 */

bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp)

{

    assert(!blk->name);

    assert(name && name[0]);



    if (!id_wellformed(name)) {

        error_setg(errp, "Invalid device name");

        return false;

    }

    if (blk_by_name(name)) {

        error_setg(errp, "Device with id '%s' already exists", name);

        return false;

    }

    if (bdrv_find_node(name)) {

        error_setg(errp,

                   "Device name '%s' conflicts with an existing node name",

                   name);

        return false;

    }



    blk->name = g_strdup(name);

    QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link);

    return true;

}



/*

 * Remove a BlockBackend from the list of backends referenced by the monitor.

 * Strictly for use by blockdev.c.

 */

void monitor_remove_blk(BlockBackend *blk)

{

    if (!blk->name) {

        return;

    }



    QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);

    g_free(blk->name);

    blk->name = NULL;

}



/*

 * Return @blk's name, a non-null string.

 * Wart: the name is empty iff @blk has been hidden with

 * blk_hide_on_behalf_of_hmp_drive_del().

 * Returns an empty string iff @blk is not referenced by the monitor.

 */

const char *blk_name(BlockBackend *blk)

{

    return blk->name;

    return blk->name ?: "";

}



/*
@@ -377,8 +408,7 @@ BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo) 
 */

void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)

{

    QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);

    blk->name[0] = 0;

    monitor_remove_blk(blk);

    if (blk->bs) {

        bdrv_make_anon(blk->bs);

    }

include/sysemu/block-backend.h

+2 −0
Original line number Diff line number Diff line
@@ -71,6 +71,8 @@ void blk_remove_all_bs(void); 
const char *blk_name(BlockBackend *blk);

BlockBackend *blk_by_name(const char *name);

BlockBackend *blk_next(BlockBackend *blk);

bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);

void monitor_remove_blk(BlockBackend *blk);



BlockDriverState *blk_bs(BlockBackend *blk);

void blk_remove_bs(BlockBackend *blk);