iscsi: fix deadlock during login
PATCH v2 1/1 iscsi: fix deadlock during login
If the connection is interrupted before the first login is successfully completed qemu-kvm is waiting forever in qemu_aio_wait().
This is fixed by performing an sync login to the target. If the connection breaks after the first successful login errors are handled internally by libiscsi.
v2:
changed the complete iscsi_open routine to sync tasks.
Signed-off-by Peter Lieven <[email protected]>
--- block/iscsi.c | 251 ++++++++++++++++----------------------------------------- 1 file changed, 70 insertions(+), 181 deletions(-)
block/iscsi.c +70 -181
@@ -65,13 +65,6 @@ typedef struct IscsiAIOCB {#endif } IscsiAIOCB; -struct IscsiTask { -IscsiLun *iscsilun; -BlockDriverState *bs; -int status; -int complete; -}; -static void iscsi_bh_cb (void *p) {
@@ -665,163 +658,6 @@ iscsi_getlength(BlockDriverState *bs)return len; } -static void -iscsi_readcapacity16_cb (struct iscsi_context *iscsi,int status, -void *command_data,void *opaque) -{ -struct IscsiTask *itask = opaque; -struct scsi_readcapacity16 *rc16; -struct scsi_task *task = command_data; - -if (status !=0 ) { -error_report ("iSCSI: Failed to read capacity of iSCSI lun. %s" , -iscsi_get_error (iscsi)); - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - rc16 =scsi_datain_unmarshall (task); -if (rc16 ==NULL ) { -error_report ("iSCSI: Failed to unmarshall readcapacity16 data." ); - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - itask->iscsilun->block_size = rc16->block_length; - itask->iscsilun->num_blocks = rc16->returned_lba +1 ; - itask->bs->total_sectors = itask->iscsilun->num_blocks * - itask->iscsilun->block_size /BDRV_SECTOR_SIZE ; - - itask->status =0 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -} - -static void -iscsi_readcapacity10_cb (struct iscsi_context *iscsi,int status, -void *command_data,void *opaque) -{ -struct IscsiTask *itask = opaque; -struct scsi_readcapacity10 *rc10; -struct scsi_task *task = command_data; - -if (status !=0 ) { -error_report ("iSCSI: Failed to read capacity of iSCSI lun. %s" , -iscsi_get_error (iscsi)); - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - rc10 =scsi_datain_unmarshall (task); -if (rc10 ==NULL ) { -error_report ("iSCSI: Failed to unmarshall readcapacity10 data." ); - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - itask->iscsilun->block_size = rc10->block_size; -if (rc10->lba ==0 ) { -/* blank disk loaded */ - itask->iscsilun->num_blocks =0 ; - }else { - itask->iscsilun->num_blocks = rc10->lba +1 ; - } - itask->bs->total_sectors = itask->iscsilun->num_blocks * - itask->iscsilun->block_size /BDRV_SECTOR_SIZE ; - - itask->status =0 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -} - -static void -iscsi_inquiry_cb (struct iscsi_context *iscsi,int status,void *command_data, -void *opaque) -{ -struct IscsiTask *itask = opaque; -struct scsi_task *task = command_data; -struct scsi_inquiry_standard *inq; - -if (status !=0 ) { - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - inq =scsi_datain_unmarshall (task); -if (inq ==NULL ) { -error_report ("iSCSI: Failed to unmarshall inquiry data." ); - itask->status =1 ; - itask->complete =1 ; -scsi_free_scsi_task (task); -return ; - } - - itask->iscsilun->type = inq->periperal_device_type; - -scsi_free_scsi_task (task); - -switch (itask->iscsilun->type) { -case TYPE_DISK : - task =iscsi_readcapacity16_task (iscsi, itask->iscsilun->lun, - iscsi_readcapacity16_cb, opaque); -if (task ==NULL ) { -error_report ("iSCSI: failed to send readcapacity16 command." ); - itask->status =1 ; - itask->complete =1 ; -return ; - } -break ; -case TYPE_ROM : - task =iscsi_readcapacity10_task (iscsi, itask->iscsilun->lun, -0 ,0 , - iscsi_readcapacity10_cb, opaque); -if (task ==NULL ) { -error_report ("iSCSI: failed to send readcapacity16 command." ); - itask->status =1 ; - itask->complete =1 ; -return ; - } -break ; -default : - itask->status =0 ; - itask->complete =1 ; - } -} - -static void -iscsi_connect_cb (struct iscsi_context *iscsi,int status,void *command_data, -void *opaque) -{ -struct IscsiTask *itask = opaque; -struct scsi_task *task; - -if (status !=0 ) { - itask->status =1 ; - itask->complete =1 ; -return ; - } - - task =iscsi_inquiry_task (iscsi, itask->iscsilun->lun, -0 ,0 ,36 , - iscsi_inquiry_cb, opaque); -if (task ==NULL ) { -error_report ("iSCSI: failed to send inquiry command." ); - itask->status =1 ; - itask->complete =1 ; -return ; - } -} -static int parse_chap (struct iscsi_context *iscsi,const char *target) {QemuOptsList *list;
@@ -934,7 +770,10 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)IscsiLun *iscsilun = bs->opaque;struct iscsi_context *iscsi =NULL ;struct iscsi_url *iscsi_url =NULL ; -struct IscsiTask task; +struct scsi_task *task =NULL ; +struct scsi_inquiry_standard *inq =NULL ; +struct scsi_readcapacity10 *rc10 =NULL ; +struct scsi_readcapacity16 *rc16 =NULL ;char *initiator_name =NULL ;int ret;
@@ -998,33 +837,80 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)/* check if we got HEADER_DIGEST via the options */ parse_header_digest (iscsi, iscsi_url->target); - task.iscsilun = iscsilun; - task.status =0 ; - task.complete =0 ; - task.bs = bs; +if (iscsi_full_connect_sync (iscsi, iscsi_url->portal, iscsi_url->lun) !=0 ) { +error_report ("iSCSI: Failed to connect to LUN : %s" , +iscsi_get_error (iscsi)); + ret = -EINVAL ; + goto out; + } iscsilun->iscsi = iscsi; iscsilun->lun = iscsi_url->lun; -if (iscsi_full_connect_async (iscsi, iscsi_url->portal, iscsi_url->lun, - iscsi_connect_cb, &task) - !=0 ) { -error_report ("iSCSI: Failed to start async connect." ); + task =iscsi_inquiry_sync (iscsi, iscsilun->lun,0 ,0 ,36 ); + +if (task ==NULL || task->status !=SCSI_STATUS_GOOD ) { +error_report ("iSCSI: failed to send inquiry command." ); ret = -EINVAL ; goto out; } - -while (!task.complete) { -iscsi_set_events (iscsilun); -qemu_aio_wait (); - } -if (task.status !=0 ) { -error_report ("iSCSI: Failed to connect to LUN : %s" , -iscsi_get_error (iscsi)); + + inq =scsi_datain_unmarshall (task); +if (inq ==NULL ) { +error_report ("iSCSI: Failed to unmarshall inquiry data." ); ret = -EINVAL ; goto out; } + iscsilun->type = inq->periperal_device_type; + +scsi_free_scsi_task (task); + +switch (iscsilun->type) { +case TYPE_DISK : + task =iscsi_readcapacity16_sync (iscsi, iscsilun->lun); +if (task ==NULL || task->status !=SCSI_STATUS_GOOD ) { +error_report ("iSCSI: failed to send readcapacity16 command." ); + ret = -EINVAL ; + goto out; + } + rc16 =scsi_datain_unmarshall (task); +if (rc16 ==NULL ) { +error_report ("iSCSI: Failed to unmarshall readcapacity16 data." ); + ret = -EINVAL ; + goto out; + } + iscsilun->block_size = rc16->block_length; + iscsilun->num_blocks = rc16->returned_lba +1 ; +break ; +case TYPE_ROM : + task =iscsi_readcapacity10_sync (iscsi, iscsilun->lun,0 ,0 ); +if (task ==NULL || task->status !=SCSI_STATUS_GOOD ) { +error_report ("iSCSI: failed to send readcapacity10 command." ); + ret = -EINVAL ; + goto out; + } + rc10 =scsi_datain_unmarshall (task); +if (rc10 ==NULL ) { +error_report ("iSCSI: Failed to unmarshall readcapacity10 data." ); + ret = -EINVAL ; + goto out; + } + iscsilun->block_size = rc10->block_size; +if (rc10->lba ==0 ) { +/* blank disk loaded */ + iscsilun->num_blocks =0 ; + }else { + iscsilun->num_blocks = rc10->lba +1 ; + } +break ; +default : +break ; + } + + bs->total_sectors = iscsilun->num_blocks * + iscsilun->block_size /BDRV_SECTOR_SIZE ; +/* Medium changer or tape. We dont have any emulation for this so this must * be sg ioctl compatible. We force it to be sg, otherwise qemu will try * to read from the device to guess the image format.
@@ -1043,6 +929,9 @@ out:if (iscsi_url !=NULL ) {iscsi_destroy_url (iscsi_url); } +if (task !=NULL ) { +scsi_free_scsi_task (task); + }if (ret) {if (iscsi !=NULL ) {
Signature · 1 line
1.7.9.5
Paolo Bonzini
AppliedIl 17/11/2012 14:37, Peter Lieven ha scritto:
Quoted 9 lines
If the connection is interrupted before the first login is successfully completed qemu-kvm is waiting forever in
qemu_aio_wait().This is fixed by performing an sync login to the target. If the connection breaks after the first successful login errors are handled internally by libiscsi.
v2:
changed the completeiscsi_openroutine to sync tasks.
Applied to scsi-next branch, thanks.
Paolo