diff options
author | Mike Christie <michaelc@cs.wisc.edu> | 2006-05-30 05:37:28 (GMT) |
---|---|---|
committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2006-06-05 23:12:25 (GMT) |
commit | 3219e5294150aee7d389e19029f49b44fb6b5c9f (patch) | |
tree | 44236fd9f2eb40d5622cadb126e9f2672b129486 /drivers/scsi/libiscsi.c | |
parent | 040515f53c09047c76ad074dc6a280984dc84b04 (diff) | |
download | linux-3219e5294150aee7d389e19029f49b44fb6b5c9f.tar.xz |
[SCSI] iscsi: fix writepsace race
We can race and misset the suspend bit if iscsi_write_space is
called then iscsi_send returns with a failure indicating
there is no space.
To handle this this patch returns a error upwards allowing xmitworker
to decide if we need to try and transmit again. For the no
write space case xmitworker will not retry, and instead
let iscsi_write_space queue it back up if needed (this relies
on the work queue code to properly requeue us if needed).
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/libiscsi.c')
-rw-r--r-- | drivers/scsi/libiscsi.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 256b87a..2673a11 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -513,10 +513,11 @@ EXPORT_SYMBOL_GPL(iscsi_conn_failure); static int iscsi_data_xmit(struct iscsi_conn *conn) { struct iscsi_transport *tt; + int rc = 0; if (unlikely(conn->suspend_tx)) { debug_scsi("conn %d Tx suspended!\n", conn->id); - return 0; + return -ENODATA; } tt = conn->session->tt; @@ -536,13 +537,15 @@ static int iscsi_data_xmit(struct iscsi_conn *conn) BUG_ON(conn->ctask && conn->mtask); if (conn->ctask) { - if (tt->xmit_cmd_task(conn, conn->ctask)) + rc = tt->xmit_cmd_task(conn, conn->ctask); + if (rc) goto again; /* done with this in-progress ctask */ conn->ctask = NULL; } if (conn->mtask) { - if (tt->xmit_mgmt_task(conn, conn->mtask)) + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) goto again; /* done with this in-progress mtask */ conn->mtask = NULL; @@ -556,7 +559,8 @@ static int iscsi_data_xmit(struct iscsi_conn *conn) list_add_tail(&conn->mtask->running, &conn->mgmt_run_list); spin_unlock_bh(&conn->session->lock); - if (tt->xmit_mgmt_task(conn, conn->mtask)) + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) goto again; } /* done with this mtask */ @@ -574,7 +578,8 @@ static int iscsi_data_xmit(struct iscsi_conn *conn) if (list_empty(&conn->ctask->running)) list_add_tail(&conn->ctask->running, &conn->run_list); spin_unlock_bh(&conn->session->lock); - if (tt->xmit_cmd_task(conn, conn->ctask)) + rc = tt->xmit_cmd_task(conn, conn->ctask); + if (rc) goto again; } /* done with this ctask */ @@ -588,32 +593,34 @@ static int iscsi_data_xmit(struct iscsi_conn *conn) list_add_tail(&conn->mtask->running, &conn->mgmt_run_list); spin_unlock_bh(&conn->session->lock); - if (tt->xmit_mgmt_task(conn, conn->mtask)) + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) goto again; } /* done with this mtask */ conn->mtask = NULL; } - return 0; + return -ENODATA; again: if (unlikely(conn->suspend_tx)) - return 0; + return -ENODATA; - return -EAGAIN; + return rc; } static void iscsi_xmitworker(void *data) { struct iscsi_conn *conn = data; - + int rc; /* * serialize Xmit worker on a per-connection basis. */ mutex_lock(&conn->xmitmutex); - if (iscsi_data_xmit(conn)) - scsi_queue_work(conn->session->host, &conn->xmitwork); + do { + rc = iscsi_data_xmit(conn); + } while (rc >= 0 || rc == -EAGAIN); mutex_unlock(&conn->xmitmutex); } |