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- Eliminate theorethically possible race leading to sending wrong max_sn to initiators

Browse Source 
- Alignment cleanups



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@2022 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Vladislav Bolkhovitin
2010-08-30 20:34:17 +00:00
parent 94d701bdfa
commit 3120885a46
2 changed files with 49 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files
iscsi-scst/kernel/iscsi.c
+37 -31
View File
@@ -343,6 +343,29 @@ static void cmnd_free(struct iscsi_cmnd *cmnd)
return;
}
static void iscsi_dec_active_cmds(struct iscsi_cmnd *req)
{
struct iscsi_session *sess = req->conn->session;
TRACE_DBG("Decrementing active_cmds (req %p, sess %p, "
"new value %d)", req, sess,
atomic_read(&sess->active_cmds)-1);
EXTRACHECKS_BUG_ON(!req->dec_active_cmds);
atomic_dec(&sess->active_cmds);
smp_mb__after_atomic_dec();
req->dec_active_cmds = 0;
#ifdef CONFIG_SCST_EXTRACHECKS
if (unlikely(atomic_read(&sess->active_cmds) < 0)) {
PRINT_CRIT_ERROR("active_cmds < 0 (%d)!!",
atomic_read(&sess->active_cmds));
sBUG();
}
#endif
return;
}
/* Might be called under some lock and on SIRQ */
void cmnd_done(struct iscsi_cmnd *cmnd)
{
@@ -425,20 +448,8 @@ void cmnd_done(struct iscsi_cmnd *cmnd)
#endif
}
if (cmnd->dec_active_cmnds) {
struct iscsi_session *sess = cmnd->conn->session;
TRACE_DBG("Decrementing active_cmds (cmd %p, sess %p, "
"new value %d)", cmnd, sess,
atomic_read(&sess->active_cmds)-1);
atomic_dec(&sess->active_cmds);
#ifdef CONFIG_SCST_EXTRACHECKS
if (unlikely(atomic_read(&sess->active_cmds) < 0)) {
PRINT_CRIT_ERROR("active_cmds < 0 (%d)!!",
atomic_read(&sess->active_cmds));
sBUG();
}
#endif
}
if (unlikely(cmnd->dec_active_cmds))
iscsi_dec_active_cmds(cmnd);
list_for_each_entry_safe(rsp, t, &cmnd->rsp_cmd_list,
rsp_cmd_list_entry) {
@@ -460,7 +471,7 @@ void cmnd_done(struct iscsi_cmnd *cmnd)
#endif
}
EXTRACHECKS_BUG_ON(cmnd->dec_active_cmnds);
EXTRACHECKS_BUG_ON(cmnd->dec_active_cmds);
if (cmnd == parent->main_rsp) {
TRACE_DBG("Finishing main rsp %p (req %p)", cmnd,
@@ -601,21 +612,8 @@ static void req_cmnd_pre_release(struct iscsi_cmnd *req)
EXTRACHECKS_BUG_ON(req->pending);
if (req->dec_active_cmnds) {
struct iscsi_session *sess = req->conn->session;
TRACE_DBG("Decrementing active_cmds (cmd %p, sess %p, "
"new value %d)", req, sess,
atomic_read(&sess->active_cmds)-1);
atomic_dec(&sess->active_cmds);
req->dec_active_cmnds = 0;
#ifdef CONFIG_SCST_EXTRACHECKS
if (unlikely(atomic_read(&sess->active_cmds) < 0)) {
PRINT_CRIT_ERROR("active_cmds < 0 (%d)!!",
atomic_read(&sess->active_cmds));
sBUG();
}
#endif
}
if (unlikely(req->dec_active_cmds))
iscsi_dec_active_cmds(req);
TRACE_EXIT();
return;
@@ -1901,7 +1899,7 @@ static int scsi_cmnd_start(struct iscsi_cmnd *req)
"new value %d)", req, session,
atomic_read(&session->active_cmds)+1);
atomic_inc(&session->active_cmds);
req->dec_active_cmnds = 1;
req->dec_active_cmds = 1;
scst_cmd = scst_rx_cmd(session->scst_sess,
(uint8_t *)&req_hdr->lun, sizeof(req_hdr->lun),
@@ -3280,6 +3278,14 @@ static int iscsi_xmit_response(struct scst_cmd *scst_cmd)
sBUG(); /* ToDo */
}
/*
* We need to decrement active_cmds before adding any responses into
* the write queue to eliminate a race, when all responses sent
* with wrong MaxCmdSN.
*/
if (likely(req->dec_active_cmds))
iscsi_dec_active_cmds(req);
if (req->bufflen != 0) {
/*
* Check above makes sure that is_send_status is set,
iscsi-scst/kernel/iscsi.h
+12 -5
View File
@@ -173,7 +173,7 @@ struct iscsi_conn {
#define ISCSI_CONN_REINSTATING 1
#define ISCSI_CONN_SHUTTINGDOWN 2
unsigned long conn_aflags __attribute__((aligned(sizeof(long))));
unsigned long conn_aflags;
spinlock_t cmd_list_lock; /* BH lock */
@@ -192,7 +192,10 @@ struct iscsi_conn {
struct timer_list rsp_timer;
unsigned int rsp_timeout; /* in jiffies */
/* All 2 protected by iscsi_wr_lock */
/*
* All 2 protected by iscsi_wr_lock. Modified independently to the
* above field, hence the alignment.
*/
unsigned short wr_state __attribute__((aligned(sizeof(long))));
unsigned short wr_space_ready:1;
@@ -344,7 +347,7 @@ struct iscsi_cmnd {
unsigned int on_write_list:1;
unsigned int write_processing_started:1;
unsigned int force_cleanup_done:1;
unsigned int dec_active_cmnds:1;
unsigned int dec_active_cmds:1;
unsigned int ddigest_checked:1;
#ifdef CONFIG_SCST_EXTRACHECKS
unsigned int on_rx_digest_list:1;
@@ -361,7 +364,7 @@ struct iscsi_cmnd {
*/
#define ISCSI_CMD_ABORTED 0
#define ISCSI_CMD_PRELIM_COMPLETED 1
unsigned long prelim_compl_flags __attribute__((aligned(sizeof(long))));
unsigned long prelim_compl_flags;
struct list_head hash_list_entry;
@@ -421,7 +424,11 @@ struct iscsi_cmnd {
struct iscsi_cmnd *main_rsp;
/* Protected on modify by conn->write_list_lock */
/*
* Protected on modify by conn->write_list_lock, hence
* modified independently to the above field, hence the
* alignment.
*/
int not_processed_rsp_cnt
__attribute__((aligned(sizeof(long))));
};