mirrors/scst
1
0
Fork 0
mirror of https://github.com/SCST-project/scst.git synced 2026-05-29 09:50:19 +00:00
Code Issues Packages Projects Releases Wiki Activity

Few minor races fixed

Browse Source 
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@148 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Vladislav Bolkhovitin
2007-07-13 09:34:25 +00:00
parent e37c03bbd7
commit 4a44c43a61
4 changed files with 46 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
scst/include/scsi_tgt.h
View File

@@ -420,16 +420,6 @@ struct scst_tgt_template
/* True, if the template doesn't need the entry in /proc */
unsigned no_proc_entry:1;
/*
* True, if the target requires that *ALL* affecting by a task
* management command outstanding SCSI commands finished before
* sending the TM command reply. Otherwise, the TM reply will be
* send immediately after it is insured, that the affecting SCSI
* commands will reach xmit_response() with ABORTED flag set (see
* also scst_cmd_aborted()).
*/
unsigned tm_sync_reply:1;
/*
* This function is equivalent to the SCSI
* queuecommand. The target should transmit the response
@@ -853,8 +843,8 @@ struct scst_session
/* Used for storage of target driver private stuff */
void *tgt_priv;
/* Alive commands for this session, protected by sess_list_lock */
int sess_cmd_count;
/* Alive commands for this session. ToDo: make it part of common IO flow control */
atomic_t sess_cmd_count;
spinlock_t sess_list_lock; /* protects search_cmd_list, etc */

4
scst/src/scst_lib.c
View File

@@ -86,7 +86,7 @@ void scst_set_cmd_error_sense(struct scst_cmd *cmd, uint8_t *sense,
void scst_set_busy(struct scst_cmd *cmd)
{
int c = cmd->sess->sess_cmd_count;
int c = atomic_read(&cmd->sess->sess_cmd_count);
TRACE_ENTRY();
@@ -1371,7 +1371,7 @@ void scst_free_mgmt_cmd(struct scst_mgmt_cmd *mcmd)
TRACE_ENTRY();
spin_lock_irqsave(&mcmd->sess->sess_list_lock, flags);
mcmd->sess->sess_cmd_count--;
atomic_dec(&mcmd->sess->sess_cmd_count);
spin_unlock_irqrestore(&mcmd->sess->sess_list_lock, flags);
scst_sess_put(mcmd->sess);

2
scst/src/scst_proc.c
View File

@@ -1703,7 +1703,7 @@ static int scst_sessions_info_show(struct seq_file *seq, void *v)
sess->tgt->tgtt->name,
sess->initiator_name,
acg->acg_name,
sess->sess_cmd_count);
atomic_read(&sess->sess_cmd_count));
}
}

85
scst/src/scst_targ.c
View File

@@ -181,9 +181,10 @@ void scst_cmd_init_done(struct scst_cmd *cmd, int pref_context)
}
#endif
atomic_inc(&sess->sess_cmd_count);
spin_lock_irqsave(&sess->sess_list_lock, flags);
sess->sess_cmd_count++;
list_add_tail(&cmd->search_cmd_list_entry, &sess->search_cmd_list);
if (unlikely(sess->init_phase != SCST_SESS_IPH_READY)) {
@@ -2312,6 +2313,17 @@ static int scst_xmit_response(struct scst_cmd *cmd)
goto out;
}
/*
* If we don't remove cmd from the search list here, before
* submitting it for transmittion, we will have a race, when for
* some reason cmd's release is delayed after transmittion and
* initiator sends cmd with the same tag => it is possible that
* a wrong cmd will be found by find() functions.
*/
spin_lock_irq(&cmd->sess->sess_list_lock);
list_del(&cmd->search_cmd_list_entry);
spin_unlock_irq(&cmd->sess->sess_list_lock);
set_bit(SCST_CMD_XMITTING, &cmd->cmd_flags);
smp_mb__after_set_bit();
@@ -2449,10 +2461,7 @@ static int scst_finish_cmd(struct scst_cmd *cmd)
spin_unlock_bh(&scst_cmd_mem_lock);
}
spin_lock_irq(&cmd->sess->sess_list_lock);
cmd->sess->sess_cmd_count--;
list_del(&cmd->search_cmd_list_entry);
spin_unlock_irq(&cmd->sess->sess_list_lock);
atomic_dec(&cmd->sess->sess_cmd_count);
if (unlikely(test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))) {
TRACE_MGMT_DBG("Aborted cmd %p finished (cmd_ref %d, "
@@ -3143,44 +3152,32 @@ void scst_abort_cmd(struct scst_cmd *cmd, struct scst_mgmt_cmd *mcmd,
}
if (mcmd) {
int defer;
if (cmd->tgtt->tm_sync_reply)
defer = 1;
else {
if (scst_is_strict_mgmt_fn(mcmd->fn))
defer = test_bit(SCST_CMD_EXECUTING,
&cmd->cmd_flags);
else
defer = test_bit(SCST_CMD_XMITTING,
&cmd->cmd_flags);
}
if (defer) {
unsigned long flags;
/*
* Delay the response until the command's finish in
* order to guarantee that "no further responses from
* the task are sent to the SCSI initiator port" after
* response from the TM function is sent (SAM)
*/
TRACE(TRACE_MGMT, "cmd %p (tag %d) being executed/"
"xmitted (state %d), deferring ABORT...", cmd,
cmd->tag, cmd->state);
unsigned long flags;
/*
* Delay the response until the command's finish in
* order to guarantee that "no further responses from
* the task are sent to the SCSI initiator port" after
* response from the TM function is sent (SAM). Plus,
* we must wait here to be sure that we won't receive
* double commands with the same tag.
*/
TRACE(TRACE_MGMT, "cmd %p (tag %d) being executed/"
"xmitted (state %d), deferring ABORT...", cmd,
cmd->tag, cmd->state);
#ifdef EXTRACHECKS
if (cmd->mgmt_cmnd) {
printk(KERN_ALERT "cmd %p (tag %d, state %d) "
"has non-NULL mgmt_cmnd %p!!! Current "
"mcmd %p\n", cmd, cmd->tag, cmd->state,
cmd->mgmt_cmnd, mcmd);
}
#endif
sBUG_ON(cmd->mgmt_cmnd);
spin_lock_irqsave(&scst_mcmd_lock, flags);
mcmd->cmd_wait_count++;
spin_unlock_irqrestore(&scst_mcmd_lock, flags);
/* cmd can't die here or sess_list_lock already taken */
cmd->mgmt_cmnd = mcmd;
if (cmd->mgmt_cmnd) {
printk(KERN_ALERT "cmd %p (tag %d, state %d) "
"has non-NULL mgmt_cmnd %p!!! Current "
"mcmd %p\n", cmd, cmd->tag, cmd->state,
cmd->mgmt_cmnd, mcmd);
}
#endif
sBUG_ON(cmd->mgmt_cmnd);
spin_lock_irqsave(&scst_mcmd_lock, flags);
mcmd->cmd_wait_count++;
spin_unlock_irqrestore(&scst_mcmd_lock, flags);
/* cmd can't die here or sess_list_lock already taken */
cmd->mgmt_cmnd = mcmd;
}
tm_dbg_release_cmd(cmd);
@@ -3407,7 +3404,7 @@ static int scst_target_reset(struct scst_mgmt_cmd *mcmd)
TRACE_ENTRY();
TRACE(TRACE_MGMT, "Target reset (mcmd %p, cmd count %d)",
mcmd, mcmd->sess->sess_cmd_count);
mcmd, atomic_read(&mcmd->sess->sess_cmd_count));
down(&scst_mutex);
@@ -3927,7 +3924,7 @@ static int scst_post_rx_mgmt_cmd(struct scst_session *sess,
local_irq_save(flags);
spin_lock(&sess->sess_list_lock);
sess->sess_cmd_count++;
atomic_inc(&sess->sess_cmd_count);
#ifdef EXTRACHECKS
if (unlikely(sess->shutting_down)) {
@@ -4172,7 +4169,7 @@ restart:
cmd_list_entry) {
TRACE_DBG("Deleting cmd %p from init deferred cmd list", cmd);
list_del(&cmd->cmd_list_entry);
sess->sess_cmd_count--;
atomic_dec(&sess->sess_cmd_count);
list_del(&cmd->search_cmd_list_entry);
spin_unlock_irq(&sess->sess_list_lock);
scst_cmd_init_done(cmd, SCST_CONTEXT_THREAD);