| Message ID | 20230327074310.1862889-3-john.g.garry@oracle.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Fix shost command overloading issues | expand |
On 2023-03-27 03:43, John Garry wrote: > In clear_luns_changed_on_target(), we iter all devices for all shosts to > conditionally clear the SDEBUG_UA_LUNS_CHANGED flag in the per-device > uas_bm. > > One condition to see whether we clear the flag is to test whether the host > for the device under consideration is the same as the matching device's > (devip) host. This check will only ever pass for devices for the same > shost, so only iter the devices for the matching device shost. > > We can now drop the spinlock'ing of the sdebug_host_list_lock in the same > function. This will allow us to use a mutex instead of the spinlock for > the global shost lock, as clear_luns_changed_on_target() could be called > in non-blocking context, in scsi_debug_queuecommand() -> make_ua() -> > clear_luns_changed_on_target() (which is why required a spinlock). > > Signed-off-by: John Garry <john.g.garry@oracle.com> Acked-by: Douglas Gilbert <dgilbert@interlog.com Thanks. > --- > drivers/scsi/scsi_debug.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c > index 782515abca2c..eba6eca81e84 100644 > --- a/drivers/scsi/scsi_debug.c > +++ b/drivers/scsi/scsi_debug.c > @@ -1063,18 +1063,15 @@ static void all_config_cdb_len(void) > > static void clear_luns_changed_on_target(struct sdebug_dev_info *devip) > { > - struct sdebug_host_info *sdhp; > + struct sdebug_host_info *sdhp = devip->sdbg_host; > struct sdebug_dev_info *dp; > > - spin_lock(&sdebug_host_list_lock); > - list_for_each_entry(sdhp, &sdebug_host_list, host_list) { > - list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) { > - if ((devip->sdbg_host == dp->sdbg_host) && > - (devip->target == dp->target)) > - clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm); > + list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) { > + if ((devip->sdbg_host == dp->sdbg_host) && > + (devip->target == dp->target)) { > + clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm); > } > } > - spin_unlock(&sdebug_host_list_lock); > } > > static int make_ua(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 782515abca2c..eba6eca81e84 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1063,18 +1063,15 @@ static void all_config_cdb_len(void) static void clear_luns_changed_on_target(struct sdebug_dev_info *devip) { - struct sdebug_host_info *sdhp; + struct sdebug_host_info *sdhp = devip->sdbg_host; struct sdebug_dev_info *dp; - spin_lock(&sdebug_host_list_lock); - list_for_each_entry(sdhp, &sdebug_host_list, host_list) { - list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) { - if ((devip->sdbg_host == dp->sdbg_host) && - (devip->target == dp->target)) - clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm); + list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) { + if ((devip->sdbg_host == dp->sdbg_host) && + (devip->target == dp->target)) { + clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm); } } - spin_unlock(&sdebug_host_list_lock); } static int make_ua(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
In clear_luns_changed_on_target(), we iter all devices for all shosts to conditionally clear the SDEBUG_UA_LUNS_CHANGED flag in the per-device uas_bm. One condition to see whether we clear the flag is to test whether the host for the device under consideration is the same as the matching device's (devip) host. This check will only ever pass for devices for the same shost, so only iter the devices for the matching device shost. We can now drop the spinlock'ing of the sdebug_host_list_lock in the same function. This will allow us to use a mutex instead of the spinlock for the global shost lock, as clear_luns_changed_on_target() could be called in non-blocking context, in scsi_debug_queuecommand() -> make_ua() -> clear_luns_changed_on_target() (which is why required a spinlock). Signed-off-by: John Garry <john.g.garry@oracle.com> --- drivers/scsi/scsi_debug.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)