Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-13 07:31:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

scsi: scsi_debug: Don't iter all shosts in clear_luns_changed_on_target()

Browse Source 
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>
Link: https://lore.kernel.org/r/20230327074310.1862889-3-john.g.garry@oracle.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
John Garry 2023-03-27 07:43:01 +00:00 committed by Martin K. Petersen
parent 6500d2045d
commit 00f9d622e8
1 changed files with 5 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/scsi/scsi_debug.c
View File

@ -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)