From d01712698c7c52bc71f41192e864dccc90a1217d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 12 Jun 2006 22:51:14 +0900 Subject: [PATCH] libata: fix oops caused rescanning NULL sdev Depending on timing, ata_scsi_dev_rescan() might encounter a device which is enabled but not yet attached to sdev. On such cases, the original code caused oops. This patch makes ata_scsi_dev_rescan() rescan only device which are attached to sdevs. While at it, properly indent leading comment and add description about how it's synchronized with sdev attach/detach. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- drivers/scsi/libata-scsi.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c index 45a49be6504..32c1df69091 100644 --- a/drivers/scsi/libata-scsi.c +++ b/drivers/scsi/libata-scsi.c @@ -3005,14 +3005,16 @@ static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel, } /** - * ata_scsi_dev_rescan - initiate scsi_rescan_device() - * @data: Pointer to ATA port to perform scsi_rescan_device() + * ata_scsi_dev_rescan - initiate scsi_rescan_device() + * @data: Pointer to ATA port to perform scsi_rescan_device() * - * After ATA pass thru (SAT) commands are executed successfully, - * libata need to propagate the changes to SCSI layer. + * After ATA pass thru (SAT) commands are executed successfully, + * libata need to propagate the changes to SCSI layer. This + * function must be executed from ata_aux_wq such that sdev + * attach/detach don't race with rescan. * - * LOCKING: - * Kernel thread context (may sleep). + * LOCKING: + * Kernel thread context (may sleep). */ void ata_scsi_dev_rescan(void *data) { @@ -3023,8 +3025,7 @@ void ata_scsi_dev_rescan(void *data) for (i = 0; i < ATA_MAX_DEVICES; i++) { dev = &ap->device[i]; - if (ata_dev_enabled(dev)) + if (ata_dev_enabled(dev) && dev->sdev) scsi_rescan_device(&(dev->sdev->sdev_gendev)); } } - -- cgit v1.2.3