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Commit 315cb0ad authored by James Smart's avatar James Smart Committed by James Bottomley
Browse files

[SCSI] scsi_host_lookup: error returns and NULL pointers 



This patch cleans up the behavior of scsi_host_lookup().

The original implementation attempted to use the dual role of
either returning a pointer value, or a negative error code.
User's needed to use IS_ERR() to check the result. Additionally,
the IS_ERR() macro never checks for when a NULL pointer was
returned, so a NULL pointer actually passes with a success case.
Note: scsi_host_get(), used by scsi_host_lookup(), can return
a NULL pointer.

Talk about a mudhole for the unitiated to step into....

This patch converts scsi_host_lookup() to return either NULL
or a valid pointer. The consumers were updated for the change.

Signed-off-by: default avatarJames Smart <james.smart@emulex.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 6f92a6a7

drivers/scsi/hosts.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -464,7 +464,7 @@ static int __scsi_host_match(struct device *dev, void *data) 
struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)

struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)

{

{

	struct device *cdev;

	struct device *cdev;

	struct Scsi_Host *shost = ERR_PTR(-ENXIO);

	struct Scsi_Host *shost = NULL;





	cdev = class_find_device(&shost_class, NULL, &hostnum,

	cdev = class_find_device(&shost_class, NULL, &hostnum,

				 __scsi_host_match);

				 __scsi_host_match);

drivers/scsi/scsi_proc.c

+4 −4
Original line number Original line Diff line number Diff line
@@ -259,8 +259,8 @@ static int scsi_add_single_device(uint host, uint channel, uint id, uint lun) 
	int error = -ENXIO;

	int error = -ENXIO;





	shost = scsi_host_lookup(host);

	shost = scsi_host_lookup(host);

	if (IS_ERR(shost))

	if (!shost)

		return PTR_ERR(shost);

		return error;





	if (shost->transportt->user_scan)

	if (shost->transportt->user_scan)

		error = shost->transportt->user_scan(shost, channel, id, lun);

		error = shost->transportt->user_scan(shost, channel, id, lun);
@@ -287,8 +287,8 @@ static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun) 
	int error = -ENXIO;

	int error = -ENXIO;





	shost = scsi_host_lookup(host);

	shost = scsi_host_lookup(host);

	if (IS_ERR(shost))

	if (!shost)

		return PTR_ERR(shost);

		return error;

	sdev = scsi_device_lookup(shost, channel, id, lun);

	sdev = scsi_device_lookup(shost, channel, id, lun);

	if (sdev) {

	if (sdev) {

		scsi_remove_device(sdev);

		scsi_remove_device(sdev);

drivers/scsi/scsi_tgt_lib.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -460,7 +460,7 @@ int scsi_tgt_kspace_exec(int host_no, u64 itn_id, int result, u64 tag, 




	/* TODO: replace with a O(1) alg */

	/* TODO: replace with a O(1) alg */

	shost = scsi_host_lookup(host_no);

	shost = scsi_host_lookup(host_no);

	if (IS_ERR(shost)) {

	if (!shost) {

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		return -EINVAL;

		return -EINVAL;

	}

	}
@@ -550,7 +550,7 @@ int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 itn_id, u64 mid, int result) 
	dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);

	dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);





	shost = scsi_host_lookup(host_no);

	shost = scsi_host_lookup(host_no);

	if (IS_ERR(shost)) {

	if (!shost) {

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		return err;

		return err;

	}

	}
@@ -603,7 +603,7 @@ int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result) 
	dprintk("%d %d%llx\n", host_no, result, (unsigned long long)itn_id);

	dprintk("%d %d%llx\n", host_no, result, (unsigned long long)itn_id);





	shost = scsi_host_lookup(host_no);

	shost = scsi_host_lookup(host_no);

	if (IS_ERR(shost)) {

	if (!shost) {

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		return err;

		return err;

	}

	}

drivers/scsi/scsi_transport_iscsi.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -1361,7 +1361,7 @@ iscsi_tgt_dscvr(struct iscsi_transport *transport, 
		return -EINVAL;

		return -EINVAL;





	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);

	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);

	if (IS_ERR(shost)) {

	if (!shost) {

		printk(KERN_ERR "target discovery could not find host no %u\n",

		printk(KERN_ERR "target discovery could not find host no %u\n",

		       ev->u.tgt_dscvr.host_no);

		       ev->u.tgt_dscvr.host_no);

		return -ENODEV;

		return -ENODEV;
@@ -1387,7 +1387,7 @@ iscsi_set_host_param(struct iscsi_transport *transport, 
		return -ENOSYS;

		return -ENOSYS;





	shost = scsi_host_lookup(ev->u.set_host_param.host_no);

	shost = scsi_host_lookup(ev->u.set_host_param.host_no);

	if (IS_ERR(shost)) {

	if (!shost) {

		printk(KERN_ERR "set_host_param could not find host no %u\n",

		printk(KERN_ERR "set_host_param could not find host no %u\n",

		       ev->u.set_host_param.host_no);

		       ev->u.set_host_param.host_no);

		return -ENODEV;

		return -ENODEV;