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[PATCH] libata: locking rewrite (== fix) 

[libata] locking rewrite (== fix)

A lot of power packed into a little patch.

This change eliminates the sharing between our controller-wide spinlock
and the SCSI core's Scsi_Host lock.  As the locking in libata was
already highly compartmentalized, always referencing our own lock, and
never scsi_host::host_lock.

As a side effect, this change eliminates a deadlock from calling
scsi_finish_command() while inside our spinlock.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jeff Garzik 2005-10-31 09:05:36 -08:00 committed by Greg Kroah-Hartman
parent 51adb32b28
commit d7283d6130
2 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/scsi/libata-core.c
View File

@ -3916,8 +3916,6 @@ static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host,
host->unique_id = ata_unique_id++;
host->max_cmd_len = 12;
scsi_assign_lock(host, &host_set->lock);
ap->flags = ATA_FLAG_PORT_DISABLED;
ap->id = host->unique_id;
ap->host = host;

9
drivers/scsi/libata-scsi.c
View File

@ -39,6 +39,7 @@
#include <scsi/scsi.h>
#include "scsi.h"
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <linux/libata.h>
#include <asm/uaccess.h>
@ -1565,8 +1566,12 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
struct ata_port *ap;
struct ata_device *dev;
struct scsi_device *scsidev = cmd->device;
struct Scsi_Host *shost = scsidev->host;
ap = (struct ata_port *) &scsidev->host->hostdata[0];
ap = (struct ata_port *) &shost->hostdata[0];
spin_unlock(shost->host_lock);
spin_lock(&ap->host_set->lock);
ata_scsi_dump_cdb(ap, cmd);
@ -1589,6 +1594,8 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
ata_scsi_translate(ap, dev, cmd, done, atapi_xlat);
out_unlock:
spin_unlock(&ap->host_set->lock);
spin_lock(shost->host_lock);
return 0;
}