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[SCSI] sd: update index allocation and use ida instead of idr

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Update index allocation as follows.

* sd_index_idr is used only for ID allocation and mapping
  functionality is not used.  Use more memory efficient ida instead.

* idr and ida have their own locks inside them and don't need them for
  operation.  Drop it.

* index wasn't freed if probing failed after index allocation.  fix
  it.

* ida allocation should be repeated if it fails with -EAGAIN.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Tejun Heo 2008-07-14 14:59:30 +09:00 committed by James Bottomley
parent ecefe8a975
commit f27bac2761
1 changed files with 14 additions and 13 deletions
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27
drivers/scsi/sd.c
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@ -99,8 +99,7 @@ static void scsi_disk_release(struct device *cdev);
static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
static void sd_print_result(struct scsi_disk *, int);
static DEFINE_IDR(sd_index_idr);
static DEFINE_SPINLOCK(sd_index_lock);
static DEFINE_IDA(sd_index_ida);
/* This semaphore is used to mediate the 0->1 reference get in the
* face of object destruction (i.e. we can't allow a get on an
@ -1643,18 +1642,20 @@ static int sd_probe(struct device *dev)
if (!gd)
goto out_free;
if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
goto out_put;
do {
if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
goto out_put;
spin_lock(&sd_index_lock);
error = idr_get_new(&sd_index_idr, NULL, &index);
spin_unlock(&sd_index_lock);
error = ida_get_new(&sd_index_ida, &index);
} while (error == -EAGAIN);
if (index >= SD_MAX_DISKS)
error = -EBUSY;
if (error)
goto out_put;
error = -EBUSY;
if (index >= SD_MAX_DISKS)
goto out_free_index;
sdkp->device = sdp;
sdkp->driver = &sd_template;
sdkp->disk = gd;
@ -1675,7 +1676,7 @@ static int sd_probe(struct device *dev)
strncpy(sdkp->dev.bus_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE);
if (device_add(&sdkp->dev))
goto out_put;
goto out_free_index;
get_device(&sdp->sdev_gendev);
@ -1717,6 +1718,8 @@ static int sd_probe(struct device *dev)
return 0;
out_free_index:
ida_remove(&sd_index_ida, index);
out_put:
put_disk(gd);
out_free:
@ -1766,9 +1769,7 @@ static void scsi_disk_release(struct device *dev)
struct scsi_disk *sdkp = to_scsi_disk(dev);
struct gendisk *disk = sdkp->disk;
spin_lock(&sd_index_lock);
idr_remove(&sd_index_idr, sdkp->index);
spin_unlock(&sd_index_lock);
ida_remove(&sd_index_ida, sdkp->index);
disk->private_data = NULL;
put_disk(disk);