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@xxxxxxxxxx>
---
This patch will be depended on by later block layer updates. If the
block layer changes get acked. I think it'll be best to route this
patch through blk tree. Thanks.
drivers/scsi/sd.c | 27 ++++++++++++++-------------
1 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 01cefbb..c330f16 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -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
@@ -1646,18 +1645,20 @@ 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;
@@ -1678,7 +1679,7 @@ 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);
@@ -1720,6 +1721,8 @@ 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:
@@ -1769,9 +1772,7 @@ 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);
--
1.5.4.5
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