Commit fe635c7e authored by Tejun Heo's avatar Tejun Heo
Browse files

[PATCH] libata: use preallocated buffers 



It's not a very good idea to allocate memory during EH.  Use
statically allocated buffer for dev->id[] and add 512byte buffer
ap->sector_buf.  This buffer is owned by EH (or probing) and to be
used as temporary buffer for various purposes (IDENTIFY, NCQ log page
10h, PM GSCR block).

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
parent 15869303

drivers/scsi/libata-core.c

+8 −24
Original line number Diff line number Diff line
@@ -1099,7 +1099,7 @@ unsigned int ata_pio_need_iordy(const struct ata_device *adev) 
 *	@dev: target device

 *	@p_class: pointer to class of the target device (may be changed)

 *	@post_reset: is this read ID post-reset?

 *	@p_id: read IDENTIFY page (newly allocated)

 *	@id: buffer to read IDENTIFY data into

 *

 *	Read ID data from the specified device.  ATA_CMD_ID_ATA is

 *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
@@ -1113,12 +1113,11 @@ unsigned int ata_pio_need_iordy(const struct ata_device *adev) 
 *	0 on success, -errno otherwise.

 */

static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev,

			   unsigned int *p_class, int post_reset, u16 **p_id)

			   unsigned int *p_class, int post_reset, u16 *id)

{

	unsigned int class = *p_class;

	struct ata_taskfile tf;

	unsigned int err_mask = 0;

	u16 *id;

	const char *reason;

	int rc;
@@ -1126,13 +1125,6 @@ static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev, 


	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */



	id = kmalloc(sizeof(id[0]) * ATA_ID_WORDS, GFP_KERNEL);

	if (id == NULL) {

		rc = -ENOMEM;

		reason = "out of memory";

		goto err_out;

	}



 retry:

	ata_tf_init(ap, &tf, dev->devno);
@@ -1194,13 +1186,12 @@ static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev, 
	}



	*p_class = class;

	*p_id = id;



	return 0;



 err_out:

	printk(KERN_WARNING "ata%u: dev %u failed to IDENTIFY (%s)\n",

	       ap->id, dev->devno, reason);

	kfree(id);

	return rc;

}
@@ -1425,9 +1416,7 @@ static int ata_bus_probe(struct ata_port *ap) 
		if (!ata_dev_enabled(dev))

			continue;



		kfree(dev->id);

		dev->id = NULL;

		rc = ata_dev_read_id(ap, dev, &dev->class, 1, &dev->id);

		rc = ata_dev_read_id(ap, dev, &dev->class, 1, dev->id);

		if (rc)

			goto fail;
@@ -2788,7 +2777,7 @@ int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev, 
		       int post_reset)

{

	unsigned int class = dev->class;

	u16 *id = NULL;

	u16 *id = (void *)ap->sector_buf;

	int rc;



	if (!ata_dev_enabled(dev)) {
@@ -2796,8 +2785,8 @@ int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev, 
		goto fail;

	}



	/* allocate & read ID data */

	rc = ata_dev_read_id(ap, dev, &class, post_reset, &id);

	/* read ID data */

	rc = ata_dev_read_id(ap, dev, &class, post_reset, id);

	if (rc)

		goto fail;
@@ -2807,8 +2796,7 @@ int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev, 
		goto fail;

	}



	kfree(dev->id);

	dev->id = id;

	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);



	/* configure device according to the new ID */

	rc = ata_dev_configure(ap, dev, 0);
@@ -2818,7 +2806,6 @@ int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev, 
 fail:

	printk(KERN_ERR "ata%u: dev %u revalidation failed (errno=%d)\n",

	       ap->id, dev->devno, rc);

	kfree(id);

	return rc;

}
@@ -4873,14 +4860,11 @@ void ata_host_set_remove(struct ata_host_set *host_set) 
int ata_scsi_release(struct Scsi_Host *host)

{

	struct ata_port *ap = ata_shost_to_port(host);

	int i;



	DPRINTK("ENTER\n");



	ap->ops->port_disable(ap);

	ata_host_remove(ap, 0);

	for (i = 0; i < ATA_MAX_DEVICES; i++)

		kfree(ap->device[i].id);



	DPRINTK("EXIT\n");

	return 1;

include/linux/libata.h

+3 −1
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ struct ata_device { 
	unsigned long		flags;		/* ATA_DFLAG_xxx */

	unsigned int		class;		/* ATA_DEV_xxx */

	unsigned int		devno;		/* 0 or 1 */

	u16			*id;		/* IDENTIFY xxx DEVICE data */

	u16			id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */

	u8			pio_mode;

	u8			dma_mode;

	u8			xfer_mode;
@@ -425,6 +425,8 @@ struct ata_port { 
	struct list_head	eh_done_q;



	void			*private_data;



	u8			sector_buf[ATA_SECT_SIZE]; /* owned by EH */

};



struct ata_port_operations {