Commit f161d4b4 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Fix PR_APTPL_BUF_LEN buffer size limitation 



This patch addresses the original PR_APTPL_BUF_LEN = 8k limitiation
for write-out of PR APTPL metadata that Martin has recently been
running into.

It changes core_scsi3_update_and_write_aptpl() to use vzalloc'ed
memory instead of kzalloc, and increases the default hardcoded
length to 256k.

It also adds logic in core_scsi3_update_and_write_aptpl() to double
the original length upon core_scsi3_update_aptpl_buf() failure, and
retries until the vzalloc'ed buffer is large enough to accommodate
the outgoing APTPL metadata.

Reported-by: default avatarMartin Svec <martin.svec@zoner.cz>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 3fd7b60f

drivers/target/target_core_pr.c

+13 −12
Original line number Diff line number Diff line
@@ -1862,8 +1862,8 @@ static int core_scsi3_update_aptpl_buf( 
		}



		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {

			pr_err("Unable to update renaming"

				" APTPL metadata\n");

			pr_err("Unable to update renaming APTPL metadata,"

			       " reallocating larger buffer\n");

			ret = -EMSGSIZE;

			goto out;

		}
@@ -1880,8 +1880,8 @@ static int core_scsi3_update_aptpl_buf( 
			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);



		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {

			pr_err("Unable to update renaming"

				" APTPL metadata\n");

			pr_err("Unable to update renaming APTPL metadata,"

			       " reallocating larger buffer\n");

			ret = -EMSGSIZE;

			goto out;

		}
@@ -1944,7 +1944,7 @@ static int __core_scsi3_write_aptpl_to_file( 
static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)

{

	unsigned char *buf;

	int rc;

	int rc, len = PR_APTPL_BUF_LEN;



	if (!aptpl) {

		char *null_buf = "No Registrations or Reservations\n";
@@ -1958,25 +1958,26 @@ static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, b 


		return 0;

	}



	buf = kzalloc(PR_APTPL_BUF_LEN, GFP_KERNEL);

retry:

	buf = vzalloc(len);

	if (!buf)

		return TCM_OUT_OF_RESOURCES;



	rc = core_scsi3_update_aptpl_buf(dev, buf, PR_APTPL_BUF_LEN);

	rc = core_scsi3_update_aptpl_buf(dev, buf, len);

	if (rc < 0) {

		kfree(buf);

		return TCM_OUT_OF_RESOURCES;

		vfree(buf);

		len *= 2;

		goto retry;

	}



	rc = __core_scsi3_write_aptpl_to_file(dev, buf);

	if (rc != 0) {

		pr_err("SPC-3 PR: Could not update APTPL\n");

		kfree(buf);

		vfree(buf);

		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	}

	dev->t10_pr.pr_aptpl_active = 1;

	kfree(buf);

	vfree(buf);

	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");

	return 0;

}

include/target/target_core_base.h

+1 −1
Original line number Diff line number Diff line
@@ -409,7 +409,7 @@ struct t10_reservation { 
	/* Activate Persistence across Target Power Loss enabled

	 * for SCSI device */

	int pr_aptpl_active;

#define PR_APTPL_BUF_LEN			8192

#define PR_APTPL_BUF_LEN			262144

	u32 pr_generation;

	spinlock_t registration_lock;

	spinlock_t aptpl_reg_lock;

CRA Git | Maintained and supported by SUSTech CRA and CCSE