From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Svec , Nicholas Bellinger Subject: [PATCH 3.14 28/96] target: Fix PR_APTPL_BUF_LEN buffer size limitation Date: Mon, 16 Mar 2015 15:08:59 +0100 Message-Id: <20150316140856.469801644@linuxfoundation.org> In-Reply-To: <20150316140855.186617380@linuxfoundation.org> References: <20150316140855.186617380@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit f161d4b44d7cc1dc66b53365215227db356378b1 upstream. 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: Martin Svec Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_pr.c | 25 +++++++++++++------------ include/target/target_core_base.h | 2 +- 2 files changed, 14 insertions(+), 13 deletions(-) --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -1877,8 +1877,8 @@ 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; } @@ -1895,8 +1895,8 @@ 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; } @@ -1959,7 +1959,7 @@ static int __core_scsi3_write_aptpl_to_f 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"; @@ -1973,25 +1973,26 @@ static sense_reason_t core_scsi3_update_ 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; } --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -407,7 +407,7 @@ 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;