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: Martin Svec <martin.svec@zoner.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 397fb635766a..eec07656eb03 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -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;