svn commit: r324204 - stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Andriy Gapon]

Author: avg
Date: Mon Oct  2 12:47:35 2017
New Revision: 324204
URL: https://svnweb.freebsd.org/changeset/base/324204

Log:
  MFC r323918: MFV r323917: 8648 Fix range locking in ZIL commit codepath
  
  This fixes a problem introduced in r320496, MFC of r308782.

Modified:
  stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
  stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c	Mon Oct  2 12:44:06 2017	(r324203)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c	Mon Oct  2 12:47:35 2017	(r324204)
@@ -1344,7 +1344,7 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio
 	} else { /* indirect write */
 		/*
 		 * Have to lock the whole block to ensure when it's
-		 * written out and it's checksum is being calculated
+		 * written out and its checksum is being calculated
 		 * that no one can change the data. We need to re-check
 		 * blocksize after we get the lock in case it's changed!
 		 */

Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c	Mon Oct  2 12:44:06 2017	(r324203)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c	Mon Oct  2 12:47:35 2017	(r324204)
@@ -1305,7 +1305,6 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zi
 
 	zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
 	zgd->zgd_zilog = zv->zv_zilog;
-	zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
 
 	/*
 	 * Write records come in two flavors: immediate and indirect.
@@ -1314,12 +1313,22 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zi
 	 * sync the data and get a pointer to it (indirect) so that
 	 * we don't have to write the data twice.
 	 */
-	if (buf != NULL) {	/* immediate write */
+	if (buf != NULL) { /* immediate write */
+		zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
+		    RL_READER);
 		error = dmu_read(os, object, offset, size, buf,
 		    DMU_READ_NO_PREFETCH);
-	} else {
+	} else { /* indirect write */
+		/*
+		 * Have to lock the whole block to ensure when it's written out
+		 * and its checksum is being calculated that no one can change
+		 * the data. Contrarily to zfs_get_data we need not re-check
+		 * blocksize after we get the lock because it cannot be changed.
+		 */
 		size = zv->zv_volblocksize;
 		offset = P2ALIGN(offset, size);
+		zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
+		    RL_READER);
 		error = dmu_buf_hold(os, object, offset, zgd, &db,
 		    DMU_READ_NO_PREFETCH);
 		if (error == 0) {