xfs: remove deprecated barrier/nobarrier mount

The barrier mount options have been no-ops and deprecated since

4cf4573 xfs: deprecate barrier/nobarrier mount option

i.e. kernel 4.10 / December 2016, with a stated deprecation schedule
after v4.15. Should be fair game to remove them now.

Signed-off-by: Eric Sandeen <[e-mail]>
Reviewed-by: Carlos Maiolino <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
Signed-off-by: Darrick J. Wong <[e-mail]>

Documentation/filesystems/xfs.txt

···
 
   Name				Removal Schedule
   ----				----------------
-  barrier			no earlier than v4.15
-  nobarrier			no earlier than v4.15
 
 
 Removed Mount Options
···
   ihashsize			v4.0
   irixsgid			v4.0
   osyncisdsync/osyncisosync	v4.0
+  barrier			v4.19
+  nobarrier			v4.19
 
 
 sysctls

fs/xfs/xfs_mount.h

···
 #define XFS_MOUNT_SMALL_INUMS	(1ULL << 14)	/* user wants 32bit inodes */
 #define XFS_MOUNT_32BITINODES	(1ULL << 15)	/* inode32 allocator active */
 #define XFS_MOUNT_NOUUID	(1ULL << 16)	/* ignore uuid during mount */
-#define XFS_MOUNT_BARRIER	(1ULL << 17)
 #define XFS_MOUNT_IKEEP		(1ULL << 18)	/* keep empty inode clusters*/
 #define XFS_MOUNT_SWALLOC	(1ULL << 19)	/* turn on stripe width
 						 * allocation */

fs/xfs/xfs_super.c

···
 	Opt_logbufs, Opt_logbsize, Opt_logdev, Opt_rtdev, Opt_biosize,
 	Opt_wsync, Opt_noalign, Opt_swalloc, Opt_sunit, Opt_swidth, Opt_nouuid,
 	Opt_mtpt, Opt_grpid, Opt_nogrpid, Opt_bsdgroups, Opt_sysvgroups,
-	Opt_allocsize, Opt_norecovery, Opt_barrier, Opt_nobarrier,
-	Opt_inode64, Opt_inode32, Opt_ikeep, Opt_noikeep,
-	Opt_largeio, Opt_nolargeio, Opt_attr2, Opt_noattr2, Opt_filestreams,
-	Opt_quota, Opt_noquota, Opt_usrquota, Opt_grpquota, Opt_prjquota,
-	Opt_uquota, Opt_gquota, Opt_pquota,
+	Opt_allocsize, Opt_norecovery, Opt_inode64, Opt_inode32, Opt_ikeep,
+	Opt_noikeep, Opt_largeio, Opt_nolargeio, Opt_attr2, Opt_noattr2,
+	Opt_filestreams, Opt_quota, Opt_noquota, Opt_usrquota, Opt_grpquota,
+	Opt_prjquota, Opt_uquota, Opt_gquota, Opt_pquota,
 	Opt_uqnoenforce, Opt_gqnoenforce, Opt_pqnoenforce, Opt_qnoenforce,
 	Opt_discard, Opt_nodiscard, Opt_dax, Opt_err,
 };
···
 	{Opt_qnoenforce, "qnoenforce"},	/* same as uqnoenforce */
 	{Opt_discard,	"discard"},	/* Discard unused blocks */
 	{Opt_nodiscard,	"nodiscard"},	/* Do not discard unused blocks */
-
 	{Opt_dax,	"dax"},		/* Enable direct access to bdev pages */
-
-	/* Deprecated mount options scheduled for removal */
-	{Opt_barrier,	"barrier"},	/* use writer barriers for log write and
-					 * unwritten extent conversion */
-	{Opt_nobarrier,	"nobarrier"},	/* .. disable */
-
 	{Opt_err,	NULL},
 };
 
···
 	 * Set some default flags that could be cleared by the mount option
 	 * parsing.
 	 */
-	mp->m_flags |= XFS_MOUNT_BARRIER;
 	mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
 
 	/*
···
 			mp->m_flags |= XFS_MOUNT_DAX;
 			break;
 #endif
-		case Opt_barrier:
-			xfs_warn(mp, "%s option is deprecated, ignoring.", p);
-			mp->m_flags |= XFS_MOUNT_BARRIER;
-			break;
-		case Opt_nobarrier:
-			xfs_warn(mp, "%s option is deprecated, ignoring.", p);
-			mp->m_flags &= ~XFS_MOUNT_BARRIER;
-			break;
 		default:
 			xfs_warn(mp, "unknown mount option [%s].", p);
 			return -EINVAL;
···
 	static struct proc_xfs_info xfs_info_unset[] = {
 		/* the few simple ones we can get from the mount struct */
 		{ XFS_MOUNT_COMPAT_IOSIZE,	",largeio" },
-		{ XFS_MOUNT_BARRIER,		",nobarrier" },
 		{ XFS_MOUNT_SMALL_INUMS,	",inode64" },
 		{ 0, NULL }
 	};
···
 
 		token = match_token(p, tokens, args);
 		switch (token) {
-		case Opt_barrier:
-			xfs_warn(mp, "%s option is deprecated, ignoring.", p);
-			mp->m_flags |= XFS_MOUNT_BARRIER;
-			break;
-		case Opt_nobarrier:
-			xfs_warn(mp, "%s option is deprecated, ignoring.", p);
-			mp->m_flags &= ~XFS_MOUNT_BARRIER;
-			break;
 		case Opt_inode64:
 			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
 			mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);