Merge tag 'xfs-for-linus-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "There's quite a lot in this request, and there's some cross-over with
  ext4, dax and quota code due to the nature of the changes being made.

  As for the rest of the XFS changes, there are lots of little things
  all over the place, which add up to a lot of changes in the end.

  The major changes are that we've reduced the size of the struct
  xfs_inode by ~100 bytes (gives an inode cache footprint reduction of
  >10%), the writepage code now only does a single set of mapping tree
  lockups so uses less CPU, delayed allocation reservations won't
  overrun under random write loads anymore, and we added compile time
  verification for on-disk structure sizes so we find out when a commit
  or platform/compiler change breaks the on disk structure as early as
  possible.

  Change summary:

   - error propagation for direct IO failures fixes for both XFS and
     ext4
   - new quota interfaces and XFS implementation for iterating all the
     quota IDs in the filesystem
   - locking fixes for real-time device extent allocation
   - reduction of duplicate information in the xfs and vfs inode, saving
     roughly 100 bytes of memory per cached inode.
   - buffer flag cleanup
   - rework of the writepage code to use the generic write clustering
     mechanisms
   - several fixes for inode flag based DAX enablement
   - rework of remount option parsing
   - compile time verification of on-disk format structure sizes
   - delayed allocation reservation overrun fixes
   - lots of little error handling fixes
   - small memory leak fixes
   - enable xfsaild freezing again"

* tag 'xfs-for-linus-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (66 commits)
  xfs: always set rvalp in xfs_dir2_node_trim_free
  xfs: ensure committed is initialized in xfs_trans_roll
  xfs: borrow indirect blocks from freed extent when available
  xfs: refactor delalloc indlen reservation split into helper
  xfs: update freeblocks counter after extent deletion
  xfs: debug mode forced buffered write failure
  xfs: remove impossible condition
  xfs: check sizes of XFS on-disk structures at compile time
  xfs: ioends require logically contiguous file offsets
  xfs: use named array initializers for log item dumping
  xfs: fix computation of inode btree maxlevels
  xfs: reinitialise per-AG structures if geometry changes during recovery
  xfs: remove xfs_trans_get_block_res
  xfs: fix up inode32/64 (re)mount handling
  xfs: fix format specifier , should be %llx and not %llu
  xfs: sanitize remount options
  xfs: convert mount option parsing to tokens
  xfs: fix two memory leaks in xfs_attr_list.c error paths
  xfs: XFS_DIFLAG2_DAX limited by PAGE_SIZE
  xfs: dynamically switch modes when XFS_DIFLAG2_DAX is set/cleared
  ...

1 files changed, 286 insertions, 242 deletions

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 59c9b7bd958d..d760934109b5 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -45,6 +45,7 @@
 #include "xfs_filestream.h"
 #include "xfs_quota.h"
 #include "xfs_sysfs.h"
+#include "xfs_ondisk.h"
 
 #include <linux/namei.h>
 #include <linux/init.h>
@@ -65,83 +66,85 @@ static struct kset *xfs_kset;		/* top-level xfs sysfs dir */
 static struct xfs_kobj xfs_dbg_kobj;	/* global debug sysfs attrs */
 #endif
 
-#define MNTOPT_LOGBUFS	"logbufs"	/* number of XFS log buffers */
-#define MNTOPT_LOGBSIZE	"logbsize"	/* size of XFS log buffers */
-#define MNTOPT_LOGDEV	"logdev"	/* log device */
-#define MNTOPT_RTDEV	"rtdev"		/* realtime I/O device */
-#define MNTOPT_BIOSIZE	"biosize"	/* log2 of preferred buffered io size */
-#define MNTOPT_WSYNC	"wsync"		/* safe-mode nfs compatible mount */
-#define MNTOPT_NOALIGN	"noalign"	/* turn off stripe alignment */
-#define MNTOPT_SWALLOC	"swalloc"	/* turn on stripe width allocation */
-#define MNTOPT_SUNIT	"sunit"		/* data volume stripe unit */
-#define MNTOPT_SWIDTH	"swidth"	/* data volume stripe width */
-#define MNTOPT_NOUUID	"nouuid"	/* ignore filesystem UUID */
-#define MNTOPT_MTPT	"mtpt"		/* filesystem mount point */
-#define MNTOPT_GRPID	"grpid"		/* group-ID from parent directory */
-#define MNTOPT_NOGRPID	"nogrpid"	/* group-ID from current process */
-#define MNTOPT_BSDGROUPS    "bsdgroups"    /* group-ID from parent directory */
-#define MNTOPT_SYSVGROUPS   "sysvgroups"   /* group-ID from current process */
-#define MNTOPT_ALLOCSIZE    "allocsize"    /* preferred allocation size */
-#define MNTOPT_NORECOVERY   "norecovery"   /* don't run XFS recovery */
-#define MNTOPT_BARRIER	"barrier"	/* use writer barriers for log write and
-					 * unwritten extent conversion */
-#define MNTOPT_NOBARRIER "nobarrier"	/* .. disable */
-#define MNTOPT_64BITINODE   "inode64"	/* inodes can be allocated anywhere */
-#define MNTOPT_32BITINODE   "inode32"	/* inode allocation limited to
-					 * XFS_MAXINUMBER_32 */
-#define MNTOPT_IKEEP	"ikeep"		/* do not free empty inode clusters */
-#define MNTOPT_NOIKEEP	"noikeep"	/* free empty inode clusters */
-#define MNTOPT_LARGEIO	   "largeio"	/* report large I/O sizes in stat() */
-#define MNTOPT_NOLARGEIO   "nolargeio"	/* do not report large I/O sizes
-					 * in stat(). */
-#define MNTOPT_ATTR2	"attr2"		/* do use attr2 attribute format */
-#define MNTOPT_NOATTR2	"noattr2"	/* do not use attr2 attribute format */
-#define MNTOPT_FILESTREAM  "filestreams" /* use filestreams allocator */
-#define MNTOPT_QUOTA	"quota"		/* disk quotas (user) */
-#define MNTOPT_NOQUOTA	"noquota"	/* no quotas */
-#define MNTOPT_USRQUOTA	"usrquota"	/* user quota enabled */
-#define MNTOPT_GRPQUOTA	"grpquota"	/* group quota enabled */
-#define MNTOPT_PRJQUOTA	"prjquota"	/* project quota enabled */
-#define MNTOPT_UQUOTA	"uquota"	/* user quota (IRIX variant) */
-#define MNTOPT_GQUOTA	"gquota"	/* group quota (IRIX variant) */
-#define MNTOPT_PQUOTA	"pquota"	/* project quota (IRIX variant) */
-#define MNTOPT_UQUOTANOENF "uqnoenforce"/* user quota limit enforcement */
-#define MNTOPT_GQUOTANOENF "gqnoenforce"/* group quota limit enforcement */
-#define MNTOPT_PQUOTANOENF "pqnoenforce"/* project quota limit enforcement */
-#define MNTOPT_QUOTANOENF  "qnoenforce"	/* same as uqnoenforce */
-#define MNTOPT_DISCARD	   "discard"	/* Discard unused blocks */
-#define MNTOPT_NODISCARD   "nodiscard"	/* Do not discard unused blocks */
-
-#define MNTOPT_DAX	"dax"		/* Enable direct access to bdev pages */
-
 /*
  * Table driven mount option parser.
- *
- * Currently only used for remount, but it will be used for mount
- * in the future, too.
  */
 enum {
-	Opt_barrier,
-	Opt_nobarrier,
-	Opt_inode64,
-	Opt_inode32,
-	Opt_err
+	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_uqnoenforce, Opt_gqnoenforce, Opt_pqnoenforce, Opt_qnoenforce,
+	Opt_discard, Opt_nodiscard, Opt_dax, Opt_err,
 };
 
 static const match_table_t tokens = {
-	{Opt_barrier, "barrier"},
-	{Opt_nobarrier, "nobarrier"},
-	{Opt_inode64, "inode64"},
-	{Opt_inode32, "inode32"},
-	{Opt_err, NULL}
+	{Opt_logbufs,	"logbufs=%u"},	/* number of XFS log buffers */
+	{Opt_logbsize,	"logbsize=%s"},	/* size of XFS log buffers */
+	{Opt_logdev,	"logdev=%s"},	/* log device */
+	{Opt_rtdev,	"rtdev=%s"},	/* realtime I/O device */
+	{Opt_biosize,	"biosize=%u"},	/* log2 of preferred buffered io size */
+	{Opt_wsync,	"wsync"},	/* safe-mode nfs compatible mount */
+	{Opt_noalign,	"noalign"},	/* turn off stripe alignment */
+	{Opt_swalloc,	"swalloc"},	/* turn on stripe width allocation */
+	{Opt_sunit,	"sunit=%u"},	/* data volume stripe unit */
+	{Opt_swidth,	"swidth=%u"},	/* data volume stripe width */
+	{Opt_nouuid,	"nouuid"},	/* ignore filesystem UUID */
+	{Opt_mtpt,	"mtpt"},	/* filesystem mount point */
+	{Opt_grpid,	"grpid"},	/* group-ID from parent directory */
+	{Opt_nogrpid,	"nogrpid"},	/* group-ID from current process */
+	{Opt_bsdgroups,	"bsdgroups"},	/* group-ID from parent directory */
+	{Opt_sysvgroups,"sysvgroups"},	/* group-ID from current process */
+	{Opt_allocsize,	"allocsize=%s"},/* preferred allocation size */
+	{Opt_norecovery,"norecovery"},	/* don't run XFS recovery */
+	{Opt_barrier,	"barrier"},	/* use writer barriers for log write and
+					 * unwritten extent conversion */
+	{Opt_nobarrier,	"nobarrier"},	/* .. disable */
+	{Opt_inode64,	"inode64"},	/* inodes can be allocated anywhere */
+	{Opt_inode32,   "inode32"},	/* inode allocation limited to
+					 * XFS_MAXINUMBER_32 */
+	{Opt_ikeep,	"ikeep"},	/* do not free empty inode clusters */
+	{Opt_noikeep,	"noikeep"},	/* free empty inode clusters */
+	{Opt_largeio,	"largeio"},	/* report large I/O sizes in stat() */
+	{Opt_nolargeio,	"nolargeio"},	/* do not report large I/O sizes
+					 * in stat(). */
+	{Opt_attr2,	"attr2"},	/* do use attr2 attribute format */
+	{Opt_noattr2,	"noattr2"},	/* do not use attr2 attribute format */
+	{Opt_filestreams,"filestreams"},/* use filestreams allocator */
+	{Opt_quota,	"quota"},	/* disk quotas (user) */
+	{Opt_noquota,	"noquota"},	/* no quotas */
+	{Opt_usrquota,	"usrquota"},	/* user quota enabled */
+	{Opt_grpquota,	"grpquota"},	/* group quota enabled */
+	{Opt_prjquota,	"prjquota"},	/* project quota enabled */
+	{Opt_uquota,	"uquota"},	/* user quota (IRIX variant) */
+	{Opt_gquota,	"gquota"},	/* group quota (IRIX variant) */
+	{Opt_pquota,	"pquota"},	/* project quota (IRIX variant) */
+	{Opt_uqnoenforce,"uqnoenforce"},/* user quota limit enforcement */
+	{Opt_gqnoenforce,"gqnoenforce"},/* group quota limit enforcement */
+	{Opt_pqnoenforce,"pqnoenforce"},/* project quota limit enforcement */
+	{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 */
+	{Opt_err,	NULL},
 };
 
 
 STATIC int
-suffix_kstrtoint(char *s, unsigned int base, int *res)
+suffix_kstrtoint(const substring_t *s, unsigned int base, int *res)
 {
 	int	last, shift_left_factor = 0, _res;
-	char	*value = s;
+	char	*value;
+	int	ret = 0;
+
+	value = match_strdup(s);
+	if (!value)
+		return -ENOMEM;
 
 	last = strlen(value) - 1;
 	if (value[last] == 'K' || value[last] == 'k') {
@@ -157,10 +160,11 @@ suffix_kstrtoint(char *s, unsigned int base, int *res)
 		value[last] = '\0';
 	}
 
-	if (kstrtoint(s, base, &_res))
-		return -EINVAL;
+	if (kstrtoint(value, base, &_res))
+		ret = -EINVAL;
+	kfree(value);
 	*res = _res << shift_left_factor;
-	return 0;
+	return ret;
 }
 
 /*
@@ -169,14 +173,19 @@ suffix_kstrtoint(char *s, unsigned int base, int *res)
  *
  * Note that this function leaks the various device name allocations on
  * failure.  The caller takes care of them.
+ *
+ * *sb is const because this is also used to test options on the remount
+ * path, and we don't want this to have any side effects at remount time.
+ * Today this function does not change *sb, but just to future-proof...
  */
 STATIC int
 xfs_parseargs(
 	struct xfs_mount	*mp,
 	char			*options)
 {
-	struct super_block	*sb = mp->m_super;
-	char			*this_char, *value;
+	const struct super_block *sb = mp->m_super;
+	char			*p;
+	substring_t		args[MAX_OPT_ARGS];
 	int			dsunit = 0;
 	int			dswidth = 0;
 	int			iosize = 0;
@@ -217,152 +226,152 @@ xfs_parseargs(
 	if (!options)
 		goto done;
 
-	while ((this_char = strsep(&options, ",")) != NULL) {
-		if (!*this_char)
+	while ((p = strsep(&options, ",")) != NULL) {
+		int		token;
+
+		if (!*p)
 			continue;
-		if ((value = strchr(this_char, '=')) != NULL)
-			*value++ = 0;
 
-		if (!strcmp(this_char, MNTOPT_LOGBUFS)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
-				return -EINVAL;
-			}
-			if (kstrtoint(value, 10, &mp->m_logbufs))
-				return -EINVAL;
-		} else if (!strcmp(this_char, MNTOPT_LOGBSIZE)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
-				return -EINVAL;
-			}
-			if (suffix_kstrtoint(value, 10, &mp->m_logbsize))
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_logbufs:
+			if (match_int(args, &mp->m_logbufs))
 				return -EINVAL;
-		} else if (!strcmp(this_char, MNTOPT_LOGDEV)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
+			break;
+		case Opt_logbsize:
+			if (suffix_kstrtoint(args, 10, &mp->m_logbsize))
 				return -EINVAL;
-			}
-			mp->m_logname = kstrndup(value, MAXNAMELEN, GFP_KERNEL);
+			break;
+		case Opt_logdev:
+			mp->m_logname = match_strdup(args);
 			if (!mp->m_logname)
 				return -ENOMEM;
-		} else if (!strcmp(this_char, MNTOPT_MTPT)) {
-			xfs_warn(mp, "%s option not allowed on this system",
-				this_char);
+			break;
+		case Opt_mtpt:
+			xfs_warn(mp, "%s option not allowed on this system", p);
 			return -EINVAL;
-		} else if (!strcmp(this_char, MNTOPT_RTDEV)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
-				return -EINVAL;
-			}
-			mp->m_rtname = kstrndup(value, MAXNAMELEN, GFP_KERNEL);
+		case Opt_rtdev:
+			mp->m_rtname = match_strdup(args);
 			if (!mp->m_rtname)
 				return -ENOMEM;
-		} else if (!strcmp(this_char, MNTOPT_ALLOCSIZE) ||
-			   !strcmp(this_char, MNTOPT_BIOSIZE)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
-				return -EINVAL;
-			}
-			if (suffix_kstrtoint(value, 10, &iosize))
+			break;
+		case Opt_allocsize:
+		case Opt_biosize:
+			if (suffix_kstrtoint(args, 10, &iosize))
 				return -EINVAL;
 			iosizelog = ffs(iosize) - 1;
-		} else if (!strcmp(this_char, MNTOPT_GRPID) ||
-			   !strcmp(this_char, MNTOPT_BSDGROUPS)) {
+			break;
+		case Opt_grpid:
+		case Opt_bsdgroups:
 			mp->m_flags |= XFS_MOUNT_GRPID;
-		} else if (!strcmp(this_char, MNTOPT_NOGRPID) ||
-			   !strcmp(this_char, MNTOPT_SYSVGROUPS)) {
+			break;
+		case Opt_nogrpid:
+		case Opt_sysvgroups:
 			mp->m_flags &= ~XFS_MOUNT_GRPID;
-		} else if (!strcmp(this_char, MNTOPT_WSYNC)) {
+			break;
+		case Opt_wsync:
 			mp->m_flags |= XFS_MOUNT_WSYNC;
-		} else if (!strcmp(this_char, MNTOPT_NORECOVERY)) {
+			break;
+		case Opt_norecovery:
 			mp->m_flags |= XFS_MOUNT_NORECOVERY;
-		} else if (!strcmp(this_char, MNTOPT_NOALIGN)) {
+			break;
+		case Opt_noalign:
 			mp->m_flags |= XFS_MOUNT_NOALIGN;
-		} else if (!strcmp(this_char, MNTOPT_SWALLOC)) {
+			break;
+		case Opt_swalloc:
 			mp->m_flags |= XFS_MOUNT_SWALLOC;
-		} else if (!strcmp(this_char, MNTOPT_SUNIT)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
-				return -EINVAL;
-			}
-			if (kstrtoint(value, 10, &dsunit))
-				return -EINVAL;
-		} else if (!strcmp(this_char, MNTOPT_SWIDTH)) {
-			if (!value || !*value) {
-				xfs_warn(mp, "%s option requires an argument",
-					this_char);
+			break;
+		case Opt_sunit:
+			if (match_int(args, &dsunit))
 				return -EINVAL;
-			}
-			if (kstrtoint(value, 10, &dswidth))
+			break;
+		case Opt_swidth:
+			if (match_int(args, &dswidth))
 				return -EINVAL;
-		} else if (!strcmp(this_char, MNTOPT_32BITINODE)) {
+			break;
+		case Opt_inode32:
 			mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
-		} else if (!strcmp(this_char, MNTOPT_64BITINODE)) {
+			break;
+		case Opt_inode64:
 			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
-		} else if (!strcmp(this_char, MNTOPT_NOUUID)) {
+			break;
+		case Opt_nouuid:
 			mp->m_flags |= XFS_MOUNT_NOUUID;
-		} else if (!strcmp(this_char, MNTOPT_BARRIER)) {
+			break;
+		case Opt_barrier:
 			mp->m_flags |= XFS_MOUNT_BARRIER;
-		} else if (!strcmp(this_char, MNTOPT_NOBARRIER)) {
+			break;
+		case Opt_nobarrier:
 			mp->m_flags &= ~XFS_MOUNT_BARRIER;
-		} else if (!strcmp(this_char, MNTOPT_IKEEP)) {
+			break;
+		case Opt_ikeep:
 			mp->m_flags |= XFS_MOUNT_IKEEP;
-		} else if (!strcmp(this_char, MNTOPT_NOIKEEP)) {
+			break;
+		case Opt_noikeep:
 			mp->m_flags &= ~XFS_MOUNT_IKEEP;
-		} else if (!strcmp(this_char, MNTOPT_LARGEIO)) {
+			break;
+		case Opt_largeio:
 			mp->m_flags &= ~XFS_MOUNT_COMPAT_IOSIZE;
-		} else if (!strcmp(this_char, MNTOPT_NOLARGEIO)) {
+			break;
+		case Opt_nolargeio:
 			mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
-		} else if (!strcmp(this_char, MNTOPT_ATTR2)) {
+			break;
+		case Opt_attr2:
 			mp->m_flags |= XFS_MOUNT_ATTR2;
-		} else if (!strcmp(this_char, MNTOPT_NOATTR2)) {
+			break;
+		case Opt_noattr2:
 			mp->m_flags &= ~XFS_MOUNT_ATTR2;
 			mp->m_flags |= XFS_MOUNT_NOATTR2;
-		} else if (!strcmp(this_char, MNTOPT_FILESTREAM)) {
+			break;
+		case Opt_filestreams:
 			mp->m_flags |= XFS_MOUNT_FILESTREAMS;
-		} else if (!strcmp(this_char, MNTOPT_NOQUOTA)) {
+			break;
+		case Opt_noquota:
 			mp->m_qflags &= ~XFS_ALL_QUOTA_ACCT;
 			mp->m_qflags &= ~XFS_ALL_QUOTA_ENFD;
 			mp->m_qflags &= ~XFS_ALL_QUOTA_ACTIVE;
-		} else if (!strcmp(this_char, MNTOPT_QUOTA) ||
-			   !strcmp(this_char, MNTOPT_UQUOTA) ||
-			   !strcmp(this_char, MNTOPT_USRQUOTA)) {
+			break;
+		case Opt_quota:
+		case Opt_uquota:
+		case Opt_usrquota:
 			mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE |
 					 XFS_UQUOTA_ENFD);
-		} else if (!strcmp(this_char, MNTOPT_QUOTANOENF) ||
-			   !strcmp(this_char, MNTOPT_UQUOTANOENF)) {
+			break;
+		case Opt_qnoenforce:
+		case Opt_uqnoenforce:
 			mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE);
 			mp->m_qflags &= ~XFS_UQUOTA_ENFD;
-		} else if (!strcmp(this_char, MNTOPT_PQUOTA) ||
-			   !strcmp(this_char, MNTOPT_PRJQUOTA)) {
+			break;
+		case Opt_pquota:
+		case Opt_prjquota:
 			mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE |
 					 XFS_PQUOTA_ENFD);
-		} else if (!strcmp(this_char, MNTOPT_PQUOTANOENF)) {
+			break;
+		case Opt_pqnoenforce:
 			mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE);
 			mp->m_qflags &= ~XFS_PQUOTA_ENFD;
-		} else if (!strcmp(this_char, MNTOPT_GQUOTA) ||
-			   !strcmp(this_char, MNTOPT_GRPQUOTA)) {
+		case Opt_gquota:
+		case Opt_grpquota:
 			mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE |
 					 XFS_GQUOTA_ENFD);
-		} else if (!strcmp(this_char, MNTOPT_GQUOTANOENF)) {
+			break;
+		case Opt_gqnoenforce:
 			mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE);
 			mp->m_qflags &= ~XFS_GQUOTA_ENFD;
-		} else if (!strcmp(this_char, MNTOPT_DISCARD)) {
+			break;
+		case Opt_discard:
 			mp->m_flags |= XFS_MOUNT_DISCARD;
-		} else if (!strcmp(this_char, MNTOPT_NODISCARD)) {
+			break;
+		case Opt_nodiscard:
 			mp->m_flags &= ~XFS_MOUNT_DISCARD;
+			break;
 #ifdef CONFIG_FS_DAX
-		} else if (!strcmp(this_char, MNTOPT_DAX)) {
+		case Opt_dax:
 			mp->m_flags |= XFS_MOUNT_DAX;
+			break;
 #endif
-		} else {
-			xfs_warn(mp, "unknown mount option [%s].", this_char);
+		default:
+			xfs_warn(mp, "unknown mount option [%s].", p);
 			return -EINVAL;
 		}
 	}
@@ -461,25 +470,25 @@ xfs_showargs(
 {
 	static struct proc_xfs_info xfs_info_set[] = {
 		/* the few simple ones we can get from the mount struct */
-		{ XFS_MOUNT_IKEEP,		"," MNTOPT_IKEEP },
-		{ XFS_MOUNT_WSYNC,		"," MNTOPT_WSYNC },
-		{ XFS_MOUNT_NOALIGN,		"," MNTOPT_NOALIGN },
-		{ XFS_MOUNT_SWALLOC,		"," MNTOPT_SWALLOC },
-		{ XFS_MOUNT_NOUUID,		"," MNTOPT_NOUUID },
-		{ XFS_MOUNT_NORECOVERY,		"," MNTOPT_NORECOVERY },
-		{ XFS_MOUNT_ATTR2,		"," MNTOPT_ATTR2 },
-		{ XFS_MOUNT_FILESTREAMS,	"," MNTOPT_FILESTREAM },
-		{ XFS_MOUNT_GRPID,		"," MNTOPT_GRPID },
-		{ XFS_MOUNT_DISCARD,		"," MNTOPT_DISCARD },
-		{ XFS_MOUNT_SMALL_INUMS,	"," MNTOPT_32BITINODE },
-		{ XFS_MOUNT_DAX,		"," MNTOPT_DAX },
+		{ XFS_MOUNT_IKEEP,		",ikeep" },
+		{ XFS_MOUNT_WSYNC,		",wsync" },
+		{ XFS_MOUNT_NOALIGN,		",noalign" },
+		{ XFS_MOUNT_SWALLOC,		",swalloc" },
+		{ XFS_MOUNT_NOUUID,		",nouuid" },
+		{ XFS_MOUNT_NORECOVERY,		",norecovery" },
+		{ XFS_MOUNT_ATTR2,		",attr2" },
+		{ XFS_MOUNT_FILESTREAMS,	",filestreams" },
+		{ XFS_MOUNT_GRPID,		",grpid" },
+		{ XFS_MOUNT_DISCARD,		",discard" },
+		{ XFS_MOUNT_SMALL_INUMS,	",inode32" },
+		{ XFS_MOUNT_DAX,		",dax" },
 		{ 0, NULL }
 	};
 	static struct proc_xfs_info xfs_info_unset[] = {
 		/* the few simple ones we can get from the mount struct */
-		{ XFS_MOUNT_COMPAT_IOSIZE,	"," MNTOPT_LARGEIO },
-		{ XFS_MOUNT_BARRIER,		"," MNTOPT_NOBARRIER },
-		{ XFS_MOUNT_SMALL_INUMS,	"," MNTOPT_64BITINODE },
+		{ XFS_MOUNT_COMPAT_IOSIZE,	",largeio" },
+		{ XFS_MOUNT_BARRIER,		",nobarrier" },
+		{ XFS_MOUNT_SMALL_INUMS,	",inode64" },
 		{ 0, NULL }
 	};
 	struct proc_xfs_info	*xfs_infop;
@@ -494,46 +503,46 @@ xfs_showargs(
 	}
 
 	if (mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)
-		seq_printf(m, "," MNTOPT_ALLOCSIZE "=%dk",
+		seq_printf(m, ",allocsize=%dk",
 				(int)(1 << mp->m_writeio_log) >> 10);
 
 	if (mp->m_logbufs > 0)
-		seq_printf(m, "," MNTOPT_LOGBUFS "=%d", mp->m_logbufs);
+		seq_printf(m, ",logbufs=%d", mp->m_logbufs);
 	if (mp->m_logbsize > 0)
-		seq_printf(m, "," MNTOPT_LOGBSIZE "=%dk", mp->m_logbsize >> 10);
+		seq_printf(m, ",logbsize=%dk", mp->m_logbsize >> 10);
 
 	if (mp->m_logname)
-		seq_show_option(m, MNTOPT_LOGDEV, mp->m_logname);
+		seq_show_option(m, "logdev", mp->m_logname);
 	if (mp->m_rtname)
-		seq_show_option(m, MNTOPT_RTDEV, mp->m_rtname);
+		seq_show_option(m, "rtdev", mp->m_rtname);
 
 	if (mp->m_dalign > 0)
-		seq_printf(m, "," MNTOPT_SUNIT "=%d",
+		seq_printf(m, ",sunit=%d",
 				(int)XFS_FSB_TO_BB(mp, mp->m_dalign));
 	if (mp->m_swidth > 0)
-		seq_printf(m, "," MNTOPT_SWIDTH "=%d",
+		seq_printf(m, ",swidth=%d",
 				(int)XFS_FSB_TO_BB(mp, mp->m_swidth));
 
 	if (mp->m_qflags & (XFS_UQUOTA_ACCT|XFS_UQUOTA_ENFD))
-		seq_puts(m, "," MNTOPT_USRQUOTA);
+		seq_puts(m, ",usrquota");
 	else if (mp->m_qflags & XFS_UQUOTA_ACCT)
-		seq_puts(m, "," MNTOPT_UQUOTANOENF);
+		seq_puts(m, ",uqnoenforce");
 
 	if (mp->m_qflags & XFS_PQUOTA_ACCT) {
 		if (mp->m_qflags & XFS_PQUOTA_ENFD)
-			seq_puts(m, "," MNTOPT_PRJQUOTA);
+			seq_puts(m, ",prjquota");
 		else
-			seq_puts(m, "," MNTOPT_PQUOTANOENF);
+			seq_puts(m, ",pqnoenforce");
 	}
 	if (mp->m_qflags & XFS_GQUOTA_ACCT) {
 		if (mp->m_qflags & XFS_GQUOTA_ENFD)
-			seq_puts(m, "," MNTOPT_GRPQUOTA);
+			seq_puts(m, ",grpquota");
 		else
-			seq_puts(m, "," MNTOPT_GQUOTANOENF);
+			seq_puts(m, ",gqnoenforce");
 	}
 
 	if (!(mp->m_qflags & XFS_ALL_QUOTA_ACCT))
-		seq_puts(m, "," MNTOPT_NOQUOTA);
+		seq_puts(m, ",noquota");
 
 	return 0;
 }
@@ -572,23 +581,35 @@ xfs_max_file_offset(
 }
 
 /*
- * xfs_set_inode32() and xfs_set_inode64() are passed an agcount
- * because in the growfs case, mp->m_sb.sb_agcount is not updated
- * yet to the potentially higher ag count.
+ * Set parameters for inode allocation heuristics, taking into account
+ * filesystem size and inode32/inode64 mount options; i.e. specifically
+ * whether or not XFS_MOUNT_SMALL_INUMS is set.
+ *
+ * Inode allocation patterns are altered only if inode32 is requested
+ * (XFS_MOUNT_SMALL_INUMS), and the filesystem is sufficiently large.
+ * If altered, XFS_MOUNT_32BITINODES is set as well.
+ *
+ * An agcount independent of that in the mount structure is provided
+ * because in the growfs case, mp->m_sb.sb_agcount is not yet updated
+ * to the potentially higher ag count.
+ *
+ * Returns the maximum AG index which may contain inodes.
  */
 xfs_agnumber_t
-xfs_set_inode32(struct xfs_mount *mp, xfs_agnumber_t agcount)
+xfs_set_inode_alloc(
+	struct xfs_mount *mp,
+	xfs_agnumber_t	agcount)
 {
-	xfs_agnumber_t	index = 0;
+	xfs_agnumber_t	index;
 	xfs_agnumber_t	maxagi = 0;
 	xfs_sb_t	*sbp = &mp->m_sb;
 	xfs_agnumber_t	max_metadata;
 	xfs_agino_t	agino;
 	xfs_ino_t	ino;
-	xfs_perag_t	*pag;
 
-	/* Calculate how much should be reserved for inodes to meet
-	 * the max inode percentage.
+	/*
+	 * Calculate how much should be reserved for inodes to meet
+	 * the max inode percentage.  Used only for inode32.
 	 */
 	if (mp->m_maxicount) {
 		__uint64_t	icount;
@@ -602,54 +623,48 @@ xfs_set_inode32(struct xfs_mount *mp, xfs_agnumber_t agcount)
 		max_metadata = agcount;
 	}
 
+	/* Get the last possible inode in the filesystem */
 	agino =	XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
+	ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
+
+	/*
+	 * If user asked for no more than 32-bit inodes, and the fs is
+	 * sufficiently large, set XFS_MOUNT_32BITINODES if we must alter
+	 * the allocator to accommodate the request.
+	 */
+	if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
+		mp->m_flags |= XFS_MOUNT_32BITINODES;
+	else
+		mp->m_flags &= ~XFS_MOUNT_32BITINODES;
 
 	for (index = 0; index < agcount; index++) {
-		ino = XFS_AGINO_TO_INO(mp, index, agino);
+		struct xfs_perag	*pag;
 
-		if (ino > XFS_MAXINUMBER_32) {
-			pag = xfs_perag_get(mp, index);
-			pag->pagi_inodeok = 0;
-			pag->pagf_metadata = 0;
-			xfs_perag_put(pag);
-			continue;
-		}
+		ino = XFS_AGINO_TO_INO(mp, index, agino);
 
 		pag = xfs_perag_get(mp, index);
-		pag->pagi_inodeok = 1;
-		maxagi++;
-		if (index < max_metadata)
-			pag->pagf_metadata = 1;
-		xfs_perag_put(pag);
-	}
-	mp->m_flags |= (XFS_MOUNT_32BITINODES |
-			XFS_MOUNT_SMALL_INUMS);
 
-	return maxagi;
-}
-
-xfs_agnumber_t
-xfs_set_inode64(struct xfs_mount *mp, xfs_agnumber_t agcount)
-{
-	xfs_agnumber_t index = 0;
-
-	for (index = 0; index < agcount; index++) {
-		struct xfs_perag	*pag;
+		if (mp->m_flags & XFS_MOUNT_32BITINODES) {
+			if (ino > XFS_MAXINUMBER_32) {
+				pag->pagi_inodeok = 0;
+				pag->pagf_metadata = 0;
+			} else {
+				pag->pagi_inodeok = 1;
+				maxagi++;
+				if (index < max_metadata)
+					pag->pagf_metadata = 1;
+				else
+					pag->pagf_metadata = 0;
+			}
+		} else {
+			pag->pagi_inodeok = 1;
+			pag->pagf_metadata = 0;
+		}
 
-		pag = xfs_perag_get(mp, index);
-		pag->pagi_inodeok = 1;
-		pag->pagf_metadata = 0;
 		xfs_perag_put(pag);
 	}
 
-	/* There is no need for lock protection on m_flags,
-	 * the rw_semaphore of the VFS superblock is locked
-	 * during mount/umount/remount operations, so this is
-	 * enough to avoid concurency on the m_flags field
-	 */
-	mp->m_flags &= ~(XFS_MOUNT_32BITINODES |
-			 XFS_MOUNT_SMALL_INUMS);
-	return index;
+	return (mp->m_flags & XFS_MOUNT_32BITINODES) ? maxagi : agcount;
 }
 
 STATIC int
@@ -1166,6 +1181,27 @@ xfs_quiesce_attr(
 }
 
 STATIC int
+xfs_test_remount_options(
+	struct super_block	*sb,
+	struct xfs_mount	*mp,
+	char			*options)
+{
+	int			error = 0;
+	struct xfs_mount	*tmp_mp;
+
+	tmp_mp = kmem_zalloc(sizeof(*tmp_mp), KM_MAYFAIL);
+	if (!tmp_mp)
+		return -ENOMEM;
+
+	tmp_mp->m_super = sb;
+	error = xfs_parseargs(tmp_mp, options);
+	xfs_free_fsname(tmp_mp);
+	kfree(tmp_mp);
+
+	return error;
+}
+
+STATIC int
 xfs_fs_remount(
 	struct super_block	*sb,
 	int			*flags,
@@ -1177,6 +1213,11 @@ xfs_fs_remount(
 	char			*p;
 	int			error;
 
+	/* First, check for complete junk; i.e. invalid options */
+	error = xfs_test_remount_options(sb, mp, options);
+	if (error)
+		return error;
+
 	sync_filesystem(sb);
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -1193,10 +1234,12 @@ xfs_fs_remount(
 			mp->m_flags &= ~XFS_MOUNT_BARRIER;
 			break;
 		case Opt_inode64:
-			mp->m_maxagi = xfs_set_inode64(mp, sbp->sb_agcount);
+			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
+			mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
 			break;
 		case Opt_inode32:
-			mp->m_maxagi = xfs_set_inode32(mp, sbp->sb_agcount);
+			mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
+			mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
 			break;
 		default:
 			/*
@@ -1344,9 +1387,8 @@ xfs_finish_flags(
 	 */
 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
 	    (mp->m_flags & XFS_MOUNT_NOATTR2)) {
-		xfs_warn(mp,
-"Cannot mount a V5 filesystem as %s. %s is always enabled for V5 filesystems.",
-			MNTOPT_NOATTR2, MNTOPT_ATTR2);
+		xfs_warn(mp, "Cannot mount a V5 filesystem as noattr2. "
+			     "attr2 is always enabled for V5 filesystems.");
 		return -EINVAL;
 	}
 
@@ -1817,6 +1859,8 @@ init_xfs_fs(void)
 {
 	int			error;
 
+	xfs_check_ondisk_structs();
+
 	printk(KERN_INFO XFS_VERSION_STRING " with "
 			 XFS_BUILD_OPTIONS " enabled\n");