Merge tag 'for-linus-v3.7-rc1' of git://oss.sgi.com/xfs/xfs

Pull xfs update from Ben Myers:
 "Several enhancements and cleanups:

   - make inode32 and inode64 remountable options
   - SEEK_HOLE/SEEK_DATA enhancements
   - cleanup struct declarations in xfs_mount.h"

* tag 'for-linus-v3.7-rc1' of git://oss.sgi.com/xfs/xfs:
  xfs: Make inode32 a remountable option
  xfs: add inode64->inode32 transition into xfs_set_inode32()
  xfs: Fix mp->m_maxagi update during inode64 remount
  xfs: reduce code duplication handling inode32/64 options
  xfs: make inode64 as the default allocation mode
  xfs: Fix m_agirotor reset during AG selection
  Make inode64 a remountable option
  xfs: stop the sync worker before xfs_unmountfs
  xfs: xfs_seek_hole() refinement with hole searching from page cache for unwritten extents
  xfs: xfs_seek_data() refinement with unwritten extents check up from page cache
  xfs: Introduce a helper routine to probe data or hole offset from page cache
  xfs: Remove type argument from xfs_seek_data()/xfs_seek_hole()
  xfs: fix race while discarding buffers [V4]
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: kill struct declarations in xfs_mount.h
  xfs: fix uninitialised variable in xfs_rtbuf_get()

7 files changed, 447 insertions, 80 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 56afcdb2377..1eaeb8be3aa 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -36,6 +36,7 @@
 
 #include <linux/dcache.h>
 #include <linux/falloc.h>
+#include <linux/pagevec.h>
 
 static const struct vm_operations_struct xfs_file_vm_ops;
 
@@ -959,17 +960,232 @@ xfs_vm_page_mkwrite(
 	return block_page_mkwrite(vma, vmf, xfs_get_blocks);
 }
 
+/*
+ * This type is designed to indicate the type of offset we would like
+ * to search from page cache for either xfs_seek_data() or xfs_seek_hole().
+ */
+enum {
+	HOLE_OFF = 0,
+	DATA_OFF,
+};
+
+/*
+ * Lookup the desired type of offset from the given page.
+ *
+ * On success, return true and the offset argument will point to the
+ * start of the region that was found.  Otherwise this function will
+ * return false and keep the offset argument unchanged.
+ */
+STATIC bool
+xfs_lookup_buffer_offset(
+	struct page		*page,
+	loff_t			*offset,
+	unsigned int		type)
+{
+	loff_t			lastoff = page_offset(page);
+	bool			found = false;
+	struct buffer_head	*bh, *head;
+
+	bh = head = page_buffers(page);
+	do {
+		/*
+		 * Unwritten extents that have data in the page
+		 * cache covering them can be identified by the
+		 * BH_Unwritten state flag.  Pages with multiple
+		 * buffers might have a mix of holes, data and
+		 * unwritten extents - any buffer with valid
+		 * data in it should have BH_Uptodate flag set
+		 * on it.
+		 */
+		if (buffer_unwritten(bh) ||
+		    buffer_uptodate(bh)) {
+			if (type == DATA_OFF)
+				found = true;
+		} else {
+			if (type == HOLE_OFF)
+				found = true;
+		}
+
+		if (found) {
+			*offset = lastoff;
+			break;
+		}
+		lastoff += bh->b_size;
+	} while ((bh = bh->b_this_page) != head);
+
+	return found;
+}
+
+/*
+ * This routine is called to find out and return a data or hole offset
+ * from the page cache for unwritten extents according to the desired
+ * type for xfs_seek_data() or xfs_seek_hole().
+ *
+ * The argument offset is used to tell where we start to search from the
+ * page cache.  Map is used to figure out the end points of the range to
+ * lookup pages.
+ *
+ * Return true if the desired type of offset was found, and the argument
+ * offset is filled with that address.  Otherwise, return false and keep
+ * offset unchanged.
+ */
+STATIC bool
+xfs_find_get_desired_pgoff(
+	struct inode		*inode,
+	struct xfs_bmbt_irec	*map,
+	unsigned int		type,
+	loff_t			*offset)
+{
+	struct xfs_inode	*ip = XFS_I(inode);
+	struct xfs_mount	*mp = ip->i_mount;
+	struct pagevec		pvec;
+	pgoff_t			index;
+	pgoff_t			end;
+	loff_t			endoff;
+	loff_t			startoff = *offset;
+	loff_t			lastoff = startoff;
+	bool			found = false;
+
+	pagevec_init(&pvec, 0);
+
+	index = startoff >> PAGE_CACHE_SHIFT;
+	endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
+	end = endoff >> PAGE_CACHE_SHIFT;
+	do {
+		int		want;
+		unsigned	nr_pages;
+		unsigned int	i;
+
+		want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
+		nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
+					  want);
+		/*
+		 * No page mapped into given range.  If we are searching holes
+		 * and if this is the first time we got into the loop, it means
+		 * that the given offset is landed in a hole, return it.
+		 *
+		 * If we have already stepped through some block buffers to find
+		 * holes but they all contains data.  In this case, the last
+		 * offset is already updated and pointed to the end of the last
+		 * mapped page, if it does not reach the endpoint to search,
+		 * that means there should be a hole between them.
+		 */
+		if (nr_pages == 0) {
+			/* Data search found nothing */
+			if (type == DATA_OFF)
+				break;
+
+			ASSERT(type == HOLE_OFF);
+			if (lastoff == startoff || lastoff < endoff) {
+				found = true;
+				*offset = lastoff;
+			}
+			break;
+		}
+
+		/*
+		 * At lease we found one page.  If this is the first time we
+		 * step into the loop, and if the first page index offset is
+		 * greater than the given search offset, a hole was found.
+		 */
+		if (type == HOLE_OFF && lastoff == startoff &&
+		    lastoff < page_offset(pvec.pages[0])) {
+			found = true;
+			break;
+		}
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page	*page = pvec.pages[i];
+			loff_t		b_offset;
+
+			/*
+			 * At this point, the page may be truncated or
+			 * invalidated (changing page->mapping to NULL),
+			 * or even swizzled back from swapper_space to tmpfs
+			 * file mapping. However, page->index will not change
+			 * because we have a reference on the page.
+			 *
+			 * Searching done if the page index is out of range.
+			 * If the current offset is not reaches the end of
+			 * the specified search range, there should be a hole
+			 * between them.
+			 */
+			if (page->index > end) {
+				if (type == HOLE_OFF && lastoff < endoff) {
+					*offset = lastoff;
+					found = true;
+				}
+				goto out;
+			}
+
+			lock_page(page);
+			/*
+			 * Page truncated or invalidated(page->mapping == NULL).
+			 * We can freely skip it and proceed to check the next
+			 * page.
+			 */
+			if (unlikely(page->mapping != inode->i_mapping)) {
+				unlock_page(page);
+				continue;
+			}
+
+			if (!page_has_buffers(page)) {
+				unlock_page(page);
+				continue;
+			}
+
+			found = xfs_lookup_buffer_offset(page, &b_offset, type);
+			if (found) {
+				/*
+				 * The found offset may be less than the start
+				 * point to search if this is the first time to
+				 * come here.
+				 */
+				*offset = max_t(loff_t, startoff, b_offset);
+				unlock_page(page);
+				goto out;
+			}
+
+			/*
+			 * We either searching data but nothing was found, or
+			 * searching hole but found a data buffer.  In either
+			 * case, probably the next page contains the desired
+			 * things, update the last offset to it so.
+			 */
+			lastoff = page_offset(page) + PAGE_SIZE;
+			unlock_page(page);
+		}
+
+		/*
+		 * The number of returned pages less than our desired, search
+		 * done.  In this case, nothing was found for searching data,
+		 * but we found a hole behind the last offset.
+		 */
+		if (nr_pages < want) {
+			if (type == HOLE_OFF) {
+				*offset = lastoff;
+				found = true;
+			}
+			break;
+		}
+
+		index = pvec.pages[i - 1]->index + 1;
+		pagevec_release(&pvec);
+	} while (index <= end);
+
+out:
+	pagevec_release(&pvec);
+	return found;
+}
+
 STATIC loff_t
 xfs_seek_data(
 	struct file		*file,
-	loff_t			start,
-	u32			type)
+	loff_t			start)
 {
 	struct inode		*inode = file->f_mapping->host;
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_bmbt_irec	map[2];
-	int			nmap = 2;
 	loff_t			uninitialized_var(offset);
 	xfs_fsize_t		isize;
 	xfs_fileoff_t		fsbno;
@@ -985,36 +1201,74 @@ xfs_seek_data(
 		goto out_unlock;
 	}
 
-	fsbno = XFS_B_TO_FSBT(mp, start);
-
 	/*
 	 * Try to read extents from the first block indicated
 	 * by fsbno to the end block of the file.
 	 */
+	fsbno = XFS_B_TO_FSBT(mp, start);
 	end = XFS_B_TO_FSB(mp, isize);
+	for (;;) {
+		struct xfs_bmbt_irec	map[2];
+		int			nmap = 2;
+		unsigned int		i;
 
-	error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
-			       XFS_BMAPI_ENTIRE);
-	if (error)
-		goto out_unlock;
+		error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
+				       XFS_BMAPI_ENTIRE);
+		if (error)
+			goto out_unlock;
 
-	/*
-	 * Treat unwritten extent as data extent since it might
-	 * contains dirty data in page cache.
-	 */
-	if (map[0].br_startblock != HOLESTARTBLOCK) {
-		offset = max_t(loff_t, start,
-			       XFS_FSB_TO_B(mp, map[0].br_startoff));
-	} else {
+		/* No extents at given offset, must be beyond EOF */
+		if (nmap == 0) {
+			error = ENXIO;
+			goto out_unlock;
+		}
+
+		for (i = 0; i < nmap; i++) {
+			offset = max_t(loff_t, start,
+				       XFS_FSB_TO_B(mp, map[i].br_startoff));
+
+			/* Landed in a data extent */
+			if (map[i].br_startblock == DELAYSTARTBLOCK ||
+			    (map[i].br_state == XFS_EXT_NORM &&
+			     !isnullstartblock(map[i].br_startblock)))
+				goto out;
+
+			/*
+			 * Landed in an unwritten extent, try to search data
+			 * from page cache.
+			 */
+			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
+				if (xfs_find_get_desired_pgoff(inode, &map[i],
+							DATA_OFF, &offset))
+					goto out;
+			}
+		}
+
+		/*
+		 * map[0] is hole or its an unwritten extent but
+		 * without data in page cache.  Probably means that
+		 * we are reading after EOF if nothing in map[1].
+		 */
 		if (nmap == 1) {
 			error = ENXIO;
 			goto out_unlock;
 		}
 
-		offset = max_t(loff_t, start,
-			       XFS_FSB_TO_B(mp, map[1].br_startoff));
+		ASSERT(i > 1);
+
+		/*
+		 * Nothing was found, proceed to the next round of search
+		 * if reading offset not beyond or hit EOF.
+		 */
+		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
+		start = XFS_FSB_TO_B(mp, fsbno);
+		if (start >= isize) {
+			error = ENXIO;
+			goto out_unlock;
+		}
 	}
 
+out:
 	if (offset != file->f_pos)
 		file->f_pos = offset;
 
@@ -1029,16 +1283,15 @@ out_unlock:
 STATIC loff_t
 xfs_seek_hole(
 	struct file		*file,
-	loff_t			start,
-	u32			type)
+	loff_t			start)
 {
 	struct inode		*inode = file->f_mapping->host;
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 	loff_t			uninitialized_var(offset);
-	loff_t			holeoff;
 	xfs_fsize_t		isize;
 	xfs_fileoff_t		fsbno;
+	xfs_filblks_t		end;
 	uint			lock;
 	int			error;
 
@@ -1054,21 +1307,77 @@ xfs_seek_hole(
 	}
 
 	fsbno = XFS_B_TO_FSBT(mp, start);
-	error = xfs_bmap_first_unused(NULL, ip, 1, &fsbno, XFS_DATA_FORK);
-	if (error)
-		goto out_unlock;
+	end = XFS_B_TO_FSB(mp, isize);
+
+	for (;;) {
+		struct xfs_bmbt_irec	map[2];
+		int			nmap = 2;
+		unsigned int		i;
+
+		error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
+				       XFS_BMAPI_ENTIRE);
+		if (error)
+			goto out_unlock;
+
+		/* No extents at given offset, must be beyond EOF */
+		if (nmap == 0) {
+			error = ENXIO;
+			goto out_unlock;
+		}
+
+		for (i = 0; i < nmap; i++) {
+			offset = max_t(loff_t, start,
+				       XFS_FSB_TO_B(mp, map[i].br_startoff));
+
+			/* Landed in a hole */
+			if (map[i].br_startblock == HOLESTARTBLOCK)
+				goto out;
+
+			/*
+			 * Landed in an unwritten extent, try to search hole
+			 * from page cache.
+			 */
+			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
+				if (xfs_find_get_desired_pgoff(inode, &map[i],
+							HOLE_OFF, &offset))
+					goto out;
+			}
+		}
+
+		/*
+		 * map[0] contains data or its unwritten but contains
+		 * data in page cache, probably means that we are
+		 * reading after EOF.  We should fix offset to point
+		 * to the end of the file(i.e., there is an implicit
+		 * hole at the end of any file).
+		 */
+		if (nmap == 1) {
+			offset = isize;
+			break;
+		}
+
+		ASSERT(i > 1);
 
-	holeoff = XFS_FSB_TO_B(mp, fsbno);
-	if (holeoff <= start)
-		offset = start;
-	else {
 		/*
-		 * xfs_bmap_first_unused() could return a value bigger than
-		 * isize if there are no more holes past the supplied offset.
+		 * Both mappings contains data, proceed to the next round of
+		 * search if the current reading offset not beyond or hit EOF.
 		 */
-		offset = min_t(loff_t, holeoff, isize);
+		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
+		start = XFS_FSB_TO_B(mp, fsbno);
+		if (start >= isize) {
+			offset = isize;
+			break;
+		}
 	}
 
+out:
+	/*
+	 * At this point, we must have found a hole.  However, the returned
+	 * offset may be bigger than the file size as it may be aligned to
+	 * page boundary for unwritten extents, we need to deal with this
+	 * situation in particular.
+	 */
+	offset = min_t(loff_t, offset, isize);
 	if (offset != file->f_pos)
 		file->f_pos = offset;
 
@@ -1092,9 +1401,9 @@ xfs_file_llseek(
 	case SEEK_SET:
 		return generic_file_llseek(file, offset, origin);
 	case SEEK_DATA:
-		return xfs_seek_data(file, offset, origin);
+		return xfs_seek_data(file, offset);
 	case SEEK_HOLE:
-		return xfs_seek_hole(file, offset, origin);
+		return xfs_seek_hole(file, offset);
 	default:
 		return -EINVAL;
 	}
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 5aceb3f8ecd..445bf1aef31 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -431,7 +431,7 @@ xfs_ialloc_next_ag(
 
 	spin_lock(&mp->m_agirotor_lock);
 	agno = mp->m_agirotor;
-	if (++mp->m_agirotor == mp->m_maxagi)
+	if (++mp->m_agirotor >= mp->m_maxagi)
 		mp->m_agirotor = 0;
 	spin_unlock(&mp->m_agirotor_lock);
 
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 29c2f83d414..b2bd3a0e637 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -440,7 +440,7 @@ xfs_initialize_perag(
 	xfs_agnumber_t	agcount,
 	xfs_agnumber_t	*maxagi)
 {
-	xfs_agnumber_t	index, max_metadata;
+	xfs_agnumber_t	index;
 	xfs_agnumber_t	first_initialised = 0;
 	xfs_perag_t	*pag;
 	xfs_agino_t	agino;
@@ -500,43 +500,10 @@ xfs_initialize_perag(
 	else
 		mp->m_flags &= ~XFS_MOUNT_32BITINODES;
 
-	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
-		/*
-		 * Calculate how much should be reserved for inodes to meet
-		 * the max inode percentage.
-		 */
-		if (mp->m_maxicount) {
-			__uint64_t	icount;
-
-			icount = sbp->sb_dblocks * sbp->sb_imax_pct;
-			do_div(icount, 100);
-			icount += sbp->sb_agblocks - 1;
-			do_div(icount, sbp->sb_agblocks);
-			max_metadata = icount;
-		} else {
-			max_metadata = agcount;
-		}
-
-		for (index = 0; index < agcount; index++) {
-			ino = XFS_AGINO_TO_INO(mp, index, agino);
-			if (ino > XFS_MAXINUMBER_32) {
-				index++;
-				break;
-			}
-
-			pag = xfs_perag_get(mp, index);
-			pag->pagi_inodeok = 1;
-			if (index < max_metadata)
-				pag->pagf_metadata = 1;
-			xfs_perag_put(pag);
-		}
-	} else {
-		for (index = 0; index < agcount; index++) {
-			pag = xfs_perag_get(mp, index);
-			pag->pagi_inodeok = 1;
-			xfs_perag_put(pag);
-		}
-	}
+	if (mp->m_flags & XFS_MOUNT_32BITINODES)
+		index = xfs_set_inode32(mp);
+	else
+		index = xfs_set_inode64(mp);
 
 	if (maxagi)
 		*maxagi = index;
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 05a05a7b611..deee09e534d 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -54,12 +54,7 @@ typedef struct xfs_trans_reservations {
 #include "xfs_sync.h"
 
 struct xlog;
-struct xfs_mount_args;
 struct xfs_inode;
-struct xfs_bmbt_irec;
-struct xfs_bmap_free;
-struct xfs_extdelta;
-struct xfs_swapext;
 struct xfs_mru_cache;
 struct xfs_nameops;
 struct xfs_ail;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index e0fd2734189..26a09bd7f97 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -88,6 +88,8 @@ mempool_t *xfs_ioend_pool;
 					 * 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() */
@@ -120,12 +122,18 @@ mempool_t *xfs_ioend_pool;
  * in the future, too.
  */
 enum {
-	Opt_barrier, Opt_nobarrier, Opt_err
+	Opt_barrier,
+	Opt_nobarrier,
+	Opt_inode64,
+	Opt_inode32,
+	Opt_err
 };
 
 static const match_table_t tokens = {
 	{Opt_barrier, "barrier"},
 	{Opt_nobarrier, "nobarrier"},
+	{Opt_inode64, "inode64"},
+	{Opt_inode32, "inode32"},
 	{Opt_err, NULL}
 };
 
@@ -197,7 +205,9 @@ xfs_parseargs(
 	 */
 	mp->m_flags |= XFS_MOUNT_BARRIER;
 	mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
+#if !XFS_BIG_INUMS
 	mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
+#endif
 
 	/*
 	 * These can be overridden by the mount option parsing.
@@ -294,6 +304,8 @@ xfs_parseargs(
 				return EINVAL;
 			}
 			dswidth = simple_strtoul(value, &eov, 10);
+		} else if (!strcmp(this_char, MNTOPT_32BITINODE)) {
+			mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
 		} else if (!strcmp(this_char, MNTOPT_64BITINODE)) {
 			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
 #if !XFS_BIG_INUMS
@@ -492,6 +504,7 @@ xfs_showargs(
 		{ XFS_MOUNT_FILESTREAMS,	"," MNTOPT_FILESTREAM },
 		{ XFS_MOUNT_GRPID,		"," MNTOPT_GRPID },
 		{ XFS_MOUNT_DISCARD,		"," MNTOPT_DISCARD },
+		{ XFS_MOUNT_SMALL_INUMS,	"," MNTOPT_32BITINODE },
 		{ 0, NULL }
 	};
 	static struct proc_xfs_info xfs_info_unset[] = {
@@ -591,6 +604,80 @@ xfs_max_file_offset(
 	return (((__uint64_t)pagefactor) << bitshift) - 1;
 }
 
+xfs_agnumber_t
+xfs_set_inode32(struct xfs_mount *mp)
+{
+	xfs_agnumber_t	index = 0;
+	xfs_agnumber_t	maxagi = 0;
+	xfs_sb_t	*sbp = &mp->m_sb;
+	xfs_agnumber_t	max_metadata;
+	xfs_agino_t	agino =	XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks -1, 0);
+	xfs_ino_t	ino = XFS_AGINO_TO_INO(mp, sbp->sb_agcount -1, agino);
+	xfs_perag_t	*pag;
+
+	/* Calculate how much should be reserved for inodes to meet
+	 * the max inode percentage.
+	 */
+	if (mp->m_maxicount) {
+		__uint64_t	icount;
+
+		icount = sbp->sb_dblocks * sbp->sb_imax_pct;
+		do_div(icount, 100);
+		icount += sbp->sb_agblocks - 1;
+		do_div(icount, sbp->sb_agblocks);
+		max_metadata = icount;
+	} else {
+		max_metadata = sbp->sb_agcount;
+	}
+
+	for (index = 0; index < sbp->sb_agcount; index++) {
+		ino = XFS_AGINO_TO_INO(mp, index, agino);
+
+		if (ino > XFS_MAXINUMBER_32) {
+			pag = xfs_perag_get(mp, index);
+			pag->pagi_inodeok = 0;
+			pag->pagf_metadata = 0;
+			xfs_perag_put(pag);
+			continue;
+		}
+
+		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 index = 0;
+
+	for (index = 0; index < mp->m_sb.sb_agcount; index++) {
+		struct xfs_perag	*pag;
+
+		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;
+}
+
 STATIC int
 xfs_blkdev_get(
 	xfs_mount_t		*mp,
@@ -1056,6 +1143,12 @@ xfs_fs_remount(
 		case Opt_nobarrier:
 			mp->m_flags &= ~XFS_MOUNT_BARRIER;
 			break;
+		case Opt_inode64:
+			mp->m_maxagi = xfs_set_inode64(mp);
+			break;
+		case Opt_inode32:
+			mp->m_maxagi = xfs_set_inode32(mp);
+			break;
 		default:
 			/*
 			 * Logically we would return an error here to prevent
diff --git a/fs/xfs/xfs_super.h b/fs/xfs/xfs_super.h
index 09b0c26b224..9de4a920ba0 100644
--- a/fs/xfs/xfs_super.h
+++ b/fs/xfs/xfs_super.h
@@ -75,6 +75,8 @@ struct block_device;
 extern __uint64_t xfs_max_file_offset(unsigned int);
 
 extern void xfs_blkdev_issue_flush(struct xfs_buftarg *);
+extern xfs_agnumber_t xfs_set_inode32(struct xfs_mount *);
+extern xfs_agnumber_t xfs_set_inode64(struct xfs_mount *);
 
 extern const struct export_operations xfs_export_operations;
 extern const struct xattr_handler *xfs_xattr_handlers[];
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index e5795dd6013..7d36ccf57f9 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -37,6 +37,7 @@ struct xlog_recover;
 struct xlog_recover_item;
 struct xfs_buf_log_format;
 struct xfs_inode_log_format;
+struct xfs_bmbt_irec;
 
 DECLARE_EVENT_CLASS(xfs_attr_list_class,
 	TP_PROTO(struct xfs_attr_list_context *ctx),