[PATCH 14/49] xfs: introduce xfs_inode_buf.c for inode buffer operations

[Dave Chinner <david@fromorbit.com>]

From: Dave Chinner <dchinner@redhat.com>

The only thing remaining in xfs_inode.[ch] are the operations that
read, write or verify physical inodes in their underlying buffers.
Move all this code to xfs_inode_buf.[ch] and so we can stop sharing
xfs_inode.[ch] with userspace.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/Makefile        |   1 +
 fs/xfs/xfs_inode.c     | 413 ---------------------------------------------
 fs/xfs/xfs_inode.h     |  41 +----
 fs/xfs/xfs_inode_buf.c | 444 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/xfs_inode_buf.h |  53 ++++++
 5 files changed, 505 insertions(+), 447 deletions(-)
 create mode 100644 fs/xfs/xfs_inode_buf.c
 create mode 100644 fs/xfs/xfs_inode_buf.h

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index ce0b87e..7f2319d 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -75,6 +75,7 @@ xfs-y				+= xfs_alloc.o \
 				   xfs_icreate_item.o \
 				   xfs_inode.o \
 				   xfs_inode_fork.o \
+				   xfs_inode_buf.o \
 				   xfs_log_recover.o \
 				   xfs_mount.o \
 				   xfs_symlink.o \
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 51e4eb2..cf35d86 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -322,234 +322,6 @@ __xfs_iflock(
 	finish_wait(wq, &wait.wait);
 }
 
-/*
- * Check that none of the inode's in the buffer have a next
- * unlinked field of 0.
- */
-#if defined(DEBUG)
-void
-xfs_inobp_check(
-	xfs_mount_t	*mp,
-	xfs_buf_t	*bp)
-{
-	int		i;
-	int		j;
-	xfs_dinode_t	*dip;
-
-	j = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
-
-	for (i = 0; i < j; i++) {
-		dip = (xfs_dinode_t *)xfs_buf_offset(bp,
-					i * mp->m_sb.sb_inodesize);
-		if (!dip->di_next_unlinked)  {
-			xfs_alert(mp,
-	"Detected bogus zero next_unlinked field in incore inode buffer 0x%p.",
-				bp);
-			ASSERT(dip->di_next_unlinked);
-		}
-	}
-}
-#endif
-
-static void
-xfs_inode_buf_verify(
-	struct xfs_buf	*bp)
-{
-	struct xfs_mount *mp = bp->b_target->bt_mount;
-	int		i;
-	int		ni;
-
-	/*
-	 * Validate the magic number and version of every inode in the buffer
-	 */
-	ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock;
-	for (i = 0; i < ni; i++) {
-		int		di_ok;
-		xfs_dinode_t	*dip;
-
-		dip = (struct xfs_dinode *)xfs_buf_offset(bp,
-					(i << mp->m_sb.sb_inodelog));
-		di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
-			    XFS_DINODE_GOOD_VERSION(dip->di_version);
-		if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
-						XFS_ERRTAG_ITOBP_INOTOBP,
-						XFS_RANDOM_ITOBP_INOTOBP))) {
-			xfs_buf_ioerror(bp, EFSCORRUPTED);
-			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH,
-					     mp, dip);
-#ifdef DEBUG
-			xfs_emerg(mp,
-				"bad inode magic/vsn daddr %lld #%d (magic=%x)",
-				(unsigned long long)bp->b_bn, i,
-				be16_to_cpu(dip->di_magic));
-			ASSERT(0);
-#endif
-		}
-	}
-	xfs_inobp_check(mp, bp);
-}
-
-
-static void
-xfs_inode_buf_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_inode_buf_verify(bp);
-}
-
-static void
-xfs_inode_buf_write_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_inode_buf_verify(bp);
-}
-
-const struct xfs_buf_ops xfs_inode_buf_ops = {
-	.verify_read = xfs_inode_buf_read_verify,
-	.verify_write = xfs_inode_buf_write_verify,
-};
-
-
-/*
- * This routine is called to map an inode to the buffer containing the on-disk
- * version of the inode.  It returns a pointer to the buffer containing the
- * on-disk inode in the bpp parameter, and in the dipp parameter it returns a
- * pointer to the on-disk inode within that buffer.
- *
- * If a non-zero error is returned, then the contents of bpp and dipp are
- * undefined.
- */
-int
-xfs_imap_to_bp(
-	struct xfs_mount	*mp,
-	struct xfs_trans	*tp,
-	struct xfs_imap		*imap,
-	struct xfs_dinode       **dipp,
-	struct xfs_buf		**bpp,
-	uint			buf_flags,
-	uint			iget_flags)
-{
-	struct xfs_buf		*bp;
-	int			error;
-
-	buf_flags |= XBF_UNMAPPED;
-	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
-				   (int)imap->im_len, buf_flags, &bp,
-				   &xfs_inode_buf_ops);
-	if (error) {
-		if (error == EAGAIN) {
-			ASSERT(buf_flags & XBF_TRYLOCK);
-			return error;
-		}
-
-		if (error == EFSCORRUPTED &&
-		    (iget_flags & XFS_IGET_UNTRUSTED))
-			return XFS_ERROR(EINVAL);
-
-		xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
-			__func__, error);
-		return error;
-	}
-
-	*bpp = bp;
-	*dipp = (struct xfs_dinode *)xfs_buf_offset(bp, imap->im_boffset);
-	return 0;
-}
-
-STATIC void
-xfs_dinode_from_disk(
-	xfs_icdinode_t		*to,
-	xfs_dinode_t		*from)
-{
-	to->di_magic = be16_to_cpu(from->di_magic);
-	to->di_mode = be16_to_cpu(from->di_mode);
-	to->di_version = from ->di_version;
-	to->di_format = from->di_format;
-	to->di_onlink = be16_to_cpu(from->di_onlink);
-	to->di_uid = be32_to_cpu(from->di_uid);
-	to->di_gid = be32_to_cpu(from->di_gid);
-	to->di_nlink = be32_to_cpu(from->di_nlink);
-	to->di_projid_lo = be16_to_cpu(from->di_projid_lo);
-	to->di_projid_hi = be16_to_cpu(from->di_projid_hi);
-	memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
-	to->di_flushiter = be16_to_cpu(from->di_flushiter);
-	to->di_atime.t_sec = be32_to_cpu(from->di_atime.t_sec);
-	to->di_atime.t_nsec = be32_to_cpu(from->di_atime.t_nsec);
-	to->di_mtime.t_sec = be32_to_cpu(from->di_mtime.t_sec);
-	to->di_mtime.t_nsec = be32_to_cpu(from->di_mtime.t_nsec);
-	to->di_ctime.t_sec = be32_to_cpu(from->di_ctime.t_sec);
-	to->di_ctime.t_nsec = be32_to_cpu(from->di_ctime.t_nsec);
-	to->di_size = be64_to_cpu(from->di_size);
-	to->di_nblocks = be64_to_cpu(from->di_nblocks);
-	to->di_extsize = be32_to_cpu(from->di_extsize);
-	to->di_nextents = be32_to_cpu(from->di_nextents);
-	to->di_anextents = be16_to_cpu(from->di_anextents);
-	to->di_forkoff = from->di_forkoff;
-	to->di_aformat	= from->di_aformat;
-	to->di_dmevmask	= be32_to_cpu(from->di_dmevmask);
-	to->di_dmstate	= be16_to_cpu(from->di_dmstate);
-	to->di_flags	= be16_to_cpu(from->di_flags);
-	to->di_gen	= be32_to_cpu(from->di_gen);
-
-	if (to->di_version == 3) {
-		to->di_changecount = be64_to_cpu(from->di_changecount);
-		to->di_crtime.t_sec = be32_to_cpu(from->di_crtime.t_sec);
-		to->di_crtime.t_nsec = be32_to_cpu(from->di_crtime.t_nsec);
-		to->di_flags2 = be64_to_cpu(from->di_flags2);
-		to->di_ino = be64_to_cpu(from->di_ino);
-		to->di_lsn = be64_to_cpu(from->di_lsn);
-		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
-		uuid_copy(&to->di_uuid, &from->di_uuid);
-	}
-}
-
-void
-xfs_dinode_to_disk(
-	xfs_dinode_t		*to,
-	xfs_icdinode_t		*from)
-{
-	to->di_magic = cpu_to_be16(from->di_magic);
-	to->di_mode = cpu_to_be16(from->di_mode);
-	to->di_version = from ->di_version;
-	to->di_format = from->di_format;
-	to->di_onlink = cpu_to_be16(from->di_onlink);
-	to->di_uid = cpu_to_be32(from->di_uid);
-	to->di_gid = cpu_to_be32(from->di_gid);
-	to->di_nlink = cpu_to_be32(from->di_nlink);
-	to->di_projid_lo = cpu_to_be16(from->di_projid_lo);
-	to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
-	memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
-	to->di_flushiter = cpu_to_be16(from->di_flushiter);
-	to->di_atime.t_sec = cpu_to_be32(from->di_atime.t_sec);
-	to->di_atime.t_nsec = cpu_to_be32(from->di_atime.t_nsec);
-	to->di_mtime.t_sec = cpu_to_be32(from->di_mtime.t_sec);
-	to->di_mtime.t_nsec = cpu_to_be32(from->di_mtime.t_nsec);
-	to->di_ctime.t_sec = cpu_to_be32(from->di_ctime.t_sec);
-	to->di_ctime.t_nsec = cpu_to_be32(from->di_ctime.t_nsec);
-	to->di_size = cpu_to_be64(from->di_size);
-	to->di_nblocks = cpu_to_be64(from->di_nblocks);
-	to->di_extsize = cpu_to_be32(from->di_extsize);
-	to->di_nextents = cpu_to_be32(from->di_nextents);
-	to->di_anextents = cpu_to_be16(from->di_anextents);
-	to->di_forkoff = from->di_forkoff;
-	to->di_aformat = from->di_aformat;
-	to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
-	to->di_dmstate = cpu_to_be16(from->di_dmstate);
-	to->di_flags = cpu_to_be16(from->di_flags);
-	to->di_gen = cpu_to_be32(from->di_gen);
-
-	if (from->di_version == 3) {
-		to->di_changecount = cpu_to_be64(from->di_changecount);
-		to->di_crtime.t_sec = cpu_to_be32(from->di_crtime.t_sec);
-		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.t_nsec);
-		to->di_flags2 = cpu_to_be64(from->di_flags2);
-		to->di_ino = cpu_to_be64(from->di_ino);
-		to->di_lsn = cpu_to_be64(from->di_lsn);
-		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
-		uuid_copy(&to->di_uuid, &from->di_uuid);
-	}
-}
-
 STATIC uint
 _xfs_dic2xflags(
 	__uint16_t		di_flags)
@@ -608,191 +380,6 @@ xfs_dic2xflags(
 				(XFS_DFORK_Q(dip) ? XFS_XFLAG_HASATTR : 0);
 }
 
-static bool
-xfs_dinode_verify(
-	struct xfs_mount	*mp,
-	struct xfs_inode	*ip,
-	struct xfs_dinode	*dip)
-{
-	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
-		return false;
-
-	/* only version 3 or greater inodes are extensively verified here */
-	if (dip->di_version < 3)
-		return true;
-
-	if (!xfs_sb_version_hascrc(&mp->m_sb))
-		return false;
-	if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
-			      offsetof(struct xfs_dinode, di_crc)))
-		return false;
-	if (be64_to_cpu(dip->di_ino) != ip->i_ino)
-		return false;
-	if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_uuid))
-		return false;
-	return true;
-}
-
-void
-xfs_dinode_calc_crc(
-	struct xfs_mount	*mp,
-	struct xfs_dinode	*dip)
-{
-	__uint32_t		crc;
-
-	if (dip->di_version < 3)
-		return;
-
-	ASSERT(xfs_sb_version_hascrc(&mp->m_sb));
-	crc = xfs_start_cksum((char *)dip, mp->m_sb.sb_inodesize,
-			      offsetof(struct xfs_dinode, di_crc));
-	dip->di_crc = xfs_end_cksum(crc);
-}
-
-/*
- * Read the disk inode attributes into the in-core inode structure.
- *
- * If we are initialising a new inode and we are not utilising the
- * XFS_MOUNT_IKEEP inode cluster mode, we can simple build the new inode core
- * with a random generation number. If we are keeping inodes around, we need to
- * read the inode cluster to get the existing generation number off disk.
- */
-int
-xfs_iread(
-	xfs_mount_t	*mp,
-	xfs_trans_t	*tp,
-	xfs_inode_t	*ip,
-	uint		iget_flags)
-{
-	xfs_buf_t	*bp;
-	xfs_dinode_t	*dip;
-	int		error;
-
-	/*
-	 * Fill in the location information in the in-core inode.
-	 */
-	error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, iget_flags);
-	if (error)
-		return error;
-
-	/* shortcut IO on inode allocation if possible */
-	if ((iget_flags & XFS_IGET_CREATE) &&
-	    !(mp->m_flags & XFS_MOUNT_IKEEP)) {
-		/* initialise the on-disk inode core */
-		memset(&ip->i_d, 0, sizeof(ip->i_d));
-		ip->i_d.di_magic = XFS_DINODE_MAGIC;
-		ip->i_d.di_gen = prandom_u32();
-		if (xfs_sb_version_hascrc(&mp->m_sb)) {
-			ip->i_d.di_version = 3;
-			ip->i_d.di_ino = ip->i_ino;
-			uuid_copy(&ip->i_d.di_uuid, &mp->m_sb.sb_uuid);
-		} else
-			ip->i_d.di_version = 2;
-		return 0;
-	}
-
-	/*
-	 * Get pointers to the on-disk inode and the buffer containing it.
-	 */
-	error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0, iget_flags);
-	if (error)
-		return error;
-
-	/* even unallocated inodes are verified */
-	if (!xfs_dinode_verify(mp, ip, dip)) {
-		xfs_alert(mp, "%s: validation failed for inode %lld failed",
-				__func__, ip->i_ino);
-
-		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, dip);
-		error = XFS_ERROR(EFSCORRUPTED);
-		goto out_brelse;
-	}
-
-	/*
-	 * If the on-disk inode is already linked to a directory
-	 * entry, copy all of the inode into the in-core inode.
-	 * xfs_iformat_fork() handles copying in the inode format
-	 * specific information.
-	 * Otherwise, just get the truly permanent information.
-	 */
-	if (dip->di_mode) {
-		xfs_dinode_from_disk(&ip->i_d, dip);
-		error = xfs_iformat_fork(ip, dip);
-		if (error)  {
-#ifdef DEBUG
-			xfs_alert(mp, "%s: xfs_iformat() returned error %d",
-				__func__, error);
-#endif /* DEBUG */
-			goto out_brelse;
-		}
-	} else {
-		/*
-		 * Partial initialisation of the in-core inode. Just the bits
-		 * that xfs_ialloc won't overwrite or relies on being correct.
-		 */
-		ip->i_d.di_magic = be16_to_cpu(dip->di_magic);
-		ip->i_d.di_version = dip->di_version;
-		ip->i_d.di_gen = be32_to_cpu(dip->di_gen);
-		ip->i_d.di_flushiter = be16_to_cpu(dip->di_flushiter);
-
-		if (dip->di_version == 3) {
-			ip->i_d.di_ino = be64_to_cpu(dip->di_ino);
-			uuid_copy(&ip->i_d.di_uuid, &dip->di_uuid);
-		}
-
-		/*
-		 * Make sure to pull in the mode here as well in
-		 * case the inode is released without being used.
-		 * This ensures that xfs_inactive() will see that
-		 * the inode is already free and not try to mess
-		 * with the uninitialized part of it.
-		 */
-		ip->i_d.di_mode = 0;
-	}
-
-	/*
-	 * The inode format changed when we moved the link count and
-	 * made it 32 bits long.  If this is an old format inode,
-	 * convert it in memory to look like a new one.  If it gets
-	 * flushed to disk we will convert back before flushing or
-	 * logging it.  We zero out the new projid field and the old link
-	 * count field.  We'll handle clearing the pad field (the remains
-	 * of the old uuid field) when we actually convert the inode to
-	 * the new format. We don't change the version number so that we
-	 * can distinguish this from a real new format inode.
-	 */
-	if (ip->i_d.di_version == 1) {
-		ip->i_d.di_nlink = ip->i_d.di_onlink;
-		ip->i_d.di_onlink = 0;
-		xfs_set_projid(ip, 0);
-	}
-
-	ip->i_delayed_blks = 0;
-
-	/*
-	 * Mark the buffer containing the inode as something to keep
-	 * around for a while.  This helps to keep recently accessed
-	 * meta-data in-core longer.
-	 */
-	xfs_buf_set_ref(bp, XFS_INO_REF);
-
-	/*
-	 * Use xfs_trans_brelse() to release the buffer containing the on-disk
-	 * inode, because it was acquired with xfs_trans_read_buf() in
-	 * xfs_imap_to_bp() above.  If tp is NULL, this is just a normal
-	 * brelse().  If we're within a transaction, then xfs_trans_brelse()
-	 * will only release the buffer if it is not dirty within the
-	 * transaction.  It will be OK to release the buffer in this case,
-	 * because inodes on disk are never destroyed and we will be locking the
-	 * new in-core inode before putting it in the cache where other
-	 * processes can find it.  Thus we don't have to worry about the inode
-	 * being changed just because we released the buffer.
-	 */
- out_brelse:
-	xfs_trans_brelse(tp, bp);
-	return error;
-}
-
 /*
  * Allocate an inode on disk and return a copy of its in-core version.
  * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 0bd034a..8f775ed 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -18,24 +18,15 @@
 #ifndef	__XFS_INODE_H__
 #define	__XFS_INODE_H__
 
-struct posix_acl;
-struct xfs_dinode;
-struct xfs_inode;
-
+#include "xfs_inode_buf.h"
 #include "xfs_inode_fork.h"
 
 /*
- * Inode location information.  Stored in the inode and passed to
- * xfs_imap_to_bp() to get a buffer and dinode for a given inode.
+ * Kernel only inode definitions
  */
-struct xfs_imap {
-	xfs_daddr_t	im_blkno;	/* starting BB of inode chunk */
-	ushort		im_len;		/* length in BBs of inode chunk */
-	ushort		im_boffset;	/* inode offset in block in bytes */
-};
-
-#ifdef __KERNEL__
 
+struct xfs_dinode;
+struct xfs_inode;
 struct xfs_buf;
 struct xfs_bmap_free;
 struct xfs_bmbt_irec;
@@ -347,7 +338,10 @@ int		xfs_itruncate_extents(struct xfs_trans **, struct xfs_inode *,
 int		xfs_iunlink(struct xfs_trans *, xfs_inode_t *);
 
 void		xfs_iext_realloc(xfs_inode_t *, int, int);
+
 void		xfs_iunpin_wait(xfs_inode_t *);
+#define xfs_ipincount(ip)	((unsigned int) atomic_read(&ip->i_pincount))
+
 int		xfs_iflush(struct xfs_inode *, struct xfs_buf **);
 void		xfs_lock_inodes(xfs_inode_t **, int, uint);
 void		xfs_lock_two_inodes(xfs_inode_t *, xfs_inode_t *, uint);
@@ -367,27 +361,6 @@ do { \
 	iput(VFS_I(ip)); \
 } while (0)
 
-#endif /* __KERNEL__ */
-
-int		xfs_imap_to_bp(struct xfs_mount *, struct xfs_trans *,
-			       struct xfs_imap *, struct xfs_dinode **,
-			       struct xfs_buf **, uint, uint);
-int		xfs_iread(struct xfs_mount *, struct xfs_trans *,
-			  struct xfs_inode *, uint);
-void		xfs_dinode_calc_crc(struct xfs_mount *, struct xfs_dinode *);
-void		xfs_dinode_to_disk(struct xfs_dinode *,
-				   struct xfs_icdinode *);
-bool		xfs_can_free_eofblocks(struct xfs_inode *, bool);
-
-#define xfs_ipincount(ip)	((unsigned int) atomic_read(&ip->i_pincount))
-
-#if defined(DEBUG)
-void		xfs_inobp_check(struct xfs_mount *, struct xfs_buf *);
-#else
-#define	xfs_inobp_check(mp, bp)
-#endif /* DEBUG */
-
 extern struct kmem_zone	*xfs_inode_zone;
-extern const struct xfs_buf_ops xfs_inode_buf_ops;
 
 #endif	/* __XFS_INODE_H__ */
diff --git a/fs/xfs/xfs_inode_buf.c b/fs/xfs/xfs_inode_buf.c
new file mode 100644
index 0000000..4abbaf3
--- /dev/null
+++ b/fs/xfs/xfs_inode_buf.c
@@ -0,0 +1,444 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_error.h"
+#include "xfs_cksum.h"
+#include "xfs_icache.h"
+#include "xfs_ialloc.h"
+
+/*
+ * Check that none of the inode's in the buffer have a next
+ * unlinked field of 0.
+ */
+#if defined(DEBUG)
+void
+xfs_inobp_check(
+	xfs_mount_t	*mp,
+	xfs_buf_t	*bp)
+{
+	int		i;
+	int		j;
+	xfs_dinode_t	*dip;
+
+	j = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
+
+	for (i = 0; i < j; i++) {
+		dip = (xfs_dinode_t *)xfs_buf_offset(bp,
+					i * mp->m_sb.sb_inodesize);
+		if (!dip->di_next_unlinked)  {
+			xfs_alert(mp,
+	"Detected bogus zero next_unlinked field in incore inode buffer 0x%p.",
+				bp);
+			ASSERT(dip->di_next_unlinked);
+		}
+	}
+}
+#endif
+
+static void
+xfs_inode_buf_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	int		i;
+	int		ni;
+
+	/*
+	 * Validate the magic number and version of every inode in the buffer
+	 */
+	ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock;
+	for (i = 0; i < ni; i++) {
+		int		di_ok;
+		xfs_dinode_t	*dip;
+
+		dip = (struct xfs_dinode *)xfs_buf_offset(bp,
+					(i << mp->m_sb.sb_inodelog));
+		di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
+			    XFS_DINODE_GOOD_VERSION(dip->di_version);
+		if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
+						XFS_ERRTAG_ITOBP_INOTOBP,
+						XFS_RANDOM_ITOBP_INOTOBP))) {
+			xfs_buf_ioerror(bp, EFSCORRUPTED);
+			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH,
+					     mp, dip);
+#ifdef DEBUG
+			xfs_emerg(mp,
+				"bad inode magic/vsn daddr %lld #%d (magic=%x)",
+				(unsigned long long)bp->b_bn, i,
+				be16_to_cpu(dip->di_magic));
+			ASSERT(0);
+#endif
+		}
+	}
+	xfs_inobp_check(mp, bp);
+}
+
+static void
+xfs_inode_buf_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp);
+}
+
+static void
+xfs_inode_buf_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp);
+}
+
+const struct xfs_buf_ops xfs_inode_buf_ops = {
+	.verify_read = xfs_inode_buf_read_verify,
+	.verify_write = xfs_inode_buf_write_verify,
+};
+
+/*
+ * This routine is called to map an inode to the buffer containing the on-disk
+ * version of the inode.  It returns a pointer to the buffer containing the
+ * on-disk inode in the bpp parameter, and in the dipp parameter it returns a
+ * pointer to the on-disk inode within that buffer.
+ *
+ * If a non-zero error is returned, then the contents of bpp and dipp are
+ * undefined.
+ */
+int
+xfs_imap_to_bp(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	struct xfs_imap		*imap,
+	struct xfs_dinode       **dipp,
+	struct xfs_buf		**bpp,
+	uint			buf_flags,
+	uint			iget_flags)
+{
+	struct xfs_buf		*bp;
+	int			error;
+
+	buf_flags |= XBF_UNMAPPED;
+	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
+				   (int)imap->im_len, buf_flags, &bp,
+				   &xfs_inode_buf_ops);
+	if (error) {
+		if (error == EAGAIN) {
+			ASSERT(buf_flags & XBF_TRYLOCK);
+			return error;
+		}
+
+		if (error == EFSCORRUPTED &&
+		    (iget_flags & XFS_IGET_UNTRUSTED))
+			return XFS_ERROR(EINVAL);
+
+		xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
+			__func__, error);
+		return error;
+	}
+
+	*bpp = bp;
+	*dipp = (struct xfs_dinode *)xfs_buf_offset(bp, imap->im_boffset);
+	return 0;
+}
+
+STATIC void
+xfs_dinode_from_disk(
+	xfs_icdinode_t		*to,
+	xfs_dinode_t		*from)
+{
+	to->di_magic = be16_to_cpu(from->di_magic);
+	to->di_mode = be16_to_cpu(from->di_mode);
+	to->di_version = from ->di_version;
+	to->di_format = from->di_format;
+	to->di_onlink = be16_to_cpu(from->di_onlink);
+	to->di_uid = be32_to_cpu(from->di_uid);
+	to->di_gid = be32_to_cpu(from->di_gid);
+	to->di_nlink = be32_to_cpu(from->di_nlink);
+	to->di_projid_lo = be16_to_cpu(from->di_projid_lo);
+	to->di_projid_hi = be16_to_cpu(from->di_projid_hi);
+	memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
+	to->di_flushiter = be16_to_cpu(from->di_flushiter);
+	to->di_atime.t_sec = be32_to_cpu(from->di_atime.t_sec);
+	to->di_atime.t_nsec = be32_to_cpu(from->di_atime.t_nsec);
+	to->di_mtime.t_sec = be32_to_cpu(from->di_mtime.t_sec);
+	to->di_mtime.t_nsec = be32_to_cpu(from->di_mtime.t_nsec);
+	to->di_ctime.t_sec = be32_to_cpu(from->di_ctime.t_sec);
+	to->di_ctime.t_nsec = be32_to_cpu(from->di_ctime.t_nsec);
+	to->di_size = be64_to_cpu(from->di_size);
+	to->di_nblocks = be64_to_cpu(from->di_nblocks);
+	to->di_extsize = be32_to_cpu(from->di_extsize);
+	to->di_nextents = be32_to_cpu(from->di_nextents);
+	to->di_anextents = be16_to_cpu(from->di_anextents);
+	to->di_forkoff = from->di_forkoff;
+	to->di_aformat	= from->di_aformat;
+	to->di_dmevmask	= be32_to_cpu(from->di_dmevmask);
+	to->di_dmstate	= be16_to_cpu(from->di_dmstate);
+	to->di_flags	= be16_to_cpu(from->di_flags);
+	to->di_gen	= be32_to_cpu(from->di_gen);
+
+	if (to->di_version == 3) {
+		to->di_changecount = be64_to_cpu(from->di_changecount);
+		to->di_crtime.t_sec = be32_to_cpu(from->di_crtime.t_sec);
+		to->di_crtime.t_nsec = be32_to_cpu(from->di_crtime.t_nsec);
+		to->di_flags2 = be64_to_cpu(from->di_flags2);
+		to->di_ino = be64_to_cpu(from->di_ino);
+		to->di_lsn = be64_to_cpu(from->di_lsn);
+		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
+		uuid_copy(&to->di_uuid, &from->di_uuid);
+	}
+}
+
+void
+xfs_dinode_to_disk(
+	xfs_dinode_t		*to,
+	xfs_icdinode_t		*from)
+{
+	to->di_magic = cpu_to_be16(from->di_magic);
+	to->di_mode = cpu_to_be16(from->di_mode);
+	to->di_version = from ->di_version;
+	to->di_format = from->di_format;
+	to->di_onlink = cpu_to_be16(from->di_onlink);
+	to->di_uid = cpu_to_be32(from->di_uid);
+	to->di_gid = cpu_to_be32(from->di_gid);
+	to->di_nlink = cpu_to_be32(from->di_nlink);
+	to->di_projid_lo = cpu_to_be16(from->di_projid_lo);
+	to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
+	memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
+	to->di_flushiter = cpu_to_be16(from->di_flushiter);
+	to->di_atime.t_sec = cpu_to_be32(from->di_atime.t_sec);
+	to->di_atime.t_nsec = cpu_to_be32(from->di_atime.t_nsec);
+	to->di_mtime.t_sec = cpu_to_be32(from->di_mtime.t_sec);
+	to->di_mtime.t_nsec = cpu_to_be32(from->di_mtime.t_nsec);
+	to->di_ctime.t_sec = cpu_to_be32(from->di_ctime.t_sec);
+	to->di_ctime.t_nsec = cpu_to_be32(from->di_ctime.t_nsec);
+	to->di_size = cpu_to_be64(from->di_size);
+	to->di_nblocks = cpu_to_be64(from->di_nblocks);
+	to->di_extsize = cpu_to_be32(from->di_extsize);
+	to->di_nextents = cpu_to_be32(from->di_nextents);
+	to->di_anextents = cpu_to_be16(from->di_anextents);
+	to->di_forkoff = from->di_forkoff;
+	to->di_aformat = from->di_aformat;
+	to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
+	to->di_dmstate = cpu_to_be16(from->di_dmstate);
+	to->di_flags = cpu_to_be16(from->di_flags);
+	to->di_gen = cpu_to_be32(from->di_gen);
+
+	if (from->di_version == 3) {
+		to->di_changecount = cpu_to_be64(from->di_changecount);
+		to->di_crtime.t_sec = cpu_to_be32(from->di_crtime.t_sec);
+		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.t_nsec);
+		to->di_flags2 = cpu_to_be64(from->di_flags2);
+		to->di_ino = cpu_to_be64(from->di_ino);
+		to->di_lsn = cpu_to_be64(from->di_lsn);
+		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
+		uuid_copy(&to->di_uuid, &from->di_uuid);
+	}
+}
+
+static bool
+xfs_dinode_verify(
+	struct xfs_mount	*mp,
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*dip)
+{
+	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
+		return false;
+
+	/* only version 3 or greater inodes are extensively verified here */
+	if (dip->di_version < 3)
+		return true;
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return false;
+	if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
+			      offsetof(struct xfs_dinode, di_crc)))
+		return false;
+	if (be64_to_cpu(dip->di_ino) != ip->i_ino)
+		return false;
+	if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_uuid))
+		return false;
+	return true;
+}
+
+void
+xfs_dinode_calc_crc(
+	struct xfs_mount	*mp,
+	struct xfs_dinode	*dip)
+{
+	__uint32_t		crc;
+
+	if (dip->di_version < 3)
+		return;
+
+	ASSERT(xfs_sb_version_hascrc(&mp->m_sb));
+	crc = xfs_start_cksum((char *)dip, mp->m_sb.sb_inodesize,
+			      offsetof(struct xfs_dinode, di_crc));
+	dip->di_crc = xfs_end_cksum(crc);
+}
+
+/*
+ * Read the disk inode attributes into the in-core inode structure.
+ *
+ * If we are initialising a new inode and we are not utilising the
+ * XFS_MOUNT_IKEEP inode cluster mode, we can simple build the new inode core
+ * with a random generation number. If we are keeping inodes around, we need to
+ * read the inode cluster to get the existing generation number off disk.
+ */
+int
+xfs_iread(
+	xfs_mount_t	*mp,
+	xfs_trans_t	*tp,
+	xfs_inode_t	*ip,
+	uint		iget_flags)
+{
+	xfs_buf_t	*bp;
+	xfs_dinode_t	*dip;
+	int		error;
+
+	/*
+	 * Fill in the location information in the in-core inode.
+	 */
+	error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, iget_flags);
+	if (error)
+		return error;
+
+	/* shortcut IO on inode allocation if possible */
+	if ((iget_flags & XFS_IGET_CREATE) &&
+	    !(mp->m_flags & XFS_MOUNT_IKEEP)) {
+		/* initialise the on-disk inode core */
+		memset(&ip->i_d, 0, sizeof(ip->i_d));
+		ip->i_d.di_magic = XFS_DINODE_MAGIC;
+		ip->i_d.di_gen = prandom_u32();
+		if (xfs_sb_version_hascrc(&mp->m_sb)) {
+			ip->i_d.di_version = 3;
+			ip->i_d.di_ino = ip->i_ino;
+			uuid_copy(&ip->i_d.di_uuid, &mp->m_sb.sb_uuid);
+		} else
+			ip->i_d.di_version = 2;
+		return 0;
+	}
+
+	/*
+	 * Get pointers to the on-disk inode and the buffer containing it.
+	 */
+	error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0, iget_flags);
+	if (error)
+		return error;
+
+	/* even unallocated inodes are verified */
+	if (!xfs_dinode_verify(mp, ip, dip)) {
+		xfs_alert(mp, "%s: validation failed for inode %lld failed",
+				__func__, ip->i_ino);
+
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, dip);
+		error = XFS_ERROR(EFSCORRUPTED);
+		goto out_brelse;
+	}
+
+	/*
+	 * If the on-disk inode is already linked to a directory
+	 * entry, copy all of the inode into the in-core inode.
+	 * xfs_iformat_fork() handles copying in the inode format
+	 * specific information.
+	 * Otherwise, just get the truly permanent information.
+	 */
+	if (dip->di_mode) {
+		xfs_dinode_from_disk(&ip->i_d, dip);
+		error = xfs_iformat_fork(ip, dip);
+		if (error)  {
+#ifdef DEBUG
+			xfs_alert(mp, "%s: xfs_iformat() returned error %d",
+				__func__, error);
+#endif /* DEBUG */
+			goto out_brelse;
+		}
+	} else {
+		/*
+		 * Partial initialisation of the in-core inode. Just the bits
+		 * that xfs_ialloc won't overwrite or relies on being correct.
+		 */
+		ip->i_d.di_magic = be16_to_cpu(dip->di_magic);
+		ip->i_d.di_version = dip->di_version;
+		ip->i_d.di_gen = be32_to_cpu(dip->di_gen);
+		ip->i_d.di_flushiter = be16_to_cpu(dip->di_flushiter);
+
+		if (dip->di_version == 3) {
+			ip->i_d.di_ino = be64_to_cpu(dip->di_ino);
+			uuid_copy(&ip->i_d.di_uuid, &dip->di_uuid);
+		}
+
+		/*
+		 * Make sure to pull in the mode here as well in
+		 * case the inode is released without being used.
+		 * This ensures that xfs_inactive() will see that
+		 * the inode is already free and not try to mess
+		 * with the uninitialized part of it.
+		 */
+		ip->i_d.di_mode = 0;
+	}
+
+	/*
+	 * The inode format changed when we moved the link count and
+	 * made it 32 bits long.  If this is an old format inode,
+	 * convert it in memory to look like a new one.  If it gets
+	 * flushed to disk we will convert back before flushing or
+	 * logging it.  We zero out the new projid field and the old link
+	 * count field.  We'll handle clearing the pad field (the remains
+	 * of the old uuid field) when we actually convert the inode to
+	 * the new format. We don't change the version number so that we
+	 * can distinguish this from a real new format inode.
+	 */
+	if (ip->i_d.di_version == 1) {
+		ip->i_d.di_nlink = ip->i_d.di_onlink;
+		ip->i_d.di_onlink = 0;
+		xfs_set_projid(ip, 0);
+	}
+
+	ip->i_delayed_blks = 0;
+
+	/*
+	 * Mark the buffer containing the inode as something to keep
+	 * around for a while.  This helps to keep recently accessed
+	 * meta-data in-core longer.
+	 */
+	xfs_buf_set_ref(bp, XFS_INO_REF);
+
+	/*
+	 * Use xfs_trans_brelse() to release the buffer containing the on-disk
+	 * inode, because it was acquired with xfs_trans_read_buf() in
+	 * xfs_imap_to_bp() above.  If tp is NULL, this is just a normal
+	 * brelse().  If we're within a transaction, then xfs_trans_brelse()
+	 * will only release the buffer if it is not dirty within the
+	 * transaction.  It will be OK to release the buffer in this case,
+	 * because inodes on disk are never destroyed and we will be locking the
+	 * new in-core inode before putting it in the cache where other
+	 * processes can find it.  Thus we don't have to worry about the inode
+	 * being changed just because we released the buffer.
+	 */
+ out_brelse:
+	xfs_trans_brelse(tp, bp);
+	return error;
+}
diff --git a/fs/xfs/xfs_inode_buf.h b/fs/xfs/xfs_inode_buf.h
new file mode 100644
index 0000000..b5f1e22
--- /dev/null
+++ b/fs/xfs/xfs_inode_buf.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#ifndef	__XFS_INODE_BUF_H__
+#define	__XFS_INODE_BUF_H__
+
+struct xfs_inode;
+struct xfs_dinode;
+struct xfs_icdinode;
+
+/*
+ * Inode location information.  Stored in the inode and passed to
+ * xfs_imap_to_bp() to get a buffer and dinode for a given inode.
+ */
+struct xfs_imap {
+	xfs_daddr_t	im_blkno;	/* starting BB of inode chunk */
+	ushort		im_len;		/* length in BBs of inode chunk */
+	ushort		im_boffset;	/* inode offset in block in bytes */
+};
+
+int		xfs_imap_to_bp(struct xfs_mount *, struct xfs_trans *,
+			       struct xfs_imap *, struct xfs_dinode **,
+			       struct xfs_buf **, uint, uint);
+int		xfs_iread(struct xfs_mount *, struct xfs_trans *,
+			  struct xfs_inode *, uint);
+void		xfs_dinode_calc_crc(struct xfs_mount *, struct xfs_dinode *);
+void		xfs_dinode_to_disk(struct xfs_dinode *,
+				   struct xfs_icdinode *);
+bool		xfs_can_free_eofblocks(struct xfs_inode *, bool);
+
+#if defined(DEBUG)
+void		xfs_inobp_check(struct xfs_mount *, struct xfs_buf *);
+#else
+#define	xfs_inobp_check(mp, bp)
+#endif /* DEBUG */
+
+extern const struct xfs_buf_ops xfs_inode_buf_ops;
+
+#endif	/* __XFS_INODE_BUF_H__ */
-- 
1.8.3.2

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