1 files changed, 828 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
new file mode 100644
index 000000000..09d9c8cfa
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_cksum.h"
+#include "xfs_icache.h"
+#include "xfs_trans.h"
+#include "xfs_ialloc.h"
+#include "xfs_dir2.h"
+
+#include <linux/iversion.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_buf_offset(bp, i * mp->m_sb.sb_inodesize);
+		if (!dip->di_next_unlinked)  {
+			xfs_alert(mp,
+	"Detected bogus zero next_unlinked field in inode %d buffer 0x%llx.",
+				i, (long long)bp->b_bn);
+		}
+	}
+}
+#endif
+
+bool
+xfs_dinode_good_version(
+	struct xfs_mount *mp,
+	__u8		version)
+{
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		return version == 3;
+
+	return version == 1 || version == 2;
+}
+
+/*
+ * If we are doing readahead on an inode buffer, we might be in log recovery
+ * reading an inode allocation buffer that hasn't yet been replayed, and hence
+ * has not had the inode cores stamped into it. Hence for readahead, the buffer
+ * may be potentially invalid.
+ *
+ * If the readahead buffer is invalid, we need to mark it with an error and
+ * clear the DONE status of the buffer so that a followup read will re-read it
+ * from disk. We don't report the error otherwise to avoid warnings during log
+ * recovery and we don't get unnecssary panics on debug kernels. We use EIO here
+ * because all we want to do is say readahead failed; there is no-one to report
+ * the error to, so this will distinguish it from a non-ra verifier failure.
+ * Changes to this readahead error behavour also need to be reflected in
+ * xfs_dquot_buf_readahead_verify().
+ */
+static void
+xfs_inode_buf_verify(
+	struct xfs_buf	*bp,
+	bool		readahead)
+{
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	xfs_agnumber_t	agno;
+	int		i;
+	int		ni;
+
+	/*
+	 * Validate the magic number and version of every inode in the buffer
+	 */
+	agno = xfs_daddr_to_agno(mp, XFS_BUF_ADDR(bp));
+	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;
+		xfs_agino_t	unlinked_ino;
+
+		dip = xfs_buf_offset(bp, (i << mp->m_sb.sb_inodelog));
+		unlinked_ino = be32_to_cpu(dip->di_next_unlinked);
+		di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
+			xfs_dinode_good_version(mp, dip->di_version) &&
+			(unlinked_ino == NULLAGINO ||
+			 xfs_verify_agino(mp, agno, unlinked_ino));
+		if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
+						XFS_ERRTAG_ITOBP_INOTOBP))) {
+			if (readahead) {
+				bp->b_flags &= ~XBF_DONE;
+				xfs_buf_ioerror(bp, -EIO);
+				return;
+			}
+
+#ifdef DEBUG
+			xfs_alert(mp,
+				"bad inode magic/vsn daddr %lld #%d (magic=%x)",
+				(unsigned long long)bp->b_bn, i,
+				be16_to_cpu(dip->di_magic));
+#endif
+			xfs_buf_verifier_error(bp, -EFSCORRUPTED,
+					__func__, dip, sizeof(*dip),
+					NULL);
+			return;
+		}
+	}
+}
+
+
+static void
+xfs_inode_buf_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, false);
+}
+
+static void
+xfs_inode_buf_readahead_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, true);
+}
+
+static void
+xfs_inode_buf_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, false);
+}
+
+const struct xfs_buf_ops xfs_inode_buf_ops = {
+	.name = "xfs_inode",
+	.verify_read = xfs_inode_buf_read_verify,
+	.verify_write = xfs_inode_buf_write_verify,
+};
+
+const struct xfs_buf_ops xfs_inode_buf_ra_ops = {
+	.name = "xxfs_inode_ra",
+	.verify_read = xfs_inode_buf_readahead_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;
+		}
+		xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
+			__func__, error);
+		return error;
+	}
+
+	*bpp = bp;
+	*dipp = xfs_buf_offset(bp, imap->im_boffset);
+	return 0;
+}
+
+void
+xfs_inode_from_disk(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*from)
+{
+	struct xfs_icdinode	*to = &ip->i_d;
+	struct inode		*inode = VFS_I(ip);
+
+
+	/*
+	 * Convert v1 inodes immediately to v2 inode format as this is the
+	 * minimum inode version format we support in the rest of the code.
+	 */
+	to->di_version = from->di_version;
+	if (to->di_version == 1) {
+		set_nlink(inode, be16_to_cpu(from->di_onlink));
+		to->di_projid_lo = 0;
+		to->di_projid_hi = 0;
+		to->di_version = 2;
+	} else {
+		set_nlink(inode, 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);
+	}
+
+	to->di_format = from->di_format;
+	to->di_uid = be32_to_cpu(from->di_uid);
+	to->di_gid = be32_to_cpu(from->di_gid);
+	to->di_flushiter = be16_to_cpu(from->di_flushiter);
+
+	/*
+	 * Time is signed, so need to convert to signed 32 bit before
+	 * storing in inode timestamp which may be 64 bit. Otherwise
+	 * a time before epoch is converted to a time long after epoch
+	 * on 64 bit systems.
+	 */
+	inode->i_atime.tv_sec = (int)be32_to_cpu(from->di_atime.t_sec);
+	inode->i_atime.tv_nsec = (int)be32_to_cpu(from->di_atime.t_nsec);
+	inode->i_mtime.tv_sec = (int)be32_to_cpu(from->di_mtime.t_sec);
+	inode->i_mtime.tv_nsec = (int)be32_to_cpu(from->di_mtime.t_nsec);
+	inode->i_ctime.tv_sec = (int)be32_to_cpu(from->di_ctime.t_sec);
+	inode->i_ctime.tv_nsec = (int)be32_to_cpu(from->di_ctime.t_nsec);
+	inode->i_generation = be32_to_cpu(from->di_gen);
+	inode->i_mode = be16_to_cpu(from->di_mode);
+
+	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);
+
+	if (to->di_version == 3) {
+		inode_set_iversion_queried(inode,
+					   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_cowextsize = be32_to_cpu(from->di_cowextsize);
+	}
+}
+
+void
+xfs_inode_to_disk(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*to,
+	xfs_lsn_t		lsn)
+{
+	struct xfs_icdinode	*from = &ip->i_d;
+	struct inode		*inode = VFS_I(ip);
+
+	to->di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
+	to->di_onlink = 0;
+
+	to->di_version = from->di_version;
+	to->di_format = from->di_format;
+	to->di_uid = cpu_to_be32(from->di_uid);
+	to->di_gid = cpu_to_be32(from->di_gid);
+	to->di_projid_lo = cpu_to_be16(from->di_projid_lo);
+	to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
+
+	memset(to->di_pad, 0, sizeof(to->di_pad));
+	to->di_atime.t_sec = cpu_to_be32(inode->i_atime.tv_sec);
+	to->di_atime.t_nsec = cpu_to_be32(inode->i_atime.tv_nsec);
+	to->di_mtime.t_sec = cpu_to_be32(inode->i_mtime.tv_sec);
+	to->di_mtime.t_nsec = cpu_to_be32(inode->i_mtime.tv_nsec);
+	to->di_ctime.t_sec = cpu_to_be32(inode->i_ctime.tv_sec);
+	to->di_ctime.t_nsec = cpu_to_be32(inode->i_ctime.tv_nsec);
+	to->di_nlink = cpu_to_be32(inode->i_nlink);
+	to->di_gen = cpu_to_be32(inode->i_generation);
+	to->di_mode = cpu_to_be16(inode->i_mode);
+
+	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);
+
+	if (from->di_version == 3) {
+		to->di_changecount = cpu_to_be64(inode_peek_iversion(inode));
+		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_cowextsize = cpu_to_be32(from->di_cowextsize);
+		to->di_ino = cpu_to_be64(ip->i_ino);
+		to->di_lsn = cpu_to_be64(lsn);
+		memset(to->di_pad2, 0, sizeof(to->di_pad2));
+		uuid_copy(&to->di_uuid, &ip->i_mount->m_sb.sb_meta_uuid);
+		to->di_flushiter = 0;
+	} else {
+		to->di_flushiter = cpu_to_be16(from->di_flushiter);
+	}
+}
+
+void
+xfs_log_dinode_to_disk(
+	struct xfs_log_dinode	*from,
+	struct xfs_dinode	*to)
+{
+	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 = 0;
+	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_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_cowextsize = cpu_to_be32(from->di_cowextsize);
+		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);
+		to->di_flushiter = 0;
+	} else {
+		to->di_flushiter = cpu_to_be16(from->di_flushiter);
+	}
+}
+
+static xfs_failaddr_t
+xfs_dinode_verify_fork(
+	struct xfs_dinode	*dip,
+	struct xfs_mount	*mp,
+	int			whichfork)
+{
+	uint32_t		di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
+
+	switch (XFS_DFORK_FORMAT(dip, whichfork)) {
+	case XFS_DINODE_FMT_LOCAL:
+		/*
+		 * no local regular files yet
+		 */
+		if (whichfork == XFS_DATA_FORK) {
+			if (S_ISREG(be16_to_cpu(dip->di_mode)))
+				return __this_address;
+			if (be64_to_cpu(dip->di_size) >
+					XFS_DFORK_SIZE(dip, mp, whichfork))
+				return __this_address;
+		}
+		if (di_nextents)
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_EXTENTS:
+		if (di_nextents > XFS_DFORK_MAXEXT(dip, mp, whichfork))
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		if (whichfork == XFS_ATTR_FORK) {
+			if (di_nextents > MAXAEXTNUM)
+				return __this_address;
+		} else if (di_nextents > MAXEXTNUM) {
+			return __this_address;
+		}
+		break;
+	default:
+		return __this_address;
+	}
+	return NULL;
+}
+
+static xfs_failaddr_t
+xfs_dinode_verify_forkoff(
+	struct xfs_dinode	*dip,
+	struct xfs_mount	*mp)
+{
+	if (!XFS_DFORK_Q(dip))
+		return NULL;
+
+	switch (dip->di_format)  {
+	case XFS_DINODE_FMT_DEV:
+		if (dip->di_forkoff != (roundup(sizeof(xfs_dev_t), 8) >> 3))
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_LOCAL:	/* fall through ... */
+	case XFS_DINODE_FMT_EXTENTS:    /* fall through ... */
+	case XFS_DINODE_FMT_BTREE:
+		if (dip->di_forkoff >= (XFS_LITINO(mp, dip->di_version) >> 3))
+			return __this_address;
+		break;
+	default:
+		return __this_address;
+	}
+	return NULL;
+}
+
+xfs_failaddr_t
+xfs_dinode_verify(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino,
+	struct xfs_dinode	*dip)
+{
+	xfs_failaddr_t		fa;
+	uint16_t		mode;
+	uint16_t		flags;
+	uint64_t		flags2;
+	uint64_t		di_size;
+
+	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
+		return __this_address;
+
+	/* Verify v3 integrity information first */
+	if (dip->di_version >= 3) {
+		if (!xfs_sb_version_hascrc(&mp->m_sb))
+			return __this_address;
+		if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
+				      XFS_DINODE_CRC_OFF))
+			return __this_address;
+		if (be64_to_cpu(dip->di_ino) != ino)
+			return __this_address;
+		if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+	}
+
+	/* don't allow invalid i_size */
+	di_size = be64_to_cpu(dip->di_size);
+	if (di_size & (1ULL << 63))
+		return __this_address;
+
+	mode = be16_to_cpu(dip->di_mode);
+	if (mode && xfs_mode_to_ftype(mode) == XFS_DIR3_FT_UNKNOWN)
+		return __this_address;
+
+	/* No zero-length symlinks/dirs. */
+	if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0)
+		return __this_address;
+
+	/* Fork checks carried over from xfs_iformat_fork */
+	if (mode &&
+	    be32_to_cpu(dip->di_nextents) + be16_to_cpu(dip->di_anextents) >
+			be64_to_cpu(dip->di_nblocks))
+		return __this_address;
+
+	if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize)
+		return __this_address;
+
+	flags = be16_to_cpu(dip->di_flags);
+
+	if (mode && (flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp)
+		return __this_address;
+
+	/* check for illegal values of forkoff */
+	fa = xfs_dinode_verify_forkoff(dip, mp);
+	if (fa)
+		return fa;
+
+	/* Do we have appropriate data fork formats for the mode? */
+	switch (mode & S_IFMT) {
+	case S_IFIFO:
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFSOCK:
+		if (dip->di_format != XFS_DINODE_FMT_DEV)
+			return __this_address;
+		break;
+	case S_IFREG:
+	case S_IFLNK:
+	case S_IFDIR:
+		fa = xfs_dinode_verify_fork(dip, mp, XFS_DATA_FORK);
+		if (fa)
+			return fa;
+		break;
+	case 0:
+		/* Uninitialized inode ok. */
+		break;
+	default:
+		return __this_address;
+	}
+
+	if (XFS_DFORK_Q(dip)) {
+		fa = xfs_dinode_verify_fork(dip, mp, XFS_ATTR_FORK);
+		if (fa)
+			return fa;
+	} else {
+		/*
+		 * If there is no fork offset, this may be a freshly-made inode
+		 * in a new disk cluster, in which case di_aformat is zeroed.
+		 * Otherwise, such an inode must be in EXTENTS format; this goes
+		 * for freed inodes as well.
+		 */
+		switch (dip->di_aformat) {
+		case 0:
+		case XFS_DINODE_FMT_EXTENTS:
+			break;
+		default:
+			return __this_address;
+		}
+		if (dip->di_anextents)
+			return __this_address;
+	}
+
+	/* extent size hint validation */
+	fa = xfs_inode_validate_extsize(mp, be32_to_cpu(dip->di_extsize),
+			mode, flags);
+	if (fa)
+		return fa;
+
+	/* only version 3 or greater inodes are extensively verified here */
+	if (dip->di_version < 3)
+		return NULL;
+
+	flags2 = be64_to_cpu(dip->di_flags2);
+
+	/* don't allow reflink/cowextsize if we don't have reflink */
+	if ((flags2 & (XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)) &&
+	     !xfs_sb_version_hasreflink(&mp->m_sb))
+		return __this_address;
+
+	/* only regular files get reflink */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && (mode & S_IFMT) != S_IFREG)
+		return __this_address;
+
+	/* don't let reflink and realtime mix */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
+		return __this_address;
+
+	/* don't let reflink and dax mix */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
+		return __this_address;
+
+	/* COW extent size hint validation */
+	fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),
+			mode, flags, flags2);
+	if (fa)
+		return fa;
+
+	return NULL;
+}
+
+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_update((char *)dip, mp->m_sb.sb_inodesize,
+			      XFS_DINODE_CRC_OFF);
+	dip->di_crc = xfs_end_cksum(crc);
+}
+
+/*
+ * Read the disk inode attributes into the in-core inode structure.
+ *
+ * For version 5 superblocks, 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. Further, if we are using version 4 superblocks (i.e. v1/v2 inode
+ * format) then log recovery is dependent on the di_flushiter field being
+ * initialised from the current on-disk value and hence we must also read the
+ * inode 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;
+	xfs_failaddr_t	fa;
+	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) &&
+	    xfs_sb_version_hascrc(&mp->m_sb) &&
+	    !(mp->m_flags & XFS_MOUNT_IKEEP)) {
+		/* initialise the on-disk inode core */
+		memset(&ip->i_d, 0, sizeof(ip->i_d));
+		VFS_I(ip)->i_generation = prandom_u32();
+		ip->i_d.di_version = 3;
+		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 */
+	fa = xfs_dinode_verify(mp, ip->i_ino, dip);
+	if (fa) {
+		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "dinode", dip,
+				sizeof(*dip), fa);
+		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_inode_from_disk(ip, 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_version = dip->di_version;
+		VFS_I(ip)->i_generation = be32_to_cpu(dip->di_gen);
+		ip->i_d.di_flushiter = be16_to_cpu(dip->di_flushiter);
+
+		/*
+		 * 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.
+		 */
+		VFS_I(ip)->i_mode = 0;
+	}
+
+	ASSERT(ip->i_d.di_version >= 2);
+	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;
+}
+
+/*
+ * Validate di_extsize hint.
+ *
+ * The rules are documented at xfs_ioctl_setattr_check_extsize().
+ * These functions must be kept in sync with each other.
+ */
+xfs_failaddr_t
+xfs_inode_validate_extsize(
+	struct xfs_mount		*mp,
+	uint32_t			extsize,
+	uint16_t			mode,
+	uint16_t			flags)
+{
+	bool				rt_flag;
+	bool				hint_flag;
+	bool				inherit_flag;
+	uint32_t			extsize_bytes;
+	uint32_t			blocksize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags & XFS_DIFLAG_EXTSIZE);
+	inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT);
+	extsize_bytes = XFS_FSB_TO_B(mp, extsize);
+
+	if (rt_flag)
+		blocksize_bytes = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog;
+	else
+		blocksize_bytes = mp->m_sb.sb_blocksize;
+
+	if ((hint_flag || inherit_flag) && !(S_ISDIR(mode) || S_ISREG(mode)))
+		return __this_address;
+
+	if (hint_flag && !S_ISREG(mode))
+		return __this_address;
+
+	if (inherit_flag && !S_ISDIR(mode))
+		return __this_address;
+
+	if ((hint_flag || inherit_flag) && extsize == 0)
+		return __this_address;
+
+	/* free inodes get flags set to zero but extsize remains */
+	if (mode && !(hint_flag || inherit_flag) && extsize != 0)
+		return __this_address;
+
+	if (extsize_bytes % blocksize_bytes)
+		return __this_address;
+
+	if (extsize > MAXEXTLEN)
+		return __this_address;
+
+	if (!rt_flag && extsize > mp->m_sb.sb_agblocks / 2)
+		return __this_address;
+
+	return NULL;
+}
+
+/*
+ * Validate di_cowextsize hint.
+ *
+ * The rules are documented at xfs_ioctl_setattr_check_cowextsize().
+ * These functions must be kept in sync with each other.
+ */
+xfs_failaddr_t
+xfs_inode_validate_cowextsize(
+	struct xfs_mount		*mp,
+	uint32_t			cowextsize,
+	uint16_t			mode,
+	uint16_t			flags,
+	uint64_t			flags2)
+{
+	bool				rt_flag;
+	bool				hint_flag;
+	uint32_t			cowextsize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE);
+	cowextsize_bytes = XFS_FSB_TO_B(mp, cowextsize);
+
+	if (hint_flag && !xfs_sb_version_hasreflink(&mp->m_sb))
+		return __this_address;
+
+	if (hint_flag && !(S_ISDIR(mode) || S_ISREG(mode)))
+		return __this_address;
+
+	if (hint_flag && cowextsize == 0)
+		return __this_address;
+
+	/* free inodes get flags set to zero but cowextsize remains */
+	if (mode && !hint_flag && cowextsize != 0)
+		return __this_address;
+
+	if (hint_flag && rt_flag)
+		return __this_address;
+
+	if (cowextsize_bytes % mp->m_sb.sb_blocksize)
+		return __this_address;
+
+	if (cowextsize > MAXEXTLEN)
+		return __this_address;
+
+	if (cowextsize > mp->m_sb.sb_agblocks / 2)
+		return __this_address;
+
+	return NULL;
+}