Given the following code containing errors, provide Common Weakness Enumeration (CWE) identifiers and corresponding messages in JSON format. Each identified weakness should have a unique entry in the JSON array.
    Code: xfs_iflush_int(
	struct xfs_inode	*ip,
	struct xfs_buf		*bp)
{
	struct xfs_inode_log_item *iip = ip->i_itemp;
	struct xfs_dinode	*dip;
	struct xfs_mount	*mp = ip->i_mount;

	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
	ASSERT(xfs_isiflocked(ip));
	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
	ASSERT(iip != NULL && iip->ili_fields != 0);
	ASSERT(ip->i_d.di_version > 1);

	/* set *dip = inode's place in the buffer */
	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);

	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
			       mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
			"%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",
			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
		goto corrupt_out;
	}
	if (XFS_TEST_ERROR(ip->i_d.di_magic != XFS_DINODE_MAGIC,
				mp, XFS_ERRTAG_IFLUSH_2, XFS_RANDOM_IFLUSH_2)) {
		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
			"%s: Bad inode %Lu, ptr 0x%p, magic number 0x%x",
			__func__, ip->i_ino, ip, ip->i_d.di_magic);
		goto corrupt_out;
	}
	if (S_ISREG(ip->i_d.di_mode)) {
		if (XFS_TEST_ERROR(
		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
		    mp, XFS_ERRTAG_IFLUSH_3, XFS_RANDOM_IFLUSH_3)) {
			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
				"%s: Bad regular inode %Lu, ptr 0x%p",
				__func__, ip->i_ino, ip);
			goto corrupt_out;
		}
	} else if (S_ISDIR(ip->i_d.di_mode)) {
		if (XFS_TEST_ERROR(
		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
		    mp, XFS_ERRTAG_IFLUSH_4, XFS_RANDOM_IFLUSH_4)) {
			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
				"%s: Bad directory inode %Lu, ptr 0x%p",
				__func__, ip->i_ino, ip);
			goto corrupt_out;
		}
	}
	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5,
				XFS_RANDOM_IFLUSH_5)) {
		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
			"%s: detected corrupt incore inode %Lu, "
			"total extents = %d, nblocks = %Ld, ptr 0x%p",
			__func__, ip->i_ino,
			ip->i_d.di_nextents + ip->i_d.di_anextents,
			ip->i_d.di_nblocks, ip);
		goto corrupt_out;
	}
	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
				mp, XFS_ERRTAG_IFLUSH_6, XFS_RANDOM_IFLUSH_6)) {
		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
			"%s: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
		goto corrupt_out;
	}

	/*
	 * Inode item log recovery for v2 inodes are dependent on the
	 * di_flushiter count for correct sequencing. We bump the flush
	 * iteration count so we can detect flushes which postdate a log record
	 * during recovery. This is redundant as we now log every change and
	 * hence this can't happen but we need to still do it to ensure
	 * backwards compatibility with old kernels that predate logging all
	 * inode changes.
	 */
	if (ip->i_d.di_version < 3)
		ip->i_d.di_flushiter++;

	/*
	 * Copy the dirty parts of the inode into the on-disk
	 * inode.  We always copy out the core of the inode,
	 * because if the inode is dirty at all the core must
	 * be.
	 */
	xfs_dinode_to_disk(dip, &ip->i_d);

	/* Wrap, we never let the log put out DI_MAX_FLUSH */
	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
		ip->i_d.di_flushiter = 0;

	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
	if (XFS_IFORK_Q(ip))
		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
	xfs_inobp_check(mp, bp);

	/*
	 * We've recorded everything logged in the inode, so we'd like to clear
	 * the ili_fields bits so we don't log and flush things unnecessarily.
	 * However, we can't stop logging all this information until the data
	 * we've copied into the disk buffer is written to disk.  If we did we
	 * might overwrite the copy of the inode in the log with all the data
	 * after re-logging only part of it, and in the face of a crash we
	 * wouldn't have all the data we need to recover.
	 *
	 * What we do is move the bits to the ili_last_fields field.  When
	 * logging the inode, these bits are moved back to the ili_fields field.
	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
	 * know that the information those bits represent is permanently on
	 * disk.  As long as the flush completes before the inode is logged
	 * again, then both ili_fields and ili_last_fields will be cleared.
	 *
	 * We can play with the ili_fields bits here, because the inode lock
	 * must be held exclusively in order to set bits there and the flush
	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
	 * done routine can tell whether or not to look in the AIL.  Also, store
	 * the current LSN of the inode so that we can tell whether the item has
	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
	 * need the AIL lock, because it is a 64 bit value that cannot be read
	 * atomically.
	 */
	iip->ili_last_fields = iip->ili_fields;
	iip->ili_fields = 0;
	iip->ili_logged = 1;

	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
				&iip->ili_item.li_lsn);

	/*
	 * Attach the function xfs_iflush_done to the inode's
	 * buffer.  This will remove the inode from the AIL
	 * and unlock the inode's flush lock when the inode is
	 * completely written to disk.
	 */
	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);

	/* update the lsn in the on disk inode if required */
	if (ip->i_d.di_version == 3)
		dip->di_lsn = cpu_to_be64(iip->ili_item.li_lsn);

	/* generate the checksum. */
	xfs_dinode_calc_crc(mp, dip);

	ASSERT(bp->b_fspriv != NULL);
	ASSERT(bp->b_iodone != NULL);
	return 0;

corrupt_out:
	return -EFSCORRUPTED;
} ; Sample JSON Format Confermily Expected output: "examples" => "cwe": "xxx"; "message": "xxx"
    
 'cwe': ['CWE-19'], 'message': 'xfs: optimise away log forces on timestamp updates for fdatasync

xfs: timestamp updates cause excessive fdatasync log traffic

Sage Weil reported that a ceph test workload was writing to the
log on every fdatasync during an overwrite workload. Event tracing
showed that the only metadata modification being made was the
timestamp updates during the write(2) syscall, but fdatasync(2)
is supposed to ignore them. The key observation was that the
transactions in the log all looked like this:

INODE: #regs: 4   ino: 0x8b  flags: 0x45   dsize: 32

And contained a flags field of 0x45 or 0x85, and had data and
attribute forks following the inode core. This means that the
timestamp updates were triggering dirty relogging of previously
logged parts of the inode that hadn't yet been flushed back to
disk.

There are two parts to this problem. The first is that XFS relogs
dirty regions in subsequent transactions, so it carries around the
fields that have been dirtied since the last time the inode was
written back to disk, not since the last time the inode was forced
into the log.

The second part is that on v5 filesystems, the inode change count
update during inode dirtying also sets the XFS_ILOG_CORE flag, so
on v5 filesystems this makes a timestamp update dirty the entire
inode.

As a result when fdatasync is run, it looks at the dirty fields in
the inode, and sees more than just the timestamp flag, even though
the only metadata change since the last fdatasync was just the
timestamps. Hence we force the log on every subsequent fdatasync
even though it is not needed.

To fix this, add a new field to the inode log item that tracks
changes since the last time fsync/fdatasync forced the log to flush
the changes to the journal. This flag is updated when we dirty the
inode, but we do it before updating the change count so it does not
carry the "core dirty" flag from timestamp updates. The fields are
zeroed when the inode is marked clean (due to writeback/freeing) or
when an fsync/datasync forces the log. Hence if we only dirty the
timestamps on the inode between fsync/fdatasync calls, the fdatasync
will not trigger another log force.

Over 100 runs of the test program:

Ext4 baseline:
	runtime: 1.63s +/- 0.24s
	avg lat: 1.59ms +/- 0.24ms
	iops: ~2000

XFS, vanilla kernel:
        runtime: 2.45s +/- 0.18s
	avg lat: 2.39ms +/- 0.18ms
	log forces: ~400/s
	iops: ~1000

XFS, patched kernel:
        runtime: 1.49s +/- 0.26s
	avg lat: 1.46ms +/- 0.25ms
	log forces: ~30/s
	iops: ~1500

Reported-by: Sage Weil <sage@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>'