xfs: implement inode change count (dc037ad7) · Commits · 戴 / test

For CRC enabled filesystems, add support for the monotonic inode version change counter that is needed by protocols like NFSv4 for determining if the inode has changed in any way at all between two unrelated operations on the inode. This bumps the change count the first time an inode is dirtied in a transaction. Since all modifications to the inode are logged, this will catch all changes that are made to the inode, including timestamp updates that occur during data writes. Signed-off-by:

Dave Chinner <dchinner@redhat.com> Reviewed-by:

Mark Tinguely <tinguely@sgi.com> Reviewed-by:

Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by:

Ben Myers <bpm@sgi.com>

fs/xfs/xfs_super.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1477,6 +1477,10 @@ xfs_fs_fill_super(
		sb->s_time_gran = 1;
		set_posix_acl_flag(sb);

		/* version 5 superblocks support inode version counters. */
		if (XFS_SB_VERSION_NUM(&mp->m_sb) == XFS_SB_VERSION_5)
		sb->s_flags \|= MS_I_VERSION;

		error = xfs_mountfs(mp);
		if (error)
		goto out_filestream_unmount;

fs/xfs/xfs_trans_inode.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -112,6 +112,17 @@ xfs_trans_log_inode(
		ASSERT(ip->i_itemp != NULL);
		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

		/*
		* First time we log the inode in a transaction, bump the inode change
		* counter if it is configured for this to occur.
		*/
		if (!(ip->i_itemp->ili_item.li_desc->lid_flags & XFS_LID_DIRTY) &&
		IS_I_VERSION(VFS_I(ip))) {
		inode_inc_iversion(VFS_I(ip));
		ip->i_d.di_changecount = VFS_I(ip)->i_version;
		flags \|= XFS_ILOG_CORE;
		}

		tp->t_flags \|= XFS_TRANS_DIRTY;
		ip->i_itemp->ili_item.li_desc->lid_flags \|= XFS_LID_DIRTY;

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