xfs: implement inode change count

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>
This commit is contained in:
Dave Chinner 2013-06-27 16:04:59 +10:00 committed by Ben Myers
parent ddf6ad0143
commit dc037ad7d2
2 changed files with 15 additions and 0 deletions

View file

@ -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;

View file

@ -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;