xfs_agnumber_t
xfs_filestream_lookup_ag(
	xfs_inode_t	*ip)
{
	xfs_mru_cache_t	*cache;
	fstrm_item_t	*item;
	xfs_agnumber_t	ag;
	int		ref;

	if (!(ip->i_d.di_mode & (S_IFREG | S_IFDIR))) {
		ASSERT(0);
		return NULLAGNUMBER;
	}

	cache = ip->i_mount->m_filestream;
	item = xfs_mru_cache_lookup(cache, ip->i_ino);
	if (!item) {
		TRACE_LOOKUP(ip->i_mount, ip, NULL, NULLAGNUMBER, 0);
		return NULLAGNUMBER;
	}

	ASSERT(ip == item->ip);
	ag = item->ag;
	ref = xfs_filestream_peek_ag(ip->i_mount, ag);
	xfs_mru_cache_done(cache);

	TRACE_LOOKUP(ip->i_mount, ip, item->pip, ag, ref);
	return ag;
}
Beispiel #2
0
/*
 * Find the right allocation group for a file, either by finding an
 * existing file stream or creating a new one.
 *
 * Returns NULLAGNUMBER in case of an error.
 */
xfs_agnumber_t
xfs_filestream_lookup_ag(
	struct xfs_inode	*ip)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_inode	*pip = NULL;
	xfs_agnumber_t		startag, ag = NULLAGNUMBER;
	struct xfs_mru_cache_elem *mru;

	ASSERT(S_ISREG(ip->i_d.di_mode));

	pip = xfs_filestream_get_parent(ip);
	if (!pip)
		goto out;

	mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
	if (mru) {
		ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
		xfs_mru_cache_done(mp->m_filestream);

		trace_xfs_filestream_lookup(ip, ag);
		goto out;
	}

	/*
	 * Set the starting AG using the rotor for inode32, otherwise
	 * use the directory inode's AG.
	 */
	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
		xfs_agnumber_t	 rotorstep = xfs_rotorstep;
		startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
		mp->m_agfrotor = (mp->m_agfrotor + 1) %
		                 (mp->m_sb.sb_agcount * rotorstep);
	} else
		startag = XFS_INO_TO_AGNO(mp, pip->i_ino);

	if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
		ag = NULLAGNUMBER;
out:
	IRELE(pip);
	return ag;
}
int
xfs_filestream_new_ag(
	xfs_bmalloca_t	*ap,
	xfs_agnumber_t	*agp)
{
	int		flags, err;
	xfs_inode_t	*ip, *pip = NULL;
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	xfs_extlen_t	minlen;
	fstrm_item_t	*dir, *file;
	xfs_agnumber_t	ag = NULLAGNUMBER;

	ip = ap->ip;
	mp = ip->i_mount;
	cache = mp->m_filestream;
	minlen = ap->alen;
	*agp = NULLAGNUMBER;

	/*
	 * Look for the file in the cache, removing it if it's found.  Doing
	 * this allows it to be held across the dir lookup that follows.
	 */
	file = xfs_mru_cache_remove(cache, ip->i_ino);
	if (file) {
		ASSERT(ip == file->ip);

		/* Save the file's parent inode and old AG number for later. */
		pip = file->pip;
		ag = file->ag;

		/* Look for the file's directory in the cache. */
		dir = xfs_mru_cache_lookup(cache, pip->i_ino);
		if (dir) {
			ASSERT(pip == dir->ip);

			/*
			 * If the directory has already moved on to a new AG,
			 * use that AG as the new AG for the file. Don't
			 * forget to twiddle the AG refcounts to match the
			 * movement.
			 */
			if (dir->ag != file->ag) {
				xfs_filestream_put_ag(mp, file->ag);
				xfs_filestream_get_ag(mp, dir->ag);
				*agp = file->ag = dir->ag;
			}

			xfs_mru_cache_done(cache);
		}

		/*
		 * Put the file back in the cache.  If this fails, the free
		 * function needs to be called to tidy up in the same way as if
		 * the item had simply expired from the cache.
		 */
		err = xfs_mru_cache_insert(cache, ip->i_ino, file);
		if (err) {
			xfs_fstrm_free_func(ip->i_ino, file);
			return err;
		}

		/*
		 * If the file's AG was moved to the directory's new AG, there's
		 * nothing more to be done.
		 */
		if (*agp != NULLAGNUMBER) {
			TRACE_MOVEAG(mp, ip, pip,
					ag, xfs_filestream_peek_ag(mp, ag),
					*agp, xfs_filestream_peek_ag(mp, *agp));
			return 0;
		}
	}

	/*
	 * If the file's parent directory is known, take its iolock in exclusive
	 * mode to prevent two sibling files from racing each other to migrate
	 * themselves and their parent to different AGs.
	 */
	if (pip)
		xfs_ilock(pip, XFS_IOLOCK_EXCL);

	/*
	 * A new AG needs to be found for the file.  If the file's parent
	 * directory is also known, it will be moved to the new AG as well to
	 * ensure that files created inside it in future use the new AG.
	 */
	ag = (ag == NULLAGNUMBER) ? 0 : (ag + 1) % mp->m_sb.sb_agcount;
	flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
	        (ap->low ? XFS_PICK_LOWSPACE : 0);

	err = _xfs_filestream_pick_ag(mp, ag, agp, flags, minlen);
	if (err || *agp == NULLAGNUMBER)
		goto exit;

	/*
	 * If the file wasn't found in the file cache, then its parent directory
	 * inode isn't known.  For this to have happened, the file must either
	 * be pre-existing, or it was created long enough ago that its cache
	 * entry has expired.  This isn't the sort of usage that the filestreams
	 * allocator is trying to optimise, so there's no point trying to track
	 * its new AG somehow in the filestream data structures.
	 */
	if (!pip) {
		TRACE_ORPHAN(mp, ip, *agp);
		goto exit;
	}

	/* Associate the parent inode with the AG. */
	err = _xfs_filestream_update_ag(pip, NULL, *agp);
	if (err)
		goto exit;

	/* Associate the file inode with the AG. */
	err = _xfs_filestream_update_ag(ip, pip, *agp);
	if (err)
		goto exit;

	TRACE_MOVEAG(mp, ip, pip, NULLAGNUMBER, 0,
			*agp, xfs_filestream_peek_ag(mp, *agp));

exit:
	/*
	 * If _xfs_filestream_pick_ag() returned a valid AG, remove the
	 * reference it took on it, since the file and directory will have taken
	 * their own now if they were successfully cached.
	 */
	if (*agp != NULLAGNUMBER)
		xfs_filestream_put_ag(mp, *agp);
	else
		*agp = 0;

	if (pip)
		xfs_iunlock(pip, XFS_IOLOCK_EXCL);

	return err;
}
int
xfs_filestream_associate(
	xfs_inode_t	*pip,
	xfs_inode_t	*ip)
{
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	fstrm_item_t	*item;
	xfs_agnumber_t	ag, rotorstep, startag;
	int		err = 0;

	ASSERT(pip->i_d.di_mode & S_IFDIR);
	ASSERT(ip->i_d.di_mode & S_IFREG);
	if (!(pip->i_d.di_mode & S_IFDIR) || !(ip->i_d.di_mode & S_IFREG))
		return -EINVAL;

	mp = pip->i_mount;
	cache = mp->m_filestream;

	/*
	 * We have a problem, Houston.
	 *
	 * Taking the iolock here violates inode locking order - we already
	 * hold the ilock. Hence if we block getting this lock we may never
	 * wake. Unfortunately, that means if we can't get the lock, we're
	 * screwed in terms of getting a stream association - we can't spin
	 * waiting for the lock because someone else is waiting on the lock we
	 * hold and we cannot drop that as we are in a transaction here.
	 *
	 * Lucky for us, this inversion is not a problem because it's a
	 * directory inode that we are trying to lock here.
	 *
	 * So, if we can't get the iolock without sleeping then just give up
	 */
	if (!xfs_ilock_nowait(pip, XFS_IOLOCK_EXCL))
		return 1;

	/* If the parent directory is already in the cache, use its AG. */
	item = xfs_mru_cache_lookup(cache, pip->i_ino);
	if (item) {
		ASSERT(item->ip == pip);
		ag = item->ag;
		xfs_mru_cache_done(cache);

		TRACE_LOOKUP(mp, pip, pip, ag, xfs_filestream_peek_ag(mp, ag));
		err = _xfs_filestream_update_ag(ip, pip, ag);

		goto exit;
	}

	/*
	 * Set the starting AG using the rotor for inode32, otherwise
	 * use the directory inode's AG.
	 */
	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
		rotorstep = xfs_rotorstep;
		startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
		mp->m_agfrotor = (mp->m_agfrotor + 1) %
		                 (mp->m_sb.sb_agcount * rotorstep);
	} else
		startag = XFS_INO_TO_AGNO(mp, pip->i_ino);

	/* Pick a new AG for the parent inode starting at startag. */
	err = _xfs_filestream_pick_ag(mp, startag, &ag, 0, 0);
	if (err || ag == NULLAGNUMBER)
		goto exit_did_pick;

	/* Associate the parent inode with the AG. */
	err = _xfs_filestream_update_ag(pip, NULL, ag);
	if (err)
		goto exit_did_pick;

	/* Associate the file inode with the AG. */
	err = _xfs_filestream_update_ag(ip, pip, ag);
	if (err)
		goto exit_did_pick;

	TRACE_ASSOCIATE(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag));

exit_did_pick:
	/*
	 * If _xfs_filestream_pick_ag() returned a valid AG, remove the
	 * reference it took on it, since the file and directory will have taken
	 * their own now if they were successfully cached.
	 */
	if (ag != NULLAGNUMBER)
		xfs_filestream_put_ag(mp, ag);

exit:
	xfs_iunlock(pip, XFS_IOLOCK_EXCL);
	return -err;
}
static int
_xfs_filestream_update_ag(
	xfs_inode_t	*ip,
	xfs_inode_t	*pip,
	xfs_agnumber_t	ag)
{
	int		err = 0;
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	fstrm_item_t	*item;
	xfs_agnumber_t	old_ag;
	xfs_inode_t	*old_pip;

	/*
	 * Either ip is a regular file and pip is a directory, or ip is a
	 * directory and pip is NULL.
	 */
	ASSERT(ip && (((ip->i_d.di_mode & S_IFREG) && pip &&
	               (pip->i_d.di_mode & S_IFDIR)) ||
	              ((ip->i_d.di_mode & S_IFDIR) && !pip)));

	mp = ip->i_mount;
	cache = mp->m_filestream;

	item = xfs_mru_cache_lookup(cache, ip->i_ino);
	if (item) {
		ASSERT(item->ip == ip);
		old_ag = item->ag;
		item->ag = ag;
		old_pip = item->pip;
		item->pip = pip;
		xfs_mru_cache_done(cache);

		/*
		 * If the AG has changed, drop the old ref and take a new one,
		 * effectively transferring the reference from old to new AG.
		 */
		if (ag != old_ag) {
			xfs_filestream_put_ag(mp, old_ag);
			xfs_filestream_get_ag(mp, ag);
		}

		/*
		 * If ip is a file and its pip has changed, drop the old ref and
		 * take a new one.
		 */
		if (pip && pip != old_pip) {
			IRELE(old_pip);
			IHOLD(pip);
		}

		TRACE_UPDATE(mp, ip, old_ag, xfs_filestream_peek_ag(mp, old_ag),
				ag, xfs_filestream_peek_ag(mp, ag));
		return 0;
	}

	item = kmem_zone_zalloc(item_zone, KM_MAYFAIL);
	if (!item)
		return ENOMEM;

	item->ag = ag;
	item->ip = ip;
	item->pip = pip;

	err = xfs_mru_cache_insert(cache, ip->i_ino, item);
	if (err) {
		kmem_zone_free(item_zone, item);
		return err;
	}

	/* Take a reference on the AG. */
	xfs_filestream_get_ag(mp, ag);

	/*
	 * Take a reference on the inode itself regardless of whether it's a
	 * regular file or a directory.
	 */
	IHOLD(ip);

	/*
	 * In the case of a regular file, take a reference on the parent inode
	 * as well to ensure it remains in-core.
	 */
	if (pip)
		IHOLD(pip);

	TRACE_UPDATE(mp, ip, ag, xfs_filestream_peek_ag(mp, ag),
			ag, xfs_filestream_peek_ag(mp, ag));

	return 0;
}
int
xfs_filestream_new_ag(
	xfs_bmalloca_t	*ap,
	xfs_agnumber_t	*agp)
{
	int		flags, err;
	xfs_inode_t	*ip, *pip = NULL;
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	xfs_extlen_t	minlen;
	fstrm_item_t	*dir, *file;
	xfs_agnumber_t	ag = NULLAGNUMBER;

	ip = ap->ip;
	mp = ip->i_mount;
	cache = mp->m_filestream;
	minlen = ap->length;
	*agp = NULLAGNUMBER;

	file = xfs_mru_cache_remove(cache, ip->i_ino);
	if (file) {
		ASSERT(ip == file->ip);

		
		pip = file->pip;
		ag = file->ag;

		
		dir = xfs_mru_cache_lookup(cache, pip->i_ino);
		if (dir) {
			ASSERT(pip == dir->ip);

			if (dir->ag != file->ag) {
				xfs_filestream_put_ag(mp, file->ag);
				xfs_filestream_get_ag(mp, dir->ag);
				*agp = file->ag = dir->ag;
			}

			xfs_mru_cache_done(cache);
		}

		err = xfs_mru_cache_insert(cache, ip->i_ino, file);
		if (err) {
			xfs_fstrm_free_func(ip->i_ino, file);
			return err;
		}

		if (*agp != NULLAGNUMBER) {
			TRACE_MOVEAG(mp, ip, pip,
					ag, xfs_filestream_peek_ag(mp, ag),
					*agp, xfs_filestream_peek_ag(mp, *agp));
			return 0;
		}
	}

	if (pip)
		xfs_ilock(pip, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);

	ag = (ag == NULLAGNUMBER) ? 0 : (ag + 1) % mp->m_sb.sb_agcount;
	flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
	        (ap->flist->xbf_low ? XFS_PICK_LOWSPACE : 0);

	err = _xfs_filestream_pick_ag(mp, ag, agp, flags, minlen);
	if (err || *agp == NULLAGNUMBER)
		goto exit;

	if (!pip) {
		TRACE_ORPHAN(mp, ip, *agp);
		goto exit;
	}

	
	err = _xfs_filestream_update_ag(pip, NULL, *agp);
	if (err)
		goto exit;

	
	err = _xfs_filestream_update_ag(ip, pip, *agp);
	if (err)
		goto exit;

	TRACE_MOVEAG(mp, ip, pip, NULLAGNUMBER, 0,
			*agp, xfs_filestream_peek_ag(mp, *agp));

exit:
	if (*agp != NULLAGNUMBER)
		xfs_filestream_put_ag(mp, *agp);
	else
		*agp = 0;

	if (pip)
		xfs_iunlock(pip, XFS_IOLOCK_EXCL);

	return err;
}
int
xfs_filestream_associate(
	xfs_inode_t	*pip,
	xfs_inode_t	*ip)
{
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	fstrm_item_t	*item;
	xfs_agnumber_t	ag, rotorstep, startag;
	int		err = 0;

	ASSERT(S_ISDIR(pip->i_d.di_mode));
	ASSERT(S_ISREG(ip->i_d.di_mode));
	if (!S_ISDIR(pip->i_d.di_mode) || !S_ISREG(ip->i_d.di_mode))
		return -EINVAL;

	mp = pip->i_mount;
	cache = mp->m_filestream;

	if (!xfs_ilock_nowait(pip, XFS_IOLOCK_EXCL))
		return 1;

	
	item = xfs_mru_cache_lookup(cache, pip->i_ino);
	if (item) {
		ASSERT(item->ip == pip);
		ag = item->ag;
		xfs_mru_cache_done(cache);

		TRACE_LOOKUP(mp, pip, pip, ag, xfs_filestream_peek_ag(mp, ag));
		err = _xfs_filestream_update_ag(ip, pip, ag);

		goto exit;
	}

	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
		rotorstep = xfs_rotorstep;
		startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
		mp->m_agfrotor = (mp->m_agfrotor + 1) %
		                 (mp->m_sb.sb_agcount * rotorstep);
	} else
		startag = XFS_INO_TO_AGNO(mp, pip->i_ino);

	
	err = _xfs_filestream_pick_ag(mp, startag, &ag, 0, 0);
	if (err || ag == NULLAGNUMBER)
		goto exit_did_pick;

	
	err = _xfs_filestream_update_ag(pip, NULL, ag);
	if (err)
		goto exit_did_pick;

	
	err = _xfs_filestream_update_ag(ip, pip, ag);
	if (err)
		goto exit_did_pick;

	TRACE_ASSOCIATE(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag));

exit_did_pick:
	if (ag != NULLAGNUMBER)
		xfs_filestream_put_ag(mp, ag);

exit:
	xfs_iunlock(pip, XFS_IOLOCK_EXCL);
	return -err;
}
static int
_xfs_filestream_update_ag(
	xfs_inode_t	*ip,
	xfs_inode_t	*pip,
	xfs_agnumber_t	ag)
{
	int		err = 0;
	xfs_mount_t	*mp;
	xfs_mru_cache_t	*cache;
	fstrm_item_t	*item;
	xfs_agnumber_t	old_ag;
	xfs_inode_t	*old_pip;

	ASSERT(ip && ((S_ISREG(ip->i_d.di_mode) && pip &&
	               S_ISDIR(pip->i_d.di_mode)) ||
	              (S_ISDIR(ip->i_d.di_mode) && !pip)));

	mp = ip->i_mount;
	cache = mp->m_filestream;

	item = xfs_mru_cache_lookup(cache, ip->i_ino);
	if (item) {
		ASSERT(item->ip == ip);
		old_ag = item->ag;
		item->ag = ag;
		old_pip = item->pip;
		item->pip = pip;
		xfs_mru_cache_done(cache);

		if (ag != old_ag) {
			xfs_filestream_put_ag(mp, old_ag);
			xfs_filestream_get_ag(mp, ag);
		}

		if (pip && pip != old_pip) {
			IRELE(old_pip);
			IHOLD(pip);
		}

		TRACE_UPDATE(mp, ip, old_ag, xfs_filestream_peek_ag(mp, old_ag),
				ag, xfs_filestream_peek_ag(mp, ag));
		return 0;
	}

	item = kmem_zone_zalloc(item_zone, KM_MAYFAIL);
	if (!item)
		return ENOMEM;

	item->ag = ag;
	item->ip = ip;
	item->pip = pip;

	err = xfs_mru_cache_insert(cache, ip->i_ino, item);
	if (err) {
		kmem_zone_free(item_zone, item);
		return err;
	}

	
	xfs_filestream_get_ag(mp, ag);

	IHOLD(ip);

	if (pip)
		IHOLD(pip);

	TRACE_UPDATE(mp, ip, ag, xfs_filestream_peek_ag(mp, ag),
			ag, xfs_filestream_peek_ag(mp, ag));

	return 0;
}