Commit 0e2af929 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: improve FSGROWFSRT precondition checking 



Improve the checking at the start of a realtime grow operation so that
we avoid accidentally set a new extent size that is too large and avoid
adding an rt volume to a filesystem with rmap or reflink because we
don't support rt rmap or reflink yet.

While we're at it, separate the checks so that we're only testing one
aspect at a time.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 5aa5b278

fs/xfs/xfs_rtalloc.c

+32 −7
Original line number Diff line number Diff line
@@ -923,16 +923,41 @@ xfs_growfs_rt( 
	uint8_t		*rsum_cache;	/* old summary cache */



	sbp = &mp->m_sb;

	/*

	 * Initial error checking.

	 */



	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;

	if (mp->m_rtdev_targp == NULL || mp->m_rbmip == NULL ||

	    (nrblocks = in->newblocks) <= sbp->sb_rblocks ||

	    (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))



	/* Needs to have been mounted with an rt device. */

	if (!XFS_IS_REALTIME_MOUNT(mp))

		return -EINVAL;

	/*

	 * Mount should fail if the rt bitmap/summary files don't load, but

	 * we'll check anyway.

	 */

	if (!mp->m_rbmip || !mp->m_rsumip)

		return -EINVAL;



	/* Shrink not supported. */

	if (in->newblocks <= sbp->sb_rblocks)

		return -EINVAL;



	/* Can only change rt extent size when adding rt volume. */

	if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)

		return -EINVAL;



	/* Range check the extent size. */

	if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||

	    XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)

		return -EINVAL;

	if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))



	/* Unsupported realtime features. */

	if (xfs_sb_version_hasrmapbt(&mp->m_sb) ||

	    xfs_sb_version_hasreflink(&mp->m_sb))

		return -EOPNOTSUPP;



	nrblocks = in->newblocks;

	error = xfs_sb_validate_fsb_count(sbp, nrblocks);

	if (error)

		return error;

	/*

	 * Read in the last block of the device, make sure it exists.