From 5315837daee7ed76c31ef643915f7d76ef8c1aa3 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 27 Jan 2011 12:18:18 +1100 Subject: [PATCH] xfs: limit extsize to size of AGs and/or MAXEXTLEN MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The extent size hint can be set to larger than an AG. This means that the alignment process can push the range to be allocated outside the bounds of the AG, resulting in assert failures or corrupted bmbt records. Similarly, if the extsize is larger than the maximum extent size supported, the alignment process will produce extents that are too large to fit into the bmbt records, resulting in a different type of assert/corruption failure. Fix this by limiting extsize at the time іt is set firstly to be less than MAXEXTLEN, then to be a maximum of half the size of the AGs in the filesystem for non-realtime inodes. Realtime inodes do not allocate out of AGs, so don't have to be restricted by the size of AGs. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Alex Elder --- fs/xfs/linux-2.6/xfs_ioctl.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index b06ede1d0be..f5e2a19e0f8 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -985,10 +985,22 @@ xfs_ioctl_setattr( /* * Extent size must be a multiple of the appropriate block - * size, if set at all. + * size, if set at all. It must also be smaller than the + * maximum extent size supported by the filesystem. + * + * Also, for non-realtime files, limit the extent size hint to + * half the size of the AGs in the filesystem so alignment + * doesn't result in extents larger than an AG. */ if (fa->fsx_extsize != 0) { - xfs_extlen_t size; + xfs_extlen_t size; + xfs_fsblock_t extsize_fsb; + + extsize_fsb = XFS_B_TO_FSB(mp, fa->fsx_extsize); + if (extsize_fsb > MAXEXTLEN) { + code = XFS_ERROR(EINVAL); + goto error_return; + } if (XFS_IS_REALTIME_INODE(ip) || ((mask & FSX_XFLAGS) && @@ -997,6 +1009,10 @@ xfs_ioctl_setattr( mp->m_sb.sb_blocklog; } else { size = mp->m_sb.sb_blocksize; + if (extsize_fsb > mp->m_sb.sb_agblocks / 2) { + code = XFS_ERROR(EINVAL); + goto error_return; + } } if (fa->fsx_extsize % size) { -- 2.20.1