From 9b94fcc39822b450af823b3d8cbef6b53ce87ed9 Mon Sep 17 00:00:00 2001 From: Iustin Pop Date: Mon, 2 Feb 2015 10:26:26 +1100 Subject: [PATCH] xfs: fix behaviour of XFS_IOC_FSSETXATTR on directories Currently, the ioctl handling code for XFS_IOC_FSSETXATTR treats all targets as regular files: it refuses to change the extent size if extents are allocated. This is wrong for directories, as there the extent size is only used as a default for children. The patch fixes this issue and improves validation of flag combinations: - only disallow extent size changes after extents have been allocated for regular files - only allow XFS_XFLAG_EXTSIZE for regular files - only allow XFS_XFLAG_EXTSZINHERIT for directories - automatically clear the flags if the extent size is zero Thanks to Dave Chinner for guidance on the proper fix for this issue. [dchinner: ported changes onto cleanup series. Makes changes clear and obvious.] [dchinner: added comments documenting validity checking rules.] Signed-off-by: Iustin Pop Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/xfs_ioctl.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 1f186d2eec06..0f6b6abb7c7a 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1098,6 +1098,20 @@ out_cancel: return ERR_PTR(error); } +/* + * extent size hint validation is somewhat cumbersome. Rules are: + * + * 1. extent size hint is only valid for directories and regular files + * 2. XFS_XFLAG_EXTSIZE is only valid for regular files + * 3. XFS_XFLAG_EXTSZINHERIT is only valid for directories. + * 4. can only be changed on regular files if no extents are allocated + * 5. can be changed on directories at any time + * 6. extsize hint of 0 turns off hints, clears inode flags. + * 7. Extent size must be a multiple of the appropriate block size. + * 8. for non-realtime files, the extent size hint must be limited + * to half the AG size to avoid alignment extending the extent beyond the + * limits of the AG. + */ int xfs_ioctl_setattr_check_extsize( struct xfs_inode *ip, @@ -1105,20 +1119,17 @@ xfs_ioctl_setattr_check_extsize( { struct xfs_mount *mp = ip->i_mount; - /* Can't change extent size if any extents are allocated. */ - if (ip->i_d.di_nextents && + if ((fa->fsx_xflags & XFS_XFLAG_EXTSIZE) && !S_ISREG(ip->i_d.di_mode)) + return -EINVAL; + + if ((fa->fsx_xflags & XFS_XFLAG_EXTSZINHERIT) && + !S_ISDIR(ip->i_d.di_mode)) + return -EINVAL; + + if (S_ISREG(ip->i_d.di_mode) && ip->i_d.di_nextents && ((ip->i_d.di_extsize << mp->m_sb.sb_blocklog) != fa->fsx_extsize)) return -EINVAL; - /* - * Extent size must be a multiple of the appropriate block 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_fsblock_t extsize_fsb; @@ -1138,7 +1149,9 @@ xfs_ioctl_setattr_check_extsize( if (fa->fsx_extsize % size) return -EINVAL; - } + } else + fa->fsx_xflags &= ~(XFS_XFLAG_EXTSIZE | XFS_XFLAG_EXTSZINHERIT); + return 0; } @@ -1169,8 +1182,6 @@ xfs_ioctl_setattr_check_projid( return 0; } - - STATIC int xfs_ioctl_setattr( xfs_inode_t *ip, -- 2.20.1