On Fri, Oct 11, 2019 at 03:03:15PM +0200, Christoph Hellwig wrote: > If we always have to write out of place preallocating blocks is > pointless. We already check for this in the normal falloc path, but > the check was missig in the legacy ALLOCSP path. This function handles other things than preallocation, such as XFS_IOC_ZERO_RANGE and XFS_IOC_UNRESVSP, which call xfs_zero_file_space and xfs_free_file_space, respectively. We don't prohibit fallocate from calling those two functions on an always_cow inode, so why do that here? --D > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > fs/xfs/xfs_ioctl.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > index d58f0d6a699e..abf7a102376f 100644 > --- a/fs/xfs/xfs_ioctl.c > +++ b/fs/xfs/xfs_ioctl.c > @@ -33,6 +33,7 @@ > #include "xfs_sb.h" > #include "xfs_ag.h" > #include "xfs_health.h" > +#include "xfs_reflink.h" > > #include <linux/mount.h> > #include <linux/namei.h> > @@ -607,6 +608,9 @@ xfs_ioc_space( > if (!S_ISREG(inode->i_mode)) > return -EINVAL; > > + if (xfs_is_always_cow_inode(ip)) > + return -EOPNOTSUPP; > + > if (filp->f_flags & O_DSYNC) > flags |= XFS_PREALLOC_SYNC; > if (filp->f_mode & FMODE_NOCMTIME) > -- > 2.20.1 >
