xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL
In preparation for adding coordination between extent unmap operations
and busy dax-pages, update xfs_break_layouts() to permit it to be called
with the mmap lock held. This lock scheme will be required for
coordinating the break of 'dax layouts' (non-idle dax (ZONE_DEVICE)
pages mapped into the file's address space). Breaking dax layouts will
be added to xfs_break_layouts() in a future patch, for now this preps
the unmap call sites to take and hold XFS_MMAPLOCK_EXCL over the call to
xfs_break_layouts().
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <darrick.wong@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 89fb1eb..4151fad 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -614,7 +614,7 @@ xfs_ioc_space(
struct xfs_inode *ip = XFS_I(inode);
struct iattr iattr;
enum xfs_prealloc_flags flags = 0;
- uint iolock = XFS_IOLOCK_EXCL;
+ uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
int error;
/*
@@ -648,9 +648,6 @@ xfs_ioc_space(
if (error)
goto out_unlock;
- xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
- iolock |= XFS_MMAPLOCK_EXCL;
-
switch (bf->l_whence) {
case 0: /*SEEK_SET*/
break;