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_iops.c b/fs/xfs/xfs_iops.c
index a3ed3c8..138fb36 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1031,13 +1031,17 @@ xfs_vn_setattr(
if (iattr->ia_valid & ATTR_SIZE) {
struct xfs_inode *ip = XFS_I(d_inode(dentry));
- uint iolock = XFS_IOLOCK_EXCL;
-
- error = xfs_break_layouts(d_inode(dentry), &iolock);
- if (error)
- return error;
+ uint iolock;
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+ iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+
+ error = xfs_break_layouts(d_inode(dentry), &iolock);
+ if (error) {
+ xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
+ return error;
+ }
+
error = xfs_vn_setattr_size(dentry, iattr);
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
} else {
