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>
This commit is contained in:
Dan Williams 2018-03-12 14:12:29 -07:00
parent 5fac7408d8
commit c63a8eae63
4 changed files with 13 additions and 14 deletions

View File

@ -734,7 +734,7 @@ xfs_file_fallocate(
struct xfs_inode *ip = XFS_I(inode);
long error;
enum xfs_prealloc_flags flags = 0;
uint iolock = XFS_IOLOCK_EXCL;
uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
loff_t new_size = 0;
bool do_file_insert = false;
@ -748,9 +748,6 @@ xfs_file_fallocate(
if (error)
goto out_unlock;
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
iolock |= XFS_MMAPLOCK_EXCL;
if (mode & FALLOC_FL_PUNCH_HOLE) {
error = xfs_free_file_space(ip, offset, len);
if (error)

View File

@ -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;

View File

@ -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 {

View File

@ -43,7 +43,8 @@ xfs_break_layouts(
while ((error = break_layout(inode, false) == -EWOULDBLOCK)) {
xfs_iunlock(ip, *iolock);
error = break_layout(inode, true);
*iolock = XFS_IOLOCK_EXCL;
*iolock &= ~XFS_IOLOCK_SHARED;
*iolock |= XFS_IOLOCK_EXCL;
xfs_ilock(ip, *iolock);
}