[PATCH 6/6] xfs: fold xfs_ilock_for_write_fault into xfs_write_fault

Christoph Hellwig
2024-06-23T05:45:26Z

Now that the page fault handler has been refactored, the only caller
of xfs_ilock_for_write_fault is simple enough and calls it
unconditionally. Fold the logic and expand the comments explaining it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_file.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 904be41f3e5ec6..4cdc54dc96862e 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -227,21 +227,6 @@ xfs_ilock_iocb_for_write(
return 0;
}

-static unsigned int
-xfs_ilock_for_write_fault(
- struct xfs_inode *ip)
-{
- /* get a shared lock if no remapping in progress */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- if (!xfs_iflags_test(ip, XFS_IREMAPPING))
- return XFS_MMAPLOCK_SHARED;
-
- /* wait for remapping to complete */
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
- return XFS_MMAPLOCK_EXCL;
-}
-
STATIC ssize_t
xfs_file_dio_read(
struct kiocb *iocb,
@@ -1294,18 +1279,30 @@ xfs_write_fault(
unsigned int order)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
- unsigned int lock_mode;
+ struct xfs_inode *ip = XFS_I(inode);
+ unsigned int lock_mode = XFS_MMAPLOCK_SHARED;
vm_fault_t ret;

sb_start_pagefault(inode->i_sb);
file_update_time(vmf->vma->vm_file);

- lock_mode = xfs_ilock_for_write_fault(XFS_I(inode));
+ /*
+ * Normally we only need the shared mmaplock, but if a reflink remap is
+ * in progress we take the exclusive lock to wait for the remap to
+ * finish before taking a write fault.
+ */
+ xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+ if (xfs_iflags_test(ip, XFS_IREMAPPING)) {
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+ xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+ lock_mode = XFS_MMAPLOCK_EXCL;
+ }
+
if (IS_DAX(inode))
ret = xfs_dax_fault_locked(vmf, order, true);
else
ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
- xfs_iunlock(XFS_I(inode), lock_mode);
+ xfs_iunlock(ip, lock_mode);

sb_end_pagefault(inode->i_sb);
return ret;
--
2.43.0