xfs: take i_mmap_lock on extent manipulation operations (e8e9ad42) · Commits · 戴 / test

Now we have the i_mmap_lock being held across the page fault IO path, we now add extent manipulation operation exclusion by adding the lock to the paths that directly modify extent maps. This includes truncate, hole punching and other fallocate based operations. The operations will now take both the i_iolock and the i_mmaplock in exclusive mode, thereby ensuring that all IO and page faults block without holding any page locks while the extent manipulation is in progress. This gives us the lock order during truncate of i_iolock -> i_mmaplock -> page_lock -> i_lock, hence providing the same lock order as the iolock provides the normal IO path without involving the mmap_sem. Signed-off-by:

Dave Chinner <dchinner@redhat.com> Reviewed-by:

Brian Foster <bfoster@redhat.com> Signed-off-by:

Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_file.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -841,6 +841,9 @@ 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)

fs/xfs/xfs_ioctl.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -643,6 +643,9 @@ 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;

fs/xfs/xfs_iops.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -765,6 +765,7 @@ xfs_setattr_size(
		return error;

		ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
		ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
		ASSERT(S_ISREG(ip->i_d.di_mode));
		ASSERT((iattr->ia_valid & (ATTR_UID\|ATTR_GID\|ATTR_ATIME\|ATTR_ATIME_SET\|
		ATTR_MTIME_SET\|ATTR_KILL_PRIV\|ATTR_TIMES_SET)) == 0);
		@@ -984,8 +985,12 @@ xfs_vn_setattr(

		xfs_ilock(ip, iolock);
		error = xfs_break_layouts(dentry->d_inode, &iolock);
		if (!error)
		if (!error) {
		xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
		iolock \|= XFS_MMAPLOCK_EXCL;

		error = xfs_setattr_size(ip, iattr);
		}
		xfs_iunlock(ip, iolock);
		} else {
		error = xfs_setattr_nonsize(ip, iattr, 0);

Admin message