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authorDarrick J. Wong2024-08-04 14:39:57 -0700
committerChandan Babu R2024-08-14 21:20:24 +0530
commit8d16762047c627073955b7ed171a36addaf7b1ff (patch)
treec4f51c346739f90b72e23cf0461bf6549cd3cecb
parent04d6dbb55301a29aeb9a197e6b0012cdc265f1e4 (diff)
xfs: conditionally allow FS_XFLAG_REALTIME changes if S_DAX is set
If a file has the S_DAX flag (aka fsdax access mode) set, we cannot allow users to change the realtime flag unless the datadev and rtdev both support fsdax access modes. Even if there are no extents allocated to the file, the setattr thread could be racing with another thread that has already started down the write code paths. Fixes: ba23cba9b3bdc ("fs: allow per-device dax status checking for filesystems") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
-rw-r--r--fs/xfs/xfs_ioctl.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 4e933db75b12..6b13666d4e96 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -483,6 +483,17 @@ xfs_ioctl_setattr_xflags(
/* Can't change realtime flag if any extents are allocated. */
if (ip->i_df.if_nextents || ip->i_delayed_blks)
return -EINVAL;
+
+ /*
+ * If S_DAX is enabled on this file, we can only switch the
+ * device if both support fsdax. We can't update S_DAX because
+ * there might be other threads walking down the access paths.
+ */
+ if (IS_DAX(VFS_I(ip)) &&
+ (mp->m_ddev_targp->bt_daxdev == NULL ||
+ (mp->m_rtdev_targp &&
+ mp->m_rtdev_targp->bt_daxdev == NULL)))
+ return -EINVAL;
}
if (rtflag) {