From b7f55d928e75557295c1ac280c291b738905b6fb Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sat, 15 May 2021 17:27:14 +0200 Subject: [PATCH] gfs2: Fix mmap locking for write faults When a write fault occurs, we need to take the inode glock of the underlying inode in exclusive mode. Otherwise, there's no guarantee that the dirty page will be written back to disk. Signed-off-by: Andreas Gruenbacher --- fs/gfs2/file.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 493a83e3f590..8a35a0196b6d 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -540,9 +540,11 @@ static vm_fault_t gfs2_fault(struct vm_fault *vmf) struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; vm_fault_t ret; + u16 state; int err; - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + state = (vmf->flags & FAULT_FLAG_WRITE) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; + gfs2_holder_init(ip->i_gl, state, 0, &gh); err = gfs2_glock_nq(&gh); if (err) { ret = block_page_mkwrite_return(err);