Commit 20f829999c38 ("gfs2: Rework read and page fault locking") has lifted the
glock lock taking from the low-level ->readpage and ->readahead address space
operations to the higher-level ->read_iter file and ->fault vm operations. The
glocks are still taken in LM_ST_SHARED mode only. On filesystems mounted
without the noatime option, ->read_iter needs to update the atime as well
though, so we currently run into a failed locking mode assertion in
gfs2_dirty_inode. Fix that by taking the glock in LM_ST_EXCLUSIVE mode on
filesystems mounted without the noatime mount option.
Faulting in pages doesn't update the atime, so in the ->fault vm operation,
taking the glock in LM_ST_SHARED mode is enough.
Reported-by: Alexander Aring <[email protected]>
Fixes: 20f829999c38 ("gfs2: Rework read and page fault locking")
Cc: [email protected] # v5.8+
Signed-off-by: Andreas Gruenbacher <[email protected]>
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index b39b339feddc..162a81873dcd 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -849,6 +849,7 @@ static ssize_t gfs2_file_read_iter(struct kiocb *iocb,
struct iov_iter *to)
struct gfs2_inode *ip;
struct gfs2_holder gh;
size_t written = 0;
+ unsigned int state;
ssize_t ret;
if (iocb->ki_flags & IOCB_DIRECT) {
@@ -871,7 +872,8 @@ static ssize_t gfs2_file_read_iter(struct kiocb *iocb,
struct iov_iter *to)
return ret;
}
ip = GFS2_I(iocb->ki_filp->f_mapping->host);
- gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+ state = IS_NOATIME(&ip->i_inode) ? LM_ST_SHARED : LM_ST_EXCLUSIVE;
+ gfs2_holder_init(ip->i_gl, state, 0, &gh);
ret = gfs2_glock_nq(&gh);
if (ret)
goto out_uninit;
