gfs2: Inode dirtying fix

With the recent iomap write page reclaim deadlock fix, it turns out that the
GLF_DIRTY flag isn't always set when it needs to be anymore: previously, this
happened as a side effect of always adding the inode buffer head to the current
transaction with gfs2_trans_add_meta, but this isn't happening consistently
anymore.  Fix by removing an additional unnecessary gfs2_trans_add_meta call
and by setting the GLF_DIRTY flag in gfs2_iomap_end.

(The GLF_DIRTY flag causes inode_go_sync to flush the transaction log when
syncing out the glock of that inode.  When the flag isn't set, inode_go_sync
will skip inodes, including ones with an i_state of I_DIRTY_PAGES, which will
lead to cluster incoherency.)

In addition, in gfs2_iomap_page_done, if the metadata has changed, mark the
inode as I_DIRTY_DATASYNC to have the inode added to the current transaction:
we don't expect metadata to change here, but let's err on the safe side.

Fixes: d0a22a4b03b8 ("gfs2: Fix iomap write page reclaim deadlock");
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 79581b9bdebb357a62cfd0d821b4de0d74349b03..4df26ef2b2b15689bcfa058b8997bc0da3f99a67 100644 (file)
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1002,11 +1002,16 @@ static void gfs2_iomap_page_done(struct inode *inode, loff_t pos,
                                 unsigned copied, struct page *page,
                                 struct iomap *iomap)
 {
+       struct gfs2_trans *tr = current->journal_info;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_sbd *sdp = GFS2_SB(inode);
 
        if (page && !gfs2_is_stuffed(ip))
                gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied);
+
+       if (tr->tr_num_buf_new)
+               __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+
        gfs2_trans_end(sdp);
 }
 
@@ -1099,8 +1104,6 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos,
                tr = current->journal_info;
                if (tr->tr_num_buf_new)
                        __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
-               else
-                       gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[0]);
 
                gfs2_trans_end(sdp);
        }
@@ -1181,10 +1184,16 @@ static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
 
        if (ip->i_qadata && ip->i_qadata->qa_qd_num)
                gfs2_quota_unlock(ip);
+
+       if (unlikely(!written))
+               goto out_unlock;
+
        if (iomap->flags & IOMAP_F_SIZE_CHANGED)
                mark_inode_dirty(inode);
-       gfs2_write_unlock(inode);
+       set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 
+out_unlock:
+       gfs2_write_unlock(inode);
 out:
        return 0;
 }