Revert "GFS2: Prevent delete work from occurring on glocks used for create"

Since commit a0e3cc65 ("gfs2: Turn gl_delete into a delayed work"), we're
cancelling any pending delete work of an iopen glock before attaching a new
inode to that glock in gfs2_create_inode.  This means that delete_work_func can
no longer be queued or running when attaching the iopen glock to the new inode,
and we can revert commit a4923865 ("GFS2: Prevent delete work from
occurring on glocks used for create"), which tried to achieve the same but in a
racy way.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -857,12 +857,6 @@ static void delete_work_func(struct work_struct *work)
 	clear_bit(GLF_PENDING_DELETE, &gl->gl_flags);
 	spin_unlock(&gl->gl_lockref.lock);
 
-	/* If someone's using this glock to create a new dinode, the block must
-	   have been freed by another node, then re-used, in which case our
-	   iopen callback is too late after the fact. Ignore it. */
-	if (test_bit(GLF_INODE_CREATING, &gl->gl_flags))
-		goto out;
-
 	if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
 		/*
 		 * If we can evict the inode, give the remote node trying to
@@ -2112,8 +2106,6 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
 		*p++ = 'o';
 	if (test_bit(GLF_BLOCKING, gflags))
 		*p++ = 'b';
-	if (test_bit(GLF_INODE_CREATING, gflags))
-		*p++ = 'c';
 	if (test_bit(GLF_PENDING_DELETE, gflags))
 		*p++ = 'P';
 	if (test_bit(GLF_FREEING, gflags))

fs/gfs2/incore.h

@@ -348,7 +348,6 @@ enum {
 	GLF_LRU				= 13,
 	GLF_OBJECT			= 14, /* Used only for tracing */
 	GLF_BLOCKING			= 15,
-	GLF_INODE_CREATING		= 16, /* Inode creation occurring */
 	GLF_PENDING_DELETE		= 17,
 	GLF_FREEING			= 18, /* Wait for glock to be freed */
 };

fs/gfs2/inode.c

@@ -609,7 +609,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	struct inode *inode = NULL;
 	struct gfs2_inode *dip = GFS2_I(dir), *ip;
 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
-	struct gfs2_glock *io_gl = NULL;
+	struct gfs2_glock *io_gl;
 	int error, free_vfs_inode = 1;
 	u32 aflags = 0;
 	unsigned blocks = 1;
@@ -750,8 +750,6 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	init_dinode(dip, ip, symname);
 	gfs2_trans_end(sdp);
 
-	BUG_ON(test_and_set_bit(GLF_INODE_CREATING, &io_gl->gl_flags));
-
 	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
 	if (error)
 		goto fail_gunlock2;
@@ -797,7 +795,6 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	gfs2_glock_dq_uninit(ghs);
 	gfs2_qa_put(ip);
 	gfs2_glock_dq_uninit(ghs + 1);
-	clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
 	gfs2_glock_put(io_gl);
 	gfs2_qa_put(dip);
 	return error;
@@ -806,7 +803,6 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	glock_clear_object(io_gl, ip);
 	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 fail_gunlock2:
-	clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
 	glock_clear_object(io_gl, ip);
 	gfs2_glock_put(io_gl);
 fail_free_inode: