[PATCH] gfs2: gfs2_setattr_size error path fix

[Andreas Gruenbacher <agruenba@xxxxxxxxxx>]

When gfs2_setattr_size() fails, it calls gfs2_rs_delete(ip, NULL) to get
rid of any reservations the inode may have.  Instead, it should pass in
the inode's write count as the second parameter to allow
gfs2_rs_delete() to figure out if the inode has any writers left.

In a next step, there are two instances of gfs2_rs_delete(ip, NULL) left
where we know that there can be no other users of the inode.  Replace
those with gfs2_rs_deltree(&ip->i_res) to avoid the unnecessary write
count check.

With that, gfs2_rs_delete() is only called with the inode's actual write
count, so get rid of the second parameter.

Fixes: a097dc7e24cb ("GFS2: Make rgrp reservations part of the gfs2_inode structure")
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index d67108489148..fbdb7a30470a 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -2146,7 +2146,7 @@ int gfs2_setattr_size(struct inode *inode, u64 newsize)
 
 	ret = do_shrink(inode, newsize);
 out:
-	gfs2_rs_delete(ip, NULL);
+	gfs2_rs_delete(ip);
 	gfs2_qa_put(ip);
 	return ret;
 }
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 8c39a8571b1f..5bac4f6e8e05 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -706,7 +706,7 @@ static int gfs2_release(struct inode *inode, struct file *file)
 
 	if (file->f_mode & FMODE_WRITE) {
 		if (gfs2_rs_active(&ip->i_res))
-			gfs2_rs_delete(ip, &inode->i_writecount);
+			gfs2_rs_delete(ip);
 		gfs2_qa_put(ip);
 	}
 	return 0;
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 89905f4f29bb..66a123306aec 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -793,7 +793,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 		if (free_vfs_inode) /* else evict will do the put for us */
 			gfs2_glock_put(ip->i_gl);
 	}
-	gfs2_rs_delete(ip, NULL);
+	gfs2_rs_deltree(&ip->i_res);
 	gfs2_qa_put(ip);
 fail_free_acls:
 	posix_acl_release(default_acl);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 9b04a570c582..9df8a84f85a6 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -680,13 +680,14 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs)
 /**
  * gfs2_rs_delete - delete a multi-block reservation
  * @ip: The inode for this reservation
- * @wcount: The inode's write count, or NULL
  *
  */
-void gfs2_rs_delete(struct gfs2_inode *ip, atomic_t *wcount)
+void gfs2_rs_delete(struct gfs2_inode *ip)
 {
+	struct inode *inode = &ip->i_inode;
+
 	down_write(&ip->i_rw_mutex);
-	if ((wcount == NULL) || (atomic_read(wcount) <= 1))
+	if (atomic_read(&inode->i_writecount) <= 1)
 		gfs2_rs_deltree(&ip->i_res);
 	up_write(&ip->i_rw_mutex);
 }
diff --git a/fs/gfs2/rgrp.h b/fs/gfs2/rgrp.h
index 3e2ca1fb4305..46dd94e9e085 100644
--- a/fs/gfs2/rgrp.h
+++ b/fs/gfs2/rgrp.h
@@ -45,7 +45,7 @@ extern int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
 			     bool dinode, u64 *generation);
 
 extern void gfs2_rs_deltree(struct gfs2_blkreserv *rs);
-extern void gfs2_rs_delete(struct gfs2_inode *ip, atomic_t *wcount);
+extern void gfs2_rs_delete(struct gfs2_inode *ip);
 extern void __gfs2_free_blocks(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
 			       u64 bstart, u32 blen, int meta);
 extern void gfs2_free_meta(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 64c67090f503..143a47359d1b 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1396,7 +1396,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	truncate_inode_pages_final(&inode->i_data);
 	if (ip->i_qadata)
 		gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
-	gfs2_rs_delete(ip, NULL);
+	gfs2_rs_deltree(&ip->i_res);
 	gfs2_ordered_del_inode(ip);
 	clear_inode(inode);
 	gfs2_dir_hash_inval(ip);