GFS2: Get rid of I_MUTEX_QUOTA usage

GFS2 uses i_mutex on its system quota inode to synchronize writes to
quota file. Since this is an internal inode to GFS2 (not part of directory
hiearchy or visible by user) we are safe to define locking rules for it. So
let's just get it its own locking class to make it clear.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e5af9dc420ef0c3f1d9a40034b7a63b5791c04f0..e443966c810697e50f71b37afb807db62828335f 100644 (file)
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -19,6 +19,7 @@
 #include <linux/mount.h>
 #include <linux/gfs2_ondisk.h>
 #include <linux/quotaops.h>
+#include <linux/lockdep.h>
 
 #include "gfs2.h"
 #include "incore.h"
@@ -766,6 +767,7 @@ fail:
        return error;
 }
 
+static struct lock_class_key gfs2_quota_imutex_key;
 
 static int init_inodes(struct gfs2_sbd *sdp, int undo)
 {
@@ -803,6 +805,12 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
                fs_err(sdp, "can't get quota file inode: %d\n", error);
                goto fail_rindex;
        }
+       /*
+        * i_mutex on quota files is special. Since this inode is hidden system
+        * file, we are safe to define locking ourselves.
+        */
+       lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
+                         &gfs2_quota_imutex_key);
 
        error = gfs2_rindex_update(sdp);
        if (error)

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 420bc3805ccc4740f6dd04069724baf6098a5042..4021deca61ef3b14558d361823802e8c1ba64fb1 100644 (file)
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -782,7 +782,7 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
                return -ENOMEM;
 
        sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
-       mutex_lock_nested(&ip->i_inode.i_mutex, I_MUTEX_QUOTA);
+       mutex_lock(&ip->i_inode.i_mutex);
        for (qx = 0; qx < num_qd; qx++) {
                error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
                                           GL_NOCACHE, &ghs[qx]);