[GFS2] fix inode meta data corruption

Fix a nasty inode meta data corruption issue by keeping the buffer head in
icache array. This buffer needs to stay in memory until journal flush occurs
Otherwise, gfs2_meta_inode_buffer could do a disk read before the inode hits
disk. It ends up with meta data corruptions. The buffer will be released as
part of the existing journal flush logic.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 15 insertions, 5 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 34f7bcdea1e9..013f00b90cc2 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -244,6 +244,11 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
         return 0;
 }
 
+static void gfs2_inode_bh(struct gfs2_inode *ip, struct buffer_head *bh)
+{
+        ip->i_cache[0] = bh;
+}
+
 /**
  * gfs2_inode_refresh - Refresh the incore copy of the dinode
  * @ip: The GFS2 inode
@@ -688,7 +693,7 @@ out:
 static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                         const struct gfs2_inum_host *inum, unsigned int mode,
                         unsigned int uid, unsigned int gid,
-                        const u64 *generation, dev_t dev)
+                        const u64 *generation, dev_t dev, struct buffer_head **bhp)
 {
         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
         struct gfs2_dinode *di;
@@ -743,13 +748,15 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
         di->di_mtime_nsec = cpu_to_be32(tv.tv_nsec);
         di->di_ctime_nsec = cpu_to_be32(tv.tv_nsec);
         memset(&di->di_reserved, 0, sizeof(di->di_reserved));
+        
+        set_buffer_uptodate(dibh);
 
-        brelse(dibh);
+        *bhp = dibh;
 }
 
 static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                        unsigned int mode, const struct gfs2_inum_host *inum,
-                       const u64 *generation, dev_t dev)
+                       const u64 *generation, dev_t dev, struct buffer_head **bhp)
 {
         struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
         unsigned int uid, gid;
@@ -770,7 +777,7 @@ static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
         if (error)
                 goto out_quota;
 
-        init_dinode(dip, gl, inum, mode, uid, gid, generation, dev);
+        init_dinode(dip, gl, inum, mode, uid, gid, generation, dev, bhp);
         gfs2_quota_change(dip, +1, uid, gid);
         gfs2_trans_end(sdp);
 
@@ -909,6 +916,7 @@ struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
         struct gfs2_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
         int error;
         u64 generation;
+        struct buffer_head *bh=NULL;
 
         if (!name->len || name->len > GFS2_FNAMESIZE)
                 return ERR_PTR(-ENAMETOOLONG);
@@ -935,7 +943,7 @@ struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
         if (error)
                 goto fail_gunlock;
 
-        error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev);
+        error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, &bh);
         if (error)
                 goto fail_gunlock2;
 
@@ -945,6 +953,8 @@ struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
         if (IS_ERR(inode))
                 goto fail_gunlock2;
 
+        gfs2_inode_bh(GFS2_I(inode), bh);
+
         error = gfs2_inode_refresh(GFS2_I(inode));
         if (error)
                 goto fail_gunlock2;