GFS2: rm on multiple nodes causes panic

This patch fixes a problem whereby simultaneous unlink, rmdir,
rename and link operations (e.g. rm -fR *) from multiple nodes
on the same GFS2 file system can cause kernel panics, hangs,
and/or memory corruption.  It also gets rid of all the non-rgrp
calls to gfs2_glock_nq_m.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 38 insertions, 18 deletions

diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index e2c62f73a778..35f6f032a026 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -159,9 +159,13 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
         gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
 
-        error = gfs2_glock_nq_m(2, ghs);
+        error = gfs2_glock_nq(ghs); /* parent */
         if (error)
-                goto out;
+                goto out_parent;
+
+        error = gfs2_glock_nq(ghs + 1); /* child */
+        if (error)
+                goto out_child;
 
         error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
         if (error)
@@ -245,8 +249,10 @@ out_alloc:
         if (alloc_required)
                 gfs2_alloc_put(dip);
 out_gunlock:
-        gfs2_glock_dq_m(2, ghs);
-out:
+        gfs2_glock_dq(ghs + 1);
+out_child:
+        gfs2_glock_dq(ghs);
+out_parent:
         gfs2_holder_uninit(ghs);
         gfs2_holder_uninit(ghs + 1);
         if (!error) {
@@ -302,7 +308,7 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
 
         error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
         if (error)
-                goto out_rgrp;
+                goto out_gunlock;
 
         error = gfs2_trans_begin(sdp, 2*RES_DINODE + RES_LEAF + RES_RG_BIT, 0);
         if (error)
@@ -316,6 +322,7 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
 
 out_end_trans:
         gfs2_trans_end(sdp);
+out_gunlock:
         gfs2_glock_dq(ghs + 2);
 out_rgrp:
         gfs2_holder_uninit(ghs + 2);
@@ -485,7 +492,6 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
         struct gfs2_holder ri_gh;
         int error;
 
-
         error = gfs2_rindex_hold(sdp, &ri_gh);
         if (error)
                 return error;
@@ -495,9 +501,17 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
         rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);
         gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);
 
-        error = gfs2_glock_nq_m(3, ghs);
+        error = gfs2_glock_nq(ghs); /* parent */
         if (error)
-                goto out;
+                goto out_parent;
+
+        error = gfs2_glock_nq(ghs + 1); /* child */
+        if (error)
+                goto out_child;
+
+        error = gfs2_glock_nq(ghs + 2); /* rgrp */
+        if (error)
+                goto out_rgrp;
 
         error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
         if (error)
@@ -523,11 +537,15 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
         gfs2_trans_end(sdp);
 
 out_gunlock:
-        gfs2_glock_dq_m(3, ghs);
-out:
-        gfs2_holder_uninit(ghs);
-        gfs2_holder_uninit(ghs + 1);
+        gfs2_glock_dq(ghs + 2);
+out_rgrp:
         gfs2_holder_uninit(ghs + 2);
+        gfs2_glock_dq(ghs + 1);
+out_child:
+        gfs2_holder_uninit(ghs + 1);
+        gfs2_glock_dq(ghs);
+out_parent:
+        gfs2_holder_uninit(ghs);
         gfs2_glock_dq_uninit(&ri_gh);
         return error;
 }
@@ -639,9 +657,11 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                         gfs2_holder_init(nrgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh++);
         }
 
-        error = gfs2_glock_nq_m(num_gh, ghs);
-        if (error)
-                goto out_uninit;
+        for (x = 0; x < num_gh; x++) {
+                error = gfs2_glock_nq(ghs + x);
+                if (error)
+                        goto out_gunlock;
+        }
 
         /* Check out the old directory */
 
@@ -804,10 +824,10 @@ out_alloc:
         if (alloc_required)
                 gfs2_alloc_put(ndip);
 out_gunlock:
-        gfs2_glock_dq_m(num_gh, ghs);
-out_uninit:
-        for (x = 0; x < num_gh; x++)
+        while (x--) {
+                gfs2_glock_dq(ghs + x);
                 gfs2_holder_uninit(ghs + x);
+        }
 out_gunlock_r:
         if (dir_rename)
                 gfs2_glock_dq_uninit(&r_gh);