ocfs2: Use __dquot_transfer to avoid lock inversion

dquot_transfer() acquires own references to dquots via dqget(). Thus it waits
for dq_lock which creates a lock inversion because dq_lock ranks above
transaction start but transaction is already started in ocfs2_setattr(). Fix
the problem by passing own references directly to __dquot_transfer.

Acked-by: Joel Becker <Joel.Becker@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 5 insertions, 12 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index e127c53ec2e7..97e54b9e654b 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -933,9 +933,8 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
         struct ocfs2_super *osb = OCFS2_SB(sb);
         struct buffer_head *bh = NULL;
         handle_t *handle = NULL;
-        int qtype;
-        struct dquot *transfer_from[MAXQUOTAS] = { };
         struct dquot *transfer_to[MAXQUOTAS] = { };
+        int qtype;
 
         mlog_entry("(0x%p, '%.*s')\n", dentry,
                    dentry->d_name.len, dentry->d_name.name);
@@ -1019,9 +1018,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
                     OCFS2_FEATURE_RO_COMPAT_USRQUOTA)) {
                         transfer_to[USRQUOTA] = dqget(sb, attr->ia_uid,
                                                       USRQUOTA);
-                        transfer_from[USRQUOTA] = dqget(sb, inode->i_uid,
-                                                        USRQUOTA);
-                        if (!transfer_to[USRQUOTA] || !transfer_from[USRQUOTA]) {
+                        if (!transfer_to[USRQUOTA]) {
                                 status = -ESRCH;
                                 goto bail_unlock;
                         }
@@ -1031,9 +1028,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
                     OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)) {
                         transfer_to[GRPQUOTA] = dqget(sb, attr->ia_gid,
                                                       GRPQUOTA);
-                        transfer_from[GRPQUOTA] = dqget(sb, inode->i_gid,
-                                                        GRPQUOTA);
-                        if (!transfer_to[GRPQUOTA] || !transfer_from[GRPQUOTA]) {
+                        if (!transfer_to[GRPQUOTA]) {
                                 status = -ESRCH;
                                 goto bail_unlock;
                         }
@@ -1045,7 +1040,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
                         mlog_errno(status);
                         goto bail_unlock;
                 }
-                status = dquot_transfer(inode, attr);
+                status = __dquot_transfer(inode, transfer_to);
                 if (status < 0)
                         goto bail_commit;
         } else {
@@ -1085,10 +1080,8 @@ bail:
         brelse(bh);
 
         /* Release quota pointers in case we acquired them */
-        for (qtype = 0; qtype < MAXQUOTAS; qtype++) {
+        for (qtype = 0; qtype < MAXQUOTAS; qtype++)
                 dqput(transfer_to[qtype]);
-                dqput(transfer_from[qtype]);
-        }
 
         if (!status && attr->ia_valid & ATTR_MODE) {
                 status = ocfs2_acl_chmod(inode);