1 files changed, 53 insertions, 0 deletions

diff --git a/fs/dquot.c b/fs/dquot.c
index ad88cf6fcbaf..0bcaf970bbb4 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -1153,6 +1153,28 @@ int dquot_drop(struct inode *inode)
         return 0;
 }
 
+/* Wrapper to remove references to quota structures from inode */
+void vfs_dq_drop(struct inode *inode)
+{
+        /* Here we can get arbitrary inode from clear_inode() so we have
+         * to be careful. OTOH we don't need locking as quota operations
+         * are allowed to change only at mount time */
+        if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
+            && inode->i_sb->dq_op->drop) {
+                int cnt;
+                /* Test before calling to rule out calls from proc and such
+                 * where we are not allowed to block. Note that this is
+                 * actually reliable test even without the lock - the caller
+                 * must assure that nobody can come after the DQUOT_DROP and
+                 * add quota pointers back anyway */
+                for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+                        if (inode->i_dquot[cnt] != NODQUOT)
+                                break;
+                if (cnt < MAXQUOTAS)
+                        inode->i_sb->dq_op->drop(inode);
+        }
+}
+
 /*
  * Following four functions update i_blocks+i_bytes fields and
  * quota information (together with appropriate checks)
@@ -1426,6 +1448,18 @@ warn_put_all:
         return ret;
 }
 
+/* Wrapper for transferring ownership of an inode */
+int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
+{
+        if (sb_any_quota_enabled(inode->i_sb) && !IS_NOQUOTA(inode)) {
+                vfs_dq_init(inode);
+                if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
+                        return 1;
+        }
+        return 0;
+}
+
+
 /*
  * Write info of quota file to disk
  */
@@ -1766,6 +1800,22 @@ out:
         return error;
 }
 
+/* Wrapper to turn on quotas when remounting rw */
+int vfs_dq_quota_on_remount(struct super_block *sb)
+{
+        int cnt;
+        int ret = 0, err;
+
+        if (!sb->s_qcop || !sb->s_qcop->quota_on)
+                return -ENOSYS;
+        for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+                err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
+                if (err < 0 && !ret)
+                        ret = err;
+        }
+        return ret;
+}
+
 /* Generic routine for getting common part of quota structure */
 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
 {
@@ -2101,8 +2151,11 @@ EXPORT_SYMBOL(dquot_release);
 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
 EXPORT_SYMBOL(dquot_initialize);
 EXPORT_SYMBOL(dquot_drop);
+EXPORT_SYMBOL(vfs_dq_drop);
 EXPORT_SYMBOL(dquot_alloc_space);
 EXPORT_SYMBOL(dquot_alloc_inode);
 EXPORT_SYMBOL(dquot_free_space);
 EXPORT_SYMBOL(dquot_free_inode);
 EXPORT_SYMBOL(dquot_transfer);
+EXPORT_SYMBOL(vfs_dq_transfer);
+EXPORT_SYMBOL(vfs_dq_quota_on_remount);