Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / fs / quota / quota.c

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index b299961e1edbb8ef4dd16d28ccfd5c7cba2bfa28..b34bdb25490c8956b4733c29771bea3109ec2fcf 100644 (file)
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -64,18 +64,15 @@ static int quota_sync_all(int type)
 }
 
 static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
-                        void __user *addr)
+                        struct path *path)
 {
-       char *pathname;
-       int ret = -ENOSYS;
-
-       pathname = getname(addr);
-       if (IS_ERR(pathname))
-               return PTR_ERR(pathname);
-       if (sb->s_qcop->quota_on)
-               ret = sb->s_qcop->quota_on(sb, type, id, pathname);
-       putname(pathname);
-       return ret;
+       if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
+               return -ENOSYS;
+       if (sb->s_qcop->quota_on_meta)
+               return sb->s_qcop->quota_on_meta(sb, type, id);
+       if (IS_ERR(path))
+               return PTR_ERR(path);
+       return sb->s_qcop->quota_on(sb, type, id, path);
 }
 
 static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
@@ -241,7 +238,7 @@ static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 
 /* Copy parameters and call proper function */
 static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
-                      void __user *addr)
+                      void __user *addr, struct path *path)
 {
        int ret;
 
@@ -256,7 +253,7 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 
        switch (cmd) {
        case Q_QUOTAON:
-               return quota_quotaon(sb, type, cmd, id, addr);
+               return quota_quotaon(sb, type, cmd, id, path);
        case Q_QUOTAOFF:
                if (!sb->s_qcop->quota_off)
                        return -ENOSYS;
@@ -335,6 +332,7 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 {
        uint cmds, type;
        struct super_block *sb = NULL;
+       struct path path, *pathp = NULL;
        int ret;
 
        cmds = cmd >> SUBCMDSHIFT;
@@ -351,12 +349,27 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
                return -ENODEV;
        }
 
+       /*
+        * Path for quotaon has to be resolved before grabbing superblock
+        * because that gets s_umount sem which is also possibly needed by path
+        * resolution (think about autofs) and thus deadlocks could arise.
+        */
+       if (cmds == Q_QUOTAON) {
+               ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW, &path);
+               if (ret)
+                       pathp = ERR_PTR(ret);
+               else
+                       pathp = &path;
+       }
+
        sb = quotactl_block(special);
        if (IS_ERR(sb))
                return PTR_ERR(sb);
 
-       ret = do_quotactl(sb, type, cmds, id, addr);
+       ret = do_quotactl(sb, type, cmds, id, addr, pathp);
 
        drop_super(sb);
+       if (pathp && !IS_ERR(pathp))
+               path_put(pathp);
        return ret;
 }