quota: clean up checks for supported quota methods

Move the checks for sb->s_qcop->foo next to the actual calls for them, same
for sb_has_quota_active checks where applicable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 4d7fdc4..dcf7db9 100644 (file)
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -33,54 +33,6 @@ static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
        if (sb && !sb->s_qcop)
                return -ENOSYS;
 
-       switch (cmd) {
-               case Q_GETFMT:
-                       break;
-               case Q_QUOTAON:
-                       if (!sb->s_qcop->quota_on)
-                               return -ENOSYS;
-                       break;
-               case Q_QUOTAOFF:
-                       if (!sb->s_qcop->quota_off)
-                               return -ENOSYS;
-                       break;
-               case Q_SETINFO:
-                       if (!sb->s_qcop->set_info)
-                               return -ENOSYS;
-                       break;
-               case Q_GETINFO:
-                       if (!sb->s_qcop->get_info)
-                               return -ENOSYS;
-                       break;
-               case Q_SETQUOTA:
-                       if (!sb->s_qcop->set_dqblk)
-                               return -ENOSYS;
-                       break;
-               case Q_GETQUOTA:
-                       if (!sb->s_qcop->get_dqblk)
-                               return -ENOSYS;
-                       break;
-               case Q_SYNC:
-                       if (sb && !sb->s_qcop->quota_sync)
-                               return -ENOSYS;
-                       break;
-               default:
-                       return -EINVAL;
-       }
-
-       /* Is quota turned on for commands which need it? */
-       switch (cmd) {
-               case Q_GETFMT:
-               case Q_GETINFO:
-               case Q_SETINFO:
-               case Q_SETQUOTA:
-               case Q_GETQUOTA:
-                       /* This is just an informative test so we are satisfied
-                        * without the lock */
-                       if (!sb_has_quota_active(sb, type))
-                               return -ESRCH;
-       }
-
        /* Check privileges */
        if (cmd == Q_GETQUOTA) {
                if (((type == USRQUOTA && current_euid() != id) ||
@@ -106,33 +58,6 @@ static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd,
        if (!sb->s_qcop)
                return -ENOSYS;
 
-       switch (cmd) {
-               case Q_XQUOTAON:
-               case Q_XQUOTAOFF:
-               case Q_XQUOTARM:
-                       if (!sb->s_qcop->set_xstate)
-                               return -ENOSYS;
-                       break;
-               case Q_XGETQSTAT:
-                       if (!sb->s_qcop->get_xstate)
-                               return -ENOSYS;
-                       break;
-               case Q_XSETQLIM:
-                       if (!sb->s_qcop->set_xquota)
-                               return -ENOSYS;
-                       break;
-               case Q_XGETQUOTA:
-                       if (!sb->s_qcop->get_xquota)
-                               return -ENOSYS;
-                       break;
-               case Q_XQUOTASYNC:
-                       if (!sb->s_qcop->quota_sync)
-                               return -ENOSYS;
-                       break;
-               default:
-                       return -EINVAL;
-       }
-
        /* Check privileges */
        if (cmd == Q_XGETQUOTA) {
                if (((type == XQM_USRQUOTA && current_euid() != id) ||
@@ -238,12 +163,13 @@ static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
                         void __user *addr)
 {
        char *pathname;
-       int ret;
+       int ret = -ENOSYS;
 
        pathname = getname(addr);
        if (IS_ERR(pathname))
                return PTR_ERR(pathname);
-       ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
+       if (sb->s_qcop->quota_on)
+               ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0);
        putname(pathname);
        return ret;
 }
@@ -269,6 +195,10 @@ static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
        struct if_dqinfo info;
        int ret;
 
+       if (!sb_has_quota_active(sb, type))
+               return -ESRCH;
+       if (!sb->s_qcop->get_info)
+               return -ENOSYS;
        ret = sb->s_qcop->get_info(sb, type, &info);
        if (!ret && copy_to_user(addr, &info, sizeof(info)))
                return -EFAULT;
@@ -281,6 +211,10 @@ static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
 
        if (copy_from_user(&info, addr, sizeof(info)))
                return -EFAULT;
+       if (!sb_has_quota_active(sb, type))
+               return -ESRCH;
+       if (!sb->s_qcop->set_info)
+               return -ENOSYS;
        return sb->s_qcop->set_info(sb, type, &info);
 }
 
@@ -290,6 +224,10 @@ static int quota_getquota(struct super_block *sb, int type, qid_t id,
        struct if_dqblk idq;
        int ret;
 
+       if (!sb_has_quota_active(sb, type))
+               return -ESRCH;
+       if (!sb->s_qcop->get_dqblk)
+               return -ENOSYS;
        ret = sb->s_qcop->get_dqblk(sb, type, id, &idq);
        if (ret)
                return ret;
@@ -305,6 +243,10 @@ static int quota_setquota(struct super_block *sb, int type, qid_t id,
 
        if (copy_from_user(&idq, addr, sizeof(idq)))
                return -EFAULT;
+       if (!sb_has_quota_active(sb, type))
+               return -ESRCH;
+       if (!sb->s_qcop->set_dqblk)
+               return -ENOSYS;
        return sb->s_qcop->set_dqblk(sb, type, id, &idq);
 }
 
@@ -314,6 +256,8 @@ static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
 
        if (copy_from_user(&flags, addr, sizeof(flags)))
                return -EFAULT;
+       if (!sb->s_qcop->set_xstate)
+               return -ENOSYS;
        return sb->s_qcop->set_xstate(sb, flags, cmd);
 }
 
@@ -321,7 +265,9 @@ static int quota_getxstate(struct super_block *sb, void __user *addr)
 {
        struct fs_quota_stat fqs;
        int ret;
-               
+
+       if (!sb->s_qcop->get_xstate)
+               return -ENOSYS;
        ret = sb->s_qcop->get_xstate(sb, &fqs);
        if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
                return -EFAULT;
@@ -335,6 +281,8 @@ static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 
        if (copy_from_user(&fdq, addr, sizeof(fdq)))
                return -EFAULT;
+       if (!sb->s_qcop->set_xquota)
+               return -ENOSYS;
        return sb->s_qcop->set_xquota(sb, type, id, &fdq);
 }
 
@@ -344,6 +292,8 @@ static int quota_getxquota(struct super_block *sb, int type, qid_t id,
        struct fs_disk_quota fdq;
        int ret;
 
+       if (!sb->s_qcop->get_xquota)
+               return -ENOSYS;
        ret = sb->s_qcop->get_xquota(sb, type, id, &fdq);
        if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
                return -EFAULT;
@@ -358,6 +308,8 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
        case Q_QUOTAON:
                return quota_quotaon(sb, type, cmd, id, addr);
        case Q_QUOTAOFF:
+               if (!sb->s_qcop->quota_off)
+                       return -ENOSYS;
                return sb->s_qcop->quota_off(sb, type, 0);
        case Q_GETFMT:
                return quota_getfmt(sb, type, addr);
@@ -370,9 +322,11 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
        case Q_SETQUOTA:
                return quota_setquota(sb, type, id, addr);
        case Q_SYNC:
-               if (sb)
+               if (sb) {
+                       if (!sb->s_qcop->quota_sync)
+                               return -ENOSYS;
                        sync_quota_sb(sb, type);
-               else
+               } else
                        sync_dquots(type);
                return 0;
        case Q_XQUOTAON:
@@ -386,13 +340,12 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
        case Q_XGETQUOTA:
                return quota_getxquota(sb, type, id, addr);
        case Q_XQUOTASYNC:
+               if (!sb->s_qcop->quota_sync)
+                       return -ENOSYS;
                return sb->s_qcop->quota_sync(sb, type);
-       /* We never reach here unless validity check is broken */
        default:
-               BUG();
+               return -EINVAL;
        }
-
-       return 0;
 }
 
 /*