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>

1 files changed, 37 insertions, 84 deletions

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 4d7fdc4443b9..dcf7db91fc95 100644
--- 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;
 }
 
 /*