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Diffstat (limited to 'fs/quota.c')
-rw-r--r--fs/quota.c44
1 files changed, 31 insertions, 13 deletions
diff --git a/fs/quota.c b/fs/quota.c
index d6a2be826e2..b9dae76a0b6 100644
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -338,6 +338,34 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, void
}
/*
+ * look up a superblock on which quota ops will be performed
+ * - use the name of a block device to find the superblock thereon
+ */
+static inline struct super_block *quotactl_block(const char __user *special)
+{
+#ifdef CONFIG_BLOCK
+ struct block_device *bdev;
+ struct super_block *sb;
+ char *tmp = getname(special);
+
+ if (IS_ERR(tmp))
+ return ERR_PTR(PTR_ERR(tmp));
+ bdev = lookup_bdev(tmp);
+ putname(tmp);
+ if (IS_ERR(bdev))
+ return ERR_PTR(PTR_ERR(bdev));
+ sb = get_super(bdev);
+ bdput(bdev);
+ if (!sb)
+ return ERR_PTR(-ENODEV);
+
+ return sb;
+#else
+ return ERR_PTR(-ENODEV);
+#endif
+}
+
+/*
* This is the system call interface. This communicates with
* the user-level programs. Currently this only supports diskquota
* calls. Maybe we need to add the process quotas etc. in the future,
@@ -347,25 +375,15 @@ asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t
{
uint cmds, type;
struct super_block *sb = NULL;
- struct block_device *bdev;
- char *tmp;
int ret;
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
if (cmds != Q_SYNC || special) {
- tmp = getname(special);
- if (IS_ERR(tmp))
- return PTR_ERR(tmp);
- bdev = lookup_bdev(tmp);
- putname(tmp);
- if (IS_ERR(bdev))
- return PTR_ERR(bdev);
- sb = get_super(bdev);
- bdput(bdev);
- if (!sb)
- return -ENODEV;
+ sb = quotactl_block(special);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
}
ret = check_quotactl_valid(sb, type, cmds, id);