X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fquota.c;h=9f237d6182c90e10129f6810279da32259fab6fe;hb=275391a482c436282dde57beeffc5d61b229fdd2;hp=d14d872646d4fc0b4082b50e6722d7467ed79d5c;hpb=977127174a7dff52d17faeeb4c4949a54221881f;p=linux-2.6-omap-h63xx.git

diff --git a/fs/quota.c b/fs/quota.c
index d14d872646d..9f237d6182c 100644
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -11,10 +11,10 @@
 #include <asm/current.h>
 #include <asm/uaccess.h>
 #include <linux/kernel.h>
-#include <linux/smp_lock.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/buffer_head.h>
+#include <linux/capability.h>
 #include <linux/quotaops.h>
 
 /* Check validity of generic quotactl commands */
@@ -157,7 +157,6 @@ static int check_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t
 static void quota_sync_sb(struct super_block *sb, int type)
 {
 	int cnt;
-	struct inode *discard[MAXQUOTAS];
 
 	sb->s_qcop->quota_sync(sb, type);
 	/* This is not very clever (and fast) but currently I don't know about
@@ -167,29 +166,21 @@ static void quota_sync_sb(struct super_block *sb, int type)
 		sb->s_op->sync_fs(sb, 1);
 	sync_blockdev(sb->s_bdev);
 
-	/* Now when everything is written we can discard the pagecache so
-	 * that userspace sees the changes. We need i_mutex and so we could
-	 * not do it inside dqonoff_sem. Moreover we need to be carefull
-	 * about races with quotaoff() (that is the reason why we have own
-	 * reference to inode). */
-	down(&sb_dqopt(sb)->dqonoff_sem);
+	/*
+	 * Now when everything is written we can discard the pagecache so
+	 * that userspace sees the changes.
+	 */
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		discard[cnt] = NULL;
 		if (type != -1 && cnt != type)
 			continue;
 		if (!sb_has_quota_enabled(sb, cnt))
 			continue;
-		discard[cnt] = igrab(sb_dqopt(sb)->files[cnt]);
-	}
-	up(&sb_dqopt(sb)->dqonoff_sem);
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (discard[cnt]) {
-			mutex_lock(&discard[cnt]->i_mutex);
-			truncate_inode_pages(&discard[cnt]->i_data, 0);
-			mutex_unlock(&discard[cnt]->i_mutex);
-			iput(discard[cnt]);
-		}
+		mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, I_MUTEX_QUOTA);
+		truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
+		mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
 	}
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 }
 
 void sync_dquots(struct super_block *sb, int type)
@@ -336,6 +327,34 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, void
 	return 0;
 }
 
+/*
+ * 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
@@ -346,25 +365,15 @@ 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);