X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=fs%2Fnamei.c;h=8fc6f57b2a54946595d855623205b4394c0ed668;hp=f3069a3b6487d1457a8dae860b848f5737facad2;hb=f7c3ff94a296f2daf8f5f2e8be3e459636c3fdfd;hpb=a4cb4b1277a499ebced7f7534d5cfb11a30eb224;ds=sidebyside

diff --git a/fs/namei.c b/fs/namei.c
index f3069a3b6487..8fc6f57b2a54 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -554,24 +554,22 @@ static int complete_walk(struct nameidata *nd)
 
 static __always_inline void set_root(struct nameidata *nd)
 {
-	if (!nd->root.mnt)
-		get_fs_root(current->fs, &nd->root);
+	get_fs_root(current->fs, &nd->root);
 }
 
 static int link_path_walk(const char *, struct nameidata *);
 
-static __always_inline void set_root_rcu(struct nameidata *nd)
+static __always_inline unsigned set_root_rcu(struct nameidata *nd)
 {
-	if (!nd->root.mnt) {
-		struct fs_struct *fs = current->fs;
-		unsigned seq;
+	struct fs_struct *fs = current->fs;
+	unsigned seq, res;
 
-		do {
-			seq = read_seqcount_begin(&fs->seq);
-			nd->root = fs->root;
-			nd->seq = __read_seqcount_begin(&nd->root.dentry->d_seq);
-		} while (read_seqcount_retry(&fs->seq, seq));
-	}
+	do {
+		seq = read_seqcount_begin(&fs->seq);
+		nd->root = fs->root;
+		res = __read_seqcount_begin(&nd->root.dentry->d_seq);
+	} while (read_seqcount_retry(&fs->seq, seq));
+	return res;
 }
 
 static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link)
@@ -582,7 +580,8 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l
 		goto fail;
 
 	if (*link == '/') {
-		set_root(nd);
+		if (!nd->root.mnt)
+			set_root(nd);
 		path_put(&nd->path);
 		nd->path = nd->root;
 		path_get(&nd->root);
@@ -912,22 +911,11 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
 	return true;
 }
 
-static void follow_mount_rcu(struct nameidata *nd)
-{
-	while (d_mountpoint(nd->path.dentry)) {
-		struct vfsmount *mounted;
-		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1);
-		if (!mounted)
-			break;
-		nd->path.mnt = mounted;
-		nd->path.dentry = mounted->mnt_root;
-		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
-	}
-}
-
 static int follow_dotdot_rcu(struct nameidata *nd)
 {
-	set_root_rcu(nd);
+	struct inode *inode = nd->inode;
+	if (!nd->root.mnt)
+		set_root_rcu(nd);
 
 	while (1) {
 		if (nd->path.dentry == nd->root.dentry &&
@@ -939,6 +927,7 @@ static int follow_dotdot_rcu(struct nameidata *nd)
 			struct dentry *parent = old->d_parent;
 			unsigned seq;
 
+			inode = parent->d_inode;
 			seq = read_seqcount_begin(&parent->d_seq);
 			if (read_seqcount_retry(&old->d_seq, nd->seq))
 				goto failed;
@@ -948,10 +937,20 @@ static int follow_dotdot_rcu(struct nameidata *nd)
 		}
 		if (!follow_up_rcu(&nd->path))
 			break;
+		inode = nd->path.dentry->d_inode;
 		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
 	}
-	follow_mount_rcu(nd);
-	nd->inode = nd->path.dentry->d_inode;
+	while (d_mountpoint(nd->path.dentry)) {
+		struct vfsmount *mounted;
+		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1);
+		if (!mounted)
+			break;
+		nd->path.mnt = mounted;
+		nd->path.dentry = mounted->mnt_root;
+		inode = nd->path.dentry->d_inode;
+		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
+	}
+	nd->inode = inode;
 	return 0;
 
 failed:
@@ -1030,7 +1029,8 @@ static void follow_mount(struct path *path)
 
 static void follow_dotdot(struct nameidata *nd)
 {
-	set_root(nd);
+	if (!nd->root.mnt)
+		set_root(nd);
 
 	while(1) {
 		struct dentry *old = nd->path.dentry;
@@ -1504,7 +1504,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 		if (flags & LOOKUP_RCU) {
 			br_read_lock(vfsmount_lock);
 			rcu_read_lock();
-			set_root_rcu(nd);
+			nd->seq = set_root_rcu(nd);
 		} else {
 			set_root(nd);
 			path_get(&nd->root);
@@ -1560,7 +1560,14 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 	}
 
 	nd->inode = nd->path.dentry->d_inode;
-	return 0;
+	if (!(flags & LOOKUP_RCU))
+		return 0;
+	if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
+		return 0;
+	if (!(nd->flags & LOOKUP_ROOT))
+		nd->root.mnt = NULL;
+	rcu_read_unlock();
+	return -ECHILD;
 
 fput_fail:
 	fput_light(file, fput_needed);