1 files changed, 29 insertions, 25 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 187cacf..1004966 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -34,6 +34,7 @@
 #include <linux/device_cgroup.h>
 #include <linux/fs_struct.h>
 #include <linux/posix_acl.h>
+#include <linux/hash.h>
 #include <asm/uaccess.h>
 
 #include "internal.h"
@@ -321,10 +322,11 @@ int generic_permission(struct inode *inode, int mask)
 
 	if (S_ISDIR(inode->i_mode)) {
 		/* DACs are overridable for directories */
-		if (inode_capable(inode, CAP_DAC_OVERRIDE))
+		if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE))
 			return 0;
 		if (!(mask & MAY_WRITE))
-			if (inode_capable(inode, CAP_DAC_READ_SEARCH))
+			if (capable_wrt_inode_uidgid(inode,
+						     CAP_DAC_READ_SEARCH))
 				return 0;
 		return -EACCES;
 	}
@@ -334,7 +336,7 @@ int generic_permission(struct inode *inode, int mask)
 	 * at least one exec bit set.
 	 */
 	if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO))
-		if (inode_capable(inode, CAP_DAC_OVERRIDE))
+		if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE))
 			return 0;
 
 	/*
@@ -342,7 +344,7 @@ int generic_permission(struct inode *inode, int mask)
 	 */
 	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 	if (mask == MAY_READ)
-		if (inode_capable(inode, CAP_DAC_READ_SEARCH))
+		if (capable_wrt_inode_uidgid(inode, CAP_DAC_READ_SEARCH))
 			return 0;
 
 	return -EACCES;
@@ -640,24 +642,22 @@ 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 void path_put_conditional(struct path *path, struct nameidata *nd)
@@ -857,7 +857,8 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
 			return PTR_ERR(s);
 		}
 		if (*s == '/') {
-			set_root(nd);
+			if (!nd->root.mnt)
+				set_root(nd);
 			path_put(&nd->path);
 			nd->path = nd->root;
 			path_get(&nd->root);
@@ -1143,7 +1144,8 @@ static void follow_mount_rcu(struct nameidata *nd)
 
 static int follow_dotdot_rcu(struct nameidata *nd)
 {
-	set_root_rcu(nd);
+	if (!nd->root.mnt)
+		set_root_rcu(nd);
 
 	while (1) {
 		if (nd->path.dentry == nd->root.dentry &&
@@ -1245,7 +1247,8 @@ 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;
@@ -1660,8 +1663,7 @@ static inline int can_lookup(struct inode *inode)
 
 static inline unsigned int fold_hash(unsigned long hash)
 {
-	hash += hash >> (8*sizeof(int));
-	return hash;
+	return hash_64(hash, 32);
 }
 
 #else	/* 32-bit case */
@@ -1875,7 +1877,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 	if (*name=='/') {
 		if (flags & LOOKUP_RCU) {
 			lock_rcu_walk();
-			set_root_rcu(nd);
+			nd->seq = set_root_rcu(nd);
 		} else {
 			set_root(nd);
 			path_get(&nd->root);
@@ -2280,9 +2282,10 @@ done:
 		goto out;
 	}
 	path->dentry = dentry;
-	path->mnt = mntget(nd->path.mnt);
+	path->mnt = nd->path.mnt;
 	if (should_follow_link(dentry->d_inode, nd->flags & LOOKUP_FOLLOW))
 		return 1;
+	mntget(path->mnt);
 	follow_mount(path);
 	error = 0;
 out:
@@ -2404,7 +2407,7 @@ static inline int check_sticky(struct inode *dir, struct inode *inode)
 		return 0;
 	if (uid_eq(dir->i_uid, fsuid))
 		return 0;
-	return !inode_capable(inode, CAP_FOWNER);
+	return !capable_wrt_inode_uidgid(inode, CAP_FOWNER);
 }
 
 /*
@@ -3156,7 +3159,8 @@ static int do_tmpfile(int dfd, struct filename *pathname,
 	if (error)
 		goto out2;
 	audit_inode(pathname, nd->path.dentry, 0);
-	error = may_open(&nd->path, op->acc_mode, op->open_flag);
+	/* Don't check for other permissions, the inode was just created */
+	error = may_open(&nd->path, MAY_OPEN, op->open_flag);
 	if (error)
 		goto out2;
 	file->f_path.mnt = nd->path.mnt;