nfsd4: reshuffle lease-setting code to allow reuse

[safe/jmp/linux-2.6] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 68921d9..a4855af 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -232,6 +232,7 @@ int generic_permission(struct inode *inode, int mask,
        /*
         * Searching includes executable on directories, else just read.
         */
+       mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
        if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
                if (capable(CAP_DAC_READ_SEARCH))
                        return 0;
@@ -560,6 +561,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
                dget(dentry);
        }
        mntget(path->mnt);
+       nd->last_type = LAST_BIND;
        cookie = dentry->d_inode->i_op->follow_link(dentry, nd);
        error = PTR_ERR(cookie);
        if (!IS_ERR(cookie)) {
@@ -821,6 +823,17 @@ fail:
 }
 
 /*
+ * This is a temporary kludge to deal with "automount" symlinks; proper
+ * solution is to trigger them on follow_mount(), so that do_lookup()
+ * would DTRT.  To be killed before 2.6.34-final.
+ */
+static inline int follow_on_final(struct inode *inode, unsigned lookup_flags)
+{
+       return inode && unlikely(inode->i_op->follow_link) &&
+               ((lookup_flags & LOOKUP_FOLLOW) || S_ISDIR(inode->i_mode));
+}
+
+/*
  * Name resolution.
  * This is the basic name resolution function, turning a pathname into
  * the final dentry. We expect 'base' to be positive and a directory.
@@ -940,8 +953,7 @@ last_component:
                if (err)
                        break;
                inode = next.dentry->d_inode;
-               if ((lookup_flags & LOOKUP_FOLLOW)
-                   && inode && inode->i_op->follow_link) {
+               if (follow_on_final(inode, lookup_flags)) {
                        err = do_follow_link(&next, nd);
                        if (err)
                                goto return_err;
@@ -1602,11 +1614,12 @@ struct file *do_filp_open(int dfd, const char *pathname,
        struct file *filp;
        struct nameidata nd;
        int error;
-       struct path path, save;
+       struct path path;
        struct dentry *dir;
        int count = 0;
        int will_truncate;
        int flag = open_to_namei_flags(open_flag);
+       int force_reval = 0;
 
        /*
         * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only
@@ -1618,7 +1631,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
                open_flag |= O_DSYNC;
 
        if (!acc_mode)
-               acc_mode = MAY_OPEN | ACC_MODE(flag);
+               acc_mode = MAY_OPEN | ACC_MODE(open_flag);
 
        /* O_TRUNC implies we need access checks for write permissions */
        if (flag & O_TRUNC)
@@ -1658,9 +1671,12 @@ struct file *do_filp_open(int dfd, const char *pathname,
        /*
         * Create - we need to know the parent.
         */
+reval:
        error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
        if (error)
                return ERR_PTR(error);
+       if (force_reval)
+               nd.flags |= LOOKUP_REVAL;
        error = path_walk(pathname, &nd);
        if (error) {
                if (nd.root.mnt)
@@ -1730,8 +1746,7 @@ do_last:
                if (nd.root.mnt)
                        path_put(&nd.root);
                if (!IS_ERR(filp)) {
-                       error = ima_path_check(&filp->f_path, filp->f_mode &
-                                      (MAY_READ | MAY_WRITE | MAY_EXEC));
+                       error = ima_file_check(filp, acc_mode);
                        if (error) {
                                fput(filp);
                                filp = ERR_PTR(error);
@@ -1791,8 +1806,7 @@ ok:
        }
        filp = nameidata_to_filp(&nd);
        if (!IS_ERR(filp)) {
-               error = ima_path_check(&filp->f_path, filp->f_mode &
-                              (MAY_READ | MAY_WRITE | MAY_EXEC));
+               error = ima_file_check(filp, acc_mode);
                if (error) {
                        fput(filp);
                        filp = ERR_PTR(error);
@@ -1852,17 +1866,7 @@ do_link:
        error = security_inode_follow_link(path.dentry, &nd);
        if (error)
                goto exit_dput;
-       save = nd.path;
-       path_get(&save);
        error = __do_follow_link(&path, &nd);
-       if (error == -ESTALE) {
-               /* nd.path had been dropped */
-               nd.path = save;
-               path_get(&nd.path);
-               nd.flags |= LOOKUP_REVAL;
-               error = __do_follow_link(&path, &nd);
-       }
-       path_put(&save);
        path_put(&path);
        if (error) {
                /* Does someone understand code flow here? Or it is only
@@ -1872,6 +1876,10 @@ do_link:
                release_open_intent(&nd);
                if (nd.root.mnt)
                        path_put(&nd.root);
+               if (error == -ESTALE && !force_reval) {
+                       force_reval = 1;
+                       goto reval;
+               }
                return ERR_PTR(error);
        }
        nd.flags &= ~LOOKUP_PARENT;