namei: stash dfd and name into nameidata

fewer arguments to pass around...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 14aaf00f8ee772582d1b851e4bb1da40170f8858..970456fc9ea8e414ffd433ebc7a22eaa87d9e020 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -498,6 +498,8 @@ struct nameidata {
        struct qstr     last;
        struct path     root;
        struct inode    *inode; /* path.dentry.d_inode */
+       struct filename *name;
+       int             dfd;
        unsigned int    flags;
        unsigned        seq, m_seq, root_seq;
        int             last_type;
@@ -512,10 +514,13 @@ struct nameidata {
        } *stack, internal[EMBEDDED_LEVELS];
 };
 
-static struct nameidata *set_nameidata(struct nameidata *p)
+static struct nameidata *set_nameidata(struct nameidata *p, int dfd,
+                                       struct filename *name)
 {
        struct nameidata *old = current->nameidata;
        p->stack = p->internal;
+       p->dfd = dfd;
+       p->name = name;
        p->total_link_count = old ? old->total_link_count : 0;
        current->nameidata = p;
        return old;
@@ -1954,11 +1959,10 @@ OK:
        }
 }
 
-static const char *path_init(int dfd, const struct filename *name,
-                            unsigned int flags, struct nameidata *nd)
+static const char *path_init(struct nameidata *nd, unsigned flags)
 {
        int retval = 0;
-       const char *s = name->name;
+       const char *s = nd->name->name;
 
        nd->last_type = LAST_ROOT; /* if there are only slashes... */
        nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
@@ -1999,7 +2003,7 @@ static const char *path_init(int dfd, const struct filename *name,
                        path_get(&nd->root);
                }
                nd->path = nd->root;
-       } else if (dfd == AT_FDCWD) {
+       } else if (nd->dfd == AT_FDCWD) {
                if (flags & LOOKUP_RCU) {
                        struct fs_struct *fs = current->fs;
                        unsigned seq;
@@ -2016,7 +2020,7 @@ static const char *path_init(int dfd, const struct filename *name,
                }
        } else {
                /* Caller must check execute permissions on the starting path component */
-               struct fd f = fdget_raw(dfd);
+               struct fd f = fdget_raw(nd->dfd);
                struct dentry *dentry;
 
                if (!f.file)
@@ -2082,10 +2086,9 @@ static inline int lookup_last(struct nameidata *nd)
 }
 
 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
-static int path_lookupat(int dfd, const struct filename *name, unsigned flags,
-                        struct nameidata *nd, struct path *path)
+static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path)
 {
-       const char *s = path_init(dfd, name, flags, nd);
+       const char *s = path_init(nd, flags);
        int err;
 
        if (IS_ERR(s))
@@ -2120,17 +2123,16 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
        struct nameidata nd, *saved_nd;
        if (IS_ERR(name))
                return PTR_ERR(name);
-       saved_nd = set_nameidata(&nd);
+       saved_nd = set_nameidata(&nd, dfd, name);
        if (unlikely(root)) {
                nd.root = *root;
                flags |= LOOKUP_ROOT;
        }
-       retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, &nd, path);
+       retval = path_lookupat(&nd, flags | LOOKUP_RCU, path);
        if (unlikely(retval == -ECHILD))
-               retval = path_lookupat(dfd, name, flags, &nd, path);
+               retval = path_lookupat(&nd, flags, path);
        if (unlikely(retval == -ESTALE))
-               retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL,
-                                      &nd, path);
+               retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path);
 
        if (likely(!retval))
                audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
@@ -2140,11 +2142,10 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
 }
 
 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
-static int path_parentat(int dfd, const struct filename *name,
-                               unsigned int flags, struct nameidata *nd,
+static int path_parentat(struct nameidata *nd, unsigned flags,
                                struct path *parent)
 {
-       const char *s = path_init(dfd, name, flags, nd);
+       const char *s = path_init(nd, flags);
        int err;
        if (IS_ERR(s))
                return PTR_ERR(s);
@@ -2169,13 +2170,12 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
 
        if (IS_ERR(name))
                return name;
-       saved_nd = set_nameidata(&nd);
-       retval = path_parentat(dfd, name, flags | LOOKUP_RCU, &nd, parent);
+       saved_nd = set_nameidata(&nd, dfd, name);
+       retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
        if (unlikely(retval == -ECHILD))
-               retval = path_parentat(dfd, name, flags, &nd, parent);
+               retval = path_parentat(&nd, flags, parent);
        if (unlikely(retval == -ESTALE))
-               retval = path_parentat(dfd, name, flags | LOOKUP_REVAL,
-                                       &nd, parent);
+               retval = path_parentat(&nd, flags | LOOKUP_REVAL, parent);
        if (likely(!retval)) {
                *last = nd.last;
                *type = nd.last_type;
@@ -2415,19 +2415,17 @@ done:
 
 /**
  * path_mountpoint - look up a path to be umounted
- * @dfd:       directory file descriptor to start walk from
- * @name:      full pathname to walk
- * @path:      pointer to container for result
+ * @nameidata: lookup context
  * @flags:     lookup flags
+ * @path:      pointer to container for result
  *
  * Look up the given name, but don't attempt to revalidate the last component.
  * Returns 0 and "path" will be valid on success; Returns error otherwise.
  */
 static int
-path_mountpoint(int dfd, const struct filename *name, struct path *path,
-               struct nameidata *nd, unsigned int flags)
+path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
 {
-       const char *s = path_init(dfd, name, flags, nd);
+       const char *s = path_init(nd, flags);
        int err;
        if (IS_ERR(s))
                return PTR_ERR(s);
@@ -2451,12 +2449,12 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
        int error;
        if (IS_ERR(name))
                return PTR_ERR(name);
-       saved = set_nameidata(&nd);
-       error = path_mountpoint(dfd, name, path, &nd, flags | LOOKUP_RCU);
+       saved = set_nameidata(&nd, dfd, name);
+       error = path_mountpoint(&nd, flags | LOOKUP_RCU, path);
        if (unlikely(error == -ECHILD))
-               error = path_mountpoint(dfd, name, path, &nd, flags);
+               error = path_mountpoint(&nd, flags, path);
        if (unlikely(error == -ESTALE))
-               error = path_mountpoint(dfd, name, path, &nd, flags | LOOKUP_REVAL);
+               error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
        if (likely(!error))
                audit_inode(name, path->dentry, 0);
        restore_nameidata(saved);
@@ -3217,8 +3215,7 @@ stale_open:
        goto retry_lookup;
 }
 
-static int do_tmpfile(int dfd, struct filename *pathname,
-               struct nameidata *nd, int flags,
+static int do_tmpfile(struct nameidata *nd, unsigned flags,
                const struct open_flags *op,
                struct file *file, int *opened)
 {
@@ -3226,8 +3223,7 @@ static int do_tmpfile(int dfd, struct filename *pathname,
        struct dentry *child;
        struct inode *dir;
        struct path path;
-       int error = path_lookupat(dfd, pathname,
-                                 flags | LOOKUP_DIRECTORY, nd, &path);
+       int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
        if (unlikely(error))
                return error;
        error = mnt_want_write(path.mnt);
@@ -3252,7 +3248,7 @@ static int do_tmpfile(int dfd, struct filename *pathname,
        error = dir->i_op->tmpfile(dir, child, op->mode);
        if (error)
                goto out2;
-       audit_inode(pathname, child, 0);
+       audit_inode(nd->name, child, 0);
        /* Don't check for other permissions, the inode was just created */
        error = may_open(&path, MAY_OPEN, op->open_flag);
        if (error)
@@ -3277,8 +3273,8 @@ out:
        return error;
 }
 
-static struct file *path_openat(int dfd, struct filename *pathname,
-               struct nameidata *nd, const struct open_flags *op, int flags)
+static struct file *path_openat(struct nameidata *nd,
+                       const struct open_flags *op, unsigned flags)
 {
        const char *s;
        struct file *file;
@@ -3292,17 +3288,17 @@ static struct file *path_openat(int dfd, struct filename *pathname,
        file->f_flags = op->open_flag;
 
        if (unlikely(file->f_flags & __O_TMPFILE)) {
-               error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened);
+               error = do_tmpfile(nd, flags, op, file, &opened);
                goto out2;
        }
 
-       s = path_init(dfd, pathname, flags, nd);
+       s = path_init(nd, flags);
        if (IS_ERR(s)) {
                put_filp(file);
                return ERR_CAST(s);
        }
        while (!(error = link_path_walk(s, nd)) &&
-               (error = do_last(nd, file, op, &opened, pathname)) > 0) {
+               (error = do_last(nd, file, op, &opened, nd->name)) > 0) {
                nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
                s = trailing_symlink(nd);
                if (IS_ERR(s)) {
@@ -3331,15 +3327,15 @@ out2:
 struct file *do_filp_open(int dfd, struct filename *pathname,
                const struct open_flags *op)
 {
-       struct nameidata nd, *saved_nd = set_nameidata(&nd);
+       struct nameidata nd, *saved_nd = set_nameidata(&nd, dfd, pathname);
        int flags = op->lookup_flags;
        struct file *filp;
 
-       filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU);
+       filp = path_openat(&nd, op, flags | LOOKUP_RCU);
        if (unlikely(filp == ERR_PTR(-ECHILD)))
-               filp = path_openat(dfd, pathname, &nd, op, flags);
+               filp = path_openat(&nd, op, flags);
        if (unlikely(filp == ERR_PTR(-ESTALE)))
-               filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_REVAL);
+               filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
        restore_nameidata(saved_nd);
        return filp;
 }
@@ -3362,12 +3358,12 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
        if (unlikely(IS_ERR(filename)))
                return ERR_CAST(filename);
 
-       saved_nd = set_nameidata(&nd);
-       file = path_openat(-1, filename, &nd, op, flags | LOOKUP_RCU);
+       saved_nd = set_nameidata(&nd, -1, filename);
+       file = path_openat(&nd, op, flags | LOOKUP_RCU);
        if (unlikely(file == ERR_PTR(-ECHILD)))
-               file = path_openat(-1, filename, &nd, op, flags);
+               file = path_openat(&nd, op, flags);
        if (unlikely(file == ERR_PTR(-ESTALE)))
-               file = path_openat(-1, filename, &nd, op, flags | LOOKUP_REVAL);
+               file = path_openat(&nd, op, flags | LOOKUP_REVAL);
        restore_nameidata(saved_nd);
        putname(filename);
        return file;