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Date: Wed, 13 May 2015 23:26:10 +0100
From: Al Viro <viro@...IV.linux.org.uk>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Neil Brown <neilb@...e.de>, Christoph Hellwig <hch@...radead.org>,
linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: [PATCH 16/21] namei: stash dfd and name into nameidata
From: Al Viro <viro@...iv.linux.org.uk>
fewer arguments to pass around...
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
fs/namei.c | 96 ++++++++++++++++++++++++++++++--------------------------------
1 file changed, 46 insertions(+), 50 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 59a4662..0c39113 100644
--- 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;
@@ -1953,11 +1958,10 @@ 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;
@@ -1997,7 +2001,7 @@ 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;
@@ -2014,7 +2018,7 @@ 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)
@@ -2080,10 +2084,9 @@ 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))
@@ -2118,17 +2121,16 @@ 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);
@@ -2138,11 +2140,10 @@ 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);
@@ -2167,13 +2168,12 @@ 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;
@@ -2413,19 +2413,17 @@ 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);
@@ -2449,12 +2447,12 @@ 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);
@@ -3215,8 +3213,7 @@ 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)
{
@@ -3224,8 +3221,7 @@ 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);
@@ -3250,7 +3246,7 @@ 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)
@@ -3275,8 +3271,8 @@ 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;
@@ -3290,17 +3286,17 @@ 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)) {
@@ -3329,15 +3325,15 @@ 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;
}
@@ -3360,12 +3356,12 @@ 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;
--
2.1.4
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