From c8a53ee5ee4fcab5ee252f61a69609b65e5e74b8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 12 May 2015 18:43:07 -0400 Subject: [PATCH] namei: stash dfd and name into nameidata fewer arguments to pass around... Signed-off-by: Al Viro --- fs/namei.c | 96 ++++++++++++++++++++++++++---------------------------- 1 file changed, 46 insertions(+), 50 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 14aaf00f8ee7..970456fc9ea8 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; @@ -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; -- 2.20.1