} *stack, internal[EMBEDDED_LEVELS];
struct filename *name;
struct nameidata *saved;
- struct inode *link_inode;
unsigned root_seq;
int dfd;
} __randomize_layout;
return 0;
}
-static void path_put_conditional(struct path *path, struct nameidata *nd)
-{
- dput(path->dentry);
- if (path->mnt != nd->path.mnt)
- mntput(path->mnt);
-}
-
static inline void path_to_nameidata(const struct path *path,
struct nameidata *nd)
{
*
* Returns 0 if following the symlink is allowed, -ve on error.
*/
-static inline int may_follow_link(struct nameidata *nd)
+static inline int may_follow_link(struct nameidata *nd, const struct inode *inode)
{
- const struct inode *inode;
const struct inode *parent;
kuid_t puid;
return 0;
/* Allowed if owner and follower match. */
- inode = nd->link_inode;
if (uid_eq(current_cred()->fsuid, inode->i_uid))
return 0;
return 0;
}
-static __always_inline
-const char *get_link(struct nameidata *nd)
-{
- struct saved *last = nd->stack + nd->depth - 1;
- struct dentry *dentry = last->link.dentry;
- struct inode *inode = nd->link_inode;
- int error;
- const char *res;
-
- if (unlikely(nd->flags & LOOKUP_NO_SYMLINKS))
- return ERR_PTR(-ELOOP);
-
- if (!(nd->flags & LOOKUP_RCU)) {
- touch_atime(&last->link);
- cond_resched();
- } else if (atime_needs_update(&last->link, inode)) {
- if (unlikely(unlazy_walk(nd)))
- return ERR_PTR(-ECHILD);
- touch_atime(&last->link);
- }
-
- error = security_inode_follow_link(dentry, inode,
- nd->flags & LOOKUP_RCU);
- if (unlikely(error))
- return ERR_PTR(error);
-
- nd->last_type = LAST_BIND;
- res = READ_ONCE(inode->i_link);
- if (!res) {
- const char * (*get)(struct dentry *, struct inode *,
- struct delayed_call *);
- get = inode->i_op->get_link;
- if (nd->flags & LOOKUP_RCU) {
- res = get(NULL, inode, &last->done);
- if (res == ERR_PTR(-ECHILD)) {
- if (unlikely(unlazy_walk(nd)))
- return ERR_PTR(-ECHILD);
- res = get(dentry, inode, &last->done);
- }
- } else {
- res = get(dentry, inode, &last->done);
- }
- if (IS_ERR_OR_NULL(res))
- return res;
- }
- if (*res == '/') {
- error = nd_jump_root(nd);
- if (unlikely(error))
- return ERR_PTR(error);
- while (unlikely(*++res == '/'))
- ;
- }
- if (!*res)
- res = NULL;
- return res;
-}
-
/*
* follow_up - Find the mountpoint of path's vfsmount
*
* - return -EISDIR to tell follow_managed() to stop and return the path we
* were called with.
*/
-static int follow_automount(struct path *path, struct nameidata *nd,
- bool *need_mntput)
+static int follow_automount(struct path *path, int *count, unsigned lookup_flags)
{
- struct vfsmount *mnt;
- int err;
-
- if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
- return -EREMOTE;
+ struct dentry *dentry = path->dentry;
/* We don't want to mount if someone's just doing a stat -
* unless they're stat'ing a directory and appended a '/' to
* as being automount points. These will need the attentions
* of the daemon to instantiate them before they can be used.
*/
- if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
+ if (!(lookup_flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) &&
- path->dentry->d_inode)
+ dentry->d_inode)
return -EISDIR;
- nd->total_link_count++;
- if (nd->total_link_count >= 40)
+ if (count && (*count)++ >= MAXSYMLINKS)
return -ELOOP;
- mnt = path->dentry->d_op->d_automount(path);
- if (IS_ERR(mnt)) {
- /*
- * The filesystem is allowed to return -EISDIR here to indicate
- * it doesn't want to automount. For instance, autofs would do
- * this so that its userspace daemon can mount on this dentry.
- *
- * However, we can only permit this if it's a terminal point in
- * the path being looked up; if it wasn't then the remainder of
- * the path is inaccessible and we should say so.
- */
- if (PTR_ERR(mnt) == -EISDIR && (nd->flags & LOOKUP_PARENT))
- return -EREMOTE;
- return PTR_ERR(mnt);
- }
-
- if (!mnt) /* mount collision */
- return 0;
-
- if (!*need_mntput) {
- /* lock_mount() may release path->mnt on error */
- mntget(path->mnt);
- *need_mntput = true;
- }
- err = finish_automount(mnt, path);
-
- switch (err) {
- case -EBUSY:
- /* Someone else made a mount here whilst we were busy */
- return 0;
- case 0:
- path_put(path);
- path->mnt = mnt;
- path->dentry = dget(mnt->mnt_root);
- return 0;
- default:
- return err;
- }
-
+ return finish_automount(dentry->d_op->d_automount(path), path);
}
/*
/* Handle an automount point */
if (flags & DCACHE_NEED_AUTOMOUNT) {
- ret = follow_automount(path, nd, &need_mntput);
+ ret = follow_automount(path, &nd->total_link_count,
+ nd->flags);
if (ret < 0)
break;
continue;
ret = 1;
if (ret > 0 && unlikely(d_flags_negative(flags)))
ret = -ENOENT;
- if (unlikely(ret < 0))
- path_put_conditional(path, nd);
+ if (unlikely(ret < 0)) {
+ dput(path->dentry);
+ if (path->mnt != nd->path.mnt)
+ mntput(path->mnt);
+ }
return ret;
}
}
EXPORT_SYMBOL(follow_down_one);
-static inline int managed_dentry_rcu(const struct path *path)
-{
- return (path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) ?
- path->dentry->d_op->d_manage(path, true) : 0;
-}
-
/*
* Try to skip to top of mountpoint pile in rcuwalk mode. Fail if
* we meet a managed dentry that would need blocking.
static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
struct inode **inode, unsigned *seqp)
{
+ struct dentry *dentry = path->dentry;
+ unsigned int flags = dentry->d_flags;
+
+ if (likely(!(flags & DCACHE_MANAGED_DENTRY)))
+ return true;
+
+ if (unlikely(nd->flags & LOOKUP_NO_XDEV))
+ return false;
+
for (;;) {
- struct mount *mounted;
/*
* Don't forget we might have a non-mountpoint managed dentry
* that wants to block transit.
*/
- switch (managed_dentry_rcu(path)) {
- case -ECHILD:
- default:
- return false;
- case -EISDIR:
- return true;
- case 0:
- break;
+ if (unlikely(flags & DCACHE_MANAGE_TRANSIT)) {
+ int res = dentry->d_op->d_manage(path, true);
+ if (res)
+ return res == -EISDIR;
+ flags = dentry->d_flags;
}
- if (!d_mountpoint(path->dentry))
- return !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT);
+ if (flags & DCACHE_MOUNTED) {
+ struct mount *mounted = __lookup_mnt(path->mnt, dentry);
+ if (mounted) {
+ path->mnt = &mounted->mnt;
+ dentry = path->dentry = mounted->mnt.mnt_root;
+ nd->flags |= LOOKUP_JUMPED;
+ *seqp = read_seqcount_begin(&dentry->d_seq);
+ *inode = dentry->d_inode;
+ /*
+ * We don't need to re-check ->d_seq after this
+ * ->d_inode read - there will be an RCU delay
+ * between mount hash removal and ->mnt_root
+ * becoming unpinned.
+ */
+ flags = dentry->d_flags;
+ continue;
+ }
+ if (read_seqretry(&mount_lock, nd->m_seq))
+ return false;
+ }
+ return !(flags & DCACHE_NEED_AUTOMOUNT);
+ }
+}
- mounted = __lookup_mnt(path->mnt, path->dentry);
- if (!mounted)
- break;
- if (unlikely(nd->flags & LOOKUP_NO_XDEV))
- return false;
- path->mnt = &mounted->mnt;
- path->dentry = mounted->mnt.mnt_root;
- nd->flags |= LOOKUP_JUMPED;
- *seqp = read_seqcount_begin(&path->dentry->d_seq);
- /*
- * Update the inode too. We don't need to re-check the
- * dentry sequence number here after this d_inode read,
- * because a mount-point is always pinned.
- */
- *inode = path->dentry->d_inode;
+static inline int handle_mounts(struct nameidata *nd, struct dentry *dentry,
+ struct path *path, struct inode **inode,
+ unsigned int *seqp)
+{
+ int ret;
+
+ path->mnt = nd->path.mnt;
+ path->dentry = dentry;
+ if (nd->flags & LOOKUP_RCU) {
+ unsigned int seq = *seqp;
+ if (unlikely(!*inode))
+ return -ENOENT;
+ if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
+ return 1;
+ if (unlazy_child(nd, dentry, seq))
+ return -ECHILD;
+ // *path might've been clobbered by __follow_mount_rcu()
+ path->mnt = nd->path.mnt;
+ path->dentry = dentry;
+ }
+ ret = follow_managed(path, nd);
+ if (likely(ret >= 0)) {
+ *inode = d_backing_inode(path->dentry);
+ *seqp = 0; /* out of RCU mode, so the value doesn't matter */
}
- return !read_seqretry(&mount_lock, nd->m_seq) &&
- !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT);
+ return ret;
}
static int follow_dotdot_rcu(struct nameidata *nd)
return dentry;
}
-static int lookup_fast(struct nameidata *nd,
- struct path *path, struct inode **inode,
- unsigned *seqp)
+static struct dentry *lookup_fast(struct nameidata *nd,
+ struct inode **inode,
+ unsigned *seqp)
{
- struct vfsmount *mnt = nd->path.mnt;
struct dentry *dentry, *parent = nd->path.dentry;
int status = 1;
- int err;
/*
* Rename seqlock is not required here because in the off chance
*/
if (nd->flags & LOOKUP_RCU) {
unsigned seq;
- bool negative;
dentry = __d_lookup_rcu(parent, &nd->last, &seq);
if (unlikely(!dentry)) {
if (unlazy_walk(nd))
- return -ECHILD;
- return 0;
+ return ERR_PTR(-ECHILD);
+ return NULL;
}
/*
* the dentry name information from lookup.
*/
*inode = d_backing_inode(dentry);
- negative = d_is_negative(dentry);
if (unlikely(read_seqcount_retry(&dentry->d_seq, seq)))
- return -ECHILD;
+ return ERR_PTR(-ECHILD);
/*
* This sequence count validates that the parent had no
* enough, we can use __read_seqcount_retry here.
*/
if (unlikely(__read_seqcount_retry(&parent->d_seq, nd->seq)))
- return -ECHILD;
+ return ERR_PTR(-ECHILD);
*seqp = seq;
status = d_revalidate(dentry, nd->flags);
- if (likely(status > 0)) {
- /*
- * Note: do negative dentry check after revalidation in
- * case that drops it.
- */
- if (unlikely(negative))
- return -ENOENT;
- path->mnt = mnt;
- path->dentry = dentry;
- if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
- return 1;
- }
+ if (likely(status > 0))
+ return dentry;
if (unlazy_child(nd, dentry, seq))
- return -ECHILD;
+ return ERR_PTR(-ECHILD);
if (unlikely(status == -ECHILD))
/* we'd been told to redo it in non-rcu mode */
status = d_revalidate(dentry, nd->flags);
} else {
dentry = __d_lookup(parent, &nd->last);
if (unlikely(!dentry))
- return 0;
+ return NULL;
status = d_revalidate(dentry, nd->flags);
}
if (unlikely(status <= 0)) {
if (!status)
d_invalidate(dentry);
dput(dentry);
- return status;
+ return ERR_PTR(status);
}
-
- path->mnt = mnt;
- path->dentry = dentry;
- err = follow_managed(path, nd);
- if (likely(err > 0))
- *inode = d_backing_inode(path->dentry);
- return err;
+ return dentry;
}
/* Fast lookup failed, do it the slow way */
return 0;
}
-static int pick_link(struct nameidata *nd, struct path *link,
- struct inode *inode, unsigned seq)
+enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4};
+
+static const char *pick_link(struct nameidata *nd, struct path *link,
+ struct inode *inode, unsigned seq, int flags)
{
- int error;
struct saved *last;
+ const char *res;
+ int error;
+
if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
path_to_nameidata(link, nd);
- return -ELOOP;
+ return ERR_PTR(-ELOOP);
}
if (!(nd->flags & LOOKUP_RCU)) {
if (link->mnt == nd->path.mnt)
}
if (error) {
path_put(link);
- return error;
+ return ERR_PTR(error);
}
}
last = nd->stack + nd->depth++;
last->link = *link;
clear_delayed_call(&last->done);
- nd->link_inode = inode;
last->seq = seq;
- return 1;
-}
-enum {WALK_FOLLOW = 1, WALK_MORE = 2};
+ if (flags & WALK_TRAILING) {
+ error = may_follow_link(nd, inode);
+ if (unlikely(error))
+ return ERR_PTR(error);
+ }
+
+ if (unlikely(nd->flags & LOOKUP_NO_SYMLINKS))
+ return ERR_PTR(-ELOOP);
+
+ if (!(nd->flags & LOOKUP_RCU)) {
+ touch_atime(&last->link);
+ cond_resched();
+ } else if (atime_needs_update(&last->link, inode)) {
+ if (unlikely(unlazy_walk(nd)))
+ return ERR_PTR(-ECHILD);
+ touch_atime(&last->link);
+ }
+
+ error = security_inode_follow_link(link->dentry, inode,
+ nd->flags & LOOKUP_RCU);
+ if (unlikely(error))
+ return ERR_PTR(error);
+
+ res = READ_ONCE(inode->i_link);
+ if (!res) {
+ const char * (*get)(struct dentry *, struct inode *,
+ struct delayed_call *);
+ get = inode->i_op->get_link;
+ if (nd->flags & LOOKUP_RCU) {
+ res = get(NULL, inode, &last->done);
+ if (res == ERR_PTR(-ECHILD)) {
+ if (unlikely(unlazy_walk(nd)))
+ return ERR_PTR(-ECHILD);
+ res = get(link->dentry, inode, &last->done);
+ }
+ } else {
+ res = get(link->dentry, inode, &last->done);
+ }
+ if (!res)
+ goto all_done;
+ if (IS_ERR(res))
+ return res;
+ }
+ if (*res == '/') {
+ error = nd_jump_root(nd);
+ if (unlikely(error))
+ return ERR_PTR(error);
+ while (unlikely(*++res == '/'))
+ ;
+ }
+ if (*res)
+ return res;
+all_done: // pure jump
+ put_link(nd);
+ return NULL;
+}
/*
* Do we need to follow links? We _really_ want to be able
* so we keep a cache of "no, this doesn't need follow_link"
* for the common case.
*/
-static inline int step_into(struct nameidata *nd, struct path *path,
- int flags, struct inode *inode, unsigned seq)
+static const char *step_into(struct nameidata *nd, int flags,
+ struct dentry *dentry, struct inode *inode, unsigned seq)
{
- if (!(flags & WALK_MORE) && nd->depth)
- put_link(nd);
- if (likely(!d_is_symlink(path->dentry)) ||
- !(flags & WALK_FOLLOW || nd->flags & LOOKUP_FOLLOW)) {
+ struct path path;
+ int err = handle_mounts(nd, dentry, &path, &inode, &seq);
+
+ if (err < 0)
+ return ERR_PTR(err);
+ if (likely(!d_is_symlink(path.dentry)) ||
+ ((flags & WALK_TRAILING) && !(nd->flags & LOOKUP_FOLLOW)) ||
+ (flags & WALK_NOFOLLOW)) {
/* not a symlink or should not follow */
- path_to_nameidata(path, nd);
+ path_to_nameidata(&path, nd);
nd->inode = inode;
nd->seq = seq;
- return 0;
+ return NULL;
}
/* make sure that d_is_symlink above matches inode */
if (nd->flags & LOOKUP_RCU) {
- if (read_seqcount_retry(&path->dentry->d_seq, seq))
- return -ECHILD;
+ if (read_seqcount_retry(&path.dentry->d_seq, seq))
+ return ERR_PTR(-ECHILD);
}
- return pick_link(nd, path, inode, seq);
+ return pick_link(nd, &path, inode, seq, flags);
}
-static int walk_component(struct nameidata *nd, int flags)
+static const char *walk_component(struct nameidata *nd, int flags)
{
- struct path path;
+ struct dentry *dentry;
struct inode *inode;
unsigned seq;
int err;
* parent relationships.
*/
if (unlikely(nd->last_type != LAST_NORM)) {
- err = handle_dots(nd, nd->last_type);
if (!(flags & WALK_MORE) && nd->depth)
put_link(nd);
- return err;
+ err = handle_dots(nd, nd->last_type);
+ return ERR_PTR(err);
}
- err = lookup_fast(nd, &path, &inode, &seq);
- if (unlikely(err <= 0)) {
- if (err < 0)
- return err;
- path.dentry = lookup_slow(&nd->last, nd->path.dentry,
- nd->flags);
- if (IS_ERR(path.dentry))
- return PTR_ERR(path.dentry);
-
- path.mnt = nd->path.mnt;
- err = follow_managed(&path, nd);
- if (unlikely(err < 0))
- return err;
-
- seq = 0; /* we are already out of RCU mode */
- inode = d_backing_inode(path.dentry);
+ dentry = lookup_fast(nd, &inode, &seq);
+ if (IS_ERR(dentry))
+ return ERR_CAST(dentry);
+ if (unlikely(!dentry)) {
+ dentry = lookup_slow(&nd->last, nd->path.dentry, nd->flags);
+ if (IS_ERR(dentry))
+ return ERR_CAST(dentry);
}
-
- return step_into(nd, &path, flags, inode, seq);
+ if (!(flags & WALK_MORE) && nd->depth)
+ put_link(nd);
+ return step_into(nd, flags, dentry, inode, seq);
}
/*
*/
static int link_path_walk(const char *name, struct nameidata *nd)
{
+ int depth = 0; // depth <= nd->depth
int err;
+ nd->last_type = LAST_ROOT;
+ nd->flags |= LOOKUP_PARENT;
if (IS_ERR(name))
return PTR_ERR(name);
while (*name=='/')
/* At this point we know we have a real path component. */
for(;;) {
+ const char *link;
u64 hash_len;
int type;
} while (unlikely(*name == '/'));
if (unlikely(!*name)) {
OK:
- /* pathname body, done */
- if (!nd->depth)
- return 0;
- name = nd->stack[nd->depth - 1].name;
- /* trailing symlink, done */
- if (!name)
+ /* pathname or trailing symlink, done */
+ if (!depth) {
+ nd->flags &= ~LOOKUP_PARENT;
return 0;
+ }
/* last component of nested symlink */
- err = walk_component(nd, WALK_FOLLOW);
+ name = nd->stack[--depth].name;
+ link = walk_component(nd, 0);
} else {
/* not the last component */
- err = walk_component(nd, WALK_FOLLOW | WALK_MORE);
+ link = walk_component(nd, WALK_MORE);
}
- if (err < 0)
- return err;
-
- if (err) {
- const char *s = get_link(nd);
-
- if (IS_ERR(s))
- return PTR_ERR(s);
- err = 0;
- if (unlikely(!s)) {
- /* jumped */
- put_link(nd);
- } else {
- nd->stack[nd->depth - 1].name = name;
- name = s;
- continue;
- }
+ if (unlikely(link)) {
+ if (IS_ERR(link))
+ return PTR_ERR(link);
+ /* a symlink to follow */
+ nd->stack[depth++].name = name;
+ name = link;
+ continue;
}
if (unlikely(!d_can_lookup(nd->path.dentry))) {
if (nd->flags & LOOKUP_RCU) {
if (flags & LOOKUP_RCU)
rcu_read_lock();
- nd->last_type = LAST_ROOT; /* if there are only slashes... */
- nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
+ nd->flags = flags | LOOKUP_JUMPED;
nd->depth = 0;
nd->m_seq = __read_seqcount_begin(&mount_lock.seqcount);
return s;
}
-static const char *trailing_symlink(struct nameidata *nd)
-{
- const char *s;
- int error = may_follow_link(nd);
- if (unlikely(error))
- return ERR_PTR(error);
- nd->flags |= LOOKUP_PARENT;
- nd->stack[0].name = NULL;
- s = get_link(nd);
- return s ? s : "";
-}
-
-static inline int lookup_last(struct nameidata *nd)
+static inline const char *lookup_last(struct nameidata *nd)
{
if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len])
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
- nd->flags &= ~LOOKUP_PARENT;
- return walk_component(nd, 0);
+ return walk_component(nd, WALK_TRAILING);
}
static int handle_lookup_down(struct nameidata *nd)
{
- struct path path = nd->path;
- struct inode *inode = nd->inode;
- unsigned seq = nd->seq;
- int err;
-
- if (nd->flags & LOOKUP_RCU) {
- /*
- * don't bother with unlazy_walk on failure - we are
- * at the very beginning of walk, so we lose nothing
- * if we simply redo everything in non-RCU mode
- */
- if (unlikely(!__follow_mount_rcu(nd, &path, &inode, &seq)))
- return -ECHILD;
- } else {
- dget(path.dentry);
- err = follow_managed(&path, nd);
- if (unlikely(err < 0))
- return err;
- inode = d_backing_inode(path.dentry);
- seq = 0;
- }
- path_to_nameidata(&path, nd);
- nd->inode = inode;
- nd->seq = seq;
- return 0;
+ if (!(nd->flags & LOOKUP_RCU))
+ dget(nd->path.dentry);
+ return PTR_ERR(step_into(nd, WALK_NOFOLLOW,
+ nd->path.dentry, nd->inode, nd->seq));
}
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
s = ERR_PTR(err);
}
- while (!(err = link_path_walk(s, nd))
- && ((err = lookup_last(nd)) > 0)) {
- s = trailing_symlink(nd);
- }
+ while (!(err = link_path_walk(s, nd)) &&
+ (s = lookup_last(nd)) != NULL)
+ ;
if (!err)
err = complete_walk(nd);
if (!err && nd->flags & LOOKUP_DIRECTORY)
if (!d_can_lookup(nd->path.dentry))
err = -ENOTDIR;
+ if (!err && unlikely(nd->flags & LOOKUP_MOUNTPOINT)) {
+ err = handle_lookup_down(nd);
+ nd->flags &= ~LOOKUP_JUMPED; // no d_weak_revalidate(), please...
+ }
if (!err) {
*path = nd->path;
nd->path.mnt = NULL;
retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path);
if (likely(!retval))
- audit_inode(name, path->dentry, 0);
+ audit_inode(name, path->dentry,
+ flags & LOOKUP_MOUNTPOINT ? AUDIT_INODE_NOEVAL : 0);
restore_nameidata();
putname(name);
return retval;
}
EXPORT_SYMBOL(user_path_at_empty);
-/**
- * path_mountpoint - look up a path to be umounted
- * @nd: 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(struct nameidata *nd, unsigned flags, struct path *path)
-{
- const char *s = path_init(nd, flags);
- int err;
-
- while (!(err = link_path_walk(s, nd)) &&
- (err = lookup_last(nd)) > 0) {
- s = trailing_symlink(nd);
- }
- if (!err && (nd->flags & LOOKUP_RCU))
- err = unlazy_walk(nd);
- if (!err)
- err = handle_lookup_down(nd);
- if (!err) {
- *path = nd->path;
- nd->path.mnt = NULL;
- nd->path.dentry = NULL;
- }
- terminate_walk(nd);
- return err;
-}
-
-static int
-filename_mountpoint(int dfd, struct filename *name, struct path *path,
- unsigned int flags)
-{
- struct nameidata nd;
- int error;
- if (IS_ERR(name))
- return PTR_ERR(name);
- set_nameidata(&nd, dfd, name);
- error = path_mountpoint(&nd, flags | LOOKUP_RCU, path);
- if (unlikely(error == -ECHILD))
- error = path_mountpoint(&nd, flags, path);
- if (unlikely(error == -ESTALE))
- error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
- if (likely(!error))
- audit_inode(name, path->dentry, AUDIT_INODE_NOEVAL);
- restore_nameidata();
- putname(name);
- return error;
-}
-
-/**
- * user_path_mountpoint_at - lookup a path from userland in order to umount it
- * @dfd: directory file descriptor
- * @name: pathname from userland
- * @flags: lookup flags
- * @path: pointer to container to hold result
- *
- * A umount is a special case for path walking. We're not actually interested
- * in the inode in this situation, and ESTALE errors can be a problem. We
- * simply want track down the dentry and vfsmount attached at the mountpoint
- * and avoid revalidating the last component.
- *
- * Returns 0 and populates "path" on success.
- */
-int
-user_path_mountpoint_at(int dfd, const char __user *name, unsigned int flags,
- struct path *path)
-{
- return filename_mountpoint(dfd, getname(name), path, flags);
-}
-
-int
-kern_path_mountpoint(int dfd, const char *name, struct path *path,
- unsigned int flags)
-{
- return filename_mountpoint(dfd, getname_kernel(name), path, flags);
-}
-EXPORT_SYMBOL(kern_path_mountpoint);
-
int __check_sticky(struct inode *dir, struct inode *inode)
{
kuid_t fsuid = current_fsuid();
*
* Returns an error code otherwise.
*/
-static int atomic_open(struct nameidata *nd, struct dentry *dentry,
- struct path *path, struct file *file,
- const struct open_flags *op,
- int open_flag, umode_t mode)
+static struct dentry *atomic_open(struct nameidata *nd, struct dentry *dentry,
+ struct file *file,
+ const struct open_flags *op,
+ int open_flag, umode_t mode)
{
struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
struct inode *dir = nd->path.dentry->d_inode;
}
if (file->f_mode & FMODE_CREATED)
fsnotify_create(dir, dentry);
- if (unlikely(d_is_negative(dentry))) {
+ if (unlikely(d_is_negative(dentry)))
error = -ENOENT;
- } else {
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 0;
- }
}
}
- dput(dentry);
- return error;
+ if (error) {
+ dput(dentry);
+ dentry = ERR_PTR(error);
+ }
+ return dentry;
}
/*
*
* An error code is returned on failure.
*/
-static int lookup_open(struct nameidata *nd, struct path *path,
- struct file *file,
- const struct open_flags *op,
- bool got_write)
+static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
+ const struct open_flags *op,
+ bool got_write)
{
struct dentry *dir = nd->path.dentry;
struct inode *dir_inode = dir->d_inode;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
if (unlikely(IS_DEADDIR(dir_inode)))
- return -ENOENT;
+ return ERR_PTR(-ENOENT);
file->f_mode &= ~FMODE_CREATED;
dentry = d_lookup(dir, &nd->last);
if (!dentry) {
dentry = d_alloc_parallel(dir, &nd->last, &wq);
if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ return dentry;
}
if (d_in_lookup(dentry))
break;
}
if (dentry->d_inode) {
/* Cached positive dentry: will open in f_op->open */
- goto out_no_open;
+ return dentry;
}
/*
}
if (dir_inode->i_op->atomic_open) {
- error = atomic_open(nd, dentry, path, file, op, open_flag,
- mode);
- if (unlikely(error == -ENOENT) && create_error)
- error = create_error;
- return error;
+ dentry = atomic_open(nd, dentry, file, op, open_flag, mode);
+ if (unlikely(create_error) && dentry == ERR_PTR(-ENOENT))
+ dentry = ERR_PTR(create_error);
+ return dentry;
}
no_open:
error = create_error;
goto out_dput;
}
-out_no_open:
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 0;
+ return dentry;
out_dput:
dput(dentry);
- return error;
+ return ERR_PTR(error);
}
/*
* Handle the last step of open()
*/
-static int do_last(struct nameidata *nd,
+static const char *do_last(struct nameidata *nd,
struct file *file, const struct open_flags *op)
{
struct dentry *dir = nd->path.dentry;
int acc_mode = op->acc_mode;
unsigned seq;
struct inode *inode;
- struct path path;
+ struct dentry *dentry;
+ const char *res;
int error;
- nd->flags &= ~LOOKUP_PARENT;
nd->flags |= op->intent;
if (nd->last_type != LAST_NORM) {
+ if (nd->depth)
+ put_link(nd);
error = handle_dots(nd, nd->last_type);
if (unlikely(error))
- return error;
+ return ERR_PTR(error);
goto finish_open;
}
if (nd->last.name[nd->last.len])
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
/* we _can_ be in RCU mode here */
- error = lookup_fast(nd, &path, &inode, &seq);
- if (likely(error > 0))
+ dentry = lookup_fast(nd, &inode, &seq);
+ if (IS_ERR(dentry))
+ return ERR_CAST(dentry);
+ if (likely(dentry))
goto finish_lookup;
- if (error < 0)
- return error;
-
BUG_ON(nd->inode != dir->d_inode);
BUG_ON(nd->flags & LOOKUP_RCU);
} else {
*/
error = complete_walk(nd);
if (error)
- return error;
+ return ERR_PTR(error);
audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
/* trailing slashes? */
if (unlikely(nd->last.name[nd->last.len]))
- return -EISDIR;
+ return ERR_PTR(-EISDIR);
}
if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
inode_lock(dir->d_inode);
else
inode_lock_shared(dir->d_inode);
- error = lookup_open(nd, &path, file, op, got_write);
+ dentry = lookup_open(nd, file, op, got_write);
if (open_flag & O_CREAT)
inode_unlock(dir->d_inode);
else
inode_unlock_shared(dir->d_inode);
- if (error)
+ if (IS_ERR(dentry)) {
+ error = PTR_ERR(dentry);
goto out;
+ }
if (file->f_mode & FMODE_OPENED) {
if ((file->f_mode & FMODE_CREATED) ||
will_truncate = false;
audit_inode(nd->name, file->f_path.dentry, 0);
+ dput(dentry);
goto opened;
}
open_flag &= ~O_TRUNC;
will_truncate = false;
acc_mode = 0;
- path_to_nameidata(&path, nd);
+ dput(nd->path.dentry);
+ nd->path.dentry = dentry;
goto finish_open_created;
}
got_write = false;
}
- error = follow_managed(&path, nd);
- if (unlikely(error < 0))
- return error;
-
- /*
- * create/update audit record if it already exists.
- */
- audit_inode(nd->name, path.dentry, 0);
+finish_lookup:
+ if (nd->depth)
+ put_link(nd);
+ res = step_into(nd, WALK_TRAILING, dentry, inode, seq);
+ if (unlikely(res)) {
+ nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
+ return res;
+ }
if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) {
- path_to_nameidata(&path, nd);
- return -EEXIST;
+ audit_inode(nd->name, nd->path.dentry, 0);
+ return ERR_PTR(-EEXIST);
}
-
- seq = 0; /* out of RCU mode, so the value doesn't matter */
- inode = d_backing_inode(path.dentry);
-finish_lookup:
- error = step_into(nd, &path, 0, inode, seq);
- if (unlikely(error))
- return error;
finish_open:
/* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */
error = complete_walk(nd);
if (error)
- return error;
+ return ERR_PTR(error);
audit_inode(nd->name, nd->path.dentry, 0);
if (open_flag & O_CREAT) {
error = -EISDIR;
}
if (got_write)
mnt_drop_write(nd->path.mnt);
- return error;
+ return ERR_PTR(error);
}
struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
} else {
const char *s = path_init(nd, flags);
while (!(error = link_path_walk(s, nd)) &&
- (error = do_last(nd, file, op)) > 0) {
- nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
- s = trailing_symlink(nd);
- }
+ (s = do_last(nd, file, op)) != NULL)
+ ;
terminate_walk(nd);
}
if (likely(!error)) {
projects / linux-2.6-microblaze.git / blobdiff