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nothing in do_follow_link() is going to see RCU 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-02-15 00:38:26 -05:00
parent 795abaf1e4
commit 844a391799
1 changed files with 7 additions and 8 deletions
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15
fs/namei.c
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@ -668,9 +668,6 @@ force_reval_path(struct path *path, struct nameidata *nd)
return 0; return 0;
if (!status) { if (!status) {
/* Don't d_invalidate in rcu-walk mode */
if (nameidata_drop_rcu(nd))
return -ECHILD;
d_invalidate(dentry); d_invalidate(dentry);
status = -ESTALE; status = -ESTALE;
} }
@ -777,6 +774,8 @@ __do_follow_link(const struct path *link, struct nameidata *nd, void **p)
int error; int error;
struct dentry *dentry = link->dentry; struct dentry *dentry = link->dentry;
BUG_ON(nd->flags & LOOKUP_RCU);
touch_atime(link->mnt, dentry); touch_atime(link->mnt, dentry);
nd_set_link(nd, NULL); nd_set_link(nd, NULL);
@ -811,6 +810,11 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd)
{ {
void *cookie; void *cookie;
int err = -ELOOP; int err = -ELOOP;
/* We drop rcu-walk here */
if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
return -ECHILD;
if (current->link_count >= MAX_NESTED_LINKS) if (current->link_count >= MAX_NESTED_LINKS)
goto loop; goto loop;
if (current->total_link_count >= 40) if (current->total_link_count >= 40)
@ -1419,9 +1423,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
goto out_dput; goto out_dput;
if (inode->i_op->follow_link) { if (inode->i_op->follow_link) {
/* We commonly drop rcu-walk here */
if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
return -ECHILD;
BUG_ON(inode != next.dentry->d_inode); BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd); err = do_follow_link(&next, nd);
if (err) if (err)
@ -1467,8 +1468,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
break; break;
if (inode && unlikely(inode->i_op->follow_link) && if (inode && unlikely(inode->i_op->follow_link) &&
(lookup_flags & LOOKUP_FOLLOW)) { (lookup_flags & LOOKUP_FOLLOW)) {
if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
return -ECHILD;
BUG_ON(inode != next.dentry->d_inode); BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd); err = do_follow_link(&next, nd);
if (err) if (err)