forked from luck/tmp_suning_uos_patched
split do_revalidate() into RCU and non-RCU cases
fixing oopsen in lookup_one_len() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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parent
24643087e7
commit
f5e1c1c1af
47
fs/namei.c
47
fs/namei.c
@ -592,12 +592,10 @@ static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
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return status;
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}
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static inline struct dentry *
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static struct dentry *
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do_revalidate(struct dentry *dentry, struct nameidata *nd)
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{
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int status;
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status = d_revalidate(dentry, nd);
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int status = d_revalidate(dentry, nd);
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if (unlikely(status <= 0)) {
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/*
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* The dentry failed validation.
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@ -606,24 +604,39 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
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* to return a fail status.
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*/
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if (status < 0) {
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/* If we're in rcu-walk, we don't have a ref */
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if (!(nd->flags & LOOKUP_RCU))
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dput(dentry);
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dput(dentry);
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dentry = ERR_PTR(status);
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} else {
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/* Don't d_invalidate in rcu-walk mode */
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if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
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return ERR_PTR(-ECHILD);
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if (!d_invalidate(dentry)) {
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dput(dentry);
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dentry = NULL;
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}
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} else if (!d_invalidate(dentry)) {
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dput(dentry);
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dentry = NULL;
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}
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}
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return dentry;
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}
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static inline struct dentry *
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do_revalidate_rcu(struct dentry *dentry, struct nameidata *nd)
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{
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int status = dentry->d_op->d_revalidate(dentry, nd);
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if (likely(status > 0))
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return dentry;
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if (status == -ECHILD) {
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if (nameidata_dentry_drop_rcu(nd, dentry))
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return ERR_PTR(-ECHILD);
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return do_revalidate(dentry, nd);
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}
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if (status < 0)
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return ERR_PTR(status);
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/* Don't d_invalidate in rcu-walk mode */
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if (nameidata_dentry_drop_rcu(nd, dentry))
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return ERR_PTR(-ECHILD);
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if (!d_invalidate(dentry)) {
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dput(dentry);
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dentry = NULL;
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}
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return dentry;
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}
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static inline int need_reval_dot(struct dentry *dentry)
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{
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if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
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@ -1260,7 +1273,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
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nd->seq = seq;
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if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
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dentry = do_revalidate(dentry, nd);
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dentry = do_revalidate_rcu(dentry, nd);
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if (!dentry)
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goto need_lookup;
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if (IS_ERR(dentry))
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