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| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-02-15 18:03:23 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-02-20 18:33:12 +0100 |
| commit | eacd9aa8cedeb412842c7b339adbaa0477fdd5ad (patch) | |
| tree | 12212663d52b32a50f9b5745d3c390496cbc499f /fs/namei.c | |
| parent | fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED (diff) | |
| download | linux-eacd9aa8cedeb412842c7b339adbaa0477fdd5ad.tar.xz linux-eacd9aa8cedeb412842c7b339adbaa0477fdd5ad.zip | |
fix handling of nd->depth on LOOKUP_CACHED failures in try_to_unlazy*
After switching to non-RCU mode, we want nd->depth to match the number
of entries in nd->stack[] that need eventual path_put().
legitimize_links() takes care of that on failures; unfortunately,
failure exits added for LOOKUP_CACHED do not.
We could add the logics for that into those failure exits, both in
try_to_unlazy() and in try_to_unlazy_next(), but since both checks
are immediately followed by legitimize_links() and there's no calls
of legitimize_links() other than those two... It's easier to
move the check (and required handling of nd->depth on failure) into
legitimize_links() itself.
[caught by Jens: ... and since we are zeroing ->depth here, we need
to do drop_links() first]
Fixes: 6c6ec2b0a3e0 "fs: add support for LOOKUP_CACHED"
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/namei.c b/fs/namei.c index 4cae88733a5c..de74ad2bc6e2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -630,6 +630,11 @@ static inline bool legitimize_path(struct nameidata *nd, static bool legitimize_links(struct nameidata *nd) { int i; + if (unlikely(nd->flags & LOOKUP_CACHED)) { + drop_links(nd); + nd->depth = 0; + return false; + } for (i = 0; i < nd->depth; i++) { struct saved *last = nd->stack + i; if (unlikely(!legitimize_path(nd, &last->link, last->seq))) { @@ -686,8 +691,6 @@ static bool try_to_unlazy(struct nameidata *nd) BUG_ON(!(nd->flags & LOOKUP_RCU)); nd->flags &= ~LOOKUP_RCU; - if (nd->flags & LOOKUP_CACHED) - goto out1; if (unlikely(!legitimize_links(nd))) goto out1; if (unlikely(!legitimize_path(nd, &nd->path, nd->seq))) @@ -724,8 +727,6 @@ static bool try_to_unlazy_next(struct nameidata *nd, struct dentry *dentry, unsi BUG_ON(!(nd->flags & LOOKUP_RCU)); nd->flags &= ~LOOKUP_RCU; - if (nd->flags & LOOKUP_CACHED) - goto out2; if (unlikely(!legitimize_links(nd))) goto out2; if (unlikely(!legitimize_mnt(nd->path.mnt, nd->m_seq))) |