diff options
| author | Nick Piggin <npiggin@kernel.dk> | 2010-08-18 04:37:30 +1000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-08-18 08:35:45 -0400 |
| commit | 2e2e88ea8c3bd9e1bd6e42faf047a4ac3fbb3b2f (patch) | |
| tree | 398f6de92d9e41419297354a26e25e0db8a693f6 /fs/namei.c | |
| parent | 3a48ee8a4ad26c3a538b6fc11a86a8f80c3dce18 (diff) | |
| download | lwn-2e2e88ea8c3bd9e1bd6e42faf047a4ac3fbb3b2f.tar.gz lwn-2e2e88ea8c3bd9e1bd6e42faf047a4ac3fbb3b2f.zip | |
fs: fix do_lookup false negative
fs: fix do_lookup false negative
In do_lookup, if we initially find no dentry, we take the directory i_mutex and
re-check the lookup. If we find a dentry there, then we revalidate it if
needed. However if that revalidate asks for the dentry to be invalidated, we
return -ENOENT from do_lookup. What should happen instead is an attempt to
allocate and lookup a new dentry.
This is probably not noticed because it is rare. It is only reached if a
concurrent create races in first (in which case, the dentry probably won't be
invalidated anyway), or if the racy __d_lookup has failed due to a
false-negative (which is very rare).
Fix this by removing code and have it use the normal reval path.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/fs/namei.c b/fs/namei.c index 17ea76bf2fbe..c2742b7dec59 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -709,6 +709,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, dentry = __d_lookup(nd->path.dentry, name); if (!dentry) goto need_lookup; +found: if (dentry->d_op && dentry->d_op->d_revalidate) goto need_revalidate; done: @@ -766,14 +767,7 @@ out_unlock: * we waited on the semaphore. Need to revalidate. */ mutex_unlock(&dir->i_mutex); - if (dentry->d_op && dentry->d_op->d_revalidate) { - dentry = do_revalidate(dentry, nd); - if (!dentry) - dentry = ERR_PTR(-ENOENT); - } - if (IS_ERR(dentry)) - goto fail; - goto done; + goto found; need_revalidate: dentry = do_revalidate(dentry, nd); |