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author | Al Viro <viro@ZenIV.linux.org.uk> | 2016-06-20 13:14:36 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-07-27 09:55:49 -0700 |
commit | b149020bae2c1b0e3644df1d7f6e5d72cffcf9c2 (patch) | |
tree | 0786b2bb8b55357fdc517add45d9f5f15a110643 | |
parent | d2329b25771434dee8dbd349814be6d794ce08ab (diff) | |
download | linux-stable-b149020bae2c1b0e3644df1d7f6e5d72cffcf9c2.tar.gz |
make nfs_atomic_open() call d_drop() on all ->open_context() errors.
commit d20cb71dbf3487f24549ede1a8e2d67579b4632e upstream.
In "NFSv4: Move dentry instantiation into the NFSv4-specific atomic open code"
unconditional d_drop() after the ->open_context() had been removed. It had
been correct for success cases (there ->open_context() itself had been doing
dcache manipulations), but not for error ones. Only one of those (ENOENT)
got a compensatory d_drop() added in that commit, but in fact it should've
been done for all errors. As it is, the case of O_CREAT non-exclusive open
on a hashed negative dentry racing with e.g. symlink creation from another
client ended up with ->open_context() getting an error and proceeding to
call nfs_lookup(). On a hashed dentry, which would've instantly triggered
BUG_ON() in d_materialise_unique() (or, these days, its equivalent in
d_splice_alias()).
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | fs/nfs/dir.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 4a48fe4b84b6..589418d44310 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1459,9 +1459,9 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry, err = PTR_ERR(inode); trace_nfs_atomic_open_exit(dir, ctx, open_flags, err); put_nfs_open_context(ctx); + d_drop(dentry); switch (err) { case -ENOENT: - d_drop(dentry); d_add(dentry, NULL); break; case -EISDIR: |