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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 09:47:30 -0700 |
| commit | 44d86dbf9af1f5d328057eb1137265231da17540 (patch) | |
| tree | b1f65f852aa6b64e59bd190c7978945b8f5434bb /fs/nfs | |
| parent | 412cfeec2f4851f266b20a12b3a81dcef94cb979 (diff) | |
| download | lwn-44d86dbf9af1f5d328057eb1137265231da17540.tar.gz lwn-44d86dbf9af1f5d328057eb1137265231da17540.zip | |
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>
Diffstat (limited to 'fs/nfs')
| -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 5fc2162afb67..46cfed63d229 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1531,9 +1531,9 @@ 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); nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); break; |