diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-04-27 01:11:55 -0400 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-05-17 16:31:08 -0400 |
| commit | d6c198421db212898a96a3e34d7e526abca67a3a (patch) | |
| tree | 64ca4a60aba662b296db9dd208b720b374b89067 /fs | |
| parent | 65c2cfa5e503d8fdca05cd6b75b78e61b4415ae4 (diff) | |
atomic_open(): fix the handling of create_error
[ Upstream commit 10c64cea04d3c75c306b3f990586ffb343b63287 ]
* if we have a hashed negative dentry and either CREAT|EXCL on
r/o filesystem, or CREAT|TRUNC on r/o filesystem, or CREAT|EXCL
with failing may_o_create(), we should fail with EROFS or the
error may_o_create() has returned, but not ENOENT. Which is what
the current code ends up returning.
* if we have CREAT|TRUNC hitting a regular file on a read-only
filesystem, we can't fail with EROFS here. At the very least,
not until we'd done follow_managed() - we might have a writable
file (or a device, for that matter) bound on top of that one.
Moreover, the code downstream will see that O_TRUNC and attempt
to grab the write access (*after* following possible mount), so
if we really should fail with EROFS, it will happen. No need
to do that inside atomic_open().
The real logics is much simpler than what the current code is
trying to do - if we decided to go for simple lookup, ended
up with a negative dentry *and* had create_error set, fail with
create_error. No matter whether we'd got that negative dentry
from lookup_real() or had found it in dcache.
Cc: stable@vger.kernel.org # v3.6+
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namei.c | 20 |
1 files changed, 4 insertions, 16 deletions
diff --git a/fs/namei.c b/fs/namei.c index 2a8ba683a888..e1976450a1e2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2797,22 +2797,10 @@ no_open: dentry = lookup_real(dir, dentry, nd->flags); if (IS_ERR(dentry)) return PTR_ERR(dentry); - - if (create_error) { - int open_flag = op->open_flag; - - error = create_error; - if ((open_flag & O_EXCL)) { - if (!dentry->d_inode) - goto out; - } else if (!dentry->d_inode) { - goto out; - } else if ((open_flag & O_TRUNC) && - S_ISREG(dentry->d_inode->i_mode)) { - goto out; - } - /* will fail later, go on to get the right error */ - } + } + if (create_error && !dentry->d_inode) { + error = create_error; + goto out; } looked_up: path->dentry = dentry; |