On Fri, 2011-11-04 at 07:00 -0400, Jeff Layton wrote:
> commit d953126 changed how nfs_atomic_lookup handles an -EISDIR return
> from an OPEN call. Prior to that patch, that caused the client to fall
> back to doing a normal lookup. When that patch went in, the code began
> returning that error to userspace. The d_revalidate codepath however
> never had the corresponding change, so it was still possible to end up
> with a NULL ctx->state pointer after that.
>
> That patch caused a regression. When we attempt to open a directory that
> does not have a cached dentry, that open now errors out with EISDIR. If
> you attempt the same open with a cached dentry, it will succeed.
>
> Fix this by reverting the change in nfs_atomic_lookup and allowing
> attempts to open directories to fall back to a normal lookup
>
> Also, add a NFSv4-specific f_ops->open routine that just returns
> -ENOTDIR. This should never be called if things are working properly,
> but if it ever is, then the dprintk may help in debugging.
>
> Cc: stable@xxxxxxxxxx
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/nfs/dir.c | 2 +-
> fs/nfs/file.c | 31 +++++++++++++++++++++++++++++++
> fs/nfs/inode.c | 5 ++++-
> include/linux/nfs_fs.h | 1 +
> 4 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index b238d95..ac28990 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -1468,12 +1468,12 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry
> res = NULL;
> goto out;
> /* This turned out not to be a regular file */
> + case -EISDIR:
> case -ENOTDIR:
> goto no_open;
> case -ELOOP:
> if (!(nd->intent.open.flags & O_NOFOLLOW))
> goto no_open;
> - /* case -EISDIR: */
> /* case -EINVAL: */
> default:
> res = ERR_CAST(inode);
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 28b8c3f..9a5cab5 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -41,6 +41,7 @@
> #define NFSDBG_FACILITY NFSDBG_FILE
>
> static int nfs_file_open(struct inode *, struct file *);
> +static int nfs4_file_open(struct inode *, struct file *);
> static int nfs_file_release(struct inode *, struct file *);
> static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
> static int nfs_file_mmap(struct file *, struct vm_area_struct *);
> @@ -63,6 +64,25 @@ static int nfs_setlease(struct file *file, long arg, struct file_lock **fl);
>
> static const struct vm_operations_struct nfs_file_vm_ops;
>
> +const struct file_operations nfs4_file_operations = {
> + .llseek = nfs_file_llseek,
> + .read = do_sync_read,
> + .write = do_sync_write,
> + .aio_read = nfs_file_read,
> + .aio_write = nfs_file_write,
> + .mmap = nfs_file_mmap,
> + .open = nfs4_file_open,
> + .flush = nfs_file_flush,
> + .release = nfs_file_release,
> + .fsync = nfs_file_fsync,
> + .lock = nfs_lock,
> + .flock = nfs_flock,
> + .splice_read = nfs_file_splice_read,
> + .splice_write = nfs_file_splice_write,
> + .check_flags = nfs_check_flags,
> + .setlease = nfs_setlease,
> +};
Don't the additions to this file need to be enclosed in '#ifdef
CONFIG_NFS_V4' sections?
Also, why not move the declaration of nfs4_file_operations to the end of
the file so that we can skip the forward declaration of nfs4_file_open?
> +
> const struct file_operations nfs_file_operations = {
> .llseek = nfs_file_llseek,
> .read = do_sync_read,
> @@ -135,6 +155,17 @@ nfs_file_open(struct inode *inode, struct file *filp)
> }
>
> static int
> +nfs4_file_open(struct inode *inode, struct file *filp)
> +{
> + /*
> + * NFSv4 opens are handled in d_lookup and d_revalidate. If we get to
> + * this point, then something is very wrong
> + */
> + dprintk("NFS: %s called! inode=%p filp=%p\n", __func__, inode, filp);
> + return -ENOTDIR;
> +}
> +
> +static int
> nfs_file_release(struct inode *inode, struct file *filp)
> {
> struct dentry *dentry = filp->f_path.dentry;
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index 4dc6d07..4c61717 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -291,7 +291,10 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
> */
> inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
> if (S_ISREG(inode->i_mode)) {
> - inode->i_fop = &nfs_file_operations;
> + if (NFS_SB(sb)->nfs_client->rpc_ops->version == 4)
> + inode->i_fop = &nfs4_file_operations;
Please add a 'struct file_operations' entry to struct nfs_rpc_ops so
that we can avoid the check for version == 4.
> + else
> + inode->i_fop = &nfs_file_operations;
> inode->i_data.a_ops = &nfs_file_aops;
> inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
> } else if (S_ISDIR(inode->i_mode)) {
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index 60a137b..2af9c67 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -409,6 +409,7 @@ extern const struct inode_operations nfs_file_inode_operations;
> extern const struct inode_operations nfs3_file_inode_operations;
> #endif /* CONFIG_NFS_V3 */
> extern const struct file_operations nfs_file_operations;
> +extern const struct file_operations nfs4_file_operations;
> extern const struct address_space_operations nfs_file_aops;
> extern const struct address_space_operations nfs_dir_aops;
>
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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