Commit 1788ea6e authored by Jeff Layton's avatar Jeff Layton Committed by Trond Myklebust
Browse files

nfs: when attempting to open a directory, fall back on normal lookup (try #5) 



commit d953126a 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.

To facilitate this, a new file_operations field is also added to the
nfs_rpc_ops struct.

Cc: stable@kernel.org
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 15831714

fs/nfs/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

fs/nfs/file.c

+32 −0
Original line number Diff line number Diff line
@@ -886,3 +886,35 @@ static int nfs_setlease(struct file *file, long arg, struct file_lock **fl) 
			file->f_path.dentry->d_name.name, arg);

	return -EINVAL;

}



#ifdef CONFIG_NFS_V4

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;

}



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,

};

#endif /* CONFIG_NFS_V4 */

fs/nfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -291,7 +291,7 @@ 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;

			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;

			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)) {

fs/nfs/nfs3proc.c

+1 −0
Original line number Diff line number Diff line
@@ -853,6 +853,7 @@ const struct nfs_rpc_ops nfs_v3_clientops = { 
	.dentry_ops	= &nfs_dentry_operations,

	.dir_inode_ops	= &nfs3_dir_inode_operations,

	.file_inode_ops	= &nfs3_file_inode_operations,

	.file_ops	= &nfs_file_operations,

	.getroot	= nfs3_proc_get_root,

	.getattr	= nfs3_proc_getattr,

	.setattr	= nfs3_proc_setattr,

fs/nfs/nfs4proc.c

+1 −0
Original line number Diff line number Diff line
@@ -6253,6 +6253,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = { 
	.dentry_ops	= &nfs4_dentry_operations,

	.dir_inode_ops	= &nfs4_dir_inode_operations,

	.file_inode_ops	= &nfs4_file_inode_operations,

	.file_ops	= &nfs4_file_operations,

	.getroot	= nfs4_proc_get_root,

	.getattr	= nfs4_proc_getattr,

	.setattr	= nfs4_proc_setattr,

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