[25/53] nfs: when attempting to open a directory, fall back on normal lookup (try #5)

Greg KH
2011-11-23T00:41:13Z

From: Jeff Layton <jlayton@redhat.com>

commit 1788ea6e3b2a58cf4fb00206e362d9caff8d86a7 upstream.

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.

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

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/nfs/dir.c | 2 +-
fs/nfs/file.c | 32 ++++++++++++++++++++++++++++++++
fs/nfs/inode.c | 2 +-
fs/nfs/nfs3proc.c | 1 +
fs/nfs/nfs4proc.c | 1 +
fs/nfs/proc.c | 1 +
include/linux/nfs_fs.h | 3 +++
include/linux/nfs_xdr.h | 1 +
8 files changed, 41 insertions(+), 2 deletions(-)

--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1458,12 +1458,12 @@ static struct dentry *nfs_atomic_lookup(
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);
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -887,3 +887,35 @@ static int nfs_setlease(struct file *fil
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 */
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -291,7 +291,7 @@ nfs_fhget(struct super_block *sb, struct
*/
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)) {
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -853,6 +853,7 @@ const struct nfs_rpc_ops nfs_v3_clientop
.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,
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6008,6 +6008,7 @@ const struct nfs_rpc_ops nfs_v4_clientop
.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,
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -710,6 +710,7 @@ const struct nfs_rpc_ops nfs_v2_clientop
.dentry_ops = &nfs_dentry_operations,
.dir_inode_ops = &nfs_dir_inode_operations,
.file_inode_ops = &nfs_file_inode_operations,
+ .file_ops = &nfs_file_operations,
.getroot = nfs_proc_get_root,
.getattr = nfs_proc_getattr,
.setattr = nfs_proc_setattr,
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -410,6 +410,9 @@ extern const struct inode_operations nfs
extern const struct inode_operations nfs3_file_inode_operations;
#endif /* CONFIG_NFS_V3 */
extern const struct file_operations nfs_file_operations;
+#ifdef CONFIG_NFS_V4
+extern const struct file_operations nfs4_file_operations;
+#endif /* CONFIG_NFS_V4 */
extern const struct address_space_operations nfs_file_aops;
extern const struct address_space_operations nfs_dir_aops;

--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1149,6 +1149,7 @@ struct nfs_rpc_ops {
const struct dentry_operations *dentry_ops;
const struct inode_operations *dir_inode_ops;
const struct inode_operations *file_inode_ops;
+ const struct file_operations *file_ops;

int (*getroot) (struct nfs_server *, struct nfs_fh *,
struct nfs_fsinfo *);