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

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.

Cc: stable@kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index b238d95ac48c7b926ff1e02eae157ea09fa58a68..ac289909814768a626ad817dbf40627805e7899e 100644 (file)
--- 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 0a1f8312b4dcf0fe9272310f1ab6d00178cdd2a8..6d93e0754b5edacb718ec7e6227f9dddd37b11cd 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -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 */

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index c07a55aec83867ee1489ff29134862bc891dfa82..50a15fa8cf985e41e21b786f4f6d9d9ed96cf37e 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -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)) {

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 85f1690ca08c110bcd1c1754e564f23619295a1a..d4bc9ed917484106dbed777942e0db096be08236 100644 (file)
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -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,

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b60fddf606f7d23e6f01305420446d74102001a7..069cb8094d43c7b7f048c67dec0db041f84a4917 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -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,

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index ac40b8535d7e0e7493f13063afdbe57169837c9e..f48125da198a2d5a50bc0861805212a129427920 100644 (file)
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -710,6 +710,7 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
        .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,

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index ab2c6343361ae3e82f242df7880f292c189e442d..92ecf5585facf20511cd865db281d33ea828bdad 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -410,6 +410,9 @@ 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;
+#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;
 

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index c74595ba70947926d2b1a99f4157ca7f485dbd13..2a7c533be5dd8aa2f584fde1faad94c558130d75 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1192,6 +1192,7 @@ 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 *);