[PATCH 00/34] vfs: atomic open v3

[PATCH 00/34] vfs: atomic open v3

[Miklos Szeredi]

This series allows clean implementation of atomic lookup+(create)+open
operations that previously were done via ->lookup and ->create using open
intents.

Changes from the last version:

 - fixed some bugs
 - pulled the EOPENSTALE patches towards the head of the queue
 - split up some patches for easier reviewability

git tree is here:

  git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git atomic-open.v3

Thanks,
Miklos
---


Miklos Szeredi (34):
      vfs: split do_lookup()
      vfs: do_last(): make exit RCU safe
      vfs: do_last(): inline walk_component()
      vfs: do_last(): use inode variable
      vfs: make follow_link check RCU safe
      vfs: do_last(): make ENOENT exit RCU safe
      vfs: do_last(): check LOOKUP_DIRECTORY
      vfs: do_last(): only return EISDIR for O_CREAT
      vfs: do_last(): add audit_inode before open
      vfs: do_last() common post lookup
      vfs: split __dentry_open()
      vfs: do_dentry_open(): don't put filp
      vfs: nameidata_to_filp(): inline __dentry_open()
      vfs: nameidata_to_filp(): don't throw away file on error
      vfs: retry last component if opening stale dentry
      nfs: don't open in ->d_revalidate
      vfs: do_last(): inline lookup_slow()
      vfs: do_last(): separate O_CREAT specific code
      vfs: do_last(): common slow lookup
      vfs: add lookup_open()
      vfs: lookup_open(): expand lookup_hash()
      vfs: add i_op->atomic_open()
      nfs: implement i_op->atomic_open()
      nfs: clean up ->create in nfs_rpc_ops
      nfs: don't use nd->intent.open.flags
      nfs: don't use intents for checking atomic open
      fuse: implement i_op->atomic_create()
      cifs: implement i_op->atomic_open() and i_op->atomic_create()
      ceph: remove unused arg from ceph_lookup_open()
      ceph: implement i_op->atomic_open() and i_op->atomic_create()
      9p: implement i_op->atomic_create()
      vfs: remove open intents from nameidata
      vfs: do_last(): clean up error handling
      vfs: move O_DIRECT check to common code

---
 fs/9p/vfs_inode.c       |  169 +++++++++------
 fs/9p/vfs_inode_dotl.c  |   52 +++--
 fs/ceph/dir.c           |   68 ++++---
 fs/ceph/file.c          |   22 +-
 fs/ceph/super.h         |    6 +-
 fs/cifs/cifsfs.c        |    1 +
 fs/cifs/cifsfs.h        |    3 +
 fs/cifs/dir.c           |  437 +++++++++++++++++++++-----------------
 fs/fuse/dir.c           |   97 ++++++---
 fs/internal.h           |    9 +-
 fs/namei.c              |  553 +++++++++++++++++++++++++++++++++++------------
 fs/nfs/dir.c            |  298 +++++++++-----------------
 fs/nfs/file.c           |   77 +++++++-
 fs/nfs/nfs3proc.c       |    2 +-
 fs/nfs/nfs4proc.c       |   37 +---
 fs/nfs/proc.c           |    2 +-
 fs/open.c               |  123 +++++------
 include/linux/errno.h   |    1 +
 include/linux/fs.h      |    7 +
 include/linux/namei.h   |   11 -
 include/linux/nfs_xdr.h |    2 +-
 21 files changed, 1190 insertions(+), 787 deletions(-)

[PATCH 01/34] vfs: split do_lookup()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Split do_lookup() into two functions:

  lookup_fast() - does cached lookup without i_mutex
  lookup_slow() - does lookup with i_mutex

Both follow managed dentries.

The new functions are needed by atomic_open.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   59 +++++++++++++++++++++++++++++++++++++++++++++--------------
 1 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 1898198..338410a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1138,8 +1138,8 @@ static struct dentry *__lookup_hash(struct qstr *name,
  *  small and for now I'd prefer to have fast path as straight as possible.
  *  It _is_ time-critical.
  */
-static int do_lookup(struct nameidata *nd, struct qstr *name,
-			struct path *path, struct inode **inode)
+static int lookup_fast(struct nameidata *nd, struct qstr *name,
+		       struct path *path, struct inode **inode)
 {
 	struct vfsmount *mnt = nd->path.mnt;
 	struct dentry *dentry, *parent = nd->path.dentry;
@@ -1208,7 +1208,7 @@ unlazy:
 			goto need_lookup;
 		}
 	}
-done:
+
 	path->mnt = mnt;
 	path->dentry = dentry;
 	err = follow_managed(path, nd->flags);
@@ -1222,6 +1222,17 @@ done:
 	return 0;
 
 need_lookup:
+	return 1;
+}
+
+/* Fast lookup failed, do it the slow way */
+static int lookup_slow(struct nameidata *nd, struct qstr *name,
+		       struct path *path)
+{
+	struct dentry *dentry, *parent;
+	int err;
+
+	parent = nd->path.dentry;
 	BUG_ON(nd->inode != parent->d_inode);
 
 	mutex_lock(&parent->d_inode->i_mutex);
@@ -1229,7 +1240,16 @@ need_lookup:
 	mutex_unlock(&parent->d_inode->i_mutex);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
-	goto done;
+	path->mnt = nd->path.mnt;
+	path->dentry = dentry;
+	err = follow_managed(path, nd->flags);
+	if (unlikely(err < 0)) {
+		path_put_conditional(path, nd);
+		return err;
+	}
+	if (err)
+		nd->flags |= LOOKUP_JUMPED;
+	return 0;
 }
 
 static inline int may_lookup(struct nameidata *nd)
@@ -1301,21 +1321,26 @@ static inline int walk_component(struct nameidata *nd, struct path *path,
 	 */
 	if (unlikely(type != LAST_NORM))
 		return handle_dots(nd, type);
-	err = do_lookup(nd, name, path, &inode);
+	err = lookup_fast(nd, name, path, &inode);
 	if (unlikely(err)) {
-		terminate_walk(nd);
-		return err;
-	}
-	if (!inode) {
-		path_to_nameidata(path, nd);
-		terminate_walk(nd);
-		return -ENOENT;
+		if (err < 0)
+			goto out_err;
+
+		err = lookup_slow(nd, name, path);
+		if (err < 0)
+			goto out_err;
+
+		inode = path->dentry->d_inode;
 	}
+	err = -ENOENT;
+	if (!inode)
+		goto out_path_put;
+
 	if (should_follow_link(inode, follow)) {
 		if (nd->flags & LOOKUP_RCU) {
 			if (unlikely(unlazy_walk(nd, path->dentry))) {
-				terminate_walk(nd);
-				return -ECHILD;
+				err = -ECHILD;
+				goto out_err;
 			}
 		}
 		BUG_ON(inode != path->dentry->d_inode);
@@ -1324,6 +1349,12 @@ static inline int walk_component(struct nameidata *nd, struct path *path,
 	path_to_nameidata(path, nd);
 	nd->inode = inode;
 	return 0;
+
+out_path_put:
+	path_to_nameidata(path, nd);
+out_err:
+	terminate_walk(nd);
+	return err;
 }
 
 /*
-- 
1.7.7

[PATCH 02/34] vfs: do_last(): make exit RCU safe

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Allow returning from do_last() with LOOKUP_RCU still set on the "out:" and
"exit:" labels.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 338410a..dc4003e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2414,7 +2414,7 @@ common:
 out:
 	if (want_write)
 		mnt_drop_write(nd->path.mnt);
-	path_put(&nd->path);
+	terminate_walk(nd);
 	return filp;
 
 exit_mutex_unlock:
-- 
1.7.7

[PATCH 03/34] vfs: do_last(): inline walk_component()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Copy walk_component() into do_lookup().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   35 ++++++++++++++++++++++++++++++-----
 1 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index dc4003e..0ca5e40 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2231,6 +2231,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	int want_write = 0;
 	int acc_mode = op->acc_mode;
 	struct file *filp;
+	struct inode *inode;
 	int error;
 
 	nd->flags &= ~LOOKUP_PARENT;
@@ -2268,12 +2269,36 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 		if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW))
 			symlink_ok = 1;
 		/* we _can_ be in RCU mode here */
-		error = walk_component(nd, path, &nd->last, LAST_NORM,
-					!symlink_ok);
-		if (error < 0)
-			return ERR_PTR(error);
-		if (error) /* symlink */
+		error = lookup_fast(nd, &nd->last, path, &inode);
+		if (unlikely(error)) {
+			if (error < 0)
+				goto exit;
+
+			error = lookup_slow(nd, &nd->last, path);
+			if (error < 0)
+				goto exit;
+
+			inode = path->dentry->d_inode;
+		}
+		error = -ENOENT;
+		if (!inode) {
+			path_to_nameidata(path, nd);
+			goto exit;
+		}
+
+		if (should_follow_link(inode, !symlink_ok)) {
+			if (nd->flags & LOOKUP_RCU) {
+				if (unlikely(unlazy_walk(nd, path->dentry))) {
+					error = -ECHILD;
+					goto exit;
+				}
+			}
+			BUG_ON(inode != path->dentry->d_inode);
 			return NULL;
+		}
+		path_to_nameidata(path, nd);
+		nd->inode = inode;
+
 		/* sayonara */
 		error = complete_walk(nd);
 		if (error)
-- 
1.7.7

[PATCH 04/34] vfs: do_last(): use inode variable

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Use helper variable instead of path->dentry->d_inode before complete_walk().
This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 0ca5e40..58d1f62 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2389,15 +2389,16 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	if (error)
 		nd->flags |= LOOKUP_JUMPED;
 
+	inode = path->dentry->d_inode;
 	error = -ENOENT;
-	if (!path->dentry->d_inode)
+	if (!inode)
 		goto exit_dput;
 
-	if (path->dentry->d_inode->i_op->follow_link)
+	if (inode->i_op->follow_link)
 		return NULL;
 
 	path_to_nameidata(path, nd);
-	nd->inode = path->dentry->d_inode;
+	nd->inode = inode;
 	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
 	error = complete_walk(nd);
 	if (error)
-- 
1.7.7

[PATCH 05/34] vfs: make follow_link check RCU safe

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 58d1f62..a94b0d4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2232,6 +2232,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	int acc_mode = op->acc_mode;
 	struct file *filp;
 	struct inode *inode;
+	int symlink_ok = 0;
 	int error;
 
 	nd->flags &= ~LOOKUP_PARENT;
@@ -2263,7 +2264,6 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	}
 
 	if (!(open_flag & O_CREAT)) {
-		int symlink_ok = 0;
 		if (nd->last.name[nd->last.len])
 			nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
 		if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW))
@@ -2394,8 +2394,16 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	if (!inode)
 		goto exit_dput;
 
-	if (inode->i_op->follow_link)
+	if (should_follow_link(inode, !symlink_ok)) {
+		if (nd->flags & LOOKUP_RCU) {
+			if (unlikely(unlazy_walk(nd, path->dentry))) {
+				error = -ECHILD;
+				goto exit;
+			}
+		}
+		BUG_ON(inode != path->dentry->d_inode);
 		return NULL;
+	}
 
 	path_to_nameidata(path, nd);
 	nd->inode = inode;
-- 
1.7.7

[PATCH 06/34] vfs: do_last(): make ENOENT exit RCU safe

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index a94b0d4..709e992 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2391,8 +2391,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
 	inode = path->dentry->d_inode;
 	error = -ENOENT;
-	if (!inode)
-		goto exit_dput;
+	if (!inode) {
+		path_to_nameidata(path, nd);
+		goto exit;
+	}
 
 	if (should_follow_link(inode, !symlink_ok)) {
 		if (nd->flags & LOOKUP_RCU) {
-- 
1.7.7

[PATCH 07/34] vfs: do_last(): check LOOKUP_DIRECTORY

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Check for ENOTDIR before finishing open.  This allows this code to be shared
between O_CREAT and plain opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 709e992..06ff96f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2416,6 +2416,9 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	error = -EISDIR;
 	if (S_ISDIR(nd->inode->i_mode))
 		goto exit;
+	error = -ENOTDIR;
+	if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
+		goto exit;
 ok:
 	if (!S_ISREG(nd->inode->i_mode))
 		will_truncate = 0;
-- 
1.7.7

[PATCH 08/34] vfs: do_last(): only return EISDIR for O_CREAT

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

This allows this code to be shared between O_CREAT and plain opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 06ff96f..a405260 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2414,7 +2414,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	if (error)
 		return ERR_PTR(error);
 	error = -EISDIR;
-	if (S_ISDIR(nd->inode->i_mode))
+	if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode))
 		goto exit;
 	error = -ENOTDIR;
 	if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
-- 
1.7.7

[PATCH 09/34] vfs: do_last(): add audit_inode before open

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

This allows this code to be shared between O_CREAT and plain opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index a405260..69adb62 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2419,6 +2419,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	error = -ENOTDIR;
 	if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
 		goto exit;
+	audit_inode(pathname, nd->path.dentry);
 ok:
 	if (!S_ISREG(nd->inode->i_mode))
 		will_truncate = 0;
-- 
1.7.7

[PATCH 10/34] vfs: do_last() common post lookup

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Now the post lookup code can be shared between O_CREAT and plain opens since
they are essentially the same.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   33 ++-------------------------------
 1 files changed, 2 insertions(+), 31 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 69adb62..9e4ec13 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2280,37 +2280,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
 			inode = path->dentry->d_inode;
 		}
-		error = -ENOENT;
-		if (!inode) {
-			path_to_nameidata(path, nd);
-			goto exit;
-		}
-
-		if (should_follow_link(inode, !symlink_ok)) {
-			if (nd->flags & LOOKUP_RCU) {
-				if (unlikely(unlazy_walk(nd, path->dentry))) {
-					error = -ECHILD;
-					goto exit;
-				}
-			}
-			BUG_ON(inode != path->dentry->d_inode);
-			return NULL;
-		}
-		path_to_nameidata(path, nd);
-		nd->inode = inode;
-
-		/* sayonara */
-		error = complete_walk(nd);
-		if (error)
-			return ERR_PTR(error);
-
-		error = -ENOTDIR;
-		if (nd->flags & LOOKUP_DIRECTORY) {
-			if (!nd->inode->i_op->lookup)
-				goto exit;
-		}
-		audit_inode(pathname, nd->path.dentry);
-		goto ok;
+		goto finish_lookup;
 	}
 
 	/* create side of things */
@@ -2390,6 +2360,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 		nd->flags |= LOOKUP_JUMPED;
 
 	inode = path->dentry->d_inode;
+finish_lookup:
 	error = -ENOENT;
 	if (!inode) {
 		path_to_nameidata(path, nd);
-- 
1.7.7

[PATCH 11/34] vfs: split __dentry_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Split __dentry_open() into two functions:

  do_dentry_open() - does most of the actual work, doesn't put file on failure
  open_check_o_direct() - after a successful open, checks direct_IO method

This will allow i_op->atomic_open to do just the file initialization and leave
the direct_IO checking to the VFS.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/internal.h |    1 +
 fs/open.c     |   47 +++++++++++++++++++++++++++++++++--------------
 2 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 9962c59..4d69fdd 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -100,6 +100,7 @@ extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
 
 extern long do_handle_open(int mountdirfd,
 			   struct file_handle __user *ufh, int open_flag);
+extern int open_check_o_direct(struct file *f);
 
 /*
  * inode.c
diff --git a/fs/open.c b/fs/open.c
index 5720854..971b474 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -644,10 +644,23 @@ static inline int __get_file_write_access(struct inode *inode,
 	return error;
 }
 
-static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
-					struct file *f,
-					int (*open)(struct inode *, struct file *),
-					const struct cred *cred)
+int open_check_o_direct(struct file *f)
+{
+	/* NB: we're sure to have correct a_ops only after f_op->open */
+	if (f->f_flags & O_DIRECT) {
+		if (!f->f_mapping->a_ops ||
+		    ((!f->f_mapping->a_ops->direct_IO) &&
+		    (!f->f_mapping->a_ops->get_xip_mem))) {
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+				   struct file *f,
+				   int (*open)(struct inode *, struct file *),
+				   const struct cred *cred)
 {
 	static const struct file_operations empty_fops = {};
 	struct inode *inode;
@@ -703,16 +716,6 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 
 	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
 
-	/* NB: we're sure to have correct a_ops only after f_op->open */
-	if (f->f_flags & O_DIRECT) {
-		if (!f->f_mapping->a_ops ||
-		    ((!f->f_mapping->a_ops->direct_IO) &&
-		    (!f->f_mapping->a_ops->get_xip_mem))) {
-			fput(f);
-			f = ERR_PTR(-EINVAL);
-		}
-	}
-
 	return f;
 
 cleanup_all:
@@ -740,6 +743,22 @@ cleanup_file:
 	return ERR_PTR(error);
 }
 
+static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+				struct file *f,
+				int (*open)(struct inode *, struct file *),
+				const struct cred *cred)
+{
+	struct file *res = do_dentry_open(dentry, mnt, f, open, cred);
+	if (!IS_ERR(res)) {
+		int error = open_check_o_direct(f);
+		if (error) {
+			fput(res);
+			res = ERR_PTR(error);
+		}
+	}
+	return res;
+}
+
 /**
  * lookup_instantiate_filp - instantiates the open intent filp
  * @nd: pointer to nameidata
-- 
1.7.7

[PATCH 12/34] vfs: do_dentry_open(): don't put filp

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Move put_filp() out to __dentry_open(), the only caller now.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/open.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index 971b474..e1448cd 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -737,7 +737,6 @@ cleanup_all:
 	f->f_path.dentry = NULL;
 	f->f_path.mnt = NULL;
 cleanup_file:
-	put_filp(f);
 	dput(dentry);
 	mntput(mnt);
 	return ERR_PTR(error);
@@ -755,6 +754,8 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 			fput(res);
 			res = ERR_PTR(error);
 		}
+	} else {
+		put_filp(f);
 	}
 	return res;
 }
-- 
1.7.7

[PATCH 13/34] vfs: nameidata_to_filp(): inline __dentry_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Copy __dentry_open() into nameidata_to_filp().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/open.c |   20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index e1448cd..161c15f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -818,9 +818,25 @@ struct file *nameidata_to_filp(struct nameidata *nd)
 
 	/* Has the filesystem initialised the file for us? */
 	if (filp->f_path.dentry == NULL) {
+		struct file *res;
+
 		path_get(&nd->path);
-		filp = __dentry_open(nd->path.dentry, nd->path.mnt, filp,
-				     NULL, cred);
+		res = do_dentry_open(nd->path.dentry, nd->path.mnt,
+				     filp, NULL, cred);
+		if (!IS_ERR(res)) {
+			int error;
+
+			BUG_ON(res != filp);
+
+			error = open_check_o_direct(filp);
+			if (error) {
+				fput(filp);
+				filp = ERR_PTR(error);
+			}
+		} else {
+			put_filp(filp);
+			filp = res;
+		}
 	}
 	return filp;
 }
-- 
1.7.7

[PATCH 14/34] vfs: nameidata_to_filp(): don't throw away file on error

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

If open fails, don't put the file.  This allows it to be reused if open needs to
be retried.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/open.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index 161c15f..0510e58 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -814,10 +814,11 @@ struct file *nameidata_to_filp(struct nameidata *nd)
 
 	/* Pick up the filp from the open intent */
 	filp = nd->intent.open.file;
-	nd->intent.open.file = NULL;
 
 	/* Has the filesystem initialised the file for us? */
-	if (filp->f_path.dentry == NULL) {
+	if (filp->f_path.dentry != NULL) {
+		nd->intent.open.file = NULL;
+	} else {
 		struct file *res;
 
 		path_get(&nd->path);
@@ -826,6 +827,7 @@ struct file *nameidata_to_filp(struct nameidata *nd)
 		if (!IS_ERR(res)) {
 			int error;
 
+			nd->intent.open.file = NULL;
 			BUG_ON(res != filp);
 
 			error = open_check_o_direct(filp);
@@ -834,7 +836,7 @@ struct file *nameidata_to_filp(struct nameidata *nd)
 				filp = ERR_PTR(error);
 			}
 		} else {
-			put_filp(filp);
+			/* Allow nd->intent.open.file to be recycled */
 			filp = res;
 		}
 	}
-- 
1.7.7

[PATCH 15/34] vfs: retry last component if opening stale dentry

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

NFS optimizes away d_revalidates for last component of open.  This means that
open itself can find the dentry stale.

This patch allows the filesystem to return EOPENSTALE and the VFS will retry the
lookup on just the last component if possible.

If the lookup was done using RCU mode, including the last component, then this
is not possible since the parent dentry is lost.  In this case fall back to
non-RCU lookup.  Currently this is not used since NFS will always leave RCU
mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c            |   37 +++++++++++++++++++++++++++++++++++--
 include/linux/errno.h |    1 +
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 9e4ec13..c8a8b28 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2233,6 +2233,8 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	struct file *filp;
 	struct inode *inode;
 	int symlink_ok = 0;
+	struct path save_parent = { .dentry = NULL, .mnt = NULL };
+	bool retried = false;
 	int error;
 
 	nd->flags &= ~LOOKUP_PARENT;
@@ -2298,6 +2300,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	if (nd->last.name[nd->last.len])
 		goto exit;
 
+retry_lookup:
 	mutex_lock(&dir->d_inode->i_mutex);
 
 	dentry = lookup_hash(nd);
@@ -2378,12 +2381,21 @@ finish_lookup:
 		return NULL;
 	}
 
-	path_to_nameidata(path, nd);
+	if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) {
+		path_to_nameidata(path, nd);
+	} else {
+		save_parent.dentry = nd->path.dentry;
+		save_parent.mnt = mntget(path->mnt);
+		nd->path.dentry = path->dentry;
+
+	}
 	nd->inode = inode;
 	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
 	error = complete_walk(nd);
-	if (error)
+	if (error) {
+		path_put(&save_parent);
 		return ERR_PTR(error);
+	}
 	error = -EISDIR;
 	if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode))
 		goto exit;
@@ -2406,6 +2418,20 @@ common:
 	if (error)
 		goto exit;
 	filp = nameidata_to_filp(nd);
+	if (filp == ERR_PTR(-EOPENSTALE) && save_parent.dentry && !retried) {
+		BUG_ON(save_parent.dentry != dir);
+		path_put(&nd->path);
+		nd->path = save_parent;
+		nd->inode = dir->d_inode;
+		save_parent.mnt = NULL;
+		save_parent.dentry = NULL;
+		if (want_write) {
+			mnt_drop_write(nd->path.mnt);
+			want_write = 0;
+		}
+		retried = true;
+		goto retry_lookup;
+	}
 	if (!IS_ERR(filp)) {
 		error = ima_file_check(filp, op->acc_mode);
 		if (error) {
@@ -2425,6 +2451,7 @@ common:
 out:
 	if (want_write)
 		mnt_drop_write(nd->path.mnt);
+	path_put(&save_parent);
 	terminate_walk(nd);
 	return filp;
 
@@ -2488,6 +2515,12 @@ out:
 	if (base)
 		fput(base);
 	release_open_intent(nd);
+	if (filp == ERR_PTR(-EOPENSTALE)) {
+		if (flags & LOOKUP_RCU)
+			filp = ERR_PTR(-ECHILD);
+		else
+			filp = ERR_PTR(-ESTALE);
+	}
 	return filp;
 
 out_filp:
diff --git a/include/linux/errno.h b/include/linux/errno.h
index 2d09bfa..e0de516 100644
--- a/include/linux/errno.h
+++ b/include/linux/errno.h
@@ -17,6 +17,7 @@
 #define ENOIOCTLCMD	515	/* No ioctl command */
 #define ERESTART_RESTARTBLOCK 516 /* restart by calling sys_restart_syscall */
 #define EPROBE_DEFER	517	/* Driver requests probe retry */
+#define EOPENSTALE	518	/* open found a stale dentry */
 
 /* Defined for the NFSv3 protocol */
 #define EBADHANDLE	521	/* Illegal NFS file handle */
-- 
1.7.7

[PATCH 16/34] nfs: don't open in ->d_revalidate

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

NFSv4 can't do reliable opens in d_revalidate, since it cannot know whether a
mount needs to be followed or not.  It does check d_mountpoint() on the dentry,
which can result in a weird error if the VFS found that the mount does not in
fact need to be followed, e.g.:

  # mount --bind /mnt/nfs /mnt/nfs-clone
  # echo something > /mnt/nfs/tmp/bar
  # echo x > /tmp/file
  # mount --bind /tmp/file /mnt/nfs-clone/tmp/bar
  # cat  /mnt/nfs/tmp/bar
  cat: /mnt/nfs/tmp/bar: Not a directory

Which should, by any sane filesystem, result in "something" being printed.

So instead do the open in f_op->open() and in the unlikely case that the cached
dentry turned out to be invalid, drop the dentry and return ESTALE to let the
VFS retry.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 fs/nfs/dir.c  |   56 +++-------------------------------------
 fs/nfs/file.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 78 insertions(+), 55 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 4aaf031..10ce72e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1328,10 +1328,10 @@ out:
 }
 
 #ifdef CONFIG_NFS_V4
-static int nfs_open_revalidate(struct dentry *, struct nameidata *);
+static int nfs4_lookup_revalidate(struct dentry *, struct nameidata *);
 
 const struct dentry_operations nfs4_dentry_operations = {
-	.d_revalidate	= nfs_open_revalidate,
+	.d_revalidate	= nfs4_lookup_revalidate,
 	.d_delete	= nfs_dentry_delete,
 	.d_iput		= nfs_dentry_iput,
 	.d_automount	= nfs_d_automount,
@@ -1493,13 +1493,11 @@ no_open:
 	return nfs_lookup(dir, dentry, nd);
 }
 
-static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
+static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct dentry *parent = NULL;
 	struct inode *inode;
 	struct inode *dir;
-	struct nfs_open_context *ctx;
-	struct iattr attr;
 	int openflags, ret = 0;
 
 	if (nd->flags & LOOKUP_RCU)
@@ -1528,57 +1526,13 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
 	/* We cannot do exclusive creation on a positive dentry */
 	if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
 		goto no_open_dput;
-	/* We can't create new files here */
-	openflags &= ~(O_CREAT|O_EXCL);
-
-	ctx = create_nfs_open_context(dentry, openflags);
-	ret = PTR_ERR(ctx);
-	if (IS_ERR(ctx))
-		goto out;
 
-	attr.ia_valid = 0;
-	if (openflags & O_TRUNC) {
-		attr.ia_valid |= ATTR_SIZE;
-		attr.ia_size = 0;
-		nfs_wb_all(inode);
-	}
-
-	/*
-	 * Note: we're not holding inode->i_mutex and so may be racing with
-	 * operations that change the directory. We therefore save the
-	 * change attribute *before* we do the RPC call.
-	 */
-	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr);
-	if (IS_ERR(inode)) {
-		ret = PTR_ERR(inode);
-		switch (ret) {
-		case -EPERM:
-		case -EACCES:
-		case -EDQUOT:
-		case -ENOSPC:
-		case -EROFS:
-			goto out_put_ctx;
-		default:
-			goto out_drop;
-		}
-	}
-	iput(inode);
-	if (inode != dentry->d_inode)
-		goto out_drop;
+	/* Let f_op->open() actually open (and revalidate) the file */
+	ret = 1;
 
-	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-	ret = nfs_intent_set_file(nd, ctx);
-	if (ret >= 0)
-		ret = 1;
 out:
 	dput(parent);
 	return ret;
-out_drop:
-	d_drop(dentry);
-	ret = 0;
-out_put_ctx:
-	put_nfs_open_context(ctx);
-	goto out;
 
 no_open_dput:
 	dput(parent);
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index aa9b709..92268bf 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -871,12 +871,81 @@ const struct file_operations nfs_file_operations = {
 static int
 nfs4_file_open(struct inode *inode, struct file *filp)
 {
+	struct nfs_open_context *ctx;
+	struct dentry *dentry = filp->f_path.dentry;
+	struct dentry *parent = NULL;
+	struct inode *dir;
+	unsigned openflags = filp->f_flags;
+	struct iattr attr;
+	int err;
+
+	BUG_ON(inode != dentry->d_inode);
 	/*
-	 * NFSv4 opens are handled in d_lookup and d_revalidate. If we get to
-	 * this point, then something is very wrong
+	 * If no cached dentry exists or if it's negative, NFSv4 handled the
+	 * opens in ->lookup() or ->create().
+	 *
+	 * We only get this far for a cached positive dentry.  We skipped
+	 * revalidation, so handle it here by dropping the dentry and returning
+	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 	 */
-	dprintk("NFS: %s called! inode=%p filp=%p\n", __func__, inode, filp);
-	return -ENOTDIR;
+
+	dprintk("NFS: open file(%s/%s)\n",
+		dentry->d_parent->d_name.name,
+		dentry->d_name.name);
+
+	if ((openflags & O_ACCMODE) == 3)
+		openflags--;
+
+	/* We can't create new files here */
+	openflags &= ~(O_CREAT|O_EXCL);
+
+	parent = dget_parent(dentry);
+	dir = parent->d_inode;
+
+	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
+	err = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	attr.ia_valid = 0;
+	if (openflags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+		nfs_wb_all(inode);
+	}
+
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		switch (err) {
+		case -EPERM:
+		case -EACCES:
+		case -EDQUOT:
+		case -ENOSPC:
+		case -EROFS:
+			goto out_put_ctx;
+		default:
+			goto out_drop;
+		}
+	}
+	iput(inode);
+	if (inode != dentry->d_inode)
+		goto out_drop;
+
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	nfs_file_set_open_context(filp, ctx);
+	err = 0;
+
+out_put_ctx:
+	put_nfs_open_context(ctx);
+out:
+	dput(parent);
+	return err;
+
+out_drop:
+	d_drop(dentry);
+	err = -EOPENSTALE;
+	goto out_put_ctx;
 }
 
 const struct file_operations nfs4_file_operations = {
-- 
1.7.7

Re: [PATCH 16/34] nfs: don't open in ->d_revalidate

[Christoph Hellwig]

On Thu, Apr 05, 2012 at 04:58:42PM +0200, Miklos Szeredi wrote:
> dentry turned out to be invalid, drop the dentry and return ESTALE to let the
> VFS retry.

This should read EOPENSTALE.

[PATCH 17/34] vfs: do_last(): inline lookup_slow()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Copy lookup_slow() into do_last().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index c8a8b28..47bff57 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2276,9 +2276,22 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 			if (error < 0)
 				goto exit;
 
-			error = lookup_slow(nd, &nd->last, path);
-			if (error < 0)
+			BUG_ON(nd->inode != dir->d_inode);
+
+			mutex_lock(&dir->d_inode->i_mutex);
+			dentry = __lookup_hash(&nd->last, dir, nd);
+			mutex_unlock(&dir->d_inode->i_mutex);
+			error = PTR_ERR(dentry);
+			if (IS_ERR(dentry))
 				goto exit;
+			path->mnt = nd->path.mnt;
+			path->dentry = dentry;
+			error = follow_managed(path, nd->flags);
+			if (unlikely(error < 0))
+				goto exit_dput;
+
+			if (error)
+				nd->flags |= LOOKUP_JUMPED;
 
 			inode = path->dentry->d_inode;
 		}
-- 
1.7.7

[PATCH 18/34] vfs: do_last(): separate O_CREAT specific code

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Check O_CREAT on the slow lookup paths where necessary.  This allows the rest to
be shared with plain open.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 47bff57..f89827a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2296,22 +2296,23 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 			inode = path->dentry->d_inode;
 		}
 		goto finish_lookup;
-	}
-
-	/* create side of things */
-	/*
-	 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been
-	 * cleared when we got to the last component we are about to look up
-	 */
-	error = complete_walk(nd);
-	if (error)
-		return ERR_PTR(error);
+	} else {
+		/* create side of things */
+		/*
+		 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED
+		 * has been cleared when we got to the last component we are
+		 * about to look up
+		 */
+		error = complete_walk(nd);
+		if (error)
+			return ERR_PTR(error);
 
-	audit_inode(pathname, dir);
-	error = -EISDIR;
-	/* trailing slashes? */
-	if (nd->last.name[nd->last.len])
-		goto exit;
+		audit_inode(pathname, dir);
+		error = -EISDIR;
+		/* trailing slashes? */
+		if (nd->last.name[nd->last.len])
+			goto exit;
+	}
 
 retry_lookup:
 	mutex_lock(&dir->d_inode->i_mutex);
@@ -2327,7 +2328,7 @@ retry_lookup:
 	path->mnt = nd->path.mnt;
 
 	/* Negative dentry, just create the file */
-	if (!dentry->d_inode) {
+	if (!dentry->d_inode && (open_flag & O_CREAT)) {
 		umode_t mode = op->mode;
 		if (!IS_POSIXACL(dir->d_inode))
 			mode &= ~current_umask();
-- 
1.7.7

[PATCH 19/34] vfs: do_last(): common slow lookup

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Make the slow lookup part of O_CREAT and non-O_CREAT opens common.

This allows atomic_open to be hooked into the slow lookup part.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   27 +++++----------------------
 1 files changed, 5 insertions(+), 22 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index f89827a..a7a9c2e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2272,30 +2272,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 			symlink_ok = 1;
 		/* we _can_ be in RCU mode here */
 		error = lookup_fast(nd, &nd->last, path, &inode);
-		if (unlikely(error)) {
-			if (error < 0)
-				goto exit;
-
-			BUG_ON(nd->inode != dir->d_inode);
-
-			mutex_lock(&dir->d_inode->i_mutex);
-			dentry = __lookup_hash(&nd->last, dir, nd);
-			mutex_unlock(&dir->d_inode->i_mutex);
-			error = PTR_ERR(dentry);
-			if (IS_ERR(dentry))
-				goto exit;
-			path->mnt = nd->path.mnt;
-			path->dentry = dentry;
-			error = follow_managed(path, nd->flags);
-			if (unlikely(error < 0))
-				goto exit_dput;
+		if (likely(!error))
+			goto finish_lookup;
 
-			if (error)
-				nd->flags |= LOOKUP_JUMPED;
+		if (error < 0)
+			goto exit;
 
-			inode = path->dentry->d_inode;
-		}
-		goto finish_lookup;
+		BUG_ON(nd->inode != dir->d_inode);
 	} else {
 		/* create side of things */
 		/*
-- 
1.7.7

[PATCH 20/34] vfs: add lookup_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Split out lookup + maybe create from do_last().  This is the part under i_mutex
protection.

The function is called lookup_open() and returns a filp even though the open
part is not used yet.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   99 +++++++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 61 insertions(+), 38 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index a7a9c2e..426b544 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2219,19 +2219,73 @@ static inline int open_to_namei_flags(int flag)
 }
 
 /*
+ * Lookup, maybe create and open the last component
+ *
+ * Must be called with i_mutex held on parent.
+ *
+ * Returns open file or NULL on success, error otherwise.  NULL means no open
+ * was performed, only lookup.
+ */
+static struct file *lookup_open(struct nameidata *nd, struct path *path,
+				const struct open_flags *op,
+				int *want_write, bool *created)
+{
+	struct dentry *dir = nd->path.dentry;
+	struct dentry *dentry;
+	int error;
+
+	*created = false;
+	dentry = lookup_hash(nd);
+	if (IS_ERR(dentry))
+		return ERR_CAST(dentry);
+
+	/* Negative dentry, just create the file */
+	if (!dentry->d_inode && (op->open_flag & O_CREAT)) {
+		umode_t mode = op->mode;
+		if (!IS_POSIXACL(dir->d_inode))
+			mode &= ~current_umask();
+		/*
+		 * This write is needed to ensure that a
+		 * rw->ro transition does not occur between
+		 * the time when the file is created and when
+		 * a permanent write count is taken through
+		 * the 'struct file' in nameidata_to_filp().
+		 */
+		error = mnt_want_write(nd->path.mnt);
+		if (error)
+			goto out_dput;
+		*want_write = 1;
+		*created = true;
+		error = security_path_mknod(&nd->path, dentry, mode, 0);
+		if (error)
+			goto out_dput;
+		error = vfs_create(dir->d_inode, dentry, mode, nd);
+		if (error)
+			goto out_dput;
+	}
+	path->dentry = dentry;
+	path->mnt = nd->path.mnt;
+	return NULL;
+
+out_dput:
+	dput(dentry);
+	return ERR_PTR(error);
+}
+
+/*
  * Handle the last step of open()
  */
 static struct file *do_last(struct nameidata *nd, struct path *path,
 			    const struct open_flags *op, const char *pathname)
 {
 	struct dentry *dir = nd->path.dentry;
-	struct dentry *dentry;
 	int open_flag = op->open_flag;
 	int will_truncate = open_flag & O_TRUNC;
 	int want_write = 0;
 	int acc_mode = op->acc_mode;
 	struct file *filp;
 	struct inode *inode;
+	bool created;
 	int symlink_ok = 0;
 	struct path save_parent = { .dentry = NULL, .mnt = NULL };
 	bool retried = false;
@@ -2299,53 +2353,24 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
 retry_lookup:
 	mutex_lock(&dir->d_inode->i_mutex);
+	filp = lookup_open(nd, path, op, &want_write, &created);
+	mutex_unlock(&dir->d_inode->i_mutex);
 
-	dentry = lookup_hash(nd);
-	error = PTR_ERR(dentry);
-	if (IS_ERR(dentry)) {
-		mutex_unlock(&dir->d_inode->i_mutex);
-		goto exit;
-	}
-
-	path->dentry = dentry;
-	path->mnt = nd->path.mnt;
+	if (IS_ERR(filp))
+		goto out;
 
-	/* Negative dentry, just create the file */
-	if (!dentry->d_inode && (open_flag & O_CREAT)) {
-		umode_t mode = op->mode;
-		if (!IS_POSIXACL(dir->d_inode))
-			mode &= ~current_umask();
-		/*
-		 * This write is needed to ensure that a
-		 * rw->ro transition does not occur between
-		 * the time when the file is created and when
-		 * a permanent write count is taken through
-		 * the 'struct file' in nameidata_to_filp().
-		 */
-		error = mnt_want_write(nd->path.mnt);
-		if (error)
-			goto exit_mutex_unlock;
-		want_write = 1;
+	if (created) {
 		/* Don't check for write permission, don't truncate */
 		open_flag &= ~O_TRUNC;
 		will_truncate = 0;
 		acc_mode = MAY_OPEN;
-		error = security_path_mknod(&nd->path, dentry, mode, 0);
-		if (error)
-			goto exit_mutex_unlock;
-		error = vfs_create(dir->d_inode, dentry, mode, nd);
-		if (error)
-			goto exit_mutex_unlock;
-		mutex_unlock(&dir->d_inode->i_mutex);
-		dput(nd->path.dentry);
-		nd->path.dentry = dentry;
+		path_to_nameidata(path, nd);
 		goto common;
 	}
 
 	/*
 	 * It already exists.
 	 */
-	mutex_unlock(&dir->d_inode->i_mutex);
 	audit_inode(pathname, path->dentry);
 
 	error = -EEXIST;
@@ -2452,8 +2477,6 @@ out:
 	terminate_walk(nd);
 	return filp;
 
-exit_mutex_unlock:
-	mutex_unlock(&dir->d_inode->i_mutex);
 exit_dput:
 	path_put_conditional(path, nd);
 exit:
-- 
1.7.7

[PATCH 21/34] vfs: lookup_open(): expand lookup_hash()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Copy __lookup_hash() into lookup_open().  The next patch will insert the atomic
open call just before the real lookup.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 426b544..4815607 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2231,14 +2231,24 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 				int *want_write, bool *created)
 {
 	struct dentry *dir = nd->path.dentry;
+	struct inode *dir_inode = dir->d_inode;
 	struct dentry *dentry;
 	int error;
+	bool need_lookup;
 
 	*created = false;
-	dentry = lookup_hash(nd);
+	dentry = lookup_dcache(&nd->last, dir, nd, &need_lookup);
 	if (IS_ERR(dentry))
 		return ERR_CAST(dentry);
 
+	if (need_lookup) {
+		BUG_ON(dentry->d_inode);
+
+		dentry = lookup_real(dir_inode, dentry, nd);
+		if (IS_ERR(dentry))
+			return ERR_CAST(dentry);
+	}
+
 	/* Negative dentry, just create the file */
 	if (!dentry->d_inode && (op->open_flag & O_CREAT)) {
 		umode_t mode = op->mode;
-- 
1.7.7

[PATCH 22/34] vfs: add i_op->atomic_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Add a new inode operation which is called on the last component of an open.
Using this the filesystem can look up, possibly create and open the file in one
atomic operation.  If it cannot perform this (e.g. the file type turned out to
be wrong) it may signal this by returning NULL instead of an open struct file
pointer.

i_op->atomic_open() is only called if the last component is negative or needs
lookup.  Handling cached positive dentries here doesn't add much value: these
can be opened using f_op->open().  If the cached file turns out to be invalid,
the open can be retried, this time using ->atomic_open() with a fresh dentry.

For now leave the old way of using open intents in lookup and revalidate in
place.  This will be removed once all the users are converted.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/internal.h      |    5 ++
 fs/namei.c         |  203 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/open.c          |   42 +++++++++++
 include/linux/fs.h |    7 ++
 4 files changed, 255 insertions(+), 2 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 4d69fdd..78c5c47 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -87,6 +87,11 @@ extern struct super_block *user_get_super(dev_t);
 struct nameidata;
 extern struct file *nameidata_to_filp(struct nameidata *);
 extern void release_open_intent(struct nameidata *);
+struct opendata {
+	struct dentry *dentry;
+	struct vfsmount *mnt;
+	struct file **filp;
+};
 struct open_flags {
 	int open_flag;
 	umode_t mode;
diff --git a/fs/namei.c b/fs/namei.c
index 4815607..4d505a4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2218,6 +2218,176 @@ static inline int open_to_namei_flags(int flag)
 	return flag;
 }
 
+static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
+{
+	int error = security_path_mknod(dir, dentry, mode, 0);
+	if (error)
+		return error;
+
+	error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC);
+	if (error)
+		return error;
+
+	return security_inode_create(dir->dentry->d_inode, dentry, mode);
+}
+
+static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
+				struct path *path, const struct open_flags *op,
+				int *want_write, bool need_lookup,
+				bool *created)
+{
+	struct inode *dir =  nd->path.dentry->d_inode;
+	unsigned open_flag = open_to_namei_flags(op->open_flag);
+	umode_t mode;
+	int error;
+	int acc_mode;
+	struct opendata od;
+	struct file *filp;
+	int create_error = 0;
+	struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
+
+	BUG_ON(dentry->d_inode);
+
+	/* Don't create child dentry for a dead directory. */
+	if (unlikely(IS_DEADDIR(dir))) {
+		filp = ERR_PTR(-ENOENT);
+		goto out;
+	}
+
+	mode = op->mode & S_IALLUGO;
+	if ((open_flag & O_CREAT) && !IS_POSIXACL(dir))
+		mode &= ~current_umask();
+
+	if (open_flag & O_EXCL) {
+		open_flag &= ~O_TRUNC;
+		*created = true;
+	}
+
+	/*
+	 * Checking write permission is tricky, bacuse we don't know if we are
+	 * going to actually need it: O_CREAT opens should work as long as the
+	 * file exists.  But checking existence breaks atomicity.  The trick is
+	 * to check access and if not granted clear O_CREAT from the flags.
+	 *
+	 * Another problem is returing the "right" error value (e.g. for an
+	 * O_EXCL open we want to return EEXIST not EROFS).
+	 */
+	if ((open_flag & (O_CREAT | O_TRUNC)) ||
+	    (open_flag & O_ACCMODE) != O_RDONLY) {
+		error = mnt_want_write(nd->path.mnt);
+		if (!error) {
+			*want_write = 1;
+		} else if (!(open_flag & O_CREAT)) {
+			/*
+			 * No O_CREATE -> atomicity not a requirement -> fall
+			 * back to lookup + open
+			 */
+			goto no_open;
+		} else if (open_flag & (O_EXCL | O_TRUNC)) {
+			/* Fall back and fail with the right error */
+			create_error = error;
+			goto no_open;
+		} else {
+			/* No side effects, safe to clear O_CREAT */
+			create_error = error;
+			open_flag &= ~O_CREAT;
+		}
+	}
+
+	if (open_flag & O_CREAT) {
+		error = may_o_create(&nd->path, dentry, op->mode);
+		if (error) {
+			create_error = error;
+			if (open_flag & O_EXCL)
+				goto no_open;
+			open_flag &= ~O_CREAT;
+		}
+	}
+
+	if (nd->flags & LOOKUP_DIRECTORY)
+		open_flag |= O_DIRECTORY;
+
+	od.dentry = DENTRY_NOT_SET;
+	od.mnt = nd->path.mnt;
+	od.filp = &nd->intent.open.file;
+	filp = dir->i_op->atomic_open(dir, dentry, &od, open_flag, mode,
+				      created);
+	if (IS_ERR(filp)) {
+		if (WARN_ON(od.dentry != DENTRY_NOT_SET))
+			dput(od.dentry);
+
+		if (create_error && PTR_ERR(filp) == -ENOENT)
+			filp = ERR_PTR(create_error);
+		goto out;
+	}
+
+	acc_mode = op->acc_mode;
+	if (*created) {
+		fsnotify_create(dir, dentry);
+		acc_mode = MAY_OPEN;
+	}
+
+	if (!filp) {
+		if (WARN_ON(od.dentry == DENTRY_NOT_SET)) {
+			filp = ERR_PTR(-EIO);
+			goto out;
+		}
+		if (od.dentry) {
+			dput(dentry);
+			dentry = od.dentry;
+		}
+		goto looked_up;
+	}
+
+	/*
+	 * We didn't have the inode before the open, so check open permission
+	 * here.
+	 */
+	error = may_open(&filp->f_path, acc_mode, open_flag);
+	if (error)
+		goto out_fput;
+
+	error = open_check_o_direct(filp);
+	if (error)
+		goto out_fput;
+
+out:
+	dput(dentry);
+	return filp;
+
+out_fput:
+	fput(filp);
+	filp = ERR_PTR(error);
+	goto out;
+
+no_open:
+	if (need_lookup) {
+		dentry = lookup_real(dir, dentry, nd);
+		if (IS_ERR(dentry))
+			return ERR_CAST(dentry);
+
+		if (create_error) {
+			int open_flag = op->open_flag;
+
+			filp = ERR_PTR(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 */
+		}
+	}
+looked_up:
+	path->dentry = dentry;
+	path->mnt = nd->path.mnt;
+	return NULL;
+}
+
 /*
  * Lookup, maybe create and open the last component
  *
@@ -2241,6 +2411,15 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 	if (IS_ERR(dentry))
 		return ERR_CAST(dentry);
 
+	/* Cached positive dentry: will open in f_op->open */
+	if (!need_lookup && dentry->d_inode)
+		goto out_no_open;
+
+	if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
+		return atomic_open(nd, dentry, path, op, want_write,
+				   need_lookup, created);
+	}
+
 	if (need_lookup) {
 		BUG_ON(dentry->d_inode);
 
@@ -2273,6 +2452,7 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 		if (error)
 			goto out_dput;
 	}
+out_no_open:
 	path->dentry = dentry;
 	path->mnt = nd->path.mnt;
 	return NULL;
@@ -2366,8 +2546,16 @@ retry_lookup:
 	filp = lookup_open(nd, path, op, &want_write, &created);
 	mutex_unlock(&dir->d_inode->i_mutex);
 
-	if (IS_ERR(filp))
-		goto out;
+	if (filp) {
+		if (IS_ERR(filp))
+			goto out;
+
+		if (created)
+			will_truncate = 0;
+
+		audit_inode(pathname, filp->f_path.dentry);
+		goto opened;
+	}
 
 	if (created) {
 		/* Don't check for write permission, don't truncate */
@@ -2383,6 +2571,16 @@ retry_lookup:
 	 */
 	audit_inode(pathname, path->dentry);
 
+	/*
+	 * If atomic_open() acquired write access it is dropped now due to
+	 * possible mount and symlink following (this might be optimized away if
+	 * necessary...)
+	 */
+	if (want_write) {
+		mnt_drop_write(nd->path.mnt);
+		want_write = 0;
+	}
+
 	error = -EEXIST;
 	if (open_flag & O_EXCL)
 		goto exit_dput;
@@ -2464,6 +2662,7 @@ common:
 		retried = true;
 		goto retry_lookup;
 	}
+opened:
 	if (!IS_ERR(filp)) {
 		error = ima_file_check(filp, op->acc_mode);
 		if (error) {
diff --git a/fs/open.c b/fs/open.c
index 0510e58..a973c2c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -801,6 +801,48 @@ out_err:
 EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
 
 /**
+ * finish_open - finish opening a file
+ * @od: opaque open data
+ * @dentry: pointer to dentry
+ * @open: open callback
+ *
+ * This can be used to finish opening a file passed to i_op->atomic_open().
+ *
+ * If the open callback is set to NULL, then the standard f_op->open()
+ * filesystem callback is substituted.
+ */
+struct file *finish_open(struct opendata *od, struct dentry *dentry,
+			 int (*open)(struct inode *, struct file *))
+{
+	struct file *res;
+
+	mntget(od->mnt);
+	dget(dentry);
+
+	res = do_dentry_open(dentry, od->mnt, *od->filp, open, current_cred());
+	if (!IS_ERR(res))
+		*od->filp = NULL;
+
+	return res;
+}
+EXPORT_SYMBOL(finish_open);
+
+/**
+ * finish_no_open - finish ->atomic_open() without opening the file
+ *
+ * @od: opaque open data
+ * @dentry: dentry or NULL (as returned from ->lookup())
+ *
+ * This can be used to set the result of a successful lookup in ->atomic_open().
+ * The filesystem's atomic_open() method shall return NULL after calling this.
+ */
+void finish_no_open(struct opendata *od, struct dentry *dentry)
+{
+	od->dentry = dentry;
+}
+EXPORT_SYMBOL(finish_no_open);
+
+/**
  * nameidata_to_filp - convert a nameidata to an open filp.
  * @nd: pointer to nameidata
  * @flags: open flags
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 135693e..2700bea 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -417,6 +417,7 @@ struct kstatfs;
 struct vm_area_struct;
 struct vfsmount;
 struct cred;
+struct opendata;
 
 extern void __init inode_init(void);
 extern void __init inode_init_early(void);
@@ -1659,6 +1660,9 @@ struct inode_operations {
 	void (*truncate_range)(struct inode *, loff_t, loff_t);
 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
 		      u64 len);
+	struct file * (*atomic_open)(struct inode *, struct dentry *,
+				     struct opendata *, unsigned open_flag,
+				     umode_t create_mode, bool *created);
 } ____cacheline_aligned;
 
 struct seq_file;
@@ -2020,6 +2024,9 @@ extern struct file * dentry_open(struct dentry *, struct vfsmount *, int,
 				 const struct cred *);
 extern int filp_close(struct file *, fl_owner_t id);
 extern char * getname(const char __user *);
+extern struct file *finish_open(struct opendata *od, struct dentry *dentry,
+				int (*open)(struct inode *, struct file *));
+extern void finish_no_open(struct opendata *od, struct dentry *dentry);
 
 /* fs/ioctl.c */
 
-- 
1.7.7

[PATCH 23/34] nfs: implement i_op->atomic_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Replace NFS4 specific ->lookup implementation with ->atomic_open impelementation
and use the generic nfs_lookup for other lookups.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/nfs/dir.c |  183 +++++++++++++++++++++++++++++++---------------------------
 1 files changed, 97 insertions(+), 86 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 10ce72e..1fb5d66 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -111,11 +111,15 @@ const struct inode_operations nfs3_dir_inode_operations = {
 
 #ifdef CONFIG_NFS_V4
 
-static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
-static int nfs_open_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd);
+static struct file *nfs_atomic_open(struct inode *, struct dentry *,
+				    struct opendata *, unsigned, umode_t,
+				    bool *);
+static int nfs4_create(struct inode *dir, struct dentry *dentry,
+		       umode_t mode, struct nameidata *nd);
 const struct inode_operations nfs4_dir_inode_operations = {
-	.create		= nfs_open_create,
-	.lookup		= nfs_atomic_lookup,
+	.create		= nfs4_create,
+	.lookup		= nfs_lookup,
+	.atomic_open	= nfs_atomic_open,
 	.link		= nfs_link,
 	.unlink		= nfs_unlink,
 	.symlink	= nfs_symlink,
@@ -1377,120 +1381,132 @@ static int do_open(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
+static struct file *nfs_finish_open(struct nfs_open_context *ctx,
+				    struct dentry *dentry,
+				    struct opendata *od, unsigned open_flags)
 {
 	struct file *filp;
-	int ret = 0;
+	int err;
+
+	if (ctx->dentry != dentry) {
+		dput(ctx->dentry);
+		ctx->dentry = dget(dentry);
+	}
 
 	/* If the open_intent is for execute, we have an extra check to make */
 	if (ctx->mode & FMODE_EXEC) {
-		ret = nfs_may_open(ctx->dentry->d_inode,
-				ctx->cred,
-				nd->intent.open.flags);
-		if (ret < 0)
+		err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
+		if (err < 0) {
+			filp = ERR_PTR(err);
 			goto out;
+		}
 	}
-	filp = lookup_instantiate_filp(nd, ctx->dentry, do_open);
-	if (IS_ERR(filp))
-		ret = PTR_ERR(filp);
-	else
+
+	filp = finish_open(od, dentry, do_open);
+	if (!IS_ERR(filp))
 		nfs_file_set_open_context(filp, ctx);
+
 out:
 	put_nfs_open_context(ctx);
-	return ret;
+	return filp;
 }
 
-static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+static struct file *nfs_atomic_open(struct inode *dir, struct dentry *dentry,
+				    struct opendata *od, unsigned open_flags,
+				    umode_t mode, bool *created)
 {
 	struct nfs_open_context *ctx;
-	struct iattr attr;
-	struct dentry *res = NULL;
+	struct dentry *res;
+	struct iattr attr = { .ia_valid = 0 };
 	struct inode *inode;
-	int open_flags;
+	struct file *filp;
 	int err;
 
-	dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
+	/* Expect a negative dentry */
+	BUG_ON(dentry->d_inode);
+
+	dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
 			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
 
-	/* Check that we are indeed trying to open this file */
-	if (!is_atomic_open(nd))
+	/* NFS only supports OPEN on regular files */
+	if ((open_flags & O_DIRECTORY)) {
+		err = -ENOENT;
+		if (!d_unhashed(dentry)) {
+			/*
+			 * Hashed negative dentry with O_DIRECTORY: dentry was
+			 * revalidated and is fine, no need to perform lookup
+			 * again
+			 */
+			goto out_err;
+		}
 		goto no_open;
-
-	if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
-		res = ERR_PTR(-ENAMETOOLONG);
-		goto out;
 	}
 
-	/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
-	 * the dentry. */
-	if (nd->flags & LOOKUP_EXCL) {
-		d_instantiate(dentry, NULL);
-		goto out;
-	}
-
-	open_flags = nd->intent.open.flags;
-	attr.ia_valid = 0;
-
-	ctx = create_nfs_open_context(dentry, open_flags);
-	res = ERR_CAST(ctx);
-	if (IS_ERR(ctx))
-		goto out;
+	err = -ENAMETOOLONG;
+	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+		goto out_err;
 
-	if (nd->flags & LOOKUP_CREATE) {
-		attr.ia_mode = nd->intent.open.create_mode;
+	if (open_flags & O_CREAT) {
 		attr.ia_valid |= ATTR_MODE;
-		attr.ia_mode &= ~current_umask();
-	} else
-		open_flags &= ~(O_EXCL | O_CREAT);
-
+		attr.ia_mode = mode & ~current_umask();
+	}
 	if (open_flags & O_TRUNC) {
 		attr.ia_valid |= ATTR_SIZE;
 		attr.ia_size = 0;
 	}
 
-	/* Open the file on the server */
+	ctx = create_nfs_open_context(dentry, open_flags);
+	err = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out_err;
+
 	nfs_block_sillyrename(dentry->d_parent);
 	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
+	d_drop(dentry);
 	if (IS_ERR(inode)) {
 		nfs_unblock_sillyrename(dentry->d_parent);
 		put_nfs_open_context(ctx);
-		switch (PTR_ERR(inode)) {
-			/* Make a negative dentry */
-			case -ENOENT:
-				d_add(dentry, NULL);
-				res = NULL;
-				goto out;
-			/* This turned out not to be a regular file */
-			case -EISDIR:
-			case -ENOTDIR:
+		err = PTR_ERR(inode);
+		switch (err) {
+		case -ENOENT:
+			d_add(dentry, NULL);
+			break;
+		case -EISDIR:
+		case -ENOTDIR:
+			goto no_open;
+		case -ELOOP:
+			if (!(open_flags & O_NOFOLLOW))
 				goto no_open;
-			case -ELOOP:
-				if (!(nd->intent.open.flags & O_NOFOLLOW))
-					goto no_open;
+			break;
 			/* case -EINVAL: */
-			default:
-				res = ERR_CAST(inode);
-				goto out;
+		default:
+			break;
 		}
+		goto out_err;
 	}
 	res = d_add_unique(dentry, inode);
-	nfs_unblock_sillyrename(dentry->d_parent);
-	if (res != NULL) {
-		dput(ctx->dentry);
-		ctx->dentry = dget(res);
+	if (res != NULL)
 		dentry = res;
-	}
-	err = nfs_intent_set_file(nd, ctx);
-	if (err < 0) {
-		if (res != NULL)
-			dput(res);
-		return ERR_PTR(err);
-	}
-out:
+
+	nfs_unblock_sillyrename(dentry->d_parent);
 	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-	return res;
+
+	filp = nfs_finish_open(ctx, dentry, od, open_flags);
+
+	dput(res);
+	return filp;
+
+out_err:
+	return ERR_PTR(err);
+
 no_open:
-	return nfs_lookup(dir, dentry, nd);
+	res = nfs_lookup(dir, dentry, NULL);
+	err = PTR_ERR(res);
+	if (IS_ERR(res))
+		goto out_err;
+
+	finish_no_open(od, res);
+	return NULL;
 }
 
 static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
@@ -1540,8 +1556,8 @@ no_open:
 	return nfs_lookup_revalidate(dentry, nd);
 }
 
-static int nfs_open_create(struct inode *dir, struct dentry *dentry,
-		umode_t mode, struct nameidata *nd)
+static int nfs4_create(struct inode *dir, struct dentry *dentry,
+		       umode_t mode, struct nameidata *nd)
 {
 	struct nfs_open_context *ctx = NULL;
 	struct iattr attr;
@@ -1565,19 +1581,14 @@ static int nfs_open_create(struct inode *dir, struct dentry *dentry,
 	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
 	if (error != 0)
 		goto out_put_ctx;
-	if (nd) {
-		error = nfs_intent_set_file(nd, ctx);
-		if (error < 0)
-			goto out_err;
-	} else {
-		put_nfs_open_context(ctx);
-	}
+
+	put_nfs_open_context(ctx);
+
 	return 0;
 out_put_ctx:
 	put_nfs_open_context(ctx);
 out_err_drop:
 	d_drop(dentry);
-out_err:
 	return error;
 }
 
-- 
1.7.7

[PATCH 24/34] nfs: clean up ->create in nfs_rpc_ops

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Don't pass nfs_open_context() to ->create().  Only the NFS4 implementation
needed that and only because it wanted to return an open file using open
intents.  That task has been replaced by ->atomic_open so it is not necessary
anymore to pass the context to the create rpc operation.

Despite nfs4_proc_create apparently being okay with a NULL context it Oopses
somewhere down the call chain.  So allocate a context here.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/nfs/dir.c            |   42 ++----------------------------------------
 fs/nfs/nfs3proc.c       |    2 +-
 fs/nfs/nfs4proc.c       |   37 ++++++++++---------------------------
 fs/nfs/proc.c           |    2 +-
 include/linux/nfs_xdr.h |    2 +-
 5 files changed, 15 insertions(+), 70 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 1fb5d66..8bfced6 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -114,10 +114,8 @@ const struct inode_operations nfs3_dir_inode_operations = {
 static struct file *nfs_atomic_open(struct inode *, struct dentry *,
 				    struct opendata *, unsigned, umode_t,
 				    bool *);
-static int nfs4_create(struct inode *dir, struct dentry *dentry,
-		       umode_t mode, struct nameidata *nd);
 const struct inode_operations nfs4_dir_inode_operations = {
-	.create		= nfs4_create,
+	.create		= nfs_create,
 	.lookup		= nfs_lookup,
 	.atomic_open	= nfs_atomic_open,
 	.link		= nfs_link,
@@ -1556,42 +1554,6 @@ no_open:
 	return nfs_lookup_revalidate(dentry, nd);
 }
 
-static int nfs4_create(struct inode *dir, struct dentry *dentry,
-		       umode_t mode, struct nameidata *nd)
-{
-	struct nfs_open_context *ctx = NULL;
-	struct iattr attr;
-	int error;
-	int open_flags = O_CREAT|O_EXCL;
-
-	dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
-			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
-
-	attr.ia_mode = mode;
-	attr.ia_valid = ATTR_MODE;
-
-	if (nd)
-		open_flags = nd->intent.open.flags;
-
-	ctx = create_nfs_open_context(dentry, open_flags);
-	error = PTR_ERR(ctx);
-	if (IS_ERR(ctx))
-		goto out_err_drop;
-
-	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
-	if (error != 0)
-		goto out_put_ctx;
-
-	put_nfs_open_context(ctx);
-
-	return 0;
-out_put_ctx:
-	put_nfs_open_context(ctx);
-out_err_drop:
-	d_drop(dentry);
-	return error;
-}
-
 #endif /* CONFIG_NFSV4 */
 
 /*
@@ -1658,7 +1620,7 @@ static int nfs_create(struct inode *dir, struct dentry *dentry,
 	if (nd)
 		open_flags = nd->intent.open.flags;
 
-	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL);
+	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
 	if (error != 0)
 		goto out_err;
 	return 0;
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 5242eae..dd62b6e 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -314,7 +314,7 @@ static void nfs3_free_createdata(struct nfs3_createdata *data)
  */
 static int
 nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
-		 int flags, struct nfs_open_context *ctx)
+		 int flags)
 {
 	struct nfs3_createdata *data;
 	umode_t mode = sattr->ia_mode;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f82bde0..5750e9c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2676,37 +2676,22 @@ static int nfs4_proc_readlink(struct inode *inode, struct page *page,
 }
 
 /*
- * Got race?
- * We will need to arrange for the VFS layer to provide an atomic open.
- * Until then, this create/open method is prone to inefficiency and race
- * conditions due to the lookup, create, and open VFS calls from sys_open()
- * placed on the wire.
- *
- * Given the above sorry state of affairs, I'm simply sending an OPEN.
- * The file will be opened again in the subsequent VFS open call
- * (nfs4_proc_file_open).
- *
- * The open for read will just hang around to be used by any process that
- * opens the file O_RDONLY. This will all be resolved with the VFS changes.
+ * This is just for mknod.  open(O_CREAT) will always do ->open_context().
  */
-
 static int
 nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
-                 int flags, struct nfs_open_context *ctx)
+		 int flags)
 {
-	struct dentry *de = dentry;
+	struct nfs_open_context *ctx;
 	struct nfs4_state *state;
-	struct rpc_cred *cred = NULL;
-	fmode_t fmode = 0;
 	int status = 0;
 
-	if (ctx != NULL) {
-		cred = ctx->cred;
-		de = ctx->dentry;
-		fmode = ctx->mode;
-	}
+	ctx = alloc_nfs_open_context(dentry, FMODE_READ);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
 	sattr->ia_mode &= ~current_umask();
-	state = nfs4_do_open(dir, de, fmode, flags, sattr, cred);
+	state = nfs4_do_open(dir, dentry, ctx->mode, flags, sattr, ctx->cred);
 	d_drop(dentry);
 	if (IS_ERR(state)) {
 		status = PTR_ERR(state);
@@ -2714,11 +2699,9 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 	}
 	d_add(dentry, igrab(state->inode));
 	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-	if (ctx != NULL)
-		ctx->state = state;
-	else
-		nfs4_close_sync(state, fmode);
+	ctx->state = state;
 out:
+	put_nfs_open_context(ctx);
 	return status;
 }
 
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index b63b6f4..f3909ed 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -259,7 +259,7 @@ static void nfs_free_createdata(const struct nfs_createdata *data)
 
 static int
 nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
-		int flags, struct nfs_open_context *ctx)
+		int flags)
 {
 	struct nfs_createdata *data;
 	struct rpc_message msg = {
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index bfd0d1b..f2b5d09 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1239,7 +1239,7 @@ struct nfs_rpc_ops {
 	int	(*readlink)(struct inode *, struct page *, unsigned int,
 			    unsigned int);
 	int	(*create)  (struct inode *, struct dentry *,
-			    struct iattr *, int, struct nfs_open_context *);
+			    struct iattr *, int);
 	int	(*remove)  (struct inode *, struct qstr *);
 	void	(*unlink_setup)  (struct rpc_message *, struct inode *dir);
 	void	(*unlink_rpc_prepare) (struct rpc_task *, struct nfs_unlinkdata *);
-- 
1.7.7

[PATCH 25/34] nfs: don't use nd->intent.open.flags

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Instead check LOOKUP_EXCL in nd->flags, which is basically what the open intent
flags were used for.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/nfs/dir.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8bfced6..73137be 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1512,7 +1512,7 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 	struct dentry *parent = NULL;
 	struct inode *inode;
 	struct inode *dir;
-	int openflags, ret = 0;
+	int ret = 0;
 
 	if (nd->flags & LOOKUP_RCU)
 		return -ECHILD;
@@ -1536,9 +1536,8 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 	/* NFS only supports OPEN on regular files */
 	if (!S_ISREG(inode->i_mode))
 		goto no_open_dput;
-	openflags = nd->intent.open.flags;
 	/* We cannot do exclusive creation on a positive dentry */
-	if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+	if (nd && nd->flags & LOOKUP_EXCL)
 		goto no_open_dput;
 
 	/* Let f_op->open() actually open (and revalidate) the file */
@@ -1617,8 +1616,8 @@ static int nfs_create(struct inode *dir, struct dentry *dentry,
 	attr.ia_mode = mode;
 	attr.ia_valid = ATTR_MODE;
 
-	if (nd)
-		open_flags = nd->intent.open.flags;
+	if (nd && !(nd->flags & LOOKUP_EXCL))
+		open_flags = O_CREAT;
 
 	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
 	if (error != 0)
-- 
1.7.7

[PATCH 26/34] nfs: don't use intents for checking atomic open

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

is_atomic_open() is now only used by nfs4_lookup_revalidate() to check whether
it's okay to skip normal revalidation.

It does a racy check for mount read-onlyness and falls back to normal
revalidation if the open would fail.  This makes little sense now that this
function isn't used for determining whether to actually open the file or not.

The d_mountpoint() check still makes sense since it is an indication that we
might be following a mount and so open may not revalidate the dentry.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/nfs/dir.c |   24 ++++--------------------
 1 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 73137be..24cd7b7 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1340,24 +1340,6 @@ const struct dentry_operations nfs4_dentry_operations = {
 	.d_release	= nfs_d_release,
 };
 
-/*
- * Use intent information to determine whether we need to substitute
- * the NFSv4-style stateful OPEN for the LOOKUP call
- */
-static int is_atomic_open(struct nameidata *nd)
-{
-	if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
-		return 0;
-	/* NFS does not (yet) have a stateful open for directories */
-	if (nd->flags & LOOKUP_DIRECTORY)
-		return 0;
-	/* Are we trying to write to a read only partition? */
-	if (__mnt_is_readonly(nd->path.mnt) &&
-	    (nd->intent.open.flags & (O_CREAT|O_TRUNC|O_ACCMODE)))
-		return 0;
-	return 1;
-}
-
 static fmode_t flags_to_mode(int flags)
 {
 	fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
@@ -1517,10 +1499,12 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
 	if (nd->flags & LOOKUP_RCU)
 		return -ECHILD;
 
-	inode = dentry->d_inode;
-	if (!is_atomic_open(nd) || d_mountpoint(dentry))
+	if (!(nd->flags & LOOKUP_OPEN) || (nd->flags & LOOKUP_DIRECTORY))
+		goto no_open;
+	if (d_mountpoint(dentry))
 		goto no_open;
 
+	inode = dentry->d_inode;
 	parent = dget_parent(dentry);
 	dir = parent->d_inode;
 
-- 
1.7.7

[PATCH 27/34] fuse: implement i_op->atomic_create()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Replace fuse's ->create implementation with a ->atomic_create implementation.
No functionality is changed.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/fuse/dir.c |   97 ++++++++++++++++++++++++++++++++++++++++----------------
 1 files changed, 69 insertions(+), 28 deletions(-)

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 2066328..75e5142 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -369,8 +369,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
  * If the filesystem doesn't support this, then fall back to separate
  * 'mknod' + 'open' requests.
  */
-static int fuse_create_open(struct inode *dir, struct dentry *entry,
-			    umode_t mode, struct nameidata *nd)
+static struct file *fuse_create_open(struct inode *dir, struct dentry *entry,
+				     struct opendata *od, unsigned flags,
+				     umode_t mode)
 {
 	int err;
 	struct inode *inode;
@@ -382,17 +383,15 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	struct fuse_entry_out outentry;
 	struct fuse_file *ff;
 	struct file *file;
-	int flags = nd->intent.open.flags;
-
-	if (fc->no_create)
-		return -ENOSYS;
 
+	err = -EINVAL;
 	if (flags & O_DIRECT)
-		return -EINVAL;
+		goto out_err;
 
 	forget = fuse_alloc_forget();
+	err = -ENOMEM;
 	if (!forget)
-		return -ENOMEM;
+		goto out_err;
 
 	req = fuse_get_req(fc);
 	err = PTR_ERR(req);
@@ -431,11 +430,8 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	req->out.args[1].value = &outopen;
 	fuse_request_send(fc, req);
 	err = req->out.h.error;
-	if (err) {
-		if (err == -ENOSYS)
-			fc->no_create = 1;
+	if (err)
 		goto out_free_ff;
-	}
 
 	err = -EIO;
 	if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
@@ -451,28 +447,78 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
 		fuse_sync_release(ff, flags);
 		fuse_queue_forget(fc, forget, outentry.nodeid, 1);
-		return -ENOMEM;
+		err = -ENOMEM;
+		goto out_err;
 	}
 	kfree(forget);
 	d_instantiate(entry, inode);
 	fuse_change_entry_timeout(entry, &outentry);
 	fuse_invalidate_attr(dir);
-	file = lookup_instantiate_filp(nd, entry, generic_file_open);
+	file = finish_open(od, entry, generic_file_open);
 	if (IS_ERR(file)) {
 		fuse_sync_release(ff, flags);
-		return PTR_ERR(file);
+	} else {
+		file->private_data = fuse_file_get(ff);
+		fuse_finish_open(inode, file);
 	}
-	file->private_data = fuse_file_get(ff);
-	fuse_finish_open(inode, file);
-	return 0;
+	return file;
 
- out_free_ff:
+out_free_ff:
 	fuse_file_free(ff);
- out_put_request:
+out_put_request:
 	fuse_put_request(fc, req);
- out_put_forget_req:
+out_put_forget_req:
 	kfree(forget);
-	return err;
+out_err:
+	return ERR_PTR(err);
+}
+
+static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+static struct file *fuse_atomic_open(struct inode *dir, struct dentry *entry,
+				     struct opendata *od, unsigned flags,
+				     umode_t mode, bool *created)
+{
+	int err;
+	struct fuse_conn *fc = get_fuse_conn(dir);
+	struct file *file;
+	struct dentry *res = NULL;
+
+	if (d_unhashed(entry)) {
+		res = fuse_lookup(dir, entry, NULL);
+		if (IS_ERR(res))
+			return ERR_CAST(res);
+
+		if (res)
+			entry = res;
+	}
+
+	if (!(flags & O_CREAT) || entry->d_inode)
+		goto no_open;
+
+	/* Only creates */
+	*created = true;
+
+	if (fc->no_create)
+		goto mknod;
+
+	file = fuse_create_open(dir, entry, od, flags, mode);
+	if (PTR_ERR(file) == -ENOSYS) {
+		fc->no_create = 1;
+		goto mknod;
+	}
+out_dput:
+	dput(res);
+	return file;
+
+mknod:
+	err = fuse_mknod(dir, entry, mode, 0);
+	if (err) {
+		file = ERR_PTR(err);
+		goto out_dput;
+	}
+no_open:
+	finish_no_open(od, res);
+	return NULL;
 }
 
 /*
@@ -576,12 +622,6 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
 static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
 		       struct nameidata *nd)
 {
-	if (nd) {
-		int err = fuse_create_open(dir, entry, mode, nd);
-		if (err != -ENOSYS)
-			return err;
-		/* Fall back on mknod */
-	}
 	return fuse_mknod(dir, entry, mode, 0);
 }
 
@@ -1632,6 +1672,7 @@ static const struct inode_operations fuse_dir_inode_operations = {
 	.link		= fuse_link,
 	.setattr	= fuse_setattr,
 	.create		= fuse_create,
+	.atomic_open	= fuse_atomic_open,
 	.mknod		= fuse_mknod,
 	.permission	= fuse_permission,
 	.getattr	= fuse_getattr,
-- 
1.7.7

Re: [PATCH 27/34] fuse: implement i_op->atomic_create()

[Christoph Hellwig]

On Thu, Apr 05, 2012 at 04:58:53PM +0200, Miklos Szeredi wrote:
> From: Miklos Szeredi <mszeredi@suse.cz>
> 
> Replace fuse's ->create implementation with a ->atomic_create implementation.
> No functionality is changed.

atomic_create is atomic_open now.  Same applies for the subject and
commit log in a couple of the following patches.

Re: [PATCH 27/34] fuse: implement i_op->atomic_create()

[Miklos Szeredi]

On Thu, Apr 5, 2012 at 5:41 PM, Christoph Hellwig <hch@infradead.org> wrote:
> On Thu, Apr 05, 2012 at 04:58:53PM +0200, Miklos Szeredi wrote:
>> From: Miklos Szeredi <mszeredi@suse.cz>
>>
>> Replace fuse's ->create implementation with a ->atomic_create implementation.
>> No functionality is changed.
>
> atomic_create is atomic_open now.  Same applies for the subject and
> commit log in a couple of the following patches.
>

Thought I fixed those.  Anyway, fixed now.  Thanks.

Miklos

[PATCH 28/34] cifs: implement i_op->atomic_open() and i_op->atomic_create()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Replace CIFS's ->create operation with ->atomic_open and ->atomic_create.  Also
move the relevant code from ->lookup into the create function.

CIFS currently only does atomic open for O_CREAT, but it wants to do that as
early as possible, without first calling ->lookup, so it uses ->atomic_open,
just like NFS.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/cifs/cifsfs.c |    1 +
 fs/cifs/cifsfs.h |    3 +
 fs/cifs/dir.c    |  437 ++++++++++++++++++++++++++++++------------------------
 3 files changed, 245 insertions(+), 196 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index d342128..74c2bf2 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -764,6 +764,7 @@ struct file_system_type cifs_fs_type = {
 };
 const struct inode_operations cifs_dir_inode_ops = {
 	.create = cifs_create,
+	.atomic_open = cifs_atomic_open,
 	.lookup = cifs_lookup,
 	.getattr = cifs_getattr,
 	.unlink = cifs_unlink,
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index d1389bb..c960c20 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -46,6 +46,9 @@ extern const struct inode_operations cifs_dir_inode_ops;
 extern struct inode *cifs_root_iget(struct super_block *);
 extern int cifs_create(struct inode *, struct dentry *, umode_t,
 		       struct nameidata *);
+extern struct file *cifs_atomic_open(struct inode *, struct dentry *,
+				     struct opendata *, unsigned, umode_t,
+				     bool *);
 extern struct dentry *cifs_lookup(struct inode *, struct dentry *,
 				  struct nameidata *);
 extern int cifs_unlink(struct inode *dir, struct dentry *dentry);
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index d172c8e..9682413 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -133,108 +133,141 @@ cifs_bp_rename_retry:
 	return full_path;
 }
 
+/*
+ * Don't allow the separator character in a path component.
+ * The VFS will not allow "/", but "\" is allowed by posix.
+ */
+static int
+check_name(struct dentry *direntry)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	int i;
+
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
+		for (i = 0; i < direntry->d_name.len; i++) {
+			if (direntry->d_name.name[i] == '\\') {
+				cFYI(1, "Invalid file name");
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
+
 /* Inode operations in similar order to how they appear in Linux file fs.h */
 
-int
-cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
-		struct nameidata *nd)
+static int cifs_do_create(struct inode *inode, struct dentry *direntry,
+			  int xid, struct tcon_link *tlink, unsigned oflags,
+			  umode_t mode, __u32 *oplock, __u16 *fileHandle,
+			  bool *created)
 {
 	int rc = -ENOENT;
-	int xid;
 	int create_options = CREATE_NOT_DIR;
-	__u32 oplock = 0;
-	int oflags;
-	/*
-	 * BB below access is probably too much for mknod to request
-	 *    but we have to do query and setpathinfo so requesting
-	 *    less could fail (unless we want to request getatr and setatr
-	 *    permissions (only).  At least for POSIX we do not have to
-	 *    request so much.
-	 */
-	int desiredAccess = GENERIC_READ | GENERIC_WRITE;
-	__u16 fileHandle;
-	struct cifs_sb_info *cifs_sb;
-	struct tcon_link *tlink;
-	struct cifs_tcon *tcon;
+	int desiredAccess;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct cifs_tcon *tcon = tlink_tcon(tlink);
 	char *full_path = NULL;
 	FILE_ALL_INFO *buf = NULL;
 	struct inode *newinode = NULL;
-	int disposition = FILE_OVERWRITE_IF;
-
-	xid = GetXid();
-
-	cifs_sb = CIFS_SB(inode->i_sb);
-	tlink = cifs_sb_tlink(cifs_sb);
-	if (IS_ERR(tlink)) {
-		FreeXid(xid);
-		return PTR_ERR(tlink);
-	}
-	tcon = tlink_tcon(tlink);
+	int disposition;
 
+	*oplock = 0;
 	if (tcon->ses->server->oplocks)
-		oplock = REQ_OPLOCK;
-
-	if (nd)
-		oflags = nd->intent.open.file->f_flags;
-	else
-		oflags = O_RDONLY | O_CREAT;
+		*oplock = REQ_OPLOCK;
 
 	full_path = build_path_from_dentry(direntry);
 	if (full_path == NULL) {
 		rc = -ENOMEM;
-		goto cifs_create_out;
+		goto out;
 	}
 
 	if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
+	    !tcon->broken_posix_open &&
 	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 		rc = cifs_posix_open(full_path, &newinode,
-			inode->i_sb, mode, oflags, &oplock, &fileHandle, xid);
-		/* EIO could indicate that (posix open) operation is not
-		   supported, despite what server claimed in capability
-		   negotiation.  EREMOTE indicates DFS junction, which is not
-		   handled in posix open */
+			inode->i_sb, mode, oflags, oplock, fileHandle, xid);
+		switch (rc) {
+		case 0:
+			if (newinode == NULL) {
+				/* query inode info */
+				goto cifs_create_get_file_info;
+			}
 
-		if (rc == 0) {
-			if (newinode == NULL) /* query inode info */
+			if (!S_ISREG(newinode->i_mode)) {
+				/*
+				 * The server may allow us to open things like
+				 * FIFOs, but the client isn't set up to deal
+				 * with that. If it's not a regular file, just
+				 * close it and proceed as if it were a normal
+				 * lookup.
+				 */
+				CIFSSMBClose(xid, tcon, *fileHandle);
 				goto cifs_create_get_file_info;
-			else /* success, no need to query */
-				goto cifs_create_set_dentry;
-		} else if ((rc != -EIO) && (rc != -EREMOTE) &&
-			 (rc != -EOPNOTSUPP) && (rc != -EINVAL))
-			goto cifs_create_out;
-		/* else fallthrough to retry, using older open call, this is
-		   case where server does not support this SMB level, and
-		   falsely claims capability (also get here for DFS case
-		   which should be rare for path not covered on files) */
-	}
+			}
+			/* success, no need to query */
+			goto cifs_create_set_dentry;
+
+		case -ENOENT:
+			goto cifs_create_get_file_info;
+
+		case -EIO:
+		case -EINVAL:
+			/*
+			 * EIO could indicate that (posix open) operation is not
+			 * supported, despite what server claimed in capability
+			 * negotiation.
+			 *
+			 * POSIX open in samba versions 3.3.1 and earlier could
+			 * incorrectly fail with invalid parameter.
+			 */
+			tcon->broken_posix_open = true;
+			break;
 
-	if (nd) {
-		/* if the file is going to stay open, then we
-		   need to set the desired access properly */
-		desiredAccess = 0;
-		if (OPEN_FMODE(oflags) & FMODE_READ)
-			desiredAccess |= GENERIC_READ; /* is this too little? */
-		if (OPEN_FMODE(oflags) & FMODE_WRITE)
-			desiredAccess |= GENERIC_WRITE;
+		case -EREMOTE:
+		case -EOPNOTSUPP:
+			/*
+			 * EREMOTE indicates DFS junction, which is not handled
+			 * in posix open.  If either that or op not supported
+			 * returned, follow the normal lookup.
+			 */
+			break;
 
-		if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
-			disposition = FILE_CREATE;
-		else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
-			disposition = FILE_OVERWRITE_IF;
-		else if ((oflags & O_CREAT) == O_CREAT)
-			disposition = FILE_OPEN_IF;
-		else
-			cFYI(1, "Create flag not set in create function");
+		default:
+			goto out;
+		}
+		/*
+		 * fallthrough to retry, using older open call, this is case
+		 * where server does not support this SMB level, and falsely
+		 * claims capability (also get here for DFS case which should be
+		 * rare for path not covered on files)
+		 */
 	}
 
+	desiredAccess = 0;
+	if (OPEN_FMODE(oflags) & FMODE_READ)
+		desiredAccess |= GENERIC_READ; /* is this too little? */
+	if (OPEN_FMODE(oflags) & FMODE_WRITE)
+		desiredAccess |= GENERIC_WRITE;
+
+	disposition = FILE_OVERWRITE_IF;
+	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
+		disposition = FILE_CREATE;
+	else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
+		disposition = FILE_OVERWRITE_IF;
+	else if ((oflags & O_CREAT) == O_CREAT)
+		disposition = FILE_OPEN_IF;
+	else
+		cFYI(1, "Create flag not set in create function");
+
 	/* BB add processing to set equivalent of mode - e.g. via CreateX with
 	   ACLs */
 
 	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 	if (buf == NULL) {
 		rc = -ENOMEM;
-		goto cifs_create_out;
+		goto out;
 	}
 
 	/*
@@ -250,7 +283,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 	if (tcon->ses->capabilities & CAP_NT_SMBS)
 		rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
 			 desiredAccess, create_options,
-			 &fileHandle, &oplock, buf, cifs_sb->local_nls,
+			 fileHandle, oplock, buf, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	else
 		rc = -EIO; /* no NT SMB support fall into legacy open below */
@@ -259,17 +292,17 @@ cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 		/* old server, retry the open legacy style */
 		rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
 			desiredAccess, create_options,
-			&fileHandle, &oplock, buf, cifs_sb->local_nls,
+			fileHandle, oplock, buf, cifs_sb->local_nls,
 			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	}
 	if (rc) {
 		cFYI(1, "cifs_create returned 0x%x", rc);
-		goto cifs_create_out;
+		goto out;
 	}
 
 	/* If Open reported that we actually created a file
 	   then we now have to set the mode if possible */
-	if ((tcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
+	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 		struct cifs_unix_set_info_args args = {
 				.mode	= mode,
 				.ctime	= NO_CHANGE_64,
@@ -278,6 +311,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 				.device	= 0,
 		};
 
+		*created = true;
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 			args.uid = (__u64) current_fsuid();
 			if (inode->i_mode & S_ISGID)
@@ -288,7 +322,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 			args.uid = NO_CHANGE_64;
 			args.gid = NO_CHANGE_64;
 		}
-		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fileHandle,
+		CIFSSMBUnixSetFileInfo(xid, tcon, &args, *fileHandle,
 					current->tgid);
 	} else {
 		/* BB implement mode setting via Windows security
@@ -305,11 +339,11 @@ cifs_create_get_file_info:
 					      inode->i_sb, xid);
 	else {
 		rc = cifs_get_inode_info(&newinode, full_path, buf,
-					 inode->i_sb, xid, &fileHandle);
+					 inode->i_sb, xid, fileHandle);
 		if (newinode) {
 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 				newinode->i_mode = mode;
-			if ((oplock & CIFS_CREATE_ACTION) &&
+			if ((*oplock & CIFS_CREATE_ACTION) &&
 			    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
 				newinode->i_uid = current_fsuid();
 				if (inode->i_mode & S_ISGID)
@@ -321,37 +355,139 @@ cifs_create_get_file_info:
 	}
 
 cifs_create_set_dentry:
-	if (rc == 0)
-		d_instantiate(direntry, newinode);
-	else
+	if (rc != 0) {
 		cFYI(1, "Create worked, get_inode_info failed rc = %d", rc);
+		goto out;
+	}
+	d_drop(direntry);
+	d_add(direntry, newinode);
 
-	if (newinode && nd) {
-		struct cifsFileInfo *pfile_info;
-		struct file *filp;
+	/* ENOENT for create?  How weird... */
+	rc = -ENOENT;
+	if (!newinode) {
+		CIFSSMBClose(xid, tcon, *fileHandle);
+		goto out;
+	}
+	rc = 0;
 
-		filp = lookup_instantiate_filp(nd, direntry, generic_file_open);
-		if (IS_ERR(filp)) {
-			rc = PTR_ERR(filp);
-			CIFSSMBClose(xid, tcon, fileHandle);
-			goto cifs_create_out;
-		}
+out:
+	kfree(buf);
+	kfree(full_path);
+	return rc;
+}
 
-		pfile_info = cifs_new_fileinfo(fileHandle, filp, tlink, oplock);
-		if (pfile_info == NULL) {
-			fput(filp);
-			CIFSSMBClose(xid, tcon, fileHandle);
-			rc = -ENOMEM;
-		}
-	} else {
+struct file *
+cifs_atomic_open(struct inode *inode, struct dentry *direntry,
+		 struct opendata *od, unsigned oflags, umode_t mode,
+		 bool *created)
+{
+	int rc;
+	int xid;
+	struct tcon_link *tlink;
+	struct cifs_tcon *tcon;
+	__u16 fileHandle;
+	__u32 oplock;
+	struct file *filp;
+	struct cifsFileInfo *pfile_info;
+
+	/* Posix open is only called (at lookup time) for file create now.  For
+	 * opens (rather than creates), because we do not know if it is a file
+	 * or directory yet, and current Samba no longer allows us to do posix
+	 * open on dirs, we could end up wasting an open call on what turns out
+	 * to be a dir. For file opens, we wait to call posix open till
+	 * cifs_open.  It could be added to atomic_open in the future but the
+	 * performance tradeoff of the extra network request when EISDIR or
+	 * EACCES is returned would have to be weighed against the 50% reduction
+	 * in network traffic in the other paths.
+	 */
+	if (!(oflags & O_CREAT)) {
+		struct dentry *res = cifs_lookup(inode, direntry, NULL);
+		if (IS_ERR(res))
+			return ERR_CAST(res);
+
+		finish_no_open(od, res);
+		return NULL;
+	}
+
+	rc = check_name(direntry);
+	if (rc)
+		return ERR_PTR(rc);
+
+	xid = GetXid();
+
+	cFYI(1, "parent inode = 0x%p name is: %s and dentry = 0x%p",
+	     inode, direntry->d_name.name, direntry);
+
+	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
+	filp = ERR_CAST(tlink);
+	if (IS_ERR(tlink))
+		goto free_xid;
+
+	tcon = tlink_tcon(tlink);
+
+	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
+			    &oplock, &fileHandle, created);
+
+	if (rc) {
+		filp = ERR_PTR(rc);
+		goto out;
+	}
+
+	filp = finish_open(od, direntry, generic_file_open);
+	if (IS_ERR(filp)) {
 		CIFSSMBClose(xid, tcon, fileHandle);
+		goto out;
 	}
 
-cifs_create_out:
-	kfree(buf);
-	kfree(full_path);
+	pfile_info = cifs_new_fileinfo(fileHandle, filp, tlink, oplock);
+	if (pfile_info == NULL) {
+		CIFSSMBClose(xid, tcon, fileHandle);
+		fput(filp);
+		filp = ERR_PTR(-ENOMEM);
+	}
+
+out:
+	cifs_put_tlink(tlink);
+free_xid:
+	FreeXid(xid);
+	return filp;
+}
+
+int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
+		struct nameidata *nd)
+{
+	int rc;
+	int xid = GetXid();
+	/*
+	 * BB below access is probably too much for mknod to request
+	 *    but we have to do query and setpathinfo so requesting
+	 *    less could fail (unless we want to request getatr and setatr
+	 *    permissions (only).  At least for POSIX we do not have to
+	 *    request so much.
+	 */
+	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
+	struct tcon_link *tlink;
+	__u16 fileHandle;
+	__u32 oplock;
+	bool created = true;
+
+	cFYI(1, "cifs_create parent inode = 0x%p name is: %s and dentry = 0x%p",
+	     inode, direntry->d_name.name, direntry);
+
+	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
+	rc = PTR_ERR(tlink);
+	if (IS_ERR(tlink))
+		goto free_xid;
+
+	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
+			    &oplock, &fileHandle, &created);
+	if (!rc)
+		CIFSSMBClose(xid, tlink_tcon(tlink), fileHandle);
+
 	cifs_put_tlink(tlink);
+free_xid:
 	FreeXid(xid);
+
 	return rc;
 }
 
@@ -492,16 +628,11 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 {
 	int xid;
 	int rc = 0; /* to get around spurious gcc warning, set to zero here */
-	__u32 oplock;
-	__u16 fileHandle = 0;
-	bool posix_open = false;
 	struct cifs_sb_info *cifs_sb;
 	struct tcon_link *tlink;
 	struct cifs_tcon *pTcon;
-	struct cifsFileInfo *cfile;
 	struct inode *newInode = NULL;
 	char *full_path = NULL;
-	struct file *filp;
 
 	xid = GetXid();
 
@@ -518,31 +649,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 	}
 	pTcon = tlink_tcon(tlink);
 
-	oplock = pTcon->ses->server->oplocks ? REQ_OPLOCK : 0;
-
-	/*
-	 * Don't allow the separator character in a path component.
-	 * The VFS will not allow "/", but "\" is allowed by posix.
-	 */
-	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
-		int i;
-		for (i = 0; i < direntry->d_name.len; i++)
-			if (direntry->d_name.name[i] == '\\') {
-				cFYI(1, "Invalid file name");
-				rc = -EINVAL;
-				goto lookup_out;
-			}
-	}
-
-	/*
-	 * O_EXCL: optimize away the lookup, but don't hash the dentry. Let
-	 * the VFS handle the create.
-	 */
-	if (nd && (nd->flags & LOOKUP_EXCL)) {
-		d_instantiate(direntry, NULL);
-		rc = 0;
+	rc = check_name(direntry);
+	if (rc)
 		goto lookup_out;
-	}
 
 	/* can not grab the rename sem here since it would
 	deadlock in the cases (beginning of sys_rename itself)
@@ -560,80 +669,16 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 	}
 	cFYI(1, "Full path: %s inode = 0x%p", full_path, direntry->d_inode);
 
-	/* Posix open is only called (at lookup time) for file create now.
-	 * For opens (rather than creates), because we do not know if it
-	 * is a file or directory yet, and current Samba no longer allows
-	 * us to do posix open on dirs, we could end up wasting an open call
-	 * on what turns out to be a dir. For file opens, we wait to call posix
-	 * open till cifs_open.  It could be added here (lookup) in the future
-	 * but the performance tradeoff of the extra network request when EISDIR
-	 * or EACCES is returned would have to be weighed against the 50%
-	 * reduction in network traffic in the other paths.
-	 */
 	if (pTcon->unix_ext) {
-		if (nd && !(nd->flags & LOOKUP_DIRECTORY) &&
-		     (nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
-		     (nd->intent.open.file->f_flags & O_CREAT)) {
-			rc = cifs_posix_open(full_path, &newInode,
-					parent_dir_inode->i_sb,
-					nd->intent.open.create_mode,
-					nd->intent.open.file->f_flags, &oplock,
-					&fileHandle, xid);
-			/*
-			 * The check below works around a bug in POSIX
-			 * open in samba versions 3.3.1 and earlier where
-			 * open could incorrectly fail with invalid parameter.
-			 * If either that or op not supported returned, follow
-			 * the normal lookup.
-			 */
-			switch (rc) {
-			case 0:
-				/*
-				 * The server may allow us to open things like
-				 * FIFOs, but the client isn't set up to deal
-				 * with that. If it's not a regular file, just
-				 * close it and proceed as if it were a normal
-				 * lookup.
-				 */
-				if (newInode && !S_ISREG(newInode->i_mode)) {
-					CIFSSMBClose(xid, pTcon, fileHandle);
-					break;
-				}
-			case -ENOENT:
-				posix_open = true;
-			case -EOPNOTSUPP:
-				break;
-			default:
-				pTcon->broken_posix_open = true;
-			}
-		}
-		if (!posix_open)
-			rc = cifs_get_inode_info_unix(&newInode, full_path,
-						parent_dir_inode->i_sb, xid);
-	} else
+		rc = cifs_get_inode_info_unix(&newInode, full_path,
+					      parent_dir_inode->i_sb, xid);
+	} else {
 		rc = cifs_get_inode_info(&newInode, full_path, NULL,
 				parent_dir_inode->i_sb, xid, NULL);
+	}
 
 	if ((rc == 0) && (newInode != NULL)) {
 		d_add(direntry, newInode);
-		if (posix_open) {
-			filp = lookup_instantiate_filp(nd, direntry,
-						       generic_file_open);
-			if (IS_ERR(filp)) {
-				rc = PTR_ERR(filp);
-				CIFSSMBClose(xid, pTcon, fileHandle);
-				goto lookup_out;
-			}
-
-			cfile = cifs_new_fileinfo(fileHandle, filp, tlink,
-						  oplock);
-			if (cfile == NULL) {
-				fput(filp);
-				CIFSSMBClose(xid, pTcon, fileHandle);
-				rc = -ENOMEM;
-				goto lookup_out;
-			}
-		}
 		/* since paths are not looked up by component - the parent
 		   directories are presumed to be good here */
 		renew_parental_timestamps(direntry);
-- 
1.7.7

[PATCH 29/34] ceph: remove unused arg from ceph_lookup_open()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

What was the purpose of this?

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/ceph/dir.c   |    4 ++--
 fs/ceph/file.c  |    3 +--
 fs/ceph/super.h |    3 +--
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 3e8094b..c4b7832 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -599,7 +599,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 	    (nd->flags & LOOKUP_OPEN) &&
 	    !(nd->intent.open.flags & O_CREAT)) {
 		int mode = nd->intent.open.create_mode & ~current->fs->umask;
-		return ceph_lookup_open(dir, dentry, nd, mode, 1);
+		return ceph_lookup_open(dir, dentry, nd, mode);
 	}
 
 	/* can we conclude ENOENT locally? */
@@ -710,7 +710,7 @@ static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 
 	if (nd) {
 		BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
-		dentry = ceph_lookup_open(dir, dentry, nd, mode, 0);
+		dentry = ceph_lookup_open(dir, dentry, nd, mode);
 		/* hrm, what should i do here if we get aliased? */
 		if (IS_ERR(dentry))
 			return PTR_ERR(dentry);
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ed72428..2fe9a3e 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -220,8 +220,7 @@ out:
  *  path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
  */
 struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-				struct nameidata *nd, int mode,
-				int locked_dir)
+				struct nameidata *nd, int mode)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 	struct ceph_mds_client *mdsc = fsc->mdsc;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index fc35036..8471db9 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -807,8 +807,7 @@ extern int ceph_copy_from_page_vector(struct page **pages,
 extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags);
 extern int ceph_open(struct inode *inode, struct file *file);
 extern struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-				       struct nameidata *nd, int mode,
-				       int locked_dir);
+				       struct nameidata *nd, int mode);
 extern int ceph_release(struct inode *inode, struct file *filp);
 
 /* dir.c */
-- 
1.7.7

[PATCH 30/34] ceph: implement i_op->atomic_open() and i_op->atomic_create()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Instead of calling ceph_lookup_open() from ->lookup and ->create, call it from
->atomic_open and ->atomic_create.

CEPH does non-create open in ->atomic_open and create-open in ->atomic_create.
To prevent unnecessary call to ->atomic_open the FS_NO_LOOKUP_CREATE flag is set
in the filesystem flags to only call ->atomic_open on non-create opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/ceph/dir.c   |   68 ++++++++++++++++++++++++++++++++++--------------------
 fs/ceph/file.c  |   21 ++++++++---------
 fs/ceph/super.h |    5 ++-
 3 files changed, 56 insertions(+), 38 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index c4b7832..75df600 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -594,14 +594,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 	if (err < 0)
 		return ERR_PTR(err);
 
-	/* open (but not create!) intent? */
-	if (nd &&
-	    (nd->flags & LOOKUP_OPEN) &&
-	    !(nd->intent.open.flags & O_CREAT)) {
-		int mode = nd->intent.open.create_mode & ~current->fs->umask;
-		return ceph_lookup_open(dir, dentry, nd, mode);
-	}
-
 	/* can we conclude ENOENT locally? */
 	if (dentry->d_inode == NULL) {
 		struct ceph_inode_info *ci = ceph_inode(dir);
@@ -642,6 +634,47 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 	return dentry;
 }
 
+struct file *ceph_atomic_open(struct inode *dir, struct dentry *dentry,
+			      struct opendata *od, unsigned flags, umode_t mode,
+			      bool *created)
+{
+	int err;
+	struct dentry *res = NULL;
+	struct file *filp;
+
+	if (!(flags & O_CREAT)) {
+		if (dentry->d_name.len > NAME_MAX)
+			return ERR_PTR(-ENAMETOOLONG);
+
+		err = ceph_init_dentry(dentry);
+		if (err < 0)
+			return ERR_PTR(err);
+
+		return ceph_lookup_open(dir, dentry, od, flags, mode);
+	}
+
+	if (d_unhashed(dentry)) {
+		res = ceph_lookup(dir, dentry, NULL);
+		if (IS_ERR(res))
+			return ERR_CAST(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* We don't deal with positive dentries here */
+	if (dentry->d_inode) {
+		finish_no_open(od, res);
+		return NULL;
+	}
+
+	*created = true;
+	filp = ceph_lookup_open(dir, dentry, od, flags, mode);
+	dput(res);
+
+	return filp;
+}
+
 /*
  * If we do a create but get no trace back from the MDS, follow up with
  * a lookup (the VFS expects us to link up the provided dentry).
@@ -702,23 +735,7 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 		       struct nameidata *nd)
 {
-	dout("create in dir %p dentry %p name '%.*s'\n",
-	     dir, dentry, dentry->d_name.len, dentry->d_name.name);
-
-	if (ceph_snap(dir) != CEPH_NOSNAP)
-		return -EROFS;
-
-	if (nd) {
-		BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
-		dentry = ceph_lookup_open(dir, dentry, nd, mode);
-		/* hrm, what should i do here if we get aliased? */
-		if (IS_ERR(dentry))
-			return PTR_ERR(dentry);
-		return 0;
-	}
-
-	/* fall back to mknod */
-	return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
+	return ceph_mknod(dir, dentry, mode, 0);
 }
 
 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
@@ -1357,6 +1374,7 @@ const struct inode_operations ceph_dir_iops = {
 	.rmdir = ceph_unlink,
 	.rename = ceph_rename,
 	.create = ceph_create,
+	.atomic_open = ceph_atomic_open,
 };
 
 const struct dentry_operations ceph_dentry_ops = {
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 2fe9a3e..bf35158 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -214,21 +214,15 @@ out:
  * may_open() fails, the struct *file gets cleaned up (i.e.
  * ceph_release gets called).  So fear not!
  */
-/*
- * flags
- *  path_lookup_open   -> LOOKUP_OPEN
- *  path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
- */
-struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-				struct nameidata *nd, int mode)
+struct file *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
+			      struct opendata *od, unsigned flags, umode_t mode)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 	struct ceph_mds_client *mdsc = fsc->mdsc;
-	struct file *file;
+	struct file *file = NULL;
 	struct ceph_mds_request *req;
 	struct dentry *ret;
 	int err;
-	int flags = nd->intent.open.flags;
 
 	dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
 	     dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
@@ -254,14 +248,19 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 		err = ceph_handle_notrace_create(dir, dentry);
 	if (err)
 		goto out;
-	file = lookup_instantiate_filp(nd, req->r_dentry, ceph_open);
+	file = finish_open(od, req->r_dentry, ceph_open);
 	if (IS_ERR(file))
 		err = PTR_ERR(file);
 out:
 	ret = ceph_finish_lookup(req, dentry, err);
 	ceph_mdsc_put_request(req);
 	dout("ceph_lookup_open result=%p\n", ret);
-	return ret;
+
+	if (IS_ERR(ret))
+		return ERR_CAST(ret);
+
+	dput(ret);
+	return err ? ERR_PTR(err) : file;
 }
 
 int ceph_release(struct inode *inode, struct file *file)
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 8471db9..e61e546 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -806,8 +806,9 @@ extern int ceph_copy_from_page_vector(struct page **pages,
 				    loff_t off, size_t len);
 extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags);
 extern int ceph_open(struct inode *inode, struct file *file);
-extern struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-				       struct nameidata *nd, int mode);
+extern struct file *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
+				     struct opendata *od, unsigned flags,
+				     umode_t mode);
 extern int ceph_release(struct inode *inode, struct file *filp);
 
 /* dir.c */
-- 
1.7.7

[PATCH 31/34] 9p: implement i_op->atomic_create()

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Replace 9p's ->create implementations with ->atomic_create implementations.  No
functionality is changed.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/9p/vfs_inode.c      |  169 +++++++++++++++++++++++++++++-------------------
 fs/9p/vfs_inode_dotl.c |   52 ++++++++++-----
 2 files changed, 137 insertions(+), 84 deletions(-)

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 014c8dd..203892d 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -712,11 +712,14 @@ error:
 }
 
 /**
- * v9fs_vfs_create - VFS hook to create files
+ * v9fs_vfs_create - VFS hook to create a regular file
+ *
+ * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
+ * for mknod(2).
+ *
  * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @mode: create permissions
- * @nd: path information
  *
  */
 
@@ -724,76 +727,19 @@ static int
 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 		struct nameidata *nd)
 {
-	int err;
-	u32 perm;
-	int flags;
-	struct file *filp;
-	struct v9fs_inode *v9inode;
-	struct v9fs_session_info *v9ses;
-	struct p9_fid *fid, *inode_fid;
-
-	err = 0;
-	fid = NULL;
-	v9ses = v9fs_inode2v9ses(dir);
-	perm = unixmode2p9mode(v9ses, mode);
-	if (nd)
-		flags = nd->intent.open.flags;
-	else
-		flags = O_RDWR;
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
+	u32 perm = unixmode2p9mode(v9ses, mode);
+	struct p9_fid *fid;
 
-	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
-				v9fs_uflags2omode(flags,
-						v9fs_proto_dotu(v9ses)));
-	if (IS_ERR(fid)) {
-		err = PTR_ERR(fid);
-		fid = NULL;
-		goto error;
-	}
+	/* P9_OEXCL? */
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
 
 	v9fs_invalidate_inode_attr(dir);
-	/* if we are opening a file, assign the open fid to the file */
-	if (nd) {
-		v9inode = V9FS_I(dentry->d_inode);
-		mutex_lock(&v9inode->v_mutex);
-		if (v9ses->cache && !v9inode->writeback_fid &&
-		    ((flags & O_ACCMODE) != O_RDONLY)) {
-			/*
-			 * clone a fid and add it to writeback_fid
-			 * we do it during open time instead of
-			 * page dirty time via write_begin/page_mkwrite
-			 * because we want write after unlink usecase
-			 * to work.
-			 */
-			inode_fid = v9fs_writeback_fid(dentry);
-			if (IS_ERR(inode_fid)) {
-				err = PTR_ERR(inode_fid);
-				mutex_unlock(&v9inode->v_mutex);
-				goto error;
-			}
-			v9inode->writeback_fid = (void *) inode_fid;
-		}
-		mutex_unlock(&v9inode->v_mutex);
-		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
-		if (IS_ERR(filp)) {
-			err = PTR_ERR(filp);
-			goto error;
-		}
-
-		filp->private_data = fid;
-#ifdef CONFIG_9P_FSCACHE
-		if (v9ses->cache)
-			v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
-#endif
-	} else
-		p9_client_clunk(fid);
+	p9_client_clunk(fid);
 
 	return 0;
-
-error:
-	if (fid)
-		p9_client_clunk(fid);
-
-	return err;
 }
 
 /**
@@ -910,6 +856,93 @@ error:
 	return ERR_PTR(result);
 }
 
+static struct file *
+v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
+		     struct opendata *od, unsigned flags, umode_t mode,
+		     bool *created)
+{
+	int err;
+	u32 perm;
+	struct file *filp;
+	struct v9fs_inode *v9inode;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid, *inode_fid;
+	struct dentry *res = NULL;
+
+	if (d_unhashed(dentry)) {
+		res = v9fs_vfs_lookup(dir, dentry, NULL);
+		if (IS_ERR(res))
+			return ERR_CAST(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT) || dentry->d_inode) {
+		finish_no_open(od, res);
+		return NULL;
+	}
+
+	err = 0;
+	fid = NULL;
+	v9ses = v9fs_inode2v9ses(dir);
+	perm = unixmode2p9mode(v9ses, mode);
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
+				v9fs_uflags2omode(flags,
+						v9fs_proto_dotu(v9ses)));
+	if (IS_ERR(fid)) {
+		err = PTR_ERR(fid);
+		fid = NULL;
+		goto error;
+	}
+
+	v9fs_invalidate_inode_attr(dir);
+	v9inode = V9FS_I(dentry->d_inode);
+	mutex_lock(&v9inode->v_mutex);
+	if (v9ses->cache && !v9inode->writeback_fid &&
+	    ((flags & O_ACCMODE) != O_RDONLY)) {
+		/*
+		 * clone a fid and add it to writeback_fid
+		 * we do it during open time instead of
+		 * page dirty time via write_begin/page_mkwrite
+		 * because we want write after unlink usecase
+		 * to work.
+		 */
+		inode_fid = v9fs_writeback_fid(dentry);
+		if (IS_ERR(inode_fid)) {
+			err = PTR_ERR(inode_fid);
+			mutex_unlock(&v9inode->v_mutex);
+			goto error;
+		}
+		v9inode->writeback_fid = (void *) inode_fid;
+	}
+	mutex_unlock(&v9inode->v_mutex);
+	filp = finish_open(od, dentry, generic_file_open);
+	if (IS_ERR(filp)) {
+		err = PTR_ERR(filp);
+		goto error;
+	}
+
+	filp->private_data = fid;
+#ifdef CONFIG_9P_FSCACHE
+	if (v9ses->cache)
+		v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
+#endif
+
+	*created = true;
+out:
+	dput(res);
+	return filp;
+
+error:
+	if (fid)
+		p9_client_clunk(fid);
+
+	filp = ERR_PTR(err);
+	goto out;
+}
+
 /**
  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
  * @i:  inode that is being unlinked
@@ -1488,6 +1521,7 @@ out:
 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
 	.create = v9fs_vfs_create,
 	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
 	.symlink = v9fs_vfs_symlink,
 	.link = v9fs_vfs_link,
 	.unlink = v9fs_vfs_unlink,
@@ -1502,6 +1536,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = {
 static const struct inode_operations v9fs_dir_inode_operations = {
 	.create = v9fs_vfs_create,
 	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
 	.unlink = v9fs_vfs_unlink,
 	.mkdir = v9fs_vfs_mkdir,
 	.rmdir = v9fs_vfs_rmdir,
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index a1e6c99..7a1b48e 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -248,7 +248,6 @@ int v9fs_open_to_dotl_flags(int flags)
  * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @mode: create permissions
- * @nd: path information
  *
  */
 
@@ -256,9 +255,16 @@ static int
 v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 		struct nameidata *nd)
 {
+	return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
+}
+
+static struct file *
+v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
+			  struct opendata *od, unsigned flags, umode_t omode,
+			  bool *created)
+{
 	int err = 0;
 	gid_t gid;
-	int flags;
 	umode_t mode;
 	char *name = NULL;
 	struct file *filp;
@@ -269,19 +275,25 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 	struct p9_fid *dfid, *ofid, *inode_fid;
 	struct v9fs_session_info *v9ses;
 	struct posix_acl *pacl = NULL, *dacl = NULL;
+	struct dentry *res = NULL;
 
-	v9ses = v9fs_inode2v9ses(dir);
-	if (nd)
-		flags = nd->intent.open.flags;
-	else {
-		/*
-		 * create call without LOOKUP_OPEN is due
-		 * to mknod of regular files. So use mknod
-		 * operation.
-		 */
-		return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
+	if (d_unhashed(dentry)) {
+		res = v9fs_vfs_lookup(dir, dentry, NULL);
+		if (IS_ERR(res))
+			return ERR_CAST(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT) || dentry->d_inode) {
+		finish_no_open(od, res);
+		return NULL;
 	}
 
+	v9ses = v9fs_inode2v9ses(dir);
+
 	name = (char *) dentry->d_name.name;
 	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
 		 name, flags, omode);
@@ -290,7 +302,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 	if (IS_ERR(dfid)) {
 		err = PTR_ERR(dfid);
 		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
-		return err;
+		goto err_return;
 	}
 
 	/* clone a fid to use for creation */
@@ -298,7 +310,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 	if (IS_ERR(ofid)) {
 		err = PTR_ERR(ofid);
 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
-		return err;
+		goto err_return;
 	}
 
 	gid = v9fs_get_fsgid_for_create(dir);
@@ -363,7 +375,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 	}
 	mutex_unlock(&v9inode->v_mutex);
 	/* Since we are opening a file, assign the open fid to the file */
-	filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
+	filp = finish_open(od, dentry, generic_file_open);
 	if (IS_ERR(filp)) {
 		err = PTR_ERR(filp);
 		goto err_clunk_old_fid;
@@ -373,7 +385,10 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 	if (v9ses->cache)
 		v9fs_cache_inode_set_cookie(inode, filp);
 #endif
-	return 0;
+	*created = true;
+out:
+	dput(res);
+	return filp;
 
 error:
 	if (fid)
@@ -382,7 +397,9 @@ err_clunk_old_fid:
 	if (ofid)
 		p9_client_clunk(ofid);
 	v9fs_set_create_acl(NULL, &dacl, &pacl);
-	return err;
+err_return:
+	filp = ERR_PTR(err);
+	goto out;
 }
 
 /**
@@ -1000,6 +1017,7 @@ out:
 
 const struct inode_operations v9fs_dir_inode_operations_dotl = {
 	.create = v9fs_vfs_create_dotl,
+	.atomic_open = v9fs_vfs_atomic_open_dotl,
 	.lookup = v9fs_vfs_lookup,
 	.link = v9fs_vfs_link_dotl,
 	.symlink = v9fs_vfs_symlink_dotl,
-- 
1.7.7

[PATCH 32/34] vfs: remove open intents from nameidata

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

All users of open intents have been converted to use ->atomic_{open,create}.

This patch gets rid of nd->intent.open and related infrastructure.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/internal.h         |    5 +--
 fs/namei.c            |   97 +++++++++++++++++++++++--------------------------
 fs/open.c             |   87 +-------------------------------------------
 include/linux/namei.h |   11 ------
 4 files changed, 49 insertions(+), 151 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 78c5c47..89c5f3a 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -84,13 +84,10 @@ extern struct super_block *user_get_super(dev_t);
 /*
  * open.c
  */
-struct nameidata;
-extern struct file *nameidata_to_filp(struct nameidata *);
-extern void release_open_intent(struct nameidata *);
 struct opendata {
 	struct dentry *dentry;
 	struct vfsmount *mnt;
-	struct file **filp;
+	struct file *filp;
 };
 struct open_flags {
 	int open_flag;
diff --git a/fs/namei.c b/fs/namei.c
index 4d505a4..b6020ca 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -476,22 +476,6 @@ err_root:
 	return -ECHILD;
 }
 
-/**
- * release_open_intent - free up open intent resources
- * @nd: pointer to nameidata
- */
-void release_open_intent(struct nameidata *nd)
-{
-	struct file *file = nd->intent.open.file;
-
-	if (file && !IS_ERR(file)) {
-		if (file->f_path.dentry == NULL)
-			put_filp(file);
-		else
-			fput(file);
-	}
-}
-
 static inline int d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	return dentry->d_op->d_revalidate(dentry, nd);
@@ -2232,7 +2216,8 @@ static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
 }
 
 static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
-				struct path *path, const struct open_flags *op,
+				struct path *path, struct opendata *od,
+				const struct open_flags *op,
 				int *want_write, bool need_lookup,
 				bool *created)
 {
@@ -2241,7 +2226,6 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 	umode_t mode;
 	int error;
 	int acc_mode;
-	struct opendata od;
 	struct file *filp;
 	int create_error = 0;
 	struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
@@ -2307,14 +2291,13 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 	if (nd->flags & LOOKUP_DIRECTORY)
 		open_flag |= O_DIRECTORY;
 
-	od.dentry = DENTRY_NOT_SET;
-	od.mnt = nd->path.mnt;
-	od.filp = &nd->intent.open.file;
-	filp = dir->i_op->atomic_open(dir, dentry, &od, open_flag, mode,
+	od->dentry = DENTRY_NOT_SET;
+	od->mnt = nd->path.mnt;
+	filp = dir->i_op->atomic_open(dir, dentry, od, open_flag, mode,
 				      created);
 	if (IS_ERR(filp)) {
-		if (WARN_ON(od.dentry != DENTRY_NOT_SET))
-			dput(od.dentry);
+		if (WARN_ON(od->dentry != DENTRY_NOT_SET))
+			dput(od->dentry);
 
 		if (create_error && PTR_ERR(filp) == -ENOENT)
 			filp = ERR_PTR(create_error);
@@ -2328,13 +2311,13 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 	}
 
 	if (!filp) {
-		if (WARN_ON(od.dentry == DENTRY_NOT_SET)) {
+		if (WARN_ON(od->dentry == DENTRY_NOT_SET)) {
 			filp = ERR_PTR(-EIO);
 			goto out;
 		}
-		if (od.dentry) {
+		if (od->dentry) {
 			dput(dentry);
-			dentry = od.dentry;
+			dentry = od->dentry;
 		}
 		goto looked_up;
 	}
@@ -2397,6 +2380,7 @@ looked_up:
  * was performed, only lookup.
  */
 static struct file *lookup_open(struct nameidata *nd, struct path *path,
+				struct opendata *od,
 				const struct open_flags *op,
 				int *want_write, bool *created)
 {
@@ -2416,7 +2400,7 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 		goto out_no_open;
 
 	if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
-		return atomic_open(nd, dentry, path, op, want_write,
+		return atomic_open(nd, dentry, path, od, op, want_write,
 				   need_lookup, created);
 	}
 
@@ -2438,7 +2422,7 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 		 * rw->ro transition does not occur between
 		 * the time when the file is created and when
 		 * a permanent write count is taken through
-		 * the 'struct file' in nameidata_to_filp().
+		 * the 'struct file' in finish_open().
 		 */
 		error = mnt_want_write(nd->path.mnt);
 		if (error)
@@ -2466,7 +2450,8 @@ out_dput:
  * Handle the last step of open()
  */
 static struct file *do_last(struct nameidata *nd, struct path *path,
-			    const struct open_flags *op, const char *pathname)
+			    struct opendata *od, const struct open_flags *op,
+			    const char *pathname)
 {
 	struct dentry *dir = nd->path.dentry;
 	int open_flag = op->open_flag;
@@ -2543,7 +2528,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
 retry_lookup:
 	mutex_lock(&dir->d_inode->i_mutex);
-	filp = lookup_open(nd, path, op, &want_write, &created);
+	filp = lookup_open(nd, path, od, op, &want_write, &created);
 	mutex_unlock(&dir->d_inode->i_mutex);
 
 	if (filp) {
@@ -2647,7 +2632,8 @@ common:
 	error = may_open(&nd->path, acc_mode, open_flag);
 	if (error)
 		goto exit;
-	filp = nameidata_to_filp(nd);
+	od->mnt = nd->path.mnt;
+	filp = finish_open(od, nd->path.dentry, NULL);
 	if (filp == ERR_PTR(-EOPENSTALE) && save_parent.dentry && !retried) {
 		BUG_ON(save_parent.dentry != dir);
 		path_put(&nd->path);
@@ -2662,6 +2648,11 @@ common:
 		retried = true;
 		goto retry_lookup;
 	}
+	if (IS_ERR(filp))
+		goto out;
+	error = open_check_o_direct(filp);
+	if (error)
+		goto exit_fput;
 opened:
 	if (!IS_ERR(filp)) {
 		error = ima_file_check(filp, op->acc_mode);
@@ -2691,24 +2682,26 @@ exit_dput:
 exit:
 	filp = ERR_PTR(error);
 	goto out;
+exit_fput:
+	fput(filp);
+	goto exit;
+
 }
 
 static struct file *path_openat(int dfd, const char *pathname,
 		struct nameidata *nd, const struct open_flags *op, int flags)
 {
 	struct file *base = NULL;
-	struct file *filp;
+	struct opendata od;
+	struct file *res;
 	struct path path;
 	int error;
 
-	filp = get_empty_filp();
-	if (!filp)
+	od.filp = get_empty_filp();
+	if (!od.filp)
 		return ERR_PTR(-ENFILE);
 
-	filp->f_flags = op->open_flag;
-	nd->intent.open.file = filp;
-	nd->intent.open.flags = open_to_namei_flags(op->open_flag);
-	nd->intent.open.create_mode = op->mode;
+	od.filp->f_flags = op->open_flag;
 
 	error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base);
 	if (unlikely(error))
@@ -2719,23 +2712,23 @@ static struct file *path_openat(int dfd, const char *pathname,
 	if (unlikely(error))
 		goto out_filp;
 
-	filp = do_last(nd, &path, op, pathname);
-	while (unlikely(!filp)) { /* trailing symlink */
+	res = do_last(nd, &path, &od, op, pathname);
+	while (unlikely(!res)) { /* trailing symlink */
 		struct path link = path;
 		void *cookie;
 		if (!(nd->flags & LOOKUP_FOLLOW)) {
 			path_put_conditional(&path, nd);
 			path_put(&nd->path);
-			filp = ERR_PTR(-ELOOP);
+			res = ERR_PTR(-ELOOP);
 			break;
 		}
 		nd->flags |= LOOKUP_PARENT;
 		nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
 		error = follow_link(&link, nd, &cookie);
 		if (unlikely(error))
-			filp = ERR_PTR(error);
+			res = ERR_PTR(error);
 		else
-			filp = do_last(nd, &path, op, pathname);
+			res = do_last(nd, &path, &od, op, pathname);
 		put_link(nd, &link, cookie);
 	}
 out:
@@ -2743,17 +2736,20 @@ out:
 		path_put(&nd->root);
 	if (base)
 		fput(base);
-	release_open_intent(nd);
-	if (filp == ERR_PTR(-EOPENSTALE)) {
+	if (od.filp) {
+		BUG_ON(od.filp->f_path.dentry);
+		put_filp(od.filp);
+	}
+	if (res == ERR_PTR(-EOPENSTALE)) {
 		if (flags & LOOKUP_RCU)
-			filp = ERR_PTR(-ECHILD);
+			res = ERR_PTR(-ECHILD);
 		else
-			filp = ERR_PTR(-ESTALE);
+			res = ERR_PTR(-ESTALE);
 	}
-	return filp;
+	return res;
 
 out_filp:
-	filp = ERR_PTR(error);
+	res = ERR_PTR(error);
 	goto out;
 }
 
@@ -2809,7 +2805,6 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path
 		goto out;
 	nd.flags &= ~LOOKUP_PARENT;
 	nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL;
-	nd.intent.open.flags = O_EXCL;
 
 	/*
 	 * Do the final lookup.
diff --git a/fs/open.c b/fs/open.c
index a973c2c..7b9b931 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -761,46 +761,6 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 }
 
 /**
- * lookup_instantiate_filp - instantiates the open intent filp
- * @nd: pointer to nameidata
- * @dentry: pointer to dentry
- * @open: open callback
- *
- * Helper for filesystems that want to use lookup open intents and pass back
- * a fully instantiated struct file to the caller.
- * This function is meant to be called from within a filesystem's
- * lookup method.
- * Beware of calling it for non-regular files! Those ->open methods might block
- * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
- * leading to a deadlock, as nobody can open that fifo anymore, because
- * another process to open fifo will block on locked parent when doing lookup).
- * Note that in case of error, nd->intent.open.file is destroyed, but the
- * path information remains valid.
- * If the open callback is set to NULL, then the standard f_op->open()
- * filesystem callback is substituted.
- */
-struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
-		int (*open)(struct inode *, struct file *))
-{
-	const struct cred *cred = current_cred();
-
-	if (IS_ERR(nd->intent.open.file))
-		goto out;
-	if (IS_ERR(dentry))
-		goto out_err;
-	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
-					     nd->intent.open.file,
-					     open, cred);
-out:
-	return nd->intent.open.file;
-out_err:
-	release_open_intent(nd);
-	nd->intent.open.file = ERR_CAST(dentry);
-	goto out;
-}
-EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
-
-/**
  * finish_open - finish opening a file
  * @od: opaque open data
  * @dentry: pointer to dentry
@@ -819,9 +779,9 @@ struct file *finish_open(struct opendata *od, struct dentry *dentry,
 	mntget(od->mnt);
 	dget(dentry);
 
-	res = do_dentry_open(dentry, od->mnt, *od->filp, open, current_cred());
+	res = do_dentry_open(dentry, od->mnt, od->filp, open, current_cred());
 	if (!IS_ERR(res))
-		*od->filp = NULL;
+		od->filp = NULL;
 
 	return res;
 }
@@ -842,49 +802,6 @@ void finish_no_open(struct opendata *od, struct dentry *dentry)
 }
 EXPORT_SYMBOL(finish_no_open);
 
-/**
- * nameidata_to_filp - convert a nameidata to an open filp.
- * @nd: pointer to nameidata
- * @flags: open flags
- *
- * Note that this function destroys the original nameidata
- */
-struct file *nameidata_to_filp(struct nameidata *nd)
-{
-	const struct cred *cred = current_cred();
-	struct file *filp;
-
-	/* Pick up the filp from the open intent */
-	filp = nd->intent.open.file;
-
-	/* Has the filesystem initialised the file for us? */
-	if (filp->f_path.dentry != NULL) {
-		nd->intent.open.file = NULL;
-	} else {
-		struct file *res;
-
-		path_get(&nd->path);
-		res = do_dentry_open(nd->path.dentry, nd->path.mnt,
-				     filp, NULL, cred);
-		if (!IS_ERR(res)) {
-			int error;
-
-			nd->intent.open.file = NULL;
-			BUG_ON(res != filp);
-
-			error = open_check_o_direct(filp);
-			if (error) {
-				fput(filp);
-				filp = ERR_PTR(error);
-			}
-		} else {
-			/* Allow nd->intent.open.file to be recycled */
-			filp = res;
-		}
-	}
-	return filp;
-}
-
 /*
  * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
  * error.
diff --git a/include/linux/namei.h b/include/linux/namei.h
index ffc0213..54dadda 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -7,12 +7,6 @@
 
 struct vfsmount;
 
-struct open_intent {
-	int	flags;
-	int	create_mode;
-	struct file *file;
-};
-
 enum { MAX_NESTED_LINKS = 8 };
 
 struct nameidata {
@@ -25,11 +19,6 @@ struct nameidata {
 	int		last_type;
 	unsigned	depth;
 	char *saved_names[MAX_NESTED_LINKS + 1];
-
-	/* Intent data */
-	union {
-		struct open_intent open;
-	} intent;
 };
 
 /*
-- 
1.7.7

[PATCH 33/34] vfs: do_last(): clean up error handling

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   23 ++++++++---------------
 1 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index b6020ca..ed0b72b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2654,21 +2654,14 @@ common:
 	if (error)
 		goto exit_fput;
 opened:
-	if (!IS_ERR(filp)) {
-		error = ima_file_check(filp, op->acc_mode);
-		if (error) {
-			fput(filp);
-			filp = ERR_PTR(error);
-		}
-	}
-	if (!IS_ERR(filp)) {
-		if (will_truncate) {
-			error = handle_truncate(filp);
-			if (error) {
-				fput(filp);
-				filp = ERR_PTR(error);
-			}
-		}
+	error = ima_file_check(filp, op->acc_mode);
+	if (error)
+		goto exit_fput;
+
+	if (will_truncate) {
+		error = handle_truncate(filp);
+		if (error)
+			goto exit_fput;
 	}
 out:
 	if (want_write)
-- 
1.7.7

[PATCH 34/34] vfs: move O_DIRECT check to common code

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@suse.cz>

Perform open_check_o_direct() in a common place in do_last after opening the
file.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c |   17 +++++------------
 1 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index ed0b72b..07fae42 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2327,22 +2327,15 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 	 * here.
 	 */
 	error = may_open(&filp->f_path, acc_mode, open_flag);
-	if (error)
-		goto out_fput;
-
-	error = open_check_o_direct(filp);
-	if (error)
-		goto out_fput;
+	if (error) {
+		fput(filp);
+		filp = ERR_PTR(error);
+	}
 
 out:
 	dput(dentry);
 	return filp;
 
-out_fput:
-	fput(filp);
-	filp = ERR_PTR(error);
-	goto out;
-
 no_open:
 	if (need_lookup) {
 		dentry = lookup_real(dir, dentry, nd);
@@ -2650,10 +2643,10 @@ common:
 	}
 	if (IS_ERR(filp))
 		goto out;
+opened:
 	error = open_check_o_direct(filp);
 	if (error)
 		goto exit_fput;
-opened:
 	error = ima_file_check(filp, op->acc_mode);
 	if (error)
 		goto exit_fput;
-- 
1.7.7