[PATCH 47/53] VFS: make d_alloc() local to VFS.

[NeilBrown]

From: NeilBrown <neil at brown.name>

d_alloc() is not useful.  d_alloc_name() is a better interface for
those cases where it is safe to allocate a dentry without
synchronisation with the VFS, and d_alloc_parallel() or
d_alloc_noblock() shoudl be used when synchronisation is needed.

Signed-off-by: NeilBrown <neil at brown.name>
---
 Documentation/filesystems/porting.rst | 8 ++++++++
 fs/dcache.c                           | 1 -
 fs/internal.h                         | 1 +
 include/linux/dcache.h                | 1 -
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 6a507c508ccf..4712403fd98e 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1381,3 +1381,11 @@ longer available.  Use start_renaming() or similar.
 
 d_alloc_parallel() no longer requires a waitqueue_head.  It uses one
 from an internal table when needed.
+
+---
+
+**mandatory**
+
+d_alloc() is no longer exported as its use can be racy.  Use d_alloc_name()
+when object creation is controlled separately from standard filesystem interface,
+and d_alloc_parallel() or d_alloc_noblock() when standard interfaces can be used.
diff --git a/fs/dcache.c b/fs/dcache.c
index 9a6139013367..23f04fa05778 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1830,7 +1830,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 
 	return dentry;
 }
-EXPORT_SYMBOL(d_alloc);
 
 /**
  * d_duplicate: duplicate a dentry for combined atomic operation
diff --git a/fs/internal.h b/fs/internal.h
index cbc384a1aa09..9c637e2d18ef 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -223,6 +223,7 @@ bool sync_lazytime(struct inode *inode);
 /*
  * dcache.c
  */
+struct dentry *d_alloc(struct dentry * parent, const struct qstr *name);
 extern int d_set_mounted(struct dentry *dentry);
 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
 extern struct dentry *d_alloc_cursor(struct dentry *);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 3b12577ddfbb..18242f9598dc 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -242,7 +242,6 @@ extern void d_drop(struct dentry *dentry);
 extern void d_delete(struct dentry *);
 
 /* allocate/de-allocate */
-extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
 extern struct dentry * d_alloc_anon(struct super_block *);
 extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *);
 extern struct dentry * d_alloc_noblock(struct dentry *, struct qstr *);
-- 
2.50.0.107.gf914562f5916.dirty