make lookup_create non-static

Make lookup_create non-static for use by certain pseudofilesystems (e.g. hwgfs).

Quoted 3 lines · [email protected] (Jesse Barnes) wrote:

Make lookup_create non-static for use by certain pseudofilesystems (e.g. hwgfs).

If one is patching ones kernel with hwgfs, once can include this chunk in that patch, no?

You mean copy lookup_create into hwgfs (which is already in the tree,
btw)? Yeah, I guess I could do that if you don't want to take this.

Quoted 3 lines · [email protected] (Jesse Barnes) wrote:

You mean copy lookup_create into hwgfs (which is already in the tree,
btw)? Yeah, I guess I could do that if you don't want to take this.

ah, I thought you were referring to an out-of-tree filesystem.

It would appear that intermezzo has already created a private copy of lookup_create(). Sigh.

If we're going to export this thing to filesystems then it really should be documented a bit. You could bribe me with a patch which does that ;)

Ok, how does this look?

Quoted 2 lines · [email protected] (Jesse Barnes) wrote:

Ok, how does this look?

OK. I grew it a bit:

 fs/intermezzo/vfs.c    |   22 ----------------------
 fs/namei.c             |   11 +++++++++--
 include/linux/dcache.h |    2 ++
 include/linux/fs.h     |    0 
 kernel/ksyms.c         |    1 +
 5 files changed, 12 insertions(+), 24 deletions(-)

diff -puN fs/namei.c~export-lookup_create fs/namei.c

fs/namei.c renamed from fs/namei.c~export-lookup_create +9 -2

@@ -1375,8 +1375,15 @@ do_link:
 	goto do_last;
 }
 
-/* SMP-safe */
-static struct dentry *lookup_create(struct nameidata *nd, int is_dir)
+/**
+ * lookup_create - lookup a dentry, creating it if it doesn't exist
+ * @nd: nameidata info
+ * @is_dir: directory flag
+ *
+ * Simple function to lookup and return a dentry and create it
+ * if it doesn't exist.  Is SMP-safe.
+ */
+struct dentry *lookup_create(struct nameidata *nd, int is_dir)
 {
 	struct dentry *dentry;
 

diff -puN include/linux/fs.h~export-lookup_create include/linux/fs.h diff -puN include/linux/dcache.h~export-lookup_create include/linux/dcache.h

include/linux/dcache.h renamed from include/linux/dcache.h~export-lookup_create +2 -0

@@ -309,6 +309,8 @@ static inline int d_mountpoint(struct de
 }
 
 extern struct vfsmount *lookup_mnt(struct vfsmount *, struct dentry *);
+extern struct dentry *lookup_create(struct nameidata *nd, int is_dir);
+
 #endif /* __KERNEL__ */
 
 #endif	/* __LINUX_DCACHE_H */

diff -puN kernel/ksyms.c~export-lookup_create kernel/ksyms.c

kernel/ksyms.c renamed from kernel/ksyms.c~export-lookup_create +1 -0

@@ -156,6 +156,7 @@ EXPORT_SYMBOL(inode_init_once);
 EXPORT_SYMBOL(follow_up);
 EXPORT_SYMBOL(follow_down);
 EXPORT_SYMBOL(lookup_mnt);
+EXPORT_SYMBOL(lookup_create);
 EXPORT_SYMBOL(path_lookup);
 EXPORT_SYMBOL(path_walk);
 EXPORT_SYMBOL(path_release);

diff -puN fs/intermezzo/vfs.c~export-lookup_create fs/intermezzo/vfs.c

fs/intermezzo/vfs.c renamed from fs/intermezzo/vfs.c~export-lookup_create +0 -22

@@ -664,28 +664,6 @@ int presto_do_create(struct presto_file_
         return error;
 }
 
-/* from namei.c */
-static struct dentry *lookup_create(struct nameidata *nd, int is_dir)
-{
-        struct dentry *dentry;
-
-        down(&nd->dentry->d_inode->i_sem);
-        dentry = ERR_PTR(-EEXIST);
-        if (nd->last_type != LAST_NORM)
-                goto fail;
-        dentry = lookup_hash(&nd->last, nd->dentry);
-        if (IS_ERR(dentry))
-                goto fail;
-        if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
-                goto enoent;
-        return dentry;
-enoent:
-        dput(dentry);
-        dentry = ERR_PTR(-ENOENT);
-fail:
-        return dentry;
-}
-
 int lento_create(const char *name, int mode, struct lento_vfs_context *info)
 {
         int error;

_