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Commit c663e5d8 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
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[PATCH] add some comments to lookup_create() 



In a duplicate of lookup_create in the af_unix code Al commented what's
going on nicely, so let's bring that over to lookup_create before the copy
is going away (I'll send a patch soon)

Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 70f09f1f

fs/namei.c

+18 −2
Original line number Diff line number Diff line
@@ -1577,19 +1577,35 @@ do_link: 
 *

 * Simple function to lookup and return a dentry and create it

 * if it doesn't exist.  Is SMP-safe.

 *

 * Returns with nd->dentry->d_inode->i_sem locked.

 */

struct dentry *lookup_create(struct nameidata *nd, int is_dir)

{

	struct dentry *dentry;

	struct dentry *dentry = ERR_PTR(-EEXIST);



	down(&nd->dentry->d_inode->i_sem);

	dentry = ERR_PTR(-EEXIST);

	/*

	 * Yucky last component or no last component at all?

	 * (foo/., foo/.., /////)

	 */

	if (nd->last_type != LAST_NORM)

		goto fail;

	nd->flags &= ~LOOKUP_PARENT;



	/*

	 * Do the final lookup.

	 */

	dentry = lookup_hash(&nd->last, nd->dentry);

	if (IS_ERR(dentry))

		goto fail;



	/*

	 * Special case - lookup gave negative, but... we had foo/bar/

	 * From the vfs_mknod() POV we just have a negative dentry -

	 * all is fine. Let's be bastards - you had / on the end, you've

	 * been asking for (non-existent) directory. -ENOENT for you.

	 */

	if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)

		goto enoent;

	return dentry;