[PATCH] knfsd: nfsd4: fix acl xattr length return

We should be using the length from the second vfs_getxattr, in case it
changed.  (Note: there's still a small race here; we could end up returning
-ENOMEM if the length increased between the first and second call.  I don't
know whether it's worth spending a lot of effort to fix that.)

This makes XFS ACLs usable on NFS exports, which they currently aren't, since
XFS appears to be returning a too-large value for vfs_getxattr() when it's
passed a NULL buffer.  So there's probably an XFS bug here too, though since
getxattr with a NULL buffer is usually used to decide how much memory to
allocate, it may be a fairly harmless bug in most cases.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 31018333dc383f58905f6348ac7a949de04849ca..6aa92d0e68764a7b4ef0ab7de0f34003570f71f8 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -371,7 +371,6 @@ out_nfserr:
 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
 {
        ssize_t buflen;
-       int error;
 
        buflen = vfs_getxattr(dentry, key, NULL, 0);
        if (buflen <= 0)
@@ -381,10 +380,7 @@ static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
        if (!*buf)
                return -ENOMEM;
 
-       error = vfs_getxattr(dentry, key, *buf, buflen);
-       if (error < 0)
-               return error;
-       return buflen;
+       return vfs_getxattr(dentry, key, *buf, buflen);
 }
 #endif