It's great when we can shave an extra RPC, but not at the expense of correctness. We should not return EPERM (from vfs_create/mknod/mkdir) if the name already exists, even if we have no write access in parent. Since the check in nfs_permission is clearly not enough to stave off this, just throw in the extra READ access to actually go through. Signed-off-by: Oleg Drokin <green@xxxxxxxxxxxxxx> --- fs/nfs/dir.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index d8015a0..8c7835b 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1383,8 +1383,10 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in /* * If we're doing an exclusive create, optimize away the lookup * but don't hash the dentry. + * This optimization only works if we can write in the parent. */ - if (nfs_is_exclusive_create(dir, flags)) + if (nfs_is_exclusive_create(dir, flags) && + (inode_permission(dir, MAY_WRITE | MAY_READ | MAY_EXEC) == 0)) return NULL; res = ERR_PTR(-ENOMEM); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
