This is the second attempt to fix this problem. The first one attempted to fix this in procfs, but Eric Biederman pointed out that file bind mounts have a similar problem. This set attempts to fix the issue at a higher level, in the generic VFS layer. In certain situations, when it knows that they are valid, the path walking code will skip revalidating dentries that it finds in the cache. This causes problems with filesystems such as NFSv4 and CIFS that depend on the d_revalidate routine to do opens during lookup. A simple way to demonstrate this problem is by having a program open a file that sits on NFSv4 via a procfs symlink or file bind mount, and then try to set a fcntl read lock on the file. The lock operation will return -ENOLCK because the open file has no NFSv4 state attached. This set fixes this problem by adding a new routine to force a revalidation of the dentry in these situations when they're being done in order to open a file. This fixes my testcase, and I haven't seen any other adverse affects on it. I am however, far from certain that I'm not breaking the refcounting in the situation where open_reval_path returns an error. I'd appreciate someone giving me some sanity checks there. Also, have I missed any places that need to force a revalidate like this? Comments welcome... Jeff Layton (2): vfs: force reval of dentries for LAST_BIND symlinks on open vfs: force reval on dentry of bind mounted files for LOOKUP_OPEN fs/namei.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 48 insertions(+), 2 deletions(-) -- 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
