We forgot to unregister the nfs4_xattr_large_entry_shrinker.
That leaves the global list of shrinkers corrupted after unload of the
nfs module, after which possibly unrelated code that calls
register_shrinker() or unregister_shrinker() gets a BUG() with
"supervisor write access in kernel mode".
And similarly for the nfs4_xattr_large_entry_lru.
Reported-by: Kris Karas <bugs-a17@moonlit-rail.com>
Tested-By: Kris Karas <bugs-a17@moonlit-rail.com>
Fixes: 95ad37f90c "NFSv4.2: add client side xattr caching."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The list_lru_count() returns the pre node count, but the new xattr
shrinkers are memcg aware, so the shrinkers should return per memcg
count by calling list_lru_shrink_count() instead. Otherwise over-shrink
might be experienced. The problem was spotted by visual code
inspection.
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The hash_lock field of the cache structure was a leftover
of a previous iteration of the code. It is now unused,
so remove it.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Caches should be small enough to discard them inline, so do that
instead of using a work queue.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Implement client side caching for NFSv4.2 extended attributes. The cache
is a per-inode hashtable, with name/value entries. There is one special
entry for the listxattr cache.
NFS inodes have a pointer to a cache structure. The cache structure is
allocated on demand, freed when the cache is invalidated.
Memory shrinkers keep the size in check. Large entries (> PAGE_SIZE)
are collected by a separate shrinker, and freed more aggressively
than others.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Bhaskar Chowdhury