From dc59250c6ebed099a9bc0a11298e2281dd896657 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 18 Aug 2005 11:24:12 -0700 Subject: [PATCH] NFS: Introduce the use of inode->i_lock to protect fields in nfsi Down the road we want to eliminate the use of the global kernel lock entirely from the NFS client. To do this, we need to protect the fields in the nfs_inode structure adequately. Start by serializing updates to the "cache_validity" field. Note this change addresses an SMP hang found by njw@osdl.org, where processes deadlock because nfs_end_data_update and nfs_revalidate_mapping update the "cache_validity" field without proper serialization. Test plan: Millions of fsx ops on SMP clients. Run Nick Wilson's breaknfs program on large SMP clients. Signed-off-by: Chuck Lever Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/dir.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/nfs/dir.c') diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 27cf5577f239..147cbf9261ce 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -189,7 +189,9 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) goto error; } SetPageUptodate(page); + spin_lock(&inode->i_lock); NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; + spin_unlock(&inode->i_lock); /* Ensure consistent page alignment of the data. * Note: assumes we have exclusive access to this mapping either * through inode->i_sem or some other mechanism. @@ -462,7 +464,9 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, page, NFS_SERVER(inode)->dtsize, desc->plus); + spin_lock(&inode->i_lock); NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; + spin_unlock(&inode->i_lock); desc->page = page; desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ if (desc->error >= 0) { @@ -1596,7 +1600,10 @@ void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) put_rpccred(cache->cred); cache->cred = get_rpccred(set->cred); } + /* FIXME: replace current access_cache BKL reliance with inode->i_lock */ + spin_lock(&inode->i_lock); nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; + spin_unlock(&inode->i_lock); cache->jiffies = set->jiffies; cache->mask = set->mask; } -- cgit v1.2.3