NFS: Fix cache consistency races
If the data cache has been marked as potentially invalid by nfs_refresh_inode,
we should invalidate it rather than assume that changes are due to our own
activity.
Also ensure that we always start with a valid cache before declaring it
to be protected by a delegation.
Signed-off-by: Trond Myklebust <[email protected]>
---
delegation.c | 4 ++++
file.c | 3 ++-
inode.c | 7 ++-----
3 files changed, 8 insertions(+), 6 deletions(-)
Index: linux-2.6.14-rc4/fs/nfs/delegation.c
===================================================================
--- linux-2.6.14-rc4.orig/fs/nfs/delegation.c
+++ linux-2.6.14-rc4/fs/nfs/delegation.c
@@ -85,6 +85,10 @@ int nfs_inode_set_delegation(struct inod
struct nfs_delegation *delegation;
int status = 0;
+ /* Ensure we first revalidate the attributes and page cache! */
+ if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
+ __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+
delegation = nfs_alloc_delegation();
if (delegation == NULL)
return -ENOMEM;
Index: linux-2.6.14-rc4/fs/nfs/file.c
===================================================================
--- linux-2.6.14-rc4.orig/fs/nfs/file.c
+++ linux-2.6.14-rc4/fs/nfs/file.c
@@ -137,7 +137,8 @@ static int nfs_revalidate_file(struct in
struct nfs_inode *nfsi = NFS_I(inode);
int retval = 0;
- if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) || nfs_attribute_timeout(inode))
+ if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR))
+ || nfs_attribute_timeout(inode))
retval = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
nfs_revalidate_mapping(inode, filp->f_mapping);
return 0;
Index: linux-2.6.14-rc4/fs/nfs/inode.c
===================================================================
--- linux-2.6.14-rc4.orig/fs/nfs/inode.c
+++ linux-2.6.14-rc4/fs/nfs/inode.c
@@ -1226,10 +1226,6 @@ int nfs_refresh_inode(struct inode *inod
loff_t cur_size, new_isize;
int data_unstable;
- /* Do we hold a delegation? */
- if (nfs_have_delegation(inode, FMODE_READ))
- return 0;
-
spin_lock(&inode->i_lock);
/* Are we in the process of updating data on the server? */
@@ -1350,7 +1346,8 @@ static int nfs_update_inode(struct inode
nfsi->read_cache_jiffies = fattr->timestamp;
/* Are we racing with known updates of the metadata on the server? */
- data_unstable = ! nfs_verify_change_attribute(inode, verifier);
+ data_unstable = ! (nfs_verify_change_attribute(inode, verifier) ||
+ (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE));
/* Check if our cached file size is stale */
new_isize = nfs_size_to_loff_t(fattr->size);
Trond Myklebust <[email protected]> writes:
> Does the attached patch help?
Yes, it does indeed seem to solve the problem.
Thanks!
--
Leif Nixon - Systems expert
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National Supercomputer Centre - Linkoping University
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