NFS: Add attribute update barriers to NFS writebacks

Ensure that other operations that race with our write RPC calls
cannot revert the file size updates that were made on the server.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Trond Myklebust
2015-02-26 17:36:09 -05:00
parent f506200346
commit a08a8cd375
7 changed files with 57 additions and 8 deletions

View File

@@ -1377,6 +1377,36 @@ static int nfs_should_remove_suid(const struct inode *inode)
return 0;
}
static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
struct nfs_fattr *fattr)
{
struct nfs_pgio_args *argp = &hdr->args;
struct nfs_pgio_res *resp = &hdr->res;
if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
return;
if (argp->offset + resp->count != fattr->size)
return;
if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode))
return;
/* Set attribute barrier */
nfs_fattr_set_barrier(fattr);
}
void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
{
struct nfs_fattr *fattr = hdr->res.fattr;
struct inode *inode = hdr->inode;
if (fattr == NULL)
return;
spin_lock(&inode->i_lock);
nfs_writeback_check_extend(hdr, fattr);
nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);
/*
* This function is called when the WRITE call is complete.
*/