We should already optimize away the unnecessary setting of the size. The problem is that truncate() still requires you to set the ctime, whereas ftruncate() does not iirc. "J. Bruce Fields" <bfields@xxxxxxxxxx> wrote: From: "J. Bruce Fields" <bfields@xxxxxxxxxx> We recently noticed that NFSv4 iozone read tests that should have been performing at local-cache speeds were running at wire speeds, and found that currently, open(O_RDWR|O_TRUNC) write() close() open(O_RDONLY) read() results in an over-the-wire read (due to a setattr triggered by O_TRUNC). Even non-O_TRUNC opens send setattrs (of timestamps) in some cases, causing the same problem. In discussion with Trond, he blames a VFS bug for breaking what should be a single open into an open followed by a setattr. However, it may make sense even in a case like open(O_RDWR) write() setattr() close() open(O_RDONLY) read() to treat the setattr similarly to the write, and not invalidate the client's own cache as long as the setattr is performed under a write open. (That said, I don't know if this is the correct place in the code to implement that behavior.) Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> --- fs/nfs/inode.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 6f4850d..d4eed06 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -438,8 +438,13 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr) if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) nfs_inode_return_delegation(inode); error = NFS_PROTO(inode)->setattr(dentry, fattr, attr); - if (error == 0) + if (error) + goto out_free; + if (attr->ia_valid & ATTR_FILE) + nfs_post_op_update_inode_force_wcc(inode, fattr); + else nfs_refresh_inode(inode, fattr); +out_free: nfs_free_fattr(fattr); out: return error; -- 1.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
