NFS: Teach nfs_try_to_update_request() to deal with request page_groups

Simplify the code, and avoid some flushes to disk.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2017-07-17 19:50:23 -04:00
parent b66aaa8dfe
commit f6032f216f

View file

@ -1107,39 +1107,19 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
end = offset + bytes;
for (;;) {
if (!(PagePrivate(page) || PageSwapCache(page)))
return NULL;
spin_lock(&inode->i_lock);
req = nfs_page_find_head_request_locked(NFS_I(inode), page);
if (req == NULL)
goto out_unlock;
req = nfs_lock_and_join_requests(page);
if (IS_ERR_OR_NULL(req))
return req;
/* should be handled by nfs_flush_incompatible */
WARN_ON_ONCE(req->wb_head != req);
WARN_ON_ONCE(req->wb_this_page != req);
rqend = req->wb_offset + req->wb_bytes;
/*
* Tell the caller to flush out the request if
* the offsets are non-contiguous.
* Note: nfs_flush_incompatible() will already
* have flushed out requests having wrong owners.
*/
if (offset > rqend
|| end < req->wb_offset)
goto out_flushme;
if (nfs_lock_request(req))
break;
/* The request is locked, so wait and then retry */
spin_unlock(&inode->i_lock);
error = nfs_wait_on_request(req);
nfs_release_request(req);
if (error != 0)
goto out_err;
}
rqend = req->wb_offset + req->wb_bytes;
/*
* Tell the caller to flush out the request if
* the offsets are non-contiguous.
* Note: nfs_flush_incompatible() will already
* have flushed out requests having wrong owners.
*/
if (offset > rqend || end < req->wb_offset)
goto out_flushme;
/* Okay, the request matches. Update the region */
if (offset < req->wb_offset) {
@ -1150,17 +1130,17 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
req->wb_bytes = end - req->wb_offset;
else
req->wb_bytes = rqend - req->wb_offset;
out_unlock:
if (req)
nfs_clear_request_commit(req);
spin_unlock(&inode->i_lock);
return req;
out_flushme:
spin_unlock(&inode->i_lock);
nfs_release_request(req);
/*
* Note: we mark the request dirty here because
* nfs_lock_and_join_requests() cannot preserve
* commit flags, so we have to replay the write.
*/
nfs_mark_request_dirty(req);
nfs_unlock_and_release_request(req);
error = nfs_wb_page(inode, page);
out_err:
return ERR_PTR(error);
return (error < 0) ? ERR_PTR(error) : NULL;
}
/*