NFS: Switch to using mapping->private_lock for page writeback lookups.

Switch from using the inode->i_lock for this to avoid contention with
other metadata manipulation.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2017-08-01 12:34:44 -04:00
parent 5cb953d4b1
commit 4b9bb25b36

View File

@ -172,18 +172,18 @@ nfs_page_private_request(struct page *page)
static struct nfs_page *
nfs_page_find_private_request(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
struct address_space *mapping = page_file_mapping(page);
struct nfs_page *req;
if (!PagePrivate(page))
return NULL;
spin_lock(&inode->i_lock);
spin_lock(&mapping->private_lock);
req = nfs_page_private_request(page);
if (req) {
WARN_ON_ONCE(req->wb_head != req);
kref_get(&req->wb_kref);
}
spin_unlock(&inode->i_lock);
spin_unlock(&mapping->private_lock);
return req;
}
@ -743,6 +743,7 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
*/
static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
{
struct address_space *mapping = page_file_mapping(req->wb_page);
struct nfs_inode *nfsi = NFS_I(inode);
WARN_ON_ONCE(req->wb_this_page != req);
@ -750,19 +751,23 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
/* Lock the request! */
nfs_lock_request(req);
spin_lock(&inode->i_lock);
if (!nfs_have_writebacks(inode) &&
NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
inode->i_version++;
/*
* Swap-space should not get truncated. Hence no need to plug the race
* with invalidate/truncate.
*/
spin_lock(&mapping->private_lock);
if (!nfs_have_writebacks(inode) &&
NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) {
spin_lock(&inode->i_lock);
inode->i_version++;
spin_unlock(&inode->i_lock);
}
if (likely(!PageSwapCache(req->wb_page))) {
set_bit(PG_MAPPED, &req->wb_flags);
SetPagePrivate(req->wb_page);
set_page_private(req->wb_page, (unsigned long)req);
}
spin_unlock(&mapping->private_lock);
atomic_long_inc(&nfsi->nrequests);
/* this a head request for a page group - mark it as having an
* extra reference so sub groups can follow suit.
@ -770,7 +775,6 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
* adding subrequests. */
WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
kref_get(&req->wb_kref);
spin_unlock(&inode->i_lock);
}
/*
@ -778,7 +782,8 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
*/
static void nfs_inode_remove_request(struct nfs_page *req)
{
struct inode *inode = d_inode(req->wb_context->dentry);
struct address_space *mapping = page_file_mapping(req->wb_page);
struct inode *inode = mapping->host;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_page *head;
@ -786,13 +791,13 @@ static void nfs_inode_remove_request(struct nfs_page *req)
if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
head = req->wb_head;
spin_lock(&inode->i_lock);
spin_lock(&mapping->private_lock);
if (likely(head->wb_page && !PageSwapCache(head->wb_page))) {
set_page_private(head->wb_page, 0);
ClearPagePrivate(head->wb_page);
clear_bit(PG_MAPPED, &head->wb_flags);
}
spin_unlock(&inode->i_lock);
spin_unlock(&mapping->private_lock);
}
if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags))