Commit 612c9384 authored by Trond Myklebust's avatar Trond Myklebust Committed by Linus Torvalds

NFS: Fix the 'desynchronized value of nfs_i.ncommit' error

Redirtying a request that is already marked for commit will screw up the
accounting for NR_UNSTABLE_NFS as well as nfs_i.ncommit.
Ensure that all requests on the commit queue are labelled with the
PG_NEED_COMMIT flag, and avoid moving them onto the dirty list inside
nfs_page_mark_flush().

Also inline nfs_mark_request_dirty() into nfs_page_mark_flush() for
atomicity reasons. Avoid dropping the spinlock until we're done marking the
request in the radix tree and have added it to the ->dirty list.
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6d677e35
......@@ -38,7 +38,6 @@
static struct nfs_page * nfs_update_request(struct nfs_open_context*,
struct page *,
unsigned int, unsigned int);
static void nfs_mark_request_dirty(struct nfs_page *req);
static long nfs_flush_mapping(struct address_space *mapping, struct writeback_control *wbc, int how);
static const struct rpc_call_ops nfs_write_partial_ops;
static const struct rpc_call_ops nfs_write_full_ops;
......@@ -255,7 +254,8 @@ static void nfs_end_page_writeback(struct page *page)
static int nfs_page_mark_flush(struct page *page)
{
struct nfs_page *req;
spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
struct nfs_inode *nfsi = NFS_I(page->mapping->host);
spinlock_t *req_lock = &nfsi->req_lock;
int ret;
spin_lock(req_lock);
......@@ -279,11 +279,23 @@ static int nfs_page_mark_flush(struct page *page)
return ret;
spin_lock(req_lock);
}
if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {
/* This request is marked for commit */
spin_unlock(req_lock);
nfs_unlock_request(req);
return 1;
}
if (nfs_set_page_writeback(page) == 0) {
nfs_list_remove_request(req);
nfs_mark_request_dirty(req);
}
/* add the request to the inode's dirty list. */
radix_tree_tag_set(&nfsi->nfs_page_tree,
req->wb_index, NFS_PAGE_TAG_DIRTY);
nfs_list_add_request(req, &nfsi->dirty);
nfsi->ndirty++;
spin_unlock(req_lock);
__mark_inode_dirty(page->mapping->host, I_DIRTY_PAGES);
} else
spin_unlock(req_lock);
ret = test_bit(PG_NEED_FLUSH, &req->wb_flags);
nfs_unlock_request(req);
return ret;
......@@ -406,24 +418,6 @@ static void nfs_inode_remove_request(struct nfs_page *req)
nfs_release_request(req);
}
/*
* Add a request to the inode's dirty list.
*/
static void
nfs_mark_request_dirty(struct nfs_page *req)
{
struct inode *inode = req->wb_context->dentry->d_inode;
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&nfsi->req_lock);
radix_tree_tag_set(&nfsi->nfs_page_tree,
req->wb_index, NFS_PAGE_TAG_DIRTY);
nfs_list_add_request(req, &nfsi->dirty);
nfsi->ndirty++;
spin_unlock(&nfsi->req_lock);
__mark_inode_dirty(inode, I_DIRTY_PAGES);
}
static void
nfs_redirty_request(struct nfs_page *req)
{
......@@ -438,7 +432,7 @@ nfs_dirty_request(struct nfs_page *req)
{
struct page *page = req->wb_page;
if (page == NULL)
if (page == NULL || test_bit(PG_NEED_COMMIT, &req->wb_flags))
return 0;
return !PageWriteback(req->wb_page);
}
......@@ -456,6 +450,7 @@ nfs_mark_request_commit(struct nfs_page *req)
spin_lock(&nfsi->req_lock);
nfs_list_add_request(req, &nfsi->commit);
nfsi->ncommit++;
set_bit(PG_NEED_COMMIT, &(req)->wb_flags);
spin_unlock(&nfsi->req_lock);
inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
......@@ -470,7 +465,7 @@ int nfs_write_need_commit(struct nfs_write_data *data)
static inline
int nfs_reschedule_unstable_write(struct nfs_page *req)
{
if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) {
if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {
nfs_mark_request_commit(req);
return 1;
}
......@@ -557,6 +552,7 @@ static void nfs_cancel_commit_list(struct list_head *head)
req = nfs_list_entry(head->next);
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
nfs_list_remove_request(req);
clear_bit(PG_NEED_COMMIT, &(req)->wb_flags);
nfs_inode_remove_request(req);
nfs_unlock_request(req);
}
......@@ -1295,6 +1291,7 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)
while (!list_empty(&data->pages)) {
req = nfs_list_entry(data->pages.next);
nfs_list_remove_request(req);
clear_bit(PG_NEED_COMMIT, &(req)->wb_flags);
dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
dprintk("NFS: commit (%s/%Ld %d@%Ld)",
......
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