We don't expect the page header lock to ever be held across I/O, so
it should always be safe to wait for it, even if we're doing nonblocking
writebacks.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/write.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index b1af5dee5e0a..1d447e37f472 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -366,7 +366,6 @@ nfs_page_group_clear_bits(struct nfs_page *req)
* @inode - inode associated with request page group, must be holding inode lock
* @head - head request of page group, must be holding head lock
* @req - request that couldn't lock and needs to wait on the req bit lock
- * @nonblock - if true, don't actually wait
*
* NOTE: this must be called holding page_group bit lock and inode spin lock
* and BOTH will be released before returning.
@@ -375,7 +374,7 @@ nfs_page_group_clear_bits(struct nfs_page *req)
*/
static int
nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
- struct nfs_page *req, bool nonblock)
+ struct nfs_page *req)
__releases(&inode->i_lock)
{
struct nfs_page *tmp;
@@ -396,10 +395,7 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
/* release ref from nfs_page_find_head_request_locked */
nfs_release_request(head);
- if (!nonblock)
- ret = nfs_wait_on_request(req);
- else
- ret = -EAGAIN;
+ ret = nfs_wait_on_request(req);
nfs_release_request(req);
return ret;
@@ -464,7 +460,6 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
* operations for this page.
*
* @page - the page used to lookup the "page group" of nfs_page structures
- * @nonblock - if true, don't block waiting for request locks
*
* This function joins all sub requests to the head request by first
* locking all requests in the group, cancelling any pending operations
@@ -478,7 +473,7 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
* error was encountered.
*/
static struct nfs_page *
-nfs_lock_and_join_requests(struct page *page, bool nonblock)
+nfs_lock_and_join_requests(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *head, *subreq;
@@ -511,14 +506,9 @@ nfs_lock_and_join_requests(struct page *page, bool nonblock)
if (ret < 0) {
spin_unlock(&inode->i_lock);
- if (!nonblock && ret == -EAGAIN) {
- nfs_page_group_lock_wait(head);
- nfs_release_request(head);
- goto try_again;
- }
-
+ nfs_page_group_lock_wait(head);
nfs_release_request(head);
- return ERR_PTR(ret);
+ goto try_again;
}
/* lock each request in the page group */
@@ -543,7 +533,7 @@ nfs_lock_and_join_requests(struct page *page, bool nonblock)
/* releases page group bit lock and
* inode spin lock and all references */
ret = nfs_unroll_locks_and_wait(inode, head,
- subreq, nonblock);
+ subreq);
if (ret == 0)
goto try_again;
@@ -624,12 +614,12 @@ nfs_error_is_fatal_on_server(int err)
* May return an error if the user signalled nfs_wait_on_request().
*/
static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
- struct page *page, bool nonblock)
+ struct page *page)
{
struct nfs_page *req;
int ret = 0;
- req = nfs_lock_and_join_requests(page, nonblock);
+ req = nfs_lock_and_join_requests(page);
if (!req)
goto out;
ret = PTR_ERR(req);
@@ -672,7 +662,7 @@ static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
int ret;
nfs_pageio_cond_complete(pgio, page_index(page));
- ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
+ ret = nfs_page_async_flush(pgio, page);
if (ret == -EAGAIN) {
redirty_page_for_writepage(wbc, page);
ret = 0;
@@ -2015,7 +2005,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
/* blocking call to cancel all requests and join to a single (head)
* request */
- req = nfs_lock_and_join_requests(page, false);
+ req = nfs_lock_and_join_requests(page);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
--
2.13.3
--
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