Commit f01bfc97 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs 

Pull NFS client fixes from Trond Myklebust:
 "Highlights:

   - more fixes for read/write codepath regressions
     * sleeping while holding the inode lock
     * stricter enforcement of page contiguity when coalescing requests
     * fix up error handling in the page coalescing code

   - don't busy wait on SIGKILL in the file locking code"

* tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: Don't busy-wait on SIGKILL in __nfs_iocounter_wait
  nfs: can_coalesce_requests must enforce contiguity
  nfs: disallow duplicate pages in pgio page vectors
  nfs: don't sleep with inode lock in lock_and_join_requests
  nfs: fix error handling in lock_and_join_requests
  nfs: use blocking page_group_lock in add_request
  nfs: fix nonblocking calls to nfs_page_group_lock
  nfs: change nfs_page_group_lock argument
parents dd5957b7 92a56555

fs/nfs/pagelist.c

+59 −25
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ __nfs_iocounter_wait(struct nfs_io_counter *c) 
		if (atomic_read(&c->io_count) == 0)

			break;

		ret = nfs_wait_bit_killable(&q.key);

	} while (atomic_read(&c->io_count) != 0);

	} while (atomic_read(&c->io_count) != 0 && !ret);

	finish_wait(wq, &q.wait);

	return ret;

}
@@ -139,26 +139,49 @@ nfs_iocounter_wait(struct nfs_io_counter *c) 
/*

 * nfs_page_group_lock - lock the head of the page group

 * @req - request in group that is to be locked

 * @nonblock - if true don't block waiting for lock

 *

 * this lock must be held if modifying the page group list

 *

 * returns result from wait_on_bit_lock: 0 on success, < 0 on error

 * return 0 on success, < 0 on error: -EDELAY if nonblocking or the

 * result from wait_on_bit_lock

 *

 * NOTE: calling with nonblock=false should always have set the

 *       lock bit (see fs/buffer.c and other uses of wait_on_bit_lock

 *       with TASK_UNINTERRUPTIBLE), so there is no need to check the result.

 */

int

nfs_page_group_lock(struct nfs_page *req, bool wait)

nfs_page_group_lock(struct nfs_page *req, bool nonblock)

{

	struct nfs_page *head = req->wb_head;

	int ret;



	WARN_ON_ONCE(head != head->wb_head);



	do {

		ret = wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,

	if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))

		return 0;



	if (!nonblock)

		return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,

				TASK_UNINTERRUPTIBLE);

	} while (wait && ret != 0);



	WARN_ON_ONCE(ret > 0);

	return ret;

	return -EAGAIN;

}



/*

 * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it

 * @req - a request in the group

 *

 * This is a blocking call to wait for the group lock to be cleared.

 */

void

nfs_page_group_lock_wait(struct nfs_page *req)

{

	struct nfs_page *head = req->wb_head;



	WARN_ON_ONCE(head != head->wb_head);



	wait_on_bit(&head->wb_flags, PG_HEADLOCK,

		TASK_UNINTERRUPTIBLE);

}



/*
@@ -219,7 +242,7 @@ bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) 
{

	bool ret;



	nfs_page_group_lock(req, true);

	nfs_page_group_lock(req, false);

	ret = nfs_page_group_sync_on_bit_locked(req, bit);

	nfs_page_group_unlock(req);
@@ -701,10 +724,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, 
		     struct nfs_pgio_header *hdr)

{

	struct nfs_page		*req;

	struct page		**pages;

	struct page		**pages,

				*last_page;

	struct list_head *head = &desc->pg_list;

	struct nfs_commit_info cinfo;

	unsigned int pagecount;

	unsigned int pagecount, pageused;



	pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count);

	if (!nfs_pgarray_set(&hdr->page_array, pagecount))
@@ -712,12 +736,23 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, 


	nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);

	pages = hdr->page_array.pagevec;

	last_page = NULL;

	pageused = 0;

	while (!list_empty(head)) {

		req = nfs_list_entry(head->next);

		nfs_list_remove_request(req);

		nfs_list_add_request(req, &hdr->pages);

		*pages++ = req->wb_page;



		if (WARN_ON_ONCE(pageused >= pagecount))

			return nfs_pgio_error(desc, hdr);



		if (!last_page || last_page != req->wb_page) {

			*pages++ = last_page = req->wb_page;

			pageused++;

		}

	}

	if (WARN_ON_ONCE(pageused != pagecount))

		return nfs_pgio_error(desc, hdr);



	if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&

	    (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
@@ -788,6 +823,14 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev, 
			return false;

		if (req_offset(req) != req_offset(prev) + prev->wb_bytes)

			return false;

		if (req->wb_page == prev->wb_page) {

			if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)

				return false;

		} else {

			if (req->wb_pgbase != 0 ||

			    prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)

				return false;

		}

	}

	size = pgio->pg_ops->pg_test(pgio, prev, req);

	WARN_ON_ONCE(size > req->wb_bytes);
@@ -858,13 +901,8 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 
	struct nfs_page *subreq;

	unsigned int bytes_left = 0;

	unsigned int offset, pgbase;

	int ret;



	ret = nfs_page_group_lock(req, false);

	if (ret < 0) {

		desc->pg_error = ret;

		return 0;

	}

	nfs_page_group_lock(req, false);



	subreq = req;

	bytes_left = subreq->wb_bytes;
@@ -886,11 +924,7 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 
			if (desc->pg_recoalesce)

				return 0;

			/* retry add_request for this subreq */

			ret = nfs_page_group_lock(req, false);

			if (ret < 0) {

				desc->pg_error = ret;

				return 0;

			}

			nfs_page_group_lock(req, false);

			continue;

		}

fs/nfs/write.c

+17 −4
Original line number Diff line number Diff line
@@ -241,7 +241,7 @@ static bool nfs_page_group_covers_page(struct nfs_page *req) 
	unsigned int pos = 0;

	unsigned int len = nfs_page_length(req->wb_page);



	nfs_page_group_lock(req, true);

	nfs_page_group_lock(req, false);



	do {

		tmp = nfs_page_group_search_locked(req->wb_head, pos);
@@ -478,10 +478,23 @@ try_again: 
		return NULL;

	}



	/* lock each request in the page group */

	ret = nfs_page_group_lock(head, false);

	if (ret < 0)

	/* holding inode lock, so always make a non-blocking call to try the

	 * page group lock */

	ret = nfs_page_group_lock(head, true);

	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_release_request(head);

		return ERR_PTR(ret);

	}



	/* lock each request in the page group */

	subreq = head;

	do {

		/*

include/linux/nfs_page.h

+1 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ extern int nfs_wait_on_request(struct nfs_page *); 
extern	void nfs_unlock_request(struct nfs_page *req);

extern	void nfs_unlock_and_release_request(struct nfs_page *);

extern int nfs_page_group_lock(struct nfs_page *, bool);

extern void nfs_page_group_lock_wait(struct nfs_page *);

extern void nfs_page_group_unlock(struct nfs_page *);

extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);

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