[PATCH 3.16 166/357] nfs: clear_request_commit while holding i_lock

From: Greg Kroah-Hartman
Date: Fri Oct 03 2014 - 20:33:38 EST


3.16-stable review patch. If anyone has any objections, please let me know.

------------------


From: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>

commit 411a99adffb4f993eee29759f744de01487044ac upstream.

Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/filelayout/filelayout.c | 5 ++---
fs/nfs/write.c | 15 ++++-----------
2 files changed, 6 insertions(+), 14 deletions(-)

--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1015,6 +1015,7 @@ static u32 select_bucket_index(struct nf

/* The generic layer is about to remove the req from the commit list.
* If this will make the bucket empty, it will need to put the lseg reference.
+ * Note this is must be called holding the inode (/cinfo) lock
*/
static void
filelayout_clear_request_commit(struct nfs_page *req,
@@ -1022,7 +1023,6 @@ filelayout_clear_request_commit(struct n
{
struct pnfs_layout_segment *freeme = NULL;

- spin_lock(cinfo->lock);
if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
goto out;
cinfo->ds->nwritten--;
@@ -1037,8 +1037,7 @@ filelayout_clear_request_commit(struct n
}
out:
nfs_request_remove_commit_list(req, cinfo);
- spin_unlock(cinfo->lock);
- pnfs_put_lseg(freeme);
+ pnfs_put_lseg_async(freeme);
}

static struct list_head *
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -379,8 +379,6 @@ nfs_destroy_unlinked_subrequests(struct
subreq->wb_head = subreq;
subreq->wb_this_page = subreq;

- nfs_clear_request_commit(subreq);
-
/* subreq is now totally disconnected from page group or any
* write / commit lists. last chance to wake any waiters */
nfs_unlock_request(subreq);
@@ -490,7 +488,7 @@ try_again:
* Commit list removal accounting is done after locks are dropped */
subreq = head;
do {
- nfs_list_remove_request(subreq);
+ nfs_clear_request_commit(subreq);
subreq = subreq->wb_this_page;
} while (subreq != head);

@@ -520,15 +518,11 @@ try_again:

nfs_page_group_unlock(head);

- /* drop lock to clear_request_commit the head req and clean up
- * requests on destroy list */
+ /* drop lock to clean uprequests on destroy list */
spin_unlock(&inode->i_lock);

nfs_destroy_unlinked_subrequests(destroy_list, head);

- /* clean up commit list state */
- nfs_clear_request_commit(head);
-
/* still holds ref on head from nfs_page_find_head_request_locked
* and still has lock on head from lock loop */
return head;
@@ -810,6 +804,7 @@ nfs_clear_page_commit(struct page *page)
dec_bdi_stat(page_file_mapping(page)->backing_dev_info, BDI_RECLAIMABLE);
}

+/* Called holding inode (/cinfo) lock */
static void
nfs_clear_request_commit(struct nfs_page *req)
{
@@ -819,9 +814,7 @@ nfs_clear_request_commit(struct nfs_page

nfs_init_cinfo_from_inode(&cinfo, inode);
if (!pnfs_clear_request_commit(req, &cinfo)) {
- spin_lock(cinfo.lock);
nfs_request_remove_commit_list(req, &cinfo);
- spin_unlock(cinfo.lock);
}
nfs_clear_page_commit(req->wb_page);
}
@@ -1040,9 +1033,9 @@ static struct nfs_page *nfs_try_to_updat
else
req->wb_bytes = rqend - req->wb_offset;
out_unlock:
- spin_unlock(&inode->i_lock);
if (req)
nfs_clear_request_commit(req);
+ spin_unlock(&inode->i_lock);
return req;
out_flushme:
spin_unlock(&inode->i_lock);


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