aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorTrond Myklebust <Trond.Myklebust@netapp.com>2011-03-25 14:15:11 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-03-27 11:48:07 -0400
commit4d65c520fb4abed970069d18c119cfe85624f46d (patch)
tree74671eb263380317f1e4a958a6a7f73749e98eec
parent16c29dafcc86024048f1dbb8349d31cb22c7c55a (diff)
NFS: Fix a hang in the writeback path
Now that the inode scalability patches have been merged, it is no longer safe to call igrab() under the inode->i_lock. Now that we no longer call nfs_clear_request() until the nfs_page is being freed, we know that we are always holding a reference to the nfs_open_context, which again holds a reference to the path, and so the inode cannot be freed until the last nfs_page has been removed from the radix tree and freed. We can therefore skip the igrab()/iput() altogether. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/pagelist.c4
-rw-r--r--fs/nfs/write.c13
-rw-r--r--include/linux/nfs_page.h1
3 files changed, 5 insertions, 13 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 87a593c2b055..c80add6e2213 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -135,14 +135,14 @@ void nfs_clear_page_tag_locked(struct nfs_page *req)
135 nfs_unlock_request(req); 135 nfs_unlock_request(req);
136} 136}
137 137
138/** 138/*
139 * nfs_clear_request - Free up all resources allocated to the request 139 * nfs_clear_request - Free up all resources allocated to the request
140 * @req: 140 * @req:
141 * 141 *
142 * Release page and open context resources associated with a read/write 142 * Release page and open context resources associated with a read/write
143 * request after it has completed. 143 * request after it has completed.
144 */ 144 */
145void nfs_clear_request(struct nfs_page *req) 145static void nfs_clear_request(struct nfs_page *req)
146{ 146{
147 struct page *page = req->wb_page; 147 struct page *page = req->wb_page;
148 struct nfs_open_context *ctx = req->wb_context; 148 struct nfs_open_context *ctx = req->wb_context;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 85d75254328e..af0c6279a4a7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -389,11 +389,8 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
389 spin_lock(&inode->i_lock); 389 spin_lock(&inode->i_lock);
390 error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req); 390 error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req);
391 BUG_ON(error); 391 BUG_ON(error);
392 if (!nfsi->npages) { 392 if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE))
393 igrab(inode); 393 nfsi->change_attr++;
394 if (nfs_have_delegation(inode, FMODE_WRITE))
395 nfsi->change_attr++;
396 }
397 set_bit(PG_MAPPED, &req->wb_flags); 394 set_bit(PG_MAPPED, &req->wb_flags);
398 SetPagePrivate(req->wb_page); 395 SetPagePrivate(req->wb_page);
399 set_page_private(req->wb_page, (unsigned long)req); 396 set_page_private(req->wb_page, (unsigned long)req);
@@ -423,11 +420,7 @@ static void nfs_inode_remove_request(struct nfs_page *req)
423 clear_bit(PG_MAPPED, &req->wb_flags); 420 clear_bit(PG_MAPPED, &req->wb_flags);
424 radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); 421 radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
425 nfsi->npages--; 422 nfsi->npages--;
426 if (!nfsi->npages) { 423 spin_unlock(&inode->i_lock);
427 spin_unlock(&inode->i_lock);
428 iput(inode);
429 } else
430 spin_unlock(&inode->i_lock);
431 nfs_release_request(req); 424 nfs_release_request(req);
432} 425}
433 426
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 8023e4e25133..91af2e49fa3a 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -78,7 +78,6 @@ extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
78 struct page *page, 78 struct page *page,
79 unsigned int offset, 79 unsigned int offset,
80 unsigned int count); 80 unsigned int count);
81extern void nfs_clear_request(struct nfs_page *req);
82extern void nfs_release_request(struct nfs_page *req); 81extern void nfs_release_request(struct nfs_page *req);
83 82
84 83