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-rw-r--r--fs/nfs/write.c40
1 files changed, 22 insertions, 18 deletions
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 08c1ce968cce..ff7c90c7ff79 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -372,15 +372,14 @@ nfs_page_group_clear_bits(struct nfs_page *req)
* @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
*
- * NOTE: this must be called holding page_group bit lock and inode spin lock
- * and BOTH will be released before returning.
+ * NOTE: this must be called holding page_group bit lock
+ * which will be released before returning.
*
* returns 0 on success, < 0 on error.
*/
static int
nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
struct nfs_page *req)
- __releases(&inode->i_lock)
{
struct nfs_page *tmp;
int ret;
@@ -395,7 +394,6 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
kref_get(&req->wb_kref);
nfs_page_group_unlock(head);
- spin_unlock(&inode->i_lock);
/* release ref from nfs_page_find_head_request_locked */
nfs_unlock_and_release_request(head);
@@ -491,8 +489,9 @@ nfs_lock_and_join_requests(struct page *page)
int ret;
try_again:
+ if (!(PagePrivate(page) || PageSwapCache(page)))
+ return NULL;
spin_lock(&inode->i_lock);
-
/*
* A reference is taken only on the head request which acts as a
* reference to the whole page group - the group will not be destroyed
@@ -514,16 +513,12 @@ try_again:
return ERR_PTR(ret);
goto try_again;
}
+ spin_unlock(&inode->i_lock);
- /* holding inode lock, so always make a non-blocking call to try the
- * page group lock */
- ret = nfs_page_group_lock(head, true);
+ ret = nfs_page_group_lock(head, false);
if (ret < 0) {
- spin_unlock(&inode->i_lock);
-
- nfs_page_group_lock_wait(head);
nfs_unlock_and_release_request(head);
- goto try_again;
+ return ERR_PTR(ret);
}
/* lock each request in the page group */
@@ -531,8 +526,10 @@ try_again:
for (subreq = head->wb_this_page; subreq != head;
subreq = subreq->wb_this_page) {
if (!nfs_lock_request(subreq)) {
- /* releases page group bit lock and
- * inode spin lock and all references */
+ /*
+ * releases page group bit lock and
+ * page locks and all references
+ */
ret = nfs_unroll_locks_and_wait(inode, head,
subreq);
@@ -580,7 +577,9 @@ try_again:
if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) {
set_bit(PG_INODE_REF, &head->wb_flags);
kref_get(&head->wb_kref);
+ spin_lock(&inode->i_lock);
NFS_I(inode)->nrequests++;
+ spin_unlock(&inode->i_lock);
}
/*
@@ -590,11 +589,14 @@ try_again:
nfs_page_group_unlock(head);
- /* drop lock to clean uprequests on destroy list */
- spin_unlock(&inode->i_lock);
-
nfs_destroy_unlinked_subrequests(destroy_list, head, inode);
+ /* Did we lose a race with nfs_inode_remove_request()? */
+ if (!(PagePrivate(page) || PageSwapCache(page))) {
+ nfs_unlock_and_release_request(head);
+ return NULL;
+ }
+
/* still holds ref on head from nfs_page_find_head_request_locked
* and still has lock on head from lock loop */
return head;
@@ -968,7 +970,7 @@ nfs_clear_page_commit(struct page *page)
WB_RECLAIMABLE);
}
-/* Called holding inode (/cinfo) lock */
+/* Called holding the request lock on @req */
static void
nfs_clear_request_commit(struct nfs_page *req)
{
@@ -977,9 +979,11 @@ nfs_clear_request_commit(struct nfs_page *req)
struct nfs_commit_info cinfo;
nfs_init_cinfo_from_inode(&cinfo, inode);
+ spin_lock(&inode->i_lock);
if (!pnfs_clear_request_commit(req, &cinfo)) {
nfs_request_remove_commit_list(req, &cinfo);
}
+ spin_unlock(&inode->i_lock);
nfs_clear_page_commit(req->wb_page);
}
}