From fd2f3a06d30c85a17cf035ebc60c88c2a13a8ece Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 8 Aug 2014 11:00:53 -0400 Subject: nfs: change nfs_page_group_lock argument Flip the meaning of the second argument from 'wait' to 'nonblock' to match related functions. Update all five calls to reflect this change. Signed-off-by: Weston Andros Adamson Reviewed-by: Peng Tao Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index e3b5cf28bdc5..27715306f24b 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -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); @@ -479,7 +479,7 @@ try_again: } /* lock each request in the page group */ - ret = nfs_page_group_lock(head, false); + ret = nfs_page_group_lock(head, true); if (ret < 0) return ERR_PTR(ret); subreq = head; -- cgit v1.2.3 From 94970014c46223cbcdfbfc67b89596a412f9e3dd Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 8 Aug 2014 11:00:56 -0400 Subject: nfs: fix error handling in lock_and_join_requests This fixes handling of errors from nfs_page_group_lock in nfs_lock_and_join_requests. It now releases the inode lock and the reference to the head request. Reported-by: Peng Tao Signed-off-by: Weston Andros Adamson Reviewed-by: Peng Tao Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 27715306f24b..e056f617adf2 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -480,8 +480,11 @@ try_again: /* lock each request in the page group */ ret = nfs_page_group_lock(head, true); - if (ret < 0) + if (ret < 0) { + spin_unlock(&inode->i_lock); + nfs_release_request(head); return ERR_PTR(ret); + } subreq = head; do { /* -- cgit v1.2.3 From 7c3af975257383ece54b83c0505d3e0656cb7daf Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 8 Aug 2014 11:00:57 -0400 Subject: nfs: don't sleep with inode lock in lock_and_join_requests This handles the 'nonblock=false' case in nfs_lock_and_join_requests. If the group is already locked and blocking is allowed, drop the inode lock and wait for the group lock to be cleared before trying it all again. This should fix warnings found in peterz's tree (sched/wait branch), where might_sleep() checks are added to wait.[ch]. Reported-by: Fengguang Wu Signed-off-by: Weston Andros Adamson Reviewed-by: Peng Tao Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 17 +++++++++++++++++ fs/nfs/write.c | 12 +++++++++++- include/linux/nfs_page.h | 1 + 3 files changed, 29 insertions(+), 1 deletion(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 30c9626f96b0..4ec67f8d70aa 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -167,6 +167,23 @@ nfs_page_group_lock(struct nfs_page *req, bool nonblock) 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); +} + /* * nfs_page_group_unlock - unlock the head of the page group * @req - request in group that is to be unlocked diff --git a/fs/nfs/write.c b/fs/nfs/write.c index e056f617adf2..175d5d073ccf 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -478,13 +478,23 @@ try_again: return NULL; } - /* lock each request in the page group */ + /* 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 { /* diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 6ad2bbcad405..6c3e06ee2fb7 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -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); -- cgit v1.2.3