From 9620ad86d0e3e8fda4a23efc22e0b2ae4ded1105 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Wed, 16 Jun 2021 22:22:28 +0100 Subject: afs: Re-enable freezing once a page fault is interrupted If a task is killed during a page fault, it does not currently call sb_end_pagefault(), which means that the filesystem cannot be frozen at any time thereafter. This may be reported by lockdep like this: ==================================== WARNING: fsstress/10757 still has locks held! 5.13.0-rc4-build4+ #91 Not tainted ------------------------------------ 1 lock held by fsstress/10757: #0: ffff888104eac530 ( sb_pagefaults as filesystem freezing is modelled as a lock. Fix this by removing all the direct returns from within the function, and using 'ret' to indicate whether we were interrupted or successful. Fixes: 1cf7a1518aef ("afs: Implement shared-writeable mmap") Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: David Howells cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20210616154900.1958373-1-willy@infradead.org/ Signed-off-by: Linus Torvalds --- fs/afs/write.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/afs/write.c b/fs/afs/write.c index a523bb86915d..e9ccaa3baf2e 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -837,6 +837,7 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) struct inode *inode = file_inode(file); struct afs_vnode *vnode = AFS_FS_I(inode); unsigned long priv; + vm_fault_t ret = VM_FAULT_RETRY; _enter("{{%llx:%llu}},{%lx}", vnode->fid.vid, vnode->fid.vnode, page->index); @@ -848,14 +849,14 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) #ifdef CONFIG_AFS_FSCACHE if (PageFsCache(page) && wait_on_page_fscache_killable(page) < 0) - return VM_FAULT_RETRY; + goto out; #endif if (wait_on_page_writeback_killable(page)) - return VM_FAULT_RETRY; + goto out; if (lock_page_killable(page) < 0) - return VM_FAULT_RETRY; + goto out; /* We mustn't change page->private until writeback is complete as that * details the portion of the page we need to write back and we might @@ -863,7 +864,7 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) */ if (wait_on_page_writeback_killable(page) < 0) { unlock_page(page); - return VM_FAULT_RETRY; + goto out; } priv = afs_page_dirty(page, 0, thp_size(page)); @@ -877,8 +878,10 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) } file_update_time(file); + ret = VM_FAULT_LOCKED; +out: sb_end_pagefault(inode->i_sb); - return VM_FAULT_LOCKED; + return ret; } /* -- cgit v1.2.3