From 955fbe0ef19df4197595a98d0906c94025c4beef Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 12 Mar 2025 08:38:50 +0100 Subject: Revert "fsnotify: generate pre-content permission event on page fault" This reverts commit 8392bc2ff8c8bf7c4c5e6dfa71ccd893a3c046f6. In the use case of buffered write whose input buffer is mmapped file on a filesystem with a pre-content mark, the prefaulting of the buffer can happen under the filesystem freeze protection (obtained in vfs_write()) which breaks assumptions of pre-content hook and introduces potential deadlock of HSM handler in userspace with filesystem freezing. Now that we have pre-content hooks at file mmap() time, disable the pre-content event hooks on page fault to avoid the potential deadlock. Reported-by: syzbot+7229071b47908b19d5b7@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-fsdevel/7ehxrhbvehlrjwvrduoxsao5k3x4aw275patsb3krkwuq573yv@o2hskrfawbnc/ Fixes: 8392bc2ff8c8 ("fsnotify: generate pre-content permission event on page fault") Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250312073852.2123409-5-amir73il@gmail.com --- include/linux/mm.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 7b1068ddcbb7..8483e09aeb2c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3420,7 +3420,6 @@ extern vm_fault_t filemap_fault(struct vm_fault *vmf); extern vm_fault_t filemap_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff); extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf); -extern vm_fault_t filemap_fsnotify_fault(struct vm_fault *vmf); extern unsigned long stack_guard_gap; /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */ -- cgit v1.2.3