From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f67.google.com ([209.85.221.67]:42614 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726611AbeHZUGi (ORCPT ); Sun, 26 Aug 2018 16:06:38 -0400 From: Amir Goldstein To: Miklos Szeredi Cc: Al Viro , Dave Chinner , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v2 5/6] vfs: fix fadvise64 syscall on an overlayfs file Date: Sun, 26 Aug 2018 19:25:16 +0300 Message-Id: <1535300717-26686-6-git-send-email-amir73il@gmail.com> In-Reply-To: <1535300717-26686-1-git-send-email-amir73il@gmail.com> References: <1535300717-26686-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: For an overlayfs file/inode, gage io is operating on the real underlying file, so the readahead hints set by fadvise64() should also be set on the real underlying file to take affect. Fixes: d1d04ef8572b ("ovl: stack file ops") Signed-off-by: Amir Goldstein --- mm/fadvise.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/mm/fadvise.c b/mm/fadvise.c index 2d8376e3c640..d5528343ce77 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -30,6 +30,7 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) { struct fd f = fdget(fd); + struct file *file; struct inode *inode; struct address_space *mapping; struct backing_dev_info *bdi; @@ -42,13 +43,18 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) if (!f.file) return -EBADF; - inode = file_inode(f.file); + /* + * XXX: We need to use file_real() for overlayfs stacked file because + * readahead will be operating on the real underlying file/inode. + */ + file = file_real(f.file); + inode = file_inode(file); if (S_ISFIFO(inode->i_mode)) { ret = -ESPIPE; goto out; } - mapping = f.file->f_mapping; + mapping = file->f_mapping; if (!mapping || len < 0) { ret = -EINVAL; goto out; @@ -85,21 +91,21 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) switch (advice) { case POSIX_FADV_NORMAL: - f.file->f_ra.ra_pages = bdi->ra_pages; - spin_lock(&f.file->f_lock); - f.file->f_mode &= ~FMODE_RANDOM; - spin_unlock(&f.file->f_lock); + file->f_ra.ra_pages = bdi->ra_pages; + spin_lock(&file->f_lock); + file->f_mode &= ~FMODE_RANDOM; + spin_unlock(&file->f_lock); break; case POSIX_FADV_RANDOM: - spin_lock(&f.file->f_lock); - f.file->f_mode |= FMODE_RANDOM; - spin_unlock(&f.file->f_lock); + spin_lock(&file->f_lock); + file->f_mode |= FMODE_RANDOM; + spin_unlock(&file->f_lock); break; case POSIX_FADV_SEQUENTIAL: - f.file->f_ra.ra_pages = bdi->ra_pages * 2; - spin_lock(&f.file->f_lock); - f.file->f_mode &= ~FMODE_RANDOM; - spin_unlock(&f.file->f_lock); + file->f_ra.ra_pages = bdi->ra_pages * 2; + spin_lock(&file->f_lock); + file->f_mode &= ~FMODE_RANDOM; + spin_unlock(&file->f_lock); break; case POSIX_FADV_WILLNEED: /* First and last PARTIAL page! */ @@ -115,7 +121,7 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) * Ignore return value because fadvise() shall return * success even if filesystem can't retrieve a hint, */ - force_page_cache_readahead(mapping, f.file, start_index, + force_page_cache_readahead(mapping, file, start_index, nrpages); break; case POSIX_FADV_NOREUSE: -- 2.7.4