From 09b696bd214915ca72a5d0925690580292bde00c Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 18 Jun 2020 18:43:53 +0300 Subject: [PATCH] ovl: fix unneeded call to ovl_change_flags() commit 81a33c1ee941c3bb9ffc6bac8f676be13351344e upstream. The check if user has changed the overlay file was wrong, causing unneeded call to ovl_change_flags() including taking f_lock on every file access. Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path") Cc: # v4.19+ Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/file.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 15e4fa288475..7a08a576f7b2 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -21,13 +21,16 @@ static char ovl_whatisit(struct inode *inode, struct inode *realinode) return 'm'; } +/* No atime modificaton nor notify on underlying */ +#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY) + static struct file *ovl_open_realfile(const struct file *file, struct inode *realinode) { struct inode *inode = file_inode(file); struct file *realfile; const struct cred *old_cred; - int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY; + int flags = file->f_flags | OVL_OPEN_FLAGS; old_cred = ovl_override_creds(inode->i_sb); realfile = open_with_fake_path(&file->f_path, flags, realinode, @@ -48,8 +51,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags) struct inode *inode = file_inode(file); int err; - /* No atime modificaton on underlying */ - flags |= O_NOATIME | FMODE_NONOTIFY; + flags |= OVL_OPEN_FLAGS; /* If some flag changed that cannot be changed then something's amiss */ if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK)) @@ -102,7 +104,7 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real, } /* Did the flags change since open? */ - if (unlikely((file->f_flags ^ real->file->f_flags) & ~O_NOATIME)) + if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS)) return ovl_change_flags(real->file, file->f_flags); return 0;