On Thu, Nov 24, 2022 at 04:47:56PM +0100, Thorsten Leemhuis wrote: > Hi, this is your Linux kernel regression tracker speaking. > > I noticed a regression report in bugzilla.kernel.org. As many (most?) > kernel developer don't keep an eye on it, I decided to forward it by > mail. Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=216738 : > > > Pierre Labastie 2022-11-24 14:53:33 UTC > > > > Created attachment 303287 [details] > > C program for reproducing the bug > > > > Not sure this is the right place to report this, but at least the offending commit > > [offending commit is 164f4064ca8 ("keep iocb_flags() result cached in > struct file"), as specified in the "Kernel Version:" field in bugzilla] So basically we have this static int ovl_change_flags(struct file *file, unsigned int flags) { struct inode *inode = file_inode(file); int err; flags &= OVL_SETFL_MASK; if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) return -EPERM; if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT)) return -EINVAL; if (file->f_op->check_flags) { err = file->f_op->check_flags(flags); if (err) return err; } spin_lock(&file->f_lock); file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags; spin_unlock(&file->f_lock); return 0; } open-coding what setfl() would've done, without updating ->f_iocb_flags... Not hard to deal with... I could pick it in vfs.git #fixes, or Miklos could put it through his tree. Miklos, which way would you prefer that to go? [PATCH] update ->f_iocb_flags when ovl_change_flags() modifies ->f_flags ovl_change_flags() is an open-coded variant of fs/fcntl.c:setfl() and it got missed by 164f4064ca81e "keep iocb_flags() result cached in struct file"; the same change applies there. Reported-by: Pierre Labastie <pierre.labastie@xxxxxxx> Fixes: 164f4064ca81e "keep iocb_flags() result cached in struct file" Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> --- diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index a1a22f58ba18..dd688a842b0b 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -96,6 +96,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags) spin_lock(&file->f_lock); file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags; + file->f_iocb_flags = iocb_flags(file); spin_unlock(&file->f_lock); return 0;
