On Tue, Jun 5, 2018 at 2:36 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Mon, Jun 4, 2018 at 10:48 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: >> On Tue, May 29, 2018 at 04:43:06PM +0200, Miklos Szeredi wrote: >>> This is needed by overlayfs to be able to copy up a file from a read-only >>> lower layer to a writable layer when being mapped shared. When copying up, >>> overlayfs takes VFS locks that would violate locking order when nested >>> inside mmap_sem. >>> >>> Add a new f_op->pre_mmap method, which is called before taking mmap_sem. >> >> NAK. We really should not add multiple methods for mmap, and everytime >> this came up we found a better way to solve the problem instead. Most >> recent example was the socket zero copy receive code. > > Okay, I'll drop this. Need to remove copy_up_shared from overlayfs.txt. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
