Yes it is possible to mount file and it is call a bind mount. See man page of mount, and it is used in pratice essentially for /dev/null but it could be used for any regular file
Le 3 oct. 2011 19:29, "Kamil Dudka" <kdu...@redhat.com> a écrit : On Monday 03 October 2011 18:25:10 Bruno Haible wrote: > Kamil Dudka wrote: > > > 2) see a test ca... Fair enough. I am adding this to my TODO list, although there are more urgent issues preventing me from working on this atm. > Thanks for that background. So we're looking at "ls -l /media" or > "ls -ld mountpoint". Since yo... Well, symlinks to mount points were not mentioned in that bug. I would need to ask kernel guys whether symlinks to mount points are worth to consider in this fix at all. > So in fact we have 9 cases: > a) A non-symlink, non-directory. Here acl_extended_file_nofollow ... If I understand this, you expect non-directories cannot be mount points, thus the call cannot trigger the mount, right? > b) A directory that is not a mount point. > c) A mount point. > d) A symlink to a file, wit... The behavior of ls wrt. tregerring mounts is implementation defined, isn't it? Let's take it such and just choose the implementaion that makes sense. > So how do these 9 cases need to be handled: > a) Either acl_extended_file_nofollow or acl_exten... The Problem is that case a) is not detectable on its own. > I'm trying to avoid useless system calls. If > ! S_ISLNK (sb->st_mode) && ! S_ISDIR (sb->st_mo... Is optimization the only purpose of this change? I would then prefer to get it working first and optimize it later on. > But still still does not fix the problem of case f). Here, with your > current patch, "ls -lLd sy... Case f) has never worked, nobody complained. Partial fix is better than no fix. The last patch does not break anything that worked before, does it? > IMO, there are two solutions to this: > - Either convince the kernel people to introduce a diff... This is non-starter. Kernel developers are not interested in optimizing out stat() calls from user-space. There is a similar, more serious, bug open for years. Nobody cares. https://bugzilla.redhat.com/501848 > - Or use code equivalent to canonicalize_filename_mode(CAN_EXISTING). I am personally not intersted in changing something that works unless there is a user that needs the change actually. Kamil
