On Fri, Jan 26, 2024 at 02:48:45PM -0800, Linus Torvalds wrote: > On Fri, 26 Jan 2024 at 14:34, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > On Fri, Jan 26, 2024 at 05:14:12PM -0500, Mathieu Desnoyers wrote: > > > I would suggest this straightforward solution to this: > > > > > > a) define a EVENTFS_MAX_INODES (e.g. 4096 * 8), > > > > > > b) keep track of inode allocation in a bitmap (within a single page), > > > > > > c) disallow allocating more than "EVENTFS_MAX_INODES" in eventfs. > > > > ... reinventing the IDA? > > Guysm, this is a random number that is *so* interesting that I > seriously think we shouldn't have it at all. > > End result: nobody should care. Even the general VFS layer doesn't care. > > It literally avoids inode number zero, not because it would be a bad > inode number, but simply because of some random historical oddity. > > In fact, I don't think we even have a reason for it. We have a commit > 2adc376c5519 ("vfs: avoid creation of inode number 0 in get_next_ino") > and that one calls out glibc for not deleting them. That makes no > sense to me, but whatever. Maybe we should take advantage of that historical oddity. All files in eventfs have inode number 0, problem solved.