On Thu, Aug 28, 2025 at 10:26:10PM +0000, Eric Biggers wrote: > On Thu, Aug 28, 2025 at 02:25:21PM +0200, Christian Brauner wrote: > > On Tue, Aug 26, 2025 at 11:39:30AM -0400, Josef Bacik wrote: > > > Instead of checking for I_WILL_FREE|I_FREEING simply use the refcount to > > > make sure we have a live inode. > > > > > > Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > > --- > > I have no idea how the lifetime of such decrypted inodes are managed. > > I suppose they don't carry a separate reference but are still somehow > > safe to be accessed based on the mk_decrypted_inodes list. In any case > > something must hold an i_obj_count if we want to use igrab() since I > > don't see any relevant rcu protection here. > > > > inodes are placed on mk_decrypted_inodes by the filesystem while it's > holding an i_count reference, and they're removed from the list by > ->evict_inode shortly after i_count reaches zero. So the corresponding > i_obj_count reference is just the one associated with i_count. > > This patch looks correct: we do igrab() while holding > mk_decrypted_inodes_lock. So either i_count is nonzero and we get a > temporary i_count reference, or it's zero and we skip the inode since it > cannot have dentries (and ->evict_inode is coming very soon as well). Thanks for the explanation, Eric! That was exactly what I was looking for.
