On Tue, 2023-06-20 at 16:00 +0500, stsp wrote: > Hello, > > 20.06.2023 15:46, Jeff Layton пишет: > > On Tue, 2023-06-20 at 14:55 +0500, Stas Sergeev wrote: > > > Currently F_UNLCK with F_OFD_GETLK returns -EINVAL. > > > The proposed extension allows to use it for getting the lock > > > information from the particular fd. > > > > > > Signed-off-by: Stas Sergeev <stsp2@xxxxxxxxx> > > > > > > CC: Jeff Layton <jlayton@xxxxxxxxxx> > > > CC: Chuck Lever <chuck.lever@xxxxxxxxxx> > > > CC: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> > > > CC: Christian Brauner <brauner@xxxxxxxxxx> > > > CC: linux-fsdevel@xxxxxxxxxxxxxxx > > > CC: linux-kernel@xxxxxxxxxxxxxxx > > > > > > --- > > > fs/locks.c | 23 ++++++++++++++++++++--- > > > 1 file changed, 20 insertions(+), 3 deletions(-) > > > > > > diff --git a/fs/locks.c b/fs/locks.c > > > index df8b26a42524..210766007e63 100644 > > > --- a/fs/locks.c > > > +++ b/fs/locks.c > > > @@ -868,6 +868,21 @@ static bool posix_locks_conflict(struct file_lock *caller_fl, > > > return locks_conflict(caller_fl, sys_fl); > > > } > > > > > > +/* Determine if lock sys_fl blocks lock caller_fl. Used on xx_GETLK > > > + * path so checks for additional GETLK-specific things like F_UNLCK. > > > + */ > > > +static bool posix_test_locks_conflict(struct file_lock *caller_fl, > > > + struct file_lock *sys_fl) > > > +{ > > > + /* F_UNLCK checks any locks on the same fd. */ > > > + if (caller_fl->fl_type == F_UNLCK) { > > > + if (!posix_same_owner(caller_fl, sys_fl)) > > > + return false; > > > + return locks_overlap(caller_fl, sys_fl); > > > + } > > > + return posix_locks_conflict(caller_fl, sys_fl); > > > +} > > > + > > > /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific > > > * checking before calling the locks_conflict(). > > > */ > > > @@ -901,7 +916,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl) > > > retry: > > > spin_lock(&ctx->flc_lock); > > > list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { > > > - if (!posix_locks_conflict(fl, cfl)) > > > + if (!posix_test_locks_conflict(fl, cfl)) > > > continue; > > > if (cfl->fl_lmops && cfl->fl_lmops->lm_lock_expirable > > > && (*cfl->fl_lmops->lm_lock_expirable)(cfl)) { > > > @@ -2207,7 +2222,8 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) > > > if (fl == NULL) > > > return -ENOMEM; > > > error = -EINVAL; > > > - if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) > > > + if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK > > > + && flock->l_type != F_WRLCK) > > > goto out; > > > > > > error = flock_to_posix_lock(filp, fl, flock); > > > @@ -2414,7 +2430,8 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) > > > return -ENOMEM; > > > > > > error = -EINVAL; > > > - if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) > > > + if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK > > > + && flock->l_type != F_WRLCK) > > > goto out; > > > > > > error = flock64_to_posix_lock(filp, fl, flock); > > This seems like a reasonable sort of interface to add, particularly for > > the CRIU case. > > Just for the record: my own cases are > the remaining 2. CRIU case is not mine > and I haven't talked to CRIU people > about that. > > > > Using F_UNLCK for this is a bit kludgey, but adding a new > > constant is probably worse. > > > > I'm willing to take this in with an eye toward v6.6. Are you also > > willing to draft up some manpage patches that detail this new interface? > Sure thing. > As soon as its applied, I'll prepare a man > patch, or should it be done before that point? These days, it's a good idea to go ahead and draft that up early. You'll be surprised what sort of details you notice once you have to start writing documentation. ;) You can post it as part of this set on the next posting and just mention that it's a draft manpage patch. You should also include the linux-api mailing list on the next posting so we get some feedback on the interface itself. -- Jeff Layton <jlayton@xxxxxxxxxx>