| Message ID | 53F36C27.7050006@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 19 Aug 2014 23:24:23 +0800 Kinglong Mee <kinglongmee@gmail.com> wrote: > Commit d5b9026a67 ([PATCH] knfsd: locks: flag NFSv4-owned locks) using > fl_lmops field in file_lock for checking nfsd4 lockowner. > > But, commit 1a747ee0cc (locks: don't call ->copy_lock methods on return > of conflicting locks) causes the fl_lmops of conflock always be NULL. > > Also, commit 0996905f93 (lockd: posix_test_lock() should not call > locks_copy_lock()) caused the fl_lmops of conflock always be NULL too. > > Make sure copy the private information by fl_copy_lock() in struct > file_lock_operations, merge __locks_copy_lock() to fl_copy_lock(). > > Jeff advice, "Set fl_lmops on conflocks, but don't set fl_ops. > fl_ops are superfluous, since they are callbacks into the filesystem. > There should be no need to bother the filesystem at all with info > in a conflock. But, lock _ownership_ matters for conflocks and that's > indicated by the fl_lmops. So you really do want to copy the fl_lmops > for conflocks I think." > > v4: only copy fl_lmops for conflock, don't copy fl_ops > > Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> > --- > fs/locks.c | 36 ++++++++++++++++-------------------- > 1 file changed, 16 insertions(+), 20 deletions(-) > > diff --git a/fs/locks.c b/fs/locks.c > index c376561..0ee775d 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -271,21 +271,6 @@ void locks_init_lock(struct file_lock *fl) > > EXPORT_SYMBOL(locks_init_lock); > > -static void locks_copy_private(struct file_lock *new, struct file_lock *fl) > -{ > - if (fl->fl_ops) { > - if (fl->fl_ops->fl_copy_lock) > - fl->fl_ops->fl_copy_lock(new, fl); > - new->fl_ops = fl->fl_ops; > - } > - > - if (fl->fl_lmops) { > - if (fl->fl_lmops->lm_get_owner) > - fl->fl_lmops->lm_get_owner(new, fl); > - new->fl_lmops = fl->fl_lmops; > - } > -} > - > /* > * Initialize a new lock from an existing file_lock structure. > */ > @@ -298,8 +283,13 @@ void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) > new->fl_type = fl->fl_type; > new->fl_start = fl->fl_start; > new->fl_end = fl->fl_end; > + new->fl_lmops = fl->fl_lmops; > new->fl_ops = NULL; > - new->fl_lmops = NULL; > + > + if (fl->fl_lmops) { > + if (fl->fl_lmops->lm_get_owner) > + fl->fl_lmops->lm_get_owner(new, fl); > + } > } > EXPORT_SYMBOL(locks_copy_conflock); > > @@ -309,11 +299,14 @@ void locks_copy_lock(struct file_lock *new, struct file_lock *fl) > WARN_ON_ONCE(new->fl_ops); > > locks_copy_conflock(new, fl); > + > new->fl_file = fl->fl_file; > new->fl_ops = fl->fl_ops; > - new->fl_lmops = fl->fl_lmops; > > - locks_copy_private(new, fl); > + if (fl->fl_ops) { > + if (fl->fl_ops->fl_copy_lock) > + fl->fl_ops->fl_copy_lock(new, fl); > + } > } > > EXPORT_SYMBOL(locks_copy_lock); > @@ -1989,11 +1982,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) > if (file_lock.fl_type != F_UNLCK) { > error = posix_lock_to_flock(&flock, &file_lock); > if (error) > - goto out; > + goto rel_priv; > } > error = -EFAULT; > if (!copy_to_user(l, &flock, sizeof(flock))) > error = 0; > +rel_priv: > + locks_release_private(&file_lock); > out: > return error; > } > @@ -2214,7 +2209,8 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) > error = -EFAULT; > if (!copy_to_user(l, &flock, sizeof(flock))) > error = 0; > - > + > + locks_release_private(&file_lock); > out: > return error; > } Looks good for the most part. I think there is one small piece missing though. There is a vfs_test_lock call in nlmsvc_testlock. The conflock in that case is embedded inside a nlm_lock and locks_release_private is not called on it (AFAICT). You're not planning to set these new lmops for lockd, but someone could in the future. I think it would be good to go ahead and plumb in a call to locks_release_private there as well to help ensure that no one will break this in the future. It'll be a no-op for the time being of course.
diff --git a/fs/locks.c b/fs/locks.c index c376561..0ee775d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -271,21 +271,6 @@ void locks_init_lock(struct file_lock *fl) EXPORT_SYMBOL(locks_init_lock); -static void locks_copy_private(struct file_lock *new, struct file_lock *fl) -{ - if (fl->fl_ops) { - if (fl->fl_ops->fl_copy_lock) - fl->fl_ops->fl_copy_lock(new, fl); - new->fl_ops = fl->fl_ops; - } - - if (fl->fl_lmops) { - if (fl->fl_lmops->lm_get_owner) - fl->fl_lmops->lm_get_owner(new, fl); - new->fl_lmops = fl->fl_lmops; - } -} - /* * Initialize a new lock from an existing file_lock structure. */ @@ -298,8 +283,13 @@ void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) new->fl_type = fl->fl_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; + new->fl_lmops = fl->fl_lmops; new->fl_ops = NULL; - new->fl_lmops = NULL; + + if (fl->fl_lmops) { + if (fl->fl_lmops->lm_get_owner) + fl->fl_lmops->lm_get_owner(new, fl); + } } EXPORT_SYMBOL(locks_copy_conflock); @@ -309,11 +299,14 @@ void locks_copy_lock(struct file_lock *new, struct file_lock *fl) WARN_ON_ONCE(new->fl_ops); locks_copy_conflock(new, fl); + new->fl_file = fl->fl_file; new->fl_ops = fl->fl_ops; - new->fl_lmops = fl->fl_lmops; - locks_copy_private(new, fl); + if (fl->fl_ops) { + if (fl->fl_ops->fl_copy_lock) + fl->fl_ops->fl_copy_lock(new, fl); + } } EXPORT_SYMBOL(locks_copy_lock); @@ -1989,11 +1982,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) if (file_lock.fl_type != F_UNLCK) { error = posix_lock_to_flock(&flock, &file_lock); if (error) - goto out; + goto rel_priv; } error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; +rel_priv: + locks_release_private(&file_lock); out: return error; } @@ -2214,7 +2209,8 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; - + + locks_release_private(&file_lock); out: return error; }
Commit d5b9026a67 ([PATCH] knfsd: locks: flag NFSv4-owned locks) using fl_lmops field in file_lock for checking nfsd4 lockowner. But, commit 1a747ee0cc (locks: don't call ->copy_lock methods on return of conflicting locks) causes the fl_lmops of conflock always be NULL. Also, commit 0996905f93 (lockd: posix_test_lock() should not call locks_copy_lock()) caused the fl_lmops of conflock always be NULL too. Make sure copy the private information by fl_copy_lock() in struct file_lock_operations, merge __locks_copy_lock() to fl_copy_lock(). Jeff advice, "Set fl_lmops on conflocks, but don't set fl_ops. fl_ops are superfluous, since they are callbacks into the filesystem. There should be no need to bother the filesystem at all with info in a conflock. But, lock _ownership_ matters for conflocks and that's indicated by the fl_lmops. So you really do want to copy the fl_lmops for conflocks I think." v4: only copy fl_lmops for conflock, don't copy fl_ops Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> --- fs/locks.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-)