| Message ID | 20221116112658.8793-1-jlayton@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | filelock: new helper: vfs_inode_has_locks | expand |
On 16/11/2022 19:26, Jeff Layton wrote: > Ceph has a need to know whether a particular inode has any locks set on > it. It's currently tracking that by a num_locks field in its > filp->private_data, but that's problematic as it tries to decrement this > field when releasing locks and that can race with the file being torn > down. > > Add a new vfs_inode_has_locks helper that just returns whether any locks > are currently held on the inode. > > Cc: Xiubo Li <xiubli@redhat.com> > Reviewed-by: Christoph Hellwig <hch@infradead.org> > Signed-off-by: Jeff Layton <jlayton@kernel.org> > --- > fs/locks.c | 23 +++++++++++++++++++++++ > include/linux/fs.h | 1 + > 2 files changed, 24 insertions(+) > > diff --git a/fs/locks.c b/fs/locks.c > index 5876c8ff0edc..9ccf89b6c95d 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -2672,6 +2672,29 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) > } > EXPORT_SYMBOL_GPL(vfs_cancel_lock); > > +/** > + * vfs_inode_has_locks - are any file locks held on @inode? > + * @inode: inode to check for locks > + * > + * Return true if there are any FL_POSIX or FL_FLOCK locks currently > + * set on @inode. > + */ > +bool vfs_inode_has_locks(struct inode *inode) > +{ > + struct file_lock_context *ctx; > + bool ret; > + > + ctx = smp_load_acquire(&inode->i_flctx); > + if (!ctx) > + return false; > + > + spin_lock(&ctx->flc_lock); > + ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock); > + spin_unlock(&ctx->flc_lock); > + return ret; > +} > +EXPORT_SYMBOL_GPL(vfs_inode_has_locks); > + > #ifdef CONFIG_PROC_FS > #include <linux/proc_fs.h> > #include <linux/seq_file.h> > diff --git a/include/linux/fs.h b/include/linux/fs.h > index e654435f1651..d6cb42b7e91c 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1170,6 +1170,7 @@ extern int locks_delete_block(struct file_lock *); > extern int vfs_test_lock(struct file *, struct file_lock *); > extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); > extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); > +bool vfs_inode_has_locks(struct inode *inode); > extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); > extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); > extern void lease_get_mtime(struct inode *, struct timespec64 *time); Reviewed-by: Xiubo Li <xiubli@redhat.com> I will send the V3 patch series to fix the ceph's filelock bug basing on this. Thanks Jeff. - Xiubo
Jeff, I have tested this and it worked very well for ceph. Tested-by: Xiubo Li <xiubli@redhat.com> Thanks! - Xiubo On 16/11/2022 19:26, Jeff Layton wrote: > Ceph has a need to know whether a particular inode has any locks set on > it. It's currently tracking that by a num_locks field in its > filp->private_data, but that's problematic as it tries to decrement this > field when releasing locks and that can race with the file being torn > down. > > Add a new vfs_inode_has_locks helper that just returns whether any locks > are currently held on the inode. > > Cc: Xiubo Li <xiubli@redhat.com> > Reviewed-by: Christoph Hellwig <hch@infradead.org> > Signed-off-by: Jeff Layton <jlayton@kernel.org> > --- > fs/locks.c | 23 +++++++++++++++++++++++ > include/linux/fs.h | 1 + > 2 files changed, 24 insertions(+) > > diff --git a/fs/locks.c b/fs/locks.c > index 5876c8ff0edc..9ccf89b6c95d 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -2672,6 +2672,29 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) > } > EXPORT_SYMBOL_GPL(vfs_cancel_lock); > > +/** > + * vfs_inode_has_locks - are any file locks held on @inode? > + * @inode: inode to check for locks > + * > + * Return true if there are any FL_POSIX or FL_FLOCK locks currently > + * set on @inode. > + */ > +bool vfs_inode_has_locks(struct inode *inode) > +{ > + struct file_lock_context *ctx; > + bool ret; > + > + ctx = smp_load_acquire(&inode->i_flctx); > + if (!ctx) > + return false; > + > + spin_lock(&ctx->flc_lock); > + ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock); > + spin_unlock(&ctx->flc_lock); > + return ret; > +} > +EXPORT_SYMBOL_GPL(vfs_inode_has_locks); > + > #ifdef CONFIG_PROC_FS > #include <linux/proc_fs.h> > #include <linux/seq_file.h> > diff --git a/include/linux/fs.h b/include/linux/fs.h > index e654435f1651..d6cb42b7e91c 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1170,6 +1170,7 @@ extern int locks_delete_block(struct file_lock *); > extern int vfs_test_lock(struct file *, struct file_lock *); > extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); > extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); > +bool vfs_inode_has_locks(struct inode *inode); > extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); > extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); > extern void lease_get_mtime(struct inode *, struct timespec64 *time);
diff --git a/fs/locks.c b/fs/locks.c index 5876c8ff0edc..9ccf89b6c95d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2672,6 +2672,29 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) } EXPORT_SYMBOL_GPL(vfs_cancel_lock); +/** + * vfs_inode_has_locks - are any file locks held on @inode? + * @inode: inode to check for locks + * + * Return true if there are any FL_POSIX or FL_FLOCK locks currently + * set on @inode. + */ +bool vfs_inode_has_locks(struct inode *inode) +{ + struct file_lock_context *ctx; + bool ret; + + ctx = smp_load_acquire(&inode->i_flctx); + if (!ctx) + return false; + + spin_lock(&ctx->flc_lock); + ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock); + spin_unlock(&ctx->flc_lock); + return ret; +} +EXPORT_SYMBOL_GPL(vfs_inode_has_locks); + #ifdef CONFIG_PROC_FS #include <linux/proc_fs.h> #include <linux/seq_file.h> diff --git a/include/linux/fs.h b/include/linux/fs.h index e654435f1651..d6cb42b7e91c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1170,6 +1170,7 @@ extern int locks_delete_block(struct file_lock *); extern int vfs_test_lock(struct file *, struct file_lock *); extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); +bool vfs_inode_has_locks(struct inode *inode); extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); extern void lease_get_mtime(struct inode *, struct timespec64 *time);