| Message ID | 20230823213352.1971009-2-aahringo@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lockd: dlm: async lock request changes | expand |
On Wed, Aug 23, 2023 at 05:33:46PM -0400, Alexander Aring wrote: > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > export flag to signal that the "own ->lock" implementation supports > async lock requests. The only main user is DLM that is used by GFS2 and > OCFS2 filesystem. Those implement their own lock() implementation and > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > ("nfs: block notification on fs with its own ->lock") the DLM > implementation were never updated. This patch should prepare for DLM > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > plock implementation regarding to it. > > Acked-by: Jeff Layton <jlayton@kernel.org> > Signed-off-by: Alexander Aring <aahringo@redhat.com> > --- > fs/lockd/svclock.c | 5 ++--- > fs/nfsd/nfs4state.c | 13 ++++++++++--- > include/linux/exportfs.h | 8 ++++++++ > 3 files changed, 20 insertions(+), 6 deletions(-) I'm starting to look at these. Just so you know, it's too late for inclusion in v6.6, but I think we can get these into shape for v6.7. More below. > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > index c43ccdf28ed9..6e3b230e8317 100644 > --- a/fs/lockd/svclock.c > +++ b/fs/lockd/svclock.c > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > struct nlm_host *host, struct nlm_lock *lock, int wait, > struct nlm_cookie *cookie, int reclaim) > { > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > struct inode *inode = nlmsvc_file_inode(file); > -#endif > struct nlm_block *block = NULL; > int error; > int mode; > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > (long long)lock->fl.fl_end, > wait); > > - if (nlmsvc_file_file(file)->f_op->lock) { > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > + nlmsvc_file_file(file)->f_op)) { > async_block = wait; > wait = 0; > } > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index 3aefbad4cc09..14ca06424ff1 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -7430,6 +7430,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > struct nfsd4_blocked_lock *nbl = NULL; > struct file_lock *file_lock = NULL; > struct file_lock *conflock = NULL; > + struct super_block *sb; > __be32 status = 0; > int lkflg; > int err; > @@ -7451,6 +7452,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > dprintk("NFSD: nfsd4_lock: permission denied!\n"); > return status; > } > + sb = cstate->current_fh.fh_dentry->d_sb; > > if (lock->lk_is_new) { > if (nfsd4_has_session(cstate)) > @@ -7502,7 +7504,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > fp = lock_stp->st_stid.sc_file; > switch (lock->lk_type) { > case NFS4_READW_LT: > - if (nfsd4_has_session(cstate)) > + if (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_READ_LT: > @@ -7514,7 +7518,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > fl_type = F_RDLCK; > break; > case NFS4_WRITEW_LT: > - if (nfsd4_has_session(cstate)) > + if (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_WRITE_LT: > @@ -7542,7 +7548,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > * for file locks), so don't attempt blocking lock notifications > * on those filesystems: > */ > - if (nf->nf_file->f_op->lock) > + if (!export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags &= ~FL_SLEEP; > > nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); > diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h > index 11fbd0ee1370..10358a93cdc1 100644 > --- a/include/linux/exportfs.h > +++ b/include/linux/exportfs.h > @@ -3,6 +3,7 @@ > #define LINUX_EXPORTFS_H 1 > > #include <linux/types.h> > +#include <linux/fs.h> > > struct dentry; > struct iattr; > @@ -224,9 +225,16 @@ struct export_operations { > atomic attribute updates > */ > #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ > +#define EXPORT_OP_SAFE_ASYNC_LOCK (0x40) /* fs can do async lock request */ We haven't been good about this recently, but the addition of new EXPORT_OP flags need to be accompanied by updates to Documentation/filesystems/nfs/exporting.rst. I will see about adding documentation for other recent flags, but please include an update to exporting.rst with this patch. I'm not sure we need _SAFE_ in the flag name. Would EXPORT_OP_ASYNC_LOCK be OK with you? > unsigned long flags; > }; > > +static inline bool export_op_support_safe_async_lock(const struct export_operations *export_ops, > + const struct file_operations *f_op) > +{ > + return (export_ops->flags & EXPORT_OP_SAFE_ASYNC_LOCK) || !f_op->lock; > +} > + I'd like some cosmetic changes to this API, since this seems to be the first utility function for checking EXPORT_OP flags. - The function name is unwieldy. How about exportfs_lock_op_is_async() ? - Break up the long lines. It's OK with me if the return value type is left on a different line than the function name and parameters. - This function is globally visible, so a kdoc comment is needed. - The f_op->lock check is common to all the call sites, but it is not at all related to the export AFAICT. Can it be removed from this inline function? > extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, > int *max_len, struct inode *parent, > int flags); > -- > 2.31.1 >
On Wed, 2023-08-23 at 17:33 -0400, Alexander Aring wrote: > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > export flag to signal that the "own ->lock" implementation supports > async lock requests. The only main user is DLM that is used by GFS2 and > OCFS2 filesystem. Those implement their own lock() implementation and > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > ("nfs: block notification on fs with its own ->lock") the DLM > implementation were never updated. This patch should prepare for DLM > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > plock implementation regarding to it. > > Acked-by: Jeff Layton <jlayton@kernel.org> > Signed-off-by: Alexander Aring <aahringo@redhat.com> > --- > fs/lockd/svclock.c | 5 ++--- > fs/nfsd/nfs4state.c | 13 ++++++++++--- > include/linux/exportfs.h | 8 ++++++++ > 3 files changed, 20 insertions(+), 6 deletions(-) > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > index c43ccdf28ed9..6e3b230e8317 100644 > --- a/fs/lockd/svclock.c > +++ b/fs/lockd/svclock.c > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > struct nlm_host *host, struct nlm_lock *lock, int wait, > struct nlm_cookie *cookie, int reclaim) > { > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > struct inode *inode = nlmsvc_file_inode(file); > -#endif > struct nlm_block *block = NULL; > int error; > int mode; > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > (long long)lock->fl.fl_end, > wait); > > - if (nlmsvc_file_file(file)->f_op->lock) { > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > + nlmsvc_file_file(file)->f_op)) { > async_block = wait; > wait = 0; > } > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index 3aefbad4cc09..14ca06424ff1 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -7430,6 +7430,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > struct nfsd4_blocked_lock *nbl = NULL; > struct file_lock *file_lock = NULL; > struct file_lock *conflock = NULL; > + struct super_block *sb; > __be32 status = 0; > int lkflg; > int err; > @@ -7451,6 +7452,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > dprintk("NFSD: nfsd4_lock: permission denied!\n"); > return status; > } > + sb = cstate->current_fh.fh_dentry->d_sb; > > if (lock->lk_is_new) { > if (nfsd4_has_session(cstate)) > @@ -7502,7 +7504,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > fp = lock_stp->st_stid.sc_file; > switch (lock->lk_type) { > case NFS4_READW_LT: > - if (nfsd4_has_session(cstate)) > + if (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_READ_LT: > @@ -7514,7 +7518,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > fl_type = F_RDLCK; > break; > case NFS4_WRITEW_LT: > - if (nfsd4_has_session(cstate)) > + if (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_WRITE_LT: > @@ -7542,7 +7548,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > * for file locks), so don't attempt blocking lock notifications > * on those filesystems: > */ > - if (nf->nf_file->f_op->lock) > + if (!export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags &= ~FL_SLEEP; > > nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); > diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h > index 11fbd0ee1370..10358a93cdc1 100644 > --- a/include/linux/exportfs.h > +++ b/include/linux/exportfs.h > @@ -3,6 +3,7 @@ > #define LINUX_EXPORTFS_H 1 > > #include <linux/types.h> > +#include <linux/fs.h> > > struct dentry; > struct iattr; > @@ -224,9 +225,16 @@ struct export_operations { > atomic attribute updates > */ > #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ > +#define EXPORT_OP_SAFE_ASYNC_LOCK (0x40) /* fs can do async lock request */ > unsigned long flags; > }; > > +static inline bool export_op_support_safe_async_lock(const struct export_operations *export_ops, > + const struct file_operations *f_op) > +{ > + return (export_ops->flags & EXPORT_OP_SAFE_ASYNC_LOCK) || !f_op->lock; > +} > + > extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, > int *max_len, struct inode *parent, > int flags); Conceptually, this looks fine, but I agree with Chuck's stylistic points.
Hi, On Fri, Aug 25, 2023 at 1:21 PM Chuck Lever <chuck.lever@oracle.com> wrote: > > On Wed, Aug 23, 2023 at 05:33:46PM -0400, Alexander Aring wrote: > > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > > export flag to signal that the "own ->lock" implementation supports > > async lock requests. The only main user is DLM that is used by GFS2 and > > OCFS2 filesystem. Those implement their own lock() implementation and > > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > > ("nfs: block notification on fs with its own ->lock") the DLM > > implementation were never updated. This patch should prepare for DLM > > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > > plock implementation regarding to it. > > > > Acked-by: Jeff Layton <jlayton@kernel.org> > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > > --- > > fs/lockd/svclock.c | 5 ++--- > > fs/nfsd/nfs4state.c | 13 ++++++++++--- > > include/linux/exportfs.h | 8 ++++++++ > > 3 files changed, 20 insertions(+), 6 deletions(-) > > I'm starting to look at these. Just so you know, it's too late for > inclusion in v6.6, but I think we can get these into shape for v6.7. > ok. I base my work on [0], is this correct? > More below. > > > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > > index c43ccdf28ed9..6e3b230e8317 100644 > > --- a/fs/lockd/svclock.c > > +++ b/fs/lockd/svclock.c > > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > struct nlm_host *host, struct nlm_lock *lock, int wait, > > struct nlm_cookie *cookie, int reclaim) > > { > > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > struct inode *inode = nlmsvc_file_inode(file); > > -#endif > > struct nlm_block *block = NULL; > > int error; > > int mode; > > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > (long long)lock->fl.fl_end, > > wait); > > > > - if (nlmsvc_file_file(file)->f_op->lock) { > > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > + nlmsvc_file_file(file)->f_op)) { > > async_block = wait; > > wait = 0; > > } > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > > index 3aefbad4cc09..14ca06424ff1 100644 > > --- a/fs/nfsd/nfs4state.c > > +++ b/fs/nfsd/nfs4state.c > > @@ -7430,6 +7430,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > struct nfsd4_blocked_lock *nbl = NULL; > > struct file_lock *file_lock = NULL; > > struct file_lock *conflock = NULL; > > + struct super_block *sb; > > __be32 status = 0; > > int lkflg; > > int err; > > @@ -7451,6 +7452,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > dprintk("NFSD: nfsd4_lock: permission denied!\n"); > > return status; > > } > > + sb = cstate->current_fh.fh_dentry->d_sb; > > > > if (lock->lk_is_new) { > > if (nfsd4_has_session(cstate)) > > @@ -7502,7 +7504,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > fp = lock_stp->st_stid.sc_file; > > switch (lock->lk_type) { > > case NFS4_READW_LT: > > - if (nfsd4_has_session(cstate)) > > + if (nfsd4_has_session(cstate) || > > + export_op_support_safe_async_lock(sb->s_export_op, > > + nf->nf_file->f_op)) > > fl_flags |= FL_SLEEP; > > fallthrough; > > case NFS4_READ_LT: > > @@ -7514,7 +7518,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > fl_type = F_RDLCK; > > break; > > case NFS4_WRITEW_LT: > > - if (nfsd4_has_session(cstate)) > > + if (nfsd4_has_session(cstate) || > > + export_op_support_safe_async_lock(sb->s_export_op, > > + nf->nf_file->f_op)) > > fl_flags |= FL_SLEEP; > > fallthrough; > > case NFS4_WRITE_LT: > > @@ -7542,7 +7548,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > * for file locks), so don't attempt blocking lock notifications > > * on those filesystems: > > */ > > - if (nf->nf_file->f_op->lock) > > + if (!export_op_support_safe_async_lock(sb->s_export_op, > > + nf->nf_file->f_op)) > > fl_flags &= ~FL_SLEEP; > > > > nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); > > diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h > > index 11fbd0ee1370..10358a93cdc1 100644 > > --- a/include/linux/exportfs.h > > +++ b/include/linux/exportfs.h > > @@ -3,6 +3,7 @@ > > #define LINUX_EXPORTFS_H 1 > > > > #include <linux/types.h> > > +#include <linux/fs.h> > > > > struct dentry; > > struct iattr; > > @@ -224,9 +225,16 @@ struct export_operations { > > atomic attribute updates > > */ > > #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ > > +#define EXPORT_OP_SAFE_ASYNC_LOCK (0x40) /* fs can do async lock request */ > > We haven't been good about this recently, but the addition of new > EXPORT_OP flags need to be accompanied by updates to > Documentation/filesystems/nfs/exporting.rst. > ok. > I will see about adding documentation for other recent flags, but > please include an update to exporting.rst with this patch. > ok. > I'm not sure we need _SAFE_ in the flag name. Would > EXPORT_OP_ASYNC_LOCK be OK with you? > sure, a vfs_file_lock() can return FILE_LOCK_DEFERRED as well, even without having this export flag set. How non upstream users use it, I have no idea as it has some races. > > > unsigned long flags; > > }; > > > > +static inline bool export_op_support_safe_async_lock(const struct export_operations *export_ops, > > + const struct file_operations *f_op) > > +{ > > + return (export_ops->flags & EXPORT_OP_SAFE_ASYNC_LOCK) || !f_op->lock; > > +} > > + > > I'd like some cosmetic changes to this API, since this seems to be > the first utility function for checking EXPORT_OP flags. > > - The function name is unwieldy. How about exportfs_lock_op_is_async() ? > ok. > - Break up the long lines. It's OK with me if the return value type > is left on a different line than the function name and parameters. > ok. > - This function is globally visible, so a kdoc comment is needed. > ok. > - The f_op->lock check is common to all the call sites, but it is > not at all related to the export AFAICT. Can it be removed from > this inline function? > This flag implies it makes only sense if the filesystem has its own lock() implementation, if it doesn't have that I guess the core fs functions for local file locking are being used. I guess it can be removed, but it should not be used when there is no own ->lock() implementation, at least not now until somebody might update the fs core functionality for local file locking to handle blocking lock requests asynchronously. - Alex [0] https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/log/?h=nfsd-next
On Wed, Aug 30, 2023 at 08:32:43AM -0400, Alexander Aring wrote: > Hi, > > On Fri, Aug 25, 2023 at 1:21 PM Chuck Lever <chuck.lever@oracle.com> wrote: > > > > On Wed, Aug 23, 2023 at 05:33:46PM -0400, Alexander Aring wrote: > > > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > > > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > > > export flag to signal that the "own ->lock" implementation supports > > > async lock requests. The only main user is DLM that is used by GFS2 and > > > OCFS2 filesystem. Those implement their own lock() implementation and > > > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > > > ("nfs: block notification on fs with its own ->lock") the DLM > > > implementation were never updated. This patch should prepare for DLM > > > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > > > plock implementation regarding to it. > > > > > > Acked-by: Jeff Layton <jlayton@kernel.org> > > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > > > --- > > > fs/lockd/svclock.c | 5 ++--- > > > fs/nfsd/nfs4state.c | 13 ++++++++++--- > > > include/linux/exportfs.h | 8 ++++++++ > > > 3 files changed, 20 insertions(+), 6 deletions(-) > > > > I'm starting to look at these. Just so you know, it's too late for > > inclusion in v6.6, but I think we can get these into shape for v6.7. > > > > ok. I base my work on [0], is this correct? Correct. Fyi, that is currently what is pending for v6.6. When the merge window closes, it will jump to what will go into v6.7. > > - The f_op->lock check is common to all the call sites, but it is > > not at all related to the export AFAICT. Can it be removed from > > this inline function? > > > > This flag implies it makes only sense if the filesystem has its own > lock() implementation, if it doesn't have that I guess the core fs > functions for local file locking are being used. > I guess it can be removed, but it should not be used when there is no > own ->lock() implementation, at least not now until somebody might > update the fs core functionality for local file locking to handle > blocking lock requests asynchronously. Can that be handled with a remark in the documenting comment? > [0] https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/log/?h=nfsd-next
On 23 Aug 2023, at 17:33, Alexander Aring wrote: > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > export flag to signal that the "own ->lock" implementation supports > async lock requests. The only main user is DLM that is used by GFS2 and > OCFS2 filesystem. Those implement their own lock() implementation and > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > ("nfs: block notification on fs with its own ->lock") the DLM > implementation were never updated. This patch should prepare for DLM > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > plock implementation regarding to it. > > Acked-by: Jeff Layton <jlayton@kernel.org> > Signed-off-by: Alexander Aring <aahringo@redhat.com> > --- > fs/lockd/svclock.c | 5 ++--- > fs/nfsd/nfs4state.c | 13 ++++++++++--- > include/linux/exportfs.h | 8 ++++++++ > 3 files changed, 20 insertions(+), 6 deletions(-) > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > index c43ccdf28ed9..6e3b230e8317 100644 > --- a/fs/lockd/svclock.c > +++ b/fs/lockd/svclock.c > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > struct nlm_host *host, struct nlm_lock *lock, int wait, > struct nlm_cookie *cookie, int reclaim) > { > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > struct inode *inode = nlmsvc_file_inode(file); > -#endif > struct nlm_block *block = NULL; > int error; > int mode; > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > (long long)lock->fl.fl_end, > wait); > > - if (nlmsvc_file_file(file)->f_op->lock) { > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > + nlmsvc_file_file(file)->f_op)) { ... but don't most filesystem use VFS' posix_lock_file(), which does the right thing? I think this patch has broken async lock callbacks for NLM for all the other filesystems that just use posix_lock_file(). Maybe I'm missing something, but why was that necessary? Ben
On Tue, 2024-09-10 at 10:18 -0400, Benjamin Coddington wrote: > On 23 Aug 2023, at 17:33, Alexander Aring wrote: > > > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > > export flag to signal that the "own ->lock" implementation supports > > async lock requests. The only main user is DLM that is used by GFS2 and > > OCFS2 filesystem. Those implement their own lock() implementation and > > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > > ("nfs: block notification on fs with its own ->lock") the DLM > > implementation were never updated. This patch should prepare for DLM > > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > > plock implementation regarding to it. > > > > Acked-by: Jeff Layton <jlayton@kernel.org> > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > > --- > > fs/lockd/svclock.c | 5 ++--- > > fs/nfsd/nfs4state.c | 13 ++++++++++--- > > include/linux/exportfs.h | 8 ++++++++ > > 3 files changed, 20 insertions(+), 6 deletions(-) > > > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > > index c43ccdf28ed9..6e3b230e8317 100644 > > --- a/fs/lockd/svclock.c > > +++ b/fs/lockd/svclock.c > > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > struct nlm_host *host, struct nlm_lock *lock, int wait, > > struct nlm_cookie *cookie, int reclaim) > > { > > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > struct inode *inode = nlmsvc_file_inode(file); > > -#endif > > struct nlm_block *block = NULL; > > int error; > > int mode; > > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > (long long)lock->fl.fl_end, > > wait); > > > > - if (nlmsvc_file_file(file)->f_op->lock) { > > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > + nlmsvc_file_file(file)->f_op)) { > > ... but don't most filesystem use VFS' posix_lock_file(), which does the > right thing? I think this patch has broken async lock callbacks for NLM for > all the other filesystems that just use posix_lock_file(). > > Maybe I'm missing something, but why was that necessary? > Good catch. Yeah, I think that probably should have been an && condition. IOW: if (nlmsvc_file_file(file)->f_op->lock && !export_op_support_safe_async_lock(inode->i_sb->s_export_op, Alex, thoughts?
On 10 Sep 2024, at 11:45, Jeff Layton wrote: > On Tue, 2024-09-10 at 10:18 -0400, Benjamin Coddington wrote: >> On 23 Aug 2023, at 17:33, Alexander Aring wrote: >> >>> This patch reverts mostly commit 40595cdc93ed ("nfs: block notification >>> on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK >>> export flag to signal that the "own ->lock" implementation supports >>> async lock requests. The only main user is DLM that is used by GFS2 and >>> OCFS2 filesystem. Those implement their own lock() implementation and >>> return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed >>> ("nfs: block notification on fs with its own ->lock") the DLM >>> implementation were never updated. This patch should prepare for DLM >>> to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM >>> plock implementation regarding to it. >>> >>> Acked-by: Jeff Layton <jlayton@kernel.org> >>> Signed-off-by: Alexander Aring <aahringo@redhat.com> >>> --- >>> fs/lockd/svclock.c | 5 ++--- >>> fs/nfsd/nfs4state.c | 13 ++++++++++--- >>> include/linux/exportfs.h | 8 ++++++++ >>> 3 files changed, 20 insertions(+), 6 deletions(-) >>> >>> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c >>> index c43ccdf28ed9..6e3b230e8317 100644 >>> --- a/fs/lockd/svclock.c >>> +++ b/fs/lockd/svclock.c >>> @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, >>> struct nlm_host *host, struct nlm_lock *lock, int wait, >>> struct nlm_cookie *cookie, int reclaim) >>> { >>> -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) >>> struct inode *inode = nlmsvc_file_inode(file); >>> -#endif >>> struct nlm_block *block = NULL; >>> int error; >>> int mode; >>> @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, >>> (long long)lock->fl.fl_end, >>> wait); >>> >>> - if (nlmsvc_file_file(file)->f_op->lock) { >>> + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, >>> + nlmsvc_file_file(file)->f_op)) { >> >> ... but don't most filesystem use VFS' posix_lock_file(), which does the >> right thing? I think this patch has broken async lock callbacks for NLM for >> all the other filesystems that just use posix_lock_file(). >> >> Maybe I'm missing something, but why was that necessary? >> > > Good catch. Yeah, I think that probably should have been an && > condition. IOW: > > if (nlmsvc_file_file(file)->f_op->lock && > !export_op_support_safe_async_lock(inode->i_sb->s_export_op, > Ah Jeff, thanks for confirming - there's been a bunch of changes in there that made me uncertain. I can send a patch for this, I'd like to rename export_op_support_safe_async_lock to something like fs_can_defer_lock (suggestions) and put the test in there. Ben
Hi, On Tue, Sep 10, 2024 at 11:45 AM Jeff Layton <jlayton@kernel.org> wrote: > > On Tue, 2024-09-10 at 10:18 -0400, Benjamin Coddington wrote: > > On 23 Aug 2023, at 17:33, Alexander Aring wrote: > > > > > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > > > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > > > export flag to signal that the "own ->lock" implementation supports > > > async lock requests. The only main user is DLM that is used by GFS2 and > > > OCFS2 filesystem. Those implement their own lock() implementation and > > > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > > > ("nfs: block notification on fs with its own ->lock") the DLM > > > implementation were never updated. This patch should prepare for DLM > > > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > > > plock implementation regarding to it. > > > > > > Acked-by: Jeff Layton <jlayton@kernel.org> > > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > > > --- > > > fs/lockd/svclock.c | 5 ++--- > > > fs/nfsd/nfs4state.c | 13 ++++++++++--- > > > include/linux/exportfs.h | 8 ++++++++ > > > 3 files changed, 20 insertions(+), 6 deletions(-) > > > > > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > > > index c43ccdf28ed9..6e3b230e8317 100644 > > > --- a/fs/lockd/svclock.c > > > +++ b/fs/lockd/svclock.c > > > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > > struct nlm_host *host, struct nlm_lock *lock, int wait, > > > struct nlm_cookie *cookie, int reclaim) > > > { > > > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > > struct inode *inode = nlmsvc_file_inode(file); > > > -#endif > > > struct nlm_block *block = NULL; > > > int error; > > > int mode; > > > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > > (long long)lock->fl.fl_end, > > > wait); > > > > > > - if (nlmsvc_file_file(file)->f_op->lock) { > > > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > > + nlmsvc_file_file(file)->f_op)) { > > > > ... but don't most filesystem use VFS' posix_lock_file(), which does the > > right thing? I think this patch has broken async lock callbacks for NLM for > > all the other filesystems that just use posix_lock_file(). > > > > Maybe I'm missing something, but why was that necessary? > > > > Good catch. Yeah, I think that probably should have been an && > condition. IOW: > > if (nlmsvc_file_file(file)->f_op->lock && > !export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > Alex, thoughts? The question is here if we ever want that posix_lock_file() receives a posix lock that has flc_flags and the FL_SLEEP set. As mentioned, may "posix_lock_file()" can just deal with it and will not block? This patch indeed broke it as posix_lock_file() will never see a lock request with FL_SLEEP set, but I remembered that nfs is only polling locks and "probably" never set FL_SLEEP? Thanks. - Alex
Hi, On Tue, Sep 10, 2024 at 12:56 PM Benjamin Coddington <bcodding@redhat.com> wrote: > > On 10 Sep 2024, at 11:45, Jeff Layton wrote: > > > On Tue, 2024-09-10 at 10:18 -0400, Benjamin Coddington wrote: > >> On 23 Aug 2023, at 17:33, Alexander Aring wrote: > >> > >>> This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > >>> on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > >>> export flag to signal that the "own ->lock" implementation supports > >>> async lock requests. The only main user is DLM that is used by GFS2 and > >>> OCFS2 filesystem. Those implement their own lock() implementation and > >>> return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > >>> ("nfs: block notification on fs with its own ->lock") the DLM > >>> implementation were never updated. This patch should prepare for DLM > >>> to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > >>> plock implementation regarding to it. > >>> > >>> Acked-by: Jeff Layton <jlayton@kernel.org> > >>> Signed-off-by: Alexander Aring <aahringo@redhat.com> > >>> --- > >>> fs/lockd/svclock.c | 5 ++--- > >>> fs/nfsd/nfs4state.c | 13 ++++++++++--- > >>> include/linux/exportfs.h | 8 ++++++++ > >>> 3 files changed, 20 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > >>> index c43ccdf28ed9..6e3b230e8317 100644 > >>> --- a/fs/lockd/svclock.c > >>> +++ b/fs/lockd/svclock.c > >>> @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > >>> struct nlm_host *host, struct nlm_lock *lock, int wait, > >>> struct nlm_cookie *cookie, int reclaim) > >>> { > >>> -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > >>> struct inode *inode = nlmsvc_file_inode(file); > >>> -#endif > >>> struct nlm_block *block = NULL; > >>> int error; > >>> int mode; > >>> @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > >>> (long long)lock->fl.fl_end, > >>> wait); > >>> > >>> - if (nlmsvc_file_file(file)->f_op->lock) { > >>> + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > >>> + nlmsvc_file_file(file)->f_op)) { > >> > >> ... but don't most filesystem use VFS' posix_lock_file(), which does the > >> right thing? I think this patch has broken async lock callbacks for NLM for > >> all the other filesystems that just use posix_lock_file(). > >> > >> Maybe I'm missing something, but why was that necessary? > >> > > > > Good catch. Yeah, I think that probably should have been an && > > condition. IOW: > > > > if (nlmsvc_file_file(file)->f_op->lock && > > !export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > > > Ah Jeff, thanks for confirming - there's been a bunch of changes in there that > made me uncertain. I can send a patch for this, I'd like to rename > export_op_support_safe_async_lock to something like fs_can_defer_lock > (suggestions) and put the test in there. go ahead with the name change. About the uncertainty the other changes, except this one mentioned above here in the reply, was a revert of commit 40595cdc93ed ("block notification on fs with its own ->lock") that had removed a similar flag to in kind of a reverse logic. The flag means something that the commit message says "... filesystems with "good" ->lock methods to support blocking lock notifications.". - Alex
On Tue, 2024-09-10 at 12:56 -0400, Benjamin Coddington wrote: > On 10 Sep 2024, at 11:45, Jeff Layton wrote: > > > On Tue, 2024-09-10 at 10:18 -0400, Benjamin Coddington wrote: > > > On 23 Aug 2023, at 17:33, Alexander Aring wrote: > > > > > > > This patch reverts mostly commit 40595cdc93ed ("nfs: block notification > > > > on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK > > > > export flag to signal that the "own ->lock" implementation supports > > > > async lock requests. The only main user is DLM that is used by GFS2 and > > > > OCFS2 filesystem. Those implement their own lock() implementation and > > > > return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed > > > > ("nfs: block notification on fs with its own ->lock") the DLM > > > > implementation were never updated. This patch should prepare for DLM > > > > to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM > > > > plock implementation regarding to it. > > > > > > > > Acked-by: Jeff Layton <jlayton@kernel.org> > > > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > > > > --- > > > > fs/lockd/svclock.c | 5 ++--- > > > > fs/nfsd/nfs4state.c | 13 ++++++++++--- > > > > include/linux/exportfs.h | 8 ++++++++ > > > > 3 files changed, 20 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > > > > index c43ccdf28ed9..6e3b230e8317 100644 > > > > --- a/fs/lockd/svclock.c > > > > +++ b/fs/lockd/svclock.c > > > > @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > > > struct nlm_host *host, struct nlm_lock *lock, int wait, > > > > struct nlm_cookie *cookie, int reclaim) > > > > { > > > > -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > > > struct inode *inode = nlmsvc_file_inode(file); > > > > -#endif > > > > struct nlm_block *block = NULL; > > > > int error; > > > > int mode; > > > > @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > > > > (long long)lock->fl.fl_end, > > > > wait); > > > > > > > > - if (nlmsvc_file_file(file)->f_op->lock) { > > > > + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > > > + nlmsvc_file_file(file)->f_op)) { > > > > > > ... but don't most filesystem use VFS' posix_lock_file(), which does the > > > right thing? I think this patch has broken async lock callbacks for NLM for > > > all the other filesystems that just use posix_lock_file(). > > > > > > Maybe I'm missing something, but why was that necessary? > > > > > > > Good catch. Yeah, I think that probably should have been an && > > condition. IOW: > > > > if (nlmsvc_file_file(file)->f_op->lock && > > !export_op_support_safe_async_lock(inode->i_sb->s_export_op, > > > > Ah Jeff, thanks for confirming - there's been a bunch of changes in there that > made me uncertain. I can send a patch for this, I'd like to rename > export_op_support_safe_async_lock to something like fs_can_defer_lock > (suggestions) and put the test in there. Actually, I take it back. The only callers that set export_op_support_safe_async_lock have ->lock as non-NULL, so that won't change anything, in practice.
On 11 Sep 2024, at 9:24, Jeff Layton wrote: > On Tue, 2024-09-10 at 12:56 -0400, Benjamin Coddington wrote: >> On 10 Sep 2024, at 11:45, Jeff Layton wrote: >> >>> Good catch. Yeah, I think that probably should have been an && >>> condition. IOW: >>> >>> if (nlmsvc_file_file(file)->f_op->lock && >>> !export_op_support_safe_async_lock(inode->i_sb->s_export_op, >>> >> >> Ah Jeff, thanks for confirming - there's been a bunch of changes in there that >> made me uncertain. I can send a patch for this, I'd like to rename >> export_op_support_safe_async_lock to something like fs_can_defer_lock >> (suggestions) and put the test in there. > > Actually, I take it back. The only callers that set > export_op_support_safe_async_lock have ->lock as non-NULL, so that > won't change anything, in practice. *nod* In trying to conjoin the export flag test with the f_op->lock test, I'm just making a huge mess of layering violations. The changes for NFSD are terrible. Seems like we want an FOP_ flag for this, I might ask for one. Wouldn't other users like FUSE be interested? Ben
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index c43ccdf28ed9..6e3b230e8317 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, struct nlm_host *host, struct nlm_lock *lock, int wait, struct nlm_cookie *cookie, int reclaim) { -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) struct inode *inode = nlmsvc_file_inode(file); -#endif struct nlm_block *block = NULL; int error; int mode; @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, (long long)lock->fl.fl_end, wait); - if (nlmsvc_file_file(file)->f_op->lock) { + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op, + nlmsvc_file_file(file)->f_op)) { async_block = wait; wait = 0; } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 3aefbad4cc09..14ca06424ff1 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -7430,6 +7430,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_blocked_lock *nbl = NULL; struct file_lock *file_lock = NULL; struct file_lock *conflock = NULL; + struct super_block *sb; __be32 status = 0; int lkflg; int err; @@ -7451,6 +7452,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, dprintk("NFSD: nfsd4_lock: permission denied!\n"); return status; } + sb = cstate->current_fh.fh_dentry->d_sb; if (lock->lk_is_new) { if (nfsd4_has_session(cstate)) @@ -7502,7 +7504,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, fp = lock_stp->st_stid.sc_file; switch (lock->lk_type) { case NFS4_READW_LT: - if (nfsd4_has_session(cstate)) + if (nfsd4_has_session(cstate) || + export_op_support_safe_async_lock(sb->s_export_op, + nf->nf_file->f_op)) fl_flags |= FL_SLEEP; fallthrough; case NFS4_READ_LT: @@ -7514,7 +7518,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, fl_type = F_RDLCK; break; case NFS4_WRITEW_LT: - if (nfsd4_has_session(cstate)) + if (nfsd4_has_session(cstate) || + export_op_support_safe_async_lock(sb->s_export_op, + nf->nf_file->f_op)) fl_flags |= FL_SLEEP; fallthrough; case NFS4_WRITE_LT: @@ -7542,7 +7548,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, * for file locks), so don't attempt blocking lock notifications * on those filesystems: */ - if (nf->nf_file->f_op->lock) + if (!export_op_support_safe_async_lock(sb->s_export_op, + nf->nf_file->f_op)) fl_flags &= ~FL_SLEEP; nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 11fbd0ee1370..10358a93cdc1 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -3,6 +3,7 @@ #define LINUX_EXPORTFS_H 1 #include <linux/types.h> +#include <linux/fs.h> struct dentry; struct iattr; @@ -224,9 +225,16 @@ struct export_operations { atomic attribute updates */ #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ +#define EXPORT_OP_SAFE_ASYNC_LOCK (0x40) /* fs can do async lock request */ unsigned long flags; }; +static inline bool export_op_support_safe_async_lock(const struct export_operations *export_ops, + const struct file_operations *f_op) +{ + return (export_ops->flags & EXPORT_OP_SAFE_ASYNC_LOCK) || !f_op->lock; +} + extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, int *max_len, struct inode *parent, int flags);
This patch reverts mostly commit 40595cdc93ed ("nfs: block notification on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK export flag to signal that the "own ->lock" implementation supports async lock requests. The only main user is DLM that is used by GFS2 and OCFS2 filesystem. Those implement their own lock() implementation and return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed ("nfs: block notification on fs with its own ->lock") the DLM implementation were never updated. This patch should prepare for DLM to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM plock implementation regarding to it. Acked-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Alexander Aring <aahringo@redhat.com> --- fs/lockd/svclock.c | 5 ++--- fs/nfsd/nfs4state.c | 13 ++++++++++--- include/linux/exportfs.h | 8 ++++++++ 3 files changed, 20 insertions(+), 6 deletions(-)