| Message ID | 20210129192629.GC8033@fieldses.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2,v2] nfs: use change attribute for NFS re-exports | expand |
Hi Bruce- > On Jan 29, 2021, at 2:26 PM, J. Bruce Fields <bfields@fieldses.org> wrote: > > From: "J. Bruce Fields" <bfields@redhat.com> > > When exporting NFS, we may as well use the real change attribute > returned by the original server instead of faking up a change attribute > from the ctime. > > Note we can't do that by setting I_VERSION--that would also turn on the > logic in iversion.h which treats the lower bit specially, and that > doesn't make sense for NFS. > > So instead we define a new export operation for filesystems like NFS > that want to manage the change attribute themselves. > > Signed-off-by: J. Bruce Fields <bfields@redhat.com> These two patches have replaced the v1 patches from last week in the for-next branch at git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git These are included provisionally while review and further testing is ongoing. > --- > fs/nfs/export.c | 18 ++++++++++++++++++ > fs/nfsd/nfsfh.h | 5 ++++- > include/linux/exportfs.h | 1 + > 3 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/fs/nfs/export.c b/fs/nfs/export.c > index 7412bb164fa7..f2b34cfe286c 100644 > --- a/fs/nfs/export.c > +++ b/fs/nfs/export.c > @@ -167,10 +167,28 @@ nfs_get_parent(struct dentry *dentry) > return parent; > } > > +static u64 nfs_fetch_iversion(struct inode *inode) > +{ > + struct nfs_server *server = NFS_SERVER(inode); > + > + /* Is this the right call?: */ > + nfs_revalidate_inode(server, inode); > + /* > + * Also, note we're ignoring any returned error. That seems to be > + * the practice for cache consistency information elsewhere in > + * the server, but I'm not sure why. > + */ > + if (server->nfs_client->rpc_ops->version >= 4) > + return inode_peek_iversion_raw(inode); > + else > + return time_to_chattr(&inode->i_ctime); > +} > + > const struct export_operations nfs_export_ops = { > .encode_fh = nfs_encode_fh, > .fh_to_dentry = nfs_fh_to_dentry, > .get_parent = nfs_get_parent, > + .fetch_iversion = nfs_fetch_iversion, > .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK| > EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS| > EXPORT_OP_NOATOMIC_ATTR, > diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h > index cb20c2cd3469..f58933519f38 100644 > --- a/fs/nfsd/nfsfh.h > +++ b/fs/nfsd/nfsfh.h > @@ -12,6 +12,7 @@ > #include <linux/sunrpc/svc.h> > #include <uapi/linux/nfsd/nfsfh.h> > #include <linux/iversion.h> > +#include <linux/exportfs.h> > > static inline __u32 ino_t_to_u32(ino_t ino) > { > @@ -264,7 +265,9 @@ fh_clear_wcc(struct svc_fh *fhp) > static inline u64 nfsd4_change_attribute(struct kstat *stat, > struct inode *inode) > { > - if (IS_I_VERSION(inode)) { > + if (inode->i_sb->s_export_op->fetch_iversion) > + return inode->i_sb->s_export_op->fetch_iversion(inode); > + else if (IS_I_VERSION(inode)) { > u64 chattr; > > chattr = stat->ctime.tv_sec; > diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h > index 9f4d4bcbf251..fe848901fcc3 100644 > --- a/include/linux/exportfs.h > +++ b/include/linux/exportfs.h > @@ -213,6 +213,7 @@ struct export_operations { > bool write, u32 *device_generation); > int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, > int nr_iomaps, struct iattr *iattr); > + u64 (*fetch_iversion)(struct inode *); > #define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ > #define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ > #define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */ > -- > 2.29.2 > -- Chuck Lever
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/nfs/export.c b/fs/nfs/export.c index 7412bb164fa7..f2b34cfe286c 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -167,10 +167,28 @@ nfs_get_parent(struct dentry *dentry) return parent; } +static u64 nfs_fetch_iversion(struct inode *inode) +{ + struct nfs_server *server = NFS_SERVER(inode); + + /* Is this the right call?: */ + nfs_revalidate_inode(server, inode); + /* + * Also, note we're ignoring any returned error. That seems to be + * the practice for cache consistency information elsewhere in + * the server, but I'm not sure why. + */ + if (server->nfs_client->rpc_ops->version >= 4) + return inode_peek_iversion_raw(inode); + else + return time_to_chattr(&inode->i_ctime); +} + const struct export_operations nfs_export_ops = { .encode_fh = nfs_encode_fh, .fh_to_dentry = nfs_fh_to_dentry, .get_parent = nfs_get_parent, + .fetch_iversion = nfs_fetch_iversion, .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK| EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS| EXPORT_OP_NOATOMIC_ATTR, diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h index cb20c2cd3469..f58933519f38 100644 --- a/fs/nfsd/nfsfh.h +++ b/fs/nfsd/nfsfh.h @@ -12,6 +12,7 @@ #include <linux/sunrpc/svc.h> #include <uapi/linux/nfsd/nfsfh.h> #include <linux/iversion.h> +#include <linux/exportfs.h> static inline __u32 ino_t_to_u32(ino_t ino) { @@ -264,7 +265,9 @@ fh_clear_wcc(struct svc_fh *fhp) static inline u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode) { - if (IS_I_VERSION(inode)) { + if (inode->i_sb->s_export_op->fetch_iversion) + return inode->i_sb->s_export_op->fetch_iversion(inode); + else if (IS_I_VERSION(inode)) { u64 chattr; chattr = stat->ctime.tv_sec; diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 9f4d4bcbf251..fe848901fcc3 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -213,6 +213,7 @@ struct export_operations { bool write, u32 *device_generation); int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, int nr_iomaps, struct iattr *iattr); + u64 (*fetch_iversion)(struct inode *); #define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ #define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ #define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */