From c654b8a9cba6002aad1c01919e4928a79a4a6dcf Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Thu, 16 Apr 2009 17:33:25 -0400 Subject: nfsd: support ext4 i_version ext4 supports a real NFSv4 change attribute, which is bumped whenever the ctime would be updated, including times when two updates arrive within a jiffy of each other. (Note that although ext4 has space for nanosecond-precision ctime, the real resolution is lower: it actually uses jiffies as the time-source.) This ensures clients will invalidate their caches when they need to. There is some fear that keeping the i_version up-to-date could have performance drawbacks, so for now it's turned on only by a mount option. We hope to do something better eventually. Signed-off-by: J. Bruce Fields Cc: Theodore Tso --- include/linux/nfsd/nfsfh.h | 7 +++++++ include/linux/nfsd/xdr4.h | 17 +++++++++++++---- 2 files changed, 20 insertions(+), 4 deletions(-) (limited to 'include/linux/nfsd') diff --git a/include/linux/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h index afa19016c4a..8f641c90845 100644 --- a/include/linux/nfsd/nfsfh.h +++ b/include/linux/nfsd/nfsfh.h @@ -151,9 +151,15 @@ typedef struct svc_fh { __u64 fh_pre_size; /* size before operation */ struct timespec fh_pre_mtime; /* mtime before oper */ struct timespec fh_pre_ctime; /* ctime before oper */ + /* + * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode) + * to find out if it is valid. + */ + u64 fh_pre_change; /* Post-op attributes saved in fh_unlock */ struct kstat fh_post_attr; /* full attrs after operation */ + u64 fh_post_change; /* nfsv4 change; see above */ #endif /* CONFIG_NFSD_V3 */ } svc_fh; @@ -298,6 +304,7 @@ fill_pre_wcc(struct svc_fh *fhp) fhp->fh_pre_mtime = inode->i_mtime; fhp->fh_pre_ctime = inode->i_ctime; fhp->fh_pre_size = inode->i_size; + fhp->fh_pre_change = inode->i_version; fhp->fh_pre_saved = 1; } } diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h index f80d6013fdc..d0f050f01ec 100644 --- a/include/linux/nfsd/xdr4.h +++ b/include/linux/nfsd/xdr4.h @@ -64,10 +64,13 @@ static inline bool nfsd4_has_session(struct nfsd4_compound_state *cs) struct nfsd4_change_info { u32 atomic; + bool change_supported; u32 before_ctime_sec; u32 before_ctime_nsec; + u64 before_change; u32 after_ctime_sec; u32 after_ctime_nsec; + u64 after_change; }; struct nfsd4_access { @@ -503,10 +506,16 @@ set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp) { BUG_ON(!fhp->fh_pre_saved || !fhp->fh_post_saved); cinfo->atomic = 1; - cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec; - cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec; - cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec; - cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec; + cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode); + if (cinfo->change_supported) { + cinfo->before_change = fhp->fh_pre_change; + cinfo->after_change = fhp->fh_post_change; + } else { + cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec; + cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec; + cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec; + cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec; + } } int nfs4svc_encode_voidres(struct svc_rqst *, __be32 *, void *); -- cgit v1.2.3