From c654b8a9cba6002aad1c01919e4928a79a4a6dcf Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Thu, 16 Apr 2009 17:33:25 -0400 Subject: [PATCH] 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 --- fs/nfsd/nfs3xdr.c | 1 + fs/nfsd/nfs4xdr.c | 63 ++++++++++++++++++++++++++++++---------------- include/linux/nfsd/nfsfh.h | 7 ++++++ include/linux/nfsd/xdr4.h | 17 ++++++++++--- 4 files changed, 63 insertions(+), 25 deletions(-) diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 17d0dd9..01d4ec1 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -272,6 +272,7 @@ void fill_post_wcc(struct svc_fh *fhp) err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &fhp->fh_post_attr); + fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version; if (err) fhp->fh_post_saved = 0; else diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 4a71fcd..12d36a7 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1490,13 +1490,41 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) memcpy(p, ptr, nbytes); \ p += XDR_QUADLEN(nbytes); \ }} while (0) -#define WRITECINFO(c) do { \ - *p++ = htonl(c.atomic); \ - *p++ = htonl(c.before_ctime_sec); \ - *p++ = htonl(c.before_ctime_nsec); \ - *p++ = htonl(c.after_ctime_sec); \ - *p++ = htonl(c.after_ctime_nsec); \ -} while (0) + +static void write32(__be32 **p, u32 n) +{ + *(*p)++ = n; +} + +static void write64(__be32 **p, u64 n) +{ + write32(p, (u32)(n >> 32)); + write32(p, (u32)n); +} + +static void write_change(__be32 **p, struct kstat *stat, struct inode *inode) +{ + if (IS_I_VERSION(inode)) { + write64(p, inode->i_version); + } else { + write32(p, stat->ctime.tv_sec); + write32(p, stat->ctime.tv_nsec); + } +} + +static void write_cinfo(__be32 **p, struct nfsd4_change_info *c) +{ + write32(p, c->atomic); + if (c->change_supported) { + write64(p, c->before_change); + write64(p, c->after_change); + } else { + write32(p, c->before_ctime_sec); + write32(p, c->before_ctime_nsec); + write32(p, c->after_ctime_sec); + write32(p, c->after_ctime_nsec); + } +} #define RESERVE_SPACE(nbytes) do { \ p = resp->p; \ @@ -1849,16 +1877,9 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, WRITE32(NFS4_FH_PERSISTENT|NFS4_FH_VOL_RENAME); } if (bmval0 & FATTR4_WORD0_CHANGE) { - /* - * Note: This _must_ be consistent with the scheme for writing - * change_info, so any changes made here must be reflected there - * as well. (See xdr4.h:set_change_info() and the WRITECINFO() - * macro above.) - */ if ((buflen -= 8) < 0) goto out_resource; - WRITE32(stat.ctime.tv_sec); - WRITE32(stat.ctime.tv_nsec); + write_change(&p, &stat, dentry->d_inode); } if (bmval0 & FATTR4_WORD0_SIZE) { if ((buflen -= 8) < 0) @@ -2364,7 +2385,7 @@ nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_ if (!nfserr) { RESERVE_SPACE(32); - WRITECINFO(create->cr_cinfo); + write_cinfo(&p, &create->cr_cinfo); WRITE32(2); WRITE32(create->cr_bmval[0]); WRITE32(create->cr_bmval[1]); @@ -2475,7 +2496,7 @@ nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_li if (!nfserr) { RESERVE_SPACE(20); - WRITECINFO(link->li_cinfo); + write_cinfo(&p, &link->li_cinfo); ADJUST_ARGS(); } return nfserr; @@ -2493,7 +2514,7 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_op nfsd4_encode_stateid(resp, &open->op_stateid); RESERVE_SPACE(40); - WRITECINFO(open->op_cinfo); + write_cinfo(&p, &open->op_cinfo); WRITE32(open->op_rflags); WRITE32(2); WRITE32(open->op_bmval[0]); @@ -2771,7 +2792,7 @@ nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_ if (!nfserr) { RESERVE_SPACE(20); - WRITECINFO(remove->rm_cinfo); + write_cinfo(&p, &remove->rm_cinfo); ADJUST_ARGS(); } return nfserr; @@ -2784,8 +2805,8 @@ nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_ if (!nfserr) { RESERVE_SPACE(40); - WRITECINFO(rename->rn_sinfo); - WRITECINFO(rename->rn_tinfo); + write_cinfo(&p, &rename->rn_sinfo); + write_cinfo(&p, &rename->rn_tinfo); ADJUST_ARGS(); } return nfserr; diff --git a/include/linux/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h index afa1901..8f641c9 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 f80d601..d0f050f 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 *); -- 1.8.2.3