NFS: Optimise inode attribute cache updates Allow nfs_refresh_inode() also to update attributes on the inode if the RPC call was sent after the last call to nfs_update_inode(). Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 54 +++++++++++++++++++++++++++++++++++------------- fs/nfs/nfs2xdr.c | 1 fs/nfs/nfs3xdr.c | 1 fs/nfs/nfs4xdr.c | 4 --- include/linux/nfs_fs.h | 2 + include/linux/nfs_xdr.h | 2 - 6 files changed, 44 insertions(+), 20 deletions(-) Index: linux-2.6/include/linux/nfs_fs.h =================================================================== --- linux-2.6.orig/include/linux/nfs_fs.h +++ linux-2.6/include/linux/nfs_fs.h @@ -141,6 +141,7 @@ struct nfs_inode { unsigned long attrtimeo_timestamp; __u64 change_attr; /* v4 only */ + unsigned long last_updated; /* "Generation counter" for the attribute cache. This is * bumped whenever we update the metadata on the * server. @@ -319,6 +320,7 @@ extern u32 root_nfs_parse_addr(char *nam static inline void nfs_fattr_init(struct nfs_fattr *fattr) { fattr->valid = 0; + fattr->time_start = jiffies; } /* Index: linux-2.6/include/linux/nfs_xdr.h =================================================================== --- linux-2.6.orig/include/linux/nfs_xdr.h +++ linux-2.6/include/linux/nfs_xdr.h @@ -41,7 +41,7 @@ struct nfs_fattr { __u32 bitmap[2]; /* NFSv4 returned attribute bitmap */ __u64 change_attr; /* NFSv4 change attribute */ __u64 pre_change_attr;/* pre-op NFSv4 change attribute */ - unsigned long timestamp; + unsigned long time_start; }; #define NFS_ATTR_WCC 0x0001 /* pre-op WCC data */ Index: linux-2.6/fs/nfs/inode.c =================================================================== --- linux-2.6.orig/fs/nfs/inode.c +++ linux-2.6/fs/nfs/inode.c @@ -785,7 +785,8 @@ nfs_fhget(struct super_block *sb, struct else init_special_inode(inode, inode->i_mode, fattr->rdev); - nfsi->read_cache_jiffies = fattr->timestamp; + nfsi->read_cache_jiffies = fattr->time_start; + nfsi->last_updated = jiffies; inode->i_atime = fattr->atime; inode->i_mtime = fattr->mtime; inode->i_ctime = fattr->ctime; @@ -1120,14 +1121,15 @@ __nfs_revalidate_inode(struct nfs_server goto out; } + spin_lock(&inode->i_lock); status = nfs_update_inode(inode, &fattr, verifier); if (status) { + spin_unlock(&inode->i_lock); dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n", inode->i_sb->s_id, (long long)NFS_FILEID(inode), status); goto out; } - spin_lock(&inode->i_lock); cache_validity = nfsi->cache_validity; nfsi->cache_validity &= ~NFS_INO_REVAL_PAGECACHE; @@ -1247,7 +1249,7 @@ void nfs_end_data_update(struct inode *i } /** - * nfs_refresh_inode - verify consistency of the inode attribute cache + * nfs_check_inode_attributes - verify consistency of the inode attribute cache * @inode - pointer to inode * @fattr - updated attributes * @@ -1255,13 +1257,12 @@ void nfs_end_data_update(struct inode *i * so that fattr carries weak cache consistency data, then it may * also update the ctime/mtime/change_attribute. */ -int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) +static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr) { struct nfs_inode *nfsi = NFS_I(inode); loff_t cur_size, new_isize; int data_unstable; - spin_lock(&inode->i_lock); /* Are we in the process of updating data on the server? */ data_unstable = nfs_caches_unstable(inode); @@ -1325,11 +1326,40 @@ int nfs_refresh_inode(struct inode *inod if (!timespec_equal(&inode->i_atime, &fattr->atime)) nfsi->cache_validity |= NFS_INO_INVALID_ATIME; - nfsi->read_cache_jiffies = fattr->timestamp; - spin_unlock(&inode->i_lock); + nfsi->read_cache_jiffies = fattr->time_start; return 0; } +/** + * nfs_refresh_inode - try to update the inode attribute cache + * @inode - pointer to inode + * @fattr - updated attributes + * + * Check that an RPC call that returned attributes has not overlapped with + * other recent updates of the inode metadata, then decide whether it is + * safe to do a full update of the inode attributes, or whether just to + * call nfs_check_inode_attributes. + */ +int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) +{ + struct nfs_inode *nfsi = NFS_I(inode); + int status; + + if ((fattr->valid & NFS_ATTR_FATTR) == 0) + return 0; + spin_lock(&inode->i_lock); + nfsi->cache_validity &= ~NFS_INO_REVAL_PAGECACHE; + if (nfs_verify_change_attribute(inode, fattr->time_start)) + nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME); + if (time_after(fattr->time_start, nfsi->last_updated)) + status = nfs_update_inode(inode, fattr, fattr->time_start); + else + status = nfs_check_inode_attributes(inode, fattr); + + spin_unlock(&inode->i_lock); + return status; +} + /* * Many nfs protocol calls return the new file attributes after * an operation. Here we update the inode to reflect the state @@ -1365,20 +1395,17 @@ static int nfs_update_inode(struct inode goto out_err; } - spin_lock(&inode->i_lock); - /* * Make sure the inode's type hasn't changed. */ - if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) { - spin_unlock(&inode->i_lock); + if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT)) goto out_changed; - } /* * Update the read time so we don't revalidate too often. */ - nfsi->read_cache_jiffies = fattr->timestamp; + nfsi->read_cache_jiffies = fattr->time_start; + nfsi->last_updated = jiffies; /* Are we racing with known updates of the metadata on the server? */ data_unstable = ! (nfs_verify_change_attribute(inode, verifier) || @@ -1467,7 +1494,6 @@ static int nfs_update_inode(struct inode if (!nfs_have_delegation(inode, FMODE_READ)) nfsi->cache_validity |= invalid; - spin_unlock(&inode->i_lock); return 0; out_changed: /* Index: linux-2.6/fs/nfs/nfs2xdr.c =================================================================== --- linux-2.6.orig/fs/nfs/nfs2xdr.c +++ linux-2.6/fs/nfs/nfs2xdr.c @@ -143,7 +143,6 @@ xdr_decode_fattr(u32 *p, struct nfs_fatt fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO; fattr->rdev = 0; } - fattr->timestamp = jiffies; return p; } Index: linux-2.6/fs/nfs/nfs3xdr.c =================================================================== --- linux-2.6.orig/fs/nfs/nfs3xdr.c +++ linux-2.6/fs/nfs/nfs3xdr.c @@ -174,7 +174,6 @@ xdr_decode_fattr(u32 *p, struct nfs_fatt /* Update the mode bits */ fattr->valid |= (NFS_ATTR_FATTR | NFS_ATTR_FATTR_V3); - fattr->timestamp = jiffies; return p; } Index: linux-2.6/fs/nfs/nfs4xdr.c =================================================================== --- linux-2.6.orig/fs/nfs/nfs4xdr.c +++ linux-2.6/fs/nfs/nfs4xdr.c @@ -2799,10 +2799,8 @@ static int decode_getfattr(struct xdr_st goto xdr_error; if ((status = decode_attr_time_modify(xdr, bitmap, &fattr->mtime)) != 0) goto xdr_error; - if ((status = verify_attr_len(xdr, savep, attrlen)) == 0) { + if ((status = verify_attr_len(xdr, savep, attrlen)) == 0) fattr->valid = NFS_ATTR_FATTR | NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4; - fattr->timestamp = jiffies; - } xdr_error: if (status != 0) printk(KERN_NOTICE "%s: xdr error %d!\n", __FUNCTION__, -status);