From: Trond Myklebust Date: Mon, 5 Feb 2007 22:26:28 +0000 (-0800) Subject: NFS: Fix a wraparound issue with nfsi->cache_change_attribute X-Git-Tag: v2.6.21-rc1~278 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=3e7d950a528454ad749a264feef3c8bad3faa108;p=linux-2.6-omap-h63xx.git NFS: Fix a wraparound issue with nfsi->cache_change_attribute Fix wraparound issue with nfsi->cache_change_attribute. If it is found to lie in the future, then update it to lie in the past. Patch based on a suggestion by Neil Brown. ..and minor micro-optimisation: avoid reading 'jiffies' more than once in nfs_update_inode(). Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 4ef45476388..93269c3dd0f 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -939,6 +939,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) struct nfs_inode *nfsi = NFS_I(inode); loff_t cur_isize, new_isize; unsigned int invalid = 0; + unsigned long now = jiffies; int data_stable; dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n", @@ -964,7 +965,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) * Update the read time so we don't revalidate too often. */ nfsi->read_cache_jiffies = fattr->time_start; - nfsi->last_updated = jiffies; + nfsi->last_updated = now; + + /* Fix a wraparound issue with nfsi->cache_change_attribute */ + if (time_before(now, nfsi->cache_change_attribute)) + nfsi->cache_change_attribute = now - 600*HZ; /* Are we racing with known updates of the metadata on the server? */ data_stable = nfs_verify_change_attribute(inode, fattr->time_start); @@ -990,7 +995,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) inode->i_size = new_isize; invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA; } - nfsi->cache_change_attribute = jiffies; + nfsi->cache_change_attribute = now; dprintk("NFS: isize change on server for file %s/%ld\n", inode->i_sb->s_id, inode->i_ino); } @@ -1001,14 +1006,14 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) dprintk("NFS: mtime change on server for file %s/%ld\n", inode->i_sb->s_id, inode->i_ino); invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA; - nfsi->cache_change_attribute = jiffies; + nfsi->cache_change_attribute = now; } /* If ctime has changed we should definitely clear access+acl caches */ if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) { invalid |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime)); - nfsi->cache_change_attribute = jiffies; + nfsi->cache_change_attribute = now; } memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime)); @@ -1037,18 +1042,18 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) inode->i_sb->s_id, inode->i_ino); nfsi->change_attr = fattr->change_attr; invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; - nfsi->cache_change_attribute = jiffies; + nfsi->cache_change_attribute = now; } /* Update attrtimeo value if we're out of the unstable period */ if (invalid & NFS_INO_INVALID_ATTR) { nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE); nfsi->attrtimeo = NFS_MINATTRTIMEO(inode); - nfsi->attrtimeo_timestamp = jiffies; - } else if (time_after(jiffies, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) { + nfsi->attrtimeo_timestamp = now; + } else if (time_after(now, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) { if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode)) nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode); - nfsi->attrtimeo_timestamp = jiffies; + nfsi->attrtimeo_timestamp = now; } /* Don't invalidate the data if we were to blame */ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)