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[linux-2.6-omap-h63xx.git] / fs / nfs / inode.c

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e25009f35cc26e969c01cc9a720562fc86365fec..dc52793ff8f8a06ddf1d89d62d7bb44fb9eee740 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -5,7 +5,7 @@
  *
  *  nfs inode and superblock handling functions
  *
- *  Modularised by Alan Cox <Alan.Cox@linux.org>, while hacking some
+ *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  *
  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
@@ -305,8 +305,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
                        init_special_inode(inode, inode->i_mode, fattr->rdev);
 
                nfsi->read_cache_jiffies = fattr->time_start;
-               nfsi->last_updated = now;
-               nfsi->cache_change_attribute = now;
+               nfsi->attr_gencount = fattr->gencount;
                inode->i_atime = fattr->atime;
                inode->i_mtime = fattr->mtime;
                inode->i_ctime = fattr->ctime;
@@ -909,6 +908,30 @@ static int nfs_size_need_update(const struct inode *inode, const struct nfs_fatt
        return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
 }
 
+static unsigned long nfs_attr_generation_counter;
+
+static unsigned long nfs_read_attr_generation_counter(void)
+{
+       smp_rmb();
+       return nfs_attr_generation_counter;
+}
+
+unsigned long nfs_inc_attr_generation_counter(void)
+{
+       unsigned long ret;
+       smp_rmb();
+       ret = ++nfs_attr_generation_counter;
+       smp_wmb();
+       return ret;
+}
+
+void nfs_fattr_init(struct nfs_fattr *fattr)
+{
+       fattr->valid = 0;
+       fattr->time_start = jiffies;
+       fattr->gencount = nfs_inc_attr_generation_counter();
+}
+
 /**
  * nfs_inode_attrs_need_update - check if the inode attributes need updating
  * @inode - pointer to inode
@@ -922,8 +945,7 @@ static int nfs_size_need_update(const struct inode *inode, const struct nfs_fatt
  * catch the case where ctime either didn't change, or went backwards
  * (if someone reset the clock on the server) by looking at whether
  * or not this RPC call was started after the inode was last updated.
- * Note also the check for jiffy wraparound if the last_updated timestamp
- * is later than 'jiffies'.
+ * Note also the check for wraparound of 'attr_gencount'
  *
  * The function returns 'true' if it thinks the attributes in 'fattr' are
  * more recent than the ones cached in the inode.
@@ -933,10 +955,10 @@ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct n
 {
        const struct nfs_inode *nfsi = NFS_I(inode);
 
-       return nfs_ctime_need_update(inode, fattr) ||
-                       nfs_size_need_update(inode, fattr) ||
-                       time_after(fattr->time_start, nfsi->last_updated) ||
-                       time_after(nfsi->last_updated, jiffies);
+       return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 ||
+               nfs_ctime_need_update(inode, fattr) ||
+               nfs_size_need_update(inode, fattr) ||
+               ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0);
 }
 
 static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
@@ -1107,7 +1129,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                }
                /* 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;
+                       invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
        } else if (nfsi->change_attr != fattr->change_attr) {
                dprintk("NFS: change_attr change on server for file %s/%ld\n",
                                inode->i_sb->s_id, inode->i_ino);
@@ -1141,6 +1163,9 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
            inode->i_gid != fattr->gid)
                invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
 
+       if (inode->i_nlink != fattr->nlink)
+               invalid |= NFS_INO_INVALID_ATTR;
+
        inode->i_mode = fattr->mode;
        inode->i_nlink = fattr->nlink;
        inode->i_uid = fattr->uid;
@@ -1160,18 +1185,13 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
                nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
                nfsi->attrtimeo_timestamp = now;
-               nfsi->last_updated = now;
+               nfsi->attr_gencount = nfs_inc_attr_generation_counter();
        } else {
                if (!time_in_range(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
                        if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
                                nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
                        nfsi->attrtimeo_timestamp = now;
                }
-               /*
-                * Avoid jiffy wraparound issues with nfsi->last_updated
-                */
-               if (!time_in_range(nfsi->last_updated, nfsi->read_cache_jiffies, now))
-                       nfsi->last_updated = nfsi->read_cache_jiffies;
        }
        invalid &= ~NFS_INO_INVALID_ATTR;
        /* Don't invalidate the data if we were to blame */