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 <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 4ef4547..93269c3 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -939,6 +939,7 @@
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 @@
* 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 @@
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 @@
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 @@
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)