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NFS: Fix a wraparound issue with nfsi->cache_change_attribute

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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>
This commit is contained in:
Trond Myklebust 2007-02-05 14:26:28 -08:00
parent ebf4d8ec02
commit 3e7d950a52
1 changed files with 13 additions and 8 deletions
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21
fs/nfs/inode.c
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@ -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)