[PATCH 3.2 29/87] NFS: Fix attribute cache revalidation

[Ben Hutchings]

3.2.77-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit ade14a7df796d4e86bd9d181193c883a57b13db0 upstream.

If a NFSv4 client uses the cache_consistency_bitmask in order to
request only information about the change attribute, timestamps and
size, then it has not revalidated all attributes, and hence the
attribute timeout timestamp should not be updated.

Reported-by: Donald Buczek <buczek@xxxxxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/nfs/inode.c | 54 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 15 deletions(-)

--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1207,6 +1207,7 @@ static int nfs_update_inode(struct inode
 	unsigned long invalid = 0;
 	unsigned long now = jiffies;
 	unsigned long save_cache_validity;
+	bool cache_revalidated = true;
 
 	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
 			__func__, inode->i_sb->s_id, inode->i_ino,
@@ -1252,8 +1253,10 @@ static int nfs_update_inode(struct inode
 				nfs_force_lookup_revalidate(inode);
 			inode->i_version = fattr->change_attr;
 		}
-	} else if (server->caps & NFS_CAP_CHANGE_ATTR)
+	} else if (server->caps & NFS_CAP_CHANGE_ATTR) {
 		invalid |= save_cache_validity;
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
 		/* NFSv2/v3: Check if the mtime agrees */
@@ -1265,11 +1268,13 @@ static int nfs_update_inode(struct inode
 				nfs_force_lookup_revalidate(inode);
 			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
 		}
-	} else if (server->caps & NFS_CAP_MTIME)
+	} else if (server->caps & NFS_CAP_MTIME) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_INVALID_DATA
 				| NFS_INO_REVAL_PAGECACHE
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
 		/* If ctime has changed we should definitely clear access+acl caches */
@@ -1284,11 +1289,13 @@ static int nfs_update_inode(struct inode
 			}
 			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
 		}
-	} else if (server->caps & NFS_CAP_CTIME)
+	} else if (server->caps & NFS_CAP_CTIME) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	/* Check if our cached file size is stale */
 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
@@ -1309,17 +1316,21 @@ static int nfs_update_inode(struct inode
 					(long long)cur_isize,
 					(long long)new_isize);
 		}
-	} else
+	} else {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_REVAL_PAGECACHE
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 
 	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
 		memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
-	else if (server->caps & NFS_CAP_ATIME)
+	else if (server->caps & NFS_CAP_ATIME) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
 		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
@@ -1328,33 +1339,39 @@ static int nfs_update_inode(struct inode
 			inode->i_mode = newmode;
 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
 		}
-	} else if (server->caps & NFS_CAP_MODE)
+	} else if (server->caps & NFS_CAP_MODE) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
 		if (inode->i_uid != fattr->uid) {
 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
 			inode->i_uid = fattr->uid;
 		}
-	} else if (server->caps & NFS_CAP_OWNER)
+	} else if (server->caps & NFS_CAP_OWNER) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
 		if (inode->i_gid != fattr->gid) {
 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
 			inode->i_gid = fattr->gid;
 		}
-	} else if (server->caps & NFS_CAP_OWNER_GROUP)
+	} else if (server->caps & NFS_CAP_OWNER_GROUP) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
 		if (inode->i_nlink != fattr->nlink) {
@@ -1363,18 +1380,21 @@ static int nfs_update_inode(struct inode
 				invalid |= NFS_INO_INVALID_DATA;
 			set_nlink(inode, fattr->nlink);
 		}
-	} else if (server->caps & NFS_CAP_NLINK)
+	} else if (server->caps & NFS_CAP_NLINK) {
 		invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
 				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
 
 	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
 		/*
 		 * report the blocks in 512byte units
 		 */
 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
- 	}
-	if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
+	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
 		inode->i_blocks = fattr->du.nfs2.blocks;
+	else
+		cache_revalidated = false;
 
 	/* Update attrtimeo value if we're out of the unstable period */
 	if (invalid & NFS_INO_INVALID_ATTR) {
@@ -1383,15 +1403,19 @@ static int nfs_update_inode(struct inode
 		nfsi->attrtimeo_timestamp = now;
 		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
 	} else {
-		if (!time_in_range_open(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
-			if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
-				nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
+		if (cache_revalidated) {
+			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
+				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
+				nfsi->attrtimeo <<= 1;
+				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
+					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
+			}
 			nfsi->attrtimeo_timestamp = now;
 		}
 	}
 
 	/* Don't declare attrcache up to date if there were no attrs! */
-	if (fattr->valid != 0)
+	if (cache_revalidated)
 		invalid &= ~NFS_INO_INVALID_ATTR;
 
 	/* Don't invalidate the data if we were to blame */