[-v5] cifs: add attribute cache timeout (actimeo) tunable
diff mbox

Message ID 1291194748-9455-1-git-send-email-sjayaraman@suse.de
State New, archived
Headers show

Commit Message

Suresh Jayaraman Dec. 1, 2010, 9:12 a.m. UTC
None

Patch
diff mbox

diff --git a/fs/cifs/README b/fs/cifs/README
index ee68d10..46af99a 100644
--- a/fs/cifs/README
+++ b/fs/cifs/README
@@ -337,6 +337,15 @@  A partial list of the supported mount options follows:
   wsize		default write size (default 57344)
 		maximum wsize currently allowed by CIFS is 57344 (fourteen
 		4096 byte pages)
+  actimeo=n	attribute cache timeout in seconds (default 1 second).
+		After this timeout, the cifs client requests fresh attribute
+		information from the server. This option allows to tune the
+		attribute cache timeout to suit the workload needs. Shorter
+		timeouts mean better the cache coherency, but increased number
+		of calls to the server. Longer timeouts mean reduced number
+		of calls to the server at the expense of less stricter cache
+		coherency checks (i.e. incorrect attribute cache for a short
+		period of time).
   rw		mount the network share read-write (note that the
 		server may still consider the share read-only)
   ro		mount network share read-only
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index e9a393c..7852cd6 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -48,6 +48,7 @@  struct cifs_sb_info {
 	struct nls_table *local_nls;
 	unsigned int rsize;
 	unsigned int wsize;
+	unsigned long actimeo; /* attribute cache timeout (jiffies) */
 	atomic_t active;
 	uid_t	mnt_uid;
 	gid_t	mnt_gid;
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 76c8a90..56a4b75 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -463,6 +463,8 @@  cifs_show_options(struct seq_file *s, struct vfsmount *m)
 
 	seq_printf(s, ",rsize=%d", cifs_sb->rsize);
 	seq_printf(s, ",wsize=%d", cifs_sb->wsize);
+	/* convert actimeo and display it in seconds */
+		seq_printf(s, ",actimeo=%lu", cifs_sb->actimeo / HZ);
 
 	return 0;
 }
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index b577bf0..94ccfac 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -45,6 +45,16 @@ 
 #define CIFS_MIN_RCV_POOL 4
 
 /*
+ * default attribute cache timeout (jiffies)
+ */
+#define CIFS_DEF_ACTIMEO (1 * HZ)
+
+/*
+ * max attribute cache timeout (jiffies) - 2^30
+ */
+#define CIFS_MAX_ACTIMEO (1 << 30)
+
+/*
  * MAX_REQ is the maximum number of requests that WE will send
  * on one socket concurrently. It also matches the most common
  * value of max multiplex returned by servers.  We may
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 32fa4d9..bb17ee2 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -105,6 +105,7 @@  struct smb_vol {
 	unsigned int wsize;
 	bool sockopt_tcp_nodelay:1;
 	unsigned short int port;
+	unsigned long actimeo; /* attribute cache timeout (jiffies) */
 	char *prepath;
 	struct sockaddr_storage srcaddr; /* allow binding to a local IP */
 	struct nls_table *local_nls;
@@ -840,6 +841,8 @@  cifs_parse_mount_options(char *options, const char *devname,
 	/* default to using server inode numbers where available */
 	vol->server_ino = 1;
 
+	vol->actimeo = CIFS_DEF_ACTIMEO;
+
 	if (!options)
 		return 1;
 
@@ -1214,6 +1217,16 @@  cifs_parse_mount_options(char *options, const char *devname,
 					printk(KERN_WARNING "CIFS: server net"
 					"biosname longer than 15 truncated.\n");
 			}
+		} else if (strnicmp(data, "actimeo", 7) == 0) {
+			if (value && *value) {
+				vol->actimeo = HZ * simple_strtoul(value,
+								   &value, 0);
+				if (vol->actimeo > CIFS_MAX_ACTIMEO) {
+					cERROR(1, "CIFS: attribute cache"
+							"timeout too large");
+					return 1;
+				}
+			}
 		} else if (strnicmp(data, "credentials", 4) == 0) {
 			/* ignore */
 		} else if (strnicmp(data, "version", 3) == 0) {
@@ -2571,6 +2584,8 @@  static void setup_cifs_sb(struct smb_vol *pvolume_info,
 	cFYI(1, "file mode: 0x%x  dir mode: 0x%x",
 		cifs_sb->mnt_file_mode, cifs_sb->mnt_dir_mode);
 
+	cifs_sb->actimeo = pvolume_info->actimeo;
+
 	if (pvolume_info->noperm)
 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_PERM;
 	if (pvolume_info->setuids)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 28cb6e7..bb5ca48 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1653,6 +1653,7 @@  static bool
 cifs_inode_needs_reval(struct inode *inode)
 {
 	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 
 	if (cifs_i->clientCanCacheRead)
 		return false;
@@ -1663,12 +1664,12 @@  cifs_inode_needs_reval(struct inode *inode)
 	if (cifs_i->time == 0)
 		return true;
 
-	/* FIXME: the actimeo should be tunable */
-	if (time_after_eq(jiffies, cifs_i->time + HZ))
+	if (!time_in_range(jiffies, cifs_i->time,
+				cifs_i->time + cifs_sb->actimeo))
 		return true;
 
 	/* hardlinked files w/ noserverino get "special" treatment */
-	if (!(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) &&
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) &&
 	    S_ISREG(inode->i_mode) && inode->i_nlink != 1)
 		return true;