[RFC] cifs: add attribute cache timeout (actimeo) tunable

Commit Message

Suresh Jayaraman Nov. 16, 2010, 10:09 a.m. UTC

None

Patch

diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index e9a393c..efd2d73 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 int actimeo;
 	atomic_t active;
 	uid_t	mnt_uid;
 	gid_t	mnt_gid;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index b577bf0..eb22130 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -44,6 +44,9 @@ 
 
 #define CIFS_MIN_RCV_POOL 4
 
+#define CIFS_DEF_ACTIMEO (3)	/* default attribute cache timeout (seconds) */
+#define CIFS_MAX_ACTIMEO (60)	/* max allowed attribute cache timeout */
+
 /*
  * MAX_REQ is the maximum number of requests that WE will send
  * on one socket concurrently. It also matches the most common
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 251a17c..39edc54 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -103,6 +103,7 @@  struct smb_vol {
 	bool multiuser:1;
 	unsigned int rsize;
 	unsigned int wsize;
+	unsigned int actimeo; /* attribute cache timeout */
 	bool sockopt_tcp_nodelay:1;
 	unsigned short int port;
 	char *prepath;
@@ -1214,6 +1215,10 @@  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 =
+					simple_strtoul(value, &value, 0);
 		} else if (strnicmp(data, "credentials", 4) == 0) {
 			/* ignore */
 		} else if (strnicmp(data, "version", 3) == 0) {
@@ -2566,6 +2571,17 @@  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);
 
+	if ((pvolume_info->actimeo) &&
+			(pvolume_info->actimeo < CIFS_MAX_ACTIMEO))
+		cifs_sb->actimeo = pvolume_info->actimeo;
+	else if ((pvolume_info->actimeo) &&
+			(pvolume_info->actimeo >= CIFS_MAX_ACTIMEO)) {
+		cifs_sb->actimeo = CIFS_MAX_ACTIMEO;
+		cERROR(1, "actimeo %d too large, using %d instead",
+				pvolume_info->actimeo, CIFS_MAX_ACTIMEO);
+	} else /* default */
+		cifs_sb->actimeo = CIFS_DEF_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 ff7d299..f30700d 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1648,6 +1648,7 @@  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;
@@ -1658,12 +1659,11 @@  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_after_eq(jiffies, cifs_i->time + (cifs_sb->actimeo * HZ)))
 		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;