3 files changed, 70 insertions, 6 deletions

diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index dbbefbcd6712..1adcf93cb6e6 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -18,6 +18,8 @@
 #include <linux/lockd/lockd.h>
 #include <linux/lockd/share.h>
 #include <linux/lockd/sm_inter.h>
+#include <linux/module.h>
+#include <linux/mount.h>
 
 #define NLMDBG_FACILITY         NLMDBG_SVCSUBS
 
@@ -230,7 +232,7 @@ nlm_file_inuse(struct nlm_file *file)
  * Loop over all files in the file table.
  */
 static int
-nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match)
+nlm_traverse_files(void *data, nlm_host_match_fn_t match)
 {
         struct hlist_node *pos, *next;
         struct nlm_file *file;
@@ -244,7 +246,7 @@ nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match)
 
                         /* Traverse locks, blocks and shares of this file
                          * and update file->f_locks count */
-                        if (nlm_inspect_file(host, file, match))
+                        if (nlm_inspect_file(data, file, match))
                                 ret = 1;
 
                         mutex_lock(&nlm_file_mutex);
@@ -303,21 +305,27 @@ nlm_release_file(struct nlm_file *file)
  *      Used by nlmsvc_invalidate_all
  */
 static int
-nlmsvc_mark_host(struct nlm_host *host, struct nlm_host *dummy)
+nlmsvc_mark_host(void *data, struct nlm_host *dummy)
 {
+        struct nlm_host *host = data;
+
         host->h_inuse = 1;
         return 0;
 }
 
 static int
-nlmsvc_same_host(struct nlm_host *host, struct nlm_host *other)
+nlmsvc_same_host(void *data, struct nlm_host *other)
 {
+        struct nlm_host *host = data;
+
         return host == other;
 }
 
 static int
-nlmsvc_is_client(struct nlm_host *host, struct nlm_host *dummy)
+nlmsvc_is_client(void *data, struct nlm_host *dummy)
 {
+        struct nlm_host *host = data;
+
         if (host->h_server) {
                 /* we are destroying locks even though the client
                  * hasn't asked us too, so don't unmonitor the
@@ -370,3 +378,21 @@ nlmsvc_invalidate_all(void)
          */
         nlm_traverse_files(NULL, nlmsvc_is_client);
 }
+
+static int
+nlmsvc_match_ip(void *datap, struct nlm_host *host)
+{
+        __be32 *server_addr = datap;
+
+        return host->h_saddr.sin_addr.s_addr == *server_addr;
+}
+
+int
+nlmsvc_unlock_all_by_ip(__be32 server_addr)
+{
+        int ret;
+        ret = nlm_traverse_files(&server_addr, nlmsvc_match_ip);
+        return ret ? -EIO : 0;
+
+}
+EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 613bcb8171a5..7706f6c9ab8a 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -22,6 +22,7 @@
 #include <linux/seq_file.h>
 #include <linux/pagemap.h>
 #include <linux/init.h>
+#include <linux/inet.h>
 #include <linux/string.h>
 #include <linux/smp_lock.h>
 #include <linux/ctype.h>
@@ -35,6 +36,7 @@
 #include <linux/nfsd/cache.h>
 #include <linux/nfsd/xdr.h>
 #include <linux/nfsd/syscall.h>
+#include <linux/lockd/lockd.h>
 
 #include <asm/uaccess.h>
 #include <net/ipv6.h>
@@ -53,6 +55,7 @@ enum {
         NFSD_Getfs,
         NFSD_List,
         NFSD_Fh,
+        NFSD_FO_UnlockIP,
         NFSD_Threads,
         NFSD_Pool_Threads,
         NFSD_Versions,
@@ -89,6 +92,8 @@ static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
 #endif
 
+static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size);
+
 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
         [NFSD_Svc] = write_svc,
         [NFSD_Add] = write_add,
@@ -98,6 +103,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
         [NFSD_Getfd] = write_getfd,
         [NFSD_Getfs] = write_getfs,
         [NFSD_Fh] = write_filehandle,
+        [NFSD_FO_UnlockIP] = failover_unlock_ip,
         [NFSD_Threads] = write_threads,
         [NFSD_Pool_Threads] = write_pool_threads,
         [NFSD_Versions] = write_versions,
@@ -298,6 +304,31 @@ static ssize_t write_getfd(struct file *file, char *buf, size_t size)
         return err;
 }
 
+static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size)
+{
+        __be32 server_ip;
+        char *fo_path, c;
+        int b1, b2, b3, b4;
+
+        /* sanity check */
+        if (size == 0)
+                return -EINVAL;
+
+        if (buf[size-1] != '\n')
+                return -EINVAL;
+
+        fo_path = buf;
+        if (qword_get(&buf, fo_path, size) < 0)
+                return -EINVAL;
+
+        /* get ipv4 address */
+        if (sscanf(fo_path, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
+                return -EINVAL;
+        server_ip = htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
+
+        return nlmsvc_unlock_all_by_ip(server_ip);
+}
+
 static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
 {
         /* request is:
@@ -700,6 +731,8 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
                 [NFSD_Getfd] = {".getfd", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_Getfs] = {".getfs", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_List] = {"exports", &exports_operations, S_IRUGO},
+                [NFSD_FO_UnlockIP] = {"unlock_ip",
+                                        &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 94649a8da014..bcb93fc1fce7 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -194,7 +194,7 @@ void		  nsm_release(struct nsm_handle *);
  * This is used in garbage collection and resource reclaim
  * A return value != 0 means destroy the lock/block/share
  */
-typedef int       (*nlm_host_match_fn_t)(struct nlm_host *cur, struct nlm_host *ref);
+typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 
 /*
  * Server-side lock handling
@@ -220,6 +220,11 @@ void		  nlmsvc_mark_resources(void);
 void              nlmsvc_free_host_resources(struct nlm_host *);
 void              nlmsvc_invalidate_all(void);
 
+/*
+ * Cluster failover support
+ */
+int           nlmsvc_unlock_all_by_ip(__be32 server_addr);
+
 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 {
         return file->f_file->f_path.dentry->d_inode;