fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / fs / lockd / svcsubs.c
index 62f4a38..c0df00c 100644 (file)
@@ -6,11 +6,11 @@
  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  */
 
-#include <linux/config.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/time.h>
 #include <linux/in.h>
+#include <linux/mutex.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfsd/nfsfh.h>
 /*
  * Global file hash table
  */
-#define FILE_HASH_BITS         5
+#define FILE_HASH_BITS         7
 #define FILE_NRHASH            (1<<FILE_HASH_BITS)
-static struct nlm_file *       nlm_files[FILE_NRHASH];
-static DECLARE_MUTEX(nlm_file_sema);
+static struct hlist_head       nlm_files[FILE_NRHASH];
+static DEFINE_MUTEX(nlm_file_mutex);
 
 #ifdef NFSD_DEBUG
 static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
@@ -43,7 +43,7 @@ static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
 
 static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
 {
-       struct inode *inode = file->f_file->f_dentry->d_inode;
+       struct inode *inode = file->f_file->f_path.dentry->d_inode;
 
        dprintk("lockd: %s %s/%ld\n",
                msg, inode->i_sb->s_id, inode->i_ino);
@@ -78,36 +78,37 @@ static inline unsigned int file_hash(struct nfs_fh *f)
  * This is not quite right, but for now, we assume the client performs
  * the proper R/W checking.
  */
-u32
+__be32
 nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
                                        struct nfs_fh *f)
 {
+       struct hlist_node *pos;
        struct nlm_file *file;
        unsigned int    hash;
-       u32             nfserr;
+       __be32          nfserr;
 
        nlm_debug_print_fh("nlm_file_lookup", f);
 
        hash = file_hash(f);
 
        /* Lock file table */
-       down(&nlm_file_sema);
+       mutex_lock(&nlm_file_mutex);
 
-       for (file = nlm_files[hash]; file; file = file->f_next)
+       hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
                if (!nfs_compare_fh(&file->f_handle, f))
                        goto found;
 
        nlm_debug_print_fh("creating file for", f);
 
        nfserr = nlm_lck_denied_nolocks;
-       file = (struct nlm_file *) kmalloc(sizeof(*file), GFP_KERNEL);
+       file = kzalloc(sizeof(*file), GFP_KERNEL);
        if (!file)
                goto out_unlock;
 
-       memset(file, 0, sizeof(*file));
        memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
-       file->f_hash = hash;
-       init_MUTEX(&file->f_sema);
+       mutex_init(&file->f_mutex);
+       INIT_HLIST_NODE(&file->f_list);
+       INIT_LIST_HEAD(&file->f_blocks);
 
        /* Open the file. Note that this must not sleep for too long, else
         * we would lock up lockd:-) So no NFS re-exports, folks.
@@ -116,12 +117,11 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
         * the file.
         */
        if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
-               dprintk("lockd: open failed (nfserr %d)\n", ntohl(nfserr));
+               dprintk("lockd: open failed (error %d)\n", nfserr);
                goto out_free;
        }
 
-       file->f_next = nlm_files[hash];
-       nlm_files[hash] = file;
+       hlist_add_head(&file->f_list, &nlm_files[hash]);
 
 found:
        dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
@@ -130,17 +130,11 @@ found:
        nfserr = 0;
 
 out_unlock:
-       up(&nlm_file_sema);
+       mutex_unlock(&nlm_file_mutex);
        return nfserr;
 
 out_free:
        kfree(file);
-#ifdef CONFIG_LOCKD_V4
-       if (nfserr == 1)
-               nfserr = nlm4_stale_fh;
-       else
-#endif
-       nfserr = nlm_lck_denied;
        goto out_unlock;
 }
 
@@ -150,22 +144,14 @@ out_free:
 static inline void
 nlm_delete_file(struct nlm_file *file)
 {
-       struct nlm_file **fp, *f;
-
        nlm_debug_print_file("closing file", file);
-
-       fp = nlm_files + file->f_hash;
-       while ((f = *fp) != NULL) {
-               if (f == file) {
-                       *fp = file->f_next;
-                       nlmsvc_ops->fclose(file->f_file);
-                       kfree(file);
-                       return;
-               }
-               fp = &f->f_next;
+       if (!hlist_unhashed(&file->f_list)) {
+               hlist_del(&file->f_list);
+               nlmsvc_ops->fclose(file->f_file);
+               kfree(file);
+       } else {
+               printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
        }
-
-       printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
 }
 
 /*
@@ -173,7 +159,8 @@ nlm_delete_file(struct nlm_file *file)
  * action.
  */
 static int
-nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file, int action)
+nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
+                       nlm_host_match_fn_t match)
 {
        struct inode     *inode = nlmsvc_file_inode(file);
        struct file_lock *fl;
@@ -182,22 +169,16 @@ nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file, int action)
 again:
        file->f_locks = 0;
        for (fl = inode->i_flock; fl; fl = fl->fl_next) {
-               if (!(fl->fl_flags & FL_LOCKD))
+               if (fl->fl_lmops != &nlmsvc_lock_operations)
                        continue;
 
                /* update current lock count */
                file->f_locks++;
+
                lockhost = (struct nlm_host *) fl->fl_owner;
-               if (action == NLM_ACT_MARK)
-                       lockhost->h_inuse = 1;
-               else if (action == NLM_ACT_CHECK)
-                       return 1;
-               else if (action == NLM_ACT_UNLOCK) {
+               if (match(lockhost, host)) {
                        struct file_lock lock = *fl;
 
-                       if (host && lockhost != host)
-                               continue;
-
                        lock.fl_type  = F_UNLCK;
                        lock.fl_start = 0;
                        lock.fl_end   = OFFSET_MAX;
@@ -214,56 +195,71 @@ again:
 }
 
 /*
- * Operate on a single file
+ * Inspect a single file
  */
 static inline int
-nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, int action)
+nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
 {
-       if (action == NLM_ACT_CHECK) {
-               /* Fast path for mark and sweep garbage collection */
-               if (file->f_count || file->f_blocks || file->f_shares)
-                       return 1;
-       } else {
-               if (nlmsvc_traverse_blocks(host, file, action)
-                || nlmsvc_traverse_shares(host, file, action))
+       nlmsvc_traverse_blocks(host, file, match);
+       nlmsvc_traverse_shares(host, file, match);
+       return nlm_traverse_locks(host, file, match);
+}
+
+/*
+ * Quick check whether there are still any locks, blocks or
+ * shares on a given file.
+ */
+static inline int
+nlm_file_inuse(struct nlm_file *file)
+{
+       struct inode     *inode = nlmsvc_file_inode(file);
+       struct file_lock *fl;
+
+       if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
+               return 1;
+
+       for (fl = inode->i_flock; fl; fl = fl->fl_next) {
+               if (fl->fl_lmops == &nlmsvc_lock_operations)
                        return 1;
        }
-       return nlm_traverse_locks(host, file, action);
+       file->f_locks = 0;
+       return 0;
 }
 
 /*
  * Loop over all files in the file table.
  */
 static int
-nlm_traverse_files(struct nlm_host *host, int action)
+nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match)
 {
-       struct nlm_file *file, **fp;
-       int             i;
+       struct hlist_node *pos, *next;
+       struct nlm_file *file;
+       int i, ret = 0;
 
-       down(&nlm_file_sema);
+       mutex_lock(&nlm_file_mutex);
        for (i = 0; i < FILE_NRHASH; i++) {
-               fp = nlm_files + i;
-               while ((file = *fp) != NULL) {
+               hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
+                       file->f_count++;
+                       mutex_unlock(&nlm_file_mutex);
+
                        /* Traverse locks, blocks and shares of this file
                         * and update file->f_locks count */
-                       if (nlm_inspect_file(host, file, action)) {
-                               up(&nlm_file_sema);
-                               return 1;
-                       }
+                       if (nlm_inspect_file(host, file, match))
+                               ret = 1;
 
+                       mutex_lock(&nlm_file_mutex);
+                       file->f_count--;
                        /* No more references to this file. Let go of it. */
-                       if (!file->f_blocks && !file->f_locks
+                       if (list_empty(&file->f_blocks) && !file->f_locks
                         && !file->f_shares && !file->f_count) {
-                               *fp = file->f_next;
+                               hlist_del(&file->f_list);
                                nlmsvc_ops->fclose(file->f_file);
                                kfree(file);
-                       } else {
-                               fp = &file->f_next;
                        }
                }
        }
-       up(&nlm_file_sema);
-       return 0;
+       mutex_unlock(&nlm_file_mutex);
+       return ret;
 }
 
 /*
@@ -282,15 +278,56 @@ nlm_release_file(struct nlm_file *file)
                                file, file->f_count);
 
        /* Lock file table */
-       down(&nlm_file_sema);
+       mutex_lock(&nlm_file_mutex);
 
        /* If there are no more locks etc, delete the file */
-       if(--file->f_count == 0) {
-               if(!nlm_inspect_file(NULL, file, NLM_ACT_CHECK))
-                       nlm_delete_file(file);
-       }
+       if (--file->f_count == 0 && !nlm_file_inuse(file))
+               nlm_delete_file(file);
+
+       mutex_unlock(&nlm_file_mutex);
+}
+
+/*
+ * Helpers function for resource traversal
+ *
+ * nlmsvc_mark_host:
+ *     used by the garbage collector; simply sets h_inuse.
+ *     Always returns 0.
+ *
+ * nlmsvc_same_host:
+ *     returns 1 iff the two hosts match. Used to release
+ *     all resources bound to a specific host.
+ *
+ * nlmsvc_is_client:
+ *     returns 1 iff the host is a client.
+ *     Used by nlmsvc_invalidate_all
+ */
+static int
+nlmsvc_mark_host(struct nlm_host *host, struct nlm_host *dummy)
+{
+       host->h_inuse = 1;
+       return 0;
+}
 
-       up(&nlm_file_sema);
+static int
+nlmsvc_same_host(struct nlm_host *host, struct nlm_host *other)
+{
+       return host == other;
+}
+
+static int
+nlmsvc_is_client(struct nlm_host *host, struct nlm_host *dummy)
+{
+       if (host->h_server) {
+               /* we are destroying locks even though the client
+                * hasn't asked us too, so don't unmonitor the
+                * client
+                */
+               if (host->h_nsmhandle)
+                       host->h_nsmhandle->sm_sticky = 1;
+               return 1;
+       } else
+               return 0;
 }
 
 /*
@@ -300,8 +337,7 @@ void
 nlmsvc_mark_resources(void)
 {
        dprintk("lockd: nlmsvc_mark_resources\n");
-
-       nlm_traverse_files(NULL, NLM_ACT_MARK);
+       nlm_traverse_files(NULL, nlmsvc_mark_host);
 }
 
 /*
@@ -312,23 +348,25 @@ nlmsvc_free_host_resources(struct nlm_host *host)
 {
        dprintk("lockd: nlmsvc_free_host_resources\n");
 
-       if (nlm_traverse_files(host, NLM_ACT_UNLOCK))
+       if (nlm_traverse_files(host, nlmsvc_same_host)) {
                printk(KERN_WARNING
-                       "lockd: couldn't remove all locks held by %s",
+                       "lockd: couldn't remove all locks held by %s\n",
                        host->h_name);
+               BUG();
+       }
 }
 
 /*
- * delete all hosts structs for clients
+ * Remove all locks held for clients
  */
 void
 nlmsvc_invalidate_all(void)
 {
-       struct nlm_host *host;
-       while ((host = nlm_find_client()) != NULL) {
-               nlmsvc_free_host_resources(host);
-               host->h_expires = 0;
-               host->h_killed = 1;
-               nlm_release_host(host);
-       }
+       /* Release all locks held by NFS clients.
+        * Previously, the code would call
+        * nlmsvc_free_host_resources for each client in
+        * turn, which is about as inefficient as it gets.
+        * Now we just do it once in nlm_traverse_files.
+        */
+       nlm_traverse_files(NULL, nlmsvc_is_client);
 }