1 files changed, 309 insertions, 0 deletions

diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
new file mode 100644
index 000000000000..de7536358c7c
--- /dev/null
+++ b/fs/lockd/svcsubs.c
@@ -0,0 +1,309 @@
+/*
+ * linux/fs/lockd/svcsubs.c
+ *
+ * Various support routines for the NLM server.
+ *
+ * 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/sunrpc/svc.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfsd/nfsfh.h>
+#include <linux/nfsd/export.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/share.h>
+#include <linux/lockd/sm_inter.h>
+
+#define NLMDBG_FACILITY         NLMDBG_SVCSUBS
+
+
+/*
+ * Global file hash table
+ */
+#define FILE_HASH_BITS          5
+#define FILE_NRHASH             (1<<FILE_HASH_BITS)
+static struct nlm_file *        nlm_files[FILE_NRHASH];
+static DECLARE_MUTEX(nlm_file_sema);
+
+static inline unsigned int file_hash(struct nfs_fh *f)
+{
+        unsigned int tmp=0;
+        int i;
+        for (i=0; i<NFS2_FHSIZE;i++)
+                tmp += f->data[i];
+        return tmp & (FILE_NRHASH - 1);
+}
+
+/*
+ * Lookup file info. If it doesn't exist, create a file info struct
+ * and open a (VFS) file for the given inode.
+ *
+ * FIXME:
+ * Note that we open the file O_RDONLY even when creating write locks.
+ * This is not quite right, but for now, we assume the client performs
+ * the proper R/W checking.
+ */
+u32
+nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
+                                        struct nfs_fh *f)
+{
+        struct nlm_file *file;
+        unsigned int    hash;
+        u32             nfserr;
+        u32             *fhp = (u32*)f->data;
+
+        dprintk("lockd: nlm_file_lookup(%08x %08x %08x %08x %08x %08x)\n",
+                fhp[0], fhp[1], fhp[2], fhp[3], fhp[4], fhp[5]);
+
+
+        hash = file_hash(f);
+
+        /* Lock file table */
+        down(&nlm_file_sema);
+
+        for (file = nlm_files[hash]; file; file = file->f_next)
+                if (!nfs_compare_fh(&file->f_handle, f))
+                        goto found;
+
+        dprintk("lockd: creating file for (%08x %08x %08x %08x %08x %08x)\n",
+                fhp[0], fhp[1], fhp[2], fhp[3], fhp[4], fhp[5]);
+
+        nfserr = nlm_lck_denied_nolocks;
+        file = (struct nlm_file *) kmalloc(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);
+
+        /* Open the file. Note that this must not sleep for too long, else
+         * we would lock up lockd:-) So no NFS re-exports, folks.
+         *
+         * We have to make sure we have the right credential to open
+         * the file.
+         */
+        if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
+                dprintk("lockd: open failed (nfserr %d)\n", ntohl(nfserr));
+                goto out_free;
+        }
+
+        file->f_next = nlm_files[hash];
+        nlm_files[hash] = file;
+
+found:
+        dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
+        *result = file;
+        file->f_count++;
+        nfserr = 0;
+
+out_unlock:
+        up(&nlm_file_sema);
+        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;
+}
+
+/*
+ * Delete a file after having released all locks, blocks and shares
+ */
+static inline void
+nlm_delete_file(struct nlm_file *file)
+{
+        struct inode *inode = file->f_file->f_dentry->d_inode;
+        struct nlm_file **fp, *f;
+
+        dprintk("lockd: closing file %s/%ld\n",
+                inode->i_sb->s_id, inode->i_ino);
+        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;
+        }
+
+        printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
+}
+
+/*
+ * Loop over all locks on the given file and perform the specified
+ * action.
+ */
+static int
+nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file, int action)
+{
+        struct inode     *inode = nlmsvc_file_inode(file);
+        struct file_lock *fl;
+        struct nlm_host  *lockhost;
+
+again:
+        file->f_locks = 0;
+        for (fl = inode->i_flock; fl; fl = fl->fl_next) {
+                if (!(fl->fl_flags & FL_LOCKD))
+                        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) {
+                        struct file_lock lock = *fl;
+
+                        if (host && lockhost != host)
+                                continue;
+
+                        lock.fl_type  = F_UNLCK;
+                        lock.fl_start = 0;
+                        lock.fl_end   = OFFSET_MAX;
+                        if (posix_lock_file(file->f_file, &lock) < 0) {
+                                printk("lockd: unlock failure in %s:%d\n",
+                                                __FILE__, __LINE__);
+                                return 1;
+                        }
+                        goto again;
+                }
+        }
+
+        return 0;
+}
+
+/*
+ * Operate on a single file
+ */
+static inline int
+nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, int action)
+{
+        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))
+                        return 1;
+        }
+        return nlm_traverse_locks(host, file, action);
+}
+
+/*
+ * Loop over all files in the file table.
+ */
+static int
+nlm_traverse_files(struct nlm_host *host, int action)
+{
+        struct nlm_file *file, **fp;
+        int             i;
+
+        down(&nlm_file_sema);
+        for (i = 0; i < FILE_NRHASH; i++) {
+                fp = nlm_files + i;
+                while ((file = *fp) != NULL) {
+                        /* 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;
+                        }
+
+                        /* No more references to this file. Let go of it. */
+                        if (!file->f_blocks && !file->f_locks
+                         && !file->f_shares && !file->f_count) {
+                                *fp = file->f_next;
+                                nlmsvc_ops->fclose(file->f_file);
+                                kfree(file);
+                        } else {
+                                fp = &file->f_next;
+                        }
+                }
+        }
+        up(&nlm_file_sema);
+        return 0;
+}
+
+/*
+ * Release file. If there are no more remote locks on this file,
+ * close it and free the handle.
+ *
+ * Note that we can't do proper reference counting without major
+ * contortions because the code in fs/locks.c creates, deletes and
+ * splits locks without notification. Our only way is to walk the
+ * entire lock list each time we remove a lock.
+ */
+void
+nlm_release_file(struct nlm_file *file)
+{
+        dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
+                                file, file->f_count);
+
+        /* Lock file table */
+        down(&nlm_file_sema);
+
+        /* 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);
+        }
+
+        up(&nlm_file_sema);
+}
+
+/*
+ * Mark all hosts that still hold resources
+ */
+void
+nlmsvc_mark_resources(void)
+{
+        dprintk("lockd: nlmsvc_mark_resources\n");
+
+        nlm_traverse_files(NULL, NLM_ACT_MARK);
+}
+
+/*
+ * Release all resources held by the given client
+ */
+void
+nlmsvc_free_host_resources(struct nlm_host *host)
+{
+        dprintk("lockd: nlmsvc_free_host_resources\n");
+
+        if (nlm_traverse_files(host, NLM_ACT_UNLOCK))
+                printk(KERN_WARNING
+                        "lockd: couldn't remove all locks held by %s",
+                        host->h_name);
+}
+
+/*
+ * delete all hosts structs 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);
+        }
+}