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Diffstat (limited to 'fs/ocfs2/dlm/dlmfs.c')
-rw-r--r--fs/ocfs2/dlm/dlmfs.c640
1 files changed, 640 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmfs.c b/fs/ocfs2/dlm/dlmfs.c
new file mode 100644
index 00000000000..dd2d24dc25e
--- /dev/null
+++ b/fs/ocfs2/dlm/dlmfs.c
@@ -0,0 +1,640 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * dlmfs.c
+ *
+ * Code which implements the kernel side of a minimal userspace
+ * interface to our DLM. This file handles the virtual file system
+ * used for communication with userspace. Credit should go to ramfs,
+ * which was a template for the fs side of this module.
+ *
+ * Copyright (C) 2003, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+/* Simple VFS hooks based on: */
+/*
+ * Resizable simple ram filesystem for Linux.
+ *
+ * Copyright (C) 2000 Linus Torvalds.
+ * 2000 Transmeta Corp.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+
+#include <asm/uaccess.h>
+
+
+#include "cluster/nodemanager.h"
+#include "cluster/heartbeat.h"
+#include "cluster/tcp.h"
+
+#include "dlmapi.h"
+
+#include "userdlm.h"
+
+#include "dlmfsver.h"
+
+#define MLOG_MASK_PREFIX ML_DLMFS
+#include "cluster/masklog.h"
+
+static struct super_operations dlmfs_ops;
+static struct file_operations dlmfs_file_operations;
+static struct inode_operations dlmfs_dir_inode_operations;
+static struct inode_operations dlmfs_root_inode_operations;
+static struct inode_operations dlmfs_file_inode_operations;
+static kmem_cache_t *dlmfs_inode_cache;
+
+struct workqueue_struct *user_dlm_worker;
+
+/*
+ * decodes a set of open flags into a valid lock level and a set of flags.
+ * returns < 0 if we have invalid flags
+ * flags which mean something to us:
+ * O_RDONLY -> PRMODE level
+ * O_WRONLY -> EXMODE level
+ *
+ * O_NONBLOCK -> LKM_NOQUEUE
+ */
+static int dlmfs_decode_open_flags(int open_flags,
+ int *level,
+ int *flags)
+{
+ if (open_flags & (O_WRONLY|O_RDWR))
+ *level = LKM_EXMODE;
+ else
+ *level = LKM_PRMODE;
+
+ *flags = 0;
+ if (open_flags & O_NONBLOCK)
+ *flags |= LKM_NOQUEUE;
+
+ return 0;
+}
+
+static int dlmfs_file_open(struct inode *inode,
+ struct file *file)
+{
+ int status, level, flags;
+ struct dlmfs_filp_private *fp = NULL;
+ struct dlmfs_inode_private *ip;
+
+ if (S_ISDIR(inode->i_mode))
+ BUG();
+
+ mlog(0, "open called on inode %lu, flags 0x%x\n", inode->i_ino,
+ file->f_flags);
+
+ status = dlmfs_decode_open_flags(file->f_flags, &level, &flags);
+ if (status < 0)
+ goto bail;
+
+ /* We don't want to honor O_APPEND at read/write time as it
+ * doesn't make sense for LVB writes. */
+ file->f_flags &= ~O_APPEND;
+
+ fp = kmalloc(sizeof(*fp), GFP_KERNEL);
+ if (!fp) {
+ status = -ENOMEM;
+ goto bail;
+ }
+ fp->fp_lock_level = level;
+
+ ip = DLMFS_I(inode);
+
+ status = user_dlm_cluster_lock(&ip->ip_lockres, level, flags);
+ if (status < 0) {
+ /* this is a strange error to return here but I want
+ * to be able userspace to be able to distinguish a
+ * valid lock request from one that simply couldn't be
+ * granted. */
+ if (flags & LKM_NOQUEUE && status == -EAGAIN)
+ status = -ETXTBSY;
+ kfree(fp);
+ goto bail;
+ }
+
+ file->private_data = fp;
+bail:
+ return status;
+}
+
+static int dlmfs_file_release(struct inode *inode,
+ struct file *file)
+{
+ int level, status;
+ struct dlmfs_inode_private *ip = DLMFS_I(inode);
+ struct dlmfs_filp_private *fp =
+ (struct dlmfs_filp_private *) file->private_data;
+
+ if (S_ISDIR(inode->i_mode))
+ BUG();
+
+ mlog(0, "close called on inode %lu\n", inode->i_ino);
+
+ status = 0;
+ if (fp) {
+ level = fp->fp_lock_level;
+ if (level != LKM_IVMODE)
+ user_dlm_cluster_unlock(&ip->ip_lockres, level);
+
+ kfree(fp);
+ file->private_data = NULL;
+ }
+
+ return 0;
+}
+
+static ssize_t dlmfs_file_read(struct file *filp,
+ char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ int bytes_left;
+ ssize_t readlen;
+ char *lvb_buf;
+ struct inode *inode = filp->f_dentry->d_inode;
+
+ mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
+ inode->i_ino, count, *ppos);
+
+ if (*ppos >= i_size_read(inode))
+ return 0;
+
+ if (!count)
+ return 0;
+
+ if (!access_ok(VERIFY_WRITE, buf, count))
+ return -EFAULT;
+
+ /* don't read past the lvb */
+ if ((count + *ppos) > i_size_read(inode))
+ readlen = i_size_read(inode) - *ppos;
+ else
+ readlen = count - *ppos;
+
+ lvb_buf = kmalloc(readlen, GFP_KERNEL);
+ if (!lvb_buf)
+ return -ENOMEM;
+
+ user_dlm_read_lvb(inode, lvb_buf, readlen);
+ bytes_left = __copy_to_user(buf, lvb_buf, readlen);
+ readlen -= bytes_left;
+
+ kfree(lvb_buf);
+
+ *ppos = *ppos + readlen;
+
+ mlog(0, "read %zd bytes\n", readlen);
+ return readlen;
+}
+
+static ssize_t dlmfs_file_write(struct file *filp,
+ const char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ int bytes_left;
+ ssize_t writelen;
+ char *lvb_buf;
+ struct inode *inode = filp->f_dentry->d_inode;
+
+ mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
+ inode->i_ino, count, *ppos);
+
+ if (*ppos >= i_size_read(inode))
+ return -ENOSPC;
+
+ if (!count)
+ return 0;
+
+ if (!access_ok(VERIFY_READ, buf, count))
+ return -EFAULT;
+
+ /* don't write past the lvb */
+ if ((count + *ppos) > i_size_read(inode))
+ writelen = i_size_read(inode) - *ppos;
+ else
+ writelen = count - *ppos;
+
+ lvb_buf = kmalloc(writelen, GFP_KERNEL);
+ if (!lvb_buf)
+ return -ENOMEM;
+
+ bytes_left = copy_from_user(lvb_buf, buf, writelen);
+ writelen -= bytes_left;
+ if (writelen)
+ user_dlm_write_lvb(inode, lvb_buf, writelen);
+
+ kfree(lvb_buf);
+
+ *ppos = *ppos + writelen;
+ mlog(0, "wrote %zd bytes\n", writelen);
+ return writelen;
+}
+
+static void dlmfs_init_once(void *foo,
+ kmem_cache_t *cachep,
+ unsigned long flags)
+{
+ struct dlmfs_inode_private *ip =
+ (struct dlmfs_inode_private *) foo;
+
+ if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+ SLAB_CTOR_CONSTRUCTOR) {
+ ip->ip_dlm = NULL;
+ ip->ip_parent = NULL;
+
+ inode_init_once(&ip->ip_vfs_inode);
+ }
+}
+
+static struct inode *dlmfs_alloc_inode(struct super_block *sb)
+{
+ struct dlmfs_inode_private *ip;
+
+ ip = kmem_cache_alloc(dlmfs_inode_cache, SLAB_NOFS);
+ if (!ip)
+ return NULL;
+
+ return &ip->ip_vfs_inode;
+}
+
+static void dlmfs_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
+}
+
+static void dlmfs_clear_inode(struct inode *inode)
+{
+ int status;
+ struct dlmfs_inode_private *ip;
+
+ if (!inode)
+ return;
+
+ mlog(0, "inode %lu\n", inode->i_ino);
+
+ ip = DLMFS_I(inode);
+
+ if (S_ISREG(inode->i_mode)) {
+ status = user_dlm_destroy_lock(&ip->ip_lockres);
+ if (status < 0)
+ mlog_errno(status);
+ iput(ip->ip_parent);
+ goto clear_fields;
+ }
+
+ mlog(0, "we're a directory, ip->ip_dlm = 0x%p\n", ip->ip_dlm);
+ /* we must be a directory. If required, lets unregister the
+ * dlm context now. */
+ if (ip->ip_dlm)
+ user_dlm_unregister_context(ip->ip_dlm);
+clear_fields:
+ ip->ip_parent = NULL;
+ ip->ip_dlm = NULL;
+}
+
+static struct backing_dev_info dlmfs_backing_dev_info = {
+ .ra_pages = 0, /* No readahead */
+ .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+};
+
+static struct inode *dlmfs_get_root_inode(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+ int mode = S_IFDIR | 0755;
+ struct dlmfs_inode_private *ip;
+
+ if (inode) {
+ ip = DLMFS_I(inode);
+
+ inode->i_mode = mode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_nlink++;
+
+ inode->i_fop = &simple_dir_operations;
+ inode->i_op = &dlmfs_root_inode_operations;
+ }
+
+ return inode;
+}
+
+static struct inode *dlmfs_get_inode(struct inode *parent,
+ struct dentry *dentry,
+ int mode)
+{
+ struct super_block *sb = parent->i_sb;
+ struct inode * inode = new_inode(sb);
+ struct dlmfs_inode_private *ip;
+
+ if (!inode)
+ return NULL;
+
+ inode->i_mode = mode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+
+ ip = DLMFS_I(inode);
+ ip->ip_dlm = DLMFS_I(parent)->ip_dlm;
+
+ switch (mode & S_IFMT) {
+ default:
+ /* for now we don't support anything other than
+ * directories and regular files. */
+ BUG();
+ break;
+ case S_IFREG:
+ inode->i_op = &dlmfs_file_inode_operations;
+ inode->i_fop = &dlmfs_file_operations;
+
+ i_size_write(inode, DLM_LVB_LEN);
+
+ user_dlm_lock_res_init(&ip->ip_lockres, dentry);
+
+ /* released at clear_inode time, this insures that we
+ * get to drop the dlm reference on each lock *before*
+ * we call the unregister code for releasing parent
+ * directories. */
+ ip->ip_parent = igrab(parent);
+ BUG_ON(!ip->ip_parent);
+ break;
+ case S_IFDIR:
+ inode->i_op = &dlmfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink ==
+ * 2 (for "." entry) */
+ inode->i_nlink++;
+ break;
+ }
+
+ if (parent->i_mode & S_ISGID) {
+ inode->i_gid = parent->i_gid;
+ if (S_ISDIR(mode))
+ inode->i_mode |= S_ISGID;
+ }
+
+ return inode;
+}
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+/* SMP-safe */
+static int dlmfs_mkdir(struct inode * dir,
+ struct dentry * dentry,
+ int mode)
+{
+ int status;
+ struct inode *inode = NULL;
+ struct qstr *domain = &dentry->d_name;
+ struct dlmfs_inode_private *ip;
+ struct dlm_ctxt *dlm;
+
+ mlog(0, "mkdir %.*s\n", domain->len, domain->name);
+
+ /* verify that we have a proper domain */
+ if (domain->len >= O2NM_MAX_NAME_LEN) {
+ status = -EINVAL;
+ mlog(ML_ERROR, "invalid domain name for directory.\n");
+ goto bail;
+ }
+
+ inode = dlmfs_get_inode(dir, dentry, mode | S_IFDIR);
+ if (!inode) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ ip = DLMFS_I(inode);
+
+ dlm = user_dlm_register_context(domain);
+ if (IS_ERR(dlm)) {
+ status = PTR_ERR(dlm);
+ mlog(ML_ERROR, "Error %d could not register domain \"%.*s\"\n",
+ status, domain->len, domain->name);
+ goto bail;
+ }
+ ip->ip_dlm = dlm;
+
+ dir->i_nlink++;
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
+
+ status = 0;
+bail:
+ if (status < 0)
+ iput(inode);
+ return status;
+}
+
+static int dlmfs_create(struct inode *dir,
+ struct dentry *dentry,
+ int mode,
+ struct nameidata *nd)
+{
+ int status = 0;
+ struct inode *inode;
+ struct qstr *name = &dentry->d_name;
+
+ mlog(0, "create %.*s\n", name->len, name->name);
+
+ /* verify name is valid and doesn't contain any dlm reserved
+ * characters */
+ if (name->len >= USER_DLM_LOCK_ID_MAX_LEN ||
+ name->name[0] == '$') {
+ status = -EINVAL;
+ mlog(ML_ERROR, "invalid lock name, %.*s\n", name->len,
+ name->name);
+ goto bail;
+ }
+
+ inode = dlmfs_get_inode(dir, dentry, mode | S_IFREG);
+ if (!inode) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
+bail:
+ return status;
+}
+
+static int dlmfs_unlink(struct inode *dir,
+ struct dentry *dentry)
+{
+ int status;
+ struct inode *inode = dentry->d_inode;
+
+ mlog(0, "unlink inode %lu\n", inode->i_ino);
+
+ /* if there are no current holders, or none that are waiting
+ * to acquire a lock, this basically destroys our lockres. */
+ status = user_dlm_destroy_lock(&DLMFS_I(inode)->ip_lockres);
+ if (status < 0) {
+ mlog(ML_ERROR, "unlink %.*s, error %d from destroy\n",
+ dentry->d_name.len, dentry->d_name.name, status);
+ goto bail;
+ }
+ status = simple_unlink(dir, dentry);
+bail:
+ return status;
+}
+
+static int dlmfs_fill_super(struct super_block * sb,
+ void * data,
+ int silent)
+{
+ struct inode * inode;
+ struct dentry * root;
+
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = DLMFS_MAGIC;
+ sb->s_op = &dlmfs_ops;
+ inode = dlmfs_get_root_inode(sb);
+ if (!inode)
+ return -ENOMEM;
+
+ root = d_alloc_root(inode);
+ if (!root) {
+ iput(inode);
+ return -ENOMEM;
+ }
+ sb->s_root = root;
+ return 0;
+}
+
+static struct file_operations dlmfs_file_operations = {
+ .open = dlmfs_file_open,
+ .release = dlmfs_file_release,
+ .read = dlmfs_file_read,
+ .write = dlmfs_file_write,
+};
+
+static struct inode_operations dlmfs_dir_inode_operations = {
+ .create = dlmfs_create,
+ .lookup = simple_lookup,
+ .unlink = dlmfs_unlink,
+};
+
+/* this way we can restrict mkdir to only the toplevel of the fs. */
+static struct inode_operations dlmfs_root_inode_operations = {
+ .lookup = simple_lookup,
+ .mkdir = dlmfs_mkdir,
+ .rmdir = simple_rmdir,
+};
+
+static struct super_operations dlmfs_ops = {
+ .statfs = simple_statfs,
+ .alloc_inode = dlmfs_alloc_inode,
+ .destroy_inode = dlmfs_destroy_inode,
+ .clear_inode = dlmfs_clear_inode,
+ .drop_inode = generic_delete_inode,
+};
+
+static struct inode_operations dlmfs_file_inode_operations = {
+ .getattr = simple_getattr,
+};
+
+static struct super_block *dlmfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return get_sb_nodev(fs_type, flags, data, dlmfs_fill_super);
+}
+
+static struct file_system_type dlmfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "ocfs2_dlmfs",
+ .get_sb = dlmfs_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static int __init init_dlmfs_fs(void)
+{
+ int status;
+ int cleanup_inode = 0, cleanup_worker = 0;
+
+ dlmfs_print_version();
+
+ dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache",
+ sizeof(struct dlmfs_inode_private),
+ 0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
+ dlmfs_init_once, NULL);
+ if (!dlmfs_inode_cache)
+ return -ENOMEM;
+ cleanup_inode = 1;
+
+ user_dlm_worker = create_singlethread_workqueue("user_dlm");
+ if (!user_dlm_worker) {
+ status = -ENOMEM;
+ goto bail;
+ }
+ cleanup_worker = 1;
+
+ status = register_filesystem(&dlmfs_fs_type);
+bail:
+ if (status) {
+ if (cleanup_inode)
+ kmem_cache_destroy(dlmfs_inode_cache);
+ if (cleanup_worker)
+ destroy_workqueue(user_dlm_worker);
+ } else
+ printk("OCFS2 User DLM kernel interface loaded\n");
+ return status;
+}
+
+static void __exit exit_dlmfs_fs(void)
+{
+ unregister_filesystem(&dlmfs_fs_type);
+
+ flush_workqueue(user_dlm_worker);
+ destroy_workqueue(user_dlm_worker);
+
+ if (kmem_cache_destroy(dlmfs_inode_cache))
+ printk(KERN_INFO "dlmfs_inode_cache: not all structures "
+ "were freed\n");
+}
+
+MODULE_AUTHOR("Oracle");
+MODULE_LICENSE("GPL");
+
+module_init(init_dlmfs_fs)
+module_exit(exit_dlmfs_fs)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-14 01:54:17 +0000