Commit 53fc622b authored by Mark Fasheh's avatar Mark Fasheh
Browse files

[PATCH 2/2] ocfs2: cluster aware flock()



Hook up ocfs2_flock(), using the new flock lock type in dlmglue.c. A new
mount option, "localflocks" is added so that users can revert to old
functionality as need be.
Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent cf8e06f1
......@@ -75,3 +75,4 @@ commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata
localalloc=8(*) Allows custom localalloc size in MB. If the value is too
large, the fs will silently revert it to the default.
Localalloc is not enabled for local mounts.
localflocks This disables cluster aware flock.
......@@ -19,6 +19,7 @@ ocfs2-objs := \
ioctl.o \
journal.o \
localalloc.o \
locks.o \
mmap.o \
namei.o \
resize.o \
......
......@@ -51,6 +51,7 @@
#include "inode.h"
#include "ioctl.h"
#include "journal.h"
#include "locks.h"
#include "mmap.h"
#include "suballoc.h"
#include "super.h"
......@@ -63,6 +64,35 @@ static int ocfs2_sync_inode(struct inode *inode)
return sync_mapping_buffers(inode->i_mapping);
}
static int ocfs2_init_file_private(struct inode *inode, struct file *file)
{
struct ocfs2_file_private *fp;
fp = kzalloc(sizeof(struct ocfs2_file_private), GFP_KERNEL);
if (!fp)
return -ENOMEM;
fp->fp_file = file;
mutex_init(&fp->fp_mutex);
ocfs2_file_lock_res_init(&fp->fp_flock, fp);
file->private_data = fp;
return 0;
}
static void ocfs2_free_file_private(struct inode *inode, struct file *file)
{
struct ocfs2_file_private *fp = file->private_data;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (fp) {
ocfs2_simple_drop_lockres(osb, &fp->fp_flock);
ocfs2_lock_res_free(&fp->fp_flock);
kfree(fp);
file->private_data = NULL;
}
}
static int ocfs2_file_open(struct inode *inode, struct file *file)
{
int status;
......@@ -89,7 +119,18 @@ static int ocfs2_file_open(struct inode *inode, struct file *file)
oi->ip_open_count++;
spin_unlock(&oi->ip_lock);
status = 0;
status = ocfs2_init_file_private(inode, file);
if (status) {
/*
* We want to set open count back if we're failing the
* open.
*/
spin_lock(&oi->ip_lock);
oi->ip_open_count--;
spin_unlock(&oi->ip_lock);
}
leave:
mlog_exit(status);
return status;
......@@ -108,11 +149,24 @@ static int ocfs2_file_release(struct inode *inode, struct file *file)
oi->ip_flags &= ~OCFS2_INODE_OPEN_DIRECT;
spin_unlock(&oi->ip_lock);
ocfs2_free_file_private(inode, file);
mlog_exit(0);
return 0;
}
static int ocfs2_dir_open(struct inode *inode, struct file *file)
{
return ocfs2_init_file_private(inode, file);
}
static int ocfs2_dir_release(struct inode *inode, struct file *file)
{
ocfs2_free_file_private(inode, file);
return 0;
}
static int ocfs2_sync_file(struct file *file,
struct dentry *dentry,
int datasync)
......@@ -2191,6 +2245,7 @@ const struct file_operations ocfs2_fops = {
#ifdef CONFIG_COMPAT
.compat_ioctl = ocfs2_compat_ioctl,
#endif
.flock = ocfs2_flock,
.splice_read = ocfs2_file_splice_read,
.splice_write = ocfs2_file_splice_write,
};
......@@ -2199,8 +2254,11 @@ const struct file_operations ocfs2_dops = {
.read = generic_read_dir,
.readdir = ocfs2_readdir,
.fsync = ocfs2_sync_file,
.release = ocfs2_dir_release,
.open = ocfs2_dir_open,
.ioctl = ocfs2_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ocfs2_compat_ioctl,
#endif
.flock = ocfs2_flock,
};
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* locks.c
*
* Userspace file locking support
*
* Copyright (C) 2007 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.
*/
#include <linux/fs.h>
#define MLOG_MASK_PREFIX ML_INODE
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "dlmglue.h"
#include "file.h"
#include "locks.h"
static int ocfs2_do_flock(struct file *file, struct inode *inode,
int cmd, struct file_lock *fl)
{
int ret = 0, level = 0, trylock = 0;
struct ocfs2_file_private *fp = file->private_data;
struct ocfs2_lock_res *lockres = &fp->fp_flock;
if (fl->fl_type == F_WRLCK)
level = 1;
if (!IS_SETLKW(cmd))
trylock = 1;
mutex_lock(&fp->fp_mutex);
if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
lockres->l_level > LKM_NLMODE) {
int old_level = 0;
if (lockres->l_level == LKM_EXMODE)
old_level = 1;
if (level == old_level)
goto out;
/*
* Converting an existing lock is not guaranteed to be
* atomic, so we can get away with simply unlocking
* here and allowing the lock code to try at the new
* level.
*/
flock_lock_file_wait(file,
&(struct file_lock){.fl_type = F_UNLCK});
ocfs2_file_unlock(file);
}
ret = ocfs2_file_lock(file, level, trylock);
if (ret) {
if (ret == -EAGAIN && trylock)
ret = -EWOULDBLOCK;
else
mlog_errno(ret);
goto out;
}
ret = flock_lock_file_wait(file, fl);
out:
mutex_unlock(&fp->fp_mutex);
return ret;
}
static int ocfs2_do_funlock(struct file *file, int cmd, struct file_lock *fl)
{
int ret;
struct ocfs2_file_private *fp = file->private_data;
mutex_lock(&fp->fp_mutex);
ocfs2_file_unlock(file);
ret = flock_lock_file_wait(file, fl);
mutex_unlock(&fp->fp_mutex);
return ret;
}
/*
* Overall flow of ocfs2_flock() was influenced by gfs2_flock().
*/
int ocfs2_flock(struct file *file, int cmd, struct file_lock *fl)
{
struct inode *inode = file->f_mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (!(fl->fl_flags & FL_FLOCK))
return -ENOLCK;
if (__mandatory_lock(inode))
return -ENOLCK;
if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) ||
ocfs2_mount_local(osb))
return flock_lock_file_wait(file, fl);
if (fl->fl_type == F_UNLCK)
return ocfs2_do_funlock(file, cmd, fl);
else
return ocfs2_do_flock(file, inode, cmd, fl);
}
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* locks.h
*
* Function prototypes for Userspace file locking support
*
* Copyright (C) 2002, 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.
*/
#ifndef OCFS2_LOCKS_H
#define OCFS2_LOCKS_H
int ocfs2_flock(struct file *file, int cmd, struct file_lock *fl);
#endif /* OCFS2_LOCKS_H */
......@@ -171,6 +171,7 @@ enum ocfs2_mount_options
OCFS2_MOUNT_NOINTR = 1 << 2, /* Don't catch signals */
OCFS2_MOUNT_ERRORS_PANIC = 1 << 3, /* Panic on errors */
OCFS2_MOUNT_DATA_WRITEBACK = 1 << 4, /* No data ordering */
OCFS2_MOUNT_LOCALFLOCKS = 1 << 5, /* No cluster aware user file locks */
};
#define OCFS2_OSB_SOFT_RO 0x0001
......
......@@ -153,6 +153,7 @@ enum {
Opt_slot,
Opt_commit,
Opt_localalloc,
Opt_localflocks,
Opt_err,
};
......@@ -170,6 +171,7 @@ static match_table_t tokens = {
{Opt_slot, "preferred_slot=%u"},
{Opt_commit, "commit=%u"},
{Opt_localalloc, "localalloc=%d"},
{Opt_localflocks, "localflocks"},
{Opt_err, NULL}
};
......@@ -848,6 +850,20 @@ static int ocfs2_parse_options(struct super_block *sb,
if (option >= 0 && (option <= ocfs2_local_alloc_size(sb) * 8))
mopt->localalloc_opt = option;
break;
case Opt_localflocks:
/*
* Changing this during remount could race
* flock() requests, or "unbalance" existing
* ones (e.g., a lock is taken in one mode but
* dropped in the other). If users care enough
* to flip locking modes during remount, we
* could add a "local" flag to individual
* flock structures for proper tracking of
* state.
*/
if (!is_remount)
mopt->mount_opt |= OCFS2_MOUNT_LOCALFLOCKS;
break;
default:
mlog(ML_ERROR,
"Unrecognized mount option \"%s\" "
......@@ -903,6 +919,9 @@ static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
if (osb->local_alloc_size != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
seq_printf(s, ",localalloc=%d", osb->local_alloc_size);
if (opts & OCFS2_MOUNT_LOCALFLOCKS)
seq_printf(s, ",localflocks,");
return 0;
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment