From 53fc622b9e829c8e632e45ef8c14f054388759c1 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Thu, 20 Dec 2007 16:49:04 -0800 Subject: [PATCH] [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: Mark Fasheh --- Documentation/filesystems/ocfs2.txt | 1 + fs/ocfs2/Makefile | 1 + fs/ocfs2/file.c | 60 ++++++++++++- fs/ocfs2/locks.c | 125 ++++++++++++++++++++++++++++ fs/ocfs2/locks.h | 31 +++++++ fs/ocfs2/ocfs2.h | 1 + fs/ocfs2/super.c | 19 +++++ 7 files changed, 237 insertions(+), 1 deletion(-) create mode 100644 fs/ocfs2/locks.c create mode 100644 fs/ocfs2/locks.h diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt index 071fad137e..c318a8bbb1 100644 --- a/Documentation/filesystems/ocfs2.txt +++ b/Documentation/filesystems/ocfs2.txt @@ -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. diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile index 3591890b32..4d4ce48bb4 100644 --- a/fs/ocfs2/Makefile +++ b/fs/ocfs2/Makefile @@ -19,6 +19,7 @@ ocfs2-objs := \ ioctl.o \ journal.o \ localalloc.o \ + locks.o \ mmap.o \ namei.o \ resize.o \ diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 432e5f3c47..caefd57178 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -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, }; diff --git a/fs/ocfs2/locks.c b/fs/ocfs2/locks.c new file mode 100644 index 0000000000..203f871438 --- /dev/null +++ b/fs/ocfs2/locks.c @@ -0,0 +1,125 @@ +/* -*- 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 + +#define MLOG_MASK_PREFIX ML_INODE +#include + +#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); +} diff --git a/fs/ocfs2/locks.h b/fs/ocfs2/locks.h new file mode 100644 index 0000000000..9743ef2324 --- /dev/null +++ b/fs/ocfs2/locks.h @@ -0,0 +1,31 @@ +/* -*- 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 */ diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 63c131e1cc..22e334d125 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.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 diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 1104f14c31..4a091f5866 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -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; } -- 2.39.5