On Thursday, October 11, 2001 06:43:23 PM +0200 wrote:
> Hi!
>
> Will there be a VFS lock patch for 2.4.12? The patch for 2.4.9 doesn't
> work with kernels > 2.4.10
I'd like to clean this up a little so the extra semaphore isn't required,
but it does work. There's an extra hunk tacked onto the end that you'll
need for reiserfs.
-chris
Index: 0.22/fs/super.c
--- 0.22/fs/super.c Tue, 09 Oct 2001 09:52:53 -0400 root (linux/d/45_super.c 1.1.2.1.3.1 644)
+++ 0.23/fs/super.c Tue, 09 Oct 2001 09:59:03 -0400 root (linux/d/45_super.c 1.1.2.1.3.2 644)
@@ -54,6 +54,8 @@
LIST_HEAD(super_blocks);
spinlock_t sb_lock = SPIN_LOCK_UNLOCKED;
+static DECLARE_MUTEX(lockfs_sem);
+
/*
* Handling of filesystem drivers list.
* Rules:
@@ -322,6 +324,19 @@
sb->s_op->write_super(sb);
unlock_super(sb);
}
+
+static inline void write_super_lockfs(struct super_block *sb)
+{
+ lock_super(sb);
+ if (sb->s_root && sb->s_op) {
+ if (sb->s_dirt && sb->s_op->write_super)
+ sb->s_op->write_super(sb);
+ if (sb->s_op->write_super_lockfs) {
+ sb->s_op->write_super_lockfs(sb);
+ }
+ }
+ unlock_super(sb);
+}
/*
* Note: check the dirty flag before waiting, so we don't
@@ -357,6 +372,39 @@
spin_unlock(&sb_lock);
}
+/*
+ * Note: don't check the dirty flag before waiting, we want the lock
+ * to happen every time this is called. dev must be non-zero
+ */
+void sync_supers_lockfs(kdev_t dev)
+{
+ struct super_block * sb;
+
+ down(&lockfs_sem);
+ if (dev) {
+ sb = get_super(dev);
+ if (sb) {
+ write_super_lockfs(sb);
+ drop_super(sb);
+ }
+ }
+}
+
+void unlockfs(kdev_t dev)
+{
+ struct super_block * sb;
+
+ if (dev) {
+ sb = get_super(dev);
+ if (sb) {
+ if (sb->s_op && sb->s_op->unlockfs)
+ sb->s_op->unlockfs(sb) ;
+ drop_super(sb);
+ }
+ }
+ up(&lockfs_sem);
+}
+
/**
* get_super - get the superblock of a device
* @dev: device to get the superblock for
@@ -578,6 +626,7 @@
if (!s)
goto out1;
down_write(&s->s_umount);
+ down(&lockfs_sem) ;
error = -EBUSY;
restart:
@@ -590,11 +639,13 @@
if (old->s_type != fs_type ||
((flags ^ old->s_flags) & MS_RDONLY)) {
spin_unlock(&sb_lock);
+ up(&lockfs_sem);
put_super(s);
goto out1;
}
if (!grab_super(old))
goto restart;
+ up(&lockfs_sem);
put_super(s);
blkdev_put(bdev, BDEV_FS);
path_release(&nd);
@@ -615,6 +666,9 @@
if (!fs_type->read_super(s, data, 0))
goto out_fail;
unlock_super(s);
+
+ up(&lockfs_sem);
+
get_filesystem(fs_type);
path_release(&nd);
return s;
@@ -728,6 +782,7 @@
sb->s_count -= S_BIAS;
spin_unlock(&sb_lock);
+ down(&lockfs_sem);
down_write(&sb->s_umount);
lock_kernel();
sb->s_root = NULL;
@@ -744,6 +799,7 @@
if (sop->put_super)
sop->put_super(sb);
}
+ up(&lockfs_sem);
/* Forget any remaining inodes */
if (invalidate_inodes(sb)) {
Index: 0.22/fs/buffer.c
--- 0.22/fs/buffer.c Tue, 09 Oct 2001 09:52:53 -0400 root (linux/i/46_buffer.c 1.1.2.1.8.1 644)
+++ 0.23/fs/buffer.c Tue, 09 Oct 2001 09:59:03 -0400 root (linux/i/46_buffer.c 1.1.2.1.8.2 644)
@@ -359,6 +359,34 @@
fsync_dev(dev);
}
+int fsync_dev_lockfs(kdev_t dev)
+{
+ /* you are not allowed to try locking all the filesystems
+ ** on the system, your chances of getting through without
+ ** total deadlock are slim to none.
+ */
+ if (!dev)
+ return fsync_dev(dev) ;
+
+ sync_buffers(dev, 0);
+
+ lock_kernel();
+ /* note, the FS might need to start transactions to
+ ** sync the inodes, or the quota, no locking until
+ ** after these are done
+ */
+ sync_inodes(dev);
+ DQUOT_SYNC(dev);
+ /* if inodes or quotas could be dirtied during the
+ ** sync_supers_lockfs call, the FS is responsible for getting
+ ** them on disk, without deadlocking against the lock
+ */
+ sync_supers_lockfs(dev) ;
+ unlock_kernel();
+
+ return sync_buffers(dev, 1) ;
+}
+
asmlinkage long sys_sync(void)
{
fsync_dev(0);
Index: 0.22/drivers/md/lvm.c
--- 0.22/drivers/md/lvm.c Tue, 09 Oct 2001 09:56:26 -0400 root (linux/i/c/30_lvm.c 1.1.2.1.3.1 644)
+++ 0.23/drivers/md/lvm.c Tue, 09 Oct 2001 09:59:03 -0400 root (linux/i/c/30_lvm.c 1.1.2.1.3.2 644)
@@ -221,9 +221,6 @@
#define DEVICE_OFF(device)
#define LOCAL_END_REQUEST
-/* lvm_do_lv_create calls fsync_dev_lockfs()/unlockfs() */
-/* #define LVM_VFS_ENHANCEMENT */
-
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
@@ -2129,12 +2126,8 @@
if (lv_ptr->lv_access & LV_SNAPSHOT) {
lv_t *org = lv_ptr->lv_snapshot_org, *last;
- /* sync the original logical volume */
- fsync_dev(org->lv_dev);
-#ifdef LVM_VFS_ENHANCEMENT
/* VFS function call to sync and lock the filesystem */
fsync_dev_lockfs(org->lv_dev);
-#endif
down_write(&org->lv_lock);
org->lv_access |= LV_SNAPSHOT_ORG;
@@ -2159,11 +2152,9 @@
else
set_device_ro(lv_ptr->lv_dev, 1);
-#ifdef LVM_VFS_ENHANCEMENT
/* VFS function call to unlock the filesystem */
if (lv_ptr->lv_access & LV_SNAPSHOT)
unlockfs(lv_ptr->lv_snapshot_org->lv_dev);
-#endif
lvm_gendisk.part[MINOR(lv_ptr->lv_dev)].de = lvm_fs_create_lv(vg_ptr, lv_ptr);
return 0;
Index: 0.22/kernel/ksyms.c
--- 0.22/kernel/ksyms.c Tue, 09 Oct 2001 09:52:53 -0400 root (linux/n/c/22_ksyms.c 1.1.2.1.8.1 644)
+++ 0.23/kernel/ksyms.c Tue, 09 Oct 2001 09:59:03 -0400 root (linux/n/c/22_ksyms.c 1.1.2.1.8.2 644)
@@ -178,6 +178,8 @@
EXPORT_SYMBOL(invalidate_inode_pages);
EXPORT_SYMBOL(truncate_inode_pages);
EXPORT_SYMBOL(fsync_dev);
+EXPORT_SYMBOL(fsync_dev_lockfs);
+EXPORT_SYMBOL(unlockfs);
EXPORT_SYMBOL(fsync_no_super);
EXPORT_SYMBOL(permission);
EXPORT_SYMBOL(vfs_permission);
Index: 0.22/include/linux/fs.h
--- 0.22/include/linux/fs.h Tue, 09 Oct 2001 09:52:53 -0400 root (linux/f/d/9_fs.h 1.1.2.1.9.1 644)
+++ 0.23/include/linux/fs.h Tue, 09 Oct 2001 09:59:03 -0400 root (linux/f/d/9_fs.h 1.1.2.1.9.2 644)
@@ -1183,6 +1183,7 @@
extern int sync_buffers(kdev_t, int);
extern void sync_dev(kdev_t);
extern int fsync_dev(kdev_t);
+extern int fsync_dev_lockfs(kdev_t);
extern int fsync_super(struct super_block *);
extern int fsync_no_super(kdev_t);
extern void sync_inodes_sb(struct super_block *);
@@ -1194,6 +1195,8 @@
extern void filemap_fdatasync(struct address_space *);
extern void filemap_fdatawait(struct address_space *);
extern void sync_supers(kdev_t);
+extern void sync_supers_lockfs(kdev_t);
+extern void unlockfs(kdev_t);
extern int bmap(struct inode *, int);
extern int notify_change(struct dentry *, struct iattr *);
extern int permission(struct inode *, int);
--- linux-2.4.4.tmp/fs/reiserfs/super.c Mon Apr 30 16:01:29 2001
+++ linux-2.4.4.SuSE/fs/reiserfs/super.c Mon Apr 30 16:02:13 2001
@@ -80,7 +80,7 @@
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
reiserfs_block_writes(&th) ;
- journal_end(&th, s, 1) ;
+ journal_end_sync(&th, s, 1) ;
}
s->s_dirt = dirty;
unlock_kernel() ;
