Prev: [patch 02/52] fs: fix superblock iteration race
Next: [patch 24/52] fs: dcache reduce d_parent locking
From: npiggin on 23 Jun 2010 23:20
Protect sb->s_inodes with a new lock, sb_inode_list_lock.

Signed-off-by: Nick Piggin <npiggin(a)suse.de>
---
fs/drop_caches.c | 4 ++++
fs/fs-writeback.c | 4 ++++
fs/inode.c | 12 ++++++++++++
fs/notify/inode_mark.c | 2 ++
fs/notify/inotify/inotify.c | 2 ++
fs/quota/dquot.c | 6 ++++++
include/linux/writeback.h | 1 +
7 files changed, 31 insertions(+)

Index: linux-2.6/fs/drop_caches.c
===================================================================
--- linux-2.6.orig/fs/drop_caches.c
+++ linux-2.6/fs/drop_caches.c
@@ -17,18 +17,22 @@ static void drop_pagecache_sb(struct sup
struct inode *inode, *toput_inode = NULL;

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
continue;
if (inode->i_mapping->nrpages == 0)
continue;
__iget(inode);
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
}
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
iput(toput_inode);
}
Index: linux-2.6/fs/fs-writeback.c
===================================================================
--- linux-2.6.orig/fs/fs-writeback.c
+++ linux-2.6/fs/fs-writeback.c
@@ -1166,6 +1166,7 @@ static void wait_sb_inodes(struct super_
WARN_ON(!rwsem_is_locked(&sb->s_umount));

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);

/*
* Data integrity sync. Must wait for all pages under writeback,
@@ -1183,6 +1184,7 @@ static void wait_sb_inodes(struct super_
if (mapping->nrpages == 0)
continue;
__iget(inode);
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
/*
* We hold a reference to 'inode' so it couldn't have
@@ -1200,7 +1202,9 @@ static void wait_sb_inodes(struct super_
cond_resched();

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
}
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
iput(old_inode);
}
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c
+++ linux-2.6/fs/inode.c
@@ -27,6 +27,15 @@
#include <linux/posix_acl.h>

/*
+ * Usage:
+ * sb_inode_list_lock protects:
+ * s_inodes, i_sb_list
+ *
+ * Ordering:
+ * inode_lock
+ * sb_inode_list_lock
+ */
+/*
* This is needed for the following functions:
* - inode_has_buffers
* - invalidate_inode_buffers
@@ -84,6 +93,7 @@ static struct hlist_head *inode_hashtabl
* the i_state of an inode while it is in use..
*/
DEFINE_SPINLOCK(inode_lock);
+DEFINE_SPINLOCK(sb_inode_list_lock);

/*
* iprune_sem provides exclusion between the kswapd or try_to_free_pages
@@ -344,7 +354,9 @@ static void dispose_list(struct list_hea

spin_lock(&inode_lock);
hlist_del_init(&inode->i_hash);
+ spin_lock(&sb_inode_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);

wake_up_inode(inode);
@@ -376,6 +388,7 @@ static int invalidate_list(struct list_h
* shrink_icache_memory() away.
*/
cond_resched_lock(&inode_lock);
+ cond_resched_lock(&sb_inode_list_lock);

next = next->next;
if (tmp == head)
@@ -413,9 +426,11 @@ int invalidate_inodes(struct super_block

down_write(&iprune_sem);
spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
inotify_unmount_inodes(&sb->s_inodes);
fsnotify_unmount_inodes(&sb->s_inodes);
busy = invalidate_list(&sb->s_inodes, &throw_away);
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);

dispose_list(&throw_away);
@@ -603,7 +618,9 @@ __inode_add_to_lists(struct super_block
{
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
+ spin_lock(&sb_inode_list_lock);
list_add(&inode->i_sb_list, &sb->s_inodes);
+ spin_unlock(&sb_inode_list_lock);
if (head)
hlist_add_head(&inode->i_hash, head);
}
@@ -1197,7 +1214,9 @@ void generic_delete_inode(struct inode *
const struct super_operations *op = inode->i_sb->s_op;

list_del_init(&inode->i_list);
+ spin_lock(&sb_inode_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&sb_inode_list_lock);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
inodes_stat.nr_inodes--;
@@ -1255,7 +1274,9 @@ int generic_detach_inode(struct inode *i
hlist_del_init(&inode->i_hash);
}
list_del_init(&inode->i_list);
+ spin_lock(&sb_inode_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&sb_inode_list_lock);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
inodes_stat.nr_inodes--;
Index: linux-2.6/fs/notify/inotify/inotify.c
===================================================================
--- linux-2.6.orig/fs/notify/inotify/inotify.c
+++ linux-2.6/fs/notify/inotify/inotify.c
@@ -429,6 +429,7 @@ void inotify_unmount_inodes(struct list_
* will be added since the umount has begun. Finally,
* iprune_mutex keeps shrink_icache_memory() away.
*/
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);

if (need_iput_tmp)
@@ -451,6 +452,7 @@ void inotify_unmount_inodes(struct list_
iput(inode);

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
}
}
EXPORT_SYMBOL_GPL(inotify_unmount_inodes);
Index: linux-2.6/fs/quota/dquot.c
===================================================================
--- linux-2.6.orig/fs/quota/dquot.c
+++ linux-2.6/fs/quota/dquot.c
@@ -884,6 +884,7 @@ static void add_dquot_ref(struct super_b
#endif

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
continue;
@@ -897,6 +898,7 @@ static void add_dquot_ref(struct super_b
continue;

__iget(inode);
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);

iput(old_inode);
@@ -908,7 +910,9 @@ static void add_dquot_ref(struct super_b
* keep the reference and iput it later. */
old_inode = inode;
spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
}
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
iput(old_inode);

@@ -988,6 +992,7 @@ static void remove_dquot_ref(struct supe
struct inode *inode;

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We have to scan also I_NEW inodes because they can already
@@ -998,6 +1003,7 @@ static void remove_dquot_ref(struct supe
if (!IS_NOQUOTA(inode))
remove_inode_dquot_ref(inode, type, tofree_head);
}
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);
}

Index: linux-2.6/include/linux/writeback.h
===================================================================
--- linux-2.6.orig/include/linux/writeback.h
+++ linux-2.6/include/linux/writeback.h
@@ -10,6 +10,7 @@
struct backing_dev_info;

extern spinlock_t inode_lock;
+extern spinlock_t sb_inode_list_lock;
extern struct list_head inode_in_use;
extern struct list_head inode_unused;

Index: linux-2.6/fs/notify/inode_mark.c
===================================================================
--- linux-2.6.orig/fs/notify/inode_mark.c
+++ linux-2.6/fs/notify/inode_mark.c
@@ -408,6 +408,7 @@ void fsnotify_unmount_inodes(struct list
* will be added since the umount has begun. Finally,
* iprune_mutex keeps shrink_icache_memory() away.
*/
+ spin_unlock(&sb_inode_list_lock);
spin_unlock(&inode_lock);

if (need_iput_tmp)
@@ -421,5 +422,6 @@ void fsnotify_unmount_inodes(struct list
iput(inode);

spin_lock(&inode_lock);
+ spin_lock(&sb_inode_list_lock);
}
}


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Prev: [patch 02/52] fs: fix superblock iteration race
Next: [patch 24/52] fs: dcache reduce d_parent locking