ext3/4 with synchronous writes gets wedged by Postfix

OK, that's probably the easiest way to do that, as much as I don't like it...
Since iget() et.al. will not accept I_FREEING (will wait to go away
and restart), and since we'd better have serialization between new/free
on fs data structures anyway, we can afford simply skipping I_FREEING
et.al. in insert_inode_locked().

We do that from new_inode, so it won't race with free_inode in any interesting
ways and it won't race with iget (of any origin; nfsd or in case of fs
corruption a lookup) since both still will wait for I_LOCK.

Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Tested-by: David Watson <dbwatson@ukfsn.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2009-05-13 19:13:40 +01:00 committed by Al Viro
parent 460bcf57b1
commit 72a43d63cb

View file

@ -1053,13 +1053,22 @@ int insert_inode_locked(struct inode *inode)
struct super_block *sb = inode->i_sb;
ino_t ino = inode->i_ino;
struct hlist_head *head = inode_hashtable + hash(sb, ino);
struct inode *old;
inode->i_state |= I_LOCK|I_NEW;
while (1) {
struct hlist_node *node;
struct inode *old = NULL;
spin_lock(&inode_lock);
old = find_inode_fast(sb, head, ino);
if (likely(!old)) {
hlist_for_each_entry(old, node, head, i_hash) {
if (old->i_ino != ino)
continue;
if (old->i_sb != sb)
continue;
if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))
continue;
break;
}
if (likely(!node)) {
hlist_add_head(&inode->i_hash, head);
spin_unlock(&inode_lock);
return 0;
@ -1081,14 +1090,24 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
{
struct super_block *sb = inode->i_sb;
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
struct inode *old;
inode->i_state |= I_LOCK|I_NEW;
while (1) {
struct hlist_node *node;
struct inode *old = NULL;
spin_lock(&inode_lock);
old = find_inode(sb, head, test, data);
if (likely(!old)) {
hlist_for_each_entry(old, node, head, i_hash) {
if (old->i_sb != sb)
continue;
if (!test(old, data))
continue;
if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))
continue;
break;
}
if (likely(!node)) {
hlist_add_head(&inode->i_hash, head);
spin_unlock(&inode_lock);
return 0;