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fs: factor inode disposal

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We have a couple of places that dispose of inodes. factor the
disposal into evict() to isolate this code and make it simpler to
peel away the inode_lock from the code.

While doing this, change the logic flow in iput_final() to separate
the different cases that need to be handled to make the transitions
the inode goes through more obvious.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Dave Chinner 2011-03-22 22:23:37 +11:00 committed by Al Viro
parent 250df6ed27
commit b2b2af8e61
1 changed files with 42 additions and 64 deletions
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106
fs/inode.c
View file

@ -422,17 +422,6 @@ void __insert_inode_hash(struct inode *inode, unsigned long hashval)
}
EXPORT_SYMBOL(__insert_inode_hash);
/**
* __remove_inode_hash - remove an inode from the hash
* @inode: inode to unhash
*
* Remove an inode from the superblock.
*/
static void __remove_inode_hash(struct inode *inode)
{
hlist_del_init(&inode->i_hash);
}
/**
* remove_inode_hash - remove an inode from the hash
* @inode: inode to unhash
@ -462,10 +451,31 @@ void end_writeback(struct inode *inode)
}
EXPORT_SYMBOL(end_writeback);
/*
* Free the inode passed in, removing it from the lists it is still connected
* to. We remove any pages still attached to the inode and wait for any IO that
* is still in progress before finally destroying the inode.
*
* An inode must already be marked I_FREEING so that we avoid the inode being
* moved back onto lists if we race with other code that manipulates the lists
* (e.g. writeback_single_inode). The caller is responsible for setting this.
*
* An inode must already be removed from the LRU list before being evicted from
* the cache. This should occur atomically with setting the I_FREEING state
* flag, so no inodes here should ever be on the LRU when being evicted.
*/
static void evict(struct inode *inode)
{
const struct super_operations *op = inode->i_sb->s_op;
BUG_ON(!(inode->i_state & I_FREEING));
BUG_ON(!list_empty(&inode->i_lru));
spin_lock(&inode_lock);
list_del_init(&inode->i_wb_list);
__inode_sb_list_del(inode);
spin_unlock(&inode_lock);
if (op->evict_inode) {
op->evict_inode(inode);
} else {
@ -477,6 +487,15 @@ static void evict(struct inode *inode)
bd_forget(inode);
if (S_ISCHR(inode->i_mode) && inode->i_cdev)
cd_forget(inode);
remove_inode_hash(inode);
spin_lock(&inode->i_lock);
wake_up_bit(&inode->i_state, __I_NEW);
BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
spin_unlock(&inode->i_lock);
destroy_inode(inode);
}
/*
@ -495,16 +514,6 @@ static void dispose_list(struct list_head *head)
list_del_init(&inode->i_lru);
evict(inode);
spin_lock(&inode_lock);
__remove_inode_hash(inode);
__inode_sb_list_del(inode);
spin_unlock(&inode_lock);
spin_lock(&inode->i_lock);
wake_up_bit(&inode->i_state, __I_NEW);
spin_unlock(&inode->i_lock);
destroy_inode(inode);
}
}
@ -537,13 +546,7 @@ void evict_inodes(struct super_block *sb)
if (!(inode->i_state & (I_DIRTY | I_SYNC)))
inodes_stat.nr_unused--;
spin_unlock(&inode->i_lock);
/*
* Move the inode off the IO lists and LRU once I_FREEING is
* set so that it won't get moved back on there if it is dirty.
*/
list_move(&inode->i_lru, &dispose);
list_del_init(&inode->i_wb_list);
}
spin_unlock(&inode_lock);
@ -596,13 +599,7 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
if (!(inode->i_state & (I_DIRTY | I_SYNC)))
inodes_stat.nr_unused--;
spin_unlock(&inode->i_lock);
/*
* Move the inode off the IO lists and LRU once I_FREEING is
* set so that it won't get moved back on there if it is dirty.
*/
list_move(&inode->i_lru, &dispose);
list_del_init(&inode->i_wb_list);
}
spin_unlock(&inode_lock);
@ -699,12 +696,7 @@ static void prune_icache(int nr_to_scan)
inode->i_state |= I_FREEING;
spin_unlock(&inode->i_lock);
/*
* Move the inode off the IO lists and LRU once I_FREEING is
* set so that it won't get moved back on there if it is dirty.
*/
list_move(&inode->i_lru, &freeable);
list_del_init(&inode->i_wb_list);
inodes_stat.nr_unused--;
}
if (current_is_kswapd())
@ -1434,16 +1426,16 @@ static void iput_final(struct inode *inode)
else
drop = generic_drop_inode(inode);
if (!drop && (sb->s_flags & MS_ACTIVE)) {
inode->i_state |= I_REFERENCED;
if (!(inode->i_state & (I_DIRTY|I_SYNC)))
inode_lru_list_add(inode);
spin_unlock(&inode->i_lock);
spin_unlock(&inode_lock);
return;
}
if (!drop) {
if (sb->s_flags & MS_ACTIVE) {
inode->i_state |= I_REFERENCED;
if (!(inode->i_state & (I_DIRTY|I_SYNC))) {
inode_lru_list_add(inode);
}
spin_unlock(&inode->i_lock);
spin_unlock(&inode_lock);
return;
}
inode->i_state |= I_WILL_FREE;
spin_unlock(&inode->i_lock);
spin_unlock(&inode_lock);
@ -1452,28 +1444,14 @@ static void iput_final(struct inode *inode)
spin_lock(&inode->i_lock);
WARN_ON(inode->i_state & I_NEW);
inode->i_state &= ~I_WILL_FREE;
__remove_inode_hash(inode);
}
inode->i_state |= I_FREEING;
spin_unlock(&inode->i_lock);
/*
* Move the inode off the IO lists and LRU once I_FREEING is
* set so that it won't get moved back on there if it is dirty.
*/
inode_lru_list_del(inode);
list_del_init(&inode->i_wb_list);
__inode_sb_list_del(inode);
spin_unlock(&inode_lock);
evict(inode);
remove_inode_hash(inode);
spin_lock(&inode->i_lock);
wake_up_bit(&inode->i_state, __I_NEW);
BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
spin_unlock(&inode->i_lock);
destroy_inode(inode);
spin_unlock(&inode_lock);
evict(inode);
}
/**