[PATCH] fs/inode: No need to take ->i_lock right after alloc_inode()

From: Richard Weinberger
Date: Sat Dec 14 2013 - 15:56:15 EST


In all three cases, new_inode_pseudo(), iget_locked() and iget5_locked(),
we own the new inode exclusively at this point and therefore taking
->i_lock to protect ->i_state/->i_hash against concurrent access is superfluous.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
fs/inode.c | 6 ------
1 file changed, 6 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 4bcdad3..5f2a735 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -869,9 +869,7 @@ struct inode *new_inode_pseudo(struct super_block *sb)
struct inode *inode = alloc_inode(sb);

if (inode) {
- spin_lock(&inode->i_lock);
inode->i_state = 0;
- spin_unlock(&inode->i_lock);
INIT_LIST_HEAD(&inode->i_sb_list);
}
return inode;
@@ -1025,10 +1023,8 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
if (set(inode, data))
goto set_failed;

- spin_lock(&inode->i_lock);
inode->i_state = I_NEW;
hlist_add_head(&inode->i_hash, head);
- spin_unlock(&inode->i_lock);
inode_sb_list_add(inode);
spin_unlock(&inode_hash_lock);

@@ -1092,10 +1088,8 @@ struct inode *iget_locked(struct super_block *sb, unsigned long ino)
old = find_inode_fast(sb, head, ino);
if (!old) {
inode->i_ino = ino;
- spin_lock(&inode->i_lock);
inode->i_state = I_NEW;
hlist_add_head(&inode->i_hash, head);
- spin_unlock(&inode->i_lock);
inode_sb_list_add(inode);
spin_unlock(&inode_hash_lock);

--
1.8.4.2

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