2007-09-23 11:15:13

by cheng renquan

Subject: [PATCH] vfs: use the predefined d_unhashed inline function instead

Signed-off-by: Denis Cheng <[email protected]>
---
fs/dcache.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 678d39d..62e1800 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1546,7 +1546,7 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target)
}

/* Move the dentry to the target hash queue, if on different bucket */
- if (dentry->d_flags & DCACHE_UNHASHED)
+ if (d_unhashed(dentry))
goto already_unhashed;

hlist_del_rcu(&dentry->d_hash);
--
1.5.3

2007-09-25 20:05:36

by cheng renquan

Subject: [PATCH] fs/dcache.c: revamped to use a more straightforward and efficient way to operate

Signed-off-by: Denis Cheng <[email protected]>
---
fs/dcache.c | 39 ++++++++++++++++++---------------------
1 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 678d39d..05ed44a 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1138,29 +1138,26 @@ struct dentry * d_alloc_anon(struct inode *inode)

spin_lock(&dcache_lock);
res = __d_find_alias(inode, 0);
- if (!res) {
- /* attach a disconnected dentry */
- res = tmp;
- tmp = NULL;
- spin_lock(&res->d_lock);
- res->d_sb = inode->i_sb;
- res->d_parent = res;
- res->d_inode = inode;
- res->d_flags |= DCACHE_DISCONNECTED;
- res->d_flags &= ~DCACHE_UNHASHED;
- list_add(&res->d_alias, &inode->i_dentry);
- hlist_add_head(&res->d_hash, &inode->i_sb->s_anon);
- spin_unlock(&res->d_lock);
-
- inode = NULL; /* don't drop reference */
- }
- spin_unlock(&dcache_lock);
-
- if (inode)
+ if (unlikely(res)) {
+ spin_unlock(&dcache_lock);
iput(inode);
- if (tmp)
dput(tmp);
- return res;
+ return res;
+ } else {
+ /* attach a disconnected dentry */
+ spin_lock(&tmp->d_lock);
+ tmp->d_sb = inode->i_sb;
+ tmp->d_parent = tmp;
+ tmp->d_inode = inode;
+ tmp->d_flags |= DCACHE_DISCONNECTED;
+ tmp->d_flags &= ~DCACHE_UNHASHED;
+ list_add(&tmp->d_alias, &inode->i_dentry);
+ hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
+ spin_unlock(&tmp->d_lock);
+
+ spin_unlock(&dcache_lock);
+ return tmp;
+ }
}


--
1.5.3.2

2007-10-01 17:25:30

by Jan Kara

Subject: Re: [PATCH] fs/dcache.c: revamped to use a more straightforward and efficient way to operate

Hello,

thanks for the patch. I have a few comments to it:
1) the patch should have a description in it, not only an email subject
2) usually, if an 'if' branch ends with return, as is the case in your
patch, we don't use 'else' for the other branch...

BTW: I'm not convinced your code would be faster (or slower) than the
original one but you're right it will be easier to read...

Honza

> Signed-off-by: Denis Cheng <[email protected]>
> ---
> fs/dcache.c | 39 ++++++++++++++++++---------------------
> 1 files changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/fs/dcache.c b/fs/dcache.c
> index 678d39d..05ed44a 100644
> --- a/fs/dcache.c
> +++ b/fs/dcache.c
> @@ -1138,29 +1138,26 @@ struct dentry * d_alloc_anon(struct inode *inode)
>
> spin_lock(&dcache_lock);
> res = __d_find_alias(inode, 0);
> - if (!res) {
> - /* attach a disconnected dentry */
> - res = tmp;
> - tmp = NULL;
> - spin_lock(&res->d_lock);
> - res->d_sb = inode->i_sb;
> - res->d_parent = res;
> - res->d_inode = inode;
> - res->d_flags |= DCACHE_DISCONNECTED;
> - res->d_flags &= ~DCACHE_UNHASHED;
> - list_add(&res->d_alias, &inode->i_dentry);
> - hlist_add_head(&res->d_hash, &inode->i_sb->s_anon);
> - spin_unlock(&res->d_lock);
> -
> - inode = NULL; /* don't drop reference */
> - }
> - spin_unlock(&dcache_lock);
> -
> - if (inode)
> + if (unlikely(res)) {
> + spin_unlock(&dcache_lock);
> iput(inode);
> - if (tmp)
> dput(tmp);
> - return res;
> + return res;
> + } else {
> + /* attach a disconnected dentry */
> + spin_lock(&tmp->d_lock);
> + tmp->d_sb = inode->i_sb;
> + tmp->d_parent = tmp;
> + tmp->d_inode = inode;
> + tmp->d_flags |= DCACHE_DISCONNECTED;
> + tmp->d_flags &= ~DCACHE_UNHASHED;
> + list_add(&tmp->d_alias, &inode->i_dentry);
> + hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
> + spin_unlock(&tmp->d_lock);
> +
> + spin_unlock(&dcache_lock);
> + return tmp;
> + }
> }
>
>
> --
> 1.5.3.2
>
> -
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--
Jan Kara <[email protected]>
SuSE CR Labs