From 4cb640248041dab1c718a6140d758dad5a84b8ec Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 3 Jul 2022 22:20:20 -0400 Subject: lookup_fast(): don't bother with inode Note that validation of ->d_seq after ->d_inode fetch is gone, along with fetching of ->d_inode itself. Signed-off-by: Al Viro --- fs/namei.c | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index d631d797ea09..3e30cec54ced 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1621,8 +1621,7 @@ static struct dentry *__lookup_hash(const struct qstr *name, return dentry; } -static struct dentry *lookup_fast(struct nameidata *nd, - struct inode **inode) +static struct dentry *lookup_fast(struct nameidata *nd) { struct dentry *dentry, *parent = nd->path.dentry; int status = 1; @@ -1640,22 +1639,11 @@ static struct dentry *lookup_fast(struct nameidata *nd, return NULL; } - /* - * This sequence count validates that the inode matches - * the dentry name information from lookup. - */ - *inode = d_backing_inode(dentry); - if (read_seqcount_retry(&dentry->d_seq, nd->next_seq)) - return ERR_PTR(-ECHILD); - /* * This sequence count validates that the parent had no * changes while we did the lookup of the dentry above. - * - * The memory barrier in read_seqcount_begin of child is - * enough, we can use __read_seqcount_retry here. */ - if (__read_seqcount_retry(&parent->d_seq, nd->seq)) + if (read_seqcount_retry(&parent->d_seq, nd->seq)) return ERR_PTR(-ECHILD); status = d_revalidate(dentry, nd->flags); @@ -1997,7 +1985,6 @@ static const char *handle_dots(struct nameidata *nd, int type) static const char *walk_component(struct nameidata *nd, int flags) { struct dentry *dentry; - struct inode *inode; /* * "." and ".." are special - ".." especially so because it has * to be able to know about the current root directory and @@ -2008,7 +1995,7 @@ static const char *walk_component(struct nameidata *nd, int flags) put_link(nd); return handle_dots(nd, nd->last_type); } - dentry = lookup_fast(nd, &inode); + dentry = lookup_fast(nd); if (IS_ERR(dentry)) return ERR_CAST(dentry); if (unlikely(!dentry)) { @@ -3396,7 +3383,6 @@ static const char *open_last_lookups(struct nameidata *nd, struct dentry *dir = nd->path.dentry; int open_flag = op->open_flag; bool got_write = false; - struct inode *inode; struct dentry *dentry; const char *res; @@ -3412,7 +3398,7 @@ static const char *open_last_lookups(struct nameidata *nd, if (nd->last.name[nd->last.len]) nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; /* we _can_ be in RCU mode here */ - dentry = lookup_fast(nd, &inode); + dentry = lookup_fast(nd); if (IS_ERR(dentry)) return ERR_CAST(dentry); if (likely(dentry)) -- cgit v1.2.3