[PATCH 3/4] configfs: fold configfs_attach_attr into configfs_lookup

From: Christoph Hellwig
Date: Wed Aug 25 2021 - 02:53:05 EST


This makes it more clear what gets added to the dcache and prepares
for an additional locking fix.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/configfs/dir.c | 73 ++++++++++++++++-------------------------------
1 file changed, 24 insertions(+), 49 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 5d58569f0eea..fc20bd8a6337 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -45,7 +45,7 @@ static void configfs_d_iput(struct dentry * dentry,
/*
* Set sd->s_dentry to null only when this dentry is the one
* that is going to be killed. Otherwise configfs_d_iput may
- * run just after configfs_attach_attr and set sd->s_dentry to
+ * run just after configfs_lookup and set sd->s_dentry to
* NULL even it's still in use.
*/
if (sd->s_dentry == dentry)
@@ -417,44 +417,13 @@ static void configfs_remove_dir(struct config_item * item)
dput(dentry);
}

-
-/* attaches attribute's configfs_dirent to the dentry corresponding to the
- * attribute file
- */
-static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
-{
- struct configfs_attribute * attr = sd->s_element;
- struct inode *inode;
-
- spin_lock(&configfs_dirent_lock);
- dentry->d_fsdata = configfs_get(sd);
- sd->s_dentry = dentry;
- spin_unlock(&configfs_dirent_lock);
-
- inode = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG);
- if (IS_ERR(inode)) {
- configfs_put(sd);
- return PTR_ERR(inode);
- }
- if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) {
- inode->i_size = 0;
- inode->i_fop = &configfs_bin_file_operations;
- } else {
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &configfs_file_operations;
- }
- d_add(dentry, inode);
- return 0;
-}
-
static struct dentry * configfs_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags)
{
struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
struct configfs_dirent * sd;
- int found = 0;
- int err;
+ struct inode *inode = NULL;

if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
@@ -471,28 +440,34 @@ static struct dentry * configfs_lookup(struct inode *dir,
return ERR_PTR(-ENOENT);

list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_type & CONFIGFS_NOT_PINNED) {
- const unsigned char * name = configfs_get_name(sd);
+ if ((sd->s_type & CONFIGFS_NOT_PINNED) &&
+ !strcmp(configfs_get_name(sd), dentry->d_name.name)) {
+ struct configfs_attribute *attr = sd->s_element;
+ umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG;

- if (strcmp(name, dentry->d_name.name))
- continue;
+ spin_lock(&configfs_dirent_lock);
+ dentry->d_fsdata = configfs_get(sd);
+ sd->s_dentry = dentry;
+ spin_unlock(&configfs_dirent_lock);

- found = 1;
- err = configfs_attach_attr(sd, dentry);
+ inode = configfs_create(dentry, mode);
+ if (IS_ERR(inode)) {
+ configfs_put(sd);
+ return ERR_CAST(inode);
+ }
+ if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) {
+ inode->i_size = 0;
+ inode->i_fop = &configfs_bin_file_operations;
+ } else {
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &configfs_file_operations;
+ }
break;
}
}

- if (!found) {
- /*
- * If it doesn't exist and it isn't a NOT_PINNED item,
- * it must be negative.
- */
- d_add(dentry, NULL);
- return NULL;
- }
-
- return ERR_PTR(err);
+ d_add(dentry, inode);
+ return NULL;
}

/*
--
2.30.2