romfs_lookup: switch to d_splice_alias()

... and hash negative lookups

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2018-04-30 20:08:17 -04:00
parent c1481700f4
commit 8130c15176

View File

@ -213,7 +213,7 @@ static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
unsigned long offset, maxoff;
struct inode *inode;
struct inode *inode = NULL;
struct romfs_inode ri;
const char *name; /* got from dentry */
int len, ret;
@ -233,7 +233,7 @@ static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
for (;;) {
if (!offset || offset >= maxoff)
goto out0;
break;
ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri));
if (ret < 0)
@ -244,37 +244,19 @@ static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
len);
if (ret < 0)
goto error;
if (ret == 1)
if (ret == 1) {
/* Hard link handling */
if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
inode = romfs_iget(dir->i_sb, offset);
break;
}
/* next entry */
offset = be32_to_cpu(ri.next) & ROMFH_MASK;
}
/* Hard link handling */
if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
inode = romfs_iget(dir->i_sb, offset);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto error;
}
goto outi;
/*
* it's a bit funky, _lookup needs to return an error code
* (negative) or a NULL, both as a dentry. ENOENT should not
* be returned, instead we need to create a negative dentry by
* d_add(dentry, NULL); and return 0 as no error.
* (Although as I see, it only matters on writable file
* systems).
*/
out0:
inode = NULL;
outi:
d_add(dentry, inode);
ret = 0;
return d_splice_alias(inode, dentry);
error:
return ERR_PTR(ret);
}