fs: change d_compare for rcu-walk
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index e80ea4e..3bcc68a 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -75,7 +75,9 @@
*/
static int ncp_lookup_validate(struct dentry *, struct nameidata *);
static int ncp_hash_dentry(struct dentry *, struct qstr *);
-static int ncp_compare_dentry (struct dentry *, struct qstr *, struct qstr *);
+static int ncp_compare_dentry(const struct dentry *, const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
static int ncp_delete_dentry(const struct dentry *);
static const struct dentry_operations ncp_dentry_operations =
@@ -113,10 +115,10 @@
#define ncp_preserve_case(i) (ncp_namespace(i) != NW_NS_DOS)
-static inline int ncp_case_sensitive(struct dentry *dentry)
+static inline int ncp_case_sensitive(const struct inode *i)
{
#ifdef CONFIG_NCPFS_NFS_NS
- return ncp_namespace(dentry->d_inode) == NW_NS_NFS;
+ return ncp_namespace(i) == NW_NS_NFS;
#else
return 0;
#endif /* CONFIG_NCPFS_NFS_NS */
@@ -129,12 +131,13 @@
static int
ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
{
- if (!ncp_case_sensitive(dentry)) {
+ if (!ncp_case_sensitive(dentry->d_inode)) {
+ struct super_block *sb = dentry->d_sb;
struct nls_table *t;
unsigned long hash;
int i;
- t = NCP_IO_TABLE(dentry);
+ t = NCP_IO_TABLE(sb);
hash = init_name_hash();
for (i=0; i<this->len ; i++)
hash = partial_name_hash(ncp_tolower(t, this->name[i]),
@@ -145,15 +148,17 @@
}
static int
-ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+ncp_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- if (a->len != b->len)
+ if (len != name->len)
return 1;
- if (ncp_case_sensitive(dentry))
- return strncmp(a->name, b->name, a->len);
+ if (ncp_case_sensitive(pinode))
+ return strncmp(str, name->name, len);
- return ncp_strnicmp(NCP_IO_TABLE(dentry), a->name, b->name, a->len);
+ return ncp_strnicmp(NCP_IO_TABLE(pinode->i_sb), str, name->name, len);
}
/*