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/isofs/inode.c b/fs/isofs/inode.c
index bfdeb82..7b0fbc6 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -28,14 +28,26 @@
static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
static int isofs_hash(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_dentry_cmpi(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);
+static int isofs_dentry_cmp(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);
#ifdef CONFIG_JOLIET
static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_dentry_cmpi_ms(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);
+static int isofs_dentry_cmp_ms(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);
#endif
static void isofs_put_super(struct super_block *sb)
@@ -206,49 +218,31 @@
}
/*
- * Case insensitive compare of two isofs names.
+ * Compare of two isofs names.
*/
-static int isofs_dentry_cmpi_common(struct dentry *dentry, struct qstr *a,
- struct qstr *b, int ms)
+static int isofs_dentry_cmp_common(
+ unsigned int len, const char *str,
+ const struct qstr *name, int ms, int ci)
{
int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
- alen = a->len;
- blen = b->len;
+ alen = name->len;
+ blen = len;
if (ms) {
- while (alen && a->name[alen-1] == '.')
+ while (alen && name->name[alen-1] == '.')
alen--;
- while (blen && b->name[blen-1] == '.')
+ while (blen && str[blen-1] == '.')
blen--;
}
if (alen == blen) {
- if (strnicmp(a->name, b->name, alen) == 0)
- return 0;
- }
- return 1;
-}
-
-/*
- * Case sensitive compare of two isofs names.
- */
-static int isofs_dentry_cmp_common(struct dentry *dentry, struct qstr *a,
- struct qstr *b, int ms)
-{
- int alen, blen;
-
- /* A filename cannot end in '.' or we treat it like it has none */
- alen = a->len;
- blen = b->len;
- if (ms) {
- while (alen && a->name[alen-1] == '.')
- alen--;
- while (blen && b->name[blen-1] == '.')
- blen--;
- }
- if (alen == blen) {
- if (strncmp(a->name, b->name, alen) == 0)
- return 0;
+ if (ci) {
+ if (strnicmp(name->name, str, alen) == 0)
+ return 0;
+ } else {
+ if (strncmp(name->name, str, alen) == 0)
+ return 0;
+ }
}
return 1;
}
@@ -266,15 +260,19 @@
}
static int
-isofs_dentry_cmp(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp(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)
{
- return isofs_dentry_cmp_common(dentry, a, b, 0);
+ return isofs_dentry_cmp_common(len, str, name, 0, 0);
}
static int
-isofs_dentry_cmpi(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi(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)
{
- return isofs_dentry_cmpi_common(dentry, a, b, 0);
+ return isofs_dentry_cmp_common(len, str, name, 0, 1);
}
#ifdef CONFIG_JOLIET
@@ -291,15 +289,19 @@
}
static int
-isofs_dentry_cmp_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp_ms(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)
{
- return isofs_dentry_cmp_common(dentry, a, b, 1);
+ return isofs_dentry_cmp_common(len, str, name, 1, 0);
}
static int
-isofs_dentry_cmpi_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi_ms(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)
{
- return isofs_dentry_cmpi_common(dentry, a, b, 1);
+ return isofs_dentry_cmp_common(len, str, name, 1, 1);
}
#endif