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Diffstat (limited to 'include/linux/dcache.h')
-rw-r--r--include/linux/dcache.h51
1 files changed, 37 insertions, 14 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index d07cf2f1bb7d..4afb60365675 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -57,6 +57,7 @@ struct qstr {
};
#define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
+#define QSTR(n) (struct qstr)QSTR_INIT(n, strlen(n))
extern const struct qstr empty_name;
extern const struct qstr slash_name;
@@ -68,16 +69,24 @@ extern const struct qstr dotdot_name;
* large memory footprint increase).
*/
#ifdef CONFIG_64BIT
-# define DNAME_INLINE_LEN 40 /* 192 bytes */
+# define DNAME_INLINE_WORDS 5 /* 192 bytes */
#else
# ifdef CONFIG_SMP
-# define DNAME_INLINE_LEN 40 /* 128 bytes */
+# define DNAME_INLINE_WORDS 9 /* 128 bytes */
# else
-# define DNAME_INLINE_LEN 44 /* 128 bytes */
+# define DNAME_INLINE_WORDS 11 /* 128 bytes */
# endif
#endif
+#define DNAME_INLINE_LEN (DNAME_INLINE_WORDS*sizeof(unsigned long))
+
+union shortname_store {
+ unsigned char string[DNAME_INLINE_LEN];
+ unsigned long words[DNAME_INLINE_WORDS];
+};
+
#define d_lock d_lockref.lock
+#define d_iname d_shortname.string
struct dentry {
/* RCU lookup touched fields */
@@ -88,14 +97,19 @@ struct dentry {
struct qstr d_name;
struct inode *d_inode; /* Where the name belongs to - NULL is
* negative */
- unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
+ union shortname_store d_shortname;
+ /* --- cacheline 1 boundary (64 bytes) was 32 bytes ago --- */
/* Ref lookup also touches following */
- struct lockref d_lockref; /* per-dentry lock and refcount */
const struct dentry_operations *d_op;
struct super_block *d_sb; /* The root of the dentry tree */
unsigned long d_time; /* used by d_revalidate */
void *d_fsdata; /* fs-specific data */
+ /* --- cacheline 2 boundary (128 bytes) --- */
+ struct lockref d_lockref; /* per-dentry lock and refcount
+ * keep separate from RCU lookup area if
+ * possible!
+ */
union {
struct list_head d_lru; /* LRU list */
@@ -125,8 +139,14 @@ enum dentry_d_lock_class
DENTRY_D_LOCK_NESTED
};
+enum d_real_type {
+ D_REAL_DATA,
+ D_REAL_METADATA,
+};
+
struct dentry_operations {
- int (*d_revalidate)(struct dentry *, unsigned int);
+ int (*d_revalidate)(struct inode *, const struct qstr *,
+ struct dentry *, unsigned int);
int (*d_weak_revalidate)(struct dentry *, unsigned int);
int (*d_hash)(const struct dentry *, struct qstr *);
int (*d_compare)(const struct dentry *,
@@ -139,7 +159,9 @@ struct dentry_operations {
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
int (*d_manage)(const struct path *, bool);
- struct dentry *(*d_real)(struct dentry *, const struct inode *);
+ struct dentry *(*d_real)(struct dentry *, enum d_real_type type);
+ bool (*d_unalias_trylock)(const struct dentry *);
+ void (*d_unalias_unlock)(const struct dentry *);
} ____cacheline_aligned;
/*
@@ -273,6 +295,8 @@ static inline unsigned d_count(const struct dentry *dentry)
return dentry->d_lockref.count;
}
+ino_t d_parent_ino(struct dentry *dentry);
+
/*
* helper function for dentry_operations.d_dname() members
*/
@@ -547,24 +571,23 @@ static inline struct inode *d_backing_inode(const struct dentry *upper)
/**
* d_real - Return the real dentry
* @dentry: the dentry to query
- * @inode: inode to select the dentry from multiple layers (can be NULL)
+ * @type: the type of real dentry (data or metadata)
*
* If dentry is on a union/overlay, then return the underlying, real dentry.
* Otherwise return the dentry itself.
*
* See also: Documentation/filesystems/vfs.rst
*/
-static inline struct dentry *d_real(struct dentry *dentry,
- const struct inode *inode)
+static inline struct dentry *d_real(struct dentry *dentry, enum d_real_type type)
{
if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
- return dentry->d_op->d_real(dentry, inode);
+ return dentry->d_op->d_real(dentry, type);
else
return dentry;
}
/**
- * d_real_inode - Return the real inode
+ * d_real_inode - Return the real inode hosting the data
* @dentry: The dentry to query
*
* If dentry is on a union/overlay, then return the underlying, real inode.
@@ -573,12 +596,12 @@ static inline struct dentry *d_real(struct dentry *dentry,
static inline struct inode *d_real_inode(const struct dentry *dentry)
{
/* This usage of d_real() results in const dentry */
- return d_backing_inode(d_real((struct dentry *) dentry, NULL));
+ return d_inode(d_real((struct dentry *) dentry, D_REAL_DATA));
}
struct name_snapshot {
struct qstr name;
- unsigned char inline_name[DNAME_INLINE_LEN];
+ union shortname_store inline_name;
};
void take_dentry_name_snapshot(struct name_snapshot *, struct dentry *);
void release_dentry_name_snapshot(struct name_snapshot *);