#include <linux/seqlock.h>
#include <linux/cache.h>
#include <linux/rcupdate.h>
+#include <linux/lockref.h>
-struct nameidata;
struct path;
struct vfsmount;
/* The hash is always the low bits of hash_len */
#ifdef __LITTLE_ENDIAN
#define HASH_LEN_DECLARE u32 hash; u32 len;
+ #define bytemask_from_count(cnt) (~(~0ul << (cnt)*8))
#else
#define HASH_LEN_DECLARE u32 len; u32 hash;
+ #define bytemask_from_count(cnt) (~(~0ul >> (cnt)*8))
#endif
/*
#define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
#define hashlen_hash(hashlen) ((u32) (hashlen))
#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
+#define hashlen_create(hash,len) (((u64)(len)<<32)|(u32)(hash))
struct dentry_stat_t {
- int nr_dentry;
- int nr_unused;
- int age_limit; /* age in seconds */
- int want_pages; /* pages requested by system */
- int dummy[2];
+ long nr_dentry;
+ long nr_unused;
+ long age_limit; /* age in seconds */
+ long want_pages; /* pages requested by system */
+ long dummy[2];
};
extern struct dentry_stat_t dentry_stat;
# endif
#endif
+#define d_lock d_lockref.lock
+
struct dentry {
/* RCU lookup touched fields */
unsigned int d_flags; /* protected by d_lock */
unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
/* Ref lookup also touches following */
- unsigned int d_count; /* protected by d_lock */
- spinlock_t d_lock; /* per dentry lock */
+ 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 */
struct list_head d_lru; /* LRU list */
+ struct list_head d_child; /* child of parent list */
+ struct list_head d_subdirs; /* our children */
/*
- * d_child and d_rcu can share memory
+ * d_alias and d_rcu can share memory
*/
union {
- struct list_head d_child; /* child of parent list */
+ struct hlist_node d_alias; /* inode alias list */
struct rcu_head d_rcu;
} d_u;
- struct list_head d_subdirs; /* our children */
- struct hlist_node d_alias; /* inode alias list */
};
/*
struct dentry_operations {
int (*d_revalidate)(struct dentry *, unsigned int);
int (*d_weak_revalidate)(struct dentry *, unsigned int);
- int (*d_hash)(const struct dentry *, const struct inode *,
- struct qstr *);
- int (*d_compare)(const struct dentry *, const struct inode *,
- const struct dentry *, const struct inode *,
+ int (*d_hash)(const struct dentry *, struct qstr *);
+ int (*d_compare)(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
int (*d_delete)(const struct dentry *);
void (*d_release)(struct dentry *);
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
int (*d_manage)(struct dentry *, bool);
+ struct inode *(*d_select_inode)(struct dentry *, unsigned);
+ void (*d_canonical_path)(const struct dentry *, struct path *);
+ struct dentry *(*d_real)(struct dentry *, struct inode *);
} ____cacheline_aligned;
/*
*/
/* d_flags entries */
-#define DCACHE_OP_HASH 0x0001
-#define DCACHE_OP_COMPARE 0x0002
-#define DCACHE_OP_REVALIDATE 0x0004
-#define DCACHE_OP_DELETE 0x0008
-#define DCACHE_OP_PRUNE 0x0010
+#define DCACHE_OP_HASH 0x00000001
+#define DCACHE_OP_COMPARE 0x00000002
+#define DCACHE_OP_REVALIDATE 0x00000004
+#define DCACHE_OP_DELETE 0x00000008
+#define DCACHE_OP_PRUNE 0x00000010
-#define DCACHE_DISCONNECTED 0x0020
+#define DCACHE_DISCONNECTED 0x00000020
/* This dentry is possibly not currently connected to the dcache tree, in
* which case its parent will either be itself, or will have this flag as
* well. nfsd will not use a dentry with this bit set, but will first
* dentry into place and return that dentry rather than the passed one,
* typically using d_splice_alias. */
-#define DCACHE_REFERENCED 0x0040 /* Recently used, don't discard. */
-#define DCACHE_RCUACCESS 0x0080 /* Entry has ever been RCU-visible */
+#define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */
+#define DCACHE_RCUACCESS 0x00000080 /* Entry has ever been RCU-visible */
-#define DCACHE_CANT_MOUNT 0x0100
-#define DCACHE_GENOCIDE 0x0200
-#define DCACHE_SHRINK_LIST 0x0400
+#define DCACHE_CANT_MOUNT 0x00000100
+#define DCACHE_GENOCIDE 0x00000200
+#define DCACHE_SHRINK_LIST 0x00000400
-#define DCACHE_OP_WEAK_REVALIDATE 0x0800
+#define DCACHE_OP_WEAK_REVALIDATE 0x00000800
-#define DCACHE_NFSFS_RENAMED 0x1000
+#define DCACHE_NFSFS_RENAMED 0x00001000
/* this dentry has been "silly renamed" and has to be deleted on the last
* dput() */
-#define DCACHE_COOKIE 0x2000 /* For use by dcookie subsystem */
-#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000
+#define DCACHE_COOKIE 0x00002000 /* For use by dcookie subsystem */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x00004000
/* Parent inode is watched by some fsnotify listener */
-#define DCACHE_MOUNTED 0x10000 /* is a mountpoint */
-#define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */
-#define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */
+#define DCACHE_DENTRY_KILLED 0x00008000
+
+#define DCACHE_MOUNTED 0x00010000 /* is a mountpoint */
+#define DCACHE_NEED_AUTOMOUNT 0x00020000 /* handle automount on this dir */
+#define DCACHE_MANAGE_TRANSIT 0x00040000 /* manage transit from this dirent */
#define DCACHE_MANAGED_DENTRY \
(DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
-#define DCACHE_DENTRY_KILLED 0x100000
+#define DCACHE_LRU_LIST 0x00080000
-extern seqlock_t rename_lock;
+#define DCACHE_ENTRY_TYPE 0x00700000
+#define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry (maybe fallthru to nowhere) */
+#define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */
+#define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */
+#define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */
+#define DCACHE_REGULAR_TYPE 0x00400000 /* Regular file type (or fallthru to such) */
+#define DCACHE_SPECIAL_TYPE 0x00500000 /* Other file type (or fallthru to such) */
+#define DCACHE_SYMLINK_TYPE 0x00600000 /* Symlink (or fallthru to such) */
-static inline int dname_external(struct dentry *dentry)
-{
- return dentry->d_name.name != dentry->d_iname;
-}
+#define DCACHE_MAY_FREE 0x00800000
+#define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
+#define DCACHE_OP_SELECT_INODE 0x02000000 /* Unioned entry: dcache op selects inode */
+#define DCACHE_OP_REAL 0x08000000
+
+extern seqlock_t rename_lock;
/*
* These are the low-level FS interfaces to the dcache..
*/
extern void d_instantiate(struct dentry *, struct inode *);
extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
-extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
+extern int d_instantiate_no_diralias(struct dentry *, struct inode *);
extern void __d_drop(struct dentry *dentry);
extern void d_drop(struct dentry *dentry);
extern void d_delete(struct dentry *);
extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
extern struct dentry *d_find_any_alias(struct inode *inode);
extern struct dentry * d_obtain_alias(struct inode *);
+extern struct dentry * d_obtain_root(struct inode *);
extern void shrink_dcache_sb(struct super_block *);
extern void shrink_dcache_parent(struct dentry *);
extern void shrink_dcache_for_umount(struct super_block *);
-extern int d_invalidate(struct dentry *);
+extern void d_invalidate(struct dentry *);
/* only used at mount-time */
extern struct dentry * d_make_root(struct inode *);
/* <clickety>-<click> the ramfs-type tree */
extern void d_genocide(struct dentry *);
+extern void d_tmpfile(struct dentry *, struct inode *);
+
extern struct dentry *d_find_alias(struct inode *);
extern void d_prune_aliases(struct inode *);
/* used for rename() and baskets */
extern void d_move(struct dentry *, struct dentry *);
+extern void d_exchange(struct dentry *, struct dentry *);
extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
/* appendix may either be NULL or be used for transname suffixes */
extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
- const struct qstr *name,
- unsigned *seq, struct inode *inode);
+ const struct qstr *name, unsigned *seq);
-/**
- * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok
- * @dentry: dentry to take a ref on
- * @seq: seqcount to verify against
- * Returns: 0 on failure, else 1.
- *
- * __d_rcu_to_refcount operates on a dentry,seq pair that was returned
- * by __d_lookup_rcu, to get a reference on an rcu-walk dentry.
- */
-static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
+static inline unsigned d_count(const struct dentry *dentry)
{
- int ret = 0;
-
- assert_spin_locked(&dentry->d_lock);
- if (!read_seqcount_retry(&dentry->d_seq, seq)) {
- ret = 1;
- dentry->d_count++;
- }
-
- return ret;
+ return dentry->d_lockref.count;
}
-/* validate "insecure" dentry pointer */
-extern int d_validate(struct dentry *, struct dentry *);
-
/*
* helper function for dentry_operations.d_dname() members
*/
-extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
+extern __printf(4, 5)
+char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
+extern char *simple_dname(struct dentry *, char *, int);
extern char *__d_path(const struct path *, const struct path *, char *, int);
extern char *d_absolute_path(const struct path *, char *, int);
static inline struct dentry *dget_dlock(struct dentry *dentry)
{
if (dentry)
- dentry->d_count++;
+ dentry->d_lockref.count++;
return dentry;
}
static inline struct dentry *dget(struct dentry *dentry)
{
- if (dentry) {
- spin_lock(&dentry->d_lock);
- dget_dlock(dentry);
- spin_unlock(&dentry->d_lock);
- }
+ if (dentry)
+ lockref_get(&dentry->d_lockref);
return dentry;
}
* Returns true if the dentry passed is not currently hashed.
*/
-static inline int d_unhashed(struct dentry *dentry)
+static inline int d_unhashed(const struct dentry *dentry)
{
return hlist_bl_unhashed(&dentry->d_hash);
}
-static inline int d_unlinked(struct dentry *dentry)
+static inline int d_unlinked(const struct dentry *dentry)
{
return d_unhashed(dentry) && !IS_ROOT(dentry);
}
-static inline int cant_mount(struct dentry *dentry)
+static inline int cant_mount(const struct dentry *dentry)
{
return (dentry->d_flags & DCACHE_CANT_MOUNT);
}
extern void dput(struct dentry *);
-static inline bool d_managed(struct dentry *dentry)
+static inline bool d_managed(const struct dentry *dentry)
{
return dentry->d_flags & DCACHE_MANAGED_DENTRY;
}
-static inline bool d_mountpoint(struct dentry *dentry)
+static inline bool d_mountpoint(const struct dentry *dentry)
{
return dentry->d_flags & DCACHE_MOUNTED;
}
+/*
+ * Directory cache entry type accessor functions.
+ */
+static inline unsigned __d_entry_type(const struct dentry *dentry)
+{
+ return dentry->d_flags & DCACHE_ENTRY_TYPE;
+}
+
+static inline bool d_is_miss(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_MISS_TYPE;
+}
+
+static inline bool d_is_whiteout(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_WHITEOUT_TYPE;
+}
+
+static inline bool d_can_lookup(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE;
+}
+
+static inline bool d_is_autodir(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_AUTODIR_TYPE;
+}
+
+static inline bool d_is_dir(const struct dentry *dentry)
+{
+ return d_can_lookup(dentry) || d_is_autodir(dentry);
+}
+
+static inline bool d_is_symlink(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
+}
+
+static inline bool d_is_reg(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_REGULAR_TYPE;
+}
+
+static inline bool d_is_special(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_SPECIAL_TYPE;
+}
+
+static inline bool d_is_file(const struct dentry *dentry)
+{
+ return d_is_reg(dentry) || d_is_special(dentry);
+}
+
+static inline bool d_is_negative(const struct dentry *dentry)
+{
+ // TODO: check d_is_whiteout(dentry) also.
+ return d_is_miss(dentry);
+}
+
+static inline bool d_is_positive(const struct dentry *dentry)
+{
+ return !d_is_negative(dentry);
+}
+
+/**
+ * d_really_is_negative - Determine if a dentry is really negative (ignoring fallthroughs)
+ * @dentry: The dentry in question
+ *
+ * Returns true if the dentry represents either an absent name or a name that
+ * doesn't map to an inode (ie. ->d_inode is NULL). The dentry could represent
+ * a true miss, a whiteout that isn't represented by a 0,0 chardev or a
+ * fallthrough marker in an opaque directory.
+ *
+ * Note! (1) This should be used *only* by a filesystem to examine its own
+ * dentries. It should not be used to look at some other filesystem's
+ * dentries. (2) It should also be used in combination with d_inode() to get
+ * the inode. (3) The dentry may have something attached to ->d_lower and the
+ * type field of the flags may be set to something other than miss or whiteout.
+ */
+static inline bool d_really_is_negative(const struct dentry *dentry)
+{
+ return dentry->d_inode == NULL;
+}
+
+/**
+ * d_really_is_positive - Determine if a dentry is really positive (ignoring fallthroughs)
+ * @dentry: The dentry in question
+ *
+ * Returns true if the dentry represents a name that maps to an inode
+ * (ie. ->d_inode is not NULL). The dentry might still represent a whiteout if
+ * that is represented on medium as a 0,0 chardev.
+ *
+ * Note! (1) This should be used *only* by a filesystem to examine its own
+ * dentries. It should not be used to look at some other filesystem's
+ * dentries. (2) It should also be used in combination with d_inode() to get
+ * the inode.
+ */
+static inline bool d_really_is_positive(const struct dentry *dentry)
+{
+ return dentry->d_inode != NULL;
+}
+
+static inline int simple_positive(struct dentry *dentry)
+{
+ return d_really_is_positive(dentry) && !d_unhashed(dentry);
+}
+
+extern void d_set_fallthru(struct dentry *dentry);
+
+static inline bool d_is_fallthru(const struct dentry *dentry)
+{
+ return dentry->d_flags & DCACHE_FALLTHRU;
+}
+
+
extern int sysctl_vfs_cache_pressure;
+static inline unsigned long vfs_pressure_ratio(unsigned long val)
+{
+ return mult_frac(val, sysctl_vfs_cache_pressure, 100);
+}
+
+/**
+ * d_inode - Get the actual inode of this dentry
+ * @dentry: The dentry to query
+ *
+ * This is the helper normal filesystems should use to get at their own inodes
+ * in their own dentries and ignore the layering superimposed upon them.
+ */
+static inline struct inode *d_inode(const struct dentry *dentry)
+{
+ return dentry->d_inode;
+}
+
+/**
+ * d_inode_rcu - Get the actual inode of this dentry with ACCESS_ONCE()
+ * @dentry: The dentry to query
+ *
+ * This is the helper normal filesystems should use to get at their own inodes
+ * in their own dentries and ignore the layering superimposed upon them.
+ */
+static inline struct inode *d_inode_rcu(const struct dentry *dentry)
+{
+ return ACCESS_ONCE(dentry->d_inode);
+}
+
+/**
+ * d_backing_inode - Get upper or lower inode we should be using
+ * @upper: The upper layer
+ *
+ * This is the helper that should be used to get at the inode that will be used
+ * if this dentry were to be opened as a file. The inode may be on the upper
+ * dentry or it may be on a lower dentry pinned by the upper.
+ *
+ * Normal filesystems should not use this to access their own inodes.
+ */
+static inline struct inode *d_backing_inode(const struct dentry *upper)
+{
+ struct inode *inode = upper->d_inode;
+
+ return inode;
+}
+
+/**
+ * d_backing_dentry - Get upper or lower dentry we should be using
+ * @upper: The upper layer
+ *
+ * This is the helper that should be used to get the dentry of the inode that
+ * will be used if this dentry were opened as a file. It may be the upper
+ * dentry or it may be a lower dentry pinned by the upper.
+ *
+ * Normal filesystems should not use this to access their own dentries.
+ */
+static inline struct dentry *d_backing_dentry(struct dentry *upper)
+{
+ return upper;
+}
+
+static inline struct dentry *d_real(struct dentry *dentry)
+{
+ if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
+ return dentry->d_op->d_real(dentry, NULL);
+ else
+ return dentry;
+}
+
+static inline struct inode *vfs_select_inode(struct dentry *dentry,
+ unsigned open_flags)
+{
+ struct inode *inode = d_inode(dentry);
+
+ if (inode && unlikely(dentry->d_flags & DCACHE_OP_SELECT_INODE))
+ inode = dentry->d_op->d_select_inode(dentry, open_flags);
+
+ return inode;
+}
+
+
#endif /* __LINUX_DCACHE_H */
projects / firefly-linux-kernel-4.4.55.git / blobdiff