601 lines
18 KiB
C
601 lines
18 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_DCACHE_H
|
|
#define __LINUX_DCACHE_H
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/list.h>
|
|
#include <linux/math.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/rculist_bl.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/seqlock.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/lockref.h>
|
|
#include <linux/stringhash.h>
|
|
#include <linux/wait.h>
|
|
|
|
struct path;
|
|
struct file;
|
|
struct vfsmount;
|
|
|
|
/*
|
|
* linux/include/linux/dcache.h
|
|
*
|
|
* Dirent cache data structures
|
|
*
|
|
* (C) Copyright 1997 Thomas Schoebel-Theuer,
|
|
* with heavy changes by Linus Torvalds
|
|
*/
|
|
|
|
#define IS_ROOT(x) ((x) == (x)->d_parent)
|
|
|
|
/* 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
|
|
|
|
/*
|
|
* "quick string" -- eases parameter passing, but more importantly
|
|
* saves "metadata" about the string (ie length and the hash).
|
|
*
|
|
* hash comes first so it snuggles against d_parent in the
|
|
* dentry.
|
|
*/
|
|
struct qstr {
|
|
union {
|
|
struct {
|
|
HASH_LEN_DECLARE;
|
|
};
|
|
u64 hash_len;
|
|
};
|
|
const unsigned char *name;
|
|
};
|
|
|
|
#define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
|
|
|
|
extern const struct qstr empty_name;
|
|
extern const struct qstr slash_name;
|
|
extern const struct qstr dotdot_name;
|
|
|
|
/*
|
|
* Try to keep struct dentry aligned on 64 byte cachelines (this will
|
|
* give reasonable cacheline footprint with larger lines without the
|
|
* large memory footprint increase).
|
|
*/
|
|
#ifdef CONFIG_64BIT
|
|
# define DNAME_INLINE_LEN 40 /* 192 bytes */
|
|
#else
|
|
# ifdef CONFIG_SMP
|
|
# define DNAME_INLINE_LEN 40 /* 128 bytes */
|
|
# else
|
|
# define DNAME_INLINE_LEN 44 /* 128 bytes */
|
|
# endif
|
|
#endif
|
|
|
|
#define d_lock d_lockref.lock
|
|
|
|
struct dentry {
|
|
/* RCU lookup touched fields */
|
|
unsigned int d_flags; /* protected by d_lock */
|
|
seqcount_spinlock_t d_seq; /* per dentry seqlock */
|
|
struct hlist_bl_node d_hash; /* lookup hash list */
|
|
struct dentry *d_parent; /* parent directory */
|
|
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 */
|
|
|
|
/* 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 */
|
|
|
|
union {
|
|
struct list_head d_lru; /* LRU list */
|
|
wait_queue_head_t *d_wait; /* in-lookup ones only */
|
|
};
|
|
struct hlist_node d_sib; /* child of parent list */
|
|
struct hlist_head d_children; /* our children */
|
|
/*
|
|
* d_alias and d_rcu can share memory
|
|
*/
|
|
union {
|
|
struct hlist_node d_alias; /* inode alias list */
|
|
struct hlist_bl_node d_in_lookup_hash; /* only for in-lookup ones */
|
|
struct rcu_head d_rcu;
|
|
} d_u;
|
|
};
|
|
|
|
/*
|
|
* dentry->d_lock spinlock nesting subclasses:
|
|
*
|
|
* 0: normal
|
|
* 1: nested
|
|
*/
|
|
enum dentry_d_lock_class
|
|
{
|
|
DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
|
|
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_weak_revalidate)(struct dentry *, unsigned int);
|
|
int (*d_hash)(const struct dentry *, struct qstr *);
|
|
int (*d_compare)(const struct dentry *,
|
|
unsigned int, const char *, const struct qstr *);
|
|
int (*d_delete)(const struct dentry *);
|
|
int (*d_init)(struct dentry *);
|
|
void (*d_release)(struct dentry *);
|
|
void (*d_prune)(struct dentry *);
|
|
void (*d_iput)(struct dentry *, struct inode *);
|
|
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 *, enum d_real_type type);
|
|
} ____cacheline_aligned;
|
|
|
|
/*
|
|
* Locking rules for dentry_operations callbacks are to be found in
|
|
* Documentation/filesystems/locking.rst. Keep it updated!
|
|
*
|
|
* FUrther descriptions are found in Documentation/filesystems/vfs.rst.
|
|
* Keep it updated too!
|
|
*/
|
|
|
|
/* d_flags entries */
|
|
#define DCACHE_OP_HASH BIT(0)
|
|
#define DCACHE_OP_COMPARE BIT(1)
|
|
#define DCACHE_OP_REVALIDATE BIT(2)
|
|
#define DCACHE_OP_DELETE BIT(3)
|
|
#define DCACHE_OP_PRUNE BIT(4)
|
|
|
|
#define DCACHE_DISCONNECTED BIT(5)
|
|
/* 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
|
|
* endeavour to clear the bit either by discovering that it is connected,
|
|
* or by performing lookup operations. Any filesystem which supports
|
|
* nfsd_operations MUST have a lookup function which, if it finds a
|
|
* directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
|
|
* dentry into place and return that dentry rather than the passed one,
|
|
* typically using d_splice_alias. */
|
|
|
|
#define DCACHE_REFERENCED BIT(6) /* Recently used, don't discard. */
|
|
|
|
#define DCACHE_DONTCACHE BIT(7) /* Purge from memory on final dput() */
|
|
|
|
#define DCACHE_CANT_MOUNT BIT(8)
|
|
#define DCACHE_GENOCIDE BIT(9)
|
|
#define DCACHE_SHRINK_LIST BIT(10)
|
|
|
|
#define DCACHE_OP_WEAK_REVALIDATE BIT(11)
|
|
|
|
#define DCACHE_NFSFS_RENAMED BIT(12)
|
|
/* this dentry has been "silly renamed" and has to be deleted on the last
|
|
* dput() */
|
|
#define DCACHE_FSNOTIFY_PARENT_WATCHED BIT(14)
|
|
/* Parent inode is watched by some fsnotify listener */
|
|
|
|
#define DCACHE_DENTRY_KILLED BIT(15)
|
|
|
|
#define DCACHE_MOUNTED BIT(16) /* is a mountpoint */
|
|
#define DCACHE_NEED_AUTOMOUNT BIT(17) /* handle automount on this dir */
|
|
#define DCACHE_MANAGE_TRANSIT BIT(18) /* manage transit from this dirent */
|
|
#define DCACHE_MANAGED_DENTRY \
|
|
(DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
|
|
|
|
#define DCACHE_LRU_LIST BIT(19)
|
|
|
|
#define DCACHE_ENTRY_TYPE (7 << 20) /* bits 20..22 are for storing type: */
|
|
#define DCACHE_MISS_TYPE (0 << 20) /* Negative dentry */
|
|
#define DCACHE_WHITEOUT_TYPE (1 << 20) /* Whiteout dentry (stop pathwalk) */
|
|
#define DCACHE_DIRECTORY_TYPE (2 << 20) /* Normal directory */
|
|
#define DCACHE_AUTODIR_TYPE (3 << 20) /* Lookupless directory (presumed automount) */
|
|
#define DCACHE_REGULAR_TYPE (4 << 20) /* Regular file type */
|
|
#define DCACHE_SPECIAL_TYPE (5 << 20) /* Other file type */
|
|
#define DCACHE_SYMLINK_TYPE (6 << 20) /* Symlink */
|
|
|
|
#define DCACHE_NOKEY_NAME BIT(25) /* Encrypted name encoded without key */
|
|
#define DCACHE_OP_REAL BIT(26)
|
|
|
|
#define DCACHE_PAR_LOOKUP BIT(28) /* being looked up (with parent locked shared) */
|
|
#define DCACHE_DENTRY_CURSOR BIT(29)
|
|
#define DCACHE_NORCU BIT(30) /* No RCU delay for freeing */
|
|
|
|
extern seqlock_t rename_lock;
|
|
|
|
/*
|
|
* These are the low-level FS interfaces to the dcache..
|
|
*/
|
|
extern void d_instantiate(struct dentry *, struct inode *);
|
|
extern void d_instantiate_new(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 void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
|
|
|
|
/* allocate/de-allocate */
|
|
extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
|
|
extern struct dentry * d_alloc_anon(struct super_block *);
|
|
extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
|
|
wait_queue_head_t *);
|
|
extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
|
|
extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
|
|
extern bool d_same_name(const struct dentry *dentry, const struct dentry *parent,
|
|
const struct qstr *name);
|
|
extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
|
|
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 d_invalidate(struct dentry *);
|
|
|
|
/* only used at mount-time */
|
|
extern struct dentry * d_make_root(struct inode *);
|
|
|
|
extern void d_mark_tmpfile(struct file *, struct inode *);
|
|
extern void d_tmpfile(struct file *, struct inode *);
|
|
|
|
extern struct dentry *d_find_alias(struct inode *);
|
|
extern void d_prune_aliases(struct inode *);
|
|
|
|
extern struct dentry *d_find_alias_rcu(struct inode *);
|
|
|
|
/* test whether we have any submounts in a subdir tree */
|
|
extern int path_has_submounts(const struct path *);
|
|
|
|
/*
|
|
* This adds the entry to the hash queues.
|
|
*/
|
|
extern void d_rehash(struct dentry *);
|
|
|
|
extern void d_add(struct dentry *, 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 *);
|
|
|
|
extern struct dentry *d_lookup(const struct dentry *, const struct qstr *);
|
|
extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
|
|
|
|
static inline unsigned d_count(const struct dentry *dentry)
|
|
{
|
|
return dentry->d_lockref.count;
|
|
}
|
|
|
|
/*
|
|
* helper function for dentry_operations.d_dname() members
|
|
*/
|
|
extern __printf(3, 4)
|
|
char *dynamic_dname(char *, int, const char *, ...);
|
|
|
|
extern char *__d_path(const struct path *, const struct path *, char *, int);
|
|
extern char *d_absolute_path(const struct path *, char *, int);
|
|
extern char *d_path(const struct path *, char *, int);
|
|
extern char *dentry_path_raw(const struct dentry *, char *, int);
|
|
extern char *dentry_path(const struct dentry *, char *, int);
|
|
|
|
/* Allocation counts.. */
|
|
|
|
/**
|
|
* dget_dlock - get a reference to a dentry
|
|
* @dentry: dentry to get a reference to
|
|
*
|
|
* Given a live dentry, increment the reference count and return the dentry.
|
|
* Caller must hold @dentry->d_lock. Making sure that dentry is alive is
|
|
* caller's resonsibility. There are many conditions sufficient to guarantee
|
|
* that; e.g. anything with non-negative refcount is alive, so's anything
|
|
* hashed, anything positive, anyone's parent, etc.
|
|
*/
|
|
static inline struct dentry *dget_dlock(struct dentry *dentry)
|
|
{
|
|
dentry->d_lockref.count++;
|
|
return dentry;
|
|
}
|
|
|
|
|
|
/**
|
|
* dget - get a reference to a dentry
|
|
* @dentry: dentry to get a reference to
|
|
*
|
|
* Given a dentry or %NULL pointer increment the reference count
|
|
* if appropriate and return the dentry. A dentry will not be
|
|
* destroyed when it has references. Conversely, a dentry with
|
|
* no references can disappear for any number of reasons, starting
|
|
* with memory pressure. In other words, that primitive is
|
|
* used to clone an existing reference; using it on something with
|
|
* zero refcount is a bug.
|
|
*
|
|
* NOTE: it will spin if @dentry->d_lock is held. From the deadlock
|
|
* avoidance point of view it is equivalent to spin_lock()/increment
|
|
* refcount/spin_unlock(), so calling it under @dentry->d_lock is
|
|
* always a bug; so's calling it under ->d_lock on any of its descendents.
|
|
*
|
|
*/
|
|
static inline struct dentry *dget(struct dentry *dentry)
|
|
{
|
|
if (dentry)
|
|
lockref_get(&dentry->d_lockref);
|
|
return dentry;
|
|
}
|
|
|
|
extern struct dentry *dget_parent(struct dentry *dentry);
|
|
|
|
/**
|
|
* d_unhashed - is dentry hashed
|
|
* @dentry: entry to check
|
|
*
|
|
* Returns true if the dentry passed is not currently hashed.
|
|
*/
|
|
static inline int d_unhashed(const struct dentry *dentry)
|
|
{
|
|
return hlist_bl_unhashed(&dentry->d_hash);
|
|
}
|
|
|
|
static inline int d_unlinked(const struct dentry *dentry)
|
|
{
|
|
return d_unhashed(dentry) && !IS_ROOT(dentry);
|
|
}
|
|
|
|
static inline int cant_mount(const struct dentry *dentry)
|
|
{
|
|
return (dentry->d_flags & DCACHE_CANT_MOUNT);
|
|
}
|
|
|
|
static inline void dont_mount(struct dentry *dentry)
|
|
{
|
|
spin_lock(&dentry->d_lock);
|
|
dentry->d_flags |= DCACHE_CANT_MOUNT;
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
|
|
extern void __d_lookup_unhash_wake(struct dentry *dentry);
|
|
|
|
static inline int d_in_lookup(const struct dentry *dentry)
|
|
{
|
|
return dentry->d_flags & DCACHE_PAR_LOOKUP;
|
|
}
|
|
|
|
static inline void d_lookup_done(struct dentry *dentry)
|
|
{
|
|
if (unlikely(d_in_lookup(dentry)))
|
|
__d_lookup_unhash_wake(dentry);
|
|
}
|
|
|
|
extern void dput(struct dentry *);
|
|
|
|
static inline bool d_managed(const struct dentry *dentry)
|
|
{
|
|
return dentry->d_flags & DCACHE_MANAGED_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_flags_negative(unsigned flags)
|
|
{
|
|
return (flags & DCACHE_ENTRY_TYPE) == DCACHE_MISS_TYPE;
|
|
}
|
|
|
|
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(const struct dentry *dentry)
|
|
{
|
|
return d_really_is_positive(dentry) && !d_unhashed(dentry);
|
|
}
|
|
|
|
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 READ_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 READ_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_real - Return the real dentry
|
|
* @dentry: the dentry to query
|
|
* @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, enum d_real_type type)
|
|
{
|
|
if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
|
|
return dentry->d_op->d_real(dentry, type);
|
|
else
|
|
return dentry;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
* Otherwise return d_inode().
|
|
*/
|
|
static inline struct inode *d_real_inode(const struct dentry *dentry)
|
|
{
|
|
/* This usage of d_real() results in const dentry */
|
|
return d_inode(d_real((struct dentry *) dentry, D_REAL_DATA));
|
|
}
|
|
|
|
struct name_snapshot {
|
|
struct qstr name;
|
|
unsigned char inline_name[DNAME_INLINE_LEN];
|
|
};
|
|
void take_dentry_name_snapshot(struct name_snapshot *, struct dentry *);
|
|
void release_dentry_name_snapshot(struct name_snapshot *);
|
|
|
|
static inline struct dentry *d_first_child(const struct dentry *dentry)
|
|
{
|
|
return hlist_entry_safe(dentry->d_children.first, struct dentry, d_sib);
|
|
}
|
|
|
|
static inline struct dentry *d_next_sibling(const struct dentry *dentry)
|
|
{
|
|
return hlist_entry_safe(dentry->d_sib.next, struct dentry, d_sib);
|
|
}
|
|
|
|
#endif /* __LINUX_DCACHE_H */
|