Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef __LINUX_DCACHE_H |
| 2 | #define __LINUX_DCACHE_H |
| 3 | |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 4 | #include <linux/atomic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | #include <linux/list.h> |
Franck Bui-Huu | 8252474 | 2008-05-12 21:21:05 +0200 | [diff] [blame] | 6 | #include <linux/rculist.h> |
Nick Piggin | ceb5bdc | 2011-01-07 17:50:05 +1100 | [diff] [blame] | 7 | #include <linux/rculist_bl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/spinlock.h> |
Nick Piggin | 31e6b01 | 2011-01-07 17:49:52 +1100 | [diff] [blame] | 9 | #include <linux/seqlock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/cache.h> |
| 11 | #include <linux/rcupdate.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
| 13 | struct nameidata; |
Jan Blunck | cf28b48 | 2008-02-14 19:38:44 -0800 | [diff] [blame] | 14 | struct path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | struct vfsmount; |
| 16 | |
| 17 | /* |
| 18 | * linux/include/linux/dcache.h |
| 19 | * |
| 20 | * Dirent cache data structures |
| 21 | * |
| 22 | * (C) Copyright 1997 Thomas Schoebel-Theuer, |
| 23 | * with heavy changes by Linus Torvalds |
| 24 | */ |
| 25 | |
| 26 | #define IS_ROOT(x) ((x) == (x)->d_parent) |
| 27 | |
Linus Torvalds | 26fe575 | 2012-05-10 13:14:12 -0700 | [diff] [blame] | 28 | /* The hash is always the low bits of hash_len */ |
| 29 | #ifdef __LITTLE_ENDIAN |
| 30 | #define HASH_LEN_DECLARE u32 hash; u32 len; |
| 31 | #else |
| 32 | #define HASH_LEN_DECLARE u32 len; u32 hash; |
| 33 | #endif |
| 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | /* |
| 36 | * "quick string" -- eases parameter passing, but more importantly |
| 37 | * saves "metadata" about the string (ie length and the hash). |
| 38 | * |
| 39 | * hash comes first so it snuggles against d_parent in the |
| 40 | * dentry. |
| 41 | */ |
| 42 | struct qstr { |
Linus Torvalds | 26fe575 | 2012-05-10 13:14:12 -0700 | [diff] [blame] | 43 | union { |
| 44 | struct { |
| 45 | HASH_LEN_DECLARE; |
| 46 | }; |
| 47 | u64 hash_len; |
| 48 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | const unsigned char *name; |
| 50 | }; |
| 51 | |
Linus Torvalds | 26fe575 | 2012-05-10 13:14:12 -0700 | [diff] [blame] | 52 | #define QSTR_INIT(n,l) { { { .len = l } }, .name = n } |
| 53 | #define hashlen_hash(hashlen) ((u32) (hashlen)) |
| 54 | #define hashlen_len(hashlen) ((u32)((hashlen) >> 32)) |
| 55 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | struct dentry_stat_t { |
| 57 | int nr_dentry; |
| 58 | int nr_unused; |
| 59 | int age_limit; /* age in seconds */ |
| 60 | int want_pages; /* pages requested by system */ |
| 61 | int dummy[2]; |
| 62 | }; |
| 63 | extern struct dentry_stat_t dentry_stat; |
| 64 | |
| 65 | /* Name hashing routines. Initial hash value */ |
| 66 | /* Hash courtesy of the R5 hash in reiserfs modulo sign bits */ |
| 67 | #define init_name_hash() 0 |
| 68 | |
| 69 | /* partial hash update function. Assume roughly 4 bits per character */ |
| 70 | static inline unsigned long |
| 71 | partial_name_hash(unsigned long c, unsigned long prevhash) |
| 72 | { |
| 73 | return (prevhash + (c << 4) + (c >> 4)) * 11; |
| 74 | } |
| 75 | |
| 76 | /* |
| 77 | * Finally: cut down the number of bits to a int value (and try to avoid |
| 78 | * losing bits) |
| 79 | */ |
| 80 | static inline unsigned long end_name_hash(unsigned long hash) |
| 81 | { |
| 82 | return (unsigned int) hash; |
| 83 | } |
| 84 | |
| 85 | /* Compute the hash for a name string. */ |
Linus Torvalds | 0145acc | 2012-03-02 14:32:59 -0800 | [diff] [blame] | 86 | extern unsigned int full_name_hash(const unsigned char *, unsigned int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | |
Nick Piggin | c2452f3 | 2008-12-01 09:33:43 +0100 | [diff] [blame] | 88 | /* |
| 89 | * Try to keep struct dentry aligned on 64 byte cachelines (this will |
| 90 | * give reasonable cacheline footprint with larger lines without the |
| 91 | * large memory footprint increase). |
| 92 | */ |
| 93 | #ifdef CONFIG_64BIT |
Nick Piggin | 44a7d7a | 2011-01-07 17:49:56 +1100 | [diff] [blame] | 94 | # define DNAME_INLINE_LEN 32 /* 192 bytes */ |
Nick Piggin | c2452f3 | 2008-12-01 09:33:43 +0100 | [diff] [blame] | 95 | #else |
Nick Piggin | 44a7d7a | 2011-01-07 17:49:56 +1100 | [diff] [blame] | 96 | # ifdef CONFIG_SMP |
| 97 | # define DNAME_INLINE_LEN 36 /* 128 bytes */ |
| 98 | # else |
| 99 | # define DNAME_INLINE_LEN 40 /* 128 bytes */ |
| 100 | # endif |
Nick Piggin | c2452f3 | 2008-12-01 09:33:43 +0100 | [diff] [blame] | 101 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
| 103 | struct dentry { |
Nick Piggin | 44a7d7a | 2011-01-07 17:49:56 +1100 | [diff] [blame] | 104 | /* RCU lookup touched fields */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | unsigned int d_flags; /* protected by d_lock */ |
Nick Piggin | 31e6b01 | 2011-01-07 17:49:52 +1100 | [diff] [blame] | 106 | seqcount_t d_seq; /* per dentry seqlock */ |
Nick Piggin | ceb5bdc | 2011-01-07 17:50:05 +1100 | [diff] [blame] | 107 | struct hlist_bl_node d_hash; /* lookup hash list */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | struct dentry *d_parent; /* parent directory */ |
| 109 | struct qstr d_name; |
Nick Piggin | 44a7d7a | 2011-01-07 17:49:56 +1100 | [diff] [blame] | 110 | struct inode *d_inode; /* Where the name belongs to - NULL is |
| 111 | * negative */ |
| 112 | unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */ |
| 113 | |
| 114 | /* Ref lookup also touches following */ |
| 115 | unsigned int d_count; /* protected by d_lock */ |
| 116 | spinlock_t d_lock; /* per dentry lock */ |
| 117 | const struct dentry_operations *d_op; |
| 118 | struct super_block *d_sb; /* The root of the dentry tree */ |
| 119 | unsigned long d_time; /* used by d_revalidate */ |
| 120 | void *d_fsdata; /* fs-specific data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | |
| 122 | struct list_head d_lru; /* LRU list */ |
Eric Dumazet | 5160ee6 | 2006-01-08 01:03:32 -0800 | [diff] [blame] | 123 | /* |
| 124 | * d_child and d_rcu can share memory |
| 125 | */ |
| 126 | union { |
| 127 | struct list_head d_child; /* child of parent list */ |
| 128 | struct rcu_head d_rcu; |
| 129 | } d_u; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | struct list_head d_subdirs; /* our children */ |
Al Viro | b3d9b7a | 2012-06-09 13:51:19 -0400 | [diff] [blame] | 131 | struct hlist_node d_alias; /* inode alias list */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | }; |
| 133 | |
Ingo Molnar | a90b9c0 | 2006-07-03 00:25:04 -0700 | [diff] [blame] | 134 | /* |
| 135 | * dentry->d_lock spinlock nesting subclasses: |
| 136 | * |
| 137 | * 0: normal |
| 138 | * 1: nested |
| 139 | */ |
| 140 | enum dentry_d_lock_class |
| 141 | { |
| 142 | DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */ |
| 143 | DENTRY_D_LOCK_NESTED |
| 144 | }; |
| 145 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | struct dentry_operations { |
Al Viro | 0b728e1 | 2012-06-10 16:03:43 -0400 | [diff] [blame] | 147 | int (*d_revalidate)(struct dentry *, unsigned int); |
Jeff Layton | ecf3d1f | 2013-02-20 11:19:05 -0500 | [diff] [blame] | 148 | int (*d_weak_revalidate)(struct dentry *, unsigned int); |
Nick Piggin | b1e6a01 | 2011-01-07 17:49:28 +1100 | [diff] [blame] | 149 | int (*d_hash)(const struct dentry *, const struct inode *, |
| 150 | struct qstr *); |
Nick Piggin | 621e155 | 2011-01-07 17:49:27 +1100 | [diff] [blame] | 151 | int (*d_compare)(const struct dentry *, const struct inode *, |
| 152 | const struct dentry *, const struct inode *, |
| 153 | unsigned int, const char *, const struct qstr *); |
Nick Piggin | fe15ce4 | 2011-01-07 17:49:23 +1100 | [diff] [blame] | 154 | int (*d_delete)(const struct dentry *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | void (*d_release)(struct dentry *); |
Sage Weil | f0023bc | 2011-10-28 10:02:42 -0700 | [diff] [blame] | 156 | void (*d_prune)(struct dentry *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | void (*d_iput)(struct dentry *, struct inode *); |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 158 | char *(*d_dname)(struct dentry *, char *, int); |
David Howells | 9875cf8 | 2011-01-14 18:45:21 +0000 | [diff] [blame] | 159 | struct vfsmount *(*d_automount)(struct path *); |
Al Viro | 1aed3e4 | 2011-03-18 09:09:02 -0400 | [diff] [blame] | 160 | int (*d_manage)(struct dentry *, bool); |
Nick Piggin | 44a7d7a | 2011-01-07 17:49:56 +1100 | [diff] [blame] | 161 | } ____cacheline_aligned; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
Nick Piggin | 5eef7fa | 2011-01-07 17:49:22 +1100 | [diff] [blame] | 163 | /* |
| 164 | * Locking rules for dentry_operations callbacks are to be found in |
| 165 | * Documentation/filesystems/Locking. Keep it updated! |
| 166 | * |
Nick Piggin | 621e155 | 2011-01-07 17:49:27 +1100 | [diff] [blame] | 167 | * FUrther descriptions are found in Documentation/filesystems/vfs.txt. |
| 168 | * Keep it updated too! |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | */ |
| 170 | |
| 171 | /* d_flags entries */ |
Linus Torvalds | 830c0f0 | 2011-08-06 22:41:50 -0700 | [diff] [blame] | 172 | #define DCACHE_OP_HASH 0x0001 |
| 173 | #define DCACHE_OP_COMPARE 0x0002 |
| 174 | #define DCACHE_OP_REVALIDATE 0x0004 |
| 175 | #define DCACHE_OP_DELETE 0x0008 |
Sage Weil | f0023bc | 2011-10-28 10:02:42 -0700 | [diff] [blame] | 176 | #define DCACHE_OP_PRUNE 0x0010 |
Nick Piggin | 5f57cbc | 2011-01-07 17:49:54 +1100 | [diff] [blame] | 177 | |
Sage Weil | f0023bc | 2011-10-28 10:02:42 -0700 | [diff] [blame] | 178 | #define DCACHE_DISCONNECTED 0x0020 |
Nick Piggin | 5f57cbc | 2011-01-07 17:49:54 +1100 | [diff] [blame] | 179 | /* This dentry is possibly not currently connected to the dcache tree, in |
| 180 | * which case its parent will either be itself, or will have this flag as |
| 181 | * well. nfsd will not use a dentry with this bit set, but will first |
| 182 | * endeavour to clear the bit either by discovering that it is connected, |
| 183 | * or by performing lookup operations. Any filesystem which supports |
| 184 | * nfsd_operations MUST have a lookup function which, if it finds a |
| 185 | * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that |
| 186 | * dentry into place and return that dentry rather than the passed one, |
| 187 | * typically using d_splice_alias. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
Sage Weil | f0023bc | 2011-10-28 10:02:42 -0700 | [diff] [blame] | 189 | #define DCACHE_REFERENCED 0x0040 /* Recently used, don't discard. */ |
| 190 | #define DCACHE_RCUACCESS 0x0080 /* Entry has ever been RCU-visible */ |
Eric Paris | c28f7e5 | 2009-05-21 17:01:29 -0400 | [diff] [blame] | 191 | |
Al Viro | d83c49f | 2010-04-30 17:17:09 -0400 | [diff] [blame] | 192 | #define DCACHE_CANT_MOUNT 0x0100 |
Nick Piggin | 949854d | 2011-01-07 17:49:37 +1100 | [diff] [blame] | 193 | #define DCACHE_GENOCIDE 0x0200 |
Miklos Szeredi | eaf5f90 | 2012-01-10 18:22:25 +0100 | [diff] [blame] | 194 | #define DCACHE_SHRINK_LIST 0x0400 |
Nick Piggin | 5f57cbc | 2011-01-07 17:49:54 +1100 | [diff] [blame] | 195 | |
Jeff Layton | ecf3d1f | 2013-02-20 11:19:05 -0500 | [diff] [blame] | 196 | #define DCACHE_OP_WEAK_REVALIDATE 0x0800 |
| 197 | |
Linus Torvalds | 830c0f0 | 2011-08-06 22:41:50 -0700 | [diff] [blame] | 198 | #define DCACHE_NFSFS_RENAMED 0x1000 |
| 199 | /* this dentry has been "silly renamed" and has to be deleted on the last |
| 200 | * dput() */ |
| 201 | #define DCACHE_COOKIE 0x2000 /* For use by dcookie subsystem */ |
| 202 | #define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000 |
| 203 | /* Parent inode is watched by some fsnotify listener */ |
Nick Piggin | fb045ad | 2011-01-07 17:49:55 +1100 | [diff] [blame] | 204 | |
David Howells | 9875cf8 | 2011-01-14 18:45:21 +0000 | [diff] [blame] | 205 | #define DCACHE_MOUNTED 0x10000 /* is a mountpoint */ |
| 206 | #define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */ |
David Howells | cc53ce5 | 2011-01-14 18:45:26 +0000 | [diff] [blame] | 207 | #define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */ |
David Howells | 9875cf8 | 2011-01-14 18:45:21 +0000 | [diff] [blame] | 208 | #define DCACHE_MANAGED_DENTRY \ |
David Howells | cc53ce5 | 2011-01-14 18:45:26 +0000 | [diff] [blame] | 209 | (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT) |
David Howells | 9875cf8 | 2011-01-14 18:45:21 +0000 | [diff] [blame] | 210 | |
Miklos Szeredi | b161dfa6 | 2012-09-17 22:31:38 +0200 | [diff] [blame] | 211 | #define DCACHE_DENTRY_KILLED 0x100000 |
| 212 | |
Al Viro | 74c3cbe | 2007-07-22 08:04:18 -0400 | [diff] [blame] | 213 | extern seqlock_t rename_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | static inline int dname_external(struct dentry *dentry) |
| 216 | { |
| 217 | return dentry->d_name.name != dentry->d_iname; |
| 218 | } |
| 219 | |
| 220 | /* |
| 221 | * These are the low-level FS interfaces to the dcache.. |
| 222 | */ |
| 223 | extern void d_instantiate(struct dentry *, struct inode *); |
| 224 | extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *); |
David Howells | 770bfad | 2006-08-22 20:06:07 -0400 | [diff] [blame] | 225 | extern struct dentry * d_materialise_unique(struct dentry *, struct inode *); |
Nick Piggin | 789680d | 2011-01-07 17:49:30 +1100 | [diff] [blame] | 226 | extern void __d_drop(struct dentry *dentry); |
| 227 | extern void d_drop(struct dentry *dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | extern void d_delete(struct dentry *); |
Nick Piggin | fb045ad | 2011-01-07 17:49:55 +1100 | [diff] [blame] | 229 | extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | |
| 231 | /* allocate/de-allocate */ |
| 232 | extern struct dentry * d_alloc(struct dentry *, const struct qstr *); |
Nick Piggin | 4b93688 | 2011-01-07 17:50:07 +1100 | [diff] [blame] | 233 | extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | extern struct dentry * d_splice_alias(struct inode *, struct dentry *); |
Christoph Hellwig | e45b590 | 2008-08-07 23:49:07 +0200 | [diff] [blame] | 235 | extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *); |
Sage Weil | 46f72b3 | 2012-01-10 09:04:37 -0800 | [diff] [blame] | 236 | extern struct dentry *d_find_any_alias(struct inode *inode); |
Christoph Hellwig | 4ea3ada | 2008-08-11 15:48:57 +0200 | [diff] [blame] | 237 | extern struct dentry * d_obtain_alias(struct inode *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | extern void shrink_dcache_sb(struct super_block *); |
| 239 | extern void shrink_dcache_parent(struct dentry *); |
David Howells | c636ebd | 2006-10-11 01:22:19 -0700 | [diff] [blame] | 240 | extern void shrink_dcache_for_umount(struct super_block *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | extern int d_invalidate(struct dentry *); |
| 242 | |
| 243 | /* only used at mount-time */ |
Al Viro | adc0e91 | 2012-01-08 16:49:21 -0500 | [diff] [blame] | 244 | extern struct dentry * d_make_root(struct inode *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | |
| 246 | /* <clickety>-<click> the ramfs-type tree */ |
| 247 | extern void d_genocide(struct dentry *); |
| 248 | |
| 249 | extern struct dentry *d_find_alias(struct inode *); |
| 250 | extern void d_prune_aliases(struct inode *); |
| 251 | |
| 252 | /* test whether we have any submounts in a subdir tree */ |
| 253 | extern int have_submounts(struct dentry *); |
| 254 | |
| 255 | /* |
| 256 | * This adds the entry to the hash queues. |
| 257 | */ |
| 258 | extern void d_rehash(struct dentry *); |
| 259 | |
| 260 | /** |
| 261 | * d_add - add dentry to hash queues |
| 262 | * @entry: dentry to add |
| 263 | * @inode: The inode to attach to this dentry |
| 264 | * |
| 265 | * This adds the entry to the hash queues and initializes @inode. |
| 266 | * The entry was actually filled in earlier during d_alloc(). |
| 267 | */ |
| 268 | |
| 269 | static inline void d_add(struct dentry *entry, struct inode *inode) |
| 270 | { |
| 271 | d_instantiate(entry, inode); |
| 272 | d_rehash(entry); |
| 273 | } |
| 274 | |
| 275 | /** |
| 276 | * d_add_unique - add dentry to hash queues without aliasing |
| 277 | * @entry: dentry to add |
| 278 | * @inode: The inode to attach to this dentry |
| 279 | * |
| 280 | * This adds the entry to the hash queues and initializes @inode. |
| 281 | * The entry was actually filled in earlier during d_alloc(). |
| 282 | */ |
| 283 | static inline struct dentry *d_add_unique(struct dentry *entry, struct inode *inode) |
| 284 | { |
| 285 | struct dentry *res; |
| 286 | |
| 287 | res = d_instantiate_unique(entry, inode); |
| 288 | d_rehash(res != NULL ? res : entry); |
| 289 | return res; |
| 290 | } |
| 291 | |
Nick Piggin | fb2d5b8 | 2011-01-07 17:49:26 +1100 | [diff] [blame] | 292 | extern void dentry_update_name_case(struct dentry *, struct qstr *); |
| 293 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | /* used for rename() and baskets */ |
| 295 | extern void d_move(struct dentry *, struct dentry *); |
OGAWA Hirofumi | e2761a1 | 2008-10-16 07:50:28 +0900 | [diff] [blame] | 296 | extern struct dentry *d_ancestor(struct dentry *, struct dentry *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | |
| 298 | /* appendix may either be NULL or be used for transname suffixes */ |
Al Viro | da2d845 | 2013-01-24 18:29:34 -0500 | [diff] [blame] | 299 | extern struct dentry *d_lookup(const struct dentry *, const struct qstr *); |
Nick Piggin | 31e6b01 | 2011-01-07 17:49:52 +1100 | [diff] [blame] | 300 | extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *); |
Al Viro | a713ca2 | 2013-01-24 18:27:00 -0500 | [diff] [blame] | 301 | extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *); |
Linus Torvalds | 8966be9 | 2012-03-02 14:23:30 -0800 | [diff] [blame] | 302 | extern struct dentry *__d_lookup_rcu(const struct dentry *parent, |
| 303 | const struct qstr *name, |
Linus Torvalds | 12f8ad4 | 2012-05-04 14:59:14 -0700 | [diff] [blame] | 304 | unsigned *seq, struct inode *inode); |
Nick Piggin | 31e6b01 | 2011-01-07 17:49:52 +1100 | [diff] [blame] | 305 | |
| 306 | /** |
| 307 | * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok |
| 308 | * @dentry: dentry to take a ref on |
| 309 | * @seq: seqcount to verify against |
Randy Dunlap | 2a8c0c68 | 2011-01-08 19:37:20 -0800 | [diff] [blame] | 310 | * Returns: 0 on failure, else 1. |
Nick Piggin | 31e6b01 | 2011-01-07 17:49:52 +1100 | [diff] [blame] | 311 | * |
| 312 | * __d_rcu_to_refcount operates on a dentry,seq pair that was returned |
| 313 | * by __d_lookup_rcu, to get a reference on an rcu-walk dentry. |
| 314 | */ |
| 315 | static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq) |
| 316 | { |
| 317 | int ret = 0; |
| 318 | |
| 319 | assert_spin_locked(&dentry->d_lock); |
| 320 | if (!read_seqcount_retry(&dentry->d_seq, seq)) { |
| 321 | ret = 1; |
| 322 | dentry->d_count++; |
| 323 | } |
| 324 | |
| 325 | return ret; |
| 326 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
| 328 | /* validate "insecure" dentry pointer */ |
| 329 | extern int d_validate(struct dentry *, struct dentry *); |
| 330 | |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 331 | /* |
| 332 | * helper function for dentry_operations.d_dname() members |
| 333 | */ |
| 334 | extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...); |
| 335 | |
Al Viro | 02125a8 | 2011-12-05 08:43:34 -0500 | [diff] [blame] | 336 | extern char *__d_path(const struct path *, const struct path *, char *, int); |
| 337 | extern char *d_absolute_path(const struct path *, char *, int); |
Jan Engelhardt | 20d4fdc | 2008-06-09 16:40:36 -0700 | [diff] [blame] | 338 | extern char *d_path(const struct path *, char *, int); |
Nick Piggin | ec2447c | 2011-01-07 17:49:29 +1100 | [diff] [blame] | 339 | extern char *dentry_path_raw(struct dentry *, char *, int); |
Ram Pai | 6092d04 | 2008-03-27 13:06:20 +0100 | [diff] [blame] | 340 | extern char *dentry_path(struct dentry *, char *, int); |
Jan Blunck | cf28b48 | 2008-02-14 19:38:44 -0800 | [diff] [blame] | 341 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | /* Allocation counts.. */ |
| 343 | |
| 344 | /** |
Nick Piggin | dc0474b | 2011-01-07 17:49:43 +1100 | [diff] [blame] | 345 | * dget, dget_dlock - get a reference to a dentry |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | * @dentry: dentry to get a reference to |
| 347 | * |
| 348 | * Given a dentry or %NULL pointer increment the reference count |
| 349 | * if appropriate and return the dentry. A dentry will not be |
Nick Piggin | dc0474b | 2011-01-07 17:49:43 +1100 | [diff] [blame] | 350 | * destroyed when it has references. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | */ |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 352 | static inline struct dentry *dget_dlock(struct dentry *dentry) |
| 353 | { |
Nick Piggin | dc0474b | 2011-01-07 17:49:43 +1100 | [diff] [blame] | 354 | if (dentry) |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 355 | dentry->d_count++; |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 356 | return dentry; |
| 357 | } |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 358 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | static inline struct dentry *dget(struct dentry *dentry) |
| 360 | { |
| 361 | if (dentry) { |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 362 | spin_lock(&dentry->d_lock); |
| 363 | dget_dlock(dentry); |
| 364 | spin_unlock(&dentry->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | } |
| 366 | return dentry; |
| 367 | } |
| 368 | |
Nick Piggin | b7ab39f | 2011-01-07 17:49:32 +1100 | [diff] [blame] | 369 | extern struct dentry *dget_parent(struct dentry *dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | |
| 371 | /** |
| 372 | * d_unhashed - is dentry hashed |
| 373 | * @dentry: entry to check |
| 374 | * |
| 375 | * Returns true if the dentry passed is not currently hashed. |
| 376 | */ |
| 377 | |
| 378 | static inline int d_unhashed(struct dentry *dentry) |
| 379 | { |
Linus Torvalds | dea3667 | 2011-04-24 07:58:46 -0700 | [diff] [blame] | 380 | return hlist_bl_unhashed(&dentry->d_hash); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | } |
| 382 | |
Alexey Dobriyan | f3da392 | 2009-05-04 03:32:03 +0400 | [diff] [blame] | 383 | static inline int d_unlinked(struct dentry *dentry) |
| 384 | { |
| 385 | return d_unhashed(dentry) && !IS_ROOT(dentry); |
| 386 | } |
| 387 | |
Al Viro | d83c49f | 2010-04-30 17:17:09 -0400 | [diff] [blame] | 388 | static inline int cant_mount(struct dentry *dentry) |
| 389 | { |
| 390 | return (dentry->d_flags & DCACHE_CANT_MOUNT); |
| 391 | } |
| 392 | |
| 393 | static inline void dont_mount(struct dentry *dentry) |
| 394 | { |
| 395 | spin_lock(&dentry->d_lock); |
| 396 | dentry->d_flags |= DCACHE_CANT_MOUNT; |
| 397 | spin_unlock(&dentry->d_lock); |
| 398 | } |
| 399 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | extern void dput(struct dentry *); |
| 401 | |
David Howells | cc53ce5 | 2011-01-14 18:45:26 +0000 | [diff] [blame] | 402 | static inline bool d_managed(struct dentry *dentry) |
| 403 | { |
| 404 | return dentry->d_flags & DCACHE_MANAGED_DENTRY; |
| 405 | } |
| 406 | |
| 407 | static inline bool d_mountpoint(struct dentry *dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | { |
Nick Piggin | 5f57cbc | 2011-01-07 17:49:54 +1100 | [diff] [blame] | 409 | return dentry->d_flags & DCACHE_MOUNTED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | } |
| 411 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | extern int sysctl_vfs_cache_pressure; |
| 413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | #endif /* __LINUX_DCACHE_H */ |