bsd/hfs/hfs_cnode.h

   1 /*
   2  * Copyright (c) 2002-2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #ifndef _HFS_CNODE_H_
  29 #define _HFS_CNODE_H_
  30
  31 #include <sys/appleapiopts.h>
  32
  33 #ifdef KERNEL
  34 #ifdef __APPLE_API_PRIVATE
  35 #include <sys/types.h>
  36 #include <sys/queue.h>
  37 #include <sys/stat.h>
  38 #include <sys/vnode.h>
  39 #include <sys/quota.h>
  40
  41 #include <kern/locks.h>
  42
  43 #include <hfs/hfs_catalog.h>
  44 #include <hfs/rangelist.h>
  45 #if HFS_COMPRESSION
  46 #include <sys/decmpfs.h>
  47 #endif
  48
  49 /*
  50  * The filefork is used to represent an HFS file fork (data or resource).
  51  * Reading or writing any of these fields requires holding cnode lock.
  52  */
  53 struct filefork {
  54         struct cnode   *ff_cp;               /* cnode associated with this fork */
  55         struct rl_head  ff_invalidranges;    /* Areas of disk that should read back as zeroes */
  56         union {
  57            void        *ffu_sysfileinfo;     /* additional info for system files */
  58            char        *ffu_symlinkptr;      /* symbolic link pathname */
  59         } ff_union;
  60         struct cat_fork ff_data;             /* fork data (size, extents) */
  61 };
  62 typedef struct filefork filefork_t;
  63
  64 /* Aliases for common fields */
  65 #define ff_size          ff_data.cf_size
  66 #define ff_new_size      ff_data.cf_new_size
  67 #define ff_clumpsize     ff_data.cf_clump
  68 #define ff_bytesread     ff_data.cf_bytesread
  69 #define ff_blocks        ff_data.cf_blocks
  70 #define ff_extents       ff_data.cf_extents
  71 #define ff_unallocblocks ff_data.cf_vblocks
  72
  73 #define ff_symlinkptr    ff_union.ffu_symlinkptr
  74 #define ff_sysfileinfo   ff_union.ffu_sysfileinfo
  75
  76
  77 /* The btree code still needs these... */
  78 #define fcbEOF           ff_size
  79 #define fcbExtents       ff_extents
  80 #define fcbBTCBPtr       ff_sysfileinfo
  81
  82 typedef u_int8_t atomicflag_t;
  83
  84
  85 /*
  86  * Hardlink Origin (for hardlinked directories).
  87  */
  88 struct linkorigin {
  89         TAILQ_ENTRY(linkorigin)  lo_link;  /* chain */
  90         void *  lo_thread;      /* thread that performed the lookup */
  91         cnid_t  lo_cnid;        /* hardlink's cnid */
  92         cnid_t  lo_parentcnid;  /* hardlink's parent cnid */
  93 };
  94 typedef struct linkorigin linkorigin_t;
  95
  96 #define MAX_CACHED_ORIGINS  10
  97 #define MAX_CACHED_FILE_ORIGINS 8
  98
  99 /*
 100  * The cnode is used to represent each active (or recently active)
 101  * file or directory in the HFS filesystem.
 102  *
 103  * Reading or writing any of these fields requires holding c_lock.
 104  */
 105 struct cnode {
 106         lck_rw_t                c_rwlock;       /* cnode's lock */
 107         void *                  c_lockowner;    /* cnode's lock owner (exclusive case only) */
 108         lck_rw_t                c_truncatelock; /* protects file from truncation during read/write */
 109         LIST_ENTRY(cnode)       c_hash;         /* cnode's hash chain */
 110         u_int32_t               c_flag;         /* cnode's runtime flags */
 111         u_int32_t               c_hflag;        /* cnode's flags for maintaining hash - protected by global hash lock */
 112         struct vnode            *c_vp;          /* vnode for data fork or dir */
 113         struct vnode            *c_rsrc_vp;     /* vnode for resource fork */
 114     struct dquot                *c_dquot[MAXQUOTAS]; /* cnode's quota info */
 115         u_int32_t               c_childhint;     /* catalog hint for children (small dirs only) */
 116         u_int32_t               c_dirthreadhint; /* catalog hint for directory's thread rec */
 117         struct cat_desc         c_desc;         /* cnode's descriptor */
 118         struct cat_attr         c_attr;         /* cnode's attributes */
 119         TAILQ_HEAD(hfs_originhead, linkorigin) c_originlist;  /* hardlink origin cache */
 120         TAILQ_HEAD(hfs_hinthead, directoryhint) c_hintlist;  /* readdir directory hint list */
 121         int16_t                 c_dirhinttag;   /* directory hint tag */
 122         union {
 123             int16_t     cu_dirhintcnt;          /* directory hint count */
 124             int16_t     cu_syslockcount;        /* system file use only */
 125         } c_union;
 126         u_int32_t               c_dirchangecnt; /* changes each insert/delete (in-core only) */
 127         struct filefork         *c_datafork;    /* cnode's data fork */
 128         struct filefork         *c_rsrcfork;    /* cnode's rsrc fork */
 129         atomicflag_t    c_touch_acctime;
 130         atomicflag_t    c_touch_chgtime;
 131         atomicflag_t    c_touch_modtime;
 132 #if HFS_COMPRESSION
 133         decmpfs_cnode  *c_decmp;
 134 #endif /* HFS_COMPRESSION */
 135 };
 136 typedef struct cnode cnode_t;
 137
 138 /* Aliases for common cnode fields */
 139 #define c_cnid          c_desc.cd_cnid
 140 #define c_hint          c_desc.cd_hint
 141 #define c_parentcnid    c_desc.cd_parentcnid
 142 #define c_encoding      c_desc.cd_encoding
 143
 144 #define c_fileid        c_attr.ca_fileid
 145 #define c_mode          c_attr.ca_mode
 146 #define c_linkcount     c_attr.ca_linkcount
 147 #define c_uid           c_attr.ca_uid
 148 #define c_gid           c_attr.ca_gid
 149 #define c_rdev          c_attr.ca_union1.cau_rdev
 150 #define c_atime         c_attr.ca_atime
 151 #define c_mtime         c_attr.ca_mtime
 152 #define c_ctime         c_attr.ca_ctime
 153 #define c_itime         c_attr.ca_itime
 154 #define c_btime         c_attr.ca_btime
 155 #define c_flags         c_attr.ca_flags
 156 #define c_finderinfo    c_attr.ca_finderinfo
 157 #define c_blocks        c_attr.ca_union2.cau_blocks
 158 #define c_entries       c_attr.ca_union2.cau_entries
 159 #define c_zftimeout     c_childhint
 160
 161 #define c_dirhintcnt    c_union.cu_dirhintcnt
 162 #define c_syslockcount  c_union.cu_syslockcount
 163
 164
 165 /* hash maintenance flags kept in c_hflag and protected by hfs_chash_mutex */
 166 #define H_ALLOC         0x00001 /* CNode is being allocated */
 167 #define H_ATTACH        0x00002 /* CNode is being attached to by another vnode */
 168 #define H_TRANSIT       0x00004 /* CNode is getting recycled  */
 169 #define H_WAITING       0x00008 /* CNode is being waited for */
 170
 171
 172 /* Runtime cnode flags (kept in c_flag) */
 173 #define C_NEED_RVNODE_PUT  0x00001  /* Need to do a vnode_put on c_rsrc_vp after the unlock */
 174 #define C_NEED_DVNODE_PUT  0x00002  /* Need to do a vnode_put on c_vp after the unlock */
 175 #define C_ZFWANTSYNC       0x00004  /* fsync requested and file has holes */
 176 #define C_FROMSYNC         0x00008  /* fsync was called from sync */
 177
 178 #define C_MODIFIED         0x00010  /* CNode has been modified */
 179 #define C_NOEXISTS         0x00020  /* CNode has been deleted, catalog entry is gone */
 180 #define C_DELETED          0x00040  /* CNode has been marked to be deleted */
 181 #define C_HARDLINK         0x00080  /* CNode is a hard link (file or dir) */
 182
 183 #define C_FORCEUPDATE      0x00100  /* force the catalog entry update */
 184 #define C_HASXATTRS        0x00200  /* cnode has extended attributes */
 185 #define C_NEG_ENTRIES      0x00400  /* directory has negative name entries */
 186 #define C_WARNED_RSRC      0x00800  /* cnode lookup warning has been issued */
 187
 188 #define C_NEED_DATA_SETSIZE  0x01000  /* Do a ubc_setsize(0) on c_rsrc_vp after the unlock */
 189 #define C_NEED_RSRC_SETSIZE  0x02000  /* Do a ubc_setsize(0) on c_vp after the unlock */
 190 #define C_DIR_MODIFICATION   0x04000  /* Directory is being modified, wait for lookups */
 191 #define C_ALWAYS_ZEROFILL    0x08000  /* Always zero-fill the file on an fsync */
 192
 193 #define ZFTIMELIMIT     (5 * 60)
 194
 195 /*
 196  * The following is the "invisible" bit from the fdFlags field
 197  * in the FndrFileInfo.
 198  */
 199 enum { kFinderInvisibleMask = 1 << 14 };
 200
 201
 202 /*
 203  * Convert between cnode pointers and vnode pointers
 204  */
 205 #define VTOC(vp)        ((struct cnode *)vnode_fsnode((vp)))
 206
 207 #define CTOV(cp,rsrc)   (((rsrc) && S_ISREG((cp)->c_mode)) ? \
 208                         (cp)->c_rsrc_vp : (cp)->c_vp)
 209
 210 /*
 211  * Convert between vnode pointers and file forks
 212  *
 213  * Note: no CTOF since that is ambiguous
 214  */
 215
 216 #define FTOC(fp)        ((fp)->ff_cp)
 217
 218 #define VTOF(vp)        ((vp) == VTOC((vp))->c_rsrc_vp ?        \
 219                          VTOC((vp))->c_rsrcfork :               \
 220                          VTOC((vp))->c_datafork)
 221
 222 #define VCTOF(vp, cp)   ((vp) == (cp)->c_rsrc_vp ?      \
 223                          (cp)->c_rsrcfork :             \
 224                          (cp)->c_datafork)
 225
 226 #define FTOV(fp)        ((fp) == FTOC(fp)->c_rsrcfork ?         \
 227                          FTOC(fp)->c_rsrc_vp :                  \
 228                          FTOC(fp)->c_vp)
 229
 230 /*
 231  * This is a helper function used for determining whether or not a cnode has become open
 232  * unlinked in between the time we acquired its vnode and the time we acquire the cnode lock
 233  * to start manipulating it.  Due to the SMP nature of VFS, it is probably necessary to
 234  * use this macro every time we acquire a cnode lock, as the content of the Cnode may have
 235  * been modified in betweeen the lookup and a VNOP.  Whether or not to call this is dependent
 236  * upon the VNOP in question.  Sometimes it is OK to use an open-unlinked file, for example, in,
 237  * reading.  But other times, such as on the source of a VNOP_RENAME, it should be disallowed.
 238  */
 239 int hfs_checkdeleted (struct cnode *cp);
 240
 241 /*
 242  * Test for a resource fork
 243  */
 244 #define FORK_IS_RSRC(fp)        ((fp) == FTOC(fp)->c_rsrcfork)
 245
 246 #define VNODE_IS_RSRC(vp)       ((vp) == VTOC((vp))->c_rsrc_vp)
 247
 248 #if HFS_COMPRESSION
 249 /*
 250  * VTOCMP(vp) returns a pointer to vp's decmpfs_cnode; this could be NULL
 251  * if the file is not compressed or if hfs_file_is_compressed() hasn't
 252  * yet been called on this file.
 253  */
 254 #define VTOCMP(vp) (VTOC((vp))->c_decmp)
 255 int hfs_file_is_compressed(struct cnode *cp, int skiplock);
 256 int hfs_uncompressed_size_of_compressed_file(struct hfsmount *hfsmp, struct vnode *vp, cnid_t fid, off_t *size, int skiplock);
 257 int hfs_hides_rsrc(vfs_context_t ctx, struct cnode *cp, int skiplock);
 258 int hfs_hides_xattr(vfs_context_t ctx, struct cnode *cp, const char *name, int skiplock);
 259 #endif
 260
 261 #define ATIME_ONDISK_ACCURACY   300
 262
 263
 264 /* This overlays the FileID portion of NFS file handles. */
 265 struct hfsfid {
 266         u_int32_t hfsfid_cnid;  /* Catalog node ID. */
 267         u_int32_t hfsfid_gen;   /* Generation number (create date). */
 268 };
 269
 270
 271 /* Get new default vnode */
 272 extern int hfs_getnewvnode(struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp,
 273                            struct cat_desc *descp, int flags, struct cat_attr *attrp,
 274                            struct cat_fork *forkp, struct vnode **vpp);
 275
 276
 277 #define GNV_WANTRSRC   0x01  /* Request the resource fork vnode. */
 278 #define GNV_SKIPLOCK   0x02  /* Skip taking the cnode lock (when getting resource fork). */
 279 #define GNV_CREATE     0x04  /* The vnode is for a newly created item. */
 280
 281
 282 /* Touch cnode times based on c_touch_xxx flags */
 283 extern void hfs_touchtimes(struct hfsmount *, struct cnode *);
 284
 285 /*
 286  * HFS cnode hash functions.
 287  */
 288 extern void  hfs_chashinit(void);
 289 extern void  hfs_chashinit_finish(struct hfsmount *hfsmp);
 290 extern void  hfs_delete_chash(struct hfsmount *hfsmp);
 291 extern int   hfs_chashremove(struct hfsmount *hfsmp, struct cnode *cp);
 292 extern void  hfs_chash_abort(struct hfsmount *hfsmp, struct cnode *cp);
 293 extern void  hfs_chash_rehash(struct hfsmount *hfsmp, struct cnode *cp1, struct cnode *cp2);
 294 extern void  hfs_chashwakeup(struct hfsmount *hfsmp, struct cnode *cp, int flags);
 295 extern void  hfs_chash_mark_in_transit(struct hfsmount *hfsmp, struct cnode *cp);
 296
 297 extern struct vnode * hfs_chash_getvnode(struct hfsmount *hfsmp, ino_t inum, int wantrsrc, int skiplock);
 298 extern struct cnode * hfs_chash_getcnode(struct hfsmount *hfsmp, ino_t inum, struct vnode **vpp, int wantrsrc, int skiplock);
 299 extern int hfs_chash_snoop(struct hfsmount *, ino_t, int (*)(const struct cat_desc *,
 300                             const struct cat_attr *, void *), void *);
 301 extern int hfs_valid_cnode(struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp, cnid_t cnid);
 302
 303 extern int hfs_chash_set_childlinkbit(struct hfsmount *hfsmp, cnid_t cnid);
 304
 305 /*
 306  * HFS cnode lock functions.
 307  *
 308  *  HFS Locking Order:
 309  *
 310  *  1. cnode truncate lock (if needed)
 311  *  2. cnode lock (in parent-child order if related, otherwise by address order)
 312  *  3. journal (if needed)
 313  *  4. system files (as needed)
 314  *       A. Catalog B-tree file
 315  *       B. Attributes B-tree file
 316  *       C. Startup file (if there is one)
 317  *       D. Allocation Bitmap file (always exclusive, supports recursion)
 318  *       E. Overflow Extents B-tree file (always exclusive, supports recursion)
 319  *  5. hfs mount point (always last)
 320  *
 321  */
 322 enum hfslocktype  {HFS_SHARED_LOCK = 1, HFS_EXCLUSIVE_LOCK = 2, HFS_FORCE_LOCK = 3};
 323 #define HFS_SHARED_OWNER  (void *)0xffffffff
 324
 325 extern int hfs_lock(struct cnode *, enum hfslocktype);
 326 extern int hfs_lockpair(struct cnode *, struct cnode *, enum hfslocktype);
 327 extern int hfs_lockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *,
 328                         enum hfslocktype, struct cnode **);
 329
 330 extern void hfs_unlock(struct cnode *);
 331 extern void hfs_unlockpair(struct cnode *, struct cnode *);
 332 extern void hfs_unlockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *);
 333
 334 extern void hfs_lock_truncate(struct cnode *, int);
 335 extern void hfs_unlock_truncate(struct cnode *, int);
 336
 337 #endif /* __APPLE_API_PRIVATE */
 338 #endif /* KERNEL */
 339
 340 #endif /* ! _HFS_CNODE_H_ */