The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/ufs/ffs/fs.h

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)fs.h        8.13 (Berkeley) 3/21/95
   32  * $FreeBSD: head/sys/ufs/ffs/fs.h 344552 2019-02-25 21:58:19Z mckusick $
   33  */
   34 
   35 #ifndef _UFS_FFS_FS_H_
   36 #define _UFS_FFS_FS_H_
   37 
   38 #include <sys/mount.h>
   39 #include <ufs/ufs/dinode.h>
   40 
   41 /*
   42  * Each disk drive contains some number of filesystems.
   43  * A filesystem consists of a number of cylinder groups.
   44  * Each cylinder group has inodes and data.
   45  *
   46  * A filesystem is described by its super-block, which in turn
   47  * describes the cylinder groups.  The super-block is critical
   48  * data and is replicated in each cylinder group to protect against
   49  * catastrophic loss.  This is done at `newfs' time and the critical
   50  * super-block data does not change, so the copies need not be
   51  * referenced further unless disaster strikes.
   52  *
   53  * For filesystem fs, the offsets of the various blocks of interest
   54  * are given in the super block as:
   55  *      [fs->fs_sblkno]         Super-block
   56  *      [fs->fs_cblkno]         Cylinder group block
   57  *      [fs->fs_iblkno]         Inode blocks
   58  *      [fs->fs_dblkno]         Data blocks
   59  * The beginning of cylinder group cg in fs, is given by
   60  * the ``cgbase(fs, cg)'' macro.
   61  *
   62  * Depending on the architecture and the media, the superblock may
   63  * reside in any one of four places. For tiny media where every block 
   64  * counts, it is placed at the very front of the partition. Historically,
   65  * UFS1 placed it 8K from the front to leave room for the disk label and
   66  * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
   67  * room for the disk label and a bigger bootstrap, and for really piggy
   68  * systems we check at 256K from the front if the first three fail. In
   69  * all cases the size of the superblock will be SBLOCKSIZE. All values are
   70  * given in byte-offset form, so they do not imply a sector size. The
   71  * SBLOCKSEARCH specifies the order in which the locations should be searched.
   72  */
   73 #define SBLOCK_FLOPPY        0
   74 #define SBLOCK_UFS1       8192
   75 #define SBLOCK_UFS2      65536
   76 #define SBLOCK_PIGGY    262144
   77 #define SBLOCKSIZE        8192
   78 #define SBLOCKSEARCH \
   79         { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
   80 
   81 /*
   82  * Max number of fragments per block. This value is NOT tweakable.
   83  */
   84 #define MAXFRAG         8
   85 
   86 /*
   87  * Addresses stored in inodes are capable of addressing fragments
   88  * of `blocks'. File system blocks of at most size MAXBSIZE can
   89  * be optionally broken into 2, 4, or 8 pieces, each of which is
   90  * addressable; these pieces may be DEV_BSIZE, or some multiple of
   91  * a DEV_BSIZE unit.
   92  *
   93  * Large files consist of exclusively large data blocks.  To avoid
   94  * undue wasted disk space, the last data block of a small file may be
   95  * allocated as only as many fragments of a large block as are
   96  * necessary.  The filesystem format retains only a single pointer
   97  * to such a fragment, which is a piece of a single large block that
   98  * has been divided.  The size of such a fragment is determinable from
   99  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
  100  *
  101  * The filesystem records space availability at the fragment level;
  102  * to determine block availability, aligned fragments are examined.
  103  */
  104 
  105 /*
  106  * MINBSIZE is the smallest allowable block size.
  107  * In order to insure that it is possible to create files of size
  108  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
  109  * MINBSIZE must be big enough to hold a cylinder group block,
  110  * thus changes to (struct cg) must keep its size within MINBSIZE.
  111  * Note that super blocks are always of size SBLOCKSIZE,
  112  * and that both SBLOCKSIZE and MAXBSIZE must be >= MINBSIZE.
  113  */
  114 #define MINBSIZE        4096
  115 
  116 /*
  117  * The path name on which the filesystem is mounted is maintained
  118  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
  119  * the super block for this name.
  120  */
  121 #define MAXMNTLEN       468
  122 
  123 /*
  124  * The volume name for this filesystem is maintained in fs_volname.
  125  * MAXVOLLEN defines the length of the buffer allocated.
  126  */
  127 #define MAXVOLLEN       32
  128 
  129 /*
  130  * There is a 128-byte region in the superblock reserved for in-core
  131  * pointers to summary information. Originally this included an array
  132  * of pointers to blocks of struct csum; now there are just a few
  133  * pointers and the remaining space is padded with fs_ocsp[].
  134  *
  135  * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
  136  * is taken away to point to a contiguous array of struct csum for
  137  * all cylinder groups; a second (fs_maxcluster) points to an array
  138  * of cluster sizes that is computed as cylinder groups are inspected,
  139  * and the third points to an array that tracks the creation of new
  140  * directories. A fourth pointer, fs_active, is used when creating
  141  * snapshots; it points to a bitmap of cylinder groups for which the
  142  * free-block bitmap has changed since the snapshot operation began.
  143  */
  144 #define NOCSPTRS        ((128 / sizeof(void *)) - 4)
  145 
  146 /*
  147  * A summary of contiguous blocks of various sizes is maintained
  148  * in each cylinder group. Normally this is set by the initial
  149  * value of fs_maxcontig. To conserve space, a maximum summary size
  150  * is set by FS_MAXCONTIG.
  151  */
  152 #define FS_MAXCONTIG    16
  153 
  154 /*
  155  * MINFREE gives the minimum acceptable percentage of filesystem
  156  * blocks which may be free. If the freelist drops below this level
  157  * only the superuser may continue to allocate blocks. This may
  158  * be set to 0 if no reserve of free blocks is deemed necessary,
  159  * however throughput drops by fifty percent if the filesystem
  160  * is run at between 95% and 100% full; thus the minimum default
  161  * value of fs_minfree is 5%. However, to get good clustering
  162  * performance, 10% is a better choice. hence we use 10% as our
  163  * default value. With 10% free space, fragmentation is not a
  164  * problem, so we choose to optimize for time.
  165  */
  166 #define MINFREE         8
  167 #define DEFAULTOPT      FS_OPTTIME
  168 
  169 /*
  170  * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
  171  * tune the layout preferences for directories within a filesystem.
  172  * His algorithm can be tuned by adjusting the following parameters
  173  * which tell the system the average file size and the average number
  174  * of files per directory. These defaults are well selected for typical
  175  * filesystems, but may need to be tuned for odd cases like filesystems
  176  * being used for squid caches or news spools.
  177  */
  178 #define AVFILESIZ       16384   /* expected average file size */
  179 #define AFPDIR          64      /* expected number of files per directory */
  180 
  181 /*
  182  * The maximum number of snapshot nodes that can be associated
  183  * with each filesystem. This limit affects only the number of
  184  * snapshot files that can be recorded within the superblock so
  185  * that they can be found when the filesystem is mounted. However,
  186  * maintaining too many will slow the filesystem performance, so
  187  * having this limit is a good idea.
  188  */
  189 #define FSMAXSNAP 20
  190 
  191 /*
  192  * Used to identify special blocks in snapshots:
  193  *
  194  * BLK_NOCOPY - A block that was unallocated at the time the snapshot
  195  *      was taken, hence does not need to be copied when written.
  196  * BLK_SNAP - A block held by another snapshot that is not needed by this
  197  *      snapshot. When the other snapshot is freed, the BLK_SNAP entries
  198  *      are converted to BLK_NOCOPY. These are needed to allow fsck to
  199  *      identify blocks that are in use by other snapshots (which are
  200  *      expunged from this snapshot).
  201  */
  202 #define BLK_NOCOPY ((ufs2_daddr_t)(1))
  203 #define BLK_SNAP ((ufs2_daddr_t)(2))
  204 
  205 /*
  206  * Sysctl values for the fast filesystem.
  207  */
  208 #define FFS_ADJ_REFCNT           1      /* adjust inode reference count */
  209 #define FFS_ADJ_BLKCNT           2      /* adjust inode used block count */
  210 #define FFS_BLK_FREE             3      /* free range of blocks in map */
  211 #define FFS_DIR_FREE             4      /* free specified dir inodes in map */
  212 #define FFS_FILE_FREE            5      /* free specified file inodes in map */
  213 #define FFS_SET_FLAGS            6      /* set filesystem flags */
  214 #define FFS_ADJ_NDIR             7      /* adjust number of directories */
  215 #define FFS_ADJ_NBFREE           8      /* adjust number of free blocks */
  216 #define FFS_ADJ_NIFREE           9      /* adjust number of free inodes */
  217 #define FFS_ADJ_NFFREE          10      /* adjust number of free frags */
  218 #define FFS_ADJ_NUMCLUSTERS     11      /* adjust number of free clusters */
  219 #define FFS_SET_CWD             12      /* set current directory */
  220 #define FFS_SET_DOTDOT          13      /* set inode number for ".." */
  221 #define FFS_UNLINK              14      /* remove a name in the filesystem */
  222 #define FFS_SET_INODE           15      /* update an on-disk inode */
  223 #define FFS_SET_BUFOUTPUT       16      /* set buffered writing on descriptor */
  224 #define FFS_SET_SIZE            17      /* set inode size */
  225 #define FFS_MAXID               17      /* number of valid ffs ids */
  226 
  227 /*
  228  * Command structure passed in to the filesystem to adjust filesystem values.
  229  */
  230 #define FFS_CMD_VERSION         0x19790518      /* version ID */
  231 struct fsck_cmd {
  232         int32_t version;        /* version of command structure */
  233         int32_t handle;         /* reference to filesystem to be changed */
  234         int64_t value;          /* inode or block number to be affected */
  235         int64_t size;           /* amount or range to be adjusted */
  236         int64_t spare;          /* reserved for future use */
  237 };
  238 
  239 /*
  240  * A recovery structure placed at the end of the boot block area by newfs
  241  * that can be used by fsck to search for alternate superblocks.
  242  */
  243 struct fsrecovery {
  244         int32_t fsr_magic;      /* magic number */
  245         int32_t fsr_fsbtodb;    /* fsbtodb and dbtofsb shift constant */
  246         int32_t fsr_sblkno;     /* offset of super-block in filesys */
  247         int32_t fsr_fpg;        /* blocks per group * fs_frag */
  248         u_int32_t fsr_ncg;      /* number of cylinder groups */
  249 };
  250 
  251 /*
  252  * Per cylinder group information; summarized in blocks allocated
  253  * from first cylinder group data blocks.  These blocks have to be
  254  * read in from fs_csaddr (size fs_cssize) in addition to the
  255  * super block.
  256  */
  257 struct csum {
  258         int32_t cs_ndir;                /* number of directories */
  259         int32_t cs_nbfree;              /* number of free blocks */
  260         int32_t cs_nifree;              /* number of free inodes */
  261         int32_t cs_nffree;              /* number of free frags */
  262 };
  263 struct csum_total {
  264         int64_t cs_ndir;                /* number of directories */
  265         int64_t cs_nbfree;              /* number of free blocks */
  266         int64_t cs_nifree;              /* number of free inodes */
  267         int64_t cs_nffree;              /* number of free frags */
  268         int64_t cs_numclusters;         /* number of free clusters */
  269         int64_t cs_spare[3];            /* future expansion */
  270 };
  271 
  272 /*
  273  * Super block for an FFS filesystem.
  274  */
  275 struct fs {
  276         int32_t  fs_firstfield;         /* historic filesystem linked list, */
  277         int32_t  fs_unused_1;           /*     used for incore super blocks */
  278         int32_t  fs_sblkno;             /* offset of super-block in filesys */
  279         int32_t  fs_cblkno;             /* offset of cyl-block in filesys */
  280         int32_t  fs_iblkno;             /* offset of inode-blocks in filesys */
  281         int32_t  fs_dblkno;             /* offset of first data after cg */
  282         int32_t  fs_old_cgoffset;       /* cylinder group offset in cylinder */
  283         int32_t  fs_old_cgmask;         /* used to calc mod fs_ntrak */
  284         int32_t  fs_old_time;           /* last time written */
  285         int32_t  fs_old_size;           /* number of blocks in fs */
  286         int32_t  fs_old_dsize;          /* number of data blocks in fs */
  287         u_int32_t fs_ncg;               /* number of cylinder groups */
  288         int32_t  fs_bsize;              /* size of basic blocks in fs */
  289         int32_t  fs_fsize;              /* size of frag blocks in fs */
  290         int32_t  fs_frag;               /* number of frags in a block in fs */
  291 /* these are configuration parameters */
  292         int32_t  fs_minfree;            /* minimum percentage of free blocks */
  293         int32_t  fs_old_rotdelay;       /* num of ms for optimal next block */
  294         int32_t  fs_old_rps;            /* disk revolutions per second */
  295 /* these fields can be computed from the others */
  296         int32_t  fs_bmask;              /* ``blkoff'' calc of blk offsets */
  297         int32_t  fs_fmask;              /* ``fragoff'' calc of frag offsets */
  298         int32_t  fs_bshift;             /* ``lblkno'' calc of logical blkno */
  299         int32_t  fs_fshift;             /* ``numfrags'' calc number of frags */
  300 /* these are configuration parameters */
  301         int32_t  fs_maxcontig;          /* max number of contiguous blks */
  302         int32_t  fs_maxbpg;             /* max number of blks per cyl group */
  303 /* these fields can be computed from the others */
  304         int32_t  fs_fragshift;          /* block to frag shift */
  305         int32_t  fs_fsbtodb;            /* fsbtodb and dbtofsb shift constant */
  306         int32_t  fs_sbsize;             /* actual size of super block */
  307         int32_t  fs_spare1[2];          /* old fs_csmask */
  308                                         /* old fs_csshift */
  309         int32_t  fs_nindir;             /* value of NINDIR */
  310         u_int32_t fs_inopb;             /* value of INOPB */
  311         int32_t  fs_old_nspf;           /* value of NSPF */
  312 /* yet another configuration parameter */
  313         int32_t  fs_optim;              /* optimization preference, see below */
  314         int32_t  fs_old_npsect;         /* # sectors/track including spares */
  315         int32_t  fs_old_interleave;     /* hardware sector interleave */
  316         int32_t  fs_old_trackskew;      /* sector 0 skew, per track */
  317         int32_t  fs_id[2];              /* unique filesystem id */
  318 /* sizes determined by number of cylinder groups and their sizes */
  319         int32_t  fs_old_csaddr;         /* blk addr of cyl grp summary area */
  320         int32_t  fs_cssize;             /* size of cyl grp summary area */
  321         int32_t  fs_cgsize;             /* cylinder group size */
  322         int32_t  fs_spare2;             /* old fs_ntrak */
  323         int32_t  fs_old_nsect;          /* sectors per track */
  324         int32_t  fs_old_spc;            /* sectors per cylinder */
  325         int32_t  fs_old_ncyl;           /* cylinders in filesystem */
  326         int32_t  fs_old_cpg;            /* cylinders per group */
  327         u_int32_t fs_ipg;               /* inodes per group */
  328         int32_t  fs_fpg;                /* blocks per group * fs_frag */
  329 /* this data must be re-computed after crashes */
  330         struct  csum fs_old_cstotal;    /* cylinder summary information */
  331 /* these fields are cleared at mount time */
  332         int8_t   fs_fmod;               /* super block modified flag */
  333         int8_t   fs_clean;              /* filesystem is clean flag */
  334         int8_t   fs_ronly;              /* mounted read-only flag */
  335         int8_t   fs_old_flags;          /* old FS_ flags */
  336         u_char   fs_fsmnt[MAXMNTLEN];   /* name mounted on */
  337         u_char   fs_volname[MAXVOLLEN]; /* volume name */
  338         u_int64_t fs_swuid;             /* system-wide uid */
  339         int32_t  fs_pad;                /* due to alignment of fs_swuid */
  340 /* these fields retain the current block allocation info */
  341         int32_t  fs_cgrotor;            /* last cg searched */
  342         void    *fs_ocsp[NOCSPTRS];     /* padding; was list of fs_cs buffers */
  343         u_int8_t *fs_contigdirs;        /* (u) # of contig. allocated dirs */
  344         struct  csum *fs_csp;           /* (u) cg summary info buffer */
  345         int32_t *fs_maxcluster;         /* (u) max cluster in each cyl group */
  346         u_int   *fs_active;             /* (u) used by snapshots to track fs */
  347         int32_t  fs_old_cpc;            /* cyl per cycle in postbl */
  348         int32_t  fs_maxbsize;           /* maximum blocking factor permitted */
  349         int64_t  fs_unrefs;             /* number of unreferenced inodes */
  350         int64_t  fs_providersize;       /* size of underlying GEOM provider */
  351         int64_t  fs_metaspace;          /* size of area reserved for metadata */
  352         int64_t  fs_sparecon64[13];     /* old rotation block list head */
  353         int64_t  fs_sblockactualloc;    /* byte offset of this superblock */
  354         int64_t  fs_sblockloc;          /* byte offset of standard superblock */
  355         struct  csum_total fs_cstotal;  /* (u) cylinder summary information */
  356         ufs_time_t fs_time;             /* last time written */
  357         int64_t  fs_size;               /* number of blocks in fs */
  358         int64_t  fs_dsize;              /* number of data blocks in fs */
  359         ufs2_daddr_t fs_csaddr;         /* blk addr of cyl grp summary area */
  360         int64_t  fs_pendingblocks;      /* (u) blocks being freed */
  361         u_int32_t fs_pendinginodes;     /* (u) inodes being freed */
  362         uint32_t fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
  363         u_int32_t fs_avgfilesize;       /* expected average file size */
  364         u_int32_t fs_avgfpdir;          /* expected # of files per directory */
  365         int32_t  fs_save_cgsize;        /* save real cg size to use fs_bsize */
  366         ufs_time_t fs_mtime;            /* Last mount or fsck time. */
  367         int32_t  fs_sujfree;            /* SUJ free list */
  368         int32_t  fs_sparecon32[21];     /* reserved for future constants */
  369         u_int32_t fs_ckhash;            /* if CK_SUPERBLOCK, its check-hash */
  370         u_int32_t fs_metackhash;        /* metadata check-hash, see CK_ below */
  371         int32_t  fs_flags;              /* see FS_ flags below */
  372         int32_t  fs_contigsumsize;      /* size of cluster summary array */ 
  373         int32_t  fs_maxsymlinklen;      /* max length of an internal symlink */
  374         int32_t  fs_old_inodefmt;       /* format of on-disk inodes */
  375         u_int64_t fs_maxfilesize;       /* maximum representable file size */
  376         int64_t  fs_qbmask;             /* ~fs_bmask for use with 64-bit size */
  377         int64_t  fs_qfmask;             /* ~fs_fmask for use with 64-bit size */
  378         int32_t  fs_state;              /* validate fs_clean field */
  379         int32_t  fs_old_postblformat;   /* format of positional layout tables */
  380         int32_t  fs_old_nrpos;          /* number of rotational positions */
  381         int32_t  fs_spare5[2];          /* old fs_postbloff */
  382                                         /* old fs_rotbloff */
  383         int32_t  fs_magic;              /* magic number */
  384 };
  385 
  386 /* Sanity checking. */
  387 #ifdef CTASSERT
  388 CTASSERT(sizeof(struct fs) == 1376);
  389 #endif
  390 
  391 /*
  392  * Filesystem identification
  393  */
  394 #define FS_UFS1_MAGIC   0x011954        /* UFS1 fast filesystem magic number */
  395 #define FS_UFS2_MAGIC   0x19540119      /* UFS2 fast filesystem magic number */
  396 #define FS_BAD_MAGIC    0x19960408      /* UFS incomplete newfs magic number */
  397 #define FS_42INODEFMT   -1              /* 4.2BSD inode format */
  398 #define FS_44INODEFMT   2               /* 4.4BSD inode format */
  399 
  400 /*
  401  * Preference for optimization.
  402  */
  403 #define FS_OPTTIME      0       /* minimize allocation time */
  404 #define FS_OPTSPACE     1       /* minimize disk fragmentation */
  405 
  406 /*
  407  * Filesystem flags.
  408  *
  409  * The FS_UNCLEAN flag is set by the kernel when the filesystem was
  410  * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates
  411  * that the filesystem should be managed by the soft updates code.
  412  * Note that the FS_NEEDSFSCK flag is set and cleared only by the
  413  * fsck utility. It is set when background fsck finds an unexpected
  414  * inconsistency which requires a traditional foreground fsck to be
  415  * run. Such inconsistencies should only be found after an uncorrectable
  416  * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when
  417  * it has successfully cleaned up the filesystem. The kernel uses this
  418  * flag to enforce that inconsistent filesystems be mounted read-only.
  419  * The FS_INDEXDIRS flag when set indicates that the kernel maintains
  420  * on-disk auxiliary indexes (such as B-trees) for speeding directory
  421  * accesses. Kernels that do not support auxiliary indices clear the
  422  * flag to indicate that the indices need to be rebuilt (by fsck) before
  423  * they can be used. When a filesystem is mounted, any flags not
  424  * included in FS_SUPPORTED are cleared. This lets newer features
  425  * know that the filesystem has been run on an older version of the
  426  * filesystem and thus that data structures associated with those
  427  * features are out-of-date and need to be rebuilt.
  428  *
  429  * FS_ACLS indicates that POSIX.1e ACLs are administratively enabled
  430  * for the file system, so they should be loaded from extended attributes,
  431  * observed for access control purposes, and be administered by object
  432  * owners.  FS_NFS4ACLS indicates that NFSv4 ACLs are administratively
  433  * enabled.  This flag is mutually exclusive with FS_ACLS.  FS_MULTILABEL
  434  * indicates that the TrustedBSD MAC Framework should attempt to back MAC
  435  * labels into extended attributes on the file system rather than maintain
  436  * a single mount label for all objects.
  437  */
  438 #define FS_UNCLEAN      0x00000001 /* filesystem not clean at mount */
  439 #define FS_DOSOFTDEP    0x00000002 /* filesystem using soft dependencies */
  440 #define FS_NEEDSFSCK    0x00000004 /* filesystem needs sync fsck before mount */
  441 #define FS_SUJ          0x00000008 /* Filesystem using softupdate journal */
  442 #define FS_ACLS         0x00000010 /* file system has POSIX.1e ACLs enabled */
  443 #define FS_MULTILABEL   0x00000020 /* file system is MAC multi-label */
  444 #define FS_GJOURNAL     0x00000040 /* gjournaled file system */
  445 #define FS_FLAGS_UPDATED 0x0000080 /* flags have been moved to new location */
  446 #define FS_NFS4ACLS     0x00000100 /* file system has NFSv4 ACLs enabled */
  447 #define FS_METACKHASH   0x00000200 /* kernel supports metadata check hashes */
  448 #define FS_TRIM         0x00000400 /* issue BIO_DELETE for deleted blocks */
  449 #define FS_SUPPORTED    0x00FFFFFF /* supported flags, others cleared at mount*/
  450 /*
  451  * Things that we may someday support, but currently do not.
  452  * These flags are all cleared so we know if we ran on a kernel
  453  * that does not support them.
  454  */
  455 #define FS_INDEXDIRS    0x01000000 /* kernel supports indexed directories */
  456 #define FS_VARBLKSIZE   0x02000000 /* kernel supports variable block sizes */
  457 #define FS_COOLOPT1     0x04000000 /* kernel supports cool option 1 */
  458 #define FS_COOLOPT2     0x08000000 /* kernel supports cool option 2 */
  459 #define FS_COOLOPT3     0x10000000 /* kernel supports cool option 3 */
  460 #define FS_COOLOPT4     0x20000000 /* kernel supports cool option 4 */
  461 #define FS_COOLOPT5     0x40000000 /* kernel supports cool option 5 */
  462 #define FS_COOLOPT6     0x80000000 /* kernel supports cool option 6 */
  463 
  464 /*
  465  * The fs_metackhash field indicates the types of metadata check-hash
  466  * that are maintained for a filesystem. Not all filesystems check-hash
  467  * all metadata.
  468  */
  469 #define CK_SUPERBLOCK   0x0001  /* the superblock */
  470 #define CK_CYLGRP       0x0002  /* the cylinder groups */
  471 #define CK_INODE        0x0004  /* inodes */
  472 #define CK_INDIR        0x0008  /* indirect blocks */
  473 #define CK_DIR          0x0010  /* directory contents */
  474 /*
  475  * The BX_FSPRIV buffer b_xflags are used to track types of data in buffers.
  476  */
  477 #define BX_SUPERBLOCK   0x00010000      /* superblock */
  478 #define BX_CYLGRP       0x00020000      /* cylinder groups */
  479 #define BX_INODE        0x00040000      /* inodes */
  480 #define BX_INDIR        0x00080000      /* indirect blocks */
  481 #define BX_DIR          0x00100000      /* directory contents */
  482 
  483 #define PRINT_UFS_BUF_XFLAGS "\2\25dir\24indir\23inode\22cylgrp\21superblock"
  484 
  485 /*
  486  * Macros to access bits in the fs_active array.
  487  */
  488 #define ACTIVECGNUM(fs, cg)     ((fs)->fs_active[(cg) / (NBBY * sizeof(int))])
  489 #define ACTIVECGOFF(cg)         (1 << ((cg) % (NBBY * sizeof(int))))
  490 #define ACTIVESET(fs, cg)       do {                                    \
  491         if ((fs)->fs_active)                                            \
  492                 ACTIVECGNUM((fs), (cg)) |= ACTIVECGOFF((cg));           \
  493 } while (0)
  494 #define ACTIVECLEAR(fs, cg)     do {                                    \
  495         if ((fs)->fs_active)                                            \
  496                 ACTIVECGNUM((fs), (cg)) &= ~ACTIVECGOFF((cg));          \
  497 } while (0)
  498 
  499 /*
  500  * The size of a cylinder group is calculated by CGSIZE. The maximum size
  501  * is limited by the fact that cylinder groups are at most one block.
  502  * Its size is derived from the size of the maps maintained in the
  503  * cylinder group and the (struct cg) size.
  504  */
  505 #define CGSIZE(fs) \
  506     /* base cg */       (sizeof(struct cg) + sizeof(int32_t) + \
  507     /* old btotoff */   (fs)->fs_old_cpg * sizeof(int32_t) + \
  508     /* old boff */      (fs)->fs_old_cpg * sizeof(u_int16_t) + \
  509     /* inode map */     howmany((fs)->fs_ipg, NBBY) + \
  510     /* block map */     howmany((fs)->fs_fpg, NBBY) +\
  511     /* if present */    ((fs)->fs_contigsumsize <= 0 ? 0 : \
  512     /* cluster sum */   (fs)->fs_contigsumsize * sizeof(int32_t) + \
  513     /* cluster map */   howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))
  514 
  515 /*
  516  * The minimal number of cylinder groups that should be created.
  517  */
  518 #define MINCYLGRPS      4
  519 
  520 /*
  521  * Convert cylinder group to base address of its global summary info.
  522  */
  523 #define fs_cs(fs, indx) fs_csp[indx]
  524 
  525 /*
  526  * Cylinder group block for a filesystem.
  527  */
  528 #define CG_MAGIC        0x090255
  529 struct cg {
  530         int32_t  cg_firstfield;         /* historic cyl groups linked list */
  531         int32_t  cg_magic;              /* magic number */
  532         int32_t  cg_old_time;           /* time last written */
  533         u_int32_t cg_cgx;               /* we are the cgx'th cylinder group */
  534         int16_t  cg_old_ncyl;           /* number of cyl's this cg */
  535         int16_t  cg_old_niblk;          /* number of inode blocks this cg */
  536         u_int32_t cg_ndblk;             /* number of data blocks this cg */
  537         struct   csum cg_cs;            /* cylinder summary information */
  538         u_int32_t cg_rotor;             /* position of last used block */
  539         u_int32_t cg_frotor;            /* position of last used frag */
  540         u_int32_t cg_irotor;            /* position of last used inode */
  541         u_int32_t cg_frsum[MAXFRAG];    /* counts of available frags */
  542         int32_t  cg_old_btotoff;        /* (int32) block totals per cylinder */
  543         int32_t  cg_old_boff;           /* (u_int16) free block positions */
  544         u_int32_t cg_iusedoff;          /* (u_int8) used inode map */
  545         u_int32_t cg_freeoff;           /* (u_int8) free block map */
  546         u_int32_t cg_nextfreeoff;       /* (u_int8) next available space */
  547         u_int32_t cg_clustersumoff;     /* (u_int32) counts of avail clusters */
  548         u_int32_t cg_clusteroff;                /* (u_int8) free cluster map */
  549         u_int32_t cg_nclusterblks;      /* number of clusters this cg */
  550         u_int32_t cg_niblk;             /* number of inode blocks this cg */
  551         u_int32_t cg_initediblk;                /* last initialized inode */
  552         u_int32_t cg_unrefs;            /* number of unreferenced inodes */
  553         int32_t  cg_sparecon32[1];      /* reserved for future use */
  554         u_int32_t cg_ckhash;            /* check-hash of this cg */
  555         ufs_time_t cg_time;             /* time last written */
  556         int64_t  cg_sparecon64[3];      /* reserved for future use */
  557         u_int8_t cg_space[1];           /* space for cylinder group maps */
  558 /* actually longer */
  559 };
  560 
  561 /*
  562  * Macros for access to cylinder group array structures
  563  */
  564 #define cg_chkmagic(cgp) ((cgp)->cg_magic == CG_MAGIC)
  565 #define cg_inosused(cgp) \
  566     ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))
  567 #define cg_blksfree(cgp) \
  568     ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))
  569 #define cg_clustersfree(cgp) \
  570     ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
  571 #define cg_clustersum(cgp) \
  572     ((int32_t *)((uintptr_t)(cgp) + (cgp)->cg_clustersumoff))
  573 
  574 /*
  575  * Turn filesystem block numbers into disk block addresses.
  576  * This maps filesystem blocks to device size blocks.
  577  */
  578 #define fsbtodb(fs, b)  ((daddr_t)(b) << (fs)->fs_fsbtodb)
  579 #define dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)
  580 
  581 /*
  582  * Cylinder group macros to locate things in cylinder groups.
  583  * They calc filesystem addresses of cylinder group data structures.
  584  */
  585 #define cgbase(fs, c)   (((ufs2_daddr_t)(fs)->fs_fpg) * (c))
  586 #define cgdata(fs, c)   (cgdmin(fs, c) + (fs)->fs_metaspace)    /* data zone */
  587 #define cgmeta(fs, c)   (cgdmin(fs, c))                         /* meta data */
  588 #define cgdmin(fs, c)   (cgstart(fs, c) + (fs)->fs_dblkno)      /* 1st data */
  589 #define cgimin(fs, c)   (cgstart(fs, c) + (fs)->fs_iblkno)      /* inode blk */
  590 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno)      /* super blk */
  591 #define cgtod(fs, c)    (cgstart(fs, c) + (fs)->fs_cblkno)      /* cg block */
  592 #define cgstart(fs, c)                                                  \
  593        ((fs)->fs_magic == FS_UFS2_MAGIC ? cgbase(fs, c) :               \
  594        (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask))))
  595 
  596 /*
  597  * Macros for handling inode numbers:
  598  *     inode number to filesystem block offset.
  599  *     inode number to cylinder group number.
  600  *     inode number to filesystem block address.
  601  */
  602 #define ino_to_cg(fs, x)        (((ino_t)(x)) / (fs)->fs_ipg)
  603 #define ino_to_fsba(fs, x)                                              \
  604         ((ufs2_daddr_t)(cgimin(fs, ino_to_cg(fs, (ino_t)(x))) +         \
  605             (blkstofrags((fs), ((((ino_t)(x)) % (fs)->fs_ipg) / INOPB(fs))))))
  606 #define ino_to_fsbo(fs, x)      (((ino_t)(x)) % INOPB(fs))
  607 
  608 /*
  609  * Give cylinder group number for a filesystem block.
  610  * Give cylinder group block number for a filesystem block.
  611  */
  612 #define dtog(fs, d)     ((d) / (fs)->fs_fpg)
  613 #define dtogd(fs, d)    ((d) % (fs)->fs_fpg)
  614 
  615 /*
  616  * Extract the bits for a block from a map.
  617  * Compute the cylinder and rotational position of a cyl block addr.
  618  */
  619 #define blkmap(fs, map, loc) \
  620     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
  621 
  622 /*
  623  * The following macros optimize certain frequently calculated
  624  * quantities by using shifts and masks in place of divisions
  625  * modulos and multiplications.
  626  */
  627 #define blkoff(fs, loc)         /* calculates (loc % fs->fs_bsize) */ \
  628         ((loc) & (fs)->fs_qbmask)
  629 #define fragoff(fs, loc)        /* calculates (loc % fs->fs_fsize) */ \
  630         ((loc) & (fs)->fs_qfmask)
  631 #define lfragtosize(fs, frag)   /* calculates ((off_t)frag * fs->fs_fsize) */ \
  632         (((off_t)(frag)) << (fs)->fs_fshift)
  633 #define lblktosize(fs, blk)     /* calculates ((off_t)blk * fs->fs_bsize) */ \
  634         (((off_t)(blk)) << (fs)->fs_bshift)
  635 /* Use this only when `blk' is known to be small, e.g., < UFS_NDADDR. */
  636 #define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
  637         ((blk) << (fs)->fs_bshift)
  638 #define lblkno(fs, loc)         /* calculates (loc / fs->fs_bsize) */ \
  639         ((loc) >> (fs)->fs_bshift)
  640 #define numfrags(fs, loc)       /* calculates (loc / fs->fs_fsize) */ \
  641         ((loc) >> (fs)->fs_fshift)
  642 #define blkroundup(fs, size)    /* calculates roundup(size, fs->fs_bsize) */ \
  643         (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
  644 #define fragroundup(fs, size)   /* calculates roundup(size, fs->fs_fsize) */ \
  645         (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
  646 #define fragstoblks(fs, frags)  /* calculates (frags / fs->fs_frag) */ \
  647         ((frags) >> (fs)->fs_fragshift)
  648 #define blkstofrags(fs, blks)   /* calculates (blks * fs->fs_frag) */ \
  649         ((blks) << (fs)->fs_fragshift)
  650 #define fragnum(fs, fsb)        /* calculates (fsb % fs->fs_frag) */ \
  651         ((fsb) & ((fs)->fs_frag - 1))
  652 #define blknum(fs, fsb)         /* calculates rounddown(fsb, fs->fs_frag) */ \
  653         ((fsb) &~ ((fs)->fs_frag - 1))
  654 
  655 /*
  656  * Determine the number of available frags given a
  657  * percentage to hold in reserve.
  658  */
  659 #define freespace(fs, percentreserved) \
  660         (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
  661         (fs)->fs_cstotal.cs_nffree - \
  662         (((off_t)((fs)->fs_dsize)) * (percentreserved) / 100))
  663 
  664 /*
  665  * Determining the size of a file block in the filesystem.
  666  */
  667 #define blksize(fs, ip, lbn) \
  668         (((lbn) >= UFS_NDADDR || (ip)->i_size >= \
  669             (uint64_t)smalllblktosize(fs, (lbn) + 1)) \
  670             ? (fs)->fs_bsize \
  671             : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
  672 #define sblksize(fs, size, lbn) \
  673         (((lbn) >= UFS_NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
  674           ? (fs)->fs_bsize \
  675           : (fragroundup(fs, blkoff(fs, (size)))))
  676 
  677 /*
  678  * Number of indirects in a filesystem block.
  679  */
  680 #define NINDIR(fs)      ((fs)->fs_nindir)
  681 
  682 /*
  683  * Indirect lbns are aligned on UFS_NDADDR addresses where single indirects
  684  * are the negated address of the lowest lbn reachable, double indirects
  685  * are this lbn - 1 and triple indirects are this lbn - 2.  This yields
  686  * an unusual bit order to determine level.
  687  */
  688 static inline int
  689 lbn_level(ufs_lbn_t lbn)
  690 {
  691         if (lbn >= 0)
  692                 return 0;
  693         switch (lbn & 0x3) {
  694         case 0:
  695                 return (0);
  696         case 1:
  697                 break;
  698         case 2:
  699                 return (2);
  700         case 3:
  701                 return (1);
  702         default:
  703                 break;
  704         }
  705         return (-1);
  706 }
  707 
  708 static inline ufs_lbn_t
  709 lbn_offset(struct fs *fs, int level)
  710 {
  711         ufs_lbn_t res;
  712 
  713         for (res = 1; level > 0; level--)
  714                 res *= NINDIR(fs);
  715         return (res);
  716 }
  717 
  718 /*
  719  * Number of inodes in a secondary storage block/fragment.
  720  */
  721 #define INOPB(fs)       ((fs)->fs_inopb)
  722 #define INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)
  723 
  724 /*
  725  * Softdep journal record format.
  726  */
  727 
  728 #define JOP_ADDREF      1       /* Add a reference to an inode. */
  729 #define JOP_REMREF      2       /* Remove a reference from an inode. */
  730 #define JOP_NEWBLK      3       /* Allocate a block. */
  731 #define JOP_FREEBLK     4       /* Free a block or a tree of blocks. */
  732 #define JOP_MVREF       5       /* Move a reference from one off to another. */
  733 #define JOP_TRUNC       6       /* Partial truncation record. */
  734 #define JOP_SYNC        7       /* fsync() complete record. */
  735 
  736 #define JREC_SIZE       32      /* Record and segment header size. */
  737 
  738 #define SUJ_MIN         (4 * 1024 * 1024)       /* Minimum journal size */
  739 #define SUJ_MAX         (32 * 1024 * 1024)      /* Maximum journal size */
  740 #define SUJ_FILE        ".sujournal"            /* Journal file name */
  741 
  742 /*
  743  * Size of the segment record header.  There is at most one for each disk
  744  * block in the journal.  The segment header is followed by an array of
  745  * records.  fsck depends on the first element in each record being 'op'
  746  * and the second being 'ino'.  Segments may span multiple disk blocks but
  747  * the header is present on each.
  748  */
  749 struct jsegrec {
  750         uint64_t        jsr_seq;        /* Our sequence number */
  751         uint64_t        jsr_oldest;     /* Oldest valid sequence number */
  752         uint16_t        jsr_cnt;        /* Count of valid records */
  753         uint16_t        jsr_blocks;     /* Count of device bsize blocks. */
  754         uint32_t        jsr_crc;        /* 32bit crc of the valid space */
  755         ufs_time_t      jsr_time;       /* timestamp for mount instance */
  756 };
  757 
  758 /*
  759  * Reference record.  Records a single link count modification.
  760  */
  761 struct jrefrec {
  762         uint32_t        jr_op;
  763         uint32_t        jr_ino;
  764         uint32_t        jr_parent;
  765         uint16_t        jr_nlink;
  766         uint16_t        jr_mode;
  767         int64_t         jr_diroff;
  768         uint64_t        jr_unused;
  769 };
  770 
  771 /*
  772  * Move record.  Records a reference moving within a directory block.  The
  773  * nlink is unchanged but we must search both locations.
  774  */
  775 struct jmvrec {
  776         uint32_t        jm_op;
  777         uint32_t        jm_ino;
  778         uint32_t        jm_parent;
  779         uint16_t        jm_unused;
  780         int64_t         jm_oldoff;
  781         int64_t         jm_newoff;
  782 };
  783 
  784 /*
  785  * Block record.  A set of frags or tree of blocks starting at an indirect are
  786  * freed or a set of frags are allocated.
  787  */
  788 struct jblkrec {
  789         uint32_t        jb_op;
  790         uint32_t        jb_ino;
  791         ufs2_daddr_t    jb_blkno;
  792         ufs_lbn_t       jb_lbn;
  793         uint16_t        jb_frags;
  794         uint16_t        jb_oldfrags;
  795         uint32_t        jb_unused;
  796 };
  797 
  798 /*
  799  * Truncation record.  Records a partial truncation so that it may be
  800  * completed at check time.  Also used for sync records.
  801  */
  802 struct jtrncrec {
  803         uint32_t        jt_op;
  804         uint32_t        jt_ino;
  805         int64_t         jt_size;
  806         uint32_t        jt_extsize;
  807         uint32_t        jt_pad[3];
  808 };
  809 
  810 union jrec {
  811         struct jsegrec  rec_jsegrec;
  812         struct jrefrec  rec_jrefrec;
  813         struct jmvrec   rec_jmvrec;
  814         struct jblkrec  rec_jblkrec;
  815         struct jtrncrec rec_jtrncrec;
  816 };
  817 
  818 #ifdef CTASSERT
  819 CTASSERT(sizeof(struct jsegrec) == JREC_SIZE);
  820 CTASSERT(sizeof(struct jrefrec) == JREC_SIZE);
  821 CTASSERT(sizeof(struct jmvrec) == JREC_SIZE);
  822 CTASSERT(sizeof(struct jblkrec) == JREC_SIZE);
  823 CTASSERT(sizeof(struct jtrncrec) == JREC_SIZE);
  824 CTASSERT(sizeof(union jrec) == JREC_SIZE);
  825 #endif
  826 
  827 extern int inside[], around[];
  828 extern u_char *fragtbl[];
  829 
  830 /*
  831  * IOCTLs used for filesystem write suspension.
  832  */
  833 #define UFSSUSPEND      _IOW('U', 1, fsid_t)
  834 #define UFSRESUME       _IO('U', 2)
  835 
  836 #endif

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