parameterize BSIZE, FSIZE, and FRAG into fs_bsize, fs_fsize, and fs_frag

[unix-history] / usr / src / sys / ufs / ffs / fs.h

diff --git a/usr/src/sys/ufs/ffs/fs.h b/usr/src/sys/ufs/ffs/fs.h
index 99adbe1..1d4dfa9 100644 (file)
--- a/usr/src/sys/ufs/ffs/fs.h
+++ b/usr/src/sys/ufs/ffs/fs.h
@@ -1,6 +1,6 @@
 /* Copyright (c) 1981 Regents of the University of California */
 
 /* Copyright (c) 1981 Regents of the University of California */
 

-/*     fs.h    1.8     %G%     */
+/*     fs.h    1.9     %G%     */

 
 /*
  * Each disk drive contains some number of file systems.
 
 /*
  * Each disk drive contains some number of file systems.


@@ -17,31 +17,40 @@
  * For file system fs and a cylinder group number cg:
  *     [BBLOCK]        Boot sector and bad block information
  *     [SBLOCK]        Super-block
  * For file system fs and a cylinder group number cg:
  *     [BBLOCK]        Boot sector and bad block information
  *     [SBLOCK]        Super-block

- *     [CBLOCK]        Cylinder group block
- *     [IBLOCK..IBLOCK+fs.fs_ipg/INOPB)
+ *     [CBLOCK(fs)]    Cylinder group block
+ *     [IBLOCK(fs)..IBLOCK(fs)+fs.fs_ipg/INOPB(fs))

  *                     Inode blocks
  *                     Inode blocks

- *     [IBLOCK+fs.fs_ipg/INOPB..fs.fs_fpg/FRAG)
+ *     [IBLOCK(fs)+fs.fs_ipg/INOPB(fs)..fs.fs_fpg/fs.fs_frag)

  *                     Data blocks
  *                     Data blocks

- * The beginning of data blocks for cg in fs is also given by cgdmin(cg,fs).
+ * The beginning of data blocks for cg in fs is also given by
+ * the ``cgdmin(cg,fs)'' macro.
+ *
+ * The boot and super blocks are given in absolute disk addresses.
+ */
+#define        BBLOCK          ((daddr_t)(0 * (MAXBSIZE / DEV_BSIZE)))
+#define        SBLOCK          ((daddr_t)(1 * (MAXBSIZE / DEV_BSIZE)))
+/*
+ * The cylinder group and inode blocks are given in file system
+ * addresses, and hence must be converted to disk addresses by
+ * the ``fsbtodb(fs, bno)'' macro.

  */
  */

-#define        BBLOCK  ((daddr_t)(0*FRAG))
-#define        SBLOCK  ((daddr_t)(1*FRAG))
-#define        CBLOCK  ((daddr_t)(2*FRAG))
-#define        IBLOCK  ((daddr_t)(3*FRAG))
+#define        CBLOCK(fs)      ((daddr_t)(dbtofsb(fs, 2 * (MAXBSIZE / DEV_BSIZE))))
+#define        IBLOCK(fs)      ((daddr_t)(CBLOCK(fs) + (fs)->fs_frag))

 
 /*
 
 /*

- * Addresses stored in inodes are capable of addressing fragments of `blocks.'
- * File system blocks of size BSIZE can be broken into FRAG pieces,
- * each of which is addressible; these pieces may be sectors, or some
- * multiple of a sector size (e.g. 1k byte units).
+ * Addresses stored in inodes are capable of addressing fragments
+ * of `blocks'. File system blocks of at most size MAXBSIZE can 
+ * be optionally broken into 2, 4, or 8 pieces, each of which is
+ * addressible; these pieces may be DEV_BSIZE, or some multiple of
+ * a DEV_BSIZE unit.

  *
  *

- * Large files consist of exclusively large (BSIZE) data blocks.  To avoid
- * undue fragmentation, the last data block of a small file may be
- * allocated as only as many pieces
- * of a large block as are necessary.  The file system format retains
- * only a single pointer to such a fragment, which is a piece of a single
- * BSIZE block which has been divided.  The size of such a fragment is
- * determinable from information in the inode.
+ * Large files consist of exclusively large data blocks.  To avoid
+ * undue wasted disk space, the last data block of a small file may be
+ * allocated as only as many fragments of a large block as are
+ * necessary.  The file system format retains only a single pointer
+ * to such a fragment, which is a piece of a single large block that
+ * has been divided.  The size of such a fragment is determinable from
+ * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.

  *
  * The file system records space availability at the fragment level;
  * to determine block availability, aligned fragments are examined.
  *
  * The file system records space availability at the fragment level;
  * to determine block availability, aligned fragments are examined.


@@ -57,7 +66,10 @@
 /*
  * Information per cylinder group summarized in blocks allocated
  * from first cylinder group data blocks.  These blocks have to be
 /*
  * Information per cylinder group summarized in blocks allocated
  * from first cylinder group data blocks.  These blocks have to be

- * specially noticed in mkfs, icheck and fsck.
+ * read in from fs_csaddr (size fs_cssize) in addition to the
+ * super block.
+ * N.B. sizeof(struct csum) must be a power of two in order for
+ * the ``fs_cs'' macro to work (see below).

  */
 struct csum {
        long    cs_ndir;        /* number of directories */
  */
 struct csum {
        long    cs_ndir;        /* number of directories */


@@ -65,8 +77,6 @@ struct csum {
        long    cs_nifree;      /* number of free inodes */
        long    cs_nffree;      /* number of free frags */
 };
        long    cs_nifree;      /* number of free inodes */
        long    cs_nffree;      /* number of free frags */
 };

-#define        cssize(fs)      ((fs)->fs_ncg*sizeof(struct csum))
-#define        csaddr(fs)      (cgdmin(0, fs))

 
 /*
  * Each file system has a number of inodes statically allocated.
 
 /*
  * Each file system has a number of inodes statically allocated.


@@ -75,17 +85,28 @@ struct csum {
  */
 #define        NBPI    2048
 
  */
 #define        NBPI    2048
 

-#define        DESCPG  16                      /* desired fs_cpg */
-#define        MAXCPG  32                      /* maximum fs_cpg */
-/* MAXCPG is limited only to dimension an array in (struct cg); */
-/* it can be made larger as long as that structures size remains sane. */
+/*
+ * MINBSIZE is the smallest allowable block size.
+ * In order to insure that it is possible to create files of size
+ * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
+ * MINBSIZE must be big enough to hold a cylinder group block,
+ * thus changes to (struct cg) must keep its size within MINBSIZE.
+ * MAXCPG is limited only to dimension an array in (struct cg);
+ * it can be made larger as long as that structures size remains
+ * within the bounds dictated by MINBSIZE.
+ * Note that super blocks are always of size MAXBSIZE,
+ * and that MAXBSIZE must be >= MINBSIZE.
+ */
+#define MINBSIZE       4096
+#define        DESCPG          16      /* desired fs_cpg */
+#define        MAXCPG          32      /* maximum fs_cpg */

  
 /*
  * Super block for a file system.
  *
  
 /*
  * Super block for a file system.
  *

- * The super block is nominally located at disk block 1 although
- * this is naive due to bad blocks.  Inode 0 can't be used for normal
- * purposes, historically bad blocks were linked to inode 1,
+ * The super block is nominally located at disk block SBLOCK.
+ * Inode 0 can't be used for normal purposes,
+ * historically bad blocks were linked to inode 1,

  * thus the root inode is 2. (inode 1 is no longer used for
  * this purpose, however numerous dump tapes make this
  * assumption, so we are stuck with it)
  * thus the root inode is 2. (inode 1 is no longer used for
  * this purpose, however numerous dump tapes make this
  * assumption, so we are stuck with it)


@@ -101,7 +122,13 @@ struct     fs
        long    fs_size;                /* number of blocks in fs */
        long    fs_dsize;               /* number of data blocks in fs */
        long    fs_ncg;                 /* number of cylinder groups */
        long    fs_size;                /* number of blocks in fs */
        long    fs_dsize;               /* number of data blocks in fs */
        long    fs_ncg;                 /* number of cylinder groups */

+       long    fs_bsize;               /* size of basic blocks in fs */
+       long    fs_fsize;               /* size of frag blocks in fs */
+       long    fs_frag;                /* number of frags in a block in fs */
+       short   fs_minfree;             /* minimum percentage of free blocks */
+       short   fs_rotdelay;            /* num of ms for optimal next block */

 /* sizes determined by number of cylinder groups and their sizes */
 /* sizes determined by number of cylinder groups and their sizes */

+       daddr_t fs_csaddr;              /* blk addr of cyl grp summary area */

        long    fs_cssize;              /* size of cyl grp summary area */
        long    fs_cgsize;              /* cylinder group size */
 /* these fields should be derived from the hardware */
        long    fs_cssize;              /* size of cyl grp summary area */
        long    fs_cgsize;              /* cylinder group size */
 /* these fields should be derived from the hardware */


@@ -113,7 +140,7 @@ struct      fs
 /* these fields can be computed from the others */
        short   fs_cpg;                 /* cylinders per group */
        short   fs_ipg;                 /* inodes per group */
 /* these fields can be computed from the others */
        short   fs_cpg;                 /* cylinders per group */
        short   fs_ipg;                 /* inodes per group */

-       long    fs_fpg;                 /* blocks per group*FRAG */
+       long    fs_fpg;                 /* blocks per group * fs_frag */

 /* this data must be re-computed after crashes */
        struct  csum fs_cstotal;        /* cylinder summary information */
 /* these fields are cleared at mount time */
 /* this data must be re-computed after crashes */
        struct  csum fs_cstotal;        /* cylinder summary information */
 /* these fields are cleared at mount time */


@@ -127,8 +154,14 @@ struct     fs
        short   fs_rotbl[1];            /* list of blocks for each rotation */
 /* actually longer */
 };
        short   fs_rotbl[1];            /* list of blocks for each rotation */
 /* actually longer */
 };

-#define fs_cs(indx) fs_csp[(indx) / (BSIZE / sizeof(struct csum))] \
-                         [(indx) % (BSIZE / sizeof(struct csum))]
+
+/*
+ * convert cylinder group to base address of its global summary info.
+ * N.B. This macro assumes that sizeof(struct csum) is a power of two.
+ */
+#define fs_cs(fs, indx) \
+       fs_csp[(indx) / ((fs)->fs_bsize / sizeof(struct csum))] \
+       [(indx) % ((fs)->fs_bsize / sizeof(struct csum))]

 
 /*
  * Cylinder group macros to locate things in cylinder groups.
 
 /*
  * Cylinder group macros to locate things in cylinder groups.


@@ -139,32 +172,32 @@ struct    fs
 
 /* cylinder group to spare super block address */
 #define        cgsblock(c,fs)  \
 
 /* cylinder group to spare super block address */
 #define        cgsblock(c,fs)  \

-       (cgbase(c,fs) + SBLOCK)
+       (cgbase(c,fs) + dbtofsb(fs, SBLOCK))

 
 /* convert cylinder group to index of its cg block */
 #define        cgtod(c,fs)     \
 
 /* convert cylinder group to index of its cg block */
 #define        cgtod(c,fs)     \

-       (cgbase(c,fs) + CBLOCK)
+       (cgbase(c,fs) + CBLOCK(fs))

 
 /* give address of first inode block in cylinder group */
 #define        cgimin(c,fs)    \
 
 /* give address of first inode block in cylinder group */
 #define        cgimin(c,fs)    \

-       (cgbase(c,fs) + IBLOCK)
+       (cgbase(c,fs) + IBLOCK(fs))

 
 /* give address of first data block in cylinder group */
 
 /* give address of first data block in cylinder group */

-#define        cgdmin(c,fs)    (cgimin(c,fs) + (fs)->fs_ipg / INOPF)
+#define        cgdmin(c,fs)    (cgimin(c,fs) + (fs)->fs_ipg / INOPF(fs))

 
 /* turn inode number into cylinder group number */
 #define        itog(x,fs)      ((x)/(fs)->fs_ipg)
 
 
 /* turn inode number into cylinder group number */
 #define        itog(x,fs)      ((x)/(fs)->fs_ipg)
 

-/* turn inode number into disk block address */
-#define        itod(x,fs)      ((daddr_t)(cgimin(itog(x,fs),fs)+FRAG*((x)%(fs)->fs_ipg/INOPB)))
+/* turn inode number into file system block address */
+#define        itod(x,fs)      ((daddr_t)(cgimin(itog(x,fs),fs)+(fs)->fs_frag*((x)%(fs)->fs_ipg/INOPB(fs))))

 
 

-/* turn inode number into disk block offset */
-#define        itoo(x)         ((x)%INOPB)
+/* turn inode number into file system block offset */
+#define        itoo(x,fs)      ((x)%INOPB(fs))

 
 

-/* give cylinder group number for a disk block */
+/* give cylinder group number for a file system block */

 #define        dtog(d,fs)      ((d)/(fs)->fs_fpg)
 
 #define        dtog(d,fs)      ((d)/(fs)->fs_fpg)
 

-/* give cylinder group block number for a disk block */
+/* give cylinder group block number for a file system block */

 #define        dtogd(d,fs)     ((d)%(fs)->fs_fpg)
 
 /*
 #define        dtogd(d,fs)     ((d)%(fs)->fs_fpg)
 
 /*


@@ -186,7 +219,8 @@ struct      fs
  * Its size is derived from the size of blocks and the (struct cg) size,
  * by the number of remaining bits.
  */
  * Its size is derived from the size of blocks and the (struct cg) size,
  * by the number of remaining bits.
  */

-#define        MAXBPG  (NBBY*(BSIZE-(sizeof (struct cg)))/FRAG)
+#define        MAXBPG(fs) \
+       (NBBY*((fs)->fs_bsize-(sizeof (struct cg)))/(fs)->fs_frag)

 
 #define        CG_MAGIC        0x092752
 struct cg {
 
 #define        CG_MAGIC        0x092752
 struct cg {


@@ -200,7 +234,7 @@ struct      cg {
        long    cg_rotor;               /* position of last used block */
        long    cg_frotor;              /* position of last used frag */
        long    cg_irotor;              /* position of last used inode */
        long    cg_rotor;               /* position of last used block */
        long    cg_frotor;              /* position of last used frag */
        long    cg_irotor;              /* position of last used inode */

-       long    cg_frsum[FRAG];         /* counts of available frags */
+       long    cg_frsum[MAXFRAG];      /* counts of available frags */

        short   cg_b[MAXCPG][NRPOS];    /* positions of free blocks */
        char    cg_iused[MAXIPG/NBBY];  /* used inode map */
        char    cg_free[1];             /* free block map */
        short   cg_b[MAXCPG][NRPOS];    /* positions of free blocks */
        char    cg_iused[MAXIPG/NBBY];  /* used inode map */
        char    cg_free[1];             /* free block map */