/*
- * Copyright (c) 1982 Regents of the University of California.
- * All rights reserved. The Berkeley software License Agreement
- * specifies the terms and conditions for redistribution.
+ * Copyright (c) 1982, 1986, 1993
+ * The Regents of the University of California. All rights reserved.
*
- * @(#)fs.h 6.5 (Berkeley) %G%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)fs.h 8.7 (Berkeley) 4/19/94
*/
/*
* A file system is described by its super-block, which in turn
* describes the cylinder groups. The super-block is critical
* data and is replicated in each cylinder group to protect against
- * catastrophic loss. This is done at mkfs time and the critical
+ * catastrophic loss. This is done at `newfs' time and the critical
* super-block data does not change, so the copies need not be
* referenced further unless disaster strikes.
*
* the ``cgbase(fs, cg)'' macro.
*
* The first boot and super blocks are given in absolute disk addresses.
+ * The byte-offset forms are preferred, as they don't imply a sector size.
*/
#define BBSIZE 8192
#define SBSIZE 8192
+#define BBOFF ((off_t)(0))
+#define SBOFF ((off_t)(BBOFF + BBSIZE))
#define BBLOCK ((daddr_t)(0))
#define SBLOCK ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
*
* The file system records space availability at the fragment level;
* to determine block availability, aligned fragments are examined.
- *
- * The root inode is the root of the file system.
- * Inode 0 can't be used for normal purposes and
- * 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)
- * The lost+found directory is given the next available
- * inode when it is created by ``mkfs''.
- */
-#define ROOTINO ((ino_t)2) /* i number of all roots */
-#define LOSTFOUNDINO (ROOTINO + 1)
-
-/*
- * Cylinder group related limits.
- *
- * For each cylinder we keep track of the availability of blocks at different
- * rotational positions, so that we can lay out the data to be picked
- * up with minimum rotational latency. NRPOS is the number of rotational
- * positions which we distinguish. With NRPOS 8 the resolution of our
- * summary information is 2ms for a typical 3600 rpm drive.
*/
-#define NRPOS 8 /* number distinct rotational positions */
-
-/*
- * MAXIPG bounds the number of inodes per cylinder group, and
- * is needed only to keep the structure simpler by having the
- * only a single variable size element (the free bit map).
- *
- * N.B.: MAXIPG must be a multiple of INOPB(fs).
- */
-#define MAXIPG 2048 /* max number inodes/cyl group */
/*
* MINBSIZE is the smallest allowable block 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 SBSIZE,
* and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
*/
#define MINBSIZE 4096
-#define MAXCPG 32 /* maximum fs_cpg */
/*
* The path name on which the file system is mounted is maintained
#define MAXMNTLEN 512
#define MAXCSBUFS 32
+/*
+ * A summary of contiguous blocks of various sizes is maintained
+ * in each cylinder group. Normally this is set by the initial
+ * value of fs_maxcontig. To conserve space, a maximum summary size
+ * is set by FS_MAXCONTIG.
+ */
+#define FS_MAXCONTIG 16
+
+/*
+ * MINFREE gives the minimum acceptable percentage of file system
+ * blocks which may be free. If the freelist drops below this level
+ * only the superuser may continue to allocate blocks. This may
+ * be set to 0 if no reserve of free blocks is deemed necessary,
+ * however throughput drops by fifty percent if the file system
+ * is run at between 95% and 100% full; thus the minimum default
+ * value of fs_minfree is 5%. However, to get good clustering
+ * performance, 10% is a better choice. hence we use 10% as our
+ * default value. With 10% free space, fragmentation is not a
+ * problem, so we choose to optimize for time.
+ */
+#define MINFREE 5
+#define DEFAULTOPT FS_OPTTIME
+
/*
* Per cylinder group information; summarized in blocks allocated
* from first cylinder group data blocks. These blocks have to be
/*
* Super block for a file system.
*/
-#define FS_MAGIC 0x011954
-struct fs
-{
+struct fs {
struct fs *fs_link; /* linked list of file systems */
struct fs *fs_rlink; /* used for incore super blocks */
daddr_t fs_sblkno; /* addr of super-block in filesys */
long fs_nindir; /* value of NINDIR */
long fs_inopb; /* value of INOPB */
long fs_nspf; /* value of NSPF */
+/* yet another configuration parameter */
long fs_optim; /* optimization preference, see below */
- long fs_sparecon[5]; /* reserved for future constants */
+/* these fields are derived from the hardware */
+ long fs_npsect; /* # sectors/track including spares */
+ long fs_interleave; /* hardware sector interleave */
+ long fs_trackskew; /* sector 0 skew, per track */
+ long fs_headswitch; /* head switch time, usec */
+ long fs_trkseek; /* track-to-track seek, usec */
/* 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 */
+/* these fields are derived from the hardware */
long fs_ntrak; /* tracks per cylinder */
long fs_nsect; /* sectors per track */
long fs_spc; /* sectors per cylinder */
long fs_cgrotor; /* last cg searched */
struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
long fs_cpc; /* cyl per cycle in postbl */
- short fs_postbl[MAXCPG][NRPOS];/* head of blocks for each rotation */
+ short fs_opostbl[16][8]; /* old rotation block list head */
+ long fs_sparecon[50]; /* reserved for future constants */
+ long fs_contigsumsize; /* size of cluster summary array */
+ long fs_maxsymlinklen; /* max length of an internal symlink */
+ long fs_inodefmt; /* format of on-disk inodes */
+ u_quad_t fs_maxfilesize; /* maximum representable file size */
+ quad_t fs_qbmask; /* ~fs_bmask - for use with quad size */
+ quad_t fs_qfmask; /* ~fs_fmask - for use with quad size */
+ long fs_state; /* validate fs_clean field */
+ long fs_postblformat; /* format of positional layout tables */
+ long fs_nrpos; /* number of rotational positions */
+ long fs_postbloff; /* (short) rotation block list head */
+ long fs_rotbloff; /* (u_char) blocks for each rotation */
long fs_magic; /* magic number */
- u_char fs_rotbl[1]; /* list of blocks for each rotation */
+ u_char fs_space[1]; /* list of blocks for each rotation */
/* actually longer */
};
+/*
+ * Filesystem idetification
+ */
+#define FS_MAGIC 0x011954 /* the fast filesystem magic number */
+#define FS_OKAY 0x7c269d38 /* superblock checksum */
+#define FS_42INODEFMT -1 /* 4.2BSD inode format */
+#define FS_44INODEFMT 2 /* 4.4BSD inode format */
/*
* Preference for optimization.
*/
#define FS_OPTTIME 0 /* minimize allocation time */
#define FS_OPTSPACE 1 /* minimize disk fragmentation */
+/*
+ * Rotational layout table format types
+ */
+#define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
+#define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
+/*
+ * Macros for access to superblock array structures
+ */
+#define fs_postbl(fs, cylno) \
+ (((fs)->fs_postblformat == FS_42POSTBLFMT) \
+ ? ((fs)->fs_opostbl[cylno]) \
+ : ((short *)((char *)(fs) + (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
+#define fs_rotbl(fs) \
+ (((fs)->fs_postblformat == FS_42POSTBLFMT) \
+ ? ((fs)->fs_space) \
+ : ((u_char *)((char *)(fs) + (fs)->fs_rotbloff)))
+
+/*
+ * The size of a cylinder group is calculated by CGSIZE. The maximum size
+ * is limited by the fact that cylinder groups are at most one block.
+ * Its size is derived from the size of the maps maintained in the
+ * cylinder group and the (struct cg) size.
+ */
+#define CGSIZE(fs) \
+ /* base cg */ (sizeof(struct cg) + sizeof(long) + \
+ /* blktot size */ (fs)->fs_cpg * sizeof(long) + \
+ /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(short) + \
+ /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
+ /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
+ /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
+ /* cluster sum */ (fs)->fs_contigsumsize * sizeof(long) + \
+ /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
+
/*
* Convert cylinder group to base address of its global summary info.
*
#define fs_cs(fs, indx) \
fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
-/*
- * MAXBPC bounds the size of the rotational layout tables and
- * is limited by the fact that the super block is of size SBSIZE.
- * The size of these tables is INVERSELY proportional to the block
- * size of the file system. It is aggravated by sector sizes that
- * are not powers of two, as this increases the number of cylinders
- * included before the rotational pattern repeats (fs_cpc).
- * Its size is derived from the number of bytes remaining in (struct fs)
- */
-#define MAXBPC (SBSIZE - sizeof (struct fs))
-
/*
* Cylinder group block for a file system.
*/
#define CG_MAGIC 0x090255
struct cg {
struct cg *cg_link; /* linked list of cyl groups */
- struct cg *cg_rlink; /* used for incore cyl groups */
+ long cg_magic; /* magic number */
time_t cg_time; /* time last written */
long cg_cgx; /* we are the cgx'th cylinder group */
short cg_ncyl; /* number of cyl's this cg */
long cg_frotor; /* position of last used frag */
long cg_irotor; /* position of last used inode */
long cg_frsum[MAXFRAG]; /* counts of available frags */
- long cg_btot[MAXCPG]; /* block totals per cylinder */
- short cg_b[MAXCPG][NRPOS]; /* positions of free blocks */
- char cg_iused[MAXIPG/NBBY]; /* used inode map */
- long cg_magic; /* magic number */
- u_char cg_free[1]; /* free block map */
+ long cg_btotoff; /* (long) block totals per cylinder */
+ long cg_boff; /* (short) free block positions */
+ long cg_iusedoff; /* (char) used inode map */
+ long cg_freeoff; /* (u_char) free block map */
+ long cg_nextfreeoff; /* (u_char) next available space */
+ long cg_clustersumoff; /* (long) counts of avail clusters */
+ long cg_clusteroff; /* (char) free cluster map */
+ long cg_nclusterblks; /* number of clusters this cg */
+ long cg_sparecon[13]; /* reserved for future use */
+ u_char cg_space[1]; /* space for cylinder group maps */
/* actually longer */
};
+/*
+ * Macros for access to cylinder group array structures
+ */
+#define cg_blktot(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_btot) \
+ : ((long *)((char *)(cgp) + (cgp)->cg_btotoff)))
+#define cg_blks(fs, cgp, cylno) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_b[cylno]) \
+ : ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
+#define cg_inosused(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_iused) \
+ : ((char *)((char *)(cgp) + (cgp)->cg_iusedoff)))
+#define cg_blksfree(cgp) \
+ (((cgp)->cg_magic != CG_MAGIC) \
+ ? (((struct ocg *)(cgp))->cg_free) \
+ : ((u_char *)((char *)(cgp) + (cgp)->cg_freeoff)))
+#define cg_chkmagic(cgp) \
+ ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
+#define cg_clustersfree(cgp) \
+ ((u_char *)((char *)(cgp) + (cgp)->cg_clusteroff))
+#define cg_clustersum(cgp) \
+ ((long *)((char *)(cgp) + (cgp)->cg_clustersumoff))
/*
- * MAXBPG bounds the number of blocks of data per cylinder group,
- * and is limited by the fact that cylinder groups are at most one block.
- * Its size is derived from the size of blocks and the (struct cg) size,
- * by the number of remaining bits.
+ * The following structure is defined
+ * for compatibility with old file systems.
*/
-#define MAXBPG(fs) \
- (fragstoblks((fs), (NBBY * ((fs)->fs_bsize - (sizeof (struct cg))))))
+struct ocg {
+ struct ocg *cg_link; /* linked list of cyl groups */
+ struct ocg *cg_rlink; /* used for incore cyl groups */
+ time_t cg_time; /* time last written */
+ long cg_cgx; /* we are the cgx'th cylinder group */
+ short cg_ncyl; /* number of cyl's this cg */
+ short cg_niblk; /* number of inode blocks this cg */
+ long cg_ndblk; /* number of data blocks this cg */
+ struct csum cg_cs; /* cylinder summary information */
+ 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[8]; /* counts of available frags */
+ long cg_btot[32]; /* block totals per cylinder */
+ short cg_b[32][8]; /* positions of free blocks */
+ char cg_iused[256]; /* used inode map */
+ long cg_magic; /* magic number */
+ u_char cg_free[1]; /* free block map */
+/* actually longer */
+};
/*
* Turn file system block numbers into disk block addresses.
* They calc file system addresses of cylinder group data structures.
*/
#define cgbase(fs, c) ((daddr_t)((fs)->fs_fpg * (c)))
-#define cgstart(fs, c) \
- (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
+#define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
+#define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
#define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
-#define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
-#define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
+#define cgstart(fs, c) \
+ (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
/*
* Macros for handling inode numbers:
* inode number to cylinder group number.
* inode number to file system block address.
*/
-#define itoo(fs, x) ((x) % INOPB(fs))
-#define itog(fs, x) ((x) / (fs)->fs_ipg)
-#define itod(fs, x) \
- ((daddr_t)(cgimin(fs, itog(fs, x)) + \
- (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
+#define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
+#define ino_to_fsba(fs, x) \
+ ((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
+ (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
+#define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
/*
* Give cylinder group number for a file system block.
#define blkmap(fs, map, loc) \
(((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
#define cbtocylno(fs, bno) \
- ((bno) * NSPF(fs) / (fs)->fs_spc)
+ ((bno) * NSPF(fs) / (fs)->fs_spc)
#define cbtorpos(fs, bno) \
- ((bno) * NSPF(fs) % (fs)->fs_nsect * NRPOS / (fs)->fs_nsect)
+ (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
+ (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
+ (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
/*
* The following macros optimize certain frequently calculated
* modulos and multiplications.
*/
#define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
- ((loc) & ~(fs)->fs_bmask)
+ ((loc) & (fs)->fs_qbmask)
#define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
- ((loc) & ~(fs)->fs_fmask)
+ ((loc) & (fs)->fs_qfmask)
+#define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
+ ((blk) << (fs)->fs_bshift)
#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
((loc) >> (fs)->fs_bshift)
#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
((loc) >> (fs)->fs_fshift)
#define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
- (((size) + (fs)->fs_bsize - 1) & (fs)->fs_bmask)
+ (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
- (((size) + (fs)->fs_fsize - 1) & (fs)->fs_fmask)
+ (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
#define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
((frags) >> (fs)->fs_fragshift)
#define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
*/
#define NINDIR(fs) ((fs)->fs_nindir)
-#ifdef KERNEL
-struct fs *getfs();
-struct fs *mountfs();
-#endif
+extern int inside[], around[];
+extern u_char *fragtbl[];