bd3cde4571
Add primary cache management feature to libminixfs as mfs and ext2
currently do separately, remove cache code from mfs and ext2, and make
them use the libminixfs interface. This makes all fields of the buf
struct private to libminixfs and FS clients aren't supposed to access
them at all. Only the opaque 'void *data' field (the FS block contents,
used to be called bp) is to be accessed by the FS client.
The main purpose is to implement the interface to the 2ndary vm cache
just once, get rid of some code duplication, and add a little
abstraction to reduce the code inertia of the whole caching business.
Some minor sanity checking and prohibition done by mfs in this code
as removed from the generic primary cache code as a result:
- checking all inodes are not in use when allocating/resizing
the cache
- checking readonly filesystems aren't written to
- checking the superblock isn't written to on mounted filesystems
The minixfslib code relies on fs_blockstats() in the client filesystem to
return some FS usage information.
112 lines
3.4 KiB
C
112 lines
3.4 KiB
C
#include "fs.h"
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#include "buf.h"
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#include "inode.h"
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#include "super.h"
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/*===========================================================================*
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* no_sys *
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*===========================================================================*/
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int no_sys()
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{
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/* Somebody has used an illegal system call number */
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printf("no_sys: invalid call %d\n", req_nr);
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return(EINVAL);
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}
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/*===========================================================================*
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* conv2 *
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*===========================================================================*/
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unsigned conv2(norm, w)
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int norm; /* TRUE if no swap, FALSE for byte swap */
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int w; /* promotion of 16-bit word to be swapped */
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{
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/* Possibly swap a 16-bit word between 8086 and 68000 byte order. */
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if (norm) return( (unsigned) w & 0xFFFF);
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return( ((w&BYTE) << 8) | ( (w>>8) & BYTE));
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}
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/*===========================================================================*
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* conv4 *
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*===========================================================================*/
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long conv4(norm, x)
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int norm; /* TRUE if no swap, FALSE for byte swap */
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long x; /* 32-bit long to be byte swapped */
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{
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/* Possibly swap a 32-bit long between 8086 and 68000 byte order. */
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unsigned lo, hi;
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long l;
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if (norm) return(x); /* byte order was already ok */
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lo = conv2(FALSE, (int) x & 0xFFFF); /* low-order half, byte swapped */
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hi = conv2(FALSE, (int) (x>>16) & 0xFFFF); /* high-order half, swapped */
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l = ( (long) lo <<16) | hi;
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return(l);
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}
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/*===========================================================================*
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* clock_time *
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*===========================================================================*/
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time_t clock_time()
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{
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/* This routine returns the time in seconds since 1.1.1970. MINIX is an
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* astrophysically naive system that assumes the earth rotates at a constant
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* rate and that such things as leap seconds do not exist.
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*/
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register int k;
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clock_t uptime;
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time_t boottime;
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if ( (k=getuptime2(&uptime, &boottime)) != OK)
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panic("clock_time: getuptme2 failed: %d", k);
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return( (time_t) (boottime + (uptime/sys_hz())));
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}
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/*===========================================================================*
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* mfs_min *
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*===========================================================================*/
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int min(unsigned int l, unsigned int r)
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{
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if(r >= l) return(l);
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return(r);
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}
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/*===========================================================================*
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* mfs_nul *
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*===========================================================================*/
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void mfs_nul_f(char *file, int line, char *str, unsigned int len,
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unsigned int maxlen)
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{
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if(len < maxlen && str[len-1] != '\0') {
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printf("MFS %s:%d string (length %d, maxlen %d) not null-terminated\n",
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file, line, len, maxlen);
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}
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}
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#define MYASSERT(c) if(!(c)) { printf("MFS:%s:%d: sanity check: %s failed\n", \
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file, line, #c); panic("sanity check " #c " failed: %d", __LINE__); }
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/*===========================================================================*
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* sanity_check *
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*===========================================================================*/
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void sanitycheck(char *file, int line)
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{
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MYASSERT(SELF_E > 0);
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if(superblock.s_dev != NO_DEV) {
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MYASSERT(superblock.s_dev == fs_dev);
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MYASSERT(superblock.s_block_size == lmfs_fs_block_size());
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} else {
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MYASSERT(_MIN_BLOCK_SIZE == lmfs_fs_block_size());
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}
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}
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