6bbcab3ec4
- Remove unused includes. - Add include guards to headers. - Use unsigned variables in case they're never going to hold a negative value. This causes GCC's complaints to disappear and should make flexelint a lot happier, too. - Make functions private when they're used only within a module. - Remove unused variables. - Add casts where appropriate.
521 lines
18 KiB
C
521 lines
18 KiB
C
/* This file manages the inode table. There are procedures to allocate and
|
|
* deallocate inodes, acquire, erase, and release them, and read and write
|
|
* them from the disk.
|
|
*
|
|
* The entry points into this file are
|
|
* get_inode: search inode table for a given inode; if not there,
|
|
* read it
|
|
* put_inode: indicate that an inode is no longer needed in memory
|
|
* alloc_inode: allocate a new, unused inode
|
|
* wipe_inode: erase some fields of a newly allocated inode
|
|
* free_inode: mark an inode as available for a new file
|
|
* update_times: update atime, ctime, and mtime
|
|
* rw_inode: read a disk block and extract an inode, or corresp. write
|
|
* dup_inode: indicate that someone else is using an inode table entry
|
|
* find_inode: retrieve pointer to inode in inode cache
|
|
*
|
|
*/
|
|
|
|
#include "fs.h"
|
|
#include "buf.h"
|
|
#include "inode.h"
|
|
#include "super.h"
|
|
#include <minix/vfsif.h>
|
|
|
|
FORWARD _PROTOTYPE( void addhash_inode, (struct inode *node) );
|
|
|
|
FORWARD _PROTOTYPE( void free_inode, (dev_t dev, ino_t numb) );
|
|
FORWARD _PROTOTYPE( void new_icopy, (struct inode *rip, d2_inode *dip,
|
|
int direction, int norm));
|
|
FORWARD _PROTOTYPE( void old_icopy, (struct inode *rip, d1_inode *dip,
|
|
int direction, int norm));
|
|
FORWARD _PROTOTYPE( void unhash_inode, (struct inode *node) );
|
|
FORWARD _PROTOTYPE( void wipe_inode, (struct inode *rip) );
|
|
|
|
|
|
/*===========================================================================*
|
|
* fs_putnode *
|
|
*===========================================================================*/
|
|
PUBLIC int fs_putnode(void)
|
|
{
|
|
/* Find the inode specified by the request message and decrease its counter.*/
|
|
|
|
struct inode *rip;
|
|
int count;
|
|
|
|
rip = find_inode(fs_dev, (ino_t) fs_m_in.REQ_INODE_NR);
|
|
|
|
if(!rip) {
|
|
printf("%s:%d put_inode: inode #%ul dev: %d not found\n", __FILE__,
|
|
__LINE__, (ino_t) fs_m_in.REQ_INODE_NR, fs_dev);
|
|
panic("fs_putnode failed");
|
|
}
|
|
|
|
count = fs_m_in.REQ_COUNT;
|
|
if (count <= 0) {
|
|
printf("%s:%d put_inode: bad value for count: %d\n", __FILE__,
|
|
__LINE__, count);
|
|
panic("fs_putnode failed");
|
|
} else if(count > rip->i_count) {
|
|
printf("%s:%d put_inode: count too high: %d > %d\n", __FILE__,
|
|
__LINE__, count, rip->i_count);
|
|
panic("fs_putnode failed");
|
|
}
|
|
|
|
/* Decrease reference counter, but keep one reference; it will be consumed by
|
|
* put_inode(). */
|
|
rip->i_count -= count - 1;
|
|
put_inode(rip);
|
|
|
|
return(OK);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* init_inode_cache *
|
|
*===========================================================================*/
|
|
PUBLIC void init_inode_cache()
|
|
{
|
|
struct inode *rip;
|
|
struct inodelist *rlp;
|
|
|
|
inode_cache_hit = 0;
|
|
inode_cache_miss = 0;
|
|
|
|
/* init free/unused list */
|
|
TAILQ_INIT(&unused_inodes);
|
|
|
|
/* init hash lists */
|
|
for (rlp = &hash_inodes[0]; rlp < &hash_inodes[INODE_HASH_SIZE]; ++rlp)
|
|
LIST_INIT(rlp);
|
|
|
|
/* add free inodes to unused/free list */
|
|
for (rip = &inode[0]; rip < &inode[NR_INODES]; ++rip) {
|
|
rip->i_num = NO_ENTRY;
|
|
TAILQ_INSERT_HEAD(&unused_inodes, rip, i_unused);
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* addhash_inode *
|
|
*===========================================================================*/
|
|
PRIVATE void addhash_inode(struct inode *node)
|
|
{
|
|
int hashi = (int) (node->i_num & INODE_HASH_MASK);
|
|
|
|
/* insert into hash table */
|
|
LIST_INSERT_HEAD(&hash_inodes[hashi], node, i_hash);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* unhash_inode *
|
|
*===========================================================================*/
|
|
PRIVATE void unhash_inode(struct inode *node)
|
|
{
|
|
/* remove from hash table */
|
|
LIST_REMOVE(node, i_hash);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* get_inode *
|
|
*===========================================================================*/
|
|
PUBLIC struct inode *get_inode(
|
|
dev_t dev, /* device on which inode resides */
|
|
ino_t numb /* inode number */
|
|
)
|
|
{
|
|
/* Find the inode in the hash table. If it is not there, get a free inode
|
|
* load it from the disk if it's necessary and put on the hash list
|
|
*/
|
|
register struct inode *rip;
|
|
int hashi;
|
|
|
|
hashi = (int) (numb & INODE_HASH_MASK);
|
|
|
|
/* Search inode in the hash table */
|
|
LIST_FOREACH(rip, &hash_inodes[hashi], i_hash) {
|
|
if (rip->i_num == numb && rip->i_dev == dev) {
|
|
/* If unused, remove it from the unused/free list */
|
|
if (rip->i_count == 0) {
|
|
inode_cache_hit++;
|
|
TAILQ_REMOVE(&unused_inodes, rip, i_unused);
|
|
}
|
|
++rip->i_count;
|
|
return(rip);
|
|
}
|
|
}
|
|
|
|
inode_cache_miss++;
|
|
|
|
/* Inode is not on the hash, get a free one */
|
|
if (TAILQ_EMPTY(&unused_inodes)) {
|
|
err_code = ENFILE;
|
|
return(NULL);
|
|
}
|
|
rip = TAILQ_FIRST(&unused_inodes);
|
|
|
|
/* If not free unhash it */
|
|
if (rip->i_num != NO_ENTRY)
|
|
unhash_inode(rip);
|
|
|
|
/* Inode is not unused any more */
|
|
TAILQ_REMOVE(&unused_inodes, rip, i_unused);
|
|
|
|
/* Load the inode. */
|
|
rip->i_dev = dev;
|
|
rip->i_num = numb;
|
|
rip->i_count = 1;
|
|
if (dev != NO_DEV) rw_inode(rip, READING); /* get inode from disk */
|
|
rip->i_update = 0; /* all the times are initially up-to-date */
|
|
rip->i_zsearch = NO_ZONE; /* no zones searched for yet */
|
|
rip->i_mountpoint= FALSE;
|
|
|
|
/* Add to hash */
|
|
addhash_inode(rip);
|
|
|
|
return(rip);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* find_inode *
|
|
*===========================================================================*/
|
|
PUBLIC struct inode *find_inode(
|
|
dev_t dev, /* device on which inode resides */
|
|
ino_t numb /* inode number */
|
|
)
|
|
{
|
|
/* Find the inode specified by the inode and device number.
|
|
*/
|
|
struct inode *rip;
|
|
int hashi;
|
|
|
|
hashi = (int) (numb & INODE_HASH_MASK);
|
|
|
|
/* Search inode in the hash table */
|
|
LIST_FOREACH(rip, &hash_inodes[hashi], i_hash) {
|
|
if (rip->i_count > 0 && rip->i_num == numb && rip->i_dev == dev) {
|
|
return(rip);
|
|
}
|
|
}
|
|
|
|
return(NULL);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* put_inode *
|
|
*===========================================================================*/
|
|
PUBLIC void put_inode(rip)
|
|
register struct inode *rip; /* pointer to inode to be released */
|
|
{
|
|
/* The caller is no longer using this inode. If no one else is using it either
|
|
* write it back to the disk immediately. If it has no links, truncate it and
|
|
* return it to the pool of available inodes.
|
|
*/
|
|
|
|
if (rip == NULL) return; /* checking here is easier than in caller */
|
|
|
|
if (rip->i_count < 1)
|
|
panic("put_inode: i_count already below 1: %d", rip->i_count);
|
|
|
|
if (--rip->i_count == 0) { /* i_count == 0 means no one is using it now */
|
|
if (rip->i_nlinks == NO_LINK) {
|
|
/* i_nlinks == NO_LINK means free the inode. */
|
|
/* return all the disk blocks */
|
|
if (truncate_inode(rip, (off_t) 0) != OK) return;
|
|
rip->i_mode = I_NOT_ALLOC; /* clear I_TYPE field */
|
|
rip->i_dirt = DIRTY;
|
|
free_inode(rip->i_dev, rip->i_num);
|
|
}
|
|
|
|
rip->i_mountpoint = FALSE;
|
|
if (rip->i_dirt == DIRTY) rw_inode(rip, WRITING);
|
|
|
|
if (rip->i_nlinks == NO_LINK) {
|
|
/* free, put at the front of the LRU list */
|
|
unhash_inode(rip);
|
|
rip->i_num = NO_ENTRY;
|
|
TAILQ_INSERT_HEAD(&unused_inodes, rip, i_unused);
|
|
} else {
|
|
/* unused, put at the back of the LRU (cache it) */
|
|
TAILQ_INSERT_TAIL(&unused_inodes, rip, i_unused);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* alloc_inode *
|
|
*===========================================================================*/
|
|
PUBLIC struct inode *alloc_inode(dev_t dev, mode_t bits)
|
|
{
|
|
/* Allocate a free inode on 'dev', and return a pointer to it. */
|
|
|
|
register struct inode *rip;
|
|
register struct super_block *sp;
|
|
int major, minor, inumb;
|
|
bit_t b;
|
|
|
|
sp = get_super(dev); /* get pointer to super_block */
|
|
if (sp->s_rd_only) { /* can't allocate an inode on a read only device. */
|
|
err_code = EROFS;
|
|
return(NULL);
|
|
}
|
|
|
|
/* Acquire an inode from the bit map. */
|
|
b = alloc_bit(sp, IMAP, sp->s_isearch);
|
|
if (b == NO_BIT) {
|
|
err_code = ENFILE;
|
|
major = (int) (sp->s_dev >> MAJOR) & BYTE;
|
|
minor = (int) (sp->s_dev >> MINOR) & BYTE;
|
|
printf("Out of i-nodes on device %d/%d\n", major, minor);
|
|
return(NULL);
|
|
}
|
|
sp->s_isearch = b; /* next time start here */
|
|
inumb = (int) b; /* be careful not to pass unshort as param */
|
|
|
|
/* Try to acquire a slot in the inode table. */
|
|
if ((rip = get_inode(NO_DEV, inumb)) == NULL) {
|
|
/* No inode table slots available. Free the inode just allocated. */
|
|
free_bit(sp, IMAP, b);
|
|
} else {
|
|
/* An inode slot is available. Put the inode just allocated into it. */
|
|
rip->i_mode = bits; /* set up RWX bits */
|
|
rip->i_nlinks = NO_LINK; /* initial no links */
|
|
rip->i_uid = caller_uid; /* file's uid is owner's */
|
|
rip->i_gid = caller_gid; /* ditto group id */
|
|
rip->i_dev = dev; /* mark which device it is on */
|
|
rip->i_ndzones = sp->s_ndzones; /* number of direct zones */
|
|
rip->i_nindirs = sp->s_nindirs; /* number of indirect zones per blk*/
|
|
rip->i_sp = sp; /* pointer to super block */
|
|
|
|
/* Fields not cleared already are cleared in wipe_inode(). They have
|
|
* been put there because truncate() needs to clear the same fields if
|
|
* the file happens to be open while being truncated. It saves space
|
|
* not to repeat the code twice.
|
|
*/
|
|
wipe_inode(rip);
|
|
}
|
|
|
|
return(rip);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* wipe_inode *
|
|
*===========================================================================*/
|
|
PRIVATE void wipe_inode(rip)
|
|
register struct inode *rip; /* the inode to be erased */
|
|
{
|
|
/* Erase some fields in the inode. This function is called from alloc_inode()
|
|
* when a new inode is to be allocated, and from truncate(), when an existing
|
|
* inode is to be truncated.
|
|
*/
|
|
|
|
register int i;
|
|
|
|
rip->i_size = 0;
|
|
rip->i_update = ATIME | CTIME | MTIME; /* update all times later */
|
|
rip->i_dirt = DIRTY;
|
|
for (i = 0; i < V2_NR_TZONES; i++) rip->i_zone[i] = NO_ZONE;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* free_inode *
|
|
*===========================================================================*/
|
|
PRIVATE void free_inode(
|
|
dev_t dev, /* on which device is the inode? */
|
|
ino_t inumb /* number of the inode to be freed */
|
|
)
|
|
{
|
|
/* Return an inode to the pool of unallocated inodes. */
|
|
|
|
register struct super_block *sp;
|
|
bit_t b;
|
|
|
|
/* Locate the appropriate super_block. */
|
|
sp = get_super(dev);
|
|
if (inumb > sp->s_ninodes) return;
|
|
b = (bit_t) inumb;
|
|
free_bit(sp, IMAP, b);
|
|
if (b < sp->s_isearch) sp->s_isearch = b;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* update_times *
|
|
*===========================================================================*/
|
|
PUBLIC void update_times(rip)
|
|
register struct inode *rip; /* pointer to inode to be read/written */
|
|
{
|
|
/* Various system calls are required by the standard to update atime, ctime,
|
|
* or mtime. Since updating a time requires sending a message to the clock
|
|
* task--an expensive business--the times are marked for update by setting
|
|
* bits in i_update. When a stat, fstat, or sync is done, or an inode is
|
|
* released, update_times() may be called to actually fill in the times.
|
|
*/
|
|
|
|
time_t cur_time;
|
|
struct super_block *sp;
|
|
|
|
sp = rip->i_sp; /* get pointer to super block. */
|
|
if (sp->s_rd_only) return; /* no updates for read-only file systems */
|
|
|
|
cur_time = clock_time();
|
|
if (rip->i_update & ATIME) rip->i_atime = cur_time;
|
|
if (rip->i_update & CTIME) rip->i_ctime = cur_time;
|
|
if (rip->i_update & MTIME) rip->i_mtime = cur_time;
|
|
rip->i_update = 0; /* they are all up-to-date now */
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rw_inode *
|
|
*===========================================================================*/
|
|
PUBLIC void rw_inode(rip, rw_flag)
|
|
register struct inode *rip; /* pointer to inode to be read/written */
|
|
int rw_flag; /* READING or WRITING */
|
|
{
|
|
/* An entry in the inode table is to be copied to or from the disk. */
|
|
|
|
register struct buf *bp;
|
|
register struct super_block *sp;
|
|
d1_inode *dip;
|
|
d2_inode *dip2;
|
|
block_t b, offset;
|
|
|
|
/* Get the block where the inode resides. */
|
|
sp = get_super(rip->i_dev); /* get pointer to super block */
|
|
rip->i_sp = sp; /* inode must contain super block pointer */
|
|
offset = START_BLOCK + sp->s_imap_blocks + sp->s_zmap_blocks;
|
|
b = (block_t) (rip->i_num - 1)/sp->s_inodes_per_block + offset;
|
|
bp = get_block(rip->i_dev, b, NORMAL);
|
|
dip = bp->b_v1_ino + (rip->i_num - 1) % V1_INODES_PER_BLOCK;
|
|
dip2 = bp->b_v2_ino + (rip->i_num - 1) %
|
|
V2_INODES_PER_BLOCK(sp->s_block_size);
|
|
|
|
/* Do the read or write. */
|
|
if (rw_flag == WRITING) {
|
|
if (rip->i_update) update_times(rip); /* times need updating */
|
|
if (sp->s_rd_only == FALSE) bp->b_dirt = DIRTY;
|
|
}
|
|
|
|
/* Copy the inode from the disk block to the in-core table or vice versa.
|
|
* If the fourth parameter below is FALSE, the bytes are swapped.
|
|
*/
|
|
if (sp->s_version == V1)
|
|
old_icopy(rip, dip, rw_flag, sp->s_native);
|
|
else
|
|
new_icopy(rip, dip2, rw_flag, sp->s_native);
|
|
|
|
put_block(bp, INODE_BLOCK);
|
|
rip->i_dirt = CLEAN;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* old_icopy *
|
|
*===========================================================================*/
|
|
PRIVATE void old_icopy(rip, dip, direction, norm)
|
|
register struct inode *rip; /* pointer to the in-core inode struct */
|
|
register d1_inode *dip; /* pointer to the d1_inode inode struct */
|
|
int direction; /* READING (from disk) or WRITING (to disk) */
|
|
int norm; /* TRUE = do not swap bytes; FALSE = swap */
|
|
{
|
|
/* The V1.x IBM disk, the V1.x 68000 disk, and the V2 disk (same for IBM and
|
|
* 68000) all have different inode layouts. When an inode is read or written
|
|
* this routine handles the conversions so that the information in the inode
|
|
* table is independent of the disk structure from which the inode came.
|
|
* The old_icopy routine copies to and from V1 disks.
|
|
*/
|
|
|
|
int i;
|
|
|
|
if (direction == READING) {
|
|
/* Copy V1.x inode to the in-core table, swapping bytes if need be. */
|
|
rip->i_mode = (mode_t) conv2(norm, (int) dip->d1_mode);
|
|
rip->i_uid = (uid_t) conv2(norm, (int) dip->d1_uid );
|
|
rip->i_size = (off_t) conv4(norm, dip->d1_size);
|
|
rip->i_mtime = (time_t) conv4(norm, dip->d1_mtime);
|
|
rip->i_atime = (time_t) rip->i_mtime;
|
|
rip->i_ctime = (time_t) rip->i_mtime;
|
|
rip->i_nlinks = (nlink_t) dip->d1_nlinks; /* 1 char */
|
|
rip->i_gid = (gid_t) dip->d1_gid; /* 1 char */
|
|
rip->i_ndzones = V1_NR_DZONES;
|
|
rip->i_nindirs = V1_INDIRECTS;
|
|
for (i = 0; i < V1_NR_TZONES; i++)
|
|
rip->i_zone[i] = (zone_t) conv2(norm, (int) dip->d1_zone[i]);
|
|
} else {
|
|
/* Copying V1.x inode to disk from the in-core table. */
|
|
dip->d1_mode = (u16_t) conv2(norm, (int) rip->i_mode);
|
|
dip->d1_uid = (i16_t) conv2(norm, (int) rip->i_uid );
|
|
dip->d1_size = (i32_t) conv4(norm, rip->i_size);
|
|
dip->d1_mtime = (i32_t) conv4(norm, rip->i_mtime);
|
|
dip->d1_nlinks = (u8_t) rip->i_nlinks; /* 1 char */
|
|
dip->d1_gid = (u8_t) rip->i_gid; /* 1 char */
|
|
for (i = 0; i < V1_NR_TZONES; i++)
|
|
dip->d1_zone[i] = (u16_t) conv2(norm, (int) rip->i_zone[i]);
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* new_icopy *
|
|
*===========================================================================*/
|
|
PRIVATE void new_icopy(rip, dip, direction, norm)
|
|
register struct inode *rip; /* pointer to the in-core inode struct */
|
|
register d2_inode *dip; /* pointer to the d2_inode struct */
|
|
int direction; /* READING (from disk) or WRITING (to disk) */
|
|
int norm; /* TRUE = do not swap bytes; FALSE = swap */
|
|
{
|
|
/* Same as old_icopy, but to/from V2 disk layout. */
|
|
|
|
int i;
|
|
|
|
if (direction == READING) {
|
|
/* Copy V2.x inode to the in-core table, swapping bytes if need be. */
|
|
rip->i_mode = (mode_t) conv2(norm,dip->d2_mode);
|
|
rip->i_uid = (uid_t) conv2(norm,dip->d2_uid);
|
|
rip->i_nlinks = (nlink_t) conv2(norm,dip->d2_nlinks);
|
|
rip->i_gid = (gid_t) conv2(norm,dip->d2_gid);
|
|
rip->i_size = (off_t) conv4(norm,dip->d2_size);
|
|
rip->i_atime = (time_t) conv4(norm,dip->d2_atime);
|
|
rip->i_ctime = (time_t) conv4(norm,dip->d2_ctime);
|
|
rip->i_mtime = (time_t) conv4(norm,dip->d2_mtime);
|
|
rip->i_ndzones = V2_NR_DZONES;
|
|
rip->i_nindirs = V2_INDIRECTS(rip->i_sp->s_block_size);
|
|
for (i = 0; i < V2_NR_TZONES; i++)
|
|
rip->i_zone[i] = (zone_t) conv4(norm, (long) dip->d2_zone[i]);
|
|
} else {
|
|
/* Copying V2.x inode to disk from the in-core table. */
|
|
dip->d2_mode = (u16_t) conv2(norm,rip->i_mode);
|
|
dip->d2_uid = (i16_t) conv2(norm,rip->i_uid);
|
|
dip->d2_nlinks = (u16_t) conv2(norm,rip->i_nlinks);
|
|
dip->d2_gid = (u16_t) conv2(norm,rip->i_gid);
|
|
dip->d2_size = (i32_t) conv4(norm,rip->i_size);
|
|
dip->d2_atime = (i32_t) conv4(norm,rip->i_atime);
|
|
dip->d2_ctime = (i32_t) conv4(norm,rip->i_ctime);
|
|
dip->d2_mtime = (i32_t) conv4(norm,rip->i_mtime);
|
|
for (i = 0; i < V2_NR_TZONES; i++)
|
|
dip->d2_zone[i] = (zone_t) conv4(norm, (long) rip->i_zone[i]);
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* dup_inode *
|
|
*===========================================================================*/
|
|
PUBLIC void dup_inode(ip)
|
|
struct inode *ip; /* The inode to be duplicated. */
|
|
{
|
|
/* This routine is a simplified form of get_inode() for the case where
|
|
* the inode pointer is already known.
|
|
*/
|
|
|
|
ip->i_count++;
|
|
}
|
|
|